[Intel-gfx] [PATCH v5 3/7] drm/i915: introduce and use i915_gem_object_vmap_range()
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Mon Feb 29 11:53:27 UTC 2016
On 29/02/16 11:13, Dave Gordon wrote:
> From: Alex Dai <yu.dai at intel.com>
>
> There are several places inside driver where a GEM object is mapped
> to kernel virtual space. The mapping may be done either for the whole
> object or only a subset of it.
>
> This patch introduces a function i915_gem_object_vmap_range() to
> implement the common functionality. The code itself is extracted and
> adapted from that in vmap_batch(), but also replaces vmap_obj() and the
> open-coded version in i915_gem_dmabuf_vmap().
>
> v2: Use obj->pages->nents for iteration within i915_gem_object_vmap;
> break when it finishes all desired pages. The caller must pass the
> actual page count required. [Tvrtko Ursulin]
>
> v4: renamed to i915_gem_object_vmap_range() to make its function
> clearer. [Dave Gordon]
>
> v5: use Chris Wilson's new drm_malloc_gfp() rather than kmalloc() or
> drm_malloc_ab(). [Dave Gordon]
>
> Signed-off-by: Alex Dai <yu.dai at intel.com>
> Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_cmd_parser.c | 28 +-------------------
> drivers/gpu/drm/i915/i915_drv.h | 4 +++
> drivers/gpu/drm/i915/i915_gem.c | 47 +++++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/i915_gem_dmabuf.c | 16 +++--------
> drivers/gpu/drm/i915/intel_ringbuffer.c | 24 ++---------------
> 5 files changed, 57 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
> index 814d894..114b55f 100644
> --- a/drivers/gpu/drm/i915/i915_cmd_parser.c
> +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
> @@ -863,37 +863,11 @@ void i915_cmd_parser_fini_ring(struct intel_engine_cs *ring)
> static u32 *vmap_batch(struct drm_i915_gem_object *obj,
> unsigned start, unsigned len)
> {
> - int i;
> - void *addr = NULL;
> - struct sg_page_iter sg_iter;
> int first_page = start >> PAGE_SHIFT;
> int last_page = (len + start + 4095) >> PAGE_SHIFT;
> int npages = last_page - first_page;
> - struct page **pages;
> -
> - pages = drm_malloc_ab(npages, sizeof(*pages));
> - if (pages == NULL) {
> - DRM_DEBUG_DRIVER("Failed to get space for pages\n");
> - goto finish;
> - }
> -
> - i = 0;
> - for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, first_page) {
> - pages[i++] = sg_page_iter_page(&sg_iter);
> - if (i == npages)
> - break;
> - }
> -
> - addr = vmap(pages, i, 0, PAGE_KERNEL);
> - if (addr == NULL) {
> - DRM_DEBUG_DRIVER("Failed to vmap pages\n");
> - goto finish;
> - }
>
> -finish:
> - if (pages)
> - drm_free_large(pages);
> - return (u32*)addr;
> + return i915_gem_object_vmap_range(obj, first_page, npages);
> }
>
> /* Returns a vmap'd pointer to dest_obj, which the caller must unmap */
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 9e76bfc..918b0bb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2983,6 +2983,10 @@ static inline void i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj)
> obj->pages_pin_count--;
> }
>
> +void *__must_check i915_gem_object_vmap_range(struct drm_i915_gem_object *obj,
> + unsigned int first,
> + unsigned int npages);
> +
> int __must_check i915_mutex_lock_interruptible(struct drm_device *dev);
> int i915_gem_object_sync(struct drm_i915_gem_object *obj,
> struct intel_engine_cs *to,
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index f68f346..c621b3e 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2400,6 +2400,53 @@ static void i915_gem_object_free_mmap_offset(struct drm_i915_gem_object *obj)
> return 0;
> }
>
> +/**
> + * i915_gem_object_vmap_range - map some or all of a GEM object into kernel space
> + * @obj: the GEM object to be mapped
> + * @first: index of the first page of the object to be mapped
> + * @npages: length of the mapping to be created, in pages
> + *
> + * Map a given page range of a GEM object into kernel virtual space. The caller
> + * must make sure the associated pages are gathered and pinned before calling
> + * this function, and is responsible for vunmapping the returned address.
Could add an assert into the code for the above? (pages exist and are
pinned)
> + *
> + * Returns the address at which the object has been mapped, or NULL on failure.
> + */
> +void *i915_gem_object_vmap_range(struct drm_i915_gem_object *obj,
> + unsigned int first,
> + unsigned int npages)
> +{
> + struct sg_page_iter sg_iter;
> + struct page **pages;
> + void *addr;
> + int i;
> +
> + if (first + npages > obj->pages->nents) {
> + DRM_DEBUG_DRIVER("Invalid page count\n");
This is incorrect I think because nents is less or equal to number of
pages in an object. So it can fail the attempt incorrectly. Should
probably check against obj->base.size >> PAGE_SHIFT.
> + return NULL;
> + }
> +
> + pages = drm_malloc_gfp(npages, sizeof(*pages), GFP_TEMPORARY);
> + if (pages == NULL) {
> + DRM_DEBUG_DRIVER("Failed to get space for pages\n");
> + return NULL;
> + }
> +
> + i = 0;
> + for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, first) {
> + pages[i++] = sg_page_iter_page(&sg_iter);
> + if (i == npages)
> + break;
> + }
> +
> + addr = vmap(pages, npages, 0, PAGE_KERNEL);
> + if (addr == NULL)
> + DRM_DEBUG_DRIVER("Failed to vmap pages\n");
> + drm_free_large(pages);
> +
> + return addr;
> +}
> +
> void i915_vma_move_to_active(struct i915_vma *vma,
> struct drm_i915_gem_request *req)
> {
> diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> index 1f3eef6..aee4149 100644
> --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> @@ -110,9 +110,7 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> {
> struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
> struct drm_device *dev = obj->base.dev;
> - struct sg_page_iter sg_iter;
> - struct page **pages;
> - int ret, i;
> + int ret;
>
> ret = i915_mutex_lock_interruptible(dev);
> if (ret)
> @@ -131,16 +129,8 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
>
> ret = -ENOMEM;
>
> - pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
> - if (pages == NULL)
> - goto err_unpin;
> -
> - i = 0;
> - for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
> - pages[i++] = sg_page_iter_page(&sg_iter);
> -
> - obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
> - drm_free_large(pages);
> + obj->dma_buf_vmapping = i915_gem_object_vmap_range(obj, 0,
> + dma_buf->size >> PAGE_SHIFT);
>
> if (!obj->dma_buf_vmapping)
> goto err_unpin;
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 45ce45a..434a452 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -2064,27 +2064,6 @@ void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf)
> i915_gem_object_ggtt_unpin(ringbuf->obj);
> }
>
> -static u32 *vmap_obj(struct drm_i915_gem_object *obj)
> -{
> - struct sg_page_iter sg_iter;
> - struct page **pages;
> - void *addr;
> - int i;
> -
> - pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
> - if (pages == NULL)
> - return NULL;
> -
> - i = 0;
> - for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
> - pages[i++] = sg_page_iter_page(&sg_iter);
> -
> - addr = vmap(pages, i, 0, PAGE_KERNEL);
> - drm_free_large(pages);
> -
> - return addr;
> -}
> -
> int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
> struct intel_ringbuffer *ringbuf)
> {
> @@ -2103,7 +2082,8 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
> return ret;
> }
>
> - ringbuf->virtual_start = vmap_obj(obj);
> + ringbuf->virtual_start = i915_gem_object_vmap_range(obj, 0,
> + ringbuf->size >> PAGE_SHIFT);
> if (ringbuf->virtual_start == NULL) {
> i915_gem_object_ggtt_unpin(obj);
> return -ENOMEM;
>
Rest looks good to me.
Regards,
Tvrtko
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