crypto: x86/crc32c-intel - Don't match some Zhaoxin CPUs
zhaoxin inclusion category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=19 CVE: NA ---------------------------------------------------------------- The driver crc32c-intel match CPUs supporting X86_FEATURE_XMM4_2. On platforms with Zhaoxin CPUs supporting this X86 feature, when crc32c-intel and crc32c-generic are both registered, system will use crc32c-intel because its .cra_priority is greater than crc32c-generic. When doing lmbench3 Create and Delete file test on partitions with ext4 enabling metadata checksum, found using crc32c-generic driver could get about 20% performance gain than using the driver crc32c-intel on some Zhaoxin CPUs. This case expect to use crc32c-generic driver for these Zhaoxin CPUs to get performance gain, so remove these Zhaoxin CPUs support from crc32c-intel. This patch was submitted to mainline kernel but not accepted by upstream maintainer whose reason is "Then create a BUG flag for it,". We think this is not a CPU bug for Zhaoxin CPUs. So should patch the crc32c driver for Zhaoxin CPUs but not report a BUG. References: https://lkml.org/lkml/2020/12/11/308 Signed-off-by:LeoLiu-oc <LeoLiu-oc@zhaoxin.com> Reviewed-by:
Hanjun Guo <guohanjun@huawei.com> Reviewed-by:
LeoLiu-oc <LeoLiu-oc@zhaoxin.com> Signed-off-by:
Cheng Jian <cj.chengjian@huawei.com>
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