From 5cfacdedb1a94efd29faeaab53f939554a3f5943 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 26 Aug 2013 19:50:55 -0300 Subject: [PATCH] drm/i915: Pin pages whilst mapping the dma-buf As we attempt to kmalloc after calling get_pages, there is a possibility that the shrinker may reap the pages we just acquired. To prevent this we need to increment the pages_pin_count early, so rearrange the code and error paths to make it so. Signed-off-by: Chris Wilson Reviewed-by: Damien Lespiau Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_dmabuf.c | 41 ++++++++++++++------------ 1 file changed, 22 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c index e918b05fcbdd..7d5752fda5f1 100644 --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c @@ -42,27 +42,24 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme ret = i915_mutex_lock_interruptible(obj->base.dev); if (ret) - return ERR_PTR(ret); + goto err; ret = i915_gem_object_get_pages(obj); - if (ret) { - st = ERR_PTR(ret); - goto out; - } + if (ret) + goto err_unlock; + + i915_gem_object_pin_pages(obj); /* Copy sg so that we make an independent mapping */ st = kmalloc(sizeof(struct sg_table), GFP_KERNEL); if (st == NULL) { - st = ERR_PTR(-ENOMEM); - goto out; + ret = -ENOMEM; + goto err_unpin; } ret = sg_alloc_table(st, obj->pages->nents, GFP_KERNEL); - if (ret) { - kfree(st); - st = ERR_PTR(ret); - goto out; - } + if (ret) + goto err_free; src = obj->pages->sgl; dst = st->sgl; @@ -73,17 +70,23 @@ 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)) { - sg_free_table(st); - kfree(st); - st = ERR_PTR(-ENOMEM); - goto out; + ret =-ENOMEM; + goto err_free_sg; } - i915_gem_object_pin_pages(obj); - -out: mutex_unlock(&obj->base.dev->struct_mutex); return st; + +err_free_sg: + sg_free_table(st); +err_free: + kfree(st); +err_unpin: + i915_gem_object_unpin_pages(obj); +err_unlock: + mutex_unlock(&obj->base.dev->struct_mutex); +err: + return ERR_PTR(ret); } static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, -- 2.20.1