[PATCH v3 06/20] gpu: host1x: Cleanup and refcounting for syncpoints

Mikko Perttunen mperttunen at nvidia.com
Wed Oct 7 17:12:24 UTC 2020


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 at nvidia.com>
---
 drivers/gpu/drm/tegra/dc.c         |  4 +-
 drivers/gpu/drm/tegra/drm.c        | 17 ++++---
 drivers/gpu/drm/tegra/gr2d.c       |  4 +-
 drivers/gpu/drm/tegra/gr3d.c       |  4 +-
 drivers/gpu/drm/tegra/vic.c        |  4 +-
 drivers/gpu/host1x/cdma.c          | 11 ++---
 drivers/gpu/host1x/dev.h           |  7 ++-
 drivers/gpu/host1x/hw/cdma_hw.c    |  2 +-
 drivers/gpu/host1x/hw/channel_hw.c | 10 ++--
 drivers/gpu/host1x/hw/debug_hw.c   |  2 +-
 drivers/gpu/host1x/job.c           |  5 +-
 drivers/gpu/host1x/syncpt.c        | 75 +++++++++++++++++++++++-------
 drivers/gpu/host1x/syncpt.h        |  3 ++
 include/linux/host1x.h             |  8 ++--
 14 files changed, 99 insertions(+), 57 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 9a0b3240bc58..efb41c10dad4 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -2127,7 +2127,7 @@ static int tegra_dc_init(struct host1x_client *client)
 		drm_plane_cleanup(primary);
 
 	host1x_client_iommu_detach(client);
-	host1x_syncpt_free(dc->syncpt);
+	host1x_syncpt_put(dc->syncpt);
 
 	return err;
 }
@@ -2152,7 +2152,7 @@ static int tegra_dc_exit(struct host1x_client *client)
 	}
 
 	host1x_client_iommu_detach(client);
-	host1x_syncpt_free(dc->syncpt);
+	host1x_syncpt_put(dc->syncpt);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index ba9d1c3e7cac..ceea9db341f0 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -171,7 +171,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 	struct drm_tegra_syncpt syncpt;
 	struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
 	struct drm_gem_object **refs;
-	struct host1x_syncpt *sp;
+	struct host1x_syncpt *sp = NULL;
 	struct host1x_job *job;
 	unsigned int num_refs;
 	int err;
@@ -298,8 +298,8 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 		goto fail;
 	}
 
-	/* check whether syncpoint ID is valid */
-	sp = host1x_syncpt_get(host1x, syncpt.id);
+	/* Syncpoint ref will be dropped on job release. */
+	sp = host1x_syncpt_get_by_id(host1x, syncpt.id);
 	if (!sp) {
 		err = -ENOENT;
 		goto fail;
@@ -308,7 +308,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 	job->is_addr_reg = context->client->ops->is_addr_reg;
 	job->is_valid_class = context->client->ops->is_valid_class;
 	job->syncpt_incrs = syncpt.incrs;
-	job->syncpt_id = syncpt.id;
+	job->syncpt = sp;
 	job->timeout = 10000;
 
 	if (args->timeout && args->timeout < 10000)
@@ -327,6 +327,9 @@ int tegra_drm_submit(struct tegra_drm_context *context,
 	args->fence = job->syncpt_end;
 
 fail:
+	if (sp)
+		host1x_syncpt_put(sp);
+
 	while (num_refs--)
 		drm_gem_object_put(refs[num_refs]);
 
@@ -380,7 +383,7 @@ static int tegra_syncpt_read(struct drm_device *drm, void *data,
 	struct drm_tegra_syncpt_read *args = data;
 	struct host1x_syncpt *sp;
 
-	sp = host1x_syncpt_get(host, args->id);
+	sp = host1x_syncpt_get_by_id_noref(host, args->id);
 	if (!sp)
 		return -EINVAL;
 
@@ -395,7 +398,7 @@ static int tegra_syncpt_incr(struct drm_device *drm, void *data,
 	struct drm_tegra_syncpt_incr *args = data;
 	struct host1x_syncpt *sp;
 
-	sp = host1x_syncpt_get(host1x, args->id);
+	sp = host1x_syncpt_get_by_id_noref(host1x, args->id);
 	if (!sp)
 		return -EINVAL;
 
@@ -409,7 +412,7 @@ static int tegra_syncpt_wait(struct drm_device *drm, void *data,
 	struct drm_tegra_syncpt_wait *args = data;
 	struct host1x_syncpt *sp;
 
-	sp = host1x_syncpt_get(host1x, args->id);
+	sp = host1x_syncpt_get_by_id_noref(host1x, args->id);
 	if (!sp)
 		return -EINVAL;
 
diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index 1a0d3ba6e525..d857a99b21a7 100644
--- a/drivers/gpu/drm/tegra/gr2d.c
+++ b/drivers/gpu/drm/tegra/gr2d.c
@@ -67,7 +67,7 @@ static int gr2d_init(struct host1x_client *client)
 detach:
 	host1x_client_iommu_detach(client);
 free:
-	host1x_syncpt_free(client->syncpts[0]);
+	host1x_syncpt_put(client->syncpts[0]);
 put:
 	host1x_channel_put(gr2d->channel);
 	return err;
@@ -86,7 +86,7 @@ static int gr2d_exit(struct host1x_client *client)
 		return err;
 
 	host1x_client_iommu_detach(client);
-	host1x_syncpt_free(client->syncpts[0]);
+	host1x_syncpt_put(client->syncpts[0]);
 	host1x_channel_put(gr2d->channel);
 
 	return 0;
diff --git a/drivers/gpu/drm/tegra/gr3d.c b/drivers/gpu/drm/tegra/gr3d.c
index b0b8154e8104..24442ade0da3 100644
--- a/drivers/gpu/drm/tegra/gr3d.c
+++ b/drivers/gpu/drm/tegra/gr3d.c
@@ -76,7 +76,7 @@ static int gr3d_init(struct host1x_client *client)
 detach:
 	host1x_client_iommu_detach(client);
 free:
-	host1x_syncpt_free(client->syncpts[0]);
+	host1x_syncpt_put(client->syncpts[0]);
 put:
 	host1x_channel_put(gr3d->channel);
 	return err;
@@ -94,7 +94,7 @@ static int gr3d_exit(struct host1x_client *client)
 		return err;
 
 	host1x_client_iommu_detach(client);
-	host1x_syncpt_free(client->syncpts[0]);
+	host1x_syncpt_put(client->syncpts[0]);
 	host1x_channel_put(gr3d->channel);
 
 	return 0;
diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
index ade56b860cf9..cb476da59adc 100644
--- a/drivers/gpu/drm/tegra/vic.c
+++ b/drivers/gpu/drm/tegra/vic.c
@@ -197,7 +197,7 @@ static int vic_init(struct host1x_client *client)
 	return 0;
 
 free_syncpt:
-	host1x_syncpt_free(client->syncpts[0]);
+	host1x_syncpt_put(client->syncpts[0]);
 free_channel:
 	host1x_channel_put(vic->channel);
 detach:
@@ -221,7 +221,7 @@ static int vic_exit(struct host1x_client *client)
 	if (err < 0)
 		return err;
 
-	host1x_syncpt_free(client->syncpts[0]);
+	host1x_syncpt_put(client->syncpts[0]);
 	host1x_channel_put(vic->channel);
 	host1x_client_iommu_detach(client);
 
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 89b6c14b7392..d8345d3bf0b3 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);
 }
 
@@ -680,7 +683,7 @@ 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 9ca0d852e32f..c7b910e413d8 100644
--- a/drivers/gpu/host1x/syncpt.c
+++ b/drivers/gpu/host1x/syncpt.c
@@ -75,6 +75,8 @@ 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;
 
@@ -368,7 +370,7 @@ 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)
@@ -379,20 +381,9 @@ 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);
 
@@ -404,7 +395,23 @@ 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)
 {
@@ -471,16 +478,48 @@ 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;
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index 099eff8a06d2..c222cf61b70b 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -142,7 +142,9 @@ struct host1x_syncpt_base;
 struct host1x_syncpt;
 struct host1x;
 
-struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, u32 id);
+struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host, u32 id);
+struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host, u32 id);
+struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp);
 u32 host1x_syncpt_id(struct host1x_syncpt *sp);
 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp);
 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp);
@@ -153,7 +155,7 @@ int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 		       u32 *value);
 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 					    unsigned long flags);
-void host1x_syncpt_free(struct host1x_syncpt *sp);
+void host1x_syncpt_put(struct host1x_syncpt *sp);
 struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
 					  unsigned long flags,
 					  const char *name);
@@ -221,7 +223,7 @@ struct host1x_job {
 	dma_addr_t *reloc_addr_phys;
 
 	/* Sync point id, number of increments and end related to the submit */
-	u32 syncpt_id;
+	struct host1x_syncpt *syncpt;
 	u32 syncpt_incrs;
 	u32 syncpt_end;
 
-- 
2.28.0



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