[PATCH v3] drm/i915: Fix page cleanup on DMA remap failure

[PATCH v3] drm/i915: Fix page cleanup on DMA remap failure

[Brian Geffon]

When converting to folios the cleanup path of shmem_get_pages() was
missed. When a DMA remap fails and the max segment size is greater than
PAGE_SIZE it will attempt to retry the remap with a PAGE_SIZEd segment
size. The cleanup code isn't properly using the folio apis and as a
result isn't handling compound pages correctly.

v2 -> v3:
(Ville) Just use shmem_sg_free_table() as-is in the failure path of
shmem_get_pages(). shmem_sg_free_table() will clear mapping unevictable
but it will be reset when it retries in shmem_sg_alloc_table().

v1 -> v2:
(Ville) Fixed locations where we were not clearing mapping unevictable.

Cc: stable@vger.kernel.org
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Vidya Srinivas <vidya.srinivas@intel.com>
Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13487
Link: https://lore.kernel.org/lkml/20250116135636.410164-1-bgeffon@google.com/
Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a folio_batch")
Signed-off-by: Brian Geffon <bgeffon@google.com>
Suggested-by: Tomasz Figa <tfiga@google.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index fe69f2c8527d..ae3343c81a64 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -209,8 +209,6 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj)
 	struct address_space *mapping = obj->base.filp->f_mapping;
 	unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
 	struct sg_table *st;
-	struct sgt_iter sgt_iter;
-	struct page *page;
 	int ret;
 
 	/*
@@ -239,9 +237,7 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj)
 		 * for PAGE_SIZE chunks instead may be helpful.
 		 */
 		if (max_segment > PAGE_SIZE) {
-			for_each_sgt_page(page, sgt_iter, st)
-				put_page(page);
-			sg_free_table(st);
+			shmem_sg_free_table(st, mapping, false, false);
 			kfree(st);
 
 			max_segment = PAGE_SIZE;
-- 
2.48.1.262.g85cc9f2d1e-goog

RE: [PATCH v3] drm/i915: Fix page cleanup on DMA remap failure

[Cavitt, Jonathan]

-----Original Message-----
From: Intel-gfx <intel-gfx-bounces@lists.freedesktop.org> On Behalf Of Brian Geffon
Sent: Monday, January 27, 2025 12:44 PM
To: intel-gfx@lists.freedesktop.org
Cc: Wilson, Chris P <chris.p.wilson@intel.com>; Saarinen, Jani <jani.saarinen@intel.com>; Mistat, Tomasz <tomasz.mistat@intel.com>; Srinivas, Vidya <vidya.srinivas@intel.com>; ville.syrjala@linux.intel.com; jani.nikula@linux.intel.com; linux-kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; Joonas Lahtinen <joonas.lahtinen@linux.intel.com>; Brian Geffon <bgeffon@google.com>; stable@vger.kernel.org; Tomasz Figa <tfiga@google.com>
Subject: [PATCH v3] drm/i915: Fix page cleanup on DMA remap failure
> 
> When converting to folios the cleanup path of shmem_get_pages() was
> missed. When a DMA remap fails and the max segment size is greater than
> PAGE_SIZE it will attempt to retry the remap with a PAGE_SIZEd segment
> size. The cleanup code isn't properly using the folio apis and as a
> result isn't handling compound pages correctly.
> 
> v2 -> v3:
> (Ville) Just use shmem_sg_free_table() as-is in the failure path of
> shmem_get_pages(). shmem_sg_free_table() will clear mapping unevictable
> but it will be reset when it retries in shmem_sg_alloc_table().
> 
> v1 -> v2:
> (Ville) Fixed locations where we were not clearing mapping unevictable.
> 
> Cc: stable@vger.kernel.org
> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> Cc: Vidya Srinivas <vidya.srinivas@intel.com>
> Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13487
> Link: https://lore.kernel.org/lkml/20250116135636.410164-1-bgeffon@google.com/
> Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a folio_batch")
> Signed-off-by: Brian Geffon <bgeffon@google.com>
> Suggested-by: Tomasz Figa <tfiga@google.com>

Seems good to me.
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
-Jonathan Cavitt

> ---
>  drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> index fe69f2c8527d..ae3343c81a64 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> @@ -209,8 +209,6 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj)
>  	struct address_space *mapping = obj->base.filp->f_mapping;
>  	unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
>  	struct sg_table *st;
> -	struct sgt_iter sgt_iter;
> -	struct page *page;
>  	int ret;
>  
>  	/*
> @@ -239,9 +237,7 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj)
>  		 * for PAGE_SIZE chunks instead may be helpful.
>  		 */
>  		if (max_segment > PAGE_SIZE) {
> -			for_each_sgt_page(page, sgt_iter, st)
> -				put_page(page);
> -			sg_free_table(st);
> +			shmem_sg_free_table(st, mapping, false, false);
>  			kfree(st);
>  
>  			max_segment = PAGE_SIZE;
> -- 
> 2.48.1.262.g85cc9f2d1e-goog
> 
> 

RE: [PATCH v3] drm/i915: Fix page cleanup on DMA remap failure

[Srinivas, Vidya]

> -----Original Message-----
> From: Cavitt, Jonathan <jonathan.cavitt@intel.com>
> Sent: 28 January 2025 02:45
> To: Brian Geffon <bgeffon@google.com>; intel-gfx@lists.freedesktop.org
> Cc: Wilson, Chris P <chris.p.wilson@intel.com>; Saarinen, Jani
> <jani.saarinen@intel.com>; Mistat, Tomasz <tomasz.mistat@intel.com>;
> Srinivas, Vidya <vidya.srinivas@intel.com>; ville.syrjala@linux.intel.com;
> jani.nikula@linux.intel.com; linux-kernel@vger.kernel.org; dri-
> devel@lists.freedesktop.org; Joonas Lahtinen
> <joonas.lahtinen@linux.intel.com>; stable@vger.kernel.org; Tomasz Figa
> <tfiga@google.com>; Cavitt, Jonathan <jonathan.cavitt@intel.com>
> Subject: RE: [PATCH v3] drm/i915: Fix page cleanup on DMA remap failure
> 
> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@lists.freedesktop.org> On Behalf Of Brian
> Geffon
> Sent: Monday, January 27, 2025 12:44 PM
> To: intel-gfx@lists.freedesktop.org
> Cc: Wilson, Chris P <chris.p.wilson@intel.com>; Saarinen, Jani
> <jani.saarinen@intel.com>; Mistat, Tomasz <tomasz.mistat@intel.com>;
> Srinivas, Vidya <vidya.srinivas@intel.com>; ville.syrjala@linux.intel.com;
> jani.nikula@linux.intel.com; linux-kernel@vger.kernel.org; dri-
> devel@lists.freedesktop.org; Joonas Lahtinen
> <joonas.lahtinen@linux.intel.com>; Brian Geffon <bgeffon@google.com>;
> stable@vger.kernel.org; Tomasz Figa <tfiga@google.com>
> Subject: [PATCH v3] drm/i915: Fix page cleanup on DMA remap failure
> >
> > When converting to folios the cleanup path of shmem_get_pages() was
> > missed. When a DMA remap fails and the max segment size is greater
> > than PAGE_SIZE it will attempt to retry the remap with a PAGE_SIZEd
> > segment size. The cleanup code isn't properly using the folio apis and
> > as a result isn't handling compound pages correctly.
> >
> > v2 -> v3:
> > (Ville) Just use shmem_sg_free_table() as-is in the failure path of
> > shmem_get_pages(). shmem_sg_free_table() will clear mapping
> > unevictable but it will be reset when it retries in shmem_sg_alloc_table().
> >
> > v1 -> v2:
> > (Ville) Fixed locations where we were not clearing mapping unevictable.
> >
> > Cc: stable@vger.kernel.org
> > Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> > Cc: Vidya Srinivas <vidya.srinivas@intel.com>
> > Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13487
> > Link:
> > https://lore.kernel.org/lkml/20250116135636.410164-1-bgeffon@google.co
> > m/
> > Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a
> > folio_batch")
> > Signed-off-by: Brian Geffon <bgeffon@google.com>
> > Suggested-by: Tomasz Figa <tfiga@google.com>
> 
> Seems good to me.
> Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com> -Jonathan Cavitt
> 

Thank you so much to all.
Tested-by: Vidya Srinivas <vidya.srinivas@intel.com>

> > ---
> >  drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 6 +-----
> >  1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> > b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> > index fe69f2c8527d..ae3343c81a64 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> > @@ -209,8 +209,6 @@ static int shmem_get_pages(struct
> drm_i915_gem_object *obj)
> >  	struct address_space *mapping = obj->base.filp->f_mapping;
> >  	unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
> >  	struct sg_table *st;
> > -	struct sgt_iter sgt_iter;
> > -	struct page *page;
> >  	int ret;
> >
> >  	/*
> > @@ -239,9 +237,7 @@ static int shmem_get_pages(struct
> drm_i915_gem_object *obj)
> >  		 * for PAGE_SIZE chunks instead may be helpful.
> >  		 */
> >  		if (max_segment > PAGE_SIZE) {
> > -			for_each_sgt_page(page, sgt_iter, st)
> > -				put_page(page);
> > -			sg_free_table(st);
> > +			shmem_sg_free_table(st, mapping, false, false);
> >  			kfree(st);
> >
> >  			max_segment = PAGE_SIZE;
> > --
> > 2.48.1.262.g85cc9f2d1e-goog
> >
> >

Re: [PATCH v3] drm/i915: Fix page cleanup on DMA remap failure

[Ville Syrjälä]

On Mon, Jan 27, 2025 at 03:43:32PM -0500, Brian Geffon wrote:
> When converting to folios the cleanup path of shmem_get_pages() was
> missed. When a DMA remap fails and the max segment size is greater than
> PAGE_SIZE it will attempt to retry the remap with a PAGE_SIZEd segment
> size. The cleanup code isn't properly using the folio apis and as a
> result isn't handling compound pages correctly.
> 
> v2 -> v3:
> (Ville) Just use shmem_sg_free_table() as-is in the failure path of
> shmem_get_pages(). shmem_sg_free_table() will clear mapping unevictable
> but it will be reset when it retries in shmem_sg_alloc_table().
> 
> v1 -> v2:
> (Ville) Fixed locations where we were not clearing mapping unevictable.
> 
> Cc: stable@vger.kernel.org
> Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
> Cc: Vidya Srinivas <vidya.srinivas@intel.com>
> Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13487
> Link: https://lore.kernel.org/lkml/20250116135636.410164-1-bgeffon@google.com/
> Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a folio_batch")
> Signed-off-by: Brian Geffon <bgeffon@google.com>
> Suggested-by: Tomasz Figa <tfiga@google.com>

Thanks. Pushed to drm-intel-gt-next.

> ---
>  drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> index fe69f2c8527d..ae3343c81a64 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
> @@ -209,8 +209,6 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj)
>  	struct address_space *mapping = obj->base.filp->f_mapping;
>  	unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
>  	struct sg_table *st;
> -	struct sgt_iter sgt_iter;
> -	struct page *page;
>  	int ret;
>  
>  	/*
> @@ -239,9 +237,7 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj)
>  		 * for PAGE_SIZE chunks instead may be helpful.
>  		 */
>  		if (max_segment > PAGE_SIZE) {
> -			for_each_sgt_page(page, sgt_iter, st)
> -				put_page(page);
> -			sg_free_table(st);
> +			shmem_sg_free_table(st, mapping, false, false);
>  			kfree(st);
>  
>  			max_segment = PAGE_SIZE;
> -- 
> 2.48.1.262.g85cc9f2d1e-goog

-- 
Ville Syrjälä
Intel