The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025050556-copier-vengeful-2f43@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 32dce6b1949a696dc7abddc04de8cbe35c260217 Mon Sep 17 00:00:00 2001
From: Janne Grunau <j(a)jannau.net>
Date: Tue, 4 Mar 2025 20:12:14 +0100
Subject: [PATCH] drm: Select DRM_KMS_HELPER from
DRM_DEBUG_DP_MST_TOPOLOGY_REFS
Using "depends on" and "select" for the same Kconfig symbol is known to
cause circular dependencies (cmp. "Kconfig recursive dependency
limitations" in Documentation/kbuild/kconfig-language.rst.
DRM drivers are selecting drm helpers so do the same for
DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
Fixes following circular dependency reported on x86 for the downstream
Asahi Linux tree:
error: recursive dependency detected!
symbol DRM_KMS_HELPER is selected by DRM_GEM_SHMEM_HELPER
symbol DRM_GEM_SHMEM_HELPER is selected by RUST_DRM_GEM_SHMEM_HELPER
symbol RUST_DRM_GEM_SHMEM_HELPER is selected by DRM_ASAHI
symbol DRM_ASAHI depends on RUST
symbol RUST depends on CALL_PADDING
symbol CALL_PADDING depends on OBJTOOL
symbol OBJTOOL is selected by STACK_VALIDATION
symbol STACK_VALIDATION depends on UNWINDER_FRAME_POINTER
symbol UNWINDER_FRAME_POINTER is part of choice block at arch/x86/Kconfig.debug:224
symbol <choice> unknown is visible depending on UNWINDER_GUESS
symbol UNWINDER_GUESS prompt is visible depending on STACKDEPOT
symbol STACKDEPOT is selected by DRM_DEBUG_DP_MST_TOPOLOGY_REFS
symbol DRM_DEBUG_DP_MST_TOPOLOGY_REFS depends on DRM_KMS_HELPER
Fixes: 12a280c72868 ("drm/dp_mst: Add topology ref history tracking for debugging")
Cc: stable(a)vger.kernel.org
Signed-off-by: Janne Grunau <j(a)jannau.net>
Acked-by: Thomas Zimmermann <tzimmermann(a)suse.de>
Link: https://lore.kernel.org/r/20250304-drm_debug_dp_mst_topo_kconfig-v1-1-e16fd…
Signed-off-by: Alyssa Rosenzweig <alyssa(a)rosenzweig.io>
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2cba2b6ebe1c..f01925ed8176 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -188,7 +188,7 @@ config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
bool "Enable refcount backtrace history in the DP MST helpers"
depends on STACKTRACE_SUPPORT
select STACKDEPOT
- depends on DRM_KMS_HELPER
+ select DRM_KMS_HELPER
depends on DEBUG_KERNEL
depends on EXPERT
help
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025050556-precision-sandbank-dcf8@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 32dce6b1949a696dc7abddc04de8cbe35c260217 Mon Sep 17 00:00:00 2001
From: Janne Grunau <j(a)jannau.net>
Date: Tue, 4 Mar 2025 20:12:14 +0100
Subject: [PATCH] drm: Select DRM_KMS_HELPER from
DRM_DEBUG_DP_MST_TOPOLOGY_REFS
Using "depends on" and "select" for the same Kconfig symbol is known to
cause circular dependencies (cmp. "Kconfig recursive dependency
limitations" in Documentation/kbuild/kconfig-language.rst.
DRM drivers are selecting drm helpers so do the same for
DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
Fixes following circular dependency reported on x86 for the downstream
Asahi Linux tree:
error: recursive dependency detected!
symbol DRM_KMS_HELPER is selected by DRM_GEM_SHMEM_HELPER
symbol DRM_GEM_SHMEM_HELPER is selected by RUST_DRM_GEM_SHMEM_HELPER
symbol RUST_DRM_GEM_SHMEM_HELPER is selected by DRM_ASAHI
symbol DRM_ASAHI depends on RUST
symbol RUST depends on CALL_PADDING
symbol CALL_PADDING depends on OBJTOOL
symbol OBJTOOL is selected by STACK_VALIDATION
symbol STACK_VALIDATION depends on UNWINDER_FRAME_POINTER
symbol UNWINDER_FRAME_POINTER is part of choice block at arch/x86/Kconfig.debug:224
symbol <choice> unknown is visible depending on UNWINDER_GUESS
symbol UNWINDER_GUESS prompt is visible depending on STACKDEPOT
symbol STACKDEPOT is selected by DRM_DEBUG_DP_MST_TOPOLOGY_REFS
symbol DRM_DEBUG_DP_MST_TOPOLOGY_REFS depends on DRM_KMS_HELPER
Fixes: 12a280c72868 ("drm/dp_mst: Add topology ref history tracking for debugging")
Cc: stable(a)vger.kernel.org
Signed-off-by: Janne Grunau <j(a)jannau.net>
Acked-by: Thomas Zimmermann <tzimmermann(a)suse.de>
Link: https://lore.kernel.org/r/20250304-drm_debug_dp_mst_topo_kconfig-v1-1-e16fd…
Signed-off-by: Alyssa Rosenzweig <alyssa(a)rosenzweig.io>
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2cba2b6ebe1c..f01925ed8176 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -188,7 +188,7 @@ config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
bool "Enable refcount backtrace history in the DP MST helpers"
depends on STACKTRACE_SUPPORT
select STACKDEPOT
- depends on DRM_KMS_HELPER
+ select DRM_KMS_HELPER
depends on DEBUG_KERNEL
depends on EXPERT
help
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 32dce6b1949a696dc7abddc04de8cbe35c260217
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025050555-pulse-ended-2cea@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 32dce6b1949a696dc7abddc04de8cbe35c260217 Mon Sep 17 00:00:00 2001
From: Janne Grunau <j(a)jannau.net>
Date: Tue, 4 Mar 2025 20:12:14 +0100
Subject: [PATCH] drm: Select DRM_KMS_HELPER from
DRM_DEBUG_DP_MST_TOPOLOGY_REFS
Using "depends on" and "select" for the same Kconfig symbol is known to
cause circular dependencies (cmp. "Kconfig recursive dependency
limitations" in Documentation/kbuild/kconfig-language.rst.
DRM drivers are selecting drm helpers so do the same for
DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
Fixes following circular dependency reported on x86 for the downstream
Asahi Linux tree:
error: recursive dependency detected!
symbol DRM_KMS_HELPER is selected by DRM_GEM_SHMEM_HELPER
symbol DRM_GEM_SHMEM_HELPER is selected by RUST_DRM_GEM_SHMEM_HELPER
symbol RUST_DRM_GEM_SHMEM_HELPER is selected by DRM_ASAHI
symbol DRM_ASAHI depends on RUST
symbol RUST depends on CALL_PADDING
symbol CALL_PADDING depends on OBJTOOL
symbol OBJTOOL is selected by STACK_VALIDATION
symbol STACK_VALIDATION depends on UNWINDER_FRAME_POINTER
symbol UNWINDER_FRAME_POINTER is part of choice block at arch/x86/Kconfig.debug:224
symbol <choice> unknown is visible depending on UNWINDER_GUESS
symbol UNWINDER_GUESS prompt is visible depending on STACKDEPOT
symbol STACKDEPOT is selected by DRM_DEBUG_DP_MST_TOPOLOGY_REFS
symbol DRM_DEBUG_DP_MST_TOPOLOGY_REFS depends on DRM_KMS_HELPER
Fixes: 12a280c72868 ("drm/dp_mst: Add topology ref history tracking for debugging")
Cc: stable(a)vger.kernel.org
Signed-off-by: Janne Grunau <j(a)jannau.net>
Acked-by: Thomas Zimmermann <tzimmermann(a)suse.de>
Link: https://lore.kernel.org/r/20250304-drm_debug_dp_mst_topo_kconfig-v1-1-e16fd…
Signed-off-by: Alyssa Rosenzweig <alyssa(a)rosenzweig.io>
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2cba2b6ebe1c..f01925ed8176 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -188,7 +188,7 @@ config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
bool "Enable refcount backtrace history in the DP MST helpers"
depends on STACKTRACE_SUPPORT
select STACKDEPOT
- depends on DRM_KMS_HELPER
+ select DRM_KMS_HELPER
depends on DEBUG_KERNEL
depends on EXPERT
help
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 12f78021973ae422564b234136c702a305932d73
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025050545-renovator-scuba-7cbb@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 12f78021973ae422564b234136c702a305932d73 Mon Sep 17 00:00:00 2001
From: Balbir Singh <balbirs(a)nvidia.com>
Date: Sat, 12 Apr 2025 10:23:54 +1000
Subject: [PATCH] iommu/arm-smmu-v3: Fix pgsize_bit for sva domains
UBSan caught a bug with IOMMU SVA domains, where the reported exponent
value in __arm_smmu_tlb_inv_range() was >= 64.
__arm_smmu_tlb_inv_range() uses the domain's pgsize_bitmap to compute
the number of pages to invalidate and the invalidation range. Currently
arm_smmu_sva_domain_alloc() does not setup the iommu domain's
pgsize_bitmap. This leads to __ffs() on the value returning 64 and that
leads to undefined behaviour w.r.t. shift operations
Fix this by initializing the iommu_domain's pgsize_bitmap to PAGE_SIZE.
Effectively the code needs to use the smallest page size for
invalidation
Cc: stable(a)vger.kernel.org
Fixes: eb6c97647be2 ("iommu/arm-smmu-v3: Avoid constructing invalid range commands")
Suggested-by: Jason Gunthorpe <jgg(a)nvidia.com>
Signed-off-by: Balbir Singh <balbirs(a)nvidia.com>
Cc: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
Cc: Will Deacon <will(a)kernel.org>
Cc: Robin Murphy <robin.murphy(a)arm.com>
Cc: Joerg Roedel <joro(a)8bytes.org>
Cc: Jason Gunthorpe <jgg(a)ziepe.ca>
Reviewed-by: Jason Gunthorpe <jgg(a)nvidia.com>
Link: https://lore.kernel.org/r/20250412002354.3071449-1-balbirs@nvidia.com
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 9ba596430e7c..980cc6b33c43 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -411,6 +411,12 @@ struct iommu_domain *arm_smmu_sva_domain_alloc(struct device *dev,
return ERR_CAST(smmu_domain);
smmu_domain->domain.type = IOMMU_DOMAIN_SVA;
smmu_domain->domain.ops = &arm_smmu_sva_domain_ops;
+
+ /*
+ * Choose page_size as the leaf page size for invalidation when
+ * ARM_SMMU_FEAT_RANGE_INV is present
+ */
+ smmu_domain->domain.pgsize_bitmap = PAGE_SIZE;
smmu_domain->smmu = smmu;
ret = xa_alloc(&arm_smmu_asid_xa, &asid, smmu_domain,
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 12f78021973ae422564b234136c702a305932d73
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025050545-next-pesticide-ba2f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 12f78021973ae422564b234136c702a305932d73 Mon Sep 17 00:00:00 2001
From: Balbir Singh <balbirs(a)nvidia.com>
Date: Sat, 12 Apr 2025 10:23:54 +1000
Subject: [PATCH] iommu/arm-smmu-v3: Fix pgsize_bit for sva domains
UBSan caught a bug with IOMMU SVA domains, where the reported exponent
value in __arm_smmu_tlb_inv_range() was >= 64.
__arm_smmu_tlb_inv_range() uses the domain's pgsize_bitmap to compute
the number of pages to invalidate and the invalidation range. Currently
arm_smmu_sva_domain_alloc() does not setup the iommu domain's
pgsize_bitmap. This leads to __ffs() on the value returning 64 and that
leads to undefined behaviour w.r.t. shift operations
Fix this by initializing the iommu_domain's pgsize_bitmap to PAGE_SIZE.
Effectively the code needs to use the smallest page size for
invalidation
Cc: stable(a)vger.kernel.org
Fixes: eb6c97647be2 ("iommu/arm-smmu-v3: Avoid constructing invalid range commands")
Suggested-by: Jason Gunthorpe <jgg(a)nvidia.com>
Signed-off-by: Balbir Singh <balbirs(a)nvidia.com>
Cc: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
Cc: Will Deacon <will(a)kernel.org>
Cc: Robin Murphy <robin.murphy(a)arm.com>
Cc: Joerg Roedel <joro(a)8bytes.org>
Cc: Jason Gunthorpe <jgg(a)ziepe.ca>
Reviewed-by: Jason Gunthorpe <jgg(a)nvidia.com>
Link: https://lore.kernel.org/r/20250412002354.3071449-1-balbirs@nvidia.com
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 9ba596430e7c..980cc6b33c43 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -411,6 +411,12 @@ struct iommu_domain *arm_smmu_sva_domain_alloc(struct device *dev,
return ERR_CAST(smmu_domain);
smmu_domain->domain.type = IOMMU_DOMAIN_SVA;
smmu_domain->domain.ops = &arm_smmu_sva_domain_ops;
+
+ /*
+ * Choose page_size as the leaf page size for invalidation when
+ * ARM_SMMU_FEAT_RANGE_INV is present
+ */
+ smmu_domain->domain.pgsize_bitmap = PAGE_SIZE;
smmu_domain->smmu = smmu;
ret = xa_alloc(&arm_smmu_asid_xa, &asid, smmu_domain,
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 12f78021973ae422564b234136c702a305932d73
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025050539-scorpion-gents-a5e3@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 12f78021973ae422564b234136c702a305932d73 Mon Sep 17 00:00:00 2001
From: Balbir Singh <balbirs(a)nvidia.com>
Date: Sat, 12 Apr 2025 10:23:54 +1000
Subject: [PATCH] iommu/arm-smmu-v3: Fix pgsize_bit for sva domains
UBSan caught a bug with IOMMU SVA domains, where the reported exponent
value in __arm_smmu_tlb_inv_range() was >= 64.
__arm_smmu_tlb_inv_range() uses the domain's pgsize_bitmap to compute
the number of pages to invalidate and the invalidation range. Currently
arm_smmu_sva_domain_alloc() does not setup the iommu domain's
pgsize_bitmap. This leads to __ffs() on the value returning 64 and that
leads to undefined behaviour w.r.t. shift operations
Fix this by initializing the iommu_domain's pgsize_bitmap to PAGE_SIZE.
Effectively the code needs to use the smallest page size for
invalidation
Cc: stable(a)vger.kernel.org
Fixes: eb6c97647be2 ("iommu/arm-smmu-v3: Avoid constructing invalid range commands")
Suggested-by: Jason Gunthorpe <jgg(a)nvidia.com>
Signed-off-by: Balbir Singh <balbirs(a)nvidia.com>
Cc: Jean-Philippe Brucker <jean-philippe(a)linaro.org>
Cc: Will Deacon <will(a)kernel.org>
Cc: Robin Murphy <robin.murphy(a)arm.com>
Cc: Joerg Roedel <joro(a)8bytes.org>
Cc: Jason Gunthorpe <jgg(a)ziepe.ca>
Reviewed-by: Jason Gunthorpe <jgg(a)nvidia.com>
Link: https://lore.kernel.org/r/20250412002354.3071449-1-balbirs@nvidia.com
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 9ba596430e7c..980cc6b33c43 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -411,6 +411,12 @@ struct iommu_domain *arm_smmu_sva_domain_alloc(struct device *dev,
return ERR_CAST(smmu_domain);
smmu_domain->domain.type = IOMMU_DOMAIN_SVA;
smmu_domain->domain.ops = &arm_smmu_sva_domain_ops;
+
+ /*
+ * Choose page_size as the leaf page size for invalidation when
+ * ARM_SMMU_FEAT_RANGE_INV is present
+ */
+ smmu_domain->domain.pgsize_bitmap = PAGE_SIZE;
smmu_domain->smmu = smmu;
ret = xa_alloc(&arm_smmu_asid_xa, &asid, smmu_domain,
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x b00d24997a11c10d3e420614f0873b83ce358a34
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025050523-phonics-bankable-dd5b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b00d24997a11c10d3e420614f0873b83ce358a34 Mon Sep 17 00:00:00 2001
From: Nicolin Chen <nicolinc(a)nvidia.com>
Date: Tue, 15 Apr 2025 11:56:20 -0700
Subject: [PATCH] iommu/arm-smmu-v3: Fix iommu_device_probe bug due to
duplicated stream ids
ASPEED VGA card has two built-in devices:
0008:06:00.0 PCI bridge: ASPEED Technology, Inc. AST1150 PCI-to-PCI Bridge (rev 06)
0008:07:00.0 VGA compatible controller: ASPEED Technology, Inc. ASPEED Graphics Family (rev 52)
Its toplogy looks like this:
+-[0008:00]---00.0-[01-09]--+-00.0-[02-09]--+-00.0-[03]----00.0 Sandisk Corp Device 5017
| +-01.0-[04]--
| +-02.0-[05]----00.0 NVIDIA Corporation Device
| +-03.0-[06-07]----00.0-[07]----00.0 ASPEED Technology, Inc. ASPEED Graphics Family
| +-04.0-[08]----00.0 Renesas Technology Corp. uPD720201 USB 3.0 Host Controller
| \-05.0-[09]----00.0 Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
\-00.1 PMC-Sierra Inc. Device 4028
The IORT logic populaties two identical IDs into the fwspec->ids array via
DMA aliasing in iort_pci_iommu_init() called by pci_for_each_dma_alias().
Though the SMMU driver had been able to handle this situation since commit
563b5cbe334e ("iommu/arm-smmu-v3: Cope with duplicated Stream IDs"), that
got broken by the later commit cdf315f907d4 ("iommu/arm-smmu-v3: Maintain
a SID->device structure"), which ended up with allocating separate streams
with the same stuffing.
On a kernel prior to v6.15-rc1, there has been an overlooked warning:
pci 0008:07:00.0: vgaarb: setting as boot VGA device
pci 0008:07:00.0: vgaarb: bridge control possible
pci 0008:07:00.0: vgaarb: VGA device added: decodes=io+mem,owns=none,locks=none
pcieport 0008:06:00.0: Adding to iommu group 14
ast 0008:07:00.0: stream 67328 already in tree <===== WARNING
ast 0008:07:00.0: enabling device (0002 -> 0003)
ast 0008:07:00.0: Using default configuration
ast 0008:07:00.0: AST 2600 detected
ast 0008:07:00.0: [drm] Using analog VGA
ast 0008:07:00.0: [drm] dram MCLK=396 Mhz type=1 bus_width=16
[drm] Initialized ast 0.1.0 for 0008:07:00.0 on minor 0
ast 0008:07:00.0: [drm] fb0: astdrmfb frame buffer device
With v6.15-rc, since the commit bcb81ac6ae3c ("iommu: Get DT/ACPI parsing
into the proper probe path"), the error returned with the warning is moved
to the SMMU device probe flow:
arm_smmu_probe_device+0x15c/0x4c0
__iommu_probe_device+0x150/0x4f8
probe_iommu_group+0x44/0x80
bus_for_each_dev+0x7c/0x100
bus_iommu_probe+0x48/0x1a8
iommu_device_register+0xb8/0x178
arm_smmu_device_probe+0x1350/0x1db0
which then fails the entire SMMU driver probe:
pci 0008:06:00.0: Adding to iommu group 21
pci 0008:07:00.0: stream 67328 already in tree
arm-smmu-v3 arm-smmu-v3.9.auto: Failed to register iommu
arm-smmu-v3 arm-smmu-v3.9.auto: probe with driver arm-smmu-v3 failed with error -22
Since SMMU driver had been already expecting a potential duplicated Stream
ID in arm_smmu_install_ste_for_dev(), change the arm_smmu_insert_master()
routine to ignore a duplicated ID from the fwspec->sids array as well.
Note: this has been failing the iommu_device_probe() since 2021, although a
recent iommu commit in v6.15-rc1 that moves iommu_device_probe() started to
fail the SMMU driver probe. Since nobody has cared about DMA Alias support,
leave that as it was but fix the fundamental iommu_device_probe() breakage.
Fixes: cdf315f907d4 ("iommu/arm-smmu-v3: Maintain a SID->device structure")
Cc: stable(a)vger.kernel.org
Suggested-by: Jason Gunthorpe <jgg(a)nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg(a)nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc(a)nvidia.com>
Link: https://lore.kernel.org/r/20250415185620.504299-1-nicolinc@nvidia.com
Signed-off-by: Will Deacon <will(a)kernel.org>
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 5467f85dd463..0826b6bdf327 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3388,6 +3388,7 @@ static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
mutex_lock(&smmu->streams_mutex);
for (i = 0; i < fwspec->num_ids; i++) {
struct arm_smmu_stream *new_stream = &master->streams[i];
+ struct rb_node *existing;
u32 sid = fwspec->ids[i];
new_stream->id = sid;
@@ -3398,10 +3399,20 @@ static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
break;
/* Insert into SID tree */
- if (rb_find_add(&new_stream->node, &smmu->streams,
- arm_smmu_streams_cmp_node)) {
- dev_warn(master->dev, "stream %u already in tree\n",
- sid);
+ existing = rb_find_add(&new_stream->node, &smmu->streams,
+ arm_smmu_streams_cmp_node);
+ if (existing) {
+ struct arm_smmu_master *existing_master =
+ rb_entry(existing, struct arm_smmu_stream, node)
+ ->master;
+
+ /* Bridged PCI devices may end up with duplicated IDs */
+ if (existing_master == master)
+ continue;
+
+ dev_warn(master->dev,
+ "stream %u already in tree from dev %s\n", sid,
+ dev_name(existing_master->dev));
ret = -EINVAL;
break;
}