diff mbox series

[v7,2/4] iommu/io-pgtable-arm: Re-use the pgtable walk for iova_to_phys

Message ID 20240820171652.145673-3-robdclark@gmail.com (mailing list archive)
State Superseded
Headers show
Series io-pgtable-arm + drm/msm: Extend iova fault debugging | expand

Commit Message

Rob Clark Aug. 20, 2024, 5:16 p.m. UTC 
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 | 73 +++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 37 deletions(-)

Comments

Will Deacon Aug. 23, 2024, 4:11 p.m. UTC | #1 
On Tue, Aug 20, 2024 at 10:16:45AM -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>
> ---
>  drivers/iommu/io-pgtable-arm.c | 73 +++++++++++++++++-----------------
>  1 file changed, 36 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> index b4bc358740e0..5fa1274a665a 100644
> --- a/drivers/iommu/io-pgtable-arm.c
> +++ b/drivers/iommu/io-pgtable-arm.c
> @@ -710,42 +710,6 @@ 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 {
>  	void				*data;
>  	int (*visit)(struct io_pgtable_walk_data *walk_data, int lvl,
> @@ -760,6 +724,41 @@ 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 pte, size_t size)
> +{
> +	struct iova_to_phys_data *data = walk_data->data;
> +	data->pte = pte;
> +	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)
> @@ -776,7 +775,7 @@ static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
>  		return 0;
>  	}
>  
> -	if (WARN_ON(!iopte_table(pte, lvl)))
> +	if (WARN_ON(!iopte_table(pte, lvl) && !selftest_running))

Why do you care about the selftest here?

Will
Rob Clark Aug. 23, 2024, 5:22 p.m. UTC | #2 
On Fri, Aug 23, 2024 at 9:11 AM Will Deacon <will@kernel.org> wrote:
>
> On Tue, Aug 20, 2024 at 10:16:45AM -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>
> > ---
> >  drivers/iommu/io-pgtable-arm.c | 73 +++++++++++++++++-----------------
> >  1 file changed, 36 insertions(+), 37 deletions(-)
> >
> > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> > index b4bc358740e0..5fa1274a665a 100644
> > --- a/drivers/iommu/io-pgtable-arm.c
> > +++ b/drivers/iommu/io-pgtable-arm.c
> > @@ -710,42 +710,6 @@ 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 {
> >       void                            *data;
> >       int (*visit)(struct io_pgtable_walk_data *walk_data, int lvl,
> > @@ -760,6 +724,41 @@ 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 pte, size_t size)
> > +{
> > +     struct iova_to_phys_data *data = walk_data->data;
> > +     data->pte = pte;
> > +     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)
> > @@ -776,7 +775,7 @@ static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
> >               return 0;
> >       }
> >
> > -     if (WARN_ON(!iopte_table(pte, lvl)))
> > +     if (WARN_ON(!iopte_table(pte, lvl) && !selftest_running))
>
> Why do you care about the selftest here?

Otherwise we see a flood of WARN_ON from negative tests in the selftests

BR,
-R

> Will
diff mbox series

Patch

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index b4bc358740e0..5fa1274a665a 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -710,42 +710,6 @@  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 {
 	void				*data;
 	int (*visit)(struct io_pgtable_walk_data *walk_data, int lvl,
@@ -760,6 +724,41 @@  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 pte, size_t size)
+{
+	struct iova_to_phys_data *data = walk_data->data;
+	data->pte = pte;
+	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)
@@ -776,7 +775,7 @@  static int io_pgtable_visit(struct arm_lpae_io_pgtable *data,
 		return 0;
 	}
 
-	if (WARN_ON(!iopte_table(pte, lvl)))
+	if (WARN_ON(!iopte_table(pte, lvl) && !selftest_running))
 		return -EINVAL;
 
 	ptep = iopte_deref(pte, data);