Merge tag 'tilcdc-4.19' of https://github.com/jsarha/linux into drm-next

[sfrench/cifs-2.6.git] / drivers / dma-buf / dma-buf.c

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index d78d5fc173dc3d9b05b523462301a060e5482473..13884474d1588f7a086154d3b06dbd09ff28e881 100644 (file)
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -405,7 +405,6 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
                          || !exp_info->ops->map_dma_buf
                          || !exp_info->ops->unmap_dma_buf
                          || !exp_info->ops->release
-                         || !exp_info->ops->map_atomic
                          || !exp_info->ops->map
                          || !exp_info->ops->mmap)) {
                return ERR_PTR(-EINVAL);
@@ -568,7 +567,7 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
        mutex_lock(&dmabuf->lock);
 
        if (dmabuf->ops->attach) {
-               ret = dmabuf->ops->attach(dmabuf, dev, attach);
+               ret = dmabuf->ops->attach(dmabuf, attach);
                if (ret)
                        goto err_attach;
        }
@@ -687,26 +686,14 @@ EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
  *      void \*dma_buf_kmap(struct dma_buf \*, unsigned long);
  *      void dma_buf_kunmap(struct dma_buf \*, unsigned long, void \*);
  *
- *   There are also atomic variants of these interfaces. Like for kmap they
- *   facilitate non-blocking fast-paths. Neither the importer nor the exporter
- *   (in the callback) is allowed to block when using these.
- *
- *   Interfaces::
- *      void \*dma_buf_kmap_atomic(struct dma_buf \*, unsigned long);
- *      void dma_buf_kunmap_atomic(struct dma_buf \*, unsigned long, void \*);
- *
- *   For importers all the restrictions of using kmap apply, like the limited
- *   supply of kmap_atomic slots. Hence an importer shall only hold onto at
- *   max 2 atomic dma_buf kmaps at the same time (in any given process context).
+ *   Implementing the functions is optional for exporters and for importers all
+ *   the restrictions of using kmap apply.
  *
  *   dma_buf kmap calls outside of the range specified in begin_cpu_access are
  *   undefined. If the range is not PAGE_SIZE aligned, kmap needs to succeed on
  *   the partial chunks at the beginning and end but may return stale or bogus
  *   data outside of the range (in these partial chunks).
  *
- *   Note that these calls need to always succeed. The exporter needs to
- *   complete any preparations that might fail in begin_cpu_access.
- *
  *   For some cases the overhead of kmap can be too high, a vmap interface
  *   is introduced. This interface should be used very carefully, as vmalloc
  *   space is a limited resources on many architectures.
@@ -859,41 +846,6 @@ int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
 }
 EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
 
-/**
- * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address
- * space. The same restrictions as for kmap_atomic and friends apply.
- * @dmabuf:    [in]    buffer to map page from.
- * @page_num:  [in]    page in PAGE_SIZE units to map.
- *
- * This call must always succeed, any necessary preparations that might fail
- * need to be done in begin_cpu_access.
- */
-void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num)
-{
-       WARN_ON(!dmabuf);
-
-       return dmabuf->ops->map_atomic(dmabuf, page_num);
-}
-EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic);
-
-/**
- * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic.
- * @dmabuf:    [in]    buffer to unmap page from.
- * @page_num:  [in]    page in PAGE_SIZE units to unmap.
- * @vaddr:     [in]    kernel space pointer obtained from dma_buf_kmap_atomic.
- *
- * This call must always succeed.
- */
-void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num,
-                          void *vaddr)
-{
-       WARN_ON(!dmabuf);
-
-       if (dmabuf->ops->unmap_atomic)
-               dmabuf->ops->unmap_atomic(dmabuf, page_num, vaddr);
-}
-EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic);
-
 /**
  * dma_buf_kmap - Map a page of the buffer object into kernel address space. The
  * same restrictions as for kmap and friends apply.
@@ -907,6 +859,8 @@ void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
 {
        WARN_ON(!dmabuf);
 
+       if (!dmabuf->ops->map)
+               return NULL;
        return dmabuf->ops->map(dmabuf, page_num);
 }
 EXPORT_SYMBOL_GPL(dma_buf_kmap);