[PATCH] drm/radeon: fix AGP userptr handling

[Alex Deucher]

On Wed, Sep 17, 2014 at 6:00 AM, Christian König
<deathsimple at vodafone.de> wrote:
> From: Christian König <christian.koenig at amd.com>
>
> AGP mappings are not cache coherent, so userptr support
> won't work. Additional to that the AGP implementation uses
> a different ttm_tt container structure so we run into
> problems if we cast the pointer without checking if it's
> the right type.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>

Applied to my 3.18 tree.  thanks!

Alex

> ---
>  drivers/gpu/drm/radeon/radeon_ttm.c | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
> index eca2ce6..d73ea9c 100644
> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> @@ -675,10 +675,17 @@ static struct ttm_tt *radeon_ttm_tt_create(struct ttm_bo_device *bdev,
>         return &gtt->ttm.ttm;
>  }
>
> +static struct radeon_ttm_tt *radeon_ttm_tt_to_gtt(struct ttm_tt *ttm)
> +{
> +       if (!ttm || ttm->func != &radeon_backend_func)
> +               return NULL;
> +       return (struct radeon_ttm_tt *)ttm;
> +}
> +
>  static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
>  {
> +       struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);
>         struct radeon_device *rdev;
> -       struct radeon_ttm_tt *gtt = (void *)ttm;
>         unsigned i;
>         int r;
>         bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
> @@ -686,7 +693,7 @@ static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
>         if (ttm->state != tt_unpopulated)
>                 return 0;
>
> -       if (gtt->userptr) {
> +       if (gtt && gtt->userptr) {
>                 ttm->sg = kcalloc(1, sizeof(struct sg_table), GFP_KERNEL);
>                 if (!ttm->sg)
>                         return -ENOMEM;
> @@ -741,11 +748,11 @@ static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
>  static void radeon_ttm_tt_unpopulate(struct ttm_tt *ttm)
>  {
>         struct radeon_device *rdev;
> -       struct radeon_ttm_tt *gtt = (void *)ttm;
> +       struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);
>         unsigned i;
>         bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
>
> -       if (gtt->userptr) {
> +       if (gtt && gtt->userptr) {
>                 kfree(ttm->sg);
>                 ttm->page_flags &= ~TTM_PAGE_FLAG_SG;
>                 return;
> @@ -782,7 +789,7 @@ static void radeon_ttm_tt_unpopulate(struct ttm_tt *ttm)
>  int radeon_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
>                               uint32_t flags)
>  {
> -       struct radeon_ttm_tt *gtt = (void *)ttm;
> +       struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);
>
>         if (gtt == NULL)
>                 return -EINVAL;
> @@ -795,7 +802,7 @@ int radeon_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
>
>  bool radeon_ttm_tt_has_userptr(struct ttm_tt *ttm)
>  {
> -       struct radeon_ttm_tt *gtt = (void *)ttm;
> +       struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);
>
>         if (gtt == NULL)
>                 return false;
> @@ -805,7 +812,7 @@ bool radeon_ttm_tt_has_userptr(struct ttm_tt *ttm)
>
>  bool radeon_ttm_tt_is_readonly(struct ttm_tt *ttm)
>  {
> -       struct radeon_ttm_tt *gtt = (void *)ttm;
> +       struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);
>
>         if (gtt == NULL)
>                 return false;
> --
> 1.8.3.2
>