summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorThomas Zimmermann <tzimmermann@suse.de>2020-09-25 13:55:58 +0200
committerThomas Zimmermann <tzimmermann@suse.de>2020-09-29 12:40:36 +0200
commit01fd30da0474d5528d96a154cb50ce3b0352fd19 (patch)
treee8b85a9fa2d4d338da76b6527f7adb5138ec16a3 /drivers
parent79b4d4d26bd256a0c7e3ce74c13a64797d98d1ac (diff)
dma-buf: Add struct dma-buf-map for storing struct dma_buf.vaddr_ptr
The new type struct dma_buf_map represents a mapping of dma-buf memory into kernel space. It contains a flag, is_iomem, that signals users to access the mapped memory with I/O operations instead of regular loads and stores. It was assumed that DMA buffer memory can be accessed with regular load and store operations. Some architectures, such as sparc64, require the use of I/O operations to access dma-map buffers that are located in I/O memory. Providing struct dma_buf_map allows drivers to implement this. This was specifically a problem when refreshing the graphics framebuffer on such systems. [1] As the first step, struct dma_buf stores an instance of struct dma_buf_map internally. Afterwards, dma-buf's vmap and vunmap interfaces are be converted. Finally, affected drivers can be fixed. v3: * moved documentation into separate patch * test for NULL pointers with !<ptr> [1] https://lore.kernel.org/dri-devel/20200725191012.GA434957@ravnborg.org/ Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-2-tzimmermann@suse.de
Diffstat (limited to 'drivers')
-rw-r--r--drivers/dma-buf/dma-buf.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 58564d82a3a2..5e849ca241a0 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1207,12 +1207,12 @@ void *dma_buf_vmap(struct dma_buf *dmabuf)
mutex_lock(&dmabuf->lock);
if (dmabuf->vmapping_counter) {
dmabuf->vmapping_counter++;
- BUG_ON(!dmabuf->vmap_ptr);
- ptr = dmabuf->vmap_ptr;
+ BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr));
+ ptr = dmabuf->vmap_ptr.vaddr;
goto out_unlock;
}
- BUG_ON(dmabuf->vmap_ptr);
+ BUG_ON(dma_buf_map_is_set(&dmabuf->vmap_ptr));
ptr = dmabuf->ops->vmap(dmabuf);
if (WARN_ON_ONCE(IS_ERR(ptr)))
@@ -1220,7 +1220,7 @@ void *dma_buf_vmap(struct dma_buf *dmabuf)
if (!ptr)
goto out_unlock;
- dmabuf->vmap_ptr = ptr;
+ dmabuf->vmap_ptr.vaddr = ptr;
dmabuf->vmapping_counter = 1;
out_unlock:
@@ -1239,15 +1239,15 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
if (WARN_ON(!dmabuf))
return;
- BUG_ON(!dmabuf->vmap_ptr);
+ BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr));
BUG_ON(dmabuf->vmapping_counter == 0);
- BUG_ON(dmabuf->vmap_ptr != vaddr);
+ BUG_ON(!dma_buf_map_is_vaddr(&dmabuf->vmap_ptr, vaddr));
mutex_lock(&dmabuf->lock);
if (--dmabuf->vmapping_counter == 0) {
if (dmabuf->ops->vunmap)
dmabuf->ops->vunmap(dmabuf, vaddr);
- dmabuf->vmap_ptr = NULL;
+ dma_buf_map_clear(&dmabuf->vmap_ptr);
}
mutex_unlock(&dmabuf->lock);
}