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  1. Sep 22, 2020
    • David Hildenbrand's avatar
      mm/memory_hotplug: shrink zones when offlining memory · 8de9a7ef
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 86834898d5a5e5aef9ae6d285201f2d99a4eb300
      
      --------------------------------
      
      commit feee6b29 upstream.
      
      -- snip --
      
      - Missing arm64 hot(un)plug support
      - Missing some vmem_altmap_offset() cleanups
      - Missing sub-section hotadd support
      - Missing unification of mm/hmm.c and kernel/memremap.c
      
      -- snip --
      
      We currently try to shrink a single zone when removing memory.  We use
      the zone of the first page of the memory we are removing.  If that
      memmap was never initialized (e.g., memory was never onlined), we will
      read garbage and can trigger kernel BUGs (due to a stale pointer):
      
          BUG: unable to handle page fault for address: 000000000000353d
          #PF: supervisor write access in kernel mode
          #PF: error_code(0x0002) - not-present page
          PGD 0 P4D 0
          Oops: 0002 [#1] SMP PTI
          CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317
          Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4
          Workqueue: kacpi_hotplug acpi_hotplug_work_fn
          RIP: 0010:clear_zone_contiguous+0x5/0x10
          Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840
          RSP: 0018:ffffad2400043c98 EFLAGS: 00010246
          RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000
          RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40
          RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001
          R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000
          R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680
          FS:  0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000
          CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
          CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0
          DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
          DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
          Call Trace:
           __remove_pages+0x4b/0x640
           arch_remove_memory+0x63/0x8d
           try_remove_memory+0xdb/0x130
           __remove_memory+0xa/0x11
           acpi_memory_device_remove+0x70/0x100
           acpi_bus_trim+0x55/0x90
           acpi_device_hotplug+0x227/0x3a0
           acpi_hotplug_work_fn+0x1a/0x30
           process_one_work+0x221/0x550
           worker_thread+0x50/0x3b0
           kthread+0x105/0x140
           ret_from_fork+0x3a/0x50
          Modules linked in:
          CR2: 000000000000353d
      
      Instead, shrink the zones when offlining memory or when onlining failed.
      Introduce and use remove_pfn_range_from_zone(() for that.  We now
      properly shrink the zones, even if we have DIMMs whereby
      
       - Some memory blocks fall into no zone (never onlined)
      
       - Some memory blocks fall into multiple zones (offlined+re-onlined)
      
       - Multiple memory blocks that fall into different zones
      
      Drop the zone parameter (with a potential dubious value) from
      __remove_pages() and __remove_section().
      
      Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com
      
      
      Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online")	[visible after d0dc12e8]
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
      Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: <stable@vger.kernel.org>	[5.0+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      [yyl: drop the zone parameter in arch/arm64/mm/mmu.c]
      
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      8de9a7ef
    • David Hildenbrand's avatar
      mm/memory_hotplug: fix try_offline_node() · 25086651
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit d98d053efa65169c4e29b8b477cd5bc2b7aef513
      
      --------------------------------
      
      commit 2c91f8fc upstream.
      
      -- snip --
      
      Only contextual issues:
      - Unrelated check_and_unmap_cpu_on_node() changes are missing.
      - Unrelated walk_memory_blocks() has not been moved/refactored yet.
      
      -- snip --
      
      try_offline_node() is pretty much broken right now:
      
       - The node span is updated when onlining memory, not when adding it. We
         ignore memory that was mever onlined. Bad.
      
       - We touch possible garbage memmaps. The pfn_to_nid(pfn) can easily
         trigger a kernel panic. Bad for memory that is offline but also bad
         for subsection hotadd with ZONE_DEVICE, whereby the memmap of the
         first PFN of a section might contain garbage.
      
       - Sections belonging to mixed nodes are not properly considered.
      
      As memory blocks might belong to multiple nodes, we would have to walk
      all pageblocks (or at least subsections) within present sections.
      However, we don't have a way to identify whether a memmap that is not
      online was initialized (relevant for ZONE_DEVICE).  This makes things
      more complicated.
      
      Luckily, we can piggy pack on the node span and the nid stored in memory
      blocks.  Currently, the node span is grown when calling
      move_pfn_range_to_zone() - e.g., when onlining memory, and shrunk when
      removing memory, before calling try_offline_node().  Sysfs links are
      created via link_mem_sections(), e.g., during boot or when adding
      memory.
      
      If the node still spans memory or if any memory block belongs to the
      nid, we don't set the node offline.  As memory blocks that span multiple
      nodes cannot get offlined, the nid stored in memory blocks is reliable
      enough (for such online memory blocks, the node still spans the memory).
      
      Introduce for_each_memory_block() to efficiently walk all memory blocks.
      
      Note: We will soon stop shrinking the ZONE_DEVICE zone and the node span
      when removing ZONE_DEVICE memory to fix similar issues (access of
      garbage memmaps) - until we have a reliable way to identify whether
      these memmaps were properly initialized.  This implies later, that once
      a node had ZONE_DEVICE memory, we won't be able to set a node offline -
      which should be acceptable.
      
      Since commit f1dd2cd1 ("mm, memory_hotplug: do not associate
      hotadded memory to zones until online") memory that is added is not
      assoziated with a zone/node (memmap not initialized).  The introducing
      commit 60a5a19e ("memory-hotplug: remove sysfs file of node")
      already missed that we could have multiple nodes for a section and that
      the zone/node span is updated when onlining pages, not when adding them.
      
      I tested this by hotplugging two DIMMs to a memory-less and cpu-less
      NUMA node.  The node is properly onlined when adding the DIMMs.  When
      removing the DIMMs, the node is properly offlined.
      
      Masayoshi Mizuma reported:
      
      : Without this patch, memory hotplug fails as panic:
      :
      :  BUG: kernel NULL pointer dereference, address: 0000000000000000
      :  ...
      :  Call Trace:
      :   remove_memory_block_devices+0x81/0xc0
      :   try_remove_memory+0xb4/0x130
      :   __remove_memory+0xa/0x20
      :   acpi_memory_device_remove+0x84/0x100
      :   acpi_bus_trim+0x57/0x90
      :   acpi_bus_trim+0x2e/0x90
      :   acpi_device_hotplug+0x2b2/0x4d0
      :   acpi_hotplug_work_fn+0x1a/0x30
      :   process_one_work+0x171/0x380
      :   worker_thread+0x49/0x3f0
      :   kthread+0xf8/0x130
      :   ret_from_fork+0x35/0x40
      
      [david@redhat.com: v3]
        Link: http://lkml.kernel.org/r/20191102120221.7553-1-david@redhat.com
      Link: http://lkml.kernel.org/r/20191028105458.28320-1-david@redhat.com
      
      
      Fixes: 60a5a19e ("memory-hotplug: remove sysfs file of node")
      Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online") # visiable after d0dc12e8
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Tested-by: default avatarMasayoshi Mizuma <m.mizuma@jp.fujitsu.com>
      Cc: Tang Chen <tangchen@cn.fujitsu.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Keith Busch <keith.busch@intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
      Cc: Jani Nikula <jani.nikula@intel.com>
      Cc: Nayna Jain <nayna@linux.ibm.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Conflicts:
        mm/memory_hotplug.c
      [yyl: adjust context]
      
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      25086651
    • Aneesh Kumar K.V's avatar
      mm/memunmap: don't access uninitialized memmap in memunmap_pages() · af893605
      Aneesh Kumar K.V authored
      stable inclusion
      from linux-4.19.100
      commit f291080659d2bba2a33e65de57e1c2ce11473dac
      
      --------------------------------
      
      commit 77e080e7 upstream.
      
      -- snip --
      
      - Missing mm/hmm.c and kernel/memremap.c unification.
      -- hmm code does not need fixes (no altmap)
      - Missing 7cc7867f ("mm/devm_memremap_pages: enable sub-section remap")
      
      -- snip --
      
      Patch series "mm/memory_hotplug: Shrink zones before removing memory",
      v6.
      
      This series fixes the access of uninitialized memmaps when shrinking
      zones/nodes and when removing memory.  Also, it contains all fixes for
      crashes that can be triggered when removing certain namespace using
      memunmap_pages() - ZONE_DEVICE, reported by Aneesh.
      
      We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be
      more involved (we don't have SECTION_IS_ONLINE as an indicator), and
      shrinking is only of limited use (set_zone_contiguous() cannot detect
      the ZONE_DEVICE as contiguous).
      
      We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount
      of code to a minimum.  Shrinking is especially necessary to keep
      zone->contiguous set where possible, especially, on memory unplug of
      DIMMs at zone boundaries.
      
      --------------------------------------------------------------------------
      
      Zones are now properly shrunk when offlining memory blocks or when
      onlining failed.  This allows to properly shrink zones on memory unplug
      even if the separate memory blocks of a DIMM were onlined to different
      zones or re-onlined to a different zone after offlining.
      
      Example:
      
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  0
                present  0
                managed  0
        :/# echo "online_movable" > /sys/devices/system/memory/memory41/state
        :/# echo "online_movable" > /sys/devices/system/memory/memory43/state
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  98304
                present  65536
                managed  65536
        :/# echo 0 > /sys/devices/system/memory/memory43/online
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  32768
                present  32768
                managed  32768
        :/# echo 0 > /sys/devices/system/memory/memory41/online
        :/# cat /proc/zoneinfo
        Node 1, zone  Movable
                spanned  0
                present  0
                managed  0
      
      This patch (of 10):
      
      With an altmap, the memmap falling into the reserved altmap space are not
      initialized and, therefore, contain a garbage NID and a garbage zone.
      Make sure to read the NID/zone from a memmap that was initialized.
      
      This fixes a kernel crash that is observed when destroying a namespace:
      
        kernel BUG at include/linux/mm.h:1107!
        cpu 0x1: Vector: 700 (Program Check) at [c000000274087890]
            pc: c0000000004b9728: memunmap_pages+0x238/0x340
            lr: c0000000004b9724: memunmap_pages+0x234/0x340
        ...
            pid   = 3669, comm = ndctl
        kernel BUG at include/linux/mm.h:1107!
          devm_action_release+0x30/0x50
          release_nodes+0x268/0x2d0
          device_release_driver_internal+0x174/0x240
          unbind_store+0x13c/0x190
          drv_attr_store+0x44/0x60
          sysfs_kf_write+0x70/0xa0
          kernfs_fop_write+0x1ac/0x290
          __vfs_write+0x3c/0x70
          vfs_write+0xe4/0x200
          ksys_write+0x7c/0x140
          system_call+0x5c/0x68
      
      The "page_zone(pfn_to_page(pfn)" was introduced by 69324b8f ("mm,
      devm_memremap_pages: add MEMORY_DEVICE_PRIVATE support"), however, I
      think we will never have driver reserved memory with
      MEMORY_DEVICE_PRIVATE (no altmap AFAIKS).
      
      [david@redhat.com: minimze code changes, rephrase description]
      Link: http://lkml.kernel.org/r/20191006085646.5768-2-david@redhat.com
      
      
      Fixes: 2c2a5af6 ("mm, memory_hotplug: add nid parameter to arch_remove_memory")
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Jason Gunthorpe <jgg@ziepe.ca>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Ira Weiny <ira.weiny@intel.com>
      Cc: Damian Tometzki <damian.tometzki@gmail.com>
      Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Christian Borntraeger <borntraeger@de.ibm.com>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Halil Pasic <pasic@linux.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Pankaj Gupta <pagupta@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Steve Capper <steve.capper@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tom Lendacky <thomas.lendacky@amd.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Wei Yang <richardw.yang@linux.intel.com>
      Cc: Will Deacon <will@kernel.org>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Cc: <stable@vger.kernel.org>	[5.0+]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      af893605
    • David Hildenbrand's avatar
      drivers/base/node.c: simplify unregister_memory_block_under_nodes() · 4486b068
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit d830a11c6279c416424e0981b241e58bf51c7c8b
      
      --------------------------------
      
      commit d84f2f5a upstream.
      
      We don't allow to offline memory block devices that belong to multiple
      numa nodes.  Therefore, such devices can never get removed.  It is
      sufficient to process a single node when removing the memory block.  No
      need to iterate over each and every PFN.
      
      We already have the nid stored for each memory block.  Make sure that the
      nid always has a sane value.
      
      Please note that checking for node_online(nid) is not required.  If we
      would have a memory block belonging to a node that is no longer offline,
      then we would have a BUG in the node offlining code.
      
      Link: http://lkml.kernel.org/r/20190719135244.15242-1-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      4486b068
    • Dan Williams's avatar
      mm/hotplug: kill is_dev_zone() usage in __remove_pages() · 74334f69
      Dan Williams authored
      stable inclusion
      from linux-4.19.100
      commit b9cda6501a340c5d15487575a68454748e3132a4
      
      --------------------------------
      
      commit 96da4350 upstream.
      
      -- snip --
      
      Minor conflict, keep the altmap check.
      
      -- snip --
      
      The zone type check was a leftover from the cleanup that plumbed altmap
      through the memory hotplug path, i.e.  commit da024512 "mm: pass the
      vmem_altmap to arch_remove_memory and __remove_pages".
      
      Link: http://lkml.kernel.org/r/156092352642.979959.6664333788149363039.stgit@dwillia2-desk3.amr.corp.intel.com
      
      
      Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>	[ppc64]
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Jane Chu <jane.chu@oracle.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Jérôme Glisse <jglisse@redhat.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Toshi Kani <toshi.kani@hpe.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Wei Yang <richardw.yang@linux.intel.com>
      Cc: Jason Gunthorpe <jgg@mellanox.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      74334f69
    • David Hildenbrand's avatar
      mm/memory_hotplug: remove "zone" parameter from sparse_remove_one_section · 457dd3c8
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit dc6be8597c8c2959a7ba0c7cc809094d5dd8d99a
      
      --------------------------------
      
      commit b9bf8d34 upstream.
      
      The parameter is unused, so let's drop it.  Memory removal paths should
      never care about zones.  This is the job of memory offlining and will
      require more refactorings.
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-12-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
      Reviewed-by: default avatarWei Yang <richardw.yang@linux.intel.com>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      457dd3c8
    • David Hildenbrand's avatar
      mm/memory_hotplug: make unregister_memory_block_under_nodes() never fail · 3b0f0dae
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 030d045dc067c6b67e4fb4a69e56d7cbda1b1f65
      
      --------------------------------
      
      commit a31b264c upstream.
      
      We really don't want anything during memory hotunplug to fail.  We
      always pass a valid memory block device, that check can go.  Avoid
      allocating memory and eventually failing.  As we are always called under
      lock, we can use a static piece of memory.  This avoids having to put
      the structure onto the stack, having to guess about the stack size of
      callers.
      
      Patch inspired by a patch from Oscar Salvador.
      
      In the future, there might be no need to iterate over nodes at all.
      mem->nid should tell us exactly what to remove.  Memory block devices
      with mixed nodes (added during boot) should properly fenced off and
      never removed.
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-11-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarWei Yang <richardw.yang@linux.intel.com>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      3b0f0dae
    • David Hildenbrand's avatar
      mm/memory_hotplug: remove memory block devices before arch_remove_memory() · 05065fee
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit d883abbc097e9e86ffba1342c6972ebdda06a127
      
      --------------------------------
      
      commit 4c4b7f9b upstream.
      
      Let's factor out removing of memory block devices, which is only
      necessary for memory added via add_memory() and friends that created
      memory block devices.  Remove the devices before calling
      arch_remove_memory().
      
      This finishes factoring out memory block device handling from
      arch_add_memory() and arch_remove_memory().
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-10-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      05065fee
    • David Hildenbrand's avatar
      mm/memory_hotplug: create memory block devices after arch_add_memory() · 569f3192
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit aa49b6abcefc9baf8d254f75ed19c38b6866951f
      
      --------------------------------
      
      commit db051a0d upstream.
      
      Only memory to be added to the buddy and to be onlined/offlined by user
      space using /sys/devices/system/memory/...  needs (and should have!)
      memory block devices.
      
      Factor out creation of memory block devices.  Create all devices after
      arch_add_memory() succeeded.  We can later drop the want_memblock
      parameter, because it is now effectively stale.
      
      Only after memory block devices have been added, memory can be onlined
      by user space.  This implies, that memory is not visible to user space
      at all before arch_add_memory() succeeded.
      
      While at it
       - use WARN_ON_ONCE instead of BUG_ON in moved unregister_memory()
       - introduce find_memory_block_by_id() to search via block id
       - Use find_memory_block_by_id() in init_memory_block() to catch
         duplicates
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-8-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarPavel Tatashin <pasha.tatashin@soleen.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      569f3192
    • David Hildenbrand's avatar
      drivers/base/memory: pass a block_id to init_memory_block() · e8f59cd5
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 97c60869dbf351d7d9a7dbdeeebdcdd53418c706
      
      --------------------------------
      
      commit 18115825 upstream.
      
      We'll rework hotplug_memory_register() shortly, so it no longer consumes
      pass a section.
      
      [cai@lca.pw: fix a compilation warning]
        Link: http://lkml.kernel.org/r/1559320186-28337-1-git-send-email-cai@lca.pw
      Link: http://lkml.kernel.org/r/20190527111152.16324-6-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarQian Cai <cai@lca.pw>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      e8f59cd5
    • David Hildenbrand's avatar
      mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVE · 34b64663
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 000a1d59cfe9d6e875462ed72de32770322c282b
      
      --------------------------------
      
      commit 80ec922d upstream.
      
      -- snip --
      
      Missing arm64 memory hot(un)plug support.
      
      -- snip --
      
      We want to improve error handling while adding memory by allowing to use
      arch_remove_memory() and __remove_pages() even if
      CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like:
      
      	arch_add_memory()
      	rc = do_something();
      	if (rc) {
      		arch_remove_memory();
      	}
      
      We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require
      quite some dependencies for memory offlining.
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarPavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      [yyl: remove CONFIG_MEMORY_HOTREMOVE in arch/arm64/mm/mmu.c]
      
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      34b64663
    • David Hildenbrand's avatar
      s390x/mm: implement arch_remove_memory() · 283884fd
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 817edd2bb385aa4bc96f287081bac0d9c99bbf9a
      
      --------------------------------
      
      commit 18c86506 upstream.
      
      Will come in handy when wanting to handle errors after
      arch_add_memory().
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-4-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      283884fd
    • David Hildenbrand's avatar
      mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail · a860e45f
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 5163b1ec3a0c3a2e1e53b7794b64866cd6ba8697
      
      --------------------------------
      
      commit ac5c9426 upstream.
      
      -- snip --
      
      Minor conflict in arch/powerpc/mm/mem.c
      
      -- snip --
      
      All callers of arch_remove_memory() ignore errors.  And we should really
      try to remove any errors from the memory removal path.  No more errors are
      reported from __remove_pages().  BUG() in s390x code in case
      arch_remove_memory() is triggered.  We may implement that properly later.
      WARN in case powerpc code failed to remove the section mapping, which is
      better than ignoring the error completely right now.
      
      Link: http://lkml.kernel.org/r/20190409100148.24703-5-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Stefan Agner <stefan@agner.ch>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Mike Travis <mike.travis@hpe.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      a860e45f
    • Aneesh Kumar K.V's avatar
      powerpc/mm: Fix section mismatch warning · 7c9ee508
      Aneesh Kumar K.V authored
      
      stable inclusion
      from linux-4.19.100
      commit 58ddf0b0eff2a6cb536082fc6b046f5eb51c240c
      
      --------------------------------
      
      commit 26ad2671 upstream.
      
      This patch fix the below section mismatch warnings.
      
      WARNING: vmlinux.o(.text+0x2d1f44): Section mismatch in reference from the function devm_memremap_pages_release() to the function .meminit.text:arch_remove_memory()
      WARNING: vmlinux.o(.text+0x2d265c): Section mismatch in reference from the function devm_memremap_pages() to the function .meminit.text:arch_add_memory()
      
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      7c9ee508
    • David Hildenbrand's avatar
      mm/memory_hotplug: make __remove_section() never fail · b9f9a54e
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit efaa8fb877a081d82c4dcd14e904bdb97f074eeb
      
      --------------------------------
      
      commit 9d1d887d upstream.
      
      Let's just warn in case a section is not valid instead of failing to
      remove somewhere in the middle of the process, returning an error that
      will be mostly ignored by callers.
      
      Link: http://lkml.kernel.org/r/20190409100148.24703-4-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Mike Travis <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Stefan Agner <stefan@agner.ch>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      b9f9a54e
    • David Hildenbrand's avatar
      mm/memory_hotplug: make unregister_memory_section() never fail · d922904c
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 36976713c4d781e42b27eddd16d91ce023caf669
      
      --------------------------------
      
      commit cb7b3a36 upstream.
      
      Failing while removing memory is mostly ignored and cannot really be
      handled.  Let's treat errors in unregister_memory_section() in a nice way,
      warning, but continuing.
      
      Link: http://lkml.kernel.org/r/20190409100148.24703-3-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Mike Travis <mike.travis@hpe.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Stefan Agner <stefan@agner.ch>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      d922904c
    • Dan Carpenter's avatar
      mm, memory_hotplug: update a comment in unregister_memory() · 309f074c
      Dan Carpenter authored
      
      stable inclusion
      from linux-4.19.100
      commit 8893b51a89600e6a8d7d79f397b6427edb508f7b
      
      --------------------------------
      
      commit 16df1456 upstream.
      
      The remove_memory_block() function was renamed to in commit
      cc292b0b ("drivers/base/memory.c: rename remove_memory_block() to
      remove_memory_section()").
      
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      309f074c
    • Baoquan He's avatar
      drivers/base/memory.c: clean up relics in function parameters · b120d3a9
      Baoquan He authored
      stable inclusion
      from linux-4.19.100
      commit 9e59baa2da6d025851b130e9f294cb3605395a2e
      
      --------------------------------
      
      commit 063b8a4c upstream.
      
      The input parameter 'phys_index' of memory_block_action() is actually the
      section number, but not the phys_index of memory_block.  This is a relic
      from the past when one memory block could only contain one section.
      Rename it to start_section_nr.
      
      And also in remove_memory_section(), the 'node_id' and 'phys_device'
      arguments are not used by anyone.  Remove them.
      
      Link: http://lkml.kernel.org/r/20190329144250.14315-2-bhe@redhat.com
      
      
      Signed-off-by: default avatarBaoquan He <bhe@redhat.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Reviewed-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Reviewed-by: default avatarMukesh Ojha <mojha@codeaurora.org>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      b120d3a9
    • David Hildenbrand's avatar
      mm/memory_hotplug: release memory resource after arch_remove_memory() · a86124c1
      David Hildenbrand authored
      stable inclusion
      from linux-4.19.100
      commit 2ad264f6887334550a8137c04d955992391e3e4c
      
      --------------------------------
      
      commit d9eb1417 upstream.
      
      Patch series "mm/memory_hotplug: Better error handling when removing
      memory", v1.
      
      Error handling when removing memory is somewhat messed up right now.  Some
      errors result in warnings, others are completely ignored.  Memory unplug
      code can essentially not deal with errors properly as of now.
      remove_memory() will never fail.
      
      We have basically two choices:
      1. Allow arch_remov_memory() and friends to fail, propagating errors via
         remove_memory(). Might be problematic (e.g. DIMMs consisting of multiple
         pieces added/removed separately).
      2. Don't allow the functions to fail, handling errors in a nicer way.
      
      It seems like most errors that can theoretically happen are really corner
      cases and mostly theoretical (e.g.  "section not valid").  However e.g.
      aborting removal of sections while all callers simply continue in case of
      errors is not nice.
      
      If we can gurantee that removal of memory always works (and WARN/skip in
      case of theoretical errors so we can figure out what is going on), we can
      go ahead and implement better error handling when adding memory.
      
      E.g. via add_memory():
      
      arch_add_memory()
      ret = do_stuff()
      if (ret) {
      	arch_remove_memory();
      	goto error;
      }
      
      Handling here that arch_remove_memory() might fail is basically
      impossible.  So I suggest, let's avoid reporting errors while removing
      memory, warning on theoretical errors instead and continuing instead of
      aborting.
      
      This patch (of 4):
      
      __add_pages() doesn't add the memory resource, so __remove_pages()
      shouldn't remove it.  Let's factor it out.  Especially as it is a special
      case for memory used as system memory, added via add_memory() and friends.
      
      We now remove the resource after removing the sections instead of doing it
      the other way around.  I don't think this change is problematic.
      
      add_memory()
      	register memory resource
      	arch_add_memory()
      
      remove_memory
      	arch_remove_memory()
      	release memory resource
      
      While at it, explain why we ignore errors and that it only happeny if
      we remove memory in a different granularity as we added it.
      
      [david@redhat.com: fix printk warning]
        Link: http://lkml.kernel.org/r/20190417120204.6997-1-david@redhat.com
      Link: http://lkml.kernel.org/r/20190409100148.24703-2-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Mike Travis <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Stefan Agner <stefan@agner.ch>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      a86124c1
    • Oscar Salvador's avatar
      mm, memory_hotplug: add nid parameter to arch_remove_memory · 1ef436b7
      Oscar Salvador authored
      stable inclusion
      from linux-4.19.100
      commit 5c1f8f5358e8cd501245ee0e954dc0c0b231d6a2
      
      --------------------------------
      
      commit 2c2a5af6 upstream.
      
      -- snip --
      
      Missing unification of mm/hmm.c and kernel/memremap.c
      
      -- snip --
      
      Patch series "Do not touch pages in hot-remove path", v2.
      
      This patchset aims for two things:
      
       1) A better definition about offline and hot-remove stage
       2) Solving bugs where we can access non-initialized pages
          during hot-remove operations [2] [3].
      
      This is achieved by moving all page/zone handling to the offline
      stage, so we do not need to access pages when hot-removing memory.
      
      [1] https://patchwork.kernel.org/cover/10691415/
      [2] https://patchwork.kernel.org/patch/10547445/
      [3] https://www.spinics.net/lists/linux-mm/msg161316.html
      
      This patch (of 5):
      
      This is a preparation for the following-up patches.  The idea of passing
      the nid is that it will allow us to get rid of the zone parameter
      afterwards.
      
      Link: http://lkml.kernel.org/r/20181127162005.15833-2-osalvador@suse.de
      
      
      Signed-off-by: default avatarOscar Salvador <osalvador@suse.de>
      Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarPavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Jerome Glisse <jglisse@redhat.com>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      1ef436b7
    • Wei Yang's avatar
      drivers/base/memory.c: remove an unnecessary check on NR_MEM_SECTIONS · 7fe25a0a
      Wei Yang authored
      stable inclusion
      from linux-4.19.100
      commit 4149c8693a8c23947cb60d7c1d177e9d93e6481e
      
      --------------------------------
      
      commit 3b6fd6ff upstream.
      
      In cb5e39b8 ("drivers: base: refactor add_memory_section() to
      add_memory_block()"), add_memory_block() is introduced, which is only
      invoked in memory_dev_init().
      
      When combining these two loops in memory_dev_init() and
      add_memory_block(), they looks like this:
      
          for (i = 0; i < NR_MEM_SECTIONS; i += sections_per_block)
              for (j = i;
      	    (j < i + sections_per_block) && j < NR_MEM_SECTIONS;
      	    j++)
      
      Since it is sure the (i < NR_MEM_SECTIONS) and j sits in its own memory
      block, the check of (j < NR_MEM_SECTIONS) is not necessary.
      
      This patch just removes this check.
      
      Link: http://lkml.kernel.org/r/20181123222811.18216-1-richard.weiyang@gmail.com
      
      
      Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Seth Jennings <sjenning@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      7fe25a0a
    • Wei Yang's avatar
      mm, sparse: pass nid instead of pgdat to sparse_add_one_section() · 44feb957
      Wei Yang authored
      stable inclusion
      from linux-4.19.100
      commit aa2e8b68f24462ceb1c495cbde642a174c80fe55
      
      --------------------------------
      
      commit 4e0d2e7e upstream.
      
      Since the information needed in sparse_add_one_section() is node id to
      allocate proper memory, it is not necessary to pass its pgdat.
      
      This patch changes the prototype of sparse_add_one_section() to pass node
      id directly.  This is intended to reduce misleading that
      sparse_add_one_section() would touch pgdat.
      
      Link: http://lkml.kernel.org/r/20181204085657.20472-2-richard.weiyang@gmail.com
      
      
      Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
      Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      44feb957
    • Wei Yang's avatar
      mm, sparse: drop pgdat_resize_lock in sparse_add/remove_one_section() · 0706d884
      Wei Yang authored
      stable inclusion
      from linux-4.19.100
      commit b1dbaa19162857eeb8cd751e58394d1c8c34b12e
      
      --------------------------------
      
      commit 83af6588 upstream.
      
      pgdat_resize_lock is used to protect pgdat's memory region information
      like: node_start_pfn, node_present_pages, etc.  While in function
      sparse_add/remove_one_section(), pgdat_resize_lock is used to protect
      initialization/release of one mem_section.  This looks not proper.
      
      These code paths are currently protected by mem_hotplug_lock currently but
      should there ever be any reason for locking at the sparse layer a
      dedicated lock should be introduced.
      
      Following is the current call trace of sparse_add/remove_one_section()
      
          mem_hotplug_begin()
          arch_add_memory()
             add_pages()
                 __add_pages()
                     __add_section()
                         sparse_add_one_section()
          mem_hotplug_done()
      
          mem_hotplug_begin()
          arch_remove_memory()
              __remove_pages()
                  __remove_section()
                      sparse_remove_one_section()
          mem_hotplug_done()
      
      The comment above the pgdat_resize_lock also mentions "Holding this will
      also guarantee that any pfn_valid() stays that way.", which is true with
      the current implementation and false after this patch.  But current
      implementation doesn't meet this comment.  There isn't any pfn walkers to
      take the lock so this looks like a relict from the past.  This patch also
      removes this comment.
      
      [richard.weiyang@gmail.com: v4]
        Link: http://lkml.kernel.org/r/20181204085657.20472-1-richard.weiyang@gmail.com
      [mhocko@suse.com: changelog suggestion]
      Link: http://lkml.kernel.org/r/20181128091243.19249-1-richard.weiyang@gmail.com
      
      
      Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
      Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      0706d884
    • David Hildenbrand's avatar
      arm64/mm: add temporary arch_remove_memory() implementation · ddf894cb
      David Hildenbrand authored
      mainline inclusion
      from mainline-5.3-rc1
      commit 22eb6346
      category: bugfix
      bugzilla: 29418
      CVE: NA
      
      -------------------------------------------------
      
      A proper arch_remove_memory() implementation is on its way, which also
      cleanly removes page tables in arch_add_memory() in case something goes
      wrong.
      
      As we want to use arch_remove_memory() in case something goes wrong
      during memory hotplug after arch_add_memory() finished, let's add a
      temporary hack that is sufficient enough until we get a proper
      implementation that cleans up page table entries.
      
      We will remove CONFIG_MEMORY_HOTREMOVE around this code in follow up
      patches.
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-5-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: Yu Zhao <yuzhao@google.com>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      ddf894cb
    • David Hildenbrand's avatar
      s390x/mm: fail when an altmap is used for arch_add_memory() · 9d5907de
      David Hildenbrand authored
      mainline inclusion
      from mainline-5.3-rc1
      commit 973de24a
      category: bugfix
      bugzilla: 29418
      CVE: NA
      
      -------------------------------------------------
      
      ZONE_DEVICE is not yet supported, fail if an altmap is passed, so we
      don't forget arch_add_memory()/arch_remove_memory() when unlocking
      support.
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-3-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Suggested-by: default avatarDan Williams <dan.j.williams@intel.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Oscar Salvador <osalvador@suse.com>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Qian Cai <cai@lca.pw>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Wei Yang <richard.weiyang@gmail.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      9d5907de
    • David Hildenbrand's avatar
      mm/memory_hotplug: simplify and fix check_hotplug_memory_range() · 574a1b92
      David Hildenbrand authored
      mainline inclusion
      from mainline-5.3-rc1
      commit cec3ebd0
      category: bugfix
      bugzilla: 29418
      CVE: NA
      
      -------------------------------------------------
      
      Patch series "mm/memory_hotplug: Factor out memory block devicehandling", v3.
      
      We only want memory block devices for memory to be onlined/offlined
      (add/remove from the buddy).  This is required so user space can
      online/offline memory and kdump gets notified about newly onlined
      memory.
      
      Let's factor out creation/removal of memory block devices.  This helps
      to further cleanup arch_add_memory/arch_remove_memory() and to make
      implementation of new features easier - especially sub-section memory
      hot add from Dan.
      
      Anshuman Khandual is currently working on arch_remove_memory().  I added
      a temporary solution via "arm64/mm: Add temporary arch_remove_memory()
      implementation", that is sufficient as a firsts tep in the context of
      this series.  (we don't cleanup page tables in case anything goes wrong
      already)
      
      Did a quick sanity test with DIMM plug/unplug, making sure all devices
      and sysfs links properly get added/removed.  Compile tested on s390x and
      x86-64.
      
      This patch (of 11):
      
      By converting start and size to page granularity, we actually ignore
      unaligned parts within a page instead of properly bailing out with an
      error.
      
      Link: http://lkml.kernel.org/r/20190527111152.16324-2-david@redhat.com
      
      
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
      Reviewed-by: default avatarWei Yang <richardw.yang@linux.intel.com>
      Reviewed-by: default avatarPavel Tatashin <pasha.tatashin@soleen.com>
      Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Qian Cai <cai@lca.pw>
      Cc: Arun KS <arunks@codeaurora.org>
      Cc: Mathieu Malaterre <malat@debian.org>
      Cc: Alex Deucher <alexander.deucher@amd.com>
      Cc: Andrew Banman <andrew.banman@hpe.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Anshuman Khandual <anshuman.khandual@arm.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chintan Pandya <cpandya@codeaurora.org>
      Cc: Christophe Leroy <christophe.leroy@c-s.fr>
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Jun Yao <yaojun8558363@gmail.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Logan Gunthorpe <logang@deltatee.com>
      Cc: Mark Brown <broonie@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Rob Herring <robh@kernel.org>
      Cc: Robin Murphy <robin.murphy@arm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Gorbik <gor@linux.ibm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Yu Zhao <yuzhao@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      574a1b92
    • Bo Wu's avatar
      scsi: iscsi: Avoid potential deadlock in iscsi_if_rx func · e325eeef
      Bo Wu authored
      stable inclusion
      from linux-4.19.100
      commit a76e62517465d984f672b9e85e7d96e02a451e6b
      
      --------------------------------
      
      commit bba340c7 upstream.
      
      In iscsi_if_rx func, after receiving one request through
      iscsi_if_recv_msg func, iscsi_if_send_reply will be called to try to
      reply to the request in a do-while loop.  If the iscsi_if_send_reply
      function keeps returning -EAGAIN, a deadlock will occur.
      
      For example, a client only send msg without calling recvmsg func, then
      it will result in the watchdog soft lockup.  The details are given as
      follows:
      
      	sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ISCSI);
      	retval = bind(sock_fd, (struct sock addr*) & src_addr, sizeof(src_addr);
      	while (1) {
      		state_msg = sendmsg(sock_fd, &msg, 0);
      		//Note: recvmsg(sock_fd, &msg, 0) is not processed here.
      	}
      	close(sock_fd);
      
      watchdog: BUG: soft lockup - CPU#7 stuck for 22s! [netlink_test:253305] Sample time: 4000897528 ns(HZ: 250) Sample stat:
      curr: user: 675503481560, nice: 321724050, sys: 448689506750, idle: 4654054240530, iowait: 40885550700, irq: 14161174020, softirq: 8104324140, st: 0
      deta: user: 0, nice: 0, sys: 3998210100, idle: 0, iowait: 0, irq: 1547170, softirq: 242870, st: 0 Sample softirq:
               TIMER:        992
               SCHED:          8
      Sample irqstat:
               irq    2: delta       1003, curr:    3103802, arch_timer
      CPU: 7 PID: 253305 Comm: netlink_test Kdump: loaded Tainted: G           OE
      Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
      pstate: 40400005 (nZcv daif +PAN -UAO)
      pc : __alloc_skb+0x104/0x1b0
      lr : __alloc_skb+0x9c/0x1b0
      sp : ffff000033603a30
      x29: ffff000033603a30 x28: 00000000000002dd
      x27: ffff800b34ced810 x26: ffff800ba7569f00
      x25: 00000000ffffffff x24: 0000000000000000
      x23: ffff800f7c43f600 x22: 0000000000480020
      x21: ffff0000091d9000 x20: ffff800b34eff200
      x19: ffff800ba7569f00 x18: 0000000000000000
      x17: 0000000000000000 x16: 0000000000000000
      x15: 0000000000000000 x14: 0001000101000100
      x13: 0000000101010000 x12: 0101000001010100
      x11: 0001010101010001 x10: 00000000000002dd
      x9 : ffff000033603d58 x8 : ffff800b34eff400
      x7 : ffff800ba7569200 x6 : ffff800b34eff400
      x5 : 0000000000000000 x4 : 00000000ffffffff
      x3 : 0000000000000000 x2 : 0000000000000001
      x1 : ffff800b34eff2c0 x0 : 0000000000000300 Call trace:
      __alloc_skb+0x104/0x1b0
      iscsi_if_rx+0x144/0x12bc [scsi_transport_iscsi]
      netlink_unicast+0x1e0/0x258
      netlink_sendmsg+0x310/0x378
      sock_sendmsg+0x4c/0x70
      sock_write_iter+0x90/0xf0
      __vfs_write+0x11c/0x190
      vfs_write+0xac/0x1c0
      ksys_write+0x6c/0xd8
      __arm64_sys_write+0x24/0x30
      el0_svc_common+0x78/0x130
      el0_svc_handler+0x38/0x78
      el0_svc+0x8/0xc
      
      Link: https://lore.kernel.org/r/EDBAAA0BBBA2AC4E9C8B6B81DEEE1D6915E3D4D2@dggeml505-mbx.china.huawei.com
      
      
      Signed-off-by: default avatarBo Wu <wubo40@huawei.com>
      Reviewed-by: default avatarZhiqiang Liu <liuzhiqiang26@huawei.com>
      Reviewed-by: default avatarLee Duncan <lduncan@suse.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      e325eeef
    • Masato Suzuki's avatar
      sd: Fix REQ_OP_ZONE_REPORT completion handling · d0a154af
      Masato Suzuki authored
      
      stable inclusion
      from linux-4.19.100
      commit 8d9aa36cc7acdd106225d323da17e6015a6e4d2f
      
      --------------------------------
      
      ZBC/ZAC report zones command may return less bytes than requested if the
      number of matching zones for the report request is small. However, unlike
      read or write commands, the remainder of incomplete report zones commands
      cannot be automatically requested by the block layer: the start sector of
      the next report cannot be known, and the report reply may not be 512B
      aligned for SAS drives (a report zone reply size is always a multiple of
      64B). The regular request completion code executing bio_advance() and
      restart of the command remainder part currently causes invalid zone
      descriptor data to be reported to the caller if the report zone size is
      smaller than 512B (a case that can happen easily for a report of the last
      zones of a SAS drive for example).
      
      Since blkdev_report_zones() handles report zone command processing in a
      loop until completion (no more zones are being reported), we can safely
      avoid that the block layer performs an incorrect bio_advance() call and
      restart of the remainder of incomplete report zone BIOs. To do so, always
      indicate a full completion of REQ_OP_ZONE_REPORT by setting good_bytes to
      the request buffer size and by setting the command resid to 0. This does
      not affect the post processing of the report zone reply done by
      sd_zbc_complete() since the reply header indicates the number of zones
      reported.
      
      Fixes: 89d94756 ("sd: Implement support for ZBC devices")
      Cc: <stable@vger.kernel.org> # 4.19
      Cc: <stable@vger.kernel.org> # 4.14
      Signed-off-by: default avatarMasato Suzuki <masato.suzuki@wdc.com>
      Reviewed-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
      Acked-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      d0a154af
    • Eric Dumazet's avatar
      tun: add mutex_unlock() call and napi.skb clearing in tun_get_user() · 6a1be930
      Eric Dumazet authored
      
      stable inclusion
      from linux-4.19.100
      commit 8f50a05dd6fe2372ac0d5c67645e4e480254ce30
      
      --------------------------------
      
      [ Upstream commit 1efba987 ]
      
      If both IFF_NAPI_FRAGS mode and XDP are enabled, and the XDP program
      consumes the skb, we need to clear the napi.skb (or risk
      a use-after-free) and release the mutex (or risk a deadlock)
      
      WARNING: lock held when returning to user space!
      5.5.0-rc6-syzkaller #0 Not tainted
      ------------------------------------------------
      syz-executor.0/455 is leaving the kernel with locks still held!
      1 lock held by syz-executor.0/455:
       #0: ffff888098f6e748 (&tfile->napi_mutex){+.+.}, at: tun_get_user+0x1604/0x3fc0 drivers/net/tun.c:1835
      
      Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Cc: Petar Penkov <ppenkov@google.com>
      Cc: Willem de Bruijn <willemb@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      6a1be930
    • Alexei Starovoitov's avatar
      bpf: fix BTF limits · 2c652680
      Alexei Starovoitov authored
      
      stable inclusion
      from linux-4.19.99
      commit 62bce3654c9509fc0ccc8a3eb99a1b0a0153e0ec
      
      --------------------------------
      
      [ Upstream commit a0791f0d ]
      
      vmlinux BTF has more than 64k types.
      Its string section is also at the offset larger than 64k.
      Adjust both limits to make in-kernel BTF verifier successfully parse in-kernel BTF.
      
      Fixes: 69b693f0 ("bpf: btf: Introduce BPF Type Format (BTF)")
      Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      2c652680
    • Colin Ian King's avatar
      scsi: libfc: fix null pointer dereference on a null lport · 5f96dc74
      Colin Ian King authored
      
      stable inclusion
      from linux-4.19.99
      commit 8ce259e5b003c0838c12752584254e310ddf3191
      
      --------------------------------
      
      [ Upstream commit 41a6bf65 ]
      
      Currently if lport is null then the null lport pointer is dereference when
      printing out debug via the FC_LPORT_DB macro. Fix this by using the more
      generic FC_LIBFC_DBG debug macro instead that does not use lport.
      
      Addresses-Coverity: ("Dereference after null check")
      Fixes: 7414705e ("libfc: Add runtime debugging with debug_logging module parameter")
      Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      5f96dc74
    • Lu Baolu's avatar
      iommu: Use right function to get group for device · 98aa574d
      Lu Baolu authored
      
      stable inclusion
      from linux-4.19.99
      commit f771e86b02301bf00c92aa87e9994d974414cab7
      
      --------------------------------
      
      [ Upstream commit 57274ea2 ]
      
      The iommu_group_get_for_dev() will allocate a group for a
      device if it isn't in any group. This isn't the use case
      in iommu_request_dm_for_dev(). Let's use iommu_group_get()
      instead.
      
      Fixes: d290f1e7 ("iommu: Introduce iommu_request_dm_for_dev()")
      Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      98aa574d
    • Trond Myklebust's avatar
      NFSv4/flexfiles: Fix invalid deref in FF_LAYOUT_DEVID_NODE() · 4fa2d51c
      Trond Myklebust authored
      
      stable inclusion
      from linux-4.19.99
      commit 9ed8e8f6844dc84ba115c732f5e04c5e8c257422
      
      --------------------------------
      
      [ Upstream commit 108bb4af ]
      
      If the attempt to instantiate the mirror's layout DS pointer failed,
      then that pointer may hold a value of type ERR_PTR(), so we need
      to check that before we dereference it.
      
      Fixes: 65990d1a ("pNFS/flexfiles: Fix a deadlock on LAYOUTGET")
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      4fa2d51c
    • Anna Schumaker's avatar
      NFS: Add missing encode / decode sequence_maxsz to v4.2 operations · d5d07493
      Anna Schumaker authored
      
      stable inclusion
      from linux-4.19.99
      commit 7228d4369190230328c76198214a9071002b3c23
      
      --------------------------------
      
      [ Upstream commit 1a3466ae ]
      
      These really should have been there from the beginning, but we never
      noticed because there was enough slack in the RPC request for the extra
      bytes. Chuck's recent patch to use au_cslack and au_rslack to compute
      buffer size shrunk the buffer enough that this was now a problem for
      SEEK operations on my test client.
      
      Fixes: f4ac1674 ("nfs: Add ALLOCATE support")
      Fixes: 2e72448b ("NFS: Add COPY nfs operation")
      Fixes: cb95deea ("NFS OFFLOAD_CANCEL xdr")
      Fixes: 624bd5b7 ("nfs: Add DEALLOCATE support")
      Fixes: 1c6dcbe5 ("NFS: Implement SEEK")
      Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
      Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      d5d07493
    • Rafael J. Wysocki's avatar
      driver core: Fix PM-runtime for links added during consumer probe · 9e2c53ea
      Rafael J. Wysocki authored
      
      stable inclusion
      from linux-4.19.99
      commit 4fe1e6caac16b7bd20eacc1c363351e5d533ac35
      
      --------------------------------
      
      [ Upstream commit 36003d4c ]
      
      Commit 4c06c4e6 ("driver core: Fix possible supplier PM-usage
      counter imbalance") introduced a regression that causes suppliers
      to be suspended prematurely for device links added during consumer
      driver probe if the initial PM-runtime status of the consumer is
      "suspended" and the consumer is resumed after adding the link and
      before pm_runtime_put_suppliers() is called.  In that case,
      pm_runtime_put_suppliers() will drop the rpm_active refcount for
      the link by one and (since rpm_active is equal to two after the
      preceding consumer resume) the supplier's PM-runtime usage counter
      will be decremented, which may cause the supplier to suspend even
      though the consumer's PM-runtime status is "active".
      
      For this reason, partially revert commit 4c06c4e6 as the problem
      it tried to fix needs to be addressed somewhat differently, and
      change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so
      that the latter only drops rpm_active references acquired by the
      former.  [This requires adding a new field to struct device_link,
      but I coulnd't find a cleaner way to address the issue that would
      work in all cases.]
      
      This causes pm_runtime_put_suppliers() to effectively ignore device
      links added during consumer probe, so device_link_add() doesn't need
      to worry about ensuring that suppliers will remain active after
      pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE
      set and it only needs to bump up rpm_active by one for those links,
      so pm_runtime_active_link() is not necessary any more.
      
      Fixes: 4c06c4e6 ("driver core: Fix possible supplier PM-usage counter imbalance")
      Reported-by: default avatarJon Hunter <jonathanh@nvidia.com>
      Tested-by: default avatarJon Hunter <jonathanh@nvidia.com>
      Tested-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Tested-by: default avatarThierry Reding <treding@nvidia.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      9e2c53ea
    • Rafael J. Wysocki's avatar
      driver core: Fix possible supplier PM-usage counter imbalance · b33c3deb
      Rafael J. Wysocki authored
      
      stable inclusion
      from linux-4.19.99
      commit 3d6b7c14f88f11fd835c1947c149545d393f3fad
      
      --------------------------------
      
      [ Upstream commit 4c06c4e6 ]
      
      If a stateless device link to a certain supplier with
      DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
      consumer driver's probe callback, the supplier's PM-runtime usage
      counter will be nonzero after that which effectively causes the
      supplier to remain "always on" going forward.
      
      Namely, device_link_add() called to add the link invokes
      device_link_rpm_prepare() which notices that the consumer driver is
      probing, so it increments the supplier's PM-runtime usage counter
      with the assumption that the link will stay around until
      pm_runtime_put_suppliers() is called by driver_probe_device(),
      but if the link goes away before that point, the supplier's
      PM-runtime usage counter will remain nonzero.
      
      To prevent that from happening, first rework pm_runtime_get_suppliers()
      and pm_runtime_put_suppliers() to use the rpm_active refounts of device
      links and make the latter only drop rpm_active and the supplier's
      PM-runtime usage counter for each link by one, unless rpm_active is
      one already for it.  Next, modify device_link_add() to bump up the
      new link's rpm_active refcount and the suppliers PM-runtime usage
      counter by two, to prevent pm_runtime_put_suppliers(), if it is
      called subsequently, from suspending the supplier prematurely (in
      case its PM-runtime usage counter goes down to 0 in there).
      
      Due to the way rpm_put_suppliers() works, this change does not
      affect runtime suspend of the consumer ends of new device links (or,
      generally, device links for which DL_FLAG_PM_RUNTIME has just been
      set).
      
      Fixes: e2f3cd83 ("driver core: Fix handling of runtime PM flags in device_link_add()")
      Reported-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Tested-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      b33c3deb
    • Moritz Fischer's avatar
      net: phy: fixed_phy: Fix fixed_phy not checking GPIO · 152ec33b
      Moritz Fischer authored
      
      stable inclusion
      from linux-4.19.99
      commit 57738dd2709835fc45682afa0885a870d62ca51e
      
      --------------------------------
      
      [ Upstream commit 8f289805 ]
      
      Fix fixed_phy not checking GPIO if no link_update callback
      is registered.
      
      In the original version all users registered a link_update
      callback so the issue was masked.
      
      Fixes: a5597008 ("phy: fixed_phy: Add gpio to determine link up/down.")
      Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
      Signed-off-by: default avatarMoritz Fischer <mdf@kernel.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      152ec33b
    • Rafael J. Wysocki's avatar
      driver core: Do not call rpm_put_suppliers() in pm_runtime_drop_link() · cdc8a64a
      Rafael J. Wysocki authored
      
      stable inclusion
      from linux-4.19.99
      commit 02f6982774e25ae57bca56e0062e53c304ba30dc
      
      --------------------------------
      
      [ Upstream commit a1fdbfbb ]
      
      Calling rpm_put_suppliers() from pm_runtime_drop_link() is excessive
      as it affects all suppliers of the consumer device and not just the
      one pointed to by the device link being dropped.  Worst case it may
      cause the consumer device to stop working unexpectedly.  Moreover, in
      principle it is racy with respect to runtime PM of the consumer
      device.
      
      To avoid these problems drop runtime PM references on the particular
      supplier pointed to by the link in question only and do that after
      the link has been dropped from the consumer device's list of links to
      suppliers, which is in device_link_free().
      
      Fixes: a0504aec ("PM / runtime: Drop usage count for suppliers at device link removal")
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      cdc8a64a
    • Rafael J. Wysocki's avatar
      driver core: Fix handling of runtime PM flags in device_link_add() · d5495331
      Rafael J. Wysocki authored
      
      stable inclusion
      from linux-4.19.99
      commit d6a91833c6ed8a95ad1b4a5e2364bb6d4a039f25
      
      --------------------------------
      
      [ Upstream commit e2f3cd83 ]
      
      After commit ead18c23 ("driver core: Introduce device links
      reference counting"), if there is a link between the given supplier
      and the given consumer already, device_link_add() will refcount it
      and return it unconditionally without updating its flags.  It is
      possible, however, that the second (or any subsequent) caller of
      device_link_add() for the same consumer-supplier pair will pass
      DL_FLAG_PM_RUNTIME, possibly along with DL_FLAG_RPM_ACTIVE, in flags
      to it and the existing link may not behave as expected then.
      
      First, if DL_FLAG_PM_RUNTIME is not set in the existing link's flags
      at all, it needs to be set like during the original initialization of
      the link.
      
      Second, if DL_FLAG_RPM_ACTIVE is passed to device_link_add() in flags
      (in addition to DL_FLAG_PM_RUNTIME), the existing link should to be
      updated to reflect the "active" runtime PM configuration of the
      consumer-supplier pair and extra care must be taken here to avoid
      possible destructive races with runtime PM of the consumer.
      
      To that end, redefine the rpm_active field in struct device_link
      as a refcount, initialize it to 1 and make rpm_resume() (for the
      consumer) and device_link_add() increment it whenever they acquire
      a runtime PM reference on the supplier device.  Accordingly, make
      rpm_suspend() (for the consumer) and pm_runtime_clean_up_links()
      decrement it and drop runtime PM references to the supplier
      device in a loop until rpm_active becones 1 again.
      
      Fixes: ead18c23 ("driver core: Introduce device links reference counting")
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      d5495331
    • Rafael J. Wysocki's avatar
      driver core: Do not resume suppliers under device_links_write_lock() · 838a43ff
      Rafael J. Wysocki authored
      
      stable inclusion
      from linux-4.19.99
      commit 301c669961142183a7b157cc79bbba3d963b8a29
      
      --------------------------------
      
      [ Upstream commit 5db25c9e ]
      
      It is incorrect to call pm_runtime_get_sync() under
      device_links_write_lock(), because it may end up trying to take
      device_links_read_lock() while resuming the target device and that
      will deadlock in the non-SRCU case, so avoid that by resuming the
      supplier device in device_link_add() before calling
      device_links_write_lock().
      
      Fixes: 21d5c57b ("PM / runtime: Use device links")
      Fixes: baa8809f ("PM / runtime: Optimize the use of device links")
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
      838a43ff