This would give us a WARN_ON() if the pin/unpin calls are unbalanced.
Proposed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Reviewed-by: Tomi Valkeinen tomi.valkeinen@ti.com --- drivers/gpu/drm/omapdrm/omap_gem.c | 45 +++++++++++++++--------------- 1 file changed, 23 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c index 08f539efddfb..51ede7777083 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem.c +++ b/drivers/gpu/drm/omapdrm/omap_gem.c @@ -67,7 +67,7 @@ struct omap_gem_object { /** * # of users of dma_addr */ - u32 dma_addr_cnt; + refcount_t dma_addr_cnt;
/** * If the buffer has been imported from a dmabuf the OMAP_DB_DMABUF flag @@ -773,13 +773,15 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr) mutex_lock(&omap_obj->lock);
if (!omap_gem_is_contiguous(omap_obj) && priv->has_dmm) { - if (omap_obj->dma_addr_cnt == 0) { + if (refcount_read(&omap_obj->dma_addr_cnt) == 0) { u32 npages = obj->size >> PAGE_SHIFT; enum tiler_fmt fmt = gem2fmt(omap_obj->flags); struct tiler_block *block;
BUG_ON(omap_obj->block);
+ refcount_set(&omap_obj->dma_addr_cnt, 1); + ret = omap_gem_attach_pages(obj); if (ret) goto fail; @@ -813,10 +815,10 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr) omap_obj->block = block;
DBG("got dma address: %pad", &omap_obj->dma_addr); + } else { + refcount_inc(&omap_obj->dma_addr_cnt); }
- omap_obj->dma_addr_cnt++; - *dma_addr = omap_obj->dma_addr; } else if (omap_gem_is_contiguous(omap_obj)) { *dma_addr = omap_obj->dma_addr; @@ -846,23 +848,21 @@ void omap_gem_unpin(struct drm_gem_object *obj)
mutex_lock(&omap_obj->lock);
- if (omap_obj->dma_addr_cnt > 0) { - omap_obj->dma_addr_cnt--; - if (omap_obj->dma_addr_cnt == 0) { - ret = tiler_unpin(omap_obj->block); - if (ret) { - dev_err(obj->dev->dev, - "could not unpin pages: %d\n", ret); - } - ret = tiler_release(omap_obj->block); - if (ret) { - dev_err(obj->dev->dev, - "could not release unmap: %d\n", ret); - } - omap_obj->dma_addr = 0; - omap_obj->block = NULL; + if (refcount_dec_and_test(&omap_obj->dma_addr_cnt)) { + ret = tiler_unpin(omap_obj->block); + if (ret) { + dev_err(obj->dev->dev, + "could not unpin pages: %d\n", ret); } + ret = tiler_release(omap_obj->block); + if (ret) { + dev_err(obj->dev->dev, + "could not release unmap: %d\n", ret); + } + omap_obj->dma_addr = 0; + omap_obj->block = NULL; } +}
mutex_unlock(&omap_obj->lock); } @@ -879,7 +879,7 @@ int omap_gem_rotated_dma_addr(struct drm_gem_object *obj, u32 orient,
mutex_lock(&omap_obj->lock);
- if ((omap_obj->dma_addr_cnt > 0) && omap_obj->block && + if ((refcount_read(&omap_obj->dma_addr_cnt) > 0) && omap_obj->block && (omap_obj->flags & OMAP_BO_TILED)) { *dma_addr = tiler_tsptr(omap_obj->block, orient, x, y); ret = 0; @@ -1030,7 +1030,8 @@ void omap_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
seq_printf(m, "%08x: %2d (%2d) %08llx %pad (%2d) %p %4d", omap_obj->flags, obj->name, kref_read(&obj->refcount), - off, &omap_obj->dma_addr, omap_obj->dma_addr_cnt, + off, &omap_obj->dma_addr, + refcount_read(&omap_obj->dma_addr_cnt), omap_obj->vaddr, omap_obj->roll);
if (omap_obj->flags & OMAP_BO_TILED) { @@ -1093,7 +1094,7 @@ void omap_gem_free_object(struct drm_gem_object *obj) mutex_lock(&omap_obj->lock);
/* The object should not be pinned. */ - WARN_ON(omap_obj->dma_addr_cnt > 0); + WARN_ON(refcount_read(&omap_obj->dma_addr_cnt) > 0);
if (omap_obj->pages) { if (omap_obj->flags & OMAP_BO_MEM_DMABUF)