The arm_smmu_mm_invalidate_range function is designed to be called
by mm core for Shared Virtual Addressing purpose between IOMMU and
CPU MMU. However, the ways of two subsystems defining their "end"
addresses are slightly different. IOMMU defines its "end" address
using the last address of an address range, while mm core defines
that using the following address of an address range:
include/linux/mm_types.h:
unsigned long vm_end;
/* The first byte after our end address ...
This mismatch resulted in an incorrect calculation for size so it
failed to be page-size aligned. Further, it caused a dead loop at
"while (iova < end)" check in __arm_smmu_tlb_inv_range function.
This patch fixes the issue by doing the calculation correctly.
Fixes: 2f7e8c553e98d ("iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops")
Cc: [email protected]
Signed-off-by: Nicolin Chen <[email protected]>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
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 22ddd05bbdcd..c623dae1e115 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
@@ -183,7 +183,14 @@ static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
{
struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
struct arm_smmu_domain *smmu_domain = smmu_mn->domain;
- size_t size = end - start + 1;
+ size_t size;
+
+ /*
+ * The mm_types defines vm_end as the first byte after the end address,
+ * different from IOMMU subsystem using the last address of an address
+ * range. So do a simple translation here by calculating size correctly.
+ */
+ size = end - start;
if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_BTM))
arm_smmu_tlb_inv_range_asid(start, size, smmu_mn->cd->asid,
--
2.17.1
On Tue, Apr 19, 2022 at 02:01:58PM -0700, Nicolin Chen wrote:
> The arm_smmu_mm_invalidate_range function is designed to be called
> by mm core for Shared Virtual Addressing purpose between IOMMU and
> CPU MMU. However, the ways of two subsystems defining their "end"
> addresses are slightly different. IOMMU defines its "end" address
> using the last address of an address range, while mm core defines
> that using the following address of an address range:
>
> include/linux/mm_types.h:
> unsigned long vm_end;
> /* The first byte after our end address ...
>
> This mismatch resulted in an incorrect calculation for size so it
> failed to be page-size aligned. Further, it caused a dead loop at
> "while (iova < end)" check in __arm_smmu_tlb_inv_range function.
>
> This patch fixes the issue by doing the calculation correctly.
>
> Fixes: 2f7e8c553e98d ("iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops")
> Cc: [email protected]
> Signed-off-by: Nicolin Chen <[email protected]>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
Reviewed-by: Jason Gunthorpe <[email protected]>
> - size_t size = end - start + 1;
> + size_t size;
> +
> + /*
> + * The mm_types defines vm_end as the first byte after the end address,
> + * different from IOMMU subsystem using the last address of an address
> + * range. So do a simple translation here by calculating size correctly.
> + */
> + size = end - start;
I would skip the comment though
Jason
On Tue, Apr 19, 2022 at 08:10:34PM -0300, Jason Gunthorpe wrote:
> > - size_t size = end - start + 1;
> > + size_t size;
> > +
> > + /*
> > + * The mm_types defines vm_end as the first byte after the end address,
> > + * different from IOMMU subsystem using the last address of an address
> > + * range. So do a simple translation here by calculating size correctly.
> > + */
> > + size = end - start;
>
> I would skip the comment though
It's a bit of highlight here to help us remember in the future,
per Robin's comments at my previous patch.
Thanks!
Nic
On Tue, 19 Apr 2022 14:01:58 -0700, Nicolin Chen wrote:
> The arm_smmu_mm_invalidate_range function is designed to be called
> by mm core for Shared Virtual Addressing purpose between IOMMU and
> CPU MMU. However, the ways of two subsystems defining their "end"
> addresses are slightly different. IOMMU defines its "end" address
> using the last address of an address range, while mm core defines
> that using the following address of an address range:
>
> [...]
Applied to will (for-joerg/arm-smmu/fixes), thanks!
[1/1] iommu/arm-smmu-v3: Fix size calculation in arm_smmu_mm_invalidate_range()
https://git.kernel.org/will/c/95d4782c34a6
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
On Tue, Apr 19, 2022 at 02:01:58PM -0700, Nicolin Chen wrote:
> The arm_smmu_mm_invalidate_range function is designed to be called
> by mm core for Shared Virtual Addressing purpose between IOMMU and
> CPU MMU. However, the ways of two subsystems defining their "end"
> addresses are slightly different. IOMMU defines its "end" address
> using the last address of an address range, while mm core defines
> that using the following address of an address range:
>
> include/linux/mm_types.h:
> unsigned long vm_end;
> /* The first byte after our end address ...
>
> This mismatch resulted in an incorrect calculation for size so it
> failed to be page-size aligned. Further, it caused a dead loop at
> "while (iova < end)" check in __arm_smmu_tlb_inv_range function.
>
> This patch fixes the issue by doing the calculation correctly.
>
> Fixes: 2f7e8c553e98d ("iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops")
> Cc: [email protected]
> Signed-off-by: Nicolin Chen <[email protected]>
Thanks for the fix, I guess we didn't catch this earlier because our test
platforms didn't support range invalidation, so __arm_smmu_tlb_inv_range()
would always use PAGE_SIZE as increment.
Reviewed-by: Jean-Philippe Brucker <[email protected]>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> 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 22ddd05bbdcd..c623dae1e115 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
> @@ -183,7 +183,14 @@ static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
> {
> struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
> struct arm_smmu_domain *smmu_domain = smmu_mn->domain;
> - size_t size = end - start + 1;
> + size_t size;
> +
> + /*
> + * The mm_types defines vm_end as the first byte after the end address,
> + * different from IOMMU subsystem using the last address of an address
> + * range. So do a simple translation here by calculating size correctly.
> + */
> + size = end - start;
>
> if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_BTM))
> arm_smmu_tlb_inv_range_asid(start, size, smmu_mn->cd->asid,
> --
> 2.17.1
>
On 2022-04-19 22:01, Nicolin Chen wrote:
> The arm_smmu_mm_invalidate_range function is designed to be called
> by mm core for Shared Virtual Addressing purpose between IOMMU and
> CPU MMU. However, the ways of two subsystems defining their "end"
> addresses are slightly different. IOMMU defines its "end" address
> using the last address of an address range, while mm core defines
> that using the following address of an address range:
>
> include/linux/mm_types.h:
> unsigned long vm_end;
> /* The first byte after our end address ...
>
> This mismatch resulted in an incorrect calculation for size so it
> failed to be page-size aligned. Further, it caused a dead loop at
> "while (iova < end)" check in __arm_smmu_tlb_inv_range function.
>
> This patch fixes the issue by doing the calculation correctly.
Reviewed-by: Robin Murphy <[email protected]>
> Fixes: 2f7e8c553e98d ("iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops")
> Cc: [email protected]
> Signed-off-by: Nicolin Chen <[email protected]>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> 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 22ddd05bbdcd..c623dae1e115 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
> @@ -183,7 +183,14 @@ static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
> {
> struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
> struct arm_smmu_domain *smmu_domain = smmu_mn->domain;
> - size_t size = end - start + 1;
> + size_t size;
> +
> + /*
> + * The mm_types defines vm_end as the first byte after the end address,
> + * different from IOMMU subsystem using the last address of an address
> + * range. So do a simple translation here by calculating size correctly.
> + */
> + size = end - start;
>
> if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_BTM))
> arm_smmu_tlb_inv_range_asid(start, size, smmu_mn->cd->asid,