gpu: host1x: Cleanup and refcounting for syncpoints

Add reference counting for allocated syncpoints to allow keeping
them allocated while jobs are referencing them. Additionally,
clean up various places using syncpoint IDs to use host1x_syncpt
pointers instead.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

8 files changed, 76 insertions, 39 deletions

diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c
index e8d3fda91d8a..6e6ca774f68d 100644
--- a/drivers/gpu/host1x/cdma.c
+++ b/drivers/gpu/host1x/cdma.c
@@ -273,15 +273,13 @@ static int host1x_cdma_wait_pushbuffer_space(struct host1x *host1x,
 static void cdma_start_timer_locked(struct host1x_cdma *cdma,
 				    struct host1x_job *job)
 {
-	struct host1x *host = cdma_to_host1x(cdma);
-
 	if (cdma->timeout.client) {
 		/* timer already started */
 		return;
 	}
 
 	cdma->timeout.client = job->client;
-	cdma->timeout.syncpt = host1x_syncpt_get(host, job->syncpt_id);
+	cdma->timeout.syncpt = job->syncpt;
 	cdma->timeout.syncpt_val = job->syncpt_end;
 	cdma->timeout.start_ktime = ktime_get();
 
@@ -312,7 +310,6 @@ static void stop_cdma_timer_locked(struct host1x_cdma *cdma)
 static void update_cdma_locked(struct host1x_cdma *cdma)
 {
 	bool signal = false;
-	struct host1x *host1x = cdma_to_host1x(cdma);
 	struct host1x_job *job, *n;
 
 	/* If CDMA is stopped, queue is cleared and we can return */
@@ -324,8 +321,7 @@ static void update_cdma_locked(struct host1x_cdma *cdma)
 	 * to consume as many sync queue entries as possible without blocking
 	 */
 	list_for_each_entry_safe(job, n, &cdma->sync_queue, list) {
-		struct host1x_syncpt *sp =
-			host1x_syncpt_get(host1x, job->syncpt_id);
+		struct host1x_syncpt *sp = job->syncpt;
 
 		/* Check whether this syncpt has completed, and bail if not */
 		if (!host1x_syncpt_is_expired(sp, job->syncpt_end)) {
@@ -499,8 +495,7 @@ int host1x_cdma_begin(struct host1x_cdma *cdma, struct host1x_job *job)
 		if (!cdma->timeout.initialized) {
 			int err;
 
-			err = host1x_hw_cdma_timeout_init(host1x, cdma,
-							  job->syncpt_id);
+			err = host1x_hw_cdma_timeout_init(host1x, cdma);
 			if (err) {
 				mutex_unlock(&cdma->lock);
 				return err;
diff --git a/drivers/gpu/host1x/dev.h b/drivers/gpu/host1x/dev.h
index f781a9b0f39d..63010ae37a97 100644
--- a/drivers/gpu/host1x/dev.h
+++ b/drivers/gpu/host1x/dev.h
@@ -37,7 +37,7 @@ struct host1x_cdma_ops {
 	void (*start)(struct host1x_cdma *cdma);
 	void (*stop)(struct host1x_cdma *cdma);
 	void (*flush)(struct  host1x_cdma *cdma);
-	int (*timeout_init)(struct host1x_cdma *cdma, unsigned int syncpt);
+	int (*timeout_init)(struct host1x_cdma *cdma);
 	void (*timeout_destroy)(struct host1x_cdma *cdma);
 	void (*freeze)(struct host1x_cdma *cdma);
 	void (*resume)(struct host1x_cdma *cdma, u32 getptr);
@@ -261,10 +261,9 @@ static inline void host1x_hw_cdma_flush(struct host1x *host,
 }
 
 static inline int host1x_hw_cdma_timeout_init(struct host1x *host,
-					      struct host1x_cdma *cdma,
-					      unsigned int syncpt)
+					      struct host1x_cdma *cdma)
 {
-	return host->cdma_op->timeout_init(cdma, syncpt);
+	return host->cdma_op->timeout_init(cdma);
 }
 
 static inline void host1x_hw_cdma_timeout_destroy(struct host1x *host,
diff --git a/drivers/gpu/host1x/hw/cdma_hw.c b/drivers/gpu/host1x/hw/cdma_hw.c
index 2f3bf94cf365..e49cd5b8f735 100644
--- a/drivers/gpu/host1x/hw/cdma_hw.c
+++ b/drivers/gpu/host1x/hw/cdma_hw.c
@@ -295,7 +295,7 @@ static void cdma_timeout_handler(struct work_struct *work)
 /*
  * Init timeout resources
  */
-static int cdma_timeout_init(struct host1x_cdma *cdma, unsigned int syncpt)
+static int cdma_timeout_init(struct host1x_cdma *cdma)
 {
 	INIT_DELAYED_WORK(&cdma->timeout.wq, cdma_timeout_handler);
 	cdma->timeout.initialized = true;
diff --git a/drivers/gpu/host1x/hw/channel_hw.c b/drivers/gpu/host1x/hw/channel_hw.c
index 5eaa29d171c9..d4c28faf27d1 100644
--- a/drivers/gpu/host1x/hw/channel_hw.c
+++ b/drivers/gpu/host1x/hw/channel_hw.c
@@ -86,8 +86,7 @@ static void submit_gathers(struct host1x_job *job)
 
 static inline void synchronize_syncpt_base(struct host1x_job *job)
 {
-	struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
-	struct host1x_syncpt *sp = host->syncpt + job->syncpt_id;
+	struct host1x_syncpt *sp = job->syncpt;
 	unsigned int id;
 	u32 value;
 
@@ -118,7 +117,7 @@ static void host1x_channel_set_streamid(struct host1x_channel *channel)
 static int channel_submit(struct host1x_job *job)
 {
 	struct host1x_channel *ch = job->channel;
-	struct host1x_syncpt *sp;
+	struct host1x_syncpt *sp = job->syncpt;
 	u32 user_syncpt_incrs = job->syncpt_incrs;
 	u32 prev_max = 0;
 	u32 syncval;
@@ -126,10 +125,9 @@ static int channel_submit(struct host1x_job *job)
 	struct host1x_waitlist *completed_waiter = NULL;
 	struct host1x *host = dev_get_drvdata(ch->dev->parent);
 
-	sp = host->syncpt + job->syncpt_id;
 	trace_host1x_channel_submit(dev_name(ch->dev),
 				    job->num_gathers, job->num_relocs,
-				    job->syncpt_id, job->syncpt_incrs);
+				    job->syncpt->id, job->syncpt_incrs);
 
 	/* before error checks, return current max */
 	prev_max = job->syncpt_end = host1x_syncpt_read_max(sp);
@@ -163,7 +161,7 @@ static int channel_submit(struct host1x_job *job)
 		host1x_cdma_push(&ch->cdma,
 				 host1x_opcode_setclass(HOST1X_CLASS_HOST1X,
 					host1x_uclass_wait_syncpt_r(), 1),
-				 host1x_class_host_wait_syncpt(job->syncpt_id,
+				 host1x_class_host_wait_syncpt(job->syncpt->id,
 					host1x_syncpt_read_max(sp)));
 	}
 
diff --git a/drivers/gpu/host1x/hw/debug_hw.c b/drivers/gpu/host1x/hw/debug_hw.c
index f31bcfa1b837..ceb48229d14b 100644
--- a/drivers/gpu/host1x/hw/debug_hw.c
+++ b/drivers/gpu/host1x/hw/debug_hw.c
@@ -204,7 +204,7 @@ static void show_channel_gathers(struct output *o, struct host1x_cdma *cdma)
 		unsigned int i;
 
 		host1x_debug_output(o, "\n%p: JOB, syncpt_id=%d, syncpt_val=%d, first_get=%08x, timeout=%d num_slots=%d, num_handles=%d\n",
-				    job, job->syncpt_id, job->syncpt_end,
+				    job, job->syncpt->id, job->syncpt_end,
 				    job->first_get, job->timeout,
 				    job->num_slots, job->num_unpins);
 
diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index 82d0a60ba3f7..adbdc225de8d 100644
--- a/drivers/gpu/host1x/job.c
+++ b/drivers/gpu/host1x/job.c
@@ -79,6 +79,9 @@ static void job_free(struct kref *ref)
 {
 	struct host1x_job *job = container_of(ref, struct host1x_job, ref);
 
+	if (job->syncpt)
+		host1x_syncpt_put(job->syncpt);
+
 	kfree(job);
 }
 
@@ -674,7 +677,7 @@ EXPORT_SYMBOL(host1x_job_unpin);
  */
 void host1x_job_dump(struct device *dev, struct host1x_job *job)
 {
-	dev_dbg(dev, "    SYNCPT_ID   %d\n", job->syncpt_id);
+	dev_dbg(dev, "    SYNCPT_ID   %d\n", job->syncpt->id);
 	dev_dbg(dev, "    SYNCPT_VAL  %d\n", job->syncpt_end);
 	dev_dbg(dev, "    FIRST_GET   0x%x\n", job->first_get);
 	dev_dbg(dev, "    TIMEOUT     %d\n", job->timeout);
diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c
index 8da4bbce8b9d..7bb5de8c3d63 100644
--- a/drivers/gpu/host1x/syncpt.c
+++ b/drivers/gpu/host1x/syncpt.c
@@ -90,6 +90,8 @@ struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
 	else
 		sp->client_managed = false;
 
+	kref_init(&sp->ref);
+
 	mutex_unlock(&host->syncpt_mutex);
 	return sp;
 
@@ -383,7 +385,7 @@ 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)
@@ -394,20 +396,9 @@ struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 }
 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);
 
 	mutex_lock(&sp->host->syncpt_mutex);
 
@@ -419,7 +410,23 @@ void host1x_syncpt_free(struct host1x_syncpt *sp)
 
 	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(&sp->ref, syncpt_release);
+}
+EXPORT_SYMBOL(host1x_syncpt_put);
 
 void host1x_syncpt_deinit(struct host1x *host)
 {
@@ -486,16 +493,48 @@ 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);
 
diff --git a/drivers/gpu/host1x/syncpt.h b/drivers/gpu/host1x/syncpt.h
index 3aa6b25b1b9c..a6766f8d55ee 100644
--- a/drivers/gpu/host1x/syncpt.h
+++ b/drivers/gpu/host1x/syncpt.h
@@ -11,6 +11,7 @@
 #include <linux/atomic.h>
 #include <linux/host1x.h>
 #include <linux/kernel.h>
+#include <linux/kref.h>
 #include <linux/sched.h>
 
 #include "intr.h"
@@ -26,6 +27,8 @@ struct host1x_syncpt_base {
 };
 
 struct host1x_syncpt {
+	struct kref ref;
+
 	unsigned int id;
 	atomic_t min_val;
 	atomic_t max_val;