From da3601e43ae75695f3b080904b1e090c8eb1cd8e Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Sun, 16 Dec 2007 22:00:45 -0800 Subject: Change drm_bo_type_dc to drm_bo_type_device and comment usage of this value. I couldn't figure out what drm_bo_type_dc was for; Dave Airlie finally clued me in that it was the 'normal' buffer objects with kernel allocated pages that could be mmapped from the drm device file. I thought that 'drm_bo_type_device' was a more descriptive name. I also added a bunch of comments describing the use of the type enum values and the functions that use them. --- linux-core/drm_bo.c | 43 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 5 deletions(-) (limited to 'linux-core/drm_bo.c') 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; -- cgit v1.2.3