[PATCH 2/2] drm/radeon: add user pointer support v3

Alex Deucher alexdeucher at gmail.com
Thu Jul 10 06:48:49 PDT 2014


On Thu, Jul 10, 2014 at 8:33 AM, Christian König
<deathsimple at vodafone.de> wrote:
> From: Christian König <christian.koenig at amd.com>
>
> This patch adds an IOCTL for turning a pointer supplied by
> userspace into a buffer object.
>
> It imposes several restrictions upon the memory being mapped:
>
> 1. It must be page aligned (both start/end addresses, i.e ptr and size).
>
> 2. It must be normal system memory, not a pointer into another map of IO
> space (e.g. it must not be a GTT mmapping of another object).
>
> 3. The BO is mapped into GTT, so the maximum amount of memory mapped at
> all times is still the GTT limit.
>
> 4. The BO is only mapped readonly for now, so no write support.
>
> 5. List of backing pages is only acquired once, so they represent a
> snapshot of the first use.
>
> Exporting and sharing as well as mapping of buffer objects created by
> this function is forbidden and results in an -EPERM.
>
> v2: squash all previous changes into first public version
> v3: fix tabs, map readonly, don't use MM callback any more
>
> Signed-off-by: Christian König <christian.koenig at amd.com>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  drivers/gpu/drm/radeon/radeon.h        |   4 ++
>  drivers/gpu/drm/radeon/radeon_cs.c     |  25 +++++++-
>  drivers/gpu/drm/radeon/radeon_drv.c    |   5 +-
>  drivers/gpu/drm/radeon/radeon_gem.c    |  67 +++++++++++++++++++++
>  drivers/gpu/drm/radeon/radeon_kms.c    |   1 +
>  drivers/gpu/drm/radeon/radeon_object.c |   3 +
>  drivers/gpu/drm/radeon/radeon_prime.c  |  10 +++
>  drivers/gpu/drm/radeon/radeon_ttm.c    | 107 ++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/radeon/radeon_vm.c     |   3 +
>  include/uapi/drm/radeon_drm.h          |  11 ++++
>  10 files changed, 232 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> index 86fdfa30..55c996e 100644
> --- a/drivers/gpu/drm/radeon/radeon.h
> +++ b/drivers/gpu/drm/radeon/radeon.h
> @@ -2111,6 +2111,8 @@ int radeon_gem_info_ioctl(struct drm_device *dev, void *data,
>                           struct drm_file *filp);
>  int radeon_gem_create_ioctl(struct drm_device *dev, void *data,
>                             struct drm_file *filp);
> +int radeon_gem_import_ioctl(struct drm_device *dev, void *data,
> +                           struct drm_file *filp);
>  int radeon_gem_pin_ioctl(struct drm_device *dev, void *data,
>                          struct drm_file *file_priv);
>  int radeon_gem_unpin_ioctl(struct drm_device *dev, void *data,
> @@ -2803,6 +2805,8 @@ extern void radeon_legacy_set_clock_gating(struct radeon_device *rdev, int enabl
>  extern void radeon_atom_set_clock_gating(struct radeon_device *rdev, int enable);
>  extern void radeon_ttm_placement_from_domain(struct radeon_bo *rbo, u32 domain);
>  extern bool radeon_ttm_bo_is_radeon_bo(struct ttm_buffer_object *bo);
> +extern int radeon_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t userptr);
> +extern bool radeon_ttm_tt_has_userptr(struct ttm_tt *ttm);
>  extern void radeon_vram_location(struct radeon_device *rdev, struct radeon_mc *mc, u64 base);
>  extern void radeon_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc);
>  extern int radeon_resume_kms(struct drm_device *dev, bool resume, bool fbcon);
> diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
> index 71a1434..be65311 100644
> --- a/drivers/gpu/drm/radeon/radeon_cs.c
> +++ b/drivers/gpu/drm/radeon/radeon_cs.c
> @@ -78,7 +78,8 @@ static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
>         struct radeon_cs_chunk *chunk;
>         struct radeon_cs_buckets buckets;
>         unsigned i, j;
> -       bool duplicate;
> +       bool duplicate, need_mmap_lock = false;
> +       int r;
>
>         if (p->chunk_relocs_idx == -1) {
>                 return 0;
> @@ -164,6 +165,19 @@ static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
>                         p->relocs[i].allowed_domains = domain;
>                 }
>
> +               if (radeon_ttm_tt_has_userptr(p->relocs[i].robj->tbo.ttm)) {
> +                       uint32_t domain = p->relocs[i].prefered_domains;
> +                       if (!(domain & RADEON_GEM_DOMAIN_GTT)) {
> +                               DRM_ERROR("Only RADEON_GEM_DOMAIN_GTT is "
> +                                         "allowed for userptr BOs\n");
> +                               return -EINVAL;
> +                       }
> +                       need_mmap_lock = true;
> +                       domain = RADEON_GEM_DOMAIN_GTT;
> +                       p->relocs[i].prefered_domains = domain;
> +                       p->relocs[i].allowed_domains = domain;
> +               }
> +
>                 p->relocs[i].tv.bo = &p->relocs[i].robj->tbo;
>                 p->relocs[i].handle = r->handle;
>
> @@ -176,8 +190,15 @@ static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
>         if (p->cs_flags & RADEON_CS_USE_VM)
>                 p->vm_bos = radeon_vm_get_bos(p->rdev, p->ib.vm,
>                                               &p->validated);
> +       if (need_mmap_lock)
> +               down_read(&current->mm->mmap_sem);
> +
> +       r = radeon_bo_list_validate(p->rdev, &p->ticket, &p->validated, p->ring);
>
> -       return radeon_bo_list_validate(p->rdev, &p->ticket, &p->validated, p->ring);
> +       if (need_mmap_lock)
> +               up_read(&current->mm->mmap_sem);
> +
> +       return r;
>  }
>
>  static int radeon_cs_get_ring(struct radeon_cs_parser *p, u32 ring, s32 priority)
> diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
> index cb14213..bf91879 100644
> --- a/drivers/gpu/drm/radeon/radeon_drv.c
> +++ b/drivers/gpu/drm/radeon/radeon_drv.c
> @@ -112,6 +112,9 @@ int radeon_gem_object_open(struct drm_gem_object *obj,
>                                 struct drm_file *file_priv);
>  void radeon_gem_object_close(struct drm_gem_object *obj,
>                                 struct drm_file *file_priv);
> +struct dma_buf *radeon_gem_prime_export(struct drm_device *dev,
> +                                       struct drm_gem_object *gobj,
> +                                       int flags);
>  extern int radeon_get_crtc_scanoutpos(struct drm_device *dev, int crtc,
>                                       unsigned int flags,
>                                       int *vpos, int *hpos, ktime_t *stime,
> @@ -562,7 +565,7 @@ static struct drm_driver kms_driver = {
>
>         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
>         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> -       .gem_prime_export = drm_gem_prime_export,
> +       .gem_prime_export = radeon_gem_prime_export,
>         .gem_prime_import = drm_gem_prime_import,
>         .gem_prime_pin = radeon_gem_prime_pin,
>         .gem_prime_unpin = radeon_gem_prime_unpin,
> diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
> index d09650c..2464c65 100644
> --- a/drivers/gpu/drm/radeon/radeon_gem.c
> +++ b/drivers/gpu/drm/radeon/radeon_gem.c
> @@ -272,6 +272,64 @@ int radeon_gem_create_ioctl(struct drm_device *dev, void *data,
>         return 0;
>  }
>
> +int radeon_gem_import_ioctl(struct drm_device *dev, void *data,
> +                           struct drm_file *filp)
> +{
> +       struct radeon_device *rdev = dev->dev_private;
> +       struct drm_radeon_gem_import *args = data;
> +       struct drm_gem_object *gobj;
> +       struct radeon_bo *bo;
> +       uint32_t handle;
> +       int r;
> +
> +       if (offset_in_page(args->addr | args->size))
> +               return -EINVAL;
> +
> +       /* we only support read only mappings for now */
> +       if (!(args->flags & RADEON_GEM_IMPORT_READONLY))
> +               return -EACCES;
> +
> +       /* readonly pages not tested on older hardware */
> +       if (rdev->family < CHIP_R600)
> +               return -EINVAL;
> +
> +       if (!access_ok(VERIFY_READ, (char __user *)args->addr, args->size))
> +               return -EFAULT;
> +
> +       down_read(&rdev->exclusive_lock);
> +
> +       /* create a gem object to contain this object in */
> +       r = radeon_gem_object_create(rdev, args->size, 0,
> +                                    RADEON_GEM_DOMAIN_CPU,
> +                                    false, false, &gobj);
> +       if (r)
> +               goto handle_lockup;
> +
> +       bo = gem_to_radeon_bo(gobj);
> +       r = radeon_ttm_tt_set_userptr(bo->tbo.ttm, args->addr);
> +       if (r)
> +               goto release_object;
> +
> +       r = drm_gem_handle_create(filp, gobj, &handle);
> +       /* drop reference from allocate - handle holds it now */
> +       drm_gem_object_unreference_unlocked(gobj);
> +       if (r)
> +               goto handle_lockup;
> +
> +       args->handle = handle;
> +       up_read(&rdev->exclusive_lock);
> +       return 0;
> +
> +release_object:
> +       drm_gem_object_unreference_unlocked(gobj);
> +
> +handle_lockup:
> +       up_read(&rdev->exclusive_lock);
> +       r = radeon_gem_handle_lockup(rdev, r);
> +
> +       return r;
> +}
> +
>  int radeon_gem_set_domain_ioctl(struct drm_device *dev, void *data,
>                                 struct drm_file *filp)
>  {
> @@ -315,6 +373,10 @@ int radeon_mode_dumb_mmap(struct drm_file *filp,
>                 return -ENOENT;
>         }
>         robj = gem_to_radeon_bo(gobj);
> +       if (radeon_ttm_tt_has_userptr(robj->tbo.ttm)) {
> +               drm_gem_object_unreference_unlocked(gobj);
> +               return -EPERM;
> +       }
>         *offset_p = radeon_bo_mmap_offset(robj);
>         drm_gem_object_unreference_unlocked(gobj);
>         return 0;
> @@ -535,6 +597,11 @@ int radeon_gem_op_ioctl(struct drm_device *dev, void *data,
>                 return -ENOENT;
>         }
>         robj = gem_to_radeon_bo(gobj);
> +
> +       r = -EPERM;
> +       if (radeon_ttm_tt_has_userptr(robj->tbo.ttm))
> +               goto out;
> +
>         r = radeon_bo_reserve(robj, false);
>         if (unlikely(r))
>                 goto out;
> diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
> index 35d9318..39e8a5c 100644
> --- a/drivers/gpu/drm/radeon/radeon_kms.c
> +++ b/drivers/gpu/drm/radeon/radeon_kms.c
> @@ -874,5 +874,6 @@ const struct drm_ioctl_desc radeon_ioctls_kms[] = {
>         DRM_IOCTL_DEF_DRV(RADEON_GEM_BUSY, radeon_gem_busy_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
>         DRM_IOCTL_DEF_DRV(RADEON_GEM_VA, radeon_gem_va_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
>         DRM_IOCTL_DEF_DRV(RADEON_GEM_OP, radeon_gem_op_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
> +       DRM_IOCTL_DEF_DRV(RADEON_GEM_IMPORT, radeon_gem_import_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
>  };
>  int radeon_max_kms_ioctl = ARRAY_SIZE(radeon_ioctls_kms);
> diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
> index 6c717b2..c1f826b 100644
> --- a/drivers/gpu/drm/radeon/radeon_object.c
> +++ b/drivers/gpu/drm/radeon/radeon_object.c
> @@ -253,6 +253,9 @@ int radeon_bo_pin_restricted(struct radeon_bo *bo, u32 domain, u64 max_offset,
>  {
>         int r, i;
>
> +       if (radeon_ttm_tt_has_userptr(bo->tbo.ttm))
> +               return -EPERM;
> +
>         if (bo->pin_count) {
>                 bo->pin_count++;
>                 if (gpu_addr)
> diff --git a/drivers/gpu/drm/radeon/radeon_prime.c b/drivers/gpu/drm/radeon/radeon_prime.c
> index 2007456..1f0d8f7 100644
> --- a/drivers/gpu/drm/radeon/radeon_prime.c
> +++ b/drivers/gpu/drm/radeon/radeon_prime.c
> @@ -103,3 +103,13 @@ void radeon_gem_prime_unpin(struct drm_gem_object *obj)
>         radeon_bo_unpin(bo);
>         radeon_bo_unreserve(bo);
>  }
> +
> +struct dma_buf *radeon_gem_prime_export(struct drm_device *dev,
> +                                       struct drm_gem_object *gobj,
> +                                       int flags)
> +{
> +       struct radeon_bo *bo = gem_to_radeon_bo(gobj);
> +       if (radeon_ttm_tt_has_userptr(bo->tbo.ttm))
> +               return ERR_PTR(-EPERM);
> +       return drm_gem_prime_export(dev, gobj, flags);
> +}
> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
> index 19d662f..fee6018 100644
> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> @@ -515,12 +515,16 @@ struct radeon_ttm_tt {
>         struct ttm_dma_tt               ttm;
>         struct radeon_device            *rdev;
>         u64                             offset;
> +
> +       uint64_t                        userptr;
> +       struct mm_struct                *usermm;
>  };
>
>  static int radeon_ttm_backend_bind(struct ttm_tt *ttm,
>                                    struct ttm_mem_reg *bo_mem)
>  {
>         struct radeon_ttm_tt *gtt = (void*)ttm;
> +       uint32_t flags = gtt->userptr ? RADEON_GART_PAGE_READONLY : 0;
>         int r;
>
>         gtt->offset = (unsigned long)(bo_mem->start << PAGE_SHIFT);
> @@ -529,7 +533,7 @@ static int radeon_ttm_backend_bind(struct ttm_tt *ttm,
>                      ttm->num_pages, bo_mem, ttm);
>         }
>         r = radeon_gart_bind(gtt->rdev, gtt->offset, ttm->num_pages,
> -                            ttm->pages, gtt->ttm.dma_address, 0);
> +                            ttm->pages, gtt->ttm.dma_address, flags);
>         if (r) {
>                 DRM_ERROR("failed to bind %lu pages at 0x%08X\n",
>                           ttm->num_pages, (unsigned)gtt->offset);
> @@ -588,6 +592,73 @@ static struct ttm_tt *radeon_ttm_tt_create(struct ttm_bo_device *bdev,
>         return &gtt->ttm.ttm;
>  }
>
> +static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
> +{
> +       struct radeon_device *rdev = radeon_get_rdev(ttm->bdev);
> +       struct radeon_ttm_tt *gtt = (void *)ttm;
> +       unsigned pinned = 0, nents;
> +       int r;
> +
> +       /* prepare the sg table with the user pages */
> +       if (current->mm != gtt->usermm)
> +               return -EPERM;
> +
> +       do {
> +               unsigned num_pages = ttm->num_pages - pinned;
> +               uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
> +               struct page **pages = ttm->pages + pinned;
> +
> +               r = get_user_pages(current, current->mm, userptr, num_pages,
> +                                  0, 0, pages, NULL);
> +               if (r < 0) {
> +                       release_pages(ttm->pages, pinned, 0);
> +                       return r;
> +               }
> +               pinned += r;
> +
> +       } while (pinned < ttm->num_pages);
> +
> +       r = -ENOMEM;
> +       ttm->sg = kcalloc(1, sizeof(struct sg_table), GFP_KERNEL);
> +       if (!ttm->sg)
> +               goto release_pages;
> +
> +       r = sg_alloc_table_from_pages(ttm->sg, ttm->pages, ttm->num_pages, 0,
> +                                     ttm->num_pages << PAGE_SHIFT,
> +                                     GFP_KERNEL);
> +       if (r)
> +               goto release_sg;
> +
> +       r = -ENOMEM;
> +       nents = dma_map_sg(rdev->dev, ttm->sg->sgl, ttm->sg->nents,
> +                          DMA_TO_DEVICE);
> +       if (nents != ttm->sg->nents)
> +               goto release_sg;
> +
> +       return 0;
> +
> +release_sg:
> +       kfree(ttm->sg);
> +
> +release_pages:
> +       release_pages(ttm->pages, pinned, 0);
> +       return r;
> +}
> +
> +static void radeon_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
> +{
> +       struct radeon_device *rdev = radeon_get_rdev(ttm->bdev);
> +
> +       /* free the sg table and pages again */
> +       dma_unmap_sg(rdev->dev, ttm->sg->sgl,
> +                    ttm->sg->nents, DMA_TO_DEVICE);
> +
> +       sg_free_table(ttm->sg);
> +       kfree(ttm->sg);
> +
> +       release_pages(ttm->pages, ttm->num_pages, 0);
> +}
> +
>  static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
>  {
>         struct radeon_device *rdev;
> @@ -599,6 +670,13 @@ static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
>         if (ttm->state != tt_unpopulated)
>                 return 0;
>
> +       if (gtt->userptr) {
> +               r = radeon_ttm_tt_pin_userptr(ttm);
> +               if (r)
> +                       return r;
> +               slave = true;
> +       }
> +
>         if (slave && ttm->sg) {
>                 drm_prime_sg_to_page_addr_arrays(ttm->sg, ttm->pages,
>                                                  gtt->ttm.dma_address, ttm->num_pages);
> @@ -648,6 +726,11 @@ static void radeon_ttm_tt_unpopulate(struct ttm_tt *ttm)
>         unsigned i;
>         bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
>
> +       if (gtt->userptr) {
> +               radeon_ttm_tt_unpin_userptr(ttm);
> +               return;
> +       }
> +
>         if (slave)
>                 return;
>
> @@ -676,6 +759,28 @@ static void radeon_ttm_tt_unpopulate(struct ttm_tt *ttm)
>         ttm_pool_unpopulate(ttm);
>  }
>
> +int radeon_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t userptr)
> +{
> +       struct radeon_ttm_tt *gtt = (void *)ttm;
> +
> +       if (gtt == NULL)
> +               return -EINVAL;
> +
> +       gtt->userptr = userptr;
> +       gtt->usermm = current->mm;
> +       return 0;
> +}
> +
> +bool radeon_ttm_tt_has_userptr(struct ttm_tt *ttm)
> +{
> +       struct radeon_ttm_tt *gtt = (void *)ttm;
> +
> +       if (gtt == NULL)
> +               return false;
> +
> +       return !!gtt->userptr;
> +}
> +
>  static struct ttm_bo_driver radeon_bo_driver = {
>         .ttm_tt_create = &radeon_ttm_tt_create,
>         .ttm_tt_populate = &radeon_ttm_tt_populate,
> diff --git a/drivers/gpu/drm/radeon/radeon_vm.c b/drivers/gpu/drm/radeon/radeon_vm.c
> index eecff6b..99663a8 100644
> --- a/drivers/gpu/drm/radeon/radeon_vm.c
> +++ b/drivers/gpu/drm/radeon/radeon_vm.c
> @@ -850,6 +850,9 @@ int radeon_vm_bo_update(struct radeon_device *rdev,
>
>         bo_va->flags &= ~RADEON_VM_PAGE_VALID;
>         bo_va->flags &= ~RADEON_VM_PAGE_SYSTEM;
> +       if (radeon_ttm_tt_has_userptr(bo->tbo.ttm))
> +               bo_va->flags &= ~RADEON_VM_PAGE_WRITEABLE;
> +
>         if (mem) {
>                 addr = mem->start << PAGE_SHIFT;
>                 if (mem->mem_type != TTM_PL_SYSTEM) {
> diff --git a/include/uapi/drm/radeon_drm.h b/include/uapi/drm/radeon_drm.h
> index 1cc0b61..64ef99c 100644
> --- a/include/uapi/drm/radeon_drm.h
> +++ b/include/uapi/drm/radeon_drm.h
> @@ -511,6 +511,7 @@ typedef struct {
>  #define DRM_RADEON_GEM_BUSY            0x2a
>  #define DRM_RADEON_GEM_VA              0x2b
>  #define DRM_RADEON_GEM_OP              0x2c
> +#define DRM_RADEON_GEM_IMPORT          0x2d
>
>  #define DRM_IOCTL_RADEON_CP_INIT    DRM_IOW( DRM_COMMAND_BASE + DRM_RADEON_CP_INIT, drm_radeon_init_t)
>  #define DRM_IOCTL_RADEON_CP_START   DRM_IO(  DRM_COMMAND_BASE + DRM_RADEON_CP_START)
> @@ -554,6 +555,7 @@ typedef struct {
>  #define DRM_IOCTL_RADEON_GEM_BUSY      DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_BUSY, struct drm_radeon_gem_busy)
>  #define DRM_IOCTL_RADEON_GEM_VA                DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_VA, struct drm_radeon_gem_va)
>  #define DRM_IOCTL_RADEON_GEM_OP                DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_OP, struct drm_radeon_gem_op)
> +#define DRM_IOCTL_RADEON_GEM_IMPORT    DRM_IOWR(DRM_COMMAND_BASE + DRM_RADEON_GEM_IMPORT, struct drm_radeon_gem_import)
>
>  typedef struct drm_radeon_init {
>         enum {
> @@ -806,6 +808,15 @@ struct drm_radeon_gem_create {
>         uint32_t        flags;
>  };
>
> +#define RADEON_GEM_IMPORT_READONLY     0x1
> +
> +struct drm_radeon_gem_import {
> +       uint64_t                addr;
> +       uint64_t                size;
> +       uint32_t                flags;
> +       uint32_t                handle;
> +};
> +
>  #define RADEON_TILING_MACRO                            0x1
>  #define RADEON_TILING_MICRO                            0x2
>  #define RADEON_TILING_SWAP_16BIT                       0x4
> --
> 1.9.1
>
> _______________________________________________
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> dri-devel at lists.freedesktop.org
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