iommu/amd: Fix IOMMU perf counter clobbering during init
authorShuah Khan <skhan@linuxfoundation.org>
Thu, 23 Jan 2020 22:32:14 +0000 (15:32 -0700)
committerJoerg Roedel <jroedel@suse.de>
Fri, 24 Jan 2020 14:28:40 +0000 (15:28 +0100)
commit8c17bbf6c8f70058a66305f2e1982552e6ea7f47
tree8d9f6685bd20bd711f9f61cb6d892cac47bdd38e
parentbf708cfb2f4811d1948a88c41ab96587e84ad344
iommu/amd: Fix IOMMU perf counter clobbering during init

init_iommu_perf_ctr() clobbers the register when it checks write access
to IOMMU perf counters and fails to restore when they are writable.

Add save and restore to fix it.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Fixes: 30861ddc9cca4 ("perf/x86/amd: Add IOMMU Performance Counter resource management")
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
drivers/iommu/amd_iommu_init.c