From b10f91e44ffde82817657febf58fa52b9c0b0b22 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 30 Mar 2022 11:15:05 +0200 Subject: [PATCH] 5.17-stable patches added patches: iommu-iova-improve-32-bit-free-space-estimate.patch --- ...a-improve-32-bit-free-space-estimate.patch | 52 +++++++++++++++++++ queue-5.17/series | 1 + 2 files changed, 53 insertions(+) create mode 100644 queue-5.17/iommu-iova-improve-32-bit-free-space-estimate.patch diff --git a/queue-5.17/iommu-iova-improve-32-bit-free-space-estimate.patch b/queue-5.17/iommu-iova-improve-32-bit-free-space-estimate.patch new file mode 100644 index 00000000000..7e117896ae6 --- /dev/null +++ b/queue-5.17/iommu-iova-improve-32-bit-free-space-estimate.patch @@ -0,0 +1,52 @@ +From 5b61343b50590fb04a3f6be2cdc4868091757262 Mon Sep 17 00:00:00 2001 +From: Robin Murphy +Date: Thu, 3 Mar 2022 14:40:08 +0000 +Subject: iommu/iova: Improve 32-bit free space estimate + +From: Robin Murphy + +commit 5b61343b50590fb04a3f6be2cdc4868091757262 upstream. + +For various reasons based on the allocator behaviour and typical +use-cases at the time, when the max32_alloc_size optimisation was +introduced it seemed reasonable to couple the reset of the tracked +size to the update of cached32_node upon freeing a relevant IOVA. +However, since subsequent optimisations focused on helping genuine +32-bit devices make best use of even more limited address spaces, it +is now a lot more likely for cached32_node to be anywhere in a "full" +32-bit address space, and as such more likely for space to become +available from IOVAs below that node being freed. + +At this point, the short-cut in __cached_rbnode_delete_update() really +doesn't hold up any more, and we need to fix the logic to reliably +provide the expected behaviour. We still want cached32_node to only move +upwards, but we should reset the allocation size if *any* 32-bit space +has become available. + +Reported-by: Yunfei Wang +Signed-off-by: Robin Murphy +Reviewed-by: Miles Chen +Link: https://lore.kernel.org/r/033815732d83ca73b13c11485ac39336f15c3b40.1646318408.git.robin.murphy@arm.com +Signed-off-by: Joerg Roedel +Cc: Miles Chen +Signed-off-by: Greg Kroah-Hartman +--- + drivers/iommu/iova.c | 5 +++-- + 1 file changed, 3 insertions(+), 2 deletions(-) + +--- a/drivers/iommu/iova.c ++++ b/drivers/iommu/iova.c +@@ -95,10 +95,11 @@ __cached_rbnode_delete_update(struct iov + cached_iova = to_iova(iovad->cached32_node); + if (free == cached_iova || + (free->pfn_hi < iovad->dma_32bit_pfn && +- free->pfn_lo >= cached_iova->pfn_lo)) { ++ free->pfn_lo >= cached_iova->pfn_lo)) + iovad->cached32_node = rb_next(&free->node); ++ ++ if (free->pfn_lo < iovad->dma_32bit_pfn) + iovad->max32_alloc_size = iovad->dma_32bit_pfn; +- } + + cached_iova = to_iova(iovad->cached_node); + if (free->pfn_lo >= cached_iova->pfn_lo) diff --git a/queue-5.17/series b/queue-5.17/series index 1af68a5608f..1c965170b05 100644 --- a/queue-5.17/series +++ b/queue-5.17/series @@ -7,3 +7,4 @@ mm-kfence-fix-missing-objcg-housekeeping-for-slab.patch locking-lockdep-avoid-potential-access-of-invalid-memory-in-lock_class.patch drm-amdgpu-move-px-checking-into-amdgpu_device_ip_early_init.patch drm-amdgpu-only-check-for-_pr3-on-dgpus.patch +iommu-iova-improve-32-bit-free-space-estimate.patch -- 2.47.3