[PATCH v11 0/4] io-pgtable-arm + drm/msm: Extend iova fault debugging

[PATCH v11 0/4] io-pgtable-arm + drm/msm: Extend iova fault debugging

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

This series extends io-pgtable-arm with a method to retrieve the page
table entries traversed in the process of address translation, and then
beefs up drm/msm gpu devcore dump to include this (and additional info)
in the devcore dump.

This is a respin of https://patchwork.freedesktop.org/series/94968/
(minus a patch that was already merged)

v2:  Fix an armv7/32b build error in the last patch
v3:  Incorperate Will Deacon's suggestion to make the interface
     callback based.
v4:  Actually wire up the callback
v5:  Drop the callback approach
v6:  Make walk-data struct pgtable specific and rename
     io_pgtable_walk_data to arm_lpae_io_pgtable_walk_data
v7:  Re-use the pgtable walker added for arm_lpae_read_and_clear_dirty()
v8:  Pass pte pointer to callback so it can modify the actual pte
v9:  Fix selftests_running case
v10: Call visit cb for all nodes traversed, leave the decision about
     whether to care about non-leaf nodes to the callback
v11: Adjust logic in 3/4 [smostafa@]

Rob Clark (4):
  iommu/io-pgtable-arm: Make pgtable walker more generic
  iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys
  iommu/io-pgtable-arm: Add way to debug pgtable walk
  drm/msm: Extend gpu devcore dumps with pgtbl info

 drivers/gpu/drm/msm/adreno/adreno_gpu.c |  10 ++
 drivers/gpu/drm/msm/msm_gpu.c           |   9 ++
 drivers/gpu/drm/msm/msm_gpu.h           |   8 ++
 drivers/gpu/drm/msm/msm_iommu.c         |  22 ++++
 drivers/gpu/drm/msm/msm_mmu.h           |   3 +-
 drivers/iommu/io-pgtable-arm.c          | 157 +++++++++++++++---------
 include/linux/io-pgtable.h              |  15 +++
 7 files changed, 167 insertions(+), 57 deletions(-)

-- 
2.47.1

[PATCH v11 1/4] iommu/io-pgtable-arm: Make pgtable walker more generic

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

We can re-use this basic pgtable walk logic in a few places.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
---
 drivers/iommu/io-pgtable-arm.c | 67 ++++++++++++++++++++++------------
 1 file changed, 43 insertions(+), 24 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 0e67f1721a3d..7e9c0f8ae138 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -749,33 +749,33 @@ static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
 }
 
 struct io_pgtable_walk_data {
-	struct iommu_dirty_bitmap	*dirty;
+	struct io_pgtable		*iop;
+	void				*data;
+	int (*visit)(struct io_pgtable_walk_data *walk_data, int lvl,
+		     arm_lpae_iopte *ptep, size_t size);
 	unsigned long			flags;
 	u64				addr;
 	const u64			end;
 };
 
-static int __arm_lpae_iopte_walk_dirty(struct arm_lpae_io_pgtable *data,
-				       struct io_pgtable_walk_data *walk_data,
-				       arm_lpae_iopte *ptep,
-				       int lvl);
+static int __arm_lpae_iopte_walk(struct arm_lpae_io_pgtable *data,
+				 struct io_pgtable_walk_data *walk_data,
+				 arm_lpae_iopte *ptep,
+				 int lvl);
 
-static int io_pgtable_visit_dirty(struct arm_lpae_io_pgtable *data,
-				  struct io_pgtable_walk_data *walk_data,
-				  arm_lpae_iopte *ptep, int lvl)
+static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
+			    struct io_pgtable_walk_data *walk_data,
+			    arm_lpae_iopte *ptep, int lvl)
 {
 	struct io_pgtable *iop = &data->iop;
 	arm_lpae_iopte pte = READ_ONCE(*ptep);
 
-	if (iopte_leaf(pte, lvl, iop->fmt)) {
-		size_t size = ARM_LPAE_BLOCK_SIZE(lvl, data);
+	size_t size = ARM_LPAE_BLOCK_SIZE(lvl, data);
+	int ret = walk_data->visit(walk_data, lvl, ptep, size);
+	if (ret)
+		return ret;
 
-		if (iopte_writeable_dirty(pte)) {
-			iommu_dirty_bitmap_record(walk_data->dirty,
-						  walk_data->addr, size);
-			if (!(walk_data->flags & IOMMU_DIRTY_NO_CLEAR))
-				iopte_set_writeable_clean(ptep);
-		}
+	if (iopte_leaf(pte, lvl, iop->fmt)) {
 		walk_data->addr += size;
 		return 0;
 	}
@@ -784,13 +784,13 @@ static int io_pgtable_visit_dirty(struct arm_lpae_io_pgtable *data,
 		return -EINVAL;
 
 	ptep = iopte_deref(pte, data);
-	return __arm_lpae_iopte_walk_dirty(data, walk_data, ptep, lvl + 1);
+	return __arm_lpae_iopte_walk(data, walk_data, ptep, lvl + 1);
 }
 
-static int __arm_lpae_iopte_walk_dirty(struct arm_lpae_io_pgtable *data,
-				       struct io_pgtable_walk_data *walk_data,
-				       arm_lpae_iopte *ptep,
-				       int lvl)
+static int __arm_lpae_iopte_walk(struct arm_lpae_io_pgtable *data,
+				 struct io_pgtable_walk_data *walk_data,
+				 arm_lpae_iopte *ptep,
+				 int lvl)
 {
 	u32 idx;
 	int max_entries, ret;
@@ -805,7 +805,7 @@ static int __arm_lpae_iopte_walk_dirty(struct arm_lpae_io_pgtable *data,
 
 	for (idx = ARM_LPAE_LVL_IDX(walk_data->addr, lvl, data);
 	     (idx < max_entries) && (walk_data->addr < walk_data->end); ++idx) {
-		ret = io_pgtable_visit_dirty(data, walk_data, ptep + idx, lvl);
+		ret = io_pgtable_visit(data, walk_data, ptep + idx, lvl);
 		if (ret)
 			return ret;
 	}
@@ -813,6 +813,23 @@ static int __arm_lpae_iopte_walk_dirty(struct arm_lpae_io_pgtable *data,
 	return 0;
 }
 
+static int visit_dirty(struct io_pgtable_walk_data *walk_data, int lvl,
+		       arm_lpae_iopte *ptep, size_t size)
+{
+	struct iommu_dirty_bitmap *dirty = walk_data->data;
+
+	if (!iopte_leaf(*ptep, lvl, walk_data->iop->fmt))
+		return 0;
+
+	if (iopte_writeable_dirty(*ptep)) {
+		iommu_dirty_bitmap_record(dirty, walk_data->addr, size);
+		if (!(walk_data->flags & IOMMU_DIRTY_NO_CLEAR))
+			iopte_set_writeable_clean(ptep);
+	}
+
+	return 0;
+}
+
 static int arm_lpae_read_and_clear_dirty(struct io_pgtable_ops *ops,
 					 unsigned long iova, size_t size,
 					 unsigned long flags,
@@ -821,7 +838,9 @@ static int arm_lpae_read_and_clear_dirty(struct io_pgtable_ops *ops,
 	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
 	struct io_pgtable_cfg *cfg = &data->iop.cfg;
 	struct io_pgtable_walk_data walk_data = {
-		.dirty = dirty,
+		.iop = &data->iop,
+		.data = dirty,
+		.visit = visit_dirty,
 		.flags = flags,
 		.addr = iova,
 		.end = iova + size,
@@ -836,7 +855,7 @@ static int arm_lpae_read_and_clear_dirty(struct io_pgtable_ops *ops,
 	if (data->iop.fmt != ARM_64_LPAE_S1)
 		return -EINVAL;
 
-	return __arm_lpae_iopte_walk_dirty(data, &walk_data, ptep, lvl);
+	return __arm_lpae_iopte_walk(data, &walk_data, ptep, lvl);
 }
 
 static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
-- 
2.47.1

[PATCH v11 2/4] iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

Re-use the generic pgtable walk path.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
---
 drivers/iommu/io-pgtable-arm.c | 74 +++++++++++++++++-----------------
 1 file changed, 37 insertions(+), 37 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 7e9c0f8ae138..88b128c77893 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -712,42 +712,6 @@ static size_t arm_lpae_unmap_pages(struct io_pgtable_ops *ops, unsigned long iov
 				data->start_level, ptep);
 }
 
-static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
-					 unsigned long iova)
-{
-	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
-	arm_lpae_iopte pte, *ptep = data->pgd;
-	int lvl = data->start_level;
-
-	do {
-		/* Valid IOPTE pointer? */
-		if (!ptep)
-			return 0;
-
-		/* Grab the IOPTE we're interested in */
-		ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
-		pte = READ_ONCE(*ptep);
-
-		/* Valid entry? */
-		if (!pte)
-			return 0;
-
-		/* Leaf entry? */
-		if (iopte_leaf(pte, lvl, data->iop.fmt))
-			goto found_translation;
-
-		/* Take it to the next level */
-		ptep = iopte_deref(pte, data);
-	} while (++lvl < ARM_LPAE_MAX_LEVELS);
-
-	/* Ran out of page tables to walk */
-	return 0;
-
-found_translation:
-	iova &= (ARM_LPAE_BLOCK_SIZE(lvl, data) - 1);
-	return iopte_to_paddr(pte, data) | iova;
-}
-
 struct io_pgtable_walk_data {
 	struct io_pgtable		*iop;
 	void				*data;
@@ -763,6 +727,41 @@ static int __arm_lpae_iopte_walk(struct arm_lpae_io_pgtable *data,
 				 arm_lpae_iopte *ptep,
 				 int lvl);
 
+struct iova_to_phys_data {
+	arm_lpae_iopte pte;
+	int lvl;
+};
+
+static int visit_iova_to_phys(struct io_pgtable_walk_data *walk_data, int lvl,
+			      arm_lpae_iopte *ptep, size_t size)
+{
+	struct iova_to_phys_data *data = walk_data->data;
+	data->pte = *ptep;
+	data->lvl = lvl;
+	return 0;
+}
+
+static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
+					 unsigned long iova)
+{
+	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+	struct iova_to_phys_data d;
+	struct io_pgtable_walk_data walk_data = {
+		.data = &d,
+		.visit = visit_iova_to_phys,
+		.addr = iova,
+		.end = iova + 1,
+	};
+	int ret;
+
+	ret = __arm_lpae_iopte_walk(data, &walk_data, data->pgd, data->start_level);
+	if (ret)
+		return 0;
+
+	iova &= (ARM_LPAE_BLOCK_SIZE(d.lvl, data) - 1);
+	return iopte_to_paddr(d.pte, data) | iova;
+}
+
 static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
 			    struct io_pgtable_walk_data *walk_data,
 			    arm_lpae_iopte *ptep, int lvl)
@@ -780,8 +779,9 @@ static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
 		return 0;
 	}
 
-	if (WARN_ON(!iopte_table(pte, lvl)))
+	if (!iopte_table(pte, lvl)) {
 		return -EINVAL;
+	}
 
 	ptep = iopte_deref(pte, data);
 	return __arm_lpae_iopte_walk(data, walk_data, ptep, lvl + 1);
-- 
2.47.1

[PATCH v11 3/4] iommu/io-pgtable-arm: Add way to debug pgtable walk

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

Add an io-pgtable method to walk the pgtable returning the raw PTEs that
would be traversed for a given iova access.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/iommu/io-pgtable-arm.c | 26 ++++++++++++++++++++++++++
 include/linux/io-pgtable.h     | 15 +++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 88b128c77893..c51c48851f9f 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -762,6 +762,31 @@ static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
 	return iopte_to_paddr(d.pte, data) | iova;
 }
 
+static int visit_pgtable_walk(struct io_pgtable_walk_data *walk_data, int lvl,
+			      arm_lpae_iopte *ptep, size_t size)
+{
+	struct arm_lpae_io_pgtable_walk_data *data = walk_data->data;
+	data->ptes[lvl] = *ptep;
+	data->level = lvl + 1;
+	return 0;
+}
+
+static int arm_lpae_pgtable_walk(struct io_pgtable_ops *ops, unsigned long iova,
+				 void *wd)
+{
+	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+	struct io_pgtable_walk_data walk_data = {
+		.data = wd,
+		.visit = visit_pgtable_walk,
+		.addr = iova,
+		.end = iova + 1,
+	};
+
+	((struct arm_lpae_io_pgtable_walk_data *)wd)->level = 0;
+
+	return __arm_lpae_iopte_walk(data, &walk_data, data->pgd, data->start_level);
+}
+
 static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
 			    struct io_pgtable_walk_data *walk_data,
 			    arm_lpae_iopte *ptep, int lvl)
@@ -937,6 +962,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
 		.unmap_pages	= arm_lpae_unmap_pages,
 		.iova_to_phys	= arm_lpae_iova_to_phys,
 		.read_and_clear_dirty = arm_lpae_read_and_clear_dirty,
+		.pgtable_walk	= arm_lpae_pgtable_walk,
 	};
 
 	return data;
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index b1ecfc3cd5bc..d7bfbf351975 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -178,12 +178,26 @@ struct io_pgtable_cfg {
 	};
 };
 
+/**
+ * struct arm_lpae_io_pgtable_walk_data - information from a pgtable walk
+ *
+ * @ptes:     The recorded PTE values from the walk
+ * @level:    The level of the last PTE
+ *
+ * @level also specifies the last valid index in @ptes
+ */
+struct arm_lpae_io_pgtable_walk_data {
+	u64 ptes[4];
+	int level;
+};
+
 /**
  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
  *
  * @map_pages:    Map a physically contiguous range of pages of the same size.
  * @unmap_pages:  Unmap a range of virtually contiguous pages of the same size.
  * @iova_to_phys: Translate iova to physical address.
+ * @pgtable_walk: (optional) Perform a page table walk for a given iova.
  *
  * These functions map directly onto the iommu_ops member functions with
  * the same names.
@@ -197,6 +211,7 @@ struct io_pgtable_ops {
 			      struct iommu_iotlb_gather *gather);
 	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
 				    unsigned long iova);
+	int (*pgtable_walk)(struct io_pgtable_ops *ops, unsigned long iova, void *wd);
 	int (*read_and_clear_dirty)(struct io_pgtable_ops *ops,
 				    unsigned long iova, size_t size,
 				    unsigned long flags,
-- 
2.47.1

[PATCH v11 4/4] drm/msm: Extend gpu devcore dumps with pgtbl info

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

In the case of iova fault triggered devcore dumps, include additional
debug information based on what we think is the current page tables,
including the TTBR0 value (which should match what we have in
adreno_smmu_fault_info unless things have gone horribly wrong), and
the pagetable entries traversed in the process of resolving the
faulting iova.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/adreno/adreno_gpu.c | 10 ++++++++++
 drivers/gpu/drm/msm/msm_gpu.c           |  9 +++++++++
 drivers/gpu/drm/msm/msm_gpu.h           |  8 ++++++++
 drivers/gpu/drm/msm/msm_iommu.c         | 22 ++++++++++++++++++++++
 drivers/gpu/drm/msm/msm_mmu.h           |  3 ++-
 5 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 076be0473eb5..f1d6e6665c30 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -868,6 +868,16 @@ void adreno_show(struct msm_gpu *gpu, struct msm_gpu_state *state,
 		drm_printf(p, "  - dir=%s\n", info->flags & IOMMU_FAULT_WRITE ? "WRITE" : "READ");
 		drm_printf(p, "  - type=%s\n", info->type);
 		drm_printf(p, "  - source=%s\n", info->block);
+
+		/* Information extracted from what we think are the current
+		 * pgtables.  Hopefully the TTBR0 matches what we've extracted
+		 * from the SMMU registers in smmu_info!
+		 */
+		drm_puts(p, "pgtable-fault-info:\n");
+		drm_printf(p, "  - ttbr0: %.16llx\n", (u64)info->pgtbl_ttbr0);
+		drm_printf(p, "  - asid: %d\n", info->asid);
+		drm_printf(p, "  - ptes: %.16llx %.16llx %.16llx %.16llx\n",
+			   info->ptes[0], info->ptes[1], info->ptes[2], info->ptes[3]);
 	}
 
 	drm_printf(p, "rbbm-status: 0x%08x\n", state->rbbm_status);
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 0d4a3744cfcb..82f204f3bb8f 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -281,6 +281,15 @@ static void msm_gpu_crashstate_capture(struct msm_gpu *gpu,
 	if (submit) {
 		int i;
 
+		if (state->fault_info.ttbr0) {
+			struct msm_gpu_fault_info *info = &state->fault_info;
+			struct msm_mmu *mmu = submit->aspace->mmu;
+
+			msm_iommu_pagetable_params(mmu, &info->pgtbl_ttbr0,
+						   &info->asid);
+			msm_iommu_pagetable_walk(mmu, info->iova, info->ptes);
+		}
+
 		state->bos = kcalloc(submit->nr_bos,
 			sizeof(struct msm_gpu_state_bo), GFP_KERNEL);
 
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 7cabc8480d7c..e25009150579 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -101,6 +101,14 @@ struct msm_gpu_fault_info {
 	int flags;
 	const char *type;
 	const char *block;
+
+	/* Information about what we think/expect is the current SMMU state,
+	 * for example expected_ttbr0 should match smmu_info.ttbr0 which
+	 * was read back from SMMU registers.
+	 */
+	phys_addr_t pgtbl_ttbr0;
+	u64 ptes[4];
+	int asid;
 };
 
 /**
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 2a94e82316f9..3e692818ba1f 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -195,6 +195,28 @@ struct iommu_domain_geometry *msm_iommu_get_geometry(struct msm_mmu *mmu)
 	return &iommu->domain->geometry;
 }
 
+int
+msm_iommu_pagetable_walk(struct msm_mmu *mmu, unsigned long iova, uint64_t ptes[4])
+{
+	struct msm_iommu_pagetable *pagetable;
+	struct arm_lpae_io_pgtable_walk_data wd = {};
+
+	if (mmu->type != MSM_MMU_IOMMU_PAGETABLE)
+		return -EINVAL;
+
+	pagetable = to_pagetable(mmu);
+
+	if (!pagetable->pgtbl_ops->pgtable_walk)
+		return -EINVAL;
+
+	pagetable->pgtbl_ops->pgtable_walk(pagetable->pgtbl_ops, iova, &wd);
+
+	for (int i = 0; i < ARRAY_SIZE(wd.ptes); i++)
+		ptes[i] = wd.ptes[i];
+
+	return 0;
+}
+
 static const struct msm_mmu_funcs pagetable_funcs = {
 		.map = msm_iommu_pagetable_map,
 		.unmap = msm_iommu_pagetable_unmap,
diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
index 88af4f490881..96e509bd96a6 100644
--- a/drivers/gpu/drm/msm/msm_mmu.h
+++ b/drivers/gpu/drm/msm/msm_mmu.h
@@ -53,7 +53,8 @@ static inline void msm_mmu_set_fault_handler(struct msm_mmu *mmu, void *arg,
 struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent);
 
 int msm_iommu_pagetable_params(struct msm_mmu *mmu, phys_addr_t *ttbr,
-		int *asid);
+			       int *asid);
+int msm_iommu_pagetable_walk(struct msm_mmu *mmu, unsigned long iova, uint64_t ptes[4]);
 struct iommu_domain_geometry *msm_iommu_get_geometry(struct msm_mmu *mmu);
 
 #endif /* __MSM_MMU_H__ */
-- 
2.47.1

Re: [PATCH v11 0/4] io-pgtable-arm + drm/msm: Extend iova fault debugging

[Mostafa Saleh]

Hi Rob,

On Tue, Dec 10, 2024 at 08:51:18AM -0800, Rob Clark wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> This series extends io-pgtable-arm with a method to retrieve the page
> table entries traversed in the process of address translation, and then
> beefs up drm/msm gpu devcore dump to include this (and additional info)
> in the devcore dump.
> 
> This is a respin of https://patchwork.freedesktop.org/series/94968/
> (minus a patch that was already merged)
> 
> v2:  Fix an armv7/32b build error in the last patch
> v3:  Incorperate Will Deacon's suggestion to make the interface
>      callback based.
> v4:  Actually wire up the callback
> v5:  Drop the callback approach
> v6:  Make walk-data struct pgtable specific and rename
>      io_pgtable_walk_data to arm_lpae_io_pgtable_walk_data
> v7:  Re-use the pgtable walker added for arm_lpae_read_and_clear_dirty()
> v8:  Pass pte pointer to callback so it can modify the actual pte
> v9:  Fix selftests_running case
> v10: Call visit cb for all nodes traversed, leave the decision about
>      whether to care about non-leaf nodes to the callback
> v11: Adjust logic in 3/4 [smostafa@]

I see the level initialization was not removed as it was in the diff[1], so it
seems to me that’s redundant as the level is set anyway in the callback, and
actually looking at that I see it’s not used or printed from the driver,
so may it can be removed all together, anyway that’s nit that may be Will can
fix it up while merging.

Otherwise, For the whole series
Reviewed-by: Mostafa Saleh <smostafa@google.com>

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index ed3ba47df350..a884af8fb101 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -731,7 +731,6 @@ static int visit_pgtable_walk(struct io_pgtable_walk_data *walk_data, int lvl,
 {
 	struct arm_lpae_io_pgtable_walk_data *data = walk_data->data;
 	data->ptes[lvl] = *ptep;
-	data->level = lvl + 1;
 	return 0;
 }
 
@@ -746,8 +745,6 @@ static int arm_lpae_pgtable_walk(struct io_pgtable_ops *ops, unsigned long iova,
 		.end = iova + 1,
 	};
 
-	((struct arm_lpae_io_pgtable_walk_data *)wd)->level = 0;
-
 	return __arm_lpae_iopte_walk(data, &walk_data, data->pgd, data->start_level);
 }
 
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 0f17a38a304d..c62e344a4058 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -190,7 +190,6 @@ struct io_pgtable_cfg {
  */
 struct arm_lpae_io_pgtable_walk_data {
 	u64 ptes[4];
-	int level;
 };
 
 /**



[1]https://lore.kernel.org/all/Z1AtDgLD0SDUxDHl@google.com/

Thanks,
Mostafa

> 
> Rob Clark (4):
>   iommu/io-pgtable-arm: Make pgtable walker more generic
>   iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys
>   iommu/io-pgtable-arm: Add way to debug pgtable walk
>   drm/msm: Extend gpu devcore dumps with pgtbl info
> 
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c |  10 ++
>  drivers/gpu/drm/msm/msm_gpu.c           |   9 ++
>  drivers/gpu/drm/msm/msm_gpu.h           |   8 ++
>  drivers/gpu/drm/msm/msm_iommu.c         |  22 ++++
>  drivers/gpu/drm/msm/msm_mmu.h           |   3 +-
>  drivers/iommu/io-pgtable-arm.c          | 157 +++++++++++++++---------
>  include/linux/io-pgtable.h              |  15 +++
>  7 files changed, 167 insertions(+), 57 deletions(-)
> 
> -- 
> 2.47.1
> 

Re: [PATCH v11 0/4] io-pgtable-arm + drm/msm: Extend iova fault debugging

[Will Deacon]

On Tue, Jan 07, 2025 at 12:55:55PM +0000, Mostafa Saleh wrote:
> On Tue, Dec 10, 2024 at 08:51:18AM -0800, Rob Clark wrote:
> > From: Rob Clark <robdclark@chromium.org>
> > 
> > This series extends io-pgtable-arm with a method to retrieve the page
> > table entries traversed in the process of address translation, and then
> > beefs up drm/msm gpu devcore dump to include this (and additional info)
> > in the devcore dump.
> > 
> > This is a respin of https://patchwork.freedesktop.org/series/94968/
> > (minus a patch that was already merged)
> > 
> > v2:  Fix an armv7/32b build error in the last patch
> > v3:  Incorperate Will Deacon's suggestion to make the interface
> >      callback based.
> > v4:  Actually wire up the callback
> > v5:  Drop the callback approach
> > v6:  Make walk-data struct pgtable specific and rename
> >      io_pgtable_walk_data to arm_lpae_io_pgtable_walk_data
> > v7:  Re-use the pgtable walker added for arm_lpae_read_and_clear_dirty()
> > v8:  Pass pte pointer to callback so it can modify the actual pte
> > v9:  Fix selftests_running case
> > v10: Call visit cb for all nodes traversed, leave the decision about
> >      whether to care about non-leaf nodes to the callback
> > v11: Adjust logic in 3/4 [smostafa@]
> 
> I see the level initialization was not removed as it was in the diff[1], so it
> seems to me that’s redundant as the level is set anyway in the callback, and
> actually looking at that I see it’s not used or printed from the driver,
> so may it can be removed all together, anyway that’s nit that may be Will can
> fix it up while merging.
> 
> Otherwise, For the whole series
> Reviewed-by: Mostafa Saleh <smostafa@google.com>

I'm happy to drop the 'level' field if it's not used. We can add it back
if/when it's needed. Rob?

Will

Re: [PATCH v11 0/4] io-pgtable-arm + drm/msm: Extend iova fault debugging

[Rob Clark]

On Tue, Jan 7, 2025 at 4:58 AM Will Deacon <will@kernel.org> wrote:
>
> On Tue, Jan 07, 2025 at 12:55:55PM +0000, Mostafa Saleh wrote:
> > On Tue, Dec 10, 2024 at 08:51:18AM -0800, Rob Clark wrote:
> > > From: Rob Clark <robdclark@chromium.org>
> > >
> > > This series extends io-pgtable-arm with a method to retrieve the page
> > > table entries traversed in the process of address translation, and then
> > > beefs up drm/msm gpu devcore dump to include this (and additional info)
> > > in the devcore dump.
> > >
> > > This is a respin of https://patchwork.freedesktop.org/series/94968/
> > > (minus a patch that was already merged)
> > >
> > > v2:  Fix an armv7/32b build error in the last patch
> > > v3:  Incorperate Will Deacon's suggestion to make the interface
> > >      callback based.
> > > v4:  Actually wire up the callback
> > > v5:  Drop the callback approach
> > > v6:  Make walk-data struct pgtable specific and rename
> > >      io_pgtable_walk_data to arm_lpae_io_pgtable_walk_data
> > > v7:  Re-use the pgtable walker added for arm_lpae_read_and_clear_dirty()
> > > v8:  Pass pte pointer to callback so it can modify the actual pte
> > > v9:  Fix selftests_running case
> > > v10: Call visit cb for all nodes traversed, leave the decision about
> > >      whether to care about non-leaf nodes to the callback
> > > v11: Adjust logic in 3/4 [smostafa@]
> >
> > I see the level initialization was not removed as it was in the diff[1], so it
> > seems to me that’s redundant as the level is set anyway in the callback, and
> > actually looking at that I see it’s not used or printed from the driver,
> > so may it can be removed all together, anyway that’s nit that may be Will can
> > fix it up while merging.
> >
> > Otherwise, For the whole series
> > Reviewed-by: Mostafa Saleh <smostafa@google.com>
>
> I'm happy to drop the 'level' field if it's not used. We can add it back
> if/when it's needed. Rob?

That works for me, thx

BR,
-R

Re: [PATCH v11 0/4] io-pgtable-arm + drm/msm: Extend iova fault debugging

[Will Deacon]

On Tue, 10 Dec 2024 08:51:18 -0800, Rob Clark wrote:
> This series extends io-pgtable-arm with a method to retrieve the page
> table entries traversed in the process of address translation, and then
> beefs up drm/msm gpu devcore dump to include this (and additional info)
> in the devcore dump.
> 
> This is a respin of https://patchwork.freedesktop.org/series/94968/
> (minus a patch that was already merged)
> 
> [...]

Applied io-pgtable changes to iommu (arm/smmu/updates), thanks!

[1/4] iommu/io-pgtable-arm: Make pgtable walker more generic
      https://git.kernel.org/iommu/c/821500d5c597
[2/4] iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys
      https://git.kernel.org/iommu/c/d9e589e6ad73
[3/4] iommu/io-pgtable-arm: Add way to debug pgtable walk
      https://git.kernel.org/iommu/c/aff028a8192d

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev