Re: [PATCH] drm/ttm: don't set page->mapping
On Wed, Nov 25, 2020 at 05:28:32PM +0100, Daniel Vetter wrote: > On Wed, Nov 25, 2020 at 5:25 PM Daniel Vetter wrote: > > > > Random observation while trying to review Christian's patch series to > > stop looking at struct page for dma-buf imports. > > > > This was originally added in > > > > commit 58aa6622d32af7d2c08d45085f44c54554a16ed7 > > Author: Thomas Hellstrom > > Date: Fri Jan 3 11:47:23 2014 +0100 > > > > drm/ttm: Correctly set page mapping and -index members > > > > Needed for some vm operations; most notably unmap_mapping_range() with > > even_cows = 0. > > > > Signed-off-by: Thomas Hellstrom > > Reviewed-by: Brian Paul > > > > but we do not have a single caller of unmap_mapping_range with > > even_cows == 0. And all the gem drivers don't do this, so another > > small thing we could standardize between drm and ttm drivers. > > > > Plus I don't really see a need for unamp_mapping_range where we don't > > want to indiscriminately shoot down all ptes. > > > > Cc: Thomas Hellstrom > > Cc: Brian Paul > > Signed-off-by: Daniel Vetter > > Cc: Christian Koenig > > Cc: Huang Rui > > Apologies again, this shouldn't have been included. But at least I > have an idea now why this patch somehow was included in the git > send-email. Lovely interface :-/ I wrote a bit of a script around this because git send-email just too hard to use The key workflow change I made was to have it prepare all the emails to send and open them in an editor for review - exactly as they would be sent to the lists. It uses a empty 'cover-letter' commit and automatically transforms it into exactly the right stuff. Keeps track of everything you send in git, and there is a little tool to auto-run git range-diff to help build change logs.. https://github.com/jgunthorpe/Kernel-Maintainer-Tools/blob/master/gj_tools/cmd_send_patches.py I've been occasionaly wondering if I should suggest Konstantin add a sending side to b4, maybe using some of those ideas.. (careful if you run it, it does autosend without prompting) Jason ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] drm/ttm: don't set page->mapping
On Wed, Nov 25, 2020 at 06:11:29PM +, Christoph Hellwig wrote: > On Wed, Nov 25, 2020 at 02:06:06PM -0400, Jason Gunthorpe wrote: > > It uses a empty 'cover-letter' commit and automatically transforms it > > into exactly the right stuff. Keeps track of everything you send in > > git, and there is a little tool to auto-run git range-diff to help > > build change logs.. > > > > https://github.com/jgunthorpe/Kernel-Maintainer-Tools/blob/master/gj_tools/cmd_send_patches.py > > > > I've been occasionaly wondering if I should suggest Konstantin add a > > sending side to b4, maybe using some of those ideas.. > > > > (careful if you run it, it does autosend without prompting) > > The looks pretty fancy. Here is my trivial patchbomb.sh script > > #!/bin/sh > > COVERLETTER=$1 > PATCHES=$2 > > git send-email --annotate --to-cover --cc-cover $1 $2 > > still needs the git basecommit..endcommit notation, but it fires > up the series for review. annotate is OK, I used that for a long time.. My main gripe was it didn't setup the to/cc until after the annotate editor closes. Jason ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] drm/ttm: don't set page->mapping
Hi, On Wed, 25 Nov 2020 at 18:06, Jason Gunthorpe wrote: > On Wed, Nov 25, 2020 at 05:28:32PM +0100, Daniel Vetter wrote: > > Apologies again, this shouldn't have been included. But at least I > > have an idea now why this patch somehow was included in the git > > send-email. Lovely interface :-/ > > I wrote a bit of a script around this because git send-email just too > hard to use > > The key workflow change I made was to have it prepare all the emails > to send and open them in an editor for review - exactly as they would > be sent to the lists. > > It uses a empty 'cover-letter' commit and automatically transforms it > into exactly the right stuff. Keeps track of everything you send in > git, and there is a little tool to auto-run git range-diff to help > build change logs.. This sounds a fair bit like patman, which does something similar and also lets you annotate commit messages with changelogs. But of course, suggesting different methods of carving patches into stone tablets to someone who's written their own, is even more of a windmill tilt than rDMA. ;) Cheers, Daniel ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] drm/ttm: don't set page->mapping
On Wed, Nov 25, 2020 at 5:25 PM Daniel Vetter wrote:
>
> Random observation while trying to review Christian's patch series to
> stop looking at struct page for dma-buf imports.
>
> This was originally added in
>
> commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
> Author: Thomas Hellstrom
> Date: Fri Jan 3 11:47:23 2014 +0100
>
> drm/ttm: Correctly set page mapping and -index members
>
> Needed for some vm operations; most notably unmap_mapping_range() with
> even_cows = 0.
>
> Signed-off-by: Thomas Hellstrom
> Reviewed-by: Brian Paul
>
> but we do not have a single caller of unmap_mapping_range with
> even_cows == 0. And all the gem drivers don't do this, so another
> small thing we could standardize between drm and ttm drivers.
>
> Plus I don't really see a need for unamp_mapping_range where we don't
> want to indiscriminately shoot down all ptes.
>
> Cc: Thomas Hellstrom
> Cc: Brian Paul
> Signed-off-by: Daniel Vetter
> Cc: Christian Koenig
> Cc: Huang Rui
Apologies again, this shouldn't have been included. But at least I
have an idea now why this patch somehow was included in the git
send-email. Lovely interface :-/
-Daniel
> ---
> drivers/gpu/drm/ttm/ttm_tt.c | 12
> 1 file changed, 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> index da9eeffe0c6d..5b2eb6d58bb7 100644
> --- a/drivers/gpu/drm/ttm/ttm_tt.c
> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> @@ -284,17 +284,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
> ttm_tt *ttm)
> return ret;
> }
>
> -static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt
> *ttm)
> -{
> - pgoff_t i;
> -
> - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> - return;
> -
> - for (i = 0; i < ttm->num_pages; ++i)
> - ttm->pages[i]->mapping = bdev->dev_mapping;
> -}
> -
> int ttm_tt_populate(struct ttm_bo_device *bdev,
> struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
> {
> @@ -313,7 +302,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
> if (ret)
> return ret;
>
> - ttm_tt_add_mapping(bdev, ttm);
> ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
> if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
> ret = ttm_tt_swapin(ttm);
> --
> 2.29.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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[PATCH] drm/ttm: don't set page->mapping
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index da9eeffe0c6d..5b2eb6d58bb7 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -284,17 +284,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -313,7 +302,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
--
2.29.2
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Re: [PATCH] drm/ttm: don't set page->mapping
On Fri, Nov 20, 2020 at 11:08:31AM +0100, Christian König wrote:
> Am 20.11.20 um 11:05 schrieb Daniel Vetter:
> > On Fri, Nov 20, 2020 at 11:04 AM Christian König
> > wrote:
> > > Am 20.11.20 um 10:54 schrieb Daniel Vetter:
> > > > Random observation while trying to review Christian's patch series to
> > > > stop looking at struct page for dma-buf imports.
> > > >
> > > > This was originally added in
> > > >
> > > > commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
> > > > Author: Thomas Hellstrom
> > > > Date: Fri Jan 3 11:47:23 2014 +0100
> > > >
> > > > drm/ttm: Correctly set page mapping and -index members
> > > >
> > > > Needed for some vm operations; most notably unmap_mapping_range()
> > > > with
> > > > even_cows = 0.
> > > >
> > > > Signed-off-by: Thomas Hellstrom
> > > > Reviewed-by: Brian Paul
> > > >
> > > > but we do not have a single caller of unmap_mapping_range with
> > > > even_cows == 0. And all the gem drivers don't do this, so another
> > > > small thing we could standardize between drm and ttm drivers.
> > > >
> > > > Plus I don't really see a need for unamp_mapping_range where we don't
> > > > want to indiscriminately shoot down all ptes.
> > > >
> > > > Cc: Thomas Hellstrom
> > > > Cc: Brian Paul
> > > > Signed-off-by: Daniel Vetter
> > > > Cc: Christian Koenig
> > > > Cc: Huang Rui
> > > This is still a NAK as long as we can't come up with a better way to
> > > track TTMs page allocations.
> > >
> > > Additional to that page_mapping() is used quite extensively in the mm
> > > code and I'm not sure if that isn't needed for other stuff as well.
> > Apologies, I'm honestly not quite sure how this lone patch here ended
> > up in this submission. I didn't want to send it out.
>
> No problem.
>
> But looking a bit deeper into the mm code that other drm drivers don't set
> this correctly and still use unmap_mapping_range() sounds like quite a bug
> to me.
>
> Going to track down what exactly that is used for.
Pagecache shootdown. unmap_mapping_range only shoots down from the virtual
side. Since that's all we care about, we don't need to set up the
address_space in the page.
-Daniel
>
> Christian.
>
> > -Daniel
> >
> > > Regards,
> > > Christian.
> > >
> > > > ---
> > > >drivers/gpu/drm/ttm/ttm_tt.c | 12
> > > >1 file changed, 12 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> > > > index da9eeffe0c6d..5b2eb6d58bb7 100644
> > > > --- a/drivers/gpu/drm/ttm/ttm_tt.c
> > > > +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> > > > @@ -284,17 +284,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev,
> > > > struct ttm_tt *ttm)
> > > >return ret;
> > > >}
> > > >
> > > > -static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct
> > > > ttm_tt *ttm)
> > > > -{
> > > > - pgoff_t i;
> > > > -
> > > > - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> > > > - return;
> > > > -
> > > > - for (i = 0; i < ttm->num_pages; ++i)
> > > > - ttm->pages[i]->mapping = bdev->dev_mapping;
> > > > -}
> > > > -
> > > >int ttm_tt_populate(struct ttm_bo_device *bdev,
> > > >struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
> > > >{
> > > > @@ -313,7 +302,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
> > > >if (ret)
> > > >return ret;
> > > >
> > > > - ttm_tt_add_mapping(bdev, ttm);
> > > >ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
> > > >if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
> > > >ret = ttm_tt_swapin(ttm);
> >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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Re: [PATCH] drm/ttm: don't set page->mapping
Am 20.11.20 um 11:05 schrieb Daniel Vetter:
On Fri, Nov 20, 2020 at 11:04 AM Christian König
wrote:
Am 20.11.20 um 10:54 schrieb Daniel Vetter:
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
This is still a NAK as long as we can't come up with a better way to
track TTMs page allocations.
Additional to that page_mapping() is used quite extensively in the mm
code and I'm not sure if that isn't needed for other stuff as well.
Apologies, I'm honestly not quite sure how this lone patch here ended
up in this submission. I didn't want to send it out.
No problem.
But looking a bit deeper into the mm code that other drm drivers don't
set this correctly and still use unmap_mapping_range() sounds like quite
a bug to me.
Going to track down what exactly that is used for.
Christian.
-Daniel
Regards,
Christian.
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index da9eeffe0c6d..5b2eb6d58bb7 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -284,17 +284,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -313,7 +302,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
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Re: [PATCH] drm/ttm: don't set page->mapping
On Fri, Nov 20, 2020 at 11:04 AM Christian König
wrote:
>
> Am 20.11.20 um 10:54 schrieb Daniel Vetter:
> > Random observation while trying to review Christian's patch series to
> > stop looking at struct page for dma-buf imports.
> >
> > This was originally added in
> >
> > commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
> > Author: Thomas Hellstrom
> > Date: Fri Jan 3 11:47:23 2014 +0100
> >
> > drm/ttm: Correctly set page mapping and -index members
> >
> > Needed for some vm operations; most notably unmap_mapping_range() with
> > even_cows = 0.
> >
> > Signed-off-by: Thomas Hellstrom
> > Reviewed-by: Brian Paul
> >
> > but we do not have a single caller of unmap_mapping_range with
> > even_cows == 0. And all the gem drivers don't do this, so another
> > small thing we could standardize between drm and ttm drivers.
> >
> > Plus I don't really see a need for unamp_mapping_range where we don't
> > want to indiscriminately shoot down all ptes.
> >
> > Cc: Thomas Hellstrom
> > Cc: Brian Paul
> > Signed-off-by: Daniel Vetter
> > Cc: Christian Koenig
> > Cc: Huang Rui
>
> This is still a NAK as long as we can't come up with a better way to
> track TTMs page allocations.
>
> Additional to that page_mapping() is used quite extensively in the mm
> code and I'm not sure if that isn't needed for other stuff as well.
Apologies, I'm honestly not quite sure how this lone patch here ended
up in this submission. I didn't want to send it out.
-Daniel
>
> Regards,
> Christian.
>
> > ---
> > drivers/gpu/drm/ttm/ttm_tt.c | 12
> > 1 file changed, 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> > index da9eeffe0c6d..5b2eb6d58bb7 100644
> > --- a/drivers/gpu/drm/ttm/ttm_tt.c
> > +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> > @@ -284,17 +284,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
> > ttm_tt *ttm)
> > return ret;
> > }
> >
> > -static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt
> > *ttm)
> > -{
> > - pgoff_t i;
> > -
> > - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> > - return;
> > -
> > - for (i = 0; i < ttm->num_pages; ++i)
> > - ttm->pages[i]->mapping = bdev->dev_mapping;
> > -}
> > -
> > int ttm_tt_populate(struct ttm_bo_device *bdev,
> > struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
> > {
> > @@ -313,7 +302,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
> > if (ret)
> > return ret;
> >
> > - ttm_tt_add_mapping(bdev, ttm);
> > ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
> > if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
> > ret = ttm_tt_swapin(ttm);
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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Re: [PATCH] drm/ttm: don't set page->mapping
Am 20.11.20 um 10:54 schrieb Daniel Vetter:
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
This is still a NAK as long as we can't come up with a better way to
track TTMs page allocations.
Additional to that page_mapping() is used quite extensively in the mm
code and I'm not sure if that isn't needed for other stuff as well.
Regards,
Christian.
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index da9eeffe0c6d..5b2eb6d58bb7 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -284,17 +284,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -313,7 +302,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
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[PATCH] drm/ttm: don't set page->mapping
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index da9eeffe0c6d..5b2eb6d58bb7 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -284,17 +284,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -313,7 +302,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
--
2.29.2
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Re: [PATCH] drm/ttm: don't set page->mapping
Am 05.11.20 um 17:37 schrieb Daniel Vetter: [SNIP] NAK, we use this to determine if a pages belongs to the driver or not in amdgpu for example. Mostly used for debugging, but I would really like to keep that. Can you pls point me at that code? A quick grep hasn't really found much at all. See amdgpu_iomem_read() for an example: Why do you reject this? When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise give the same access as /dev/mem to system memory and that is forbidden. But as I noted this is just for the debugfs file. Ah, there's a config option for that. Plus it's debugfs, anything goes in debugfs, but if you're worried about that hole we should just disable the entire debugfs file for CONFIG_STRICT_DEVMEM. I can perhaps throw that on top, that follow_pfn patch series I'm baking is all about this kind of fun. And exactly that would get a NAK from us. We have specially created that debugfs file as an alternative when CONFIG_STRICT_DEVMEM is set. Uh that doesn't work if you work around core restrictions with your own debugfs paths. That's why we have the restriction to check the mapping of the pages. This way we only expose the memory which was allocated by our driver and don't allow any uncontrolled access to the whole system memory. We have something similar for radeon as well, but there we have a global GART table which we can use for validating stuff. The check doesn't take any locks over the check and copy*user, I don't think it's protecting anything really against somewhat adverse userspace. You mean that it's racing with freeing the pages? Yes that is an obvious problem, but we already had the same issue for radeon as well. On the other hand we could easily prevent that with a lock. I mean fundamentally locking down stuff like STRICT_DEVMEM or all the others makes debugging harder, that's kinda the expected tradeoff. Well we just wanted to have the same debugging functionality we had for radeon. As you said debugfs is a rabbit hole regarding attack vectors anyway. If you are root you can just go to /sys and start reprogramming the hardware to do what you want to do. Regards, Christian. Maybe you can do fun like this in your dkms, but not in upstream. Like if this was specifically created to work around CONFIG_STRICT_DEVMEM (and it sounds like that) then I think this should never have landed in upstream to begin with. I'm also kinda confused that there's distros with CONFIG_STRICT_DEVMEM which allow debugfs. debugfs is a pretty bad root hole all around, or at least that's been the assumption all the time. Yeah, completely agree :) But that's not my problem. I guess I'll do another rfc series and poke a pile of people ... seems to be a habit I'm developing :-) -Daniel ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] drm/ttm: don't set page->mapping
On Thu, Nov 5, 2020 at 4:15 PM Christian König wrote: > > Am 05.11.20 um 15:38 schrieb Daniel Vetter: > > On Thu, Nov 5, 2020 at 3:31 PM Daniel Vetter wrote: > >> On Thu, Nov 5, 2020 at 2:22 PM Christian König > >> wrote: > >>> Am 05.11.20 um 14:20 schrieb Daniel Vetter: > On Thu, Nov 05, 2020 at 01:56:22PM +0100, Christian König wrote: > > Am 05.11.20 um 13:50 schrieb Daniel Vetter: > >> On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote: > >>> Am 05.11.20 um 10:11 schrieb Daniel Vetter: > On Thu, Nov 5, 2020 at 9:00 AM Christian König > wrote: > > Am 04.11.20 um 17:50 schrieb Daniel Vetter: > >> Random observation while trying to review Christian's patch series > >> to > >> stop looking at struct page for dma-buf imports. > >> > >> This was originally added in > >> > >> commit 58aa6622d32af7d2c08d45085f44c54554a16ed7 > >> Author: Thomas Hellstrom > >> Date: Fri Jan 3 11:47:23 2014 +0100 > >> > >> drm/ttm: Correctly set page mapping and -index members > >> > >> Needed for some vm operations; most notably > >> unmap_mapping_range() with > >> even_cows = 0. > >> > >> Signed-off-by: Thomas Hellstrom > >> Reviewed-by: Brian Paul > >> > >> but we do not have a single caller of unmap_mapping_range with > >> even_cows == 0. And all the gem drivers don't do this, so another > >> small thing we could standardize between drm and ttm drivers. > >> > >> Plus I don't really see a need for unamp_mapping_range where we > >> don't > >> want to indiscriminately shoot down all ptes. > > NAK, we use this to determine if a pages belongs to the driver or > > not in > > amdgpu for example. > > > > Mostly used for debugging, but I would really like to keep that. > Can you pls point me at that code? A quick grep hasn't really found > much at all. > >>> See amdgpu_iomem_read() for an example: > >> Why do you reject this? > > When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise > > give the > > same access as /dev/mem to system memory and that is forbidden. But as I > > noted this is just for the debugfs file. > Ah, there's a config option for that. Plus it's debugfs, anything goes in > debugfs, but if you're worried about that hole we should just disable the > entire debugfs file for CONFIG_STRICT_DEVMEM. I can perhaps throw that on > top, that follow_pfn patch series I'm baking is all about this kind of > fun. > >>> And exactly that would get a NAK from us. > >>> > >>> We have specially created that debugfs file as an alternative when > >>> CONFIG_STRICT_DEVMEM is set. > >> Uh that doesn't work if you work around core restrictions with your > >> own debugfs paths. > > That's why we have the restriction to check the mapping of the pages. > > This way we only expose the memory which was allocated by our driver and > don't allow any uncontrolled access to the whole system memory. > > We have something similar for radeon as well, but there we have a global > GART table which we can use for validating stuff. The check doesn't take any locks over the check and copy*user, I don't think it's protecting anything really against somewhat adverse userspace. I mean fundamentally locking down stuff like STRICT_DEVMEM or all the others makes debugging harder, that's kinda the expected tradeoff. > >> Maybe you can do fun like this in your dkms, but > >> not in upstream. Like if this was specifically created to work around > >> CONFIG_STRICT_DEVMEM (and it sounds like that) then I think this > >> should never have landed in upstream to begin with. > > I'm also kinda confused that there's distros with CONFIG_STRICT_DEVMEM > > which allow debugfs. debugfs is a pretty bad root hole all around, or > > at least that's been the assumption all the time. > > Yeah, completely agree :) But that's not my problem. I guess I'll do another rfc series and poke a pile of people ... seems to be a habit I'm developing :-) -Daniel > > Christian. > > > -Daniel > > > > When I tried a few years ago to not set the page->mapping I immediately > > ran > > into issues with our eviction test. So I think that this is used > > elsewhere > > as well. > That's the kind of interaction I'm worried about here tbh. If this does > some kind of shrinking of some sorts, I think a real shrinker should take > over. > > An improved grep shows nothing else, so the only the above is the only > thing I can think of. What kind of eviction test goes boom if you clear > ->mapping here? I'd be happy to type up the clever trick for the debugfs > files. > -Daniel > > >
Re: [PATCH] drm/ttm: don't set page->mapping
Am 05.11.20 um 15:38 schrieb Daniel Vetter: On Thu, Nov 5, 2020 at 3:31 PM Daniel Vetter wrote: On Thu, Nov 5, 2020 at 2:22 PM Christian König wrote: Am 05.11.20 um 14:20 schrieb Daniel Vetter: On Thu, Nov 05, 2020 at 01:56:22PM +0100, Christian König wrote: Am 05.11.20 um 13:50 schrieb Daniel Vetter: On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote: Am 05.11.20 um 10:11 schrieb Daniel Vetter: On Thu, Nov 5, 2020 at 9:00 AM Christian König wrote: Am 04.11.20 um 17:50 schrieb Daniel Vetter: Random observation while trying to review Christian's patch series to stop looking at struct page for dma-buf imports. This was originally added in commit 58aa6622d32af7d2c08d45085f44c54554a16ed7 Author: Thomas Hellstrom Date: Fri Jan 3 11:47:23 2014 +0100 drm/ttm: Correctly set page mapping and -index members Needed for some vm operations; most notably unmap_mapping_range() with even_cows = 0. Signed-off-by: Thomas Hellstrom Reviewed-by: Brian Paul but we do not have a single caller of unmap_mapping_range with even_cows == 0. And all the gem drivers don't do this, so another small thing we could standardize between drm and ttm drivers. Plus I don't really see a need for unamp_mapping_range where we don't want to indiscriminately shoot down all ptes. NAK, we use this to determine if a pages belongs to the driver or not in amdgpu for example. Mostly used for debugging, but I would really like to keep that. Can you pls point me at that code? A quick grep hasn't really found much at all. See amdgpu_iomem_read() for an example: Why do you reject this? When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise give the same access as /dev/mem to system memory and that is forbidden. But as I noted this is just for the debugfs file. Ah, there's a config option for that. Plus it's debugfs, anything goes in debugfs, but if you're worried about that hole we should just disable the entire debugfs file for CONFIG_STRICT_DEVMEM. I can perhaps throw that on top, that follow_pfn patch series I'm baking is all about this kind of fun. And exactly that would get a NAK from us. We have specially created that debugfs file as an alternative when CONFIG_STRICT_DEVMEM is set. Uh that doesn't work if you work around core restrictions with your own debugfs paths. That's why we have the restriction to check the mapping of the pages. This way we only expose the memory which was allocated by our driver and don't allow any uncontrolled access to the whole system memory. We have something similar for radeon as well, but there we have a global GART table which we can use for validating stuff. Maybe you can do fun like this in your dkms, but not in upstream. Like if this was specifically created to work around CONFIG_STRICT_DEVMEM (and it sounds like that) then I think this should never have landed in upstream to begin with. I'm also kinda confused that there's distros with CONFIG_STRICT_DEVMEM which allow debugfs. debugfs is a pretty bad root hole all around, or at least that's been the assumption all the time. Yeah, completely agree :) But that's not my problem. Christian. -Daniel When I tried a few years ago to not set the page->mapping I immediately ran into issues with our eviction test. So I think that this is used elsewhere as well. That's the kind of interaction I'm worried about here tbh. If this does some kind of shrinking of some sorts, I think a real shrinker should take over. An improved grep shows nothing else, so the only the above is the only thing I can think of. What kind of eviction test goes boom if you clear ->mapping here? I'd be happy to type up the clever trick for the debugfs files. -Daniel Regards, Christian. If this is to avoid issues with userptr, then I think there's a simple trick: - grab page reference - recheck that the iova still points at the same address - do read/write, safe in the knowledge that this page cannot be reused for anything else - drop page reference Of course this can still race against iova updates, but that seems to be a fundamental part of your debug interface here. Or am I missing something? Just pondering this more since setting the page->mapping pointer for just this seems somewhat wild abuse of ->mapping semantics :-) -Daniel if (p->mapping != adev->mman.bdev.dev_mapping) return -EPERM; Christian. -Daniel Christian. Cc: Thomas Hellstrom Cc: Brian Paul Signed-off-by: Daniel Vetter Cc: Christian Koenig Cc: Huang Rui --- drivers/gpu/drm/ttm/ttm_tt.c | 12 1 file changed, 12 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c index 8861a74ac335..438ea43fd8c1 100644 --- a/drivers/gpu/drm/ttm/ttm_tt.c +++ b/drivers/gpu/drm/ttm/ttm_tt.c @@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct ttm_tt *ttm) return ret;
Re: [PATCH] drm/ttm: don't set page->mapping
On Thu, Nov 5, 2020 at 3:31 PM Daniel Vetter wrote: > > On Thu, Nov 5, 2020 at 2:22 PM Christian König > wrote: > > > > Am 05.11.20 um 14:20 schrieb Daniel Vetter: > > > On Thu, Nov 05, 2020 at 01:56:22PM +0100, Christian König wrote: > > >> Am 05.11.20 um 13:50 schrieb Daniel Vetter: > > >>> On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote: > > Am 05.11.20 um 10:11 schrieb Daniel Vetter: > > > On Thu, Nov 5, 2020 at 9:00 AM Christian König > > > wrote: > > >> Am 04.11.20 um 17:50 schrieb Daniel Vetter: > > >>> Random observation while trying to review Christian's patch series > > >>> to > > >>> stop looking at struct page for dma-buf imports. > > >>> > > >>> This was originally added in > > >>> > > >>> commit 58aa6622d32af7d2c08d45085f44c54554a16ed7 > > >>> Author: Thomas Hellstrom > > >>> Date: Fri Jan 3 11:47:23 2014 +0100 > > >>> > > >>> drm/ttm: Correctly set page mapping and -index members > > >>> > > >>> Needed for some vm operations; most notably > > >>> unmap_mapping_range() with > > >>> even_cows = 0. > > >>> > > >>> Signed-off-by: Thomas Hellstrom > > >>> Reviewed-by: Brian Paul > > >>> > > >>> but we do not have a single caller of unmap_mapping_range with > > >>> even_cows == 0. And all the gem drivers don't do this, so another > > >>> small thing we could standardize between drm and ttm drivers. > > >>> > > >>> Plus I don't really see a need for unamp_mapping_range where we > > >>> don't > > >>> want to indiscriminately shoot down all ptes. > > >> NAK, we use this to determine if a pages belongs to the driver or > > >> not in > > >> amdgpu for example. > > >> > > >> Mostly used for debugging, but I would really like to keep that. > > > Can you pls point me at that code? A quick grep hasn't really found > > > much at all. > > See amdgpu_iomem_read() for an example: > > >>> Why do you reject this? > > >> When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise give > > >> the > > >> same access as /dev/mem to system memory and that is forbidden. But as I > > >> noted this is just for the debugfs file. > > > Ah, there's a config option for that. Plus it's debugfs, anything goes in > > > debugfs, but if you're worried about that hole we should just disable the > > > entire debugfs file for CONFIG_STRICT_DEVMEM. I can perhaps throw that on > > > top, that follow_pfn patch series I'm baking is all about this kind of > > > fun. > > > > And exactly that would get a NAK from us. > > > > We have specially created that debugfs file as an alternative when > > CONFIG_STRICT_DEVMEM is set. > > Uh that doesn't work if you work around core restrictions with your > own debugfs paths. Maybe you can do fun like this in your dkms, but > not in upstream. Like if this was specifically created to work around > CONFIG_STRICT_DEVMEM (and it sounds like that) then I think this > should never have landed in upstream to begin with. I'm also kinda confused that there's distros with CONFIG_STRICT_DEVMEM which allow debugfs. debugfs is a pretty bad root hole all around, or at least that's been the assumption all the time. -Daniel > > >> When I tried a few years ago to not set the page->mapping I immediately > > >> ran > > >> into issues with our eviction test. So I think that this is used > > >> elsewhere > > >> as well. > > > That's the kind of interaction I'm worried about here tbh. If this does > > > some kind of shrinking of some sorts, I think a real shrinker should take > > > over. > > > > > > An improved grep shows nothing else, so the only the above is the only > > > thing I can think of. What kind of eviction test goes boom if you clear > > > ->mapping here? I'd be happy to type up the clever trick for the debugfs > > > files. > > > -Daniel > > > > > >> Regards, > > >> Christian. > > >> > > >>> If this is to avoid issues with userptr, then I think there's a simple > > >>> trick: > > >>> - grab page reference > > >>> - recheck that the iova still points at the same address > > >>> - do read/write, safe in the knowledge that this page cannot be reused > > >>> for > > >>> anything else > > >>> - drop page reference > > >>> > > >>> Of course this can still race against iova updates, but that seems to > > >>> be a > > >>> fundamental part of your debug interface here. > > >>> > > >>> Or am I missing something? > > >>> > > >>> Just pondering this more since setting the page->mapping pointer for > > >>> just > > >>> this seems somewhat wild abuse of ->mapping semantics :-) > > >>> -Daniel > > >>> > > > if (p->mapping != adev->mman.bdev.dev_mapping) > > > return -EPERM; > > Christian. > > > > > -Daniel > > > > > >> Christian. > > >> > > >>> Cc: Thomas Hellstrom > > >>> Cc: Brian Paul > >
Re: [PATCH] drm/ttm: don't set page->mapping
On Thu, Nov 5, 2020 at 2:22 PM Christian König wrote: > > Am 05.11.20 um 14:20 schrieb Daniel Vetter: > > On Thu, Nov 05, 2020 at 01:56:22PM +0100, Christian König wrote: > >> Am 05.11.20 um 13:50 schrieb Daniel Vetter: > >>> On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote: > Am 05.11.20 um 10:11 schrieb Daniel Vetter: > > On Thu, Nov 5, 2020 at 9:00 AM Christian König > > wrote: > >> Am 04.11.20 um 17:50 schrieb Daniel Vetter: > >>> Random observation while trying to review Christian's patch series to > >>> stop looking at struct page for dma-buf imports. > >>> > >>> This was originally added in > >>> > >>> commit 58aa6622d32af7d2c08d45085f44c54554a16ed7 > >>> Author: Thomas Hellstrom > >>> Date: Fri Jan 3 11:47:23 2014 +0100 > >>> > >>> drm/ttm: Correctly set page mapping and -index members > >>> > >>> Needed for some vm operations; most notably > >>> unmap_mapping_range() with > >>> even_cows = 0. > >>> > >>> Signed-off-by: Thomas Hellstrom > >>> Reviewed-by: Brian Paul > >>> > >>> but we do not have a single caller of unmap_mapping_range with > >>> even_cows == 0. And all the gem drivers don't do this, so another > >>> small thing we could standardize between drm and ttm drivers. > >>> > >>> Plus I don't really see a need for unamp_mapping_range where we don't > >>> want to indiscriminately shoot down all ptes. > >> NAK, we use this to determine if a pages belongs to the driver or not > >> in > >> amdgpu for example. > >> > >> Mostly used for debugging, but I would really like to keep that. > > Can you pls point me at that code? A quick grep hasn't really found > > much at all. > See amdgpu_iomem_read() for an example: > >>> Why do you reject this? > >> When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise give > >> the > >> same access as /dev/mem to system memory and that is forbidden. But as I > >> noted this is just for the debugfs file. > > Ah, there's a config option for that. Plus it's debugfs, anything goes in > > debugfs, but if you're worried about that hole we should just disable the > > entire debugfs file for CONFIG_STRICT_DEVMEM. I can perhaps throw that on > > top, that follow_pfn patch series I'm baking is all about this kind of > > fun. > > And exactly that would get a NAK from us. > > We have specially created that debugfs file as an alternative when > CONFIG_STRICT_DEVMEM is set. Uh that doesn't work if you work around core restrictions with your own debugfs paths. Maybe you can do fun like this in your dkms, but not in upstream. Like if this was specifically created to work around CONFIG_STRICT_DEVMEM (and it sounds like that) then I think this should never have landed in upstream to begin with. -Daniel > > Regards, > Christian. > > > > >> When I tried a few years ago to not set the page->mapping I immediately ran > >> into issues with our eviction test. So I think that this is used elsewhere > >> as well. > > That's the kind of interaction I'm worried about here tbh. If this does > > some kind of shrinking of some sorts, I think a real shrinker should take > > over. > > > > An improved grep shows nothing else, so the only the above is the only > > thing I can think of. What kind of eviction test goes boom if you clear > > ->mapping here? I'd be happy to type up the clever trick for the debugfs > > files. > > -Daniel > > > >> Regards, > >> Christian. > >> > >>> If this is to avoid issues with userptr, then I think there's a simple > >>> trick: > >>> - grab page reference > >>> - recheck that the iova still points at the same address > >>> - do read/write, safe in the knowledge that this page cannot be reused for > >>> anything else > >>> - drop page reference > >>> > >>> Of course this can still race against iova updates, but that seems to be a > >>> fundamental part of your debug interface here. > >>> > >>> Or am I missing something? > >>> > >>> Just pondering this more since setting the page->mapping pointer for just > >>> this seems somewhat wild abuse of ->mapping semantics :-) > >>> -Daniel > >>> > > if (p->mapping != adev->mman.bdev.dev_mapping) > > return -EPERM; > Christian. > > > -Daniel > > > >> Christian. > >> > >>> Cc: Thomas Hellstrom > >>> Cc: Brian Paul > >>> Signed-off-by: Daniel Vetter > >>> Cc: Christian Koenig > >>> Cc: Huang Rui > >>> --- > >>> drivers/gpu/drm/ttm/ttm_tt.c | 12 > >>> 1 file changed, 12 deletions(-) > >>> > >>> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c > >>> b/drivers/gpu/drm/ttm/ttm_tt.c > >>> index 8861a74ac335..438ea43fd8c1 100644 > >>> --- a/drivers/gpu/drm/ttm/ttm_tt.c > >>> +++ b/drivers/gpu/drm/ttm/ttm_tt.c > >>> @@ -291,17 +291,6 @@ int
Re: [PATCH] drm/ttm: don't set page->mapping
Am 05.11.20 um 14:20 schrieb Daniel Vetter:
On Thu, Nov 05, 2020 at 01:56:22PM +0100, Christian König wrote:
Am 05.11.20 um 13:50 schrieb Daniel Vetter:
On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote:
Am 05.11.20 um 10:11 schrieb Daniel Vetter:
On Thu, Nov 5, 2020 at 9:00 AM Christian König wrote:
Am 04.11.20 um 17:50 schrieb Daniel Vetter:
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
NAK, we use this to determine if a pages belongs to the driver or not in
amdgpu for example.
Mostly used for debugging, but I would really like to keep that.
Can you pls point me at that code? A quick grep hasn't really found much at all.
See amdgpu_iomem_read() for an example:
Why do you reject this?
When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise give the
same access as /dev/mem to system memory and that is forbidden. But as I
noted this is just for the debugfs file.
Ah, there's a config option for that. Plus it's debugfs, anything goes in
debugfs, but if you're worried about that hole we should just disable the
entire debugfs file for CONFIG_STRICT_DEVMEM. I can perhaps throw that on
top, that follow_pfn patch series I'm baking is all about this kind of
fun.
And exactly that would get a NAK from us.
We have specially created that debugfs file as an alternative when
CONFIG_STRICT_DEVMEM is set.
Regards,
Christian.
When I tried a few years ago to not set the page->mapping I immediately ran
into issues with our eviction test. So I think that this is used elsewhere
as well.
That's the kind of interaction I'm worried about here tbh. If this does
some kind of shrinking of some sorts, I think a real shrinker should take
over.
An improved grep shows nothing else, so the only the above is the only
thing I can think of. What kind of eviction test goes boom if you clear
->mapping here? I'd be happy to type up the clever trick for the debugfs
files.
-Daniel
Regards,
Christian.
If this is to avoid issues with userptr, then I think there's a simple
trick:
- grab page reference
- recheck that the iova still points at the same address
- do read/write, safe in the knowledge that this page cannot be reused for
anything else
- drop page reference
Of course this can still race against iova updates, but that seems to be a
fundamental part of your debug interface here.
Or am I missing something?
Just pondering this more since setting the page->mapping pointer for just
this seems somewhat wild abuse of ->mapping semantics :-)
-Daniel
if (p->mapping != adev->mman.bdev.dev_mapping)
return -EPERM;
Christian.
-Daniel
Christian.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 8861a74ac335..438ea43fd8c1 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -320,7 +309,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
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Re: [PATCH] drm/ttm: don't set page->mapping
On Thu, Nov 05, 2020 at 01:56:22PM +0100, Christian König wrote:
> Am 05.11.20 um 13:50 schrieb Daniel Vetter:
> > On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote:
> > > Am 05.11.20 um 10:11 schrieb Daniel Vetter:
> > > > On Thu, Nov 5, 2020 at 9:00 AM Christian König
> > > > wrote:
> > > > > Am 04.11.20 um 17:50 schrieb Daniel Vetter:
> > > > > > Random observation while trying to review Christian's patch series
> > > > > > to
> > > > > > stop looking at struct page for dma-buf imports.
> > > > > >
> > > > > > This was originally added in
> > > > > >
> > > > > > commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
> > > > > > Author: Thomas Hellstrom
> > > > > > Date: Fri Jan 3 11:47:23 2014 +0100
> > > > > >
> > > > > >drm/ttm: Correctly set page mapping and -index members
> > > > > >
> > > > > >Needed for some vm operations; most notably
> > > > > > unmap_mapping_range() with
> > > > > >even_cows = 0.
> > > > > >
> > > > > >Signed-off-by: Thomas Hellstrom
> > > > > >Reviewed-by: Brian Paul
> > > > > >
> > > > > > but we do not have a single caller of unmap_mapping_range with
> > > > > > even_cows == 0. And all the gem drivers don't do this, so another
> > > > > > small thing we could standardize between drm and ttm drivers.
> > > > > >
> > > > > > Plus I don't really see a need for unamp_mapping_range where we
> > > > > > don't
> > > > > > want to indiscriminately shoot down all ptes.
> > > > > NAK, we use this to determine if a pages belongs to the driver or not
> > > > > in
> > > > > amdgpu for example.
> > > > >
> > > > > Mostly used for debugging, but I would really like to keep that.
> > > > Can you pls point me at that code? A quick grep hasn't really found
> > > > much at all.
> > > See amdgpu_iomem_read() for an example:
> > Why do you reject this?
>
> When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise give the
> same access as /dev/mem to system memory and that is forbidden. But as I
> noted this is just for the debugfs file.
Ah, there's a config option for that. Plus it's debugfs, anything goes in
debugfs, but if you're worried about that hole we should just disable the
entire debugfs file for CONFIG_STRICT_DEVMEM. I can perhaps throw that on
top, that follow_pfn patch series I'm baking is all about this kind of
fun.
> When I tried a few years ago to not set the page->mapping I immediately ran
> into issues with our eviction test. So I think that this is used elsewhere
> as well.
That's the kind of interaction I'm worried about here tbh. If this does
some kind of shrinking of some sorts, I think a real shrinker should take
over.
An improved grep shows nothing else, so the only the above is the only
thing I can think of. What kind of eviction test goes boom if you clear
->mapping here? I'd be happy to type up the clever trick for the debugfs
files.
-Daniel
>
> Regards,
> Christian.
>
> >
> > If this is to avoid issues with userptr, then I think there's a simple
> > trick:
> > - grab page reference
> > - recheck that the iova still points at the same address
> > - do read/write, safe in the knowledge that this page cannot be reused for
> >anything else
> > - drop page reference
> >
> > Of course this can still race against iova updates, but that seems to be a
> > fundamental part of your debug interface here.
> >
> > Or am I missing something?
> >
> > Just pondering this more since setting the page->mapping pointer for just
> > this seems somewhat wild abuse of ->mapping semantics :-)
> > -Daniel
> >
> > > > if (p->mapping != adev->mman.bdev.dev_mapping)
> > > > return -EPERM;
> > > Christian.
> > >
> > > > -Daniel
> > > >
> > > > > Christian.
> > > > >
> > > > > > Cc: Thomas Hellstrom
> > > > > > Cc: Brian Paul
> > > > > > Signed-off-by: Daniel Vetter
> > > > > > Cc: Christian Koenig
> > > > > > Cc: Huang Rui
> > > > > > ---
> > > > > > drivers/gpu/drm/ttm/ttm_tt.c | 12
> > > > > > 1 file changed, 12 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/gpu/drm/ttm/ttm_tt.c
> > > > > > b/drivers/gpu/drm/ttm/ttm_tt.c
> > > > > > index 8861a74ac335..438ea43fd8c1 100644
> > > > > > --- a/drivers/gpu/drm/ttm/ttm_tt.c
> > > > > > +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> > > > > > @@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev,
> > > > > > struct ttm_tt *ttm)
> > > > > > return ret;
> > > > > > }
> > > > > >
> > > > > > -static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct
> > > > > > ttm_tt *ttm)
> > > > > > -{
> > > > > > - pgoff_t i;
> > > > > > -
> > > > > > - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> > > > > > - return;
> > > > > > -
> > > > > > - for (i = 0; i < ttm->num_pages; ++i)
> > > > > > - ttm->pages[i]->mapping = bdev->dev_mapping;
> > > > > > -}
> > > > > > -
> > > > > > int ttm_tt_populate(struct ttm_bo_device *bdev,
> > >
Re: [PATCH] drm/ttm: don't set page->mapping
Am 05.11.20 um 13:50 schrieb Daniel Vetter:
On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote:
Am 05.11.20 um 10:11 schrieb Daniel Vetter:
On Thu, Nov 5, 2020 at 9:00 AM Christian König wrote:
Am 04.11.20 um 17:50 schrieb Daniel Vetter:
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
NAK, we use this to determine if a pages belongs to the driver or not in
amdgpu for example.
Mostly used for debugging, but I would really like to keep that.
Can you pls point me at that code? A quick grep hasn't really found much at all.
See amdgpu_iomem_read() for an example:
Why do you reject this?
When IOMMU is disabled or uses an 1 to 1 mapping we would otherwise give
the same access as /dev/mem to system memory and that is forbidden. But
as I noted this is just for the debugfs file.
When I tried a few years ago to not set the page->mapping I immediately
ran into issues with our eviction test. So I think that this is used
elsewhere as well.
Regards,
Christian.
If this is to avoid issues with userptr, then I think there's a simple
trick:
- grab page reference
- recheck that the iova still points at the same address
- do read/write, safe in the knowledge that this page cannot be reused for
anything else
- drop page reference
Of course this can still race against iova updates, but that seems to be a
fundamental part of your debug interface here.
Or am I missing something?
Just pondering this more since setting the page->mapping pointer for just
this seems somewhat wild abuse of ->mapping semantics :-)
-Daniel
if (p->mapping != adev->mman.bdev.dev_mapping)
return -EPERM;
Christian.
-Daniel
Christian.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 8861a74ac335..438ea43fd8c1 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -320,7 +309,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
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Re: [PATCH] drm/ttm: don't set page->mapping
On Thu, Nov 05, 2020 at 01:29:50PM +0100, Christian König wrote:
> Am 05.11.20 um 10:11 schrieb Daniel Vetter:
> > On Thu, Nov 5, 2020 at 9:00 AM Christian König
> > wrote:
> > > Am 04.11.20 um 17:50 schrieb Daniel Vetter:
> > > > Random observation while trying to review Christian's patch series to
> > > > stop looking at struct page for dma-buf imports.
> > > >
> > > > This was originally added in
> > > >
> > > > commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
> > > > Author: Thomas Hellstrom
> > > > Date: Fri Jan 3 11:47:23 2014 +0100
> > > >
> > > > drm/ttm: Correctly set page mapping and -index members
> > > >
> > > > Needed for some vm operations; most notably unmap_mapping_range()
> > > > with
> > > > even_cows = 0.
> > > >
> > > > Signed-off-by: Thomas Hellstrom
> > > > Reviewed-by: Brian Paul
> > > >
> > > > but we do not have a single caller of unmap_mapping_range with
> > > > even_cows == 0. And all the gem drivers don't do this, so another
> > > > small thing we could standardize between drm and ttm drivers.
> > > >
> > > > Plus I don't really see a need for unamp_mapping_range where we don't
> > > > want to indiscriminately shoot down all ptes.
> > > NAK, we use this to determine if a pages belongs to the driver or not in
> > > amdgpu for example.
> > >
> > > Mostly used for debugging, but I would really like to keep that.
> > Can you pls point me at that code? A quick grep hasn't really found much at
> > all.
>
> See amdgpu_iomem_read() for an example:
Why do you reject this?
If this is to avoid issues with userptr, then I think there's a simple
trick:
- grab page reference
- recheck that the iova still points at the same address
- do read/write, safe in the knowledge that this page cannot be reused for
anything else
- drop page reference
Of course this can still race against iova updates, but that seems to be a
fundamental part of your debug interface here.
Or am I missing something?
Just pondering this more since setting the page->mapping pointer for just
this seems somewhat wild abuse of ->mapping semantics :-)
-Daniel
>
> > if (p->mapping != adev->mman.bdev.dev_mapping)
> > return -EPERM;
>
> Christian.
>
> > -Daniel
> >
> > > Christian.
> > >
> > > > Cc: Thomas Hellstrom
> > > > Cc: Brian Paul
> > > > Signed-off-by: Daniel Vetter
> > > > Cc: Christian Koenig
> > > > Cc: Huang Rui
> > > > ---
> > > >drivers/gpu/drm/ttm/ttm_tt.c | 12
> > > >1 file changed, 12 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> > > > index 8861a74ac335..438ea43fd8c1 100644
> > > > --- a/drivers/gpu/drm/ttm/ttm_tt.c
> > > > +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> > > > @@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev,
> > > > struct ttm_tt *ttm)
> > > >return ret;
> > > >}
> > > >
> > > > -static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct
> > > > ttm_tt *ttm)
> > > > -{
> > > > - pgoff_t i;
> > > > -
> > > > - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> > > > - return;
> > > > -
> > > > - for (i = 0; i < ttm->num_pages; ++i)
> > > > - ttm->pages[i]->mapping = bdev->dev_mapping;
> > > > -}
> > > > -
> > > >int ttm_tt_populate(struct ttm_bo_device *bdev,
> > > >struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
> > > >{
> > > > @@ -320,7 +309,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
> > > >if (ret)
> > > >return ret;
> > > >
> > > > - ttm_tt_add_mapping(bdev, ttm);
> > > >ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
> > > >if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
> > > >ret = ttm_tt_swapin(ttm);
> >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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Re: [PATCH] drm/ttm: don't set page->mapping
Am 05.11.20 um 10:11 schrieb Daniel Vetter:
On Thu, Nov 5, 2020 at 9:00 AM Christian König wrote:
Am 04.11.20 um 17:50 schrieb Daniel Vetter:
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
NAK, we use this to determine if a pages belongs to the driver or not in
amdgpu for example.
Mostly used for debugging, but I would really like to keep that.
Can you pls point me at that code? A quick grep hasn't really found much at all.
See amdgpu_iomem_read() for an example:
if (p->mapping != adev->mman.bdev.dev_mapping)
return -EPERM;
Christian.
-Daniel
Christian.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 8861a74ac335..438ea43fd8c1 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -320,7 +309,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
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Re: [PATCH] drm/ttm: don't set page->mapping
On Thu, Nov 5, 2020 at 9:00 AM Christian König wrote:
>
> Am 04.11.20 um 17:50 schrieb Daniel Vetter:
> > Random observation while trying to review Christian's patch series to
> > stop looking at struct page for dma-buf imports.
> >
> > This was originally added in
> >
> > commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
> > Author: Thomas Hellstrom
> > Date: Fri Jan 3 11:47:23 2014 +0100
> >
> > drm/ttm: Correctly set page mapping and -index members
> >
> > Needed for some vm operations; most notably unmap_mapping_range() with
> > even_cows = 0.
> >
> > Signed-off-by: Thomas Hellstrom
> > Reviewed-by: Brian Paul
> >
> > but we do not have a single caller of unmap_mapping_range with
> > even_cows == 0. And all the gem drivers don't do this, so another
> > small thing we could standardize between drm and ttm drivers.
> >
> > Plus I don't really see a need for unamp_mapping_range where we don't
> > want to indiscriminately shoot down all ptes.
>
> NAK, we use this to determine if a pages belongs to the driver or not in
> amdgpu for example.
>
> Mostly used for debugging, but I would really like to keep that.
Can you pls point me at that code? A quick grep hasn't really found much at all.
-Daniel
>
> Christian.
>
> >
> > Cc: Thomas Hellstrom
> > Cc: Brian Paul
> > Signed-off-by: Daniel Vetter
> > Cc: Christian Koenig
> > Cc: Huang Rui
> > ---
> > drivers/gpu/drm/ttm/ttm_tt.c | 12
> > 1 file changed, 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> > index 8861a74ac335..438ea43fd8c1 100644
> > --- a/drivers/gpu/drm/ttm/ttm_tt.c
> > +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> > @@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
> > ttm_tt *ttm)
> > return ret;
> > }
> >
> > -static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt
> > *ttm)
> > -{
> > - pgoff_t i;
> > -
> > - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> > - return;
> > -
> > - for (i = 0; i < ttm->num_pages; ++i)
> > - ttm->pages[i]->mapping = bdev->dev_mapping;
> > -}
> > -
> > int ttm_tt_populate(struct ttm_bo_device *bdev,
> > struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
> > {
> > @@ -320,7 +309,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
> > if (ret)
> > return ret;
> >
> > - ttm_tt_add_mapping(bdev, ttm);
> > ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
> > if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
> > ret = ttm_tt_swapin(ttm);
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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Re: [PATCH] drm/ttm: don't set page->mapping
Am 04.11.20 um 17:50 schrieb Daniel Vetter:
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
NAK, we use this to determine if a pages belongs to the driver or not in
amdgpu for example.
Mostly used for debugging, but I would really like to keep that.
Christian.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 8861a74ac335..438ea43fd8c1 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -320,7 +309,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
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[PATCH] drm/ttm: don't set page->mapping
Random observation while trying to review Christian's patch series to
stop looking at struct page for dma-buf imports.
This was originally added in
commit 58aa6622d32af7d2c08d45085f44c54554a16ed7
Author: Thomas Hellstrom
Date: Fri Jan 3 11:47:23 2014 +0100
drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.
Signed-off-by: Thomas Hellstrom
Reviewed-by: Brian Paul
but we do not have a single caller of unmap_mapping_range with
even_cows == 0. And all the gem drivers don't do this, so another
small thing we could standardize between drm and ttm drivers.
Plus I don't really see a need for unamp_mapping_range where we don't
want to indiscriminately shoot down all ptes.
Cc: Thomas Hellstrom
Cc: Brian Paul
Signed-off-by: Daniel Vetter
Cc: Christian Koenig
Cc: Huang Rui
---
drivers/gpu/drm/ttm/ttm_tt.c | 12
1 file changed, 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 8861a74ac335..438ea43fd8c1 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -291,17 +291,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct
ttm_tt *ttm)
return ret;
}
-static void ttm_tt_add_mapping(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
-{
- pgoff_t i;
-
- if (ttm->page_flags & TTM_PAGE_FLAG_SG)
- return;
-
- for (i = 0; i < ttm->num_pages; ++i)
- ttm->pages[i]->mapping = bdev->dev_mapping;
-}
-
int ttm_tt_populate(struct ttm_bo_device *bdev,
struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
@@ -320,7 +309,6 @@ int ttm_tt_populate(struct ttm_bo_device *bdev,
if (ret)
return ret;
- ttm_tt_add_mapping(bdev, ttm);
ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
--
2.28.0
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