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[PATCH v10 2/4] iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys

Rob Clark posted 4 patches 1 year, 3 months ago
There is a newer version of this series
[PATCH v10 2/4] iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys
Posted by Rob Clark 1 year, 3 months ago 
From: Rob Clark <robdclark@chromium.org>

Re-use the generic pgtable walk path.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 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);
-- 
2.47.0
Re: [PATCH v10 2/4] iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys
Posted by Mostafa Saleh 1 year, 2 months ago 
Hi Rob,

On Mon, Oct 28, 2024 at 02:31:38PM -0700, Rob Clark wrote:
> 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>

Thanks,
Mostafa

> ---
>  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);
> -- 
> 2.47.0
>

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