Add Linux completion API and use it.

ok jsg@

5 files changed, 65 insertions, 34 deletions

diff --git a/sys/dev/pci/drm/drm_linux.h b/sys/dev/pci/drm/drm_linux.h
index 514de9b75d1..34750f93305 100644
--- a/sys/dev/pci/drm/drm_linux.h
+++ b/sys/dev/pci/drm/drm_linux.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: drm_linux.h,v 1.30 2015/06/24 19:01:51 kettenis Exp $	*/
+/*	$OpenBSD: drm_linux.h,v 1.31 2015/06/26 15:22:23 kettenis Exp $	*/
 /*
  * Copyright (c) 2013, 2014 Mark Kettenis
  *
@@ -281,6 +281,46 @@ init_waitqueue_head(wait_queue_head_t *wq)
 #define wake_up_all(x)			wakeup(x)
 #define wake_up_all_locked(x)		wakeup(x)
 
+struct completion {
+	u_int done;
+	wait_queue_head_t wait;
+};
+
+#define INIT_COMPLETION(x) ((x).done = 0)
+
+static inline void
+init_completion(struct completion *x)
+{
+	x->done = 0;
+	mtx_init(&x->wait.lock, IPL_NONE);
+}
+
+static inline u_long
+wait_for_completion_interruptible_timeout(struct completion *x, u_long timo)
+{
+	int ret;
+
+	mtx_enter(&x->wait.lock);
+	while (x->done == 0) {
+		ret = msleep(x, &x->wait.lock, PCATCH, "wfcit", timo);
+		if (ret) {
+			mtx_leave(&x->wait.lock);
+			return (ret == EWOULDBLOCK) ? 0 : -ret;
+		}
+	}
+
+	return 1;
+}
+
+static inline void
+complete_all(struct completion *x)
+{
+	mtx_enter(&x->wait.lock);
+	x->done = 1;
+	mtx_leave(&x->wait.lock);
+	wakeup(x);
+}
+
 struct workqueue_struct;
 
 struct work_struct {
diff --git a/sys/dev/pci/drm/i915/i915_drv.c b/sys/dev/pci/drm/i915/i915_drv.c
index d897b6d7046..85a2268a294 100644
--- a/sys/dev/pci/drm/i915/i915_drv.c
+++ b/sys/dev/pci/drm/i915/i915_drv.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: i915_drv.c,v 1.84 2015/06/24 08:32:39 kettenis Exp $ */
+/* $OpenBSD: i915_drv.c,v 1.85 2015/06/26 15:22:23 kettenis Exp $ */
 /*
  * Copyright (c) 2008-2009 Owain G. Ainsworth <oga@openbsd.org>
  *
@@ -929,7 +929,6 @@ inteldrm_attach(struct device *parent, struct device *self, void *aux)
 	mtx_init(&dev_priv->dpio_lock, IPL_TTY);
 	mtx_init(&dev_priv->gt_lock, IPL_TTY);
 	mtx_init(&mchdev_lock, IPL_TTY);
-	mtx_init(&dev_priv->error_completion_lock, IPL_NONE);
 	rw_init(&dev_priv->rps.hw_lock, "rpshw");
 
 	task_set(&dev_priv->switchtask, inteldrm_doswitch, dev_priv);
@@ -988,7 +987,6 @@ inteldrm_attach(struct device *parent, struct device *self, void *aux)
 	timeout_set(&dev_priv->hangcheck_timer, i915_hangcheck_elapsed, dev_priv);
 	dev_priv->next_seqno = 1;
 	dev_priv->mm.suspended = 1;
-	dev_priv->error_completion = 0;
 
 	if (pci_find_device(&bpa, inteldrm_gmch_match) == 0) {
 		printf(": can't find GMCH\n");
diff --git a/sys/dev/pci/drm/i915/i915_drv.h b/sys/dev/pci/drm/i915/i915_drv.h
index 55a80060ec9..4ed99ad83b4 100644
--- a/sys/dev/pci/drm/i915/i915_drv.h
+++ b/sys/dev/pci/drm/i915/i915_drv.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: i915_drv.h,v 1.65 2015/06/24 17:59:42 kettenis Exp $ */
+/* $OpenBSD: i915_drv.h,v 1.66 2015/06/26 15:22:23 kettenis Exp $ */
 /* i915_drv.h -- Private header for the I915 driver -*- linux-c -*-
  */
 /*
@@ -816,8 +816,7 @@ struct inteldrm_softc {
 	/* Protected by dev->error_lock. */
 	struct drm_i915_error_state *first_error;
 	struct work_struct error_work;
-	int error_completion;
-	struct mutex error_completion_lock;
+	struct completion error_completion;
 	struct workqueue_struct *wq;
 
 	/* number of ioctls + faults in flight */
diff --git a/sys/dev/pci/drm/i915/i915_gem.c b/sys/dev/pci/drm/i915/i915_gem.c
index 283361adc6a..e4edc6581af 100644
--- a/sys/dev/pci/drm/i915/i915_gem.c
+++ b/sys/dev/pci/drm/i915/i915_gem.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: i915_gem.c,v 1.97 2015/06/24 17:59:42 kettenis Exp $	*/
+/*	$OpenBSD: i915_gem.c,v 1.98 2015/06/26 15:22:23 kettenis Exp $	*/
 /*
  * Copyright (c) 2008-2009 Owain G. Ainsworth <oga@openbsd.org>
  *
@@ -110,6 +110,8 @@ static int
 i915_gem_wait_for_error(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct completion *x = &dev_priv->error_completion;
+	unsigned long flags;
 	int ret;
 
 	if (!atomic_read(&dev_priv->mm.wedged))
@@ -120,16 +122,13 @@ i915_gem_wait_for_error(struct drm_device *dev)
 	 * userspace. If it takes that long something really bad is going on and
 	 * we should simply try to bail out and fail as gracefully as possible.
 	 */
-	mtx_enter(&dev_priv->error_completion_lock);
-	while (dev_priv->error_completion == 0) {
-		ret = -msleep(&dev_priv->error_completion,
-		    &dev_priv->error_completion_lock, PCATCH, "915wco", 10*hz);
-		if (ret) {
-			mtx_leave(&dev_priv->error_completion_lock);
-			return ret;
-		}
+	ret = wait_for_completion_interruptible_timeout(x, 10*HZ);
+	if (ret == 0) {
+		DRM_ERROR("Timed out waiting for the gpu reset to complete\n");
+		return -EIO;
+	} else if (ret < 0) {
+		return ret;
 	}
-	mtx_leave(&dev_priv->error_completion_lock);
 
 	if (atomic_read(&dev_priv->mm.wedged)) {
 		/* GPU is hung, bump the completion count to account for
@@ -137,9 +136,9 @@ i915_gem_wait_for_error(struct drm_device *dev)
 		 * end up waiting upon a subsequent completion event that
 		 * will never happen.
 		 */
-		mtx_enter(&dev_priv->error_completion_lock);
-		dev_priv->error_completion++;
-		mtx_leave(&dev_priv->error_completion_lock);
+		spin_lock_irqsave(&x->wait.lock, flags);
+		x->done++;
+		spin_unlock_irqrestore(&x->wait.lock, flags);
 	}
 	return 0;
 }
@@ -978,13 +977,15 @@ i915_gem_check_wedge(struct drm_i915_private *dev_priv,
 		     bool interruptible)
 {
 	if (atomic_read(&dev_priv->mm.wedged)) {
+		struct completion *x = &dev_priv->error_completion;
 		bool recovery_complete;
+		unsigned long flags;
 
 		/* Give the error handler a chance to run. */
-		mtx_enter(&dev_priv->error_completion_lock);
-		recovery_complete = dev_priv->error_completion > 0;
-		mtx_leave(&dev_priv->error_completion_lock);
-		
+		spin_lock_irqsave(&x->wait.lock, flags);
+		recovery_complete = x->done > 0;
+		spin_unlock_irqrestore(&x->wait.lock, flags);
+
 		/* Non-interruptible callers can't handle -EAGAIN, hence return
 		 * -EIO unconditionally for these. */
 		if (!interruptible)
@@ -4309,11 +4310,7 @@ i915_gem_load(struct drm_device *dev)
 		INIT_LIST_HEAD(&dev_priv->fence_regs[i].lru_list);
 	INIT_DELAYED_WORK(&dev_priv->mm.retire_work,
 			  i915_gem_retire_work_handler);
-#if 0
 	init_completion(&dev_priv->error_completion);
-#else
-	dev_priv->error_completion = 0;
-#endif
 
 	/* On GEN3 we really need to make sure the ARB C3 LP bit is set */
 	if (IS_GEN3(dev)) {
diff --git a/sys/dev/pci/drm/i915/i915_irq.c b/sys/dev/pci/drm/i915/i915_irq.c
index d985103e437..24e39a5dfc4 100644
--- a/sys/dev/pci/drm/i915/i915_irq.c
+++ b/sys/dev/pci/drm/i915/i915_irq.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: i915_irq.c,v 1.26 2015/06/24 08:32:39 kettenis Exp $	*/
+/*	$OpenBSD: i915_irq.c,v 1.27 2015/06/26 15:22:23 kettenis Exp $	*/
 /* i915_irq.c -- IRQ support for the I915 -*- linux-c -*-
  */
 /*
@@ -858,10 +858,7 @@ static void i915_error_work_func(struct work_struct *work)
 			atomic_set(&dev_priv->mm.wedged, 0);
 //			kobject_uevent_env(&dev->primary->kdev.kobj, KOBJ_CHANGE, reset_done_event);
 		}
-		mtx_enter(&dev_priv->error_completion_lock);
-		dev_priv->error_completion++;
-		wakeup(&dev_priv->error_completion);
-		mtx_leave(&dev_priv->error_completion_lock);
+		complete_all(&dev_priv->error_completion);
 	}
 }
 
@@ -1466,7 +1463,7 @@ void i915_handle_error(struct drm_device *dev, bool wedged)
 	i915_report_and_clear_eir(dev);
 
 	if (wedged) {
-//		INIT_COMPLETION(dev_priv->error_completion);
+		INIT_COMPLETION(dev_priv->error_completion);
 		atomic_set(&dev_priv->mm.wedged, 1);
 
 		/*