diff options
| -rw-r--r-- | linux-core/drm_bo.c | 43 | ||||
| -rw-r--r-- | linux-core/drm_objects.h | 26 |
2 files changed, 62 insertions, 7 deletions
diff --git a/linux-core/drm_bo.c b/linux-core/drm_bo.c index 171c074a..df10e12b 100644 --- a/linux-core/drm_bo.c +++ b/linux-core/drm_bo.c @@ -146,7 +146,7 @@ static int drm_bo_add_ttm(struct drm_buffer_object *bo) page_flags |= DRM_TTM_PAGE_WRITE; switch (bo->type) { - case drm_bo_type_dc: + case drm_bo_type_device: case drm_bo_type_kernel: bo->ttm = drm_ttm_create(dev, bo->num_pages << PAGE_SHIFT, page_flags, dev->bm.dummy_read_page); @@ -1155,7 +1155,12 @@ static void drm_bo_fill_rep_arg(struct drm_buffer_object *bo, rep->size = bo->num_pages * PAGE_SIZE; rep->offset = bo->offset; - if (bo->type == drm_bo_type_dc) + /* + * drm_bo_type_device buffers have user-visible + * handles which can be used to share across + * processes. Hand that back to the application + */ + if (bo->type == drm_bo_type_device) rep->arg_handle = bo->map_list.user_token; else rep->arg_handle = 0; @@ -1786,7 +1791,12 @@ int drm_buffer_object_create(struct drm_device *dev, if (ret) goto out_err; - if (bo->type == drm_bo_type_dc) { + /* + * For drm_bo_type_device buffers, allocate + * address space from the device so that applications + * can mmap the buffer from there + */ + if (bo->type == drm_bo_type_device) { mutex_lock(&dev->struct_mutex); ret = drm_bo_setup_vm_locked(bo); mutex_unlock(&dev->struct_mutex); @@ -1849,7 +1859,12 @@ int drm_bo_create_ioctl(struct drm_device *dev, void *data, struct drm_file *fil return -EINVAL; } - bo_type = (req->buffer_start) ? drm_bo_type_user : drm_bo_type_dc; + /* + * If the buffer creation request comes in with a starting address, + * that points at the desired user pages to map. Otherwise, create + * a drm_bo_type_device buffer, which uses pages allocated from the kernel + */ + bo_type = (req->buffer_start) ? drm_bo_type_user : drm_bo_type_device; /* * User buffers cannot be shared @@ -2607,6 +2622,14 @@ void drm_bo_unmap_virtual(struct drm_buffer_object *bo) unmap_mapping_range(dev->dev_mapping, offset, holelen, 1); } +/** + * drm_bo_takedown_vm_locked: + * + * @bo: the buffer object to remove any drm device mapping + * + * Remove any associated vm mapping on the drm device node that + * would have been created for a drm_bo_type_device buffer + */ static void drm_bo_takedown_vm_locked(struct drm_buffer_object *bo) { struct drm_map_list *list; @@ -2614,7 +2637,7 @@ static void drm_bo_takedown_vm_locked(struct drm_buffer_object *bo) struct drm_device *dev = bo->dev; DRM_ASSERT_LOCKED(&dev->struct_mutex); - if (bo->type != drm_bo_type_dc) + if (bo->type != drm_bo_type_device) return; list = &bo->map_list; @@ -2637,6 +2660,16 @@ static void drm_bo_takedown_vm_locked(struct drm_buffer_object *bo) drm_bo_usage_deref_locked(&bo); } +/** + * drm_bo_setup_vm_locked: + * + * @bo: the buffer to allocate address space for + * + * Allocate address space in the drm device so that applications + * can mmap the buffer and access the contents. This only + * applies to drm_bo_type_device objects as others are not + * placed in the drm device address space. + */ static int drm_bo_setup_vm_locked(struct drm_buffer_object *bo) { struct drm_map_list *list = &bo->map_list; diff --git a/linux-core/drm_objects.h b/linux-core/drm_objects.h index 98421e4c..a2d10b5d 100644 --- a/linux-core/drm_objects.h +++ b/linux-core/drm_objects.h @@ -404,9 +404,31 @@ struct drm_bo_mem_reg { }; enum drm_bo_type { - drm_bo_type_dc, + /* + * drm_bo_type_device are 'normal' drm allocations, + * pages are allocated from within the kernel automatically + * and the objects can be mmap'd from the drm device. Each + * drm_bo_type_device object has a unique name which can be + * used by other processes to share access to the underlying + * buffer. + */ + drm_bo_type_device, + /* + * drm_bo_type_user are buffers of pages that already exist + * in the process address space. They are more limited than + * drm_bo_type_device buffers in that they must always + * remain cached (as we assume the user pages are mapped cached), + * and they are not sharable to other processes through DRM + * (although, regular shared memory should still work fine). + */ drm_bo_type_user, - drm_bo_type_kernel, /* for initial kernel allocations */ + /* + * drm_bo_type_kernel are buffers that exist solely for use + * within the kernel. The pages cannot be mapped into the + * process. One obvious use would be for the ring + * buffer where user access would not (ideally) be required. + */ + drm_bo_type_kernel, }; struct drm_buffer_object { |