[PATCH 10/10] dma-buf/resv: add other operations

Christian König
2019-08-21T12:32:07Z

Additional to readers and writers add another class of operations
which never participate in implicit synchronization.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
drivers/dma-buf/dma-resv.c | 27 ++++++++++++++++++++++++---
include/linux/dma-resv.h | 2 ++
2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 8ef7dbc7fd8e..c6dd6c36dba2 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -280,6 +280,7 @@ void dma_resv_init(struct dma_resv *obj)

dma_resv_fences_init(&obj->writers);
dma_resv_fences_init(&obj->readers);
+ dma_resv_fences_init(&obj->others);
}
EXPORT_SYMBOL(dma_resv_init);

@@ -295,6 +296,7 @@ void dma_resv_fini(struct dma_resv *obj)
*/
dma_resv_fences_fini(&obj->writers);
dma_resv_fences_fini(&obj->readers);
+ dma_resv_fences_fini(&obj->others);
ww_mutex_destroy(&obj->lock);
}
EXPORT_SYMBOL(dma_resv_fini);
@@ -334,6 +336,10 @@ void dma_resv_prune_fences(struct dma_resv *obj)
fence = dma_resv_fences_deref(obj, &obj->readers);
if (dma_fence_is_signaled(fence))
dma_resv_fences_set(obj, &obj->readers, NULL);
+
+ fence = dma_resv_fences_deref(obj, &obj->others);
+ if (dma_fence_is_signaled(fence))
+ dma_resv_fences_set(obj, &obj->others, NULL);
}
EXPORT_SYMBOL(dma_resv_prune_fences);

@@ -346,17 +352,19 @@ EXPORT_SYMBOL(dma_resv_prune_fences);
*/
int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
{
- struct dma_fence *writers, *readers;
+ struct dma_fence *writers, *readers, *others;

dma_resv_assert_held(dst);

rcu_read_lock();
writers = dma_resv_fences_get_rcu(&src->writers);
readers = dma_resv_fences_get_rcu(&src->readers);
+ others = dma_resv_fences_get_rcu(&src->others);
rcu_read_unlock();

dma_resv_fences_set(dst, &dst->writers, writers);
dma_resv_fences_set(dst, &dst->readers, readers);
+ dma_resv_fences_set(dst, &dst->readers, others);

return 0;
}
@@ -440,12 +448,13 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj,
bool wait_all, bool intr,
unsigned long timeout)
{
- struct dma_fence *writers, *readers;
+ struct dma_fence *writers, *readers, *others;
long ret = timeout ? timeout : 1;

rcu_read_lock();
writers = dma_resv_fences_get_rcu(&obj->writers);
readers = dma_resv_fences_get_rcu(&obj->readers);
+ others = dma_resv_fences_get_rcu(&obj->others);
rcu_read_unlock();

if (wait_all && readers) {
@@ -454,12 +463,19 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj,
goto out;
}

+ if (wait_all && others) {
+ ret = dma_fence_wait_timeout(others, intr, ret);
+ if (ret <= 0)
+ goto out;
+ }
+
if (writers)
ret = dma_fence_wait_timeout(writers, intr, ret);

out:
dma_fence_put(writers);
dma_fence_put(readers);
+ dma_fence_put(others);
return ret;
}
EXPORT_SYMBOL_GPL(dma_resv_wait_timeout_rcu);
@@ -476,12 +492,13 @@ EXPORT_SYMBOL_GPL(dma_resv_wait_timeout_rcu);
*/
bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
{
- struct dma_fence *writers, *readers;
+ struct dma_fence *writers, *readers, *others;
bool ret = true;

rcu_read_lock();
writers = dma_resv_fences_get_rcu(&obj->writers);
readers = dma_resv_fences_get_rcu(&obj->readers);
+ others = dma_resv_fences_get_rcu(&obj->others);
rcu_read_unlock();

if (writers)
@@ -490,8 +507,12 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
if (test_all && readers)
ret &= dma_fence_is_signaled(readers);

+ if (test_all && others)
+ ret &= dma_fence_is_signaled(others);
+
dma_fence_put(writers);
dma_fence_put(readers);
+ dma_fence_put(others);

return ret;
}
diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
index 72c3c4f99711..bf8d21cc7720 100644
--- a/include/linux/dma-resv.h
+++ b/include/linux/dma-resv.h
@@ -76,12 +76,14 @@ void dma_resv_fences_commit(struct dma_resv *obj,
* @seq: sequence count for managing RCU read-side synchronization
* @writers: array of write operations for implicit sync
* @readers: array of read operations for implicit sync
+ * @others: other operations not participating in implicit sync
*/
struct dma_resv {
struct ww_mutex lock;

struct dma_resv_fences writers;
struct dma_resv_fences readers;
+ struct dma_resv_fences others;
};

#define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
--
2.17.1