[Intel-gfx] [PATCH 2/3] drm/i915: Android sync points for i915 v3

Jesse Barnes jbarnes at virtuousgeek.org
Wed Dec 3 11:49:06 PST 2014


Expose an ioctl to create Android fences based on the Android sync point
infrastructure (which in turn is based on DMA-buf fences).  Just a
sketch at this point, no testing has been done.

There are a couple of goals here:
  1) allow applications and libraries to create fences without an
     associated buffer
  2) re-use a common API so userspace doesn't have to impedance mismatch
     between different driver implementations too much
  3) allow applications and libraries to use explicit synchronization if
     they choose by exposing fences directly

v2: use struct fence directly using Maarten's new interface
v3: use new i915 request structure (Jesse)
    make i915 fences a compile time option since Android support is still
    in staging (Jesse)
    check for request complete after arming IRQs (Chris)
    add timeline id to ioctl (Tvrtko)

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/Kconfig     |  14 ++
 drivers/gpu/drm/i915/Makefile    |   1 +
 drivers/gpu/drm/i915/i915_dma.c  |   5 +
 drivers/gpu/drm/i915/i915_drv.h  |  20 +++
 drivers/gpu/drm/i915/i915_gem.c  |   5 +
 drivers/gpu/drm/i915/i915_irq.c  |   4 +-
 drivers/gpu/drm/i915/i915_sync.c | 325 +++++++++++++++++++++++++++++++++++++++
 include/uapi/drm/i915_drm.h      |  23 +++
 8 files changed, 396 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/i915/i915_sync.c

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 4e39ab3..6b23d17 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -43,6 +43,20 @@ config DRM_I915_KMS
 
 	  If in doubt, say "Y".
 
+config DRM_I915_SYNC
+	bool "Enable explicit sync support"
+	depends on DRM_I915
+	default y
+	select STAGING
+	select ANDROID
+	select SYNC
+	help
+	  Choose this option to enable Android native sync support and the
+	  corresponding i915 driver code to expose it.  Slightly increases
+	  driver size and pulls in sync support from staging.
+
+	  If in doubt, say "Y".
+
 config DRM_I915_FBDEV
 	bool "Enable legacy fbdev support for the modesetting intel driver"
 	depends on DRM_I915
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index e4083e4..45e155f 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -56,6 +56,7 @@ i915-y += intel_audio.o \
 	  intel_sprite.o
 i915-$(CONFIG_ACPI)		+= intel_acpi.o intel_opregion.o
 i915-$(CONFIG_DRM_I915_FBDEV)	+= intel_fbdev.o
+i915-$(CONFIG_DRM_I915_SYNC)	+= i915_sync.o
 
 # modesetting output/encoder code
 i915-y += dvo_ch7017.o \
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 887d88f..621bd7f 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1062,6 +1062,11 @@ const struct drm_ioctl_desc i915_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(I915_REG_READ, i915_reg_read_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(I915_GET_RESET_STATS, i915_get_reset_stats_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(I915_GEM_USERPTR, i915_gem_userptr_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
+#ifdef CONFIG_DRM_I915_SYNC
+	DRM_IOCTL_DEF_DRV(I915_GEM_FENCE, i915_sync_create_fence_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
+#else
+	DRM_IOCTL_DEF_DRV(I915_GEM_FENCE, drm_noop, DRM_UNLOCKED|DRM_RENDER_ALLOW),
+#endif
 };
 
 int i915_max_ioctl = ARRAY_SIZE(i915_ioctls);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 049482f..367d95a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1525,6 +1525,9 @@ struct i915_workarounds {
 	u32 count;
 };
 
+struct i915_sync_timeline;
+
+
 struct drm_i915_private {
 	struct drm_device *dev;
 	struct kmem_cache *slab;
@@ -1560,6 +1563,9 @@ struct drm_i915_private {
 	uint32_t last_seqno, next_seqno;
 
 	struct drm_dma_handle *status_page_dmah;
+
+	struct i915_sync_timeline *sync_tl[I915_NUM_RINGS];
+
 	struct resource mch_res;
 
 	/* protects the irq masks */
@@ -2509,6 +2515,20 @@ void i915_init_vm(struct drm_i915_private *dev_priv,
 void i915_gem_free_object(struct drm_gem_object *obj);
 void i915_gem_vma_destroy(struct i915_vma *vma);
 
+/* i915_sync.c */
+#ifdef CONFIG_DRM_I915_SYNC
+int i915_sync_init(struct drm_i915_private *dev_priv);
+void i915_sync_fini(struct drm_i915_private *dev_priv);
+int i915_sync_create_fence_ioctl(struct drm_device *dev, void *data,
+				 struct drm_file *file);
+#else
+static inline int i915_sync_init(struct drm_i915_private *dev_priv)
+{
+	return 0;
+}
+static inline void i915_sync_fini(struct drm_i915_private *dev_priv) { }
+#endif
+
 #define PIN_MAPPABLE 0x1
 #define PIN_NONBLOCK 0x2
 #define PIN_GLOBAL 0x4
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7a83a9f..39407b4 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4887,6 +4887,9 @@ int i915_gem_init(struct drm_device *dev)
 		atomic_set_mask(I915_WEDGED, &dev_priv->gpu_error.reset_counter);
 		ret = 0;
 	}
+
+	i915_sync_init(dev_priv);
+
 	mutex_unlock(&dev->struct_mutex);
 
 	return ret;
@@ -5011,6 +5014,8 @@ void i915_gem_release(struct drm_device *dev, struct drm_file *file)
 		request->file_priv = NULL;
 	}
 	spin_unlock(&file_priv->mm.lock);
+
+	i915_sync_fini(dev->dev_private);
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 7913a72..d4ede83 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -33,6 +33,7 @@
 #include <linux/circ_buf.h>
 #include <drm/drmP.h>
 #include <drm/i915_drm.h>
+#include "../../../staging/android/sync.h"
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
@@ -2378,8 +2379,9 @@ static void i915_error_wake_up(struct drm_i915_private *dev_priv,
 	 */
 
 	/* Wake up __wait_seqno, potentially holding dev->struct_mutex. */
-	for_each_ring(ring, dev_priv, i)
+	for_each_ring(ring, dev_priv, i) {
 		wake_up_all(&ring->irq_queue);
+	}
 
 	/* Wake up intel_crtc_wait_for_pending_flips, holding crtc->mutex. */
 	wake_up_all(&dev_priv->pending_flip_queue);
diff --git a/drivers/gpu/drm/i915/i915_sync.c b/drivers/gpu/drm/i915/i915_sync.c
new file mode 100644
index 0000000..4741b0c
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_sync.c
@@ -0,0 +1,325 @@
+/*
+ * Copyright © 2014 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:
+ *    Jesse Barnes <jbarnes at virtuousgeek.org>
+ *
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_vma_manager.h>
+#include <drm/i915_drm.h>
+#include "i915_drv.h"
+#include "i915_trace.h"
+#include "intel_drv.h"
+#include <linux/oom.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/pci.h>
+#include <linux/dma-buf.h>
+#include "../../../staging/android/sync.h"
+
+/* Nothing really to protect here... */
+static spinlock_t fence_lock;
+
+/*
+ * i915 fences on sync timelines
+ *
+ * We implement sync points in terms of i915 seqnos.  They're exposed
+ * through the new DRM_I915_GEM_FENCE ioctl, and can be mixed and matched
+ * with other Android timelines and aggregated into sync_fences, etc.
+ *
+ * TODO:
+ *   rebase on top of Chris's seqno/request stuff and use requests
+ *   allow non-RCS fences (need ring/context association)
+ */
+
+struct i915_fence {
+	struct fence base;
+	struct intel_engine_cs *ring;
+	struct intel_context *ctx;
+	wait_queue_t wait;
+	struct drm_i915_gem_request *request;
+};
+
+#define to_intel_fence(x) container_of(x, struct i915_fence, base)
+
+int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
+		 unsigned reset_counter,
+		 bool interruptible,
+		 struct timespec *timeout,
+		 struct drm_i915_file_private *file_priv);
+
+static const char *i915_fence_get_driver_name(struct fence *fence)
+{
+	return "i915";
+}
+
+static const char *i915_fence_get_timeline_name(struct fence *fence)
+{
+	struct i915_fence *intel_fence = to_intel_fence(fence);
+
+	return intel_fence->ring->name;
+}
+
+static int i915_fence_check(wait_queue_t *wait, unsigned mode, int flags,
+			    void *key)
+{
+	struct i915_fence *intel_fence = wait->private;
+	struct intel_engine_cs *ring = intel_fence->ring;
+
+	if (!i915_gem_request_completed(intel_fence->request, false))
+		return 0;
+
+	fence_signal_locked(&intel_fence->base);
+
+	__remove_wait_queue(&ring->irq_queue, wait);
+	fence_put(&intel_fence->base);
+	ring->irq_put(ring);
+
+	return 0;
+}
+
+static bool i915_fence_enable_signaling(struct fence *fence)
+{
+	struct i915_fence *intel_fence = to_intel_fence(fence);
+	struct intel_engine_cs *ring = intel_fence->ring;
+	struct drm_i915_private *dev_priv = ring->dev->dev_private;
+	wait_queue_t *wait = &intel_fence->wait;
+
+	/* queue fence wait queue on irq queue and get fence */
+	if (i915_gem_request_completed(intel_fence->request, false) ||
+	    i915_terminally_wedged(&dev_priv->gpu_error))
+		return false;
+
+	if (!ring->irq_get(ring))
+		return false;
+
+	if (i915_gem_request_completed(intel_fence->request, false)) {
+		ring->irq_put(ring);
+		return true;
+	}
+
+	wait->flags = 0;
+	wait->private = intel_fence;
+	wait->func = i915_fence_check;
+
+	__add_wait_queue(&ring->irq_queue, wait);
+	fence_get(fence);
+
+	return true;
+}
+
+static bool i915_fence_signaled(struct fence *fence)
+{
+	struct i915_fence *intel_fence = to_intel_fence(fence);
+
+	return i915_gem_request_completed(intel_fence->request, false);
+}
+
+static signed long i915_fence_wait(struct fence *fence, bool intr,
+				   signed long timeout_js)
+{
+	struct i915_fence *intel_fence = to_intel_fence(fence);
+	struct drm_i915_private *dev_priv = intel_fence->ring->dev->dev_private;
+	int ret;
+	s64 timeout;
+
+	timeout = jiffies_to_nsecs(timeout_js);
+
+	ret = __i915_wait_request(intel_fence->request,
+				  atomic_read(&dev_priv->gpu_error.reset_counter),
+				  intr, &timeout, NULL);
+	if (ret == -ETIME)
+		return nsecs_to_jiffies(timeout);
+
+	return ret;
+}
+
+static int i915_fence_fill_driver_data(struct fence *fence, void *data,
+				      int size)
+{
+	struct i915_fence *intel_fence = to_intel_fence(fence);
+
+	if (size < sizeof(intel_fence->request->seqno))
+		return -ENOMEM;
+
+	memcpy(data, &intel_fence->request->seqno,
+	       sizeof(intel_fence->request->seqno));
+
+	return sizeof(intel_fence->request->seqno);
+}
+
+static void i915_fence_value_str(struct fence *fence, char *str, int size)
+{
+	struct i915_fence *intel_fence = to_intel_fence(fence);
+
+	snprintf(str, size, "%u", intel_fence->request->seqno);
+}
+
+static void i915_fence_timeline_value_str(struct fence *fence, char *str,
+					  int size)
+{
+	struct i915_fence *intel_fence = to_intel_fence(fence);
+	struct intel_engine_cs *ring = intel_fence->ring;
+
+	snprintf(str, size, "%u", ring->get_seqno(ring, false));
+}
+
+static struct fence_ops i915_fence_ops = {
+	.get_driver_name = 	i915_fence_get_driver_name,
+	.get_timeline_name =	i915_fence_get_timeline_name,
+	.enable_signaling =	i915_fence_enable_signaling,
+	.signaled =		i915_fence_signaled,
+	.wait =			i915_fence_wait,
+	.fill_driver_data =	i915_fence_fill_driver_data,
+	.fence_value_str =	i915_fence_value_str,
+	.timeline_value_str =	i915_fence_timeline_value_str,
+};
+
+static struct fence *i915_fence_create(struct intel_engine_cs *ring,
+				       struct intel_context *ctx)
+{
+	struct i915_fence *fence;
+	int ret;
+
+	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+	if (!fence)
+		return NULL;
+
+	ret = ring->add_request(ring);
+	if (ret) {
+		DRM_ERROR("add_request failed\n");
+		fence_free((struct fence *)fence);
+		return NULL;
+	}
+
+	fence->ring = ring;
+	fence->ctx = ctx;
+	fence->request = ring->outstanding_lazy_request;
+	fence_init(&fence->base, &i915_fence_ops, &fence_lock, ctx->user_handle,
+		   fence->request->seqno);
+
+	return &fence->base;
+}
+
+/**
+ * i915_sync_create_fence_ioctl - fence creation function
+ * @dev: drm device
+ * @data: ioctl data
+ * @file: file struct
+ *
+ * This function creates a fence given a context and ring, and returns
+ * it to the caller in the form of a file descriptor.
+ *
+ * The returned descriptor is a sync fence fd, and can be used with all
+ * the usual sync fence operations (poll, ioctl, etc).
+ *
+ * The process fd limit should prevent an overallocation of fence objects,
+ * which need to be destroyed manually with a close() call.
+ */
+int i915_sync_create_fence_ioctl(struct drm_device *dev, void *data,
+				 struct drm_file *file)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_gem_fence *fdata = data;
+	struct fence *fence;
+	struct sync_fence *sfence;
+	struct intel_engine_cs *ring;
+	struct intel_context *ctx;
+	u32 ctx_id = fdata->ctx_id;
+	int fd = get_unused_fd_flags(O_CLOEXEC);
+	int ret = 0;
+
+	if (file == NULL) {
+		DRM_ERROR("no file priv?\n");
+		return -EINVAL;
+	}
+
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret) {
+		DRM_ERROR("mutex interrupted\n");
+		goto out;
+	}
+
+	ctx = i915_gem_context_get(file->driver_priv, ctx_id);
+	if (ctx == NULL) {
+		DRM_ERROR("context lookup failed\n");
+		ret = -ENOENT;
+		goto err;
+	}
+
+	ring = &dev_priv->ring[RCS];
+
+	if (!intel_ring_initialized(ring)) {
+		DRM_ERROR("ring not ready\n");
+		ret = -EIO;
+		goto err;
+	}
+
+	fence = i915_fence_create(ring, ctx);
+	if (!fence) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	fdata->name[sizeof(fdata->name) - 1] = '\0';
+	sfence = sync_fence_create_dma(fdata->name, fence);
+	if (!sfence) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	fdata->fd = fd;
+
+	sync_fence_install(sfence, fd);
+
+	mutex_unlock(&dev->struct_mutex);
+out:
+	return ret;
+
+err:
+	mutex_unlock(&dev->struct_mutex);
+	put_unused_fd(fd);
+	return ret;
+}
+
+int i915_sync_init(struct drm_i915_private *dev_priv)
+{
+	struct intel_engine_cs *ring;
+	int i, ret = 0;
+
+	for_each_ring(ring, dev_priv, i) {
+		/* FIXME: non-RCS fences */
+	}
+
+	return ret;
+}
+
+void i915_sync_fini(struct drm_i915_private *dev_priv)
+{
+	int i;
+
+	for (i = 0; i < I915_NUM_RINGS; i++) {
+	}
+}
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 2502622..3127990 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -224,6 +224,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_REG_READ		0x31
 #define DRM_I915_GET_RESET_STATS	0x32
 #define DRM_I915_GEM_USERPTR		0x33
+#define DRM_I915_GEM_FENCE		0x34
 
 #define DRM_IOCTL_I915_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
 #define DRM_IOCTL_I915_FLUSH		DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -275,6 +276,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_REG_READ			DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_REG_READ, struct drm_i915_reg_read)
 #define DRM_IOCTL_I915_GET_RESET_STATS		DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GET_RESET_STATS, struct drm_i915_reset_stats)
 #define DRM_IOCTL_I915_GEM_USERPTR			DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_USERPTR, struct drm_i915_gem_userptr)
+#define DRM_IOCTL_I915_GEM_FENCE			DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_FENCE, struct drm_i915_gem_fence)
 
 /* Allow drivers to submit batchbuffers directly to hardware, relying
  * on the security mechanisms provided by hardware.
@@ -1073,4 +1075,25 @@ struct drm_i915_gem_userptr {
 	__u32 handle;
 };
 
+/**
+ * drm_i915_gem_fence - create a fence
+ * @fd: fd for fence
+ * @ctx_id: context ID for fence
+ * @flags: flags for operation
+ *
+ * Creates a fence in @fd and returns it to the caller.  This fd can be
+ * passed around between processes as any other fd, and can be poll'd
+ * and read for status.
+ *
+ * RETURNS:
+ * A valid fd in the @fd field or an errno on error.
+ */
+struct drm_i915_gem_fence {
+	__s32 fd;
+	__u32 ctx_id;
+	__u32 timeline_id;
+	__u32 flags;
+	char name[32];
+};
+
 #endif /* _UAPI_I915_DRM_H_ */
-- 
1.9.1




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