1 files changed, 163 insertions, 198 deletions

diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c
index a5dbf1ba4645..acc7d82e0585 100644
--- a/drivers/gpu/host1x/syncpt.c
+++ b/drivers/gpu/host1x/syncpt.c
@@ -1,23 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Tegra host1x Syncpoints
  *
  * Copyright (c) 2010-2015, NVIDIA Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <linux/module.h>
 #include <linux/device.h>
+#include <linux/dma-fence.h>
 #include <linux/slab.h>
 
 #include <trace/events/host1x.h>
@@ -53,17 +43,32 @@ static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
 		base->requested = false;
 }
 
-static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
-						 struct host1x_client *client,
-						 unsigned long flags)
+/**
+ * host1x_syncpt_alloc() - allocate a syncpoint
+ * @host: host1x device data
+ * @flags: bitfield of HOST1X_SYNCPT_* flags
+ * @name: name for the syncpoint for use in debug prints
+ *
+ * Allocates a hardware syncpoint for the caller's use. The caller then has
+ * the sole authority to mutate the syncpoint's value until it is freed again.
+ *
+ * If no free syncpoints are available, or a NULL name was specified, returns
+ * NULL.
+ */
+struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
+					  unsigned long flags,
+					  const char *name)
 {
 	struct host1x_syncpt *sp = host->syncpt;
+	char *full_name;
 	unsigned int i;
-	char *name;
+
+	if (!name)
+		return NULL;
 
 	mutex_lock(&host->syncpt_mutex);
 
-	for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
+	for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
 		;
 
 	if (i >= host->info->nb_pts)
@@ -75,19 +80,19 @@ static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
 			goto unlock;
 	}
 
-	name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
-			 client ? dev_name(client->dev) : NULL);
-	if (!name)
+	full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name);
+	if (!full_name)
 		goto free_base;
 
-	sp->client = client;
-	sp->name = name;
+	sp->name = full_name;
 
 	if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
 		sp->client_managed = true;
 	else
 		sp->client_managed = false;
 
+	kref_init(&sp->ref);
+
 	mutex_unlock(&host->syncpt_mutex);
 	return sp;
 
@@ -98,6 +103,7 @@ unlock:
 	mutex_unlock(&host->syncpt_mutex);
 	return NULL;
 }
+EXPORT_SYMBOL(host1x_syncpt_alloc);
 
 /**
  * host1x_syncpt_id() - retrieve syncpoint ID
@@ -132,12 +138,21 @@ void host1x_syncpt_restore(struct host1x *host)
 	struct host1x_syncpt *sp_base = host->syncpt;
 	unsigned int i;
 
-	for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
+	for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
+		/*
+		 * Unassign syncpt from channels for purposes of Tegra186
+		 * syncpoint protection. This prevents any channel from
+		 * accessing it until it is reassigned.
+		 */
+		host1x_hw_syncpt_assign_to_channel(host, sp_base + i, NULL);
 		host1x_hw_syncpt_restore(host, sp_base + i);
+	}
 
 	for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 		host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
 
+	host1x_hw_syncpt_enable_protection(host);
+
 	wmb();
 }
 
@@ -195,17 +210,6 @@ int host1x_syncpt_incr(struct host1x_syncpt *sp)
 }
 EXPORT_SYMBOL(host1x_syncpt_incr);
 
-/*
- * Updated sync point form hardware, and returns true if syncpoint is expired,
- * false if we may need to wait
- */
-static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
-{
-	host1x_hw_syncpt_load(sp->host, sp);
-
-	return host1x_syncpt_is_expired(sp, thresh);
-}
-
 /**
  * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
  * @sp: host1x syncpoint
@@ -216,99 +220,46 @@ static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 		       u32 *value)
 {
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
-	void *ref;
-	struct host1x_waitlist *waiter;
-	int err = 0, check_count = 0;
-	u32 val;
+	struct dma_fence *fence;
+	long wait_err;
 
-	if (value)
-		*value = 0;
+	host1x_hw_syncpt_load(sp->host, sp);
 
-	/* first check cache */
-	if (host1x_syncpt_is_expired(sp, thresh)) {
-		if (value)
-			*value = host1x_syncpt_load(sp);
+	if (value)
+		*value = host1x_syncpt_load(sp);
 
+	if (host1x_syncpt_is_expired(sp, thresh))
 		return 0;
-	}
-
-	/* try to read from register */
-	val = host1x_hw_syncpt_load(sp->host, sp);
-	if (host1x_syncpt_is_expired(sp, thresh)) {
-		if (value)
-			*value = val;
-
-		goto done;
-	}
-
-	if (!timeout) {
-		err = -EAGAIN;
-		goto done;
-	}
 
-	/* allocate a waiter */
-	waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
-	if (!waiter) {
-		err = -ENOMEM;
-		goto done;
-	}
-
-	/* schedule a wakeup when the syncpoint value is reached */
-	err = host1x_intr_add_action(sp->host, sp, thresh,
-				     HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
-				     &wq, waiter, &ref);
-	if (err)
-		goto done;
-
-	err = -EAGAIN;
-	/* Caller-specified timeout may be impractically low */
 	if (timeout < 0)
 		timeout = LONG_MAX;
+	else if (timeout == 0)
+		return -EAGAIN;
 
-	/* wait for the syncpoint, or timeout, or signal */
-	while (timeout) {
-		long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
-		int remain;
-
-		remain = wait_event_interruptible_timeout(wq,
-				syncpt_load_min_is_expired(sp, thresh),
-				check);
-		if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
-			if (value)
-				*value = host1x_syncpt_load(sp);
+	fence = host1x_fence_create(sp, thresh, false);
+	if (IS_ERR(fence))
+		return PTR_ERR(fence);
 
-			err = 0;
-
-			break;
-		}
-
-		if (remain < 0) {
-			err = remain;
-			break;
-		}
+	wait_err = dma_fence_wait_timeout(fence, true, timeout);
+	if (wait_err == 0)
+		host1x_fence_cancel(fence);
+	dma_fence_put(fence);
 
-		timeout -= check;
-
-		if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
-			dev_warn(sp->host->dev,
-				"%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
-				 current->comm, sp->id, sp->name,
-				 thresh, timeout);
-
-			host1x_debug_dump_syncpts(sp->host);
-
-			if (check_count == MAX_STUCK_CHECK_COUNT)
-				host1x_debug_dump(sp->host);
-
-			check_count++;
-		}
-	}
-
-	host1x_intr_put_ref(sp->host, sp->id, ref);
+	if (value)
+		*value = host1x_syncpt_load(sp);
 
-done:
-	return err;
+	/*
+	 * Don't rely on dma_fence_wait_timeout return value,
+	 * since it returns zero both on timeout and if the
+	 * wait completed with 0 jiffies left.
+	 */
+	host1x_hw_syncpt_load(sp->host, sp);
+	if (wait_err == 0 && !host1x_syncpt_is_expired(sp, thresh))
+		return -EAGAIN;
+	else if (wait_err < 0)
+		return wait_err;
+	else
+		return 0;
 }
 EXPORT_SYMBOL(host1x_syncpt_wait);
 
@@ -318,59 +269,12 @@ EXPORT_SYMBOL(host1x_syncpt_wait);
 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
 {
 	u32 current_val;
-	u32 future_val;
 
 	smp_rmb();
 
 	current_val = (u32)atomic_read(&sp->min_val);
-	future_val = (u32)atomic_read(&sp->max_val);
-
-	/* Note the use of unsigned arithmetic here (mod 1<<32).
-	 *
-	 * c = current_val = min_val	= the current value of the syncpoint.
-	 * t = thresh			= the value we are checking
-	 * f = future_val  = max_val	= the value c will reach when all
-	 *				  outstanding increments have completed.
-	 *
-	 * Note that c always chases f until it reaches f.
-	 *
-	 * Dtf = (f - t)
-	 * Dtc = (c - t)
-	 *
-	 *  Consider all cases:
-	 *
-	 *	A) .....c..t..f.....	Dtf < Dtc	need to wait
-	 *	B) .....c.....f..t..	Dtf > Dtc	expired
-	 *	C) ..t..c.....f.....	Dtf > Dtc	expired	   (Dct very large)
-	 *
-	 *  Any case where f==c: always expired (for any t).	Dtf == Dcf
-	 *  Any case where t==c: always expired (for any f).	Dtf >= Dtc (because Dtc==0)
-	 *  Any case where t==f!=c: always wait.		Dtf <  Dtc (because Dtf==0,
-	 *							Dtc!=0)
-	 *
-	 *  Other cases:
-	 *
-	 *	A) .....t..f..c.....	Dtf < Dtc	need to wait
-	 *	A) .....f..c..t.....	Dtf < Dtc	need to wait
-	 *	A) .....f..t..c.....	Dtf > Dtc	expired
-	 *
-	 *   So:
-	 *	   Dtf >= Dtc implies EXPIRED	(return true)
-	 *	   Dtf <  Dtc implies WAIT	(return false)
-	 *
-	 * Note: If t is expired then we *cannot* wait on it. We would wait
-	 * forever (hang the system).
-	 *
-	 * Note: do NOT get clever and remove the -thresh from both sides. It
-	 * is NOT the same.
-	 *
-	 * If future valueis zero, we have a client managed sync point. In that
-	 * case we do a direct comparison.
-	 */
-	if (!host1x_syncpt_client_managed(sp))
-		return future_val - thresh >= current_val - thresh;
-	else
-		return (s32)(current_val - thresh) >= 0;
+
+	return ((current_val - thresh) & 0x80000000U) == 0U;
 }
 
 int host1x_syncpt_init(struct host1x *host)
@@ -392,13 +296,6 @@ int host1x_syncpt_init(struct host1x *host)
 	for (i = 0; i < host->info->nb_pts; i++) {
 		syncpt[i].id = i;
 		syncpt[i].host = host;
-
-		/*
-		 * Unassign syncpt from channels for purposes of Tegra186
-		 * syncpoint protection. This prevents any channel from
-		 * accessing it until it is reassigned.
-		 */
-		host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL);
 	}
 
 	for (i = 0; i < host->info->nb_bases; i++)
@@ -408,14 +305,16 @@ int host1x_syncpt_init(struct host1x *host)
 	host->syncpt = syncpt;
 	host->bases = bases;
 
-	host1x_syncpt_restore(host);
-	host1x_hw_syncpt_enable_protection(host);
-
 	/* Allocate sync point to use for clearing waits for expired fences */
-	host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
+	host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
 	if (!host->nop_sp)
 		return -ENOMEM;
 
+	if (host->info->reserve_vblank_syncpts) {
+		kref_init(&host->syncpt[26].ref);
+		kref_init(&host->syncpt[27].ref);
+	}
+
 	return 0;
 }
 
@@ -427,44 +326,50 @@ int host1x_syncpt_init(struct host1x *host)
  * host1x client drivers can use this function to allocate a syncpoint for
  * subsequent use. A syncpoint returned by this function will be reserved for
  * use by the client exclusively. When no longer using a syncpoint, a host1x
- * client driver needs to release it using host1x_syncpt_free().
+ * client driver needs to release it using host1x_syncpt_put().
  */
 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 					    unsigned long flags)
 {
-	struct host1x *host = dev_get_drvdata(client->parent->parent);
+	struct host1x *host = dev_get_drvdata(client->host->parent);
 
-	return host1x_syncpt_alloc(host, client, flags);
+	return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
 }
 EXPORT_SYMBOL(host1x_syncpt_request);
 
-/**
- * host1x_syncpt_free() - free a requested syncpoint
- * @sp: host1x syncpoint
- *
- * Release a syncpoint previously allocated using host1x_syncpt_request(). A
- * host1x client driver should call this when the syncpoint is no longer in
- * use. Note that client drivers must ensure that the syncpoint doesn't remain
- * under the control of hardware after calling this function, otherwise two
- * clients may end up trying to access the same syncpoint concurrently.
- */
-void host1x_syncpt_free(struct host1x_syncpt *sp)
+static void syncpt_release(struct kref *ref)
 {
-	if (!sp)
-		return;
+	struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
+
+	atomic_set(&sp->max_val, host1x_syncpt_read(sp));
 
-	mutex_lock(&sp->host->syncpt_mutex);
+	sp->locked = false;
 
 	host1x_syncpt_base_free(sp->base);
 	kfree(sp->name);
 	sp->base = NULL;
-	sp->client = NULL;
 	sp->name = NULL;
 	sp->client_managed = false;
 
 	mutex_unlock(&sp->host->syncpt_mutex);
 }
-EXPORT_SYMBOL(host1x_syncpt_free);
+
+/**
+ * host1x_syncpt_put() - free a requested syncpoint
+ * @sp: host1x syncpoint
+ *
+ * Release a syncpoint previously allocated using host1x_syncpt_request(). A
+ * host1x client driver should call this when the syncpoint is no longer in
+ * use.
+ */
+void host1x_syncpt_put(struct host1x_syncpt *sp)
+{
+	if (!sp)
+		return;
+
+	kref_put_mutex(&sp->ref, syncpt_release, &sp->host->syncpt_mutex);
+}
+EXPORT_SYMBOL(host1x_syncpt_put);
 
 void host1x_syncpt_deinit(struct host1x *host)
 {
@@ -531,16 +436,48 @@ unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
 }
 
 /**
- * host1x_syncpt_get() - obtain a syncpoint by ID
+ * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
+ * @host: host1x controller
+ * @id: syncpoint ID
+ */
+struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
+					      unsigned int id)
+{
+	if (id >= host->info->nb_pts)
+		return NULL;
+
+	if (kref_get_unless_zero(&host->syncpt[id].ref))
+		return &host->syncpt[id];
+	else
+		return NULL;
+}
+EXPORT_SYMBOL(host1x_syncpt_get_by_id);
+
+/**
+ * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
+ * 	increase the refcount.
  * @host: host1x controller
  * @id: syncpoint ID
  */
-struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
+struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
+						    unsigned int id)
 {
 	if (id >= host->info->nb_pts)
 		return NULL;
 
-	return host->syncpt + id;
+	return &host->syncpt[id];
+}
+EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
+
+/**
+ * host1x_syncpt_get() - increment syncpoint refcount
+ * @sp: syncpoint
+ */
+struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
+{
+	kref_get(&sp->ref);
+
+	return sp;
 }
 EXPORT_SYMBOL(host1x_syncpt_get);
 
@@ -563,3 +500,31 @@ u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
 	return base->id;
 }
 EXPORT_SYMBOL(host1x_syncpt_base_id);
+
+static void do_nothing(struct kref *ref)
+{
+}
+
+/**
+ * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
+ *   available for allocation
+ *
+ * @client: host1x bus client
+ * @syncpt_id: syncpoint ID to make available
+ *
+ * Makes VBLANK<i> syncpoint available for allocatation if it was
+ * reserved at initialization time. This should be called by the display
+ * driver after it has ensured that any VBLANK increment programming configured
+ * by the boot chain has been disabled.
+ */
+void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
+					      u32 syncpt_id)
+{
+	struct host1x *host = dev_get_drvdata(client->host->parent);
+
+	if (!host->info->reserve_vblank_syncpts)
+		return;
+
+	kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
+}
+EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);