From 7dd737f377ffb59010b6811f934998d42f24a8bd Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 28 Oct 2016 13:58:38 +0100 Subject: [PATCH] drm/i915/dmabuf: Acquire the backing storage outside of struct_mutex Use the per-object mm.lock to allocate the backing storage (and hold a reference to it across the dmabuf access) without resorting to struct_mutex. Signed-off-by: Chris Wilson Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-15-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_dmabuf.c | 69 +++++++++++++++------------------- 1 file changed, 30 insertions(+), 39 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c index 2abd524..4d45f20 100644 --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c @@ -44,19 +44,15 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme struct scatterlist *src, *dst; int ret, i; - ret = i915_mutex_lock_interruptible(obj->base.dev); - if (ret) - goto err; - ret = i915_gem_object_pin_pages(obj); if (ret) - goto err_unlock; + goto err; /* Copy sg so that we make an independent mapping */ st = kmalloc(sizeof(struct sg_table), GFP_KERNEL); if (st == NULL) { ret = -ENOMEM; - goto err_unpin; + goto err_unpin_pages; } ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL); @@ -72,21 +68,18 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme } if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) { - ret =-ENOMEM; + ret = -ENOMEM; goto err_free_sg; } - mutex_unlock(&obj->base.dev->struct_mutex); return st; err_free_sg: sg_free_table(st); err_free: kfree(st); -err_unpin: +err_unpin_pages: i915_gem_object_unpin_pages(obj); -err_unlock: - mutex_unlock(&obj->base.dev->struct_mutex); err: return ERR_PTR(ret); } @@ -101,36 +94,21 @@ static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, sg_free_table(sg); kfree(sg); - mutex_lock(&obj->base.dev->struct_mutex); i915_gem_object_unpin_pages(obj); - mutex_unlock(&obj->base.dev->struct_mutex); } 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; - void *addr; - int ret; - - ret = i915_mutex_lock_interruptible(dev); - if (ret) - return ERR_PTR(ret); - - addr = i915_gem_object_pin_map(obj, I915_MAP_WB); - mutex_unlock(&dev->struct_mutex); - return addr; + return i915_gem_object_pin_map(obj, I915_MAP_WB); } static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) { struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); - struct drm_device *dev = obj->base.dev; - mutex_lock(&dev->struct_mutex); i915_gem_object_unpin_map(obj); - mutex_unlock(&dev->struct_mutex); } static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num) @@ -177,32 +155,45 @@ static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_dire { struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); struct drm_device *dev = obj->base.dev; - int ret; bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE); + int err; - ret = i915_mutex_lock_interruptible(dev); - if (ret) - return ret; + err = i915_gem_object_pin_pages(obj); + if (err) + return err; + + err = i915_mutex_lock_interruptible(dev); + if (err) + goto out; - ret = i915_gem_object_set_to_cpu_domain(obj, write); + err = i915_gem_object_set_to_cpu_domain(obj, write); mutex_unlock(&dev->struct_mutex); - return ret; + +out: + i915_gem_object_unpin_pages(obj); + return err; } static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction) { struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); struct drm_device *dev = obj->base.dev; - int ret; + int err; - ret = i915_mutex_lock_interruptible(dev); - if (ret) - return ret; + err = i915_gem_object_pin_pages(obj); + if (err) + return err; + + err = i915_mutex_lock_interruptible(dev); + if (err) + goto out; - ret = i915_gem_object_set_to_gtt_domain(obj, false); + err = i915_gem_object_set_to_gtt_domain(obj, false); mutex_unlock(&dev->struct_mutex); - return ret; +out: + i915_gem_object_unpin_pages(obj); + return err; } static const struct dma_buf_ops i915_dmabuf_ops = { -- 2.7.4