@@ -15,6 +15,7 @@
#include <linux/wait.h>
struct completion;
+struct fence;
struct kfence {
wait_queue_head_t wait;
@@ -29,6 +30,9 @@ extern int kfence_add(struct kfence *fence, struct kfence *after, gfp_t gfp);
extern int kfence_add_completion(struct kfence *fence,
struct completion *x,
gfp_t gfp);
+extern int kfence_add_dma(struct kfence *fence,
+ struct fence *dma,
+ gfp_t gfp);
extern void kfence_pending(struct kfence *fence);
extern void kfence_signal(struct kfence *fence);
extern void kfence_wait(struct kfence *fence);
@@ -50,6 +50,7 @@ asynchronous and synchronous parts of the kernel.
#include <linux/async.h>
#include <linux/atomic.h>
+#include <linux/fence.h>
#include <linux/kfence.h>
#include <linux/ktime.h>
#include <linux/export.h>
@@ -122,9 +123,10 @@ static atomic_t entry_count;
* allowing multiple pending / signals to be sent before the kfence is
* complete.
*
- * kfence_add() / kfence_add_completion()
+ * kfence_add() / kfence_add_completion() / kfence_add_dma()
*
- * sets the kfence to wait upon another fence, or completion respectively.
+ * sets the kfence to wait upon another fence, completion, or DMA fence
+ * respectively.
*
* Unlike completions, kfences are expected to live inside more complex graphs
* and form the basis for parallel execution of interdependent and so are
@@ -484,6 +486,63 @@ int kfence_add_completion(struct kfence *fence, struct completion *x, gfp_t gfp)
}
EXPORT_SYMBOL_GPL(kfence_add_completion);
+struct dma_fence_cb {
+ struct fence_cb base;
+ struct kfence *fence;
+};
+
+static void dma_kfence_wake(struct fence *dma, struct fence_cb *data)
+{
+ struct dma_fence_cb *cb = container_of(data, typeof(*cb), base);
+ kfence_signal(cb->fence);
+ kfence_put(cb->fence);
+ kfree(cb);
+}
+
+/**
+ * kfence_add_dma - set the fence to wait upon a DMA fence
+ * @fence: this kfence
+ * @dma: target DMA fence to wait upon
+ * @gfp: the allowed allocation type
+ *
+ * kfence_add_dma() causes the @fence to wait upon completion of a DMA fence.
+ *
+ * Returns 1 if the @fence was successfully to the waitqueue of @dma, 0
+ * if @dma was already signaled (and so not added), or a negative error code.
+ */
+int kfence_add_dma(struct kfence *fence, struct fence *dma, gfp_t gfp)
+{
+ struct dma_fence_cb *cb;
+ int ret;
+
+ if (!dma || fence_is_signaled(dma))
+ return 0;
+
+ cb = kmalloc(sizeof(*cb), gfp);
+ if (!cb) {
+ if (!gfpflags_allow_blocking(gfp))
+ return -ENOMEM;
+
+ return fence_wait(dma, false);
+ }
+
+ cb->fence = kfence_get(fence);
+ kfence_pending(fence);
+
+ ret = fence_add_callback(dma, &cb->base, dma_kfence_wake);
+ if (ret == 0) {
+ /* signal fence add and is pending */
+ ret = 1;
+ } else {
+ dma_kfence_wake(dma, &cb->base);
+ if (ret == -ENOENT) /* fence already signaled */
+ ret = 0;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kfence_add_dma);
+
static async_cookie_t lowest_in_progress(struct async_domain *domain)
{
struct list_head *pending;
dma-buf provides an interfaces for receiving notifications from DMA hardware. kfence provides a useful interface for collecting such fences and combining them with other events. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Tejun Heo <tj@kernel.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: linux-kernel@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org --- include/linux/kfence.h | 4 ++++ kernel/async.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 65 insertions(+), 2 deletions(-)