Fyi, Daniel Vetter had suggested on IRC that it would be cleaner to have a single helper fxn that most-restrictive union of all attached device's dma_parms. Really this should include dma_mask and coherent_dma_mask, I think. But that touches a lot of other places in the code. If no one objects to the cleanup of moving dma_mask/coherent_dma_mask into dma_parms, I'll do this first.
So anyways, don't consider this patch yet for inclusion, I'll make an updated one based on dma_parms..
BR, -R
On Thu, Jul 19, 2012 at 11:23 AM, Rob Clark rob.clark@linaro.org wrote:
From: Rob Clark rob@ti.com
Add some helpers to iterate through all attachers and get the most restrictive segment size/count/boundary.
Signed-off-by: Rob Clark rob@ti.com
drivers/base/dma-buf.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 19 ++++++++++++++ 2 files changed, 82 insertions(+)
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 24e88fe..757ee20 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -192,6 +192,69 @@ void dma_buf_put(struct dma_buf *dmabuf) EXPORT_SYMBOL_GPL(dma_buf_put);
/**
- dma_buf_max_seg_size - helper for exporters to get the minimum of
- all attached device's max segment size
- */
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf) +{
struct dma_buf_attachment *attach;unsigned int max = (unsigned int)-1;if (WARN_ON(!dmabuf))return 0;mutex_lock(&dmabuf->lock);list_for_each_entry(attach, &dmabuf->attachments, node)max = min(max, dma_get_max_seg_size(attach->dev));mutex_unlock(&dmabuf->lock);return max;+} +EXPORT_SYMBOL_GPL(dma_buf_max_seg_size);
+/**
- dma_buf_max_seg_count - helper for exporters to get the minimum of
- all attached device's max segment count
- */
+unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf) +{
struct dma_buf_attachment *attach;unsigned int max = (unsigned int)-1;if (WARN_ON(!dmabuf))return 0;mutex_lock(&dmabuf->lock);list_for_each_entry(attach, &dmabuf->attachments, node)max = min(max, dma_get_max_seg_count(attach->dev));mutex_unlock(&dmabuf->lock);return max;+} +EXPORT_SYMBOL_GPL(dma_buf_max_seg_count);
+/**
- dma_buf_get_seg_boundary - helper for exporters to get the most
- restrictive segment alignment of all the attached devices
- */
+unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf) +{
struct dma_buf_attachment *attach;unsigned int mask = (unsigned int)-1;if (WARN_ON(!dmabuf))return 0;mutex_lock(&dmabuf->lock);list_for_each_entry(attach, &dmabuf->attachments, node)mask &= dma_get_seg_boundary(attach->dev);mutex_unlock(&dmabuf->lock);return mask;+} +EXPORT_SYMBOL_GPL(dma_buf_get_seg_boundary);
+/**
- dma_buf_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.
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index eb48f38..9533b9b 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -167,6 +167,10 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags); struct dma_buf *dma_buf_get(int fd); void dma_buf_put(struct dma_buf *dmabuf);
+unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf); +unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf); +unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf);
struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, enum dma_data_direction); void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, @@ -220,6 +224,21 @@ static inline void dma_buf_put(struct dma_buf *dmabuf) return; }
+static inline unsigned int dma_buf_max_seg_size(struct dma_buf *dmabuf) +{
return 0;+}
+static inline unsigned int dma_buf_max_seg_count(struct dma_buf *dmabuf) +{
return 0;+}
+static inline unsigned int dma_buf_get_seg_boundary(struct dma_buf *dmabuf) +{
return 0;+}
static inline struct sg_table *dma_buf_map_attachment( struct dma_buf_attachment *attach, enum dma_data_direction write) { -- 1.7.9.5