Jacob Pan 7cfa7abb24 iommu/vt-d: Handle volatile descriptor status read ... [ Upstream commit b5e86a9554 ] Queued invalidation wait descriptor status is volatile in that IOMMU hardware writes the data upon completion. Use READ_ONCE() to prevent compiler optimizations which ensures memory reads every time. As a side effect, READ_ONCE() also enforces strict types and may add an extra instruction. But it should not have negative performance impact since we use cpu_relax anyway and the extra time(by adding an instruction) may allow IOMMU HW request cacheline ownership easier. e.g. gcc 12.3 BEFORE: 81 38 ad de 00 00 cmpl $0x2,(%rax) AFTER (with READ_ONCE()) 772f: 8b 00 mov (%rax),%eax 7731: 3d ad de 00 00 cmp $0x2,%eax //status data is 32 bit Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20240607173817.3914600-1-jacob.jun.pan@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20240702130839.108139-2-baolu.lu@linux.intel.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-09-12 11:11:35 +02:00
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cap_audit.c
cap_audit.h
debugfs.c
dmar.c	iommu/vt-d: Handle volatile descriptor status read	2024-09-12 11:11:35 +02:00
iommu.c	iommu/vt-d: Fix identity map bounds in si_domain_init()	2024-08-03 08:54:03 +02:00
iommu.h
irq_remapping.c
Kconfig
Makefile
pasid.c
pasid.h
perf.c
perf.h
perfmon.c	iommu/vt-d: Fix wrong use of pasid config	2024-04-17 11:19:33 +02:00
perfmon.h
svm.c	iommu/vt-d: Allocate local memory for page request queue	2024-04-17 11:19:33 +02:00
trace.c
trace.h