--- /dev/null
+/*
+ * Copyright © 2008 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ * Eric Anholt <eric@anholt.net>
+ *
+ */
+
+/**
+ * \file
+ * \brief Support for GL_ARB_sync and EGL_KHR_fence_sync.
+ *
+ * GL_ARB_sync is implemented by flushing the current batchbuffer and keeping a
+ * reference on it. We can then check for completion or wait for completion
+ * using the normal buffer object mechanisms. This does mean that if an
+ * application is using many sync objects, it will emit small batchbuffers
+ * which may end up being a significant overhead. In other tests of removing
+ * gratuitous batchbuffer syncs in Mesa, it hasn't appeared to be a significant
+ * performance bottleneck, though.
+ */
+
+#include "main/imports.h"
+
+#include "intel_context.h"
+#include "intel_batchbuffer.h"
+#include "intel_reg.h"
+
+struct intel_fence {
+ struct intel_context *intel;
+ /** The fence waits for completion of this batch. */
+ drm_intel_bo *batch_bo;
+
+ mtx_t mutex;
+ bool signalled;
+};
+
+struct intel_gl_sync_object {
+ struct gl_sync_object Base;
+ struct intel_fence fence;
+};
+
+static void
+intel_fence_finish(struct intel_fence *fence)
+{
+ if (fence->batch_bo)
+ drm_intel_bo_unreference(fence->batch_bo);
+}
+
+static void
+intel_fence_insert(struct intel_context *intel, struct intel_fence *fence)
+{
+ assert(!fence->batch_bo);
+ assert(!fence->signalled);
+
+ intel_batchbuffer_emit_mi_flush(intel);
+ fence->batch_bo = intel->batch.bo;
+ drm_intel_bo_reference(fence->batch_bo);
+ intel_batchbuffer_flush(intel);
+}
+
+static bool
+intel_fence_has_completed_locked(struct intel_fence *fence)
+{
+ if (fence->signalled)
+ return true;
+
+ if (fence->batch_bo && !drm_intel_bo_busy(fence->batch_bo)) {
+ drm_intel_bo_unreference(fence->batch_bo);
+ fence->batch_bo = NULL;
+ fence->signalled = true;
+ return true;
+ }
+
+ return false;
+}
+
+static bool
+intel_fence_has_completed(struct intel_fence *fence)
+{
+ bool ret;
+
+ mtx_lock(&fence->mutex);
+ ret = intel_fence_has_completed_locked(fence);
+ mtx_unlock(&fence->mutex);
+
+ return ret;
+}
+
+static bool
+intel_fence_client_wait_locked(struct intel_context *intel, struct intel_fence *fence,
+ uint64_t timeout)
+{
+ if (fence->signalled)
+ return true;
+
+ assert(fence->batch_bo);
+
+ /* DRM_IOCTL_I915_GEM_WAIT uses a signed 64 bit timeout and returns
+ * immediately for timeouts <= 0. The best we can do is to clamp the
+ * timeout to INT64_MAX. This limits the maximum timeout from 584 years to
+ * 292 years - likely not a big deal.
+ */
+ if (timeout > INT64_MAX)
+ timeout = INT64_MAX;
+
+ if (drm_intel_gem_bo_wait(fence->batch_bo, timeout) != 0)
+ return false;
+
+ fence->signalled = true;
+ drm_intel_bo_unreference(fence->batch_bo);
+ fence->batch_bo = NULL;
+
+ return true;
+}
+
+/**
+ * Return true if the function successfully signals or has already signalled.
+ * (This matches the behavior expected from __DRI2fence::client_wait_sync).
+ */
+static bool
+intel_fence_client_wait(struct intel_context *intel, struct intel_fence *fence,
+ uint64_t timeout)
+{
+ bool ret;
+
+ mtx_lock(&fence->mutex);
+ ret = intel_fence_client_wait_locked(intel, fence, timeout);
+ mtx_unlock(&fence->mutex);
+
+ return ret;
+}
+
+static void
+intel_fence_server_wait(struct intel_context *intel, struct intel_fence *fence)
+{
+ /* We have nothing to do for WaitSync. Our GL command stream is sequential,
+ * so given that the sync object has already flushed the batchbuffer, any
+ * batchbuffers coming after this waitsync will naturally not occur until
+ * the previous one is done.
+ */
+}
+
+static struct gl_sync_object *
+intel_gl_new_sync_object(struct gl_context *ctx)
+{
+ struct intel_gl_sync_object *sync;
+
+ sync = calloc(1, sizeof(*sync));
+ if (!sync)
+ return NULL;
+
+ return &sync->Base;
+}
+
+static void
+intel_gl_delete_sync_object(struct gl_context *ctx, struct gl_sync_object *s)
+{
+ struct intel_gl_sync_object *sync = (struct intel_gl_sync_object *)s;
+
+ intel_fence_finish(&sync->fence);
+ free(sync);
+}
+
+static void
+intel_gl_fence_sync(struct gl_context *ctx, struct gl_sync_object *s,
+ GLenum condition, GLbitfield flags)
+{
+ struct intel_context *intel = intel_context(ctx);
+ struct intel_gl_sync_object *sync = (struct intel_gl_sync_object *)s;
+
+ intel_fence_insert(intel, &sync->fence);
+}
+
+static void
+intel_gl_client_wait_sync(struct gl_context *ctx, struct gl_sync_object *s,
+ GLbitfield flags, GLuint64 timeout)
+{
+ struct intel_context *intel = intel_context(ctx);
+ struct intel_gl_sync_object *sync = (struct intel_gl_sync_object *)s;
+
+ if (intel_fence_client_wait(intel, &sync->fence, timeout))
+ s->StatusFlag = 1;
+}
+
+static void
+intel_gl_server_wait_sync(struct gl_context *ctx, struct gl_sync_object *s,
+ GLbitfield flags, GLuint64 timeout)
+{
+ struct intel_context *intel = intel_context(ctx);
+ struct intel_gl_sync_object *sync = (struct intel_gl_sync_object *)s;
+
+ intel_fence_server_wait(intel, &sync->fence);
+}
+
+static void
+intel_gl_check_sync(struct gl_context *ctx, struct gl_sync_object *s)
+{
+ struct intel_gl_sync_object *sync = (struct intel_gl_sync_object *)s;
+
+ if (intel_fence_has_completed(&sync->fence))
+ s->StatusFlag = 1;
+}
+
+void
+intel_init_syncobj_functions(struct dd_function_table *functions)
+{
+ functions->NewSyncObject = intel_gl_new_sync_object;
+ functions->DeleteSyncObject = intel_gl_delete_sync_object;
+ functions->FenceSync = intel_gl_fence_sync;
+ functions->CheckSync = intel_gl_check_sync;
+ functions->ClientWaitSync = intel_gl_client_wait_sync;
+ functions->ServerWaitSync = intel_gl_server_wait_sync;
+}
+
+static void *
+intel_dri_create_fence(__DRIcontext *ctx)
+{
+ struct intel_context *intel = ctx->driverPrivate;
+ struct intel_fence *fence;
+
+ fence = calloc(1, sizeof(*fence));
+ if (!fence)
+ return NULL;
+
+ mtx_init(&fence->mutex, mtx_plain);
+ fence->intel = intel;
+ intel_fence_insert(intel, fence);
+
+ return fence;
+}
+
+static void
+intel_dri_destroy_fence(__DRIscreen *screen, void *driver_fence)
+{
+ struct intel_fence *fence = driver_fence;
+
+ intel_fence_finish(fence);
+ free(fence);
+}
+
+static GLboolean
+intel_dri_client_wait_sync(__DRIcontext *ctx, void *driver_fence, unsigned flags,
+ uint64_t timeout)
+{
+ struct intel_fence *fence = driver_fence;
+
+ return intel_fence_client_wait(fence->intel, fence, timeout);
+}
+
+static void
+intel_dri_server_wait_sync(__DRIcontext *ctx, void *driver_fence, unsigned flags)
+{
+ struct intel_fence *fence = driver_fence;
+
+ /* We might be called here with a NULL fence as a result of WaitSyncKHR
+ * on a EGL_KHR_reusable_sync fence. Nothing to do here in such case.
+ */
+ if (!fence)
+ return;
+
+ intel_fence_server_wait(fence->intel, fence);
+}
+
+const __DRI2fenceExtension intelFenceExtension = {
+ .base = { __DRI2_FENCE, 1 },
+
+ .create_fence = intel_dri_create_fence,
+ .destroy_fence = intel_dri_destroy_fence,
+ .client_wait_sync = intel_dri_client_wait_sync,
+ .server_wait_sync = intel_dri_server_wait_sync,
+ .get_fence_from_cl_event = NULL,
+};