From f45f57cce5841516bc53026b91952984d52e7126 Mon Sep 17 00:00:00 2001 From: Christian König Date: Fri, 18 Oct 2019 16:30:19 +0200 Subject: dma-buf: stop using the dmabuf->lock so much v2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The attachment list is now protected by the dma_resv object. Stop holding the dma_buf->lock while calling ->attach/->detach, this allows for concurrent attach/detach operations. v2: cleanup commit message and locking in _debug_show() Signed-off-by: Christian König Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/336790 --- drivers/dma-buf/dma-buf.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 0573879a222a..d377b4ca66bf 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -685,8 +685,6 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, attach->dmabuf = dmabuf; attach->dynamic_mapping = dynamic_mapping; - mutex_lock(&dmabuf->lock); - if (dmabuf->ops->attach) { ret = dmabuf->ops->attach(dmabuf, attach); if (ret) @@ -696,8 +694,6 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, list_add(&attach->node, &dmabuf->attachments); dma_resv_unlock(dmabuf->resv); - mutex_unlock(&dmabuf->lock); - /* When either the importer or the exporter can't handle dynamic * mappings we cache the mapping here to avoid issues with the * reservation object lock. @@ -726,7 +722,6 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, err_attach: kfree(attach); - mutex_unlock(&dmabuf->lock); return ERR_PTR(ret); err_unlock: @@ -776,14 +771,12 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) dma_resv_unlock(attach->dmabuf->resv); } - mutex_lock(&dmabuf->lock); dma_resv_lock(dmabuf->resv, NULL); list_del(&attach->node); dma_resv_unlock(dmabuf->resv); if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach); - mutex_unlock(&dmabuf->lock); kfree(attach); } EXPORT_SYMBOL_GPL(dma_buf_detach); @@ -1248,13 +1241,9 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) list_for_each_entry(buf_obj, &db_list.head, list_node) { - ret = mutex_lock_interruptible(&buf_obj->lock); - if (ret) - goto error_unlock_list; - ret = dma_resv_lock_interruptible(buf_obj->resv, NULL); if (ret) - goto error_unlock_buf; + goto error_unlock; seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n", buf_obj->size, @@ -1307,7 +1296,6 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) count++; size += buf_obj->size; - mutex_unlock(&buf_obj->lock); } seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size); @@ -1315,9 +1303,7 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) mutex_unlock(&db_list.lock); return 0; -error_unlock_buf: - mutex_unlock(&buf_obj->lock); -error_unlock_list: +error_unlock: mutex_unlock(&db_list.lock); return ret; } -- cgit v1.2.3