5.17-stable patches

added patches:
	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 (file)
index 0000000..7e11789
--- /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 <robin.murphy@arm.com>
+Date: Thu, 3 Mar 2022 14:40:08 +0000
+Subject: iommu/iova: Improve 32-bit free space estimate
+
+From: Robin Murphy <robin.murphy@arm.com>
+
+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 <yf.wang@mediatek.com>
+Signed-off-by: Robin Murphy <robin.murphy@arm.com>
+Reviewed-by: Miles Chen <miles.chen@mediatek.com>
+Link: https://lore.kernel.org/r/033815732d83ca73b13c11485ac39336f15c3b40.1646318408.git.robin.murphy@arm.com
+Signed-off-by: Joerg Roedel <jroedel@suse.de>
+Cc: Miles Chen <miles.chen@mediatek.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ 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 1af68a5608fa46b6d91b4a302bde90ffdb92d419..1c965170b053eb0485024e41587a60ff0944627d 100644 (file)
--- 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