[PATCH v6 02/10] gpu: host1x: Allow syncpoints without associated client

[Mikko Perttunen]

Syncpoints don't need to be associated with any client,
so remove the property, and expose host1x_syncpt_alloc.
This will allow allocating syncpoints without prior knowledge
of the engine that it will be used with.

Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
---
v6:
* Add kerneldoc
* Return error if a NULL name was specified
v3:
* Clean up host1x_syncpt_alloc signature to allow specifying
  a name for the syncpoint.
* Export the function.
---
 drivers/gpu/host1x/syncpt.c | 37 +++++++++++++++++++++++++------------
 drivers/gpu/host1x/syncpt.h |  1 -
 include/linux/host1x.h      |  3 +++
 3 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c
index fce7892d5137..9a113016d482 100644
--- a/drivers/gpu/host1x/syncpt.c
+++ b/drivers/gpu/host1x/syncpt.c
@@ -42,13 +42,28 @@ 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);
 
@@ -64,13 +79,11 @@ 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;
@@ -87,6 +100,7 @@ static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
 	mutex_unlock(&host->syncpt_mutex);
 	return NULL;
 }
+EXPORT_SYMBOL(host1x_syncpt_alloc);
 
 /**
  * host1x_syncpt_id() - retrieve syncpoint ID
@@ -401,7 +415,7 @@ int host1x_syncpt_init(struct host1x *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;
 
@@ -423,7 +437,7 @@ struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 {
 	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);
 
@@ -447,7 +461,6 @@ void host1x_syncpt_free(struct host1x_syncpt *sp)
 	host1x_syncpt_base_free(sp->base);
 	kfree(sp->name);
 	sp->base = NULL;
-	sp->client = NULL;
 	sp->name = NULL;
 	sp->client_managed = false;
 
diff --git a/drivers/gpu/host1x/syncpt.h b/drivers/gpu/host1x/syncpt.h
index 8e1d04dacaa0..3aa6b25b1b9c 100644
--- a/drivers/gpu/host1x/syncpt.h
+++ b/drivers/gpu/host1x/syncpt.h
@@ -33,7 +33,6 @@ struct host1x_syncpt {
 	const char *name;
 	bool client_managed;
 	struct host1x *host;
-	struct host1x_client *client;
 	struct host1x_syncpt_base *base;
 
 	/* interrupt data */
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index 9eb77c87a83b..7137ce0e35d4 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -154,6 +154,9 @@ int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 					    unsigned long flags);
 void host1x_syncpt_free(struct host1x_syncpt *sp);
+struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
+					  unsigned long flags,
+					  const char *name);
 
 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp);
 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base);
-- 
2.30.1