[Intel-gfx] [PATCH v2 3/6] drm/i915: Refactor duplicate object vmap functions
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Mon Apr 11 14:20:38 UTC 2016
On 08/04/16 12:11, Chris Wilson wrote:
> We now have two implementations for vmapping a whole object, one for
> dma-buf and one for the ringbuffer. If we couple the mapping into the
> obj->pages lifetime, then we can reuse an obj->mapping for both and at
> the same time couple it into the shrinker. There is a third vmapping
> routine in the cmdparser that maps only a range within the object, for
> the time being that is left alone, but will eventually use these routines
> in order to cache the mapping between invocations.
>
> v2: Mark the failable kmalloc() as __GFP_NOWARN (vsyrjala)
> v3: Call unpin_vmap from the right dmabuf unmapper
>
> v4: Rename vmap to map as we don't wish to imply the type of mapping
> involved, just that it contiguously maps the object into kernel space.
> Add kerneldoc and lockdep annotations
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Cc: Dave Gordon <david.s.gordon at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 37 ++++++++++++++++++++++---
> drivers/gpu/drm/i915/i915_gem.c | 44 +++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/i915_gem_dmabuf.c | 49 ++++-----------------------------
> drivers/gpu/drm/i915/intel_ringbuffer.c | 26 ++---------------
> 4 files changed, 84 insertions(+), 72 deletions(-)
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Regards,
Tvrtko
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index a93e5dd4fa9a..eda4218e2ede 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2169,10 +2169,7 @@ struct drm_i915_gem_object {
> struct scatterlist *sg;
> int last;
> } get_page;
> -
> - /* prime dma-buf support */
> - void *dma_buf_vmapping;
> - int vmapping_count;
> + void *mapping;
>
> /** Breadcrumb of last rendering to the buffer.
> * There can only be one writer, but we allow for multiple readers.
> @@ -2988,12 +2985,44 @@ static inline void i915_gem_object_pin_pages(struct drm_i915_gem_object *obj)
> BUG_ON(obj->pages == NULL);
> obj->pages_pin_count++;
> }
> +
> static inline void i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj)
> {
> BUG_ON(obj->pages_pin_count == 0);
> obj->pages_pin_count--;
> }
>
> +/**
> + * i915_gem_object_pin_map - return a contiguous mapping of the entire object
> + * @obj - the object to map into kernel address space
> + *
> + * Calls i915_gem_object_pin_pages() to prevent reaping of the object's
> + * pages and then returns a contiguous mapping of the backing storage into
> + * the kernel address space.
> + *
> + * The caller must hold the struct_mutex.
> + *
> + * Returns the pointer through which to access the backing storage.
> + */
> +void *__must_check i915_gem_object_pin_map(struct drm_i915_gem_object *obj);
> +
> +/**
> + * i915_gem_object_unpin_map - releases an earlier mapping
> + * @obj - the object to unmap
> + *
> + * After pinning the object and mapping its pages, once you are finished
> + * with your access, call i915_gem_object_unpin_map() to release the pin
> + * upon the mapping. Once the pin count reaches zero, that mapping may be
> + * removed.
> + *
> + * The caller must hold the struct_mutex.
> + */
> +static inline void i915_gem_object_unpin_map(struct drm_i915_gem_object *obj)
> +{
> + lockdep_assert_held(&obj->base.dev->struct_mutex);
> + i915_gem_object_unpin_pages(obj);
> +}
> +
> 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 5a65a7663b88..fcbd47d36dcf 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2232,6 +2232,11 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
> * lists early. */
> list_del(&obj->global_list);
>
> + if (obj->mapping) {
> + vunmap(obj->mapping);
> + obj->mapping = NULL;
> + }
> +
> ops->put_pages(obj);
> obj->pages = NULL;
>
> @@ -2400,6 +2405,45 @@ i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
> return 0;
> }
>
> +void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj)
> +{
> + int ret;
> +
> + lockdep_assert_held(&obj->base.dev->struct_mutex);
> +
> + ret = i915_gem_object_get_pages(obj);
> + if (ret)
> + return ERR_PTR(ret);
> +
> + i915_gem_object_pin_pages(obj);
> +
> + if (obj->mapping == NULL) {
> + struct sg_page_iter sg_iter;
> + struct page **pages;
> + int n;
> +
> + n = obj->base.size >> PAGE_SHIFT;
> + pages = kmalloc(n*sizeof(*pages), GFP_TEMPORARY | __GFP_NOWARN);
> + if (pages == NULL)
> + pages = drm_malloc_ab(n, sizeof(*pages));
> + if (pages != NULL) {
> + n = 0;
> + for_each_sg_page(obj->pages->sgl, &sg_iter,
> + obj->pages->nents, 0)
> + pages[n++] = sg_page_iter_page(&sg_iter);
> +
> + obj->mapping = vmap(pages, n, 0, PAGE_KERNEL);
> + drm_free_large(pages);
> + }
> + if (obj->mapping == NULL) {
> + i915_gem_object_unpin_pages(obj);
> + return ERR_PTR(-ENOMEM);
> + }
> + }
> +
> + return obj->mapping;
> +}
> +
> 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 b7d46800c49f..80bbe43a2e92 100644
> --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> @@ -108,51 +108,17 @@ 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;
> + void *addr;
> + int ret;
>
> ret = i915_mutex_lock_interruptible(dev);
> if (ret)
> return ERR_PTR(ret);
>
> - if (obj->dma_buf_vmapping) {
> - obj->vmapping_count++;
> - goto out_unlock;
> - }
> -
> - ret = i915_gem_object_get_pages(obj);
> - if (ret)
> - goto err;
> -
> - i915_gem_object_pin_pages(obj);
> -
> - 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);
> -
> - if (!obj->dma_buf_vmapping)
> - goto err_unpin;
> -
> - obj->vmapping_count = 1;
> -out_unlock:
> + addr = i915_gem_object_pin_map(obj);
> mutex_unlock(&dev->struct_mutex);
> - return obj->dma_buf_vmapping;
>
> -err_unpin:
> - i915_gem_object_unpin_pages(obj);
> -err:
> - mutex_unlock(&dev->struct_mutex);
> - return ERR_PTR(ret);
> + return addr;
> }
>
> static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> @@ -161,12 +127,7 @@ static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> struct drm_device *dev = obj->base.dev;
>
> mutex_lock(&dev->struct_mutex);
> - if (--obj->vmapping_count == 0) {
> - vunmap(obj->dma_buf_vmapping);
> - obj->dma_buf_vmapping = NULL;
> -
> - i915_gem_object_unpin_pages(obj);
> - }
> + i915_gem_object_unpin_map(obj);
> mutex_unlock(&dev->struct_mutex);
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 600ccc403b1f..83536c39b9ca 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -2078,35 +2078,13 @@ static int init_phys_status_page(struct intel_engine_cs *engine)
> void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf)
> {
> if (HAS_LLC(ringbuf->obj->base.dev) && !ringbuf->obj->stolen)
> - vunmap(ringbuf->virtual_start);
> + i915_gem_object_unpin_map(ringbuf->obj);
> else
> iounmap(ringbuf->virtual_start);
> - ringbuf->virtual_start = NULL;
> ringbuf->vma = NULL;
> 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)
> {
> @@ -2124,7 +2102,7 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
> if (ret)
> goto err_unpin;
>
> - ringbuf->virtual_start = vmap_obj(obj);
> + ringbuf->virtual_start = i915_gem_object_pin_map(obj);
> if (ringbuf->virtual_start == NULL) {
> ret = -ENOMEM;
> goto err_unpin;
>
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