From f2b974bdbbd3a5ad4869378915ca45f980992e4a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Fri, 24 Sep 2021 11:31:22 +0200
Subject: dma-buf: use the new iterator in dma_resv_poll
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Git-commit: 0a42016d9319db24d15789574fe132d8159d7578
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Simplify the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211005113742.1101-10-christian.koenig@amd.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/dma-buf/dma-buf.c | 36 ++++++------------------------------
 1 file changed, 6 insertions(+), 30 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 236560fd1e19..b03588459862 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -209,19 +209,14 @@ static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
 	dma_fence_put(fence);
 }
 
-static bool dma_buf_poll_shared(struct dma_resv *resv,
+static bool dma_buf_poll_add_cb(struct dma_resv *resv, bool write,
 				struct dma_buf_poll_cb_t *dcb)
 {
-	struct dma_resv_list *fobj = dma_resv_shared_list(resv);
+	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
-	int i, r;
-
-	if (!fobj)
-		return false;
+	int r;
 
-	for (i = 0; i < fobj->shared_count; ++i) {
-		fence = rcu_dereference_protected(fobj->shared[i],
-						  dma_resv_held(resv));
+	dma_resv_for_each_fence(&cursor, resv, write, fence) {
 		dma_fence_get(fence);
 		r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
 		if (!r)
@@ -232,24 +227,6 @@ static bool dma_buf_poll_shared(struct dma_resv *resv,
 	return false;
 }
 
-static bool dma_buf_poll_excl(struct dma_resv *resv,
-			      struct dma_buf_poll_cb_t *dcb)
-{
-	struct dma_fence *fence = dma_resv_excl_fence(resv);
-	int r;
-
-	if (!fence)
-		return false;
-
-	dma_fence_get(fence);
-	r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
-	if (!r)
-		return true;
-	dma_fence_put(fence);
-
-	return false;
-}
-
 static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
 {
 	struct dma_buf *dmabuf;
@@ -282,8 +259,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
 		spin_unlock_irq(&dmabuf->poll.lock);
 
 		if (events & EPOLLOUT) {
-			if (!dma_buf_poll_shared(resv, dcb) &&
-			    !dma_buf_poll_excl(resv, dcb))
+			if (!dma_buf_poll_add_cb(resv, true, dcb))
 				/* No callback queued, wake up any other waiters */
 				dma_buf_poll_cb(NULL, &dcb->cb);
 			else
@@ -303,7 +279,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
 		spin_unlock_irq(&dmabuf->poll.lock);
 
 		if (events & EPOLLIN) {
-			if (!dma_buf_poll_excl(resv, dcb))
+			if (!dma_buf_poll_add_cb(resv, false, dcb))
 				/* No callback queued, wake up any other waiters */
 				dma_buf_poll_cb(NULL, &dcb->cb);
 			else
-- 
2.38.1