1 files changed, 95 insertions, 25 deletions

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 5b8797be80df..ce41cd9b758a 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -45,10 +45,10 @@ static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
 	size_t ret = 0;
 
 	dmabuf = dentry->d_fsdata;
-	mutex_lock(&dmabuf->lock);
+	dma_resv_lock(dmabuf->resv, NULL);
 	if (dmabuf->name)
 		ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN);
-	mutex_unlock(&dmabuf->lock);
+	dma_resv_unlock(dmabuf->resv);
 
 	return dynamic_dname(dentry, buffer, buflen, "/%s:%s",
 			     dentry->d_name.name, ret > 0 ? name : "");
@@ -334,7 +334,7 @@ static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf)
 	if (IS_ERR(name))
 		return PTR_ERR(name);
 
-	mutex_lock(&dmabuf->lock);
+	dma_resv_lock(dmabuf->resv, NULL);
 	if (!list_empty(&dmabuf->attachments)) {
 		ret = -EBUSY;
 		kfree(name);
@@ -344,7 +344,7 @@ static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf)
 	dmabuf->name = name;
 
 out_unlock:
-	mutex_unlock(&dmabuf->lock);
+	dma_resv_unlock(dmabuf->resv);
 	return ret;
 }
 
@@ -403,10 +403,10 @@ static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file)
 	/* Don't count the temporary reference taken inside procfs seq_show */
 	seq_printf(m, "count:\t%ld\n", file_count(dmabuf->file) - 1);
 	seq_printf(m, "exp_name:\t%s\n", dmabuf->exp_name);
-	mutex_lock(&dmabuf->lock);
+	dma_resv_lock(dmabuf->resv, NULL);
 	if (dmabuf->name)
 		seq_printf(m, "name:\t%s\n", dmabuf->name);
-	mutex_unlock(&dmabuf->lock);
+	dma_resv_unlock(dmabuf->resv);
 }
 
 static const struct file_operations dma_buf_fops = {
@@ -523,6 +523,10 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 		return ERR_PTR(-EINVAL);
 	}
 
+	if (WARN_ON(exp_info->ops->cache_sgt_mapping &&
+		    exp_info->ops->dynamic_mapping))
+		return ERR_PTR(-EINVAL);
+
 	if (!try_module_get(exp_info->owner))
 		return ERR_PTR(-ENOENT);
 
@@ -643,10 +647,11 @@ void dma_buf_put(struct dma_buf *dmabuf)
 EXPORT_SYMBOL_GPL(dma_buf_put);
 
 /**
- * dma_buf_attach - Add the device to dma_buf's attachments list; optionally,
+ * dma_buf_dynamic_attach - Add the device to dma_buf's attachments list; optionally,
  * calls attach() of dma_buf_ops to allow device-specific attach functionality
- * @dmabuf:	[in]	buffer to attach device to.
- * @dev:	[in]	device to be attached.
+ * @dmabuf:		[in]	buffer to attach device to.
+ * @dev:		[in]	device to be attached.
+ * @dynamic_mapping:	[in]	calling convention for map/unmap
  *
  * Returns struct dma_buf_attachment pointer for this attachment. Attachments
  * must be cleaned up by calling dma_buf_detach().
@@ -660,8 +665,9 @@ EXPORT_SYMBOL_GPL(dma_buf_put);
  * accessible to @dev, and cannot be moved to a more suitable place. This is
  * indicated with the error code -EBUSY.
  */
-struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
-					  struct device *dev)
+struct dma_buf_attachment *
+dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
+		       bool dynamic_mapping)
 {
 	struct dma_buf_attachment *attach;
 	int ret;
@@ -675,25 +681,69 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
 
 	attach->dev = dev;
 	attach->dmabuf = dmabuf;
-
-	mutex_lock(&dmabuf->lock);
+	attach->dynamic_mapping = dynamic_mapping;
 
 	if (dmabuf->ops->attach) {
 		ret = dmabuf->ops->attach(dmabuf, attach);
 		if (ret)
 			goto err_attach;
 	}
+	dma_resv_lock(dmabuf->resv, NULL);
 	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.
+	 */
+	if (dma_buf_attachment_is_dynamic(attach) !=
+	    dma_buf_is_dynamic(dmabuf)) {
+		struct sg_table *sgt;
+
+		if (dma_buf_is_dynamic(attach->dmabuf))
+			dma_resv_lock(attach->dmabuf->resv, NULL);
+
+		sgt = dmabuf->ops->map_dma_buf(attach, DMA_BIDIRECTIONAL);
+		if (!sgt)
+			sgt = ERR_PTR(-ENOMEM);
+		if (IS_ERR(sgt)) {
+			ret = PTR_ERR(sgt);
+			goto err_unlock;
+		}
+		if (dma_buf_is_dynamic(attach->dmabuf))
+			dma_resv_unlock(attach->dmabuf->resv);
+		attach->sgt = sgt;
+		attach->dir = DMA_BIDIRECTIONAL;
+	}
 
 	return attach;
 
 err_attach:
 	kfree(attach);
-	mutex_unlock(&dmabuf->lock);
+	return ERR_PTR(ret);
+
+err_unlock:
+	if (dma_buf_is_dynamic(attach->dmabuf))
+		dma_resv_unlock(attach->dmabuf->resv);
+
+	dma_buf_detach(dmabuf, attach);
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(dma_buf_dynamic_attach);
+
+/**
+ * dma_buf_attach - Wrapper for dma_buf_dynamic_attach
+ * @dmabuf:	[in]	buffer to attach device to.
+ * @dev:	[in]	device to be attached.
+ *
+ * Wrapper to call dma_buf_dynamic_attach() for drivers which still use a static
+ * mapping.
+ */
+struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
+					  struct device *dev)
+{
+	return dma_buf_dynamic_attach(dmabuf, dev, false);
+}
 EXPORT_SYMBOL_GPL(dma_buf_attach);
 
 /**
@@ -709,15 +759,22 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
 	if (WARN_ON(!dmabuf || !attach))
 		return;
 
-	if (attach->sgt)
+	if (attach->sgt) {
+		if (dma_buf_is_dynamic(attach->dmabuf))
+			dma_resv_lock(attach->dmabuf->resv, NULL);
+
 		dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir);
 
-	mutex_lock(&dmabuf->lock);
+		if (dma_buf_is_dynamic(attach->dmabuf))
+			dma_resv_unlock(attach->dmabuf->resv);
+	}
+
+	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);
@@ -747,6 +804,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf))
 		return ERR_PTR(-EINVAL);
 
+	if (dma_buf_attachment_is_dynamic(attach))
+		dma_resv_assert_held(attach->dmabuf->resv);
+
 	if (attach->sgt) {
 		/*
 		 * Two mappings with different directions for the same
@@ -759,6 +819,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 		return attach->sgt;
 	}
 
+	if (dma_buf_is_dynamic(attach->dmabuf))
+		dma_resv_assert_held(attach->dmabuf->resv);
+
 	sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
 	if (!sg_table)
 		sg_table = ERR_PTR(-ENOMEM);
@@ -791,9 +854,15 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
 		return;
 
+	if (dma_buf_attachment_is_dynamic(attach))
+		dma_resv_assert_held(attach->dmabuf->resv);
+
 	if (attach->sgt == sg_table)
 		return;
 
+	if (dma_buf_is_dynamic(attach->dmabuf))
+		dma_resv_assert_held(attach->dmabuf->resv);
+
 	attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction);
 }
 EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
@@ -1169,13 +1238,10 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
 		   "size", "flags", "mode", "count", "ino");
 
 	list_for_each_entry(buf_obj, &db_list.head, list_node) {
-		ret = mutex_lock_interruptible(&buf_obj->lock);
 
-		if (ret) {
-			seq_puts(s,
-				 "\tERROR locking buffer object: skipping\n");
-			continue;
-		}
+		ret = dma_resv_lock_interruptible(buf_obj->resv, NULL);
+		if (ret)
+			goto error_unlock;
 
 		seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n",
 				buf_obj->size,
@@ -1221,19 +1287,23 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
 			seq_printf(s, "\t%s\n", dev_name(attach_obj->dev));
 			attach_count++;
 		}
+		dma_resv_unlock(buf_obj->resv);
 
 		seq_printf(s, "Total %d devices attached\n\n",
 				attach_count);
 
 		count++;
 		size += buf_obj->size;
-		mutex_unlock(&buf_obj->lock);
 	}
 
 	seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
 
 	mutex_unlock(&db_list.lock);
 	return 0;
+
+error_unlock:
+	mutex_unlock(&db_list.lock);
+	return ret;
 }
 
 DEFINE_SHOW_ATTRIBUTE(dma_buf_debug);