reservation: update api and add some helpers

Move the list of shared fences to a struct, and return it in
reservation_object_get_list().
Add reservation_object_get_excl to get the exclusive fence.

Add reservation_object_reserve_shared(), which reserves space
in the reservation_object for 1 more shared fence.

reservation_object_add_shared_fence() and
reservation_object_add_excl_fence() are used to assign a new
fence to a reservation_object pointer, to complete a reservation.

Changes since v1:
- Add reservation_object_get_excl, reorder code a bit.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 25e8c4165936..cb8379dfeed5 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -134,7 +134,10 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll)
 {
         struct dma_buf *dmabuf;
         struct reservation_object *resv;
+        struct reservation_object_list *fobj;
+        struct fence *fence_excl;
         unsigned long events;
+        unsigned shared_count;
 
         dmabuf = file->private_data;
         if (!dmabuf || !dmabuf->resv)
@@ -150,12 +153,18 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll)
 
         ww_mutex_lock(&resv->lock, NULL);
 
-        if (resv->fence_excl && (!(events & POLLOUT) ||
-                                 resv->fence_shared_count == 0)) {
+        fobj = resv->fence;
+        if (!fobj)
+                goto out;
+
+        shared_count = fobj->shared_count;
+        fence_excl = resv->fence_excl;
+
+        if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) {
                 struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl;
                 unsigned long pevents = POLLIN;
 
-                if (resv->fence_shared_count == 0)
+                if (shared_count == 0)
                         pevents |= POLLOUT;
 
                 spin_lock_irq(&dmabuf->poll.lock);
@@ -167,19 +176,20 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll)
                 spin_unlock_irq(&dmabuf->poll.lock);
 
                 if (events & pevents) {
-                        if (!fence_add_callback(resv->fence_excl,
-                                                &dcb->cb, dma_buf_poll_cb))
+                        if (!fence_add_callback(fence_excl, &dcb->cb,
+                                                       dma_buf_poll_cb)) {
                                 events &= ~pevents;
-                        else
+                        } else {
                                 /*
                                  * No callback queued, wake up any additional
                                  * waiters.
                                  */
                                 dma_buf_poll_cb(NULL, &dcb->cb);
+                        }
                 }
         }
 
-        if ((events & POLLOUT) && resv->fence_shared_count > 0) {
+        if ((events & POLLOUT) && shared_count > 0) {
                 struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared;
                 int i;
 
@@ -194,15 +204,18 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll)
                 if (!(events & POLLOUT))
                         goto out;
 
-                for (i = 0; i < resv->fence_shared_count; ++i)
-                        if (!fence_add_callback(resv->fence_shared[i],
-                                                &dcb->cb, dma_buf_poll_cb)) {
+                for (i = 0; i < shared_count; ++i) {
+                        struct fence *fence = fobj->shared[i];
+
+                        if (!fence_add_callback(fence, &dcb->cb,
+                                                dma_buf_poll_cb)) {
                                 events &= ~POLLOUT;
                                 break;
                         }
+                }
 
                 /* No callback queued, wake up any additional waiters. */
-                if (i == resv->fence_shared_count)
+                if (i == shared_count)
                         dma_buf_poll_cb(NULL, &dcb->cb);
         }