static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
{
struct dma_buf *dmabuf;
+ int ret;
if (!is_dma_buf_file(file))
return -EINVAL;
dmabuf->size >> PAGE_SHIFT)
return -EINVAL;
- return dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_lock(dmabuf->resv, NULL);
+ ret = dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_unlock(dmabuf->resv);
+
+ return ret;
}
static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
init_waitqueue_head(&dmabuf->poll);
dmabuf->cb_in.poll = dmabuf->cb_out.poll = &dmabuf->poll;
dmabuf->cb_in.active = dmabuf->cb_out.active = 0;
- mutex_init(&dmabuf->lock);
INIT_LIST_HEAD(&dmabuf->attachments);
if (!resv) {
return sg_table;
}
+/**
+ * DOC: locking convention
+ *
+ * In order to avoid deadlock situations between dma-buf exports and importers,
+ * all dma-buf API users must follow the common dma-buf locking convention.
+ *
+ * Convention for importers
+ *
+ * 1. Importers must hold the dma-buf reservation lock when calling these
+ * functions:
+ *
+ * - dma_buf_pin()
+ * - dma_buf_unpin()
+ * - dma_buf_map_attachment()
+ * - dma_buf_unmap_attachment()
+ * - dma_buf_vmap()
+ * - dma_buf_vunmap()
+ *
+ * 2. Importers must not hold the dma-buf reservation lock when calling these
+ * functions:
+ *
+ * - dma_buf_attach()
+ * - dma_buf_dynamic_attach()
+ * - dma_buf_detach()
+ * - dma_buf_export(
+ * - dma_buf_fd()
+ * - dma_buf_get()
+ * - dma_buf_put()
+ * - dma_buf_mmap()
+ * - dma_buf_begin_cpu_access()
+ * - dma_buf_end_cpu_access()
+ * - dma_buf_map_attachment_unlocked()
+ * - dma_buf_unmap_attachment_unlocked()
+ * - dma_buf_vmap_unlocked()
+ * - dma_buf_vunmap_unlocked()
+ *
+ * Convention for exporters
+ *
+ * 1. These &dma_buf_ops callbacks are invoked with unlocked dma-buf
+ * reservation and exporter can take the lock:
+ *
+ * - &dma_buf_ops.attach()
+ * - &dma_buf_ops.detach()
+ * - &dma_buf_ops.release()
+ * - &dma_buf_ops.begin_cpu_access()
+ * - &dma_buf_ops.end_cpu_access()
+ *
+ * 2. These &dma_buf_ops callbacks are invoked with locked dma-buf
+ * reservation and exporter can't take the lock:
+ *
+ * - &dma_buf_ops.pin()
+ * - &dma_buf_ops.unpin()
+ * - &dma_buf_ops.map_dma_buf()
+ * - &dma_buf_ops.unmap_dma_buf()
+ * - &dma_buf_ops.mmap()
+ * - &dma_buf_ops.vmap()
+ * - &dma_buf_ops.vunmap()
+ *
+ * 3. Exporters must hold the dma-buf reservation lock when calling these
+ * functions:
+ *
+ * - dma_buf_move_notify()
+ */
+
/**
* dma_buf_dynamic_attach - Add the device to dma_buf's attachments list
* @dmabuf: [in] buffer to attach device to.
dma_buf_is_dynamic(dmabuf)) {
struct sg_table *sgt;
+ dma_resv_lock(attach->dmabuf->resv, NULL);
if (dma_buf_is_dynamic(attach->dmabuf)) {
- dma_resv_lock(attach->dmabuf->resv, NULL);
ret = dmabuf->ops->pin(attach);
if (ret)
goto err_unlock;
ret = PTR_ERR(sgt);
goto err_unpin;
}
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_unlock(attach->dmabuf->resv);
+ dma_resv_unlock(attach->dmabuf->resv);
attach->sgt = sgt;
attach->dir = DMA_BIDIRECTIONAL;
}
dmabuf->ops->unpin(attach);
err_unlock:
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_unlock(attach->dmabuf->resv);
+ dma_resv_unlock(attach->dmabuf->resv);
dma_buf_detach(dmabuf, attach);
return ERR_PTR(ret);
*/
void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
{
- if (WARN_ON(!dmabuf || !attach))
+ if (WARN_ON(!dmabuf || !attach || dmabuf != attach->dmabuf))
return;
+ dma_resv_lock(dmabuf->resv, NULL);
+
if (attach->sgt) {
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_lock(attach->dmabuf->resv, NULL);
__unmap_dma_buf(attach, attach->sgt, attach->dir);
- if (dma_buf_is_dynamic(attach->dmabuf)) {
+ if (dma_buf_is_dynamic(attach->dmabuf))
dmabuf->ops->unpin(attach);
- 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);
if (WARN_ON(!attach || !attach->dmabuf))
return ERR_PTR(-EINVAL);
- if (dma_buf_attachment_is_dynamic(attach))
- dma_resv_assert_held(attach->dmabuf->resv);
+ dma_resv_assert_held(attach->dmabuf->resv);
if (attach->sgt) {
/*
}
if (dma_buf_is_dynamic(attach->dmabuf)) {
- dma_resv_assert_held(attach->dmabuf->resv);
if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
r = attach->dmabuf->ops->pin(attach);
if (r)
}
EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment, DMA_BUF);
+/**
+ * dma_buf_map_attachment_unlocked - Returns the scatterlist table of the attachment;
+ * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
+ * dma_buf_ops.
+ * @attach: [in] attachment whose scatterlist is to be returned
+ * @direction: [in] direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_map_attachment().
+ */
+struct sg_table *
+dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,
+ enum dma_data_direction direction)
+{
+ struct sg_table *sg_table;
+
+ might_sleep();
+
+ if (WARN_ON(!attach || !attach->dmabuf))
+ return ERR_PTR(-EINVAL);
+
+ dma_resv_lock(attach->dmabuf->resv, NULL);
+ sg_table = dma_buf_map_attachment(attach, direction);
+ dma_resv_unlock(attach->dmabuf->resv);
+
+ return sg_table;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment_unlocked, DMA_BUF);
+
/**
* dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
* deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
return;
- if (dma_buf_attachment_is_dynamic(attach))
- dma_resv_assert_held(attach->dmabuf->resv);
+ 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);
-
__unmap_dma_buf(attach, sg_table, direction);
if (dma_buf_is_dynamic(attach->dmabuf) &&
}
EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment, DMA_BUF);
+/**
+ * dma_buf_unmap_attachment_unlocked - unmaps and decreases usecount of the buffer;might
+ * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
+ * dma_buf_ops.
+ * @attach: [in] attachment to unmap buffer from
+ * @sg_table: [in] scatterlist info of the buffer to unmap
+ * @direction: [in] direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_unmap_attachment().
+ */
+void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,
+ struct sg_table *sg_table,
+ enum dma_data_direction direction)
+{
+ might_sleep();
+
+ if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
+ return;
+
+ dma_resv_lock(attach->dmabuf->resv, NULL);
+ dma_buf_unmap_attachment(attach, sg_table, direction);
+ dma_resv_unlock(attach->dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment_unlocked, DMA_BUF);
+
/**
* dma_buf_move_notify - notify attachments that DMA-buf is moving
*
int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
unsigned long pgoff)
{
+ int ret;
+
if (WARN_ON(!dmabuf || !vma))
return -EINVAL;
vma_set_file(vma, dmabuf->file);
vma->vm_pgoff = pgoff;
- return dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_lock(dmabuf->resv, NULL);
+ ret = dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_unlock(dmabuf->resv);
+
+ return ret;
}
EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
{
struct iosys_map ptr;
- int ret = 0;
+ int ret;
iosys_map_clear(map);
if (WARN_ON(!dmabuf))
return -EINVAL;
+ dma_resv_assert_held(dmabuf->resv);
+
if (!dmabuf->ops->vmap)
return -EINVAL;
- mutex_lock(&dmabuf->lock);
if (dmabuf->vmapping_counter) {
dmabuf->vmapping_counter++;
BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
*map = dmabuf->vmap_ptr;
- goto out_unlock;
+ return 0;
}
BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));
ret = dmabuf->ops->vmap(dmabuf, &ptr);
if (WARN_ON_ONCE(ret))
- goto out_unlock;
+ return ret;
dmabuf->vmap_ptr = ptr;
dmabuf->vmapping_counter = 1;
*map = dmabuf->vmap_ptr;
-out_unlock:
- mutex_unlock(&dmabuf->lock);
- return ret;
+ return 0;
}
EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
+/**
+ * dma_buf_vmap_unlocked - Create virtual mapping for the buffer object into kernel
+ * address space. Same restrictions as for vmap and friends apply.
+ * @dmabuf: [in] buffer to vmap
+ * @map: [out] returns the vmap pointer
+ *
+ * Unlocked version of dma_buf_vmap()
+ *
+ * Returns 0 on success, or a negative errno code otherwise.
+ */
+int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+ int ret;
+
+ iosys_map_clear(map);
+
+ if (WARN_ON(!dmabuf))
+ return -EINVAL;
+
+ dma_resv_lock(dmabuf->resv, NULL);
+ ret = dma_buf_vmap(dmabuf, map);
+ dma_resv_unlock(dmabuf->resv);
+
+ return ret;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vmap_unlocked, DMA_BUF);
+
/**
* dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
* @dmabuf: [in] buffer to vunmap
if (WARN_ON(!dmabuf))
return;
+ dma_resv_assert_held(dmabuf->resv);
+
BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
BUG_ON(dmabuf->vmapping_counter == 0);
BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));
- mutex_lock(&dmabuf->lock);
if (--dmabuf->vmapping_counter == 0) {
if (dmabuf->ops->vunmap)
dmabuf->ops->vunmap(dmabuf, map);
iosys_map_clear(&dmabuf->vmap_ptr);
}
- mutex_unlock(&dmabuf->lock);
}
EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
+/**
+ * dma_buf_vunmap_unlocked - Unmap a vmap obtained by dma_buf_vmap.
+ * @dmabuf: [in] buffer to vunmap
+ * @map: [in] vmap pointer to vunmap
+ */
+void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+ if (WARN_ON(!dmabuf))
+ return;
+
+ dma_resv_lock(dmabuf->resv, NULL);
+ dma_buf_vunmap(dmabuf, map);
+ dma_resv_unlock(dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap_unlocked, DMA_BUF);
+
#ifdef CONFIG_DEBUG_FS
static int dma_buf_debug_show(struct seq_file *s, void *unused)
{
projects / linux-block.git / blobdiff