diff mbox series

[v6,01/14] gpu: host1x: Add DMA fence implementation

Message ID 20210530122156.3292479-2-mperttunen@nvidia.com (mailing list archive)
State New, archived
Headers show
Series TegraDRM UAPI | expand

Commit Message

Mikko Perttunen May 30, 2021, 12:21 p.m. UTC
Add an implementation of dma_fences based on syncpoints. Syncpoint
interrupts are used to signal fences. Additionally, after
software signaling has been enabled, a 30 second timeout is started.
If the syncpoint threshold is not reached within this period,
the fence is signalled with an -ETIMEDOUT error code. This is to
allow fences that would never reach their syncpoint threshold to
be cleaned up. The timeout can potentially be removed in the future
after job tracking code has been refactored.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
v6:
* Removed userspace interface.
* Add host1x_ prefixes in various places.
v5:
* Update for change in put_ref prototype.
v4:
* Fix _signal prototype and include it to avoid warning
* Remove use of unused local in error path
v3:
* Move declaration of host1x_fence_extract to public header
---
 drivers/gpu/host1x/Makefile |   1 +
 drivers/gpu/host1x/fence.c  | 211 ++++++++++++++++++++++++++++++++++++
 drivers/gpu/host1x/fence.h  |  13 +++
 drivers/gpu/host1x/intr.c   |   9 ++
 drivers/gpu/host1x/intr.h   |   2 +
 include/linux/host1x.h      |   3 +
 6 files changed, 239 insertions(+)
 create mode 100644 drivers/gpu/host1x/fence.c
 create mode 100644 drivers/gpu/host1x/fence.h

Comments

kernel test robot May 30, 2021, 1:45 p.m. UTC | #1
Hi Mikko,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tegra-drm/drm/tegra/for-next]
[also build test WARNING on v5.13-rc3 next-20210528]
[cannot apply to tegra/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Mikko-Perttunen/TegraDRM-UAPI/20210530-205239
base:   git://anongit.freedesktop.org/tegra/linux.git drm/tegra/for-next
config: arm-randconfig-r015-20210530 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project bc6799f2f79f0ae87e9f1ebf9d25ba799fbd25a9)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/0day-ci/linux/commit/5de49ce9211cbf0fbbfeb200e72ce934f4574d4b
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Mikko-Perttunen/TegraDRM-UAPI/20210530-205239
        git checkout 5de49ce9211cbf0fbbfeb200e72ce934f4574d4b
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/gpu/host1x/fence.c:170:5: warning: no previous prototype for function 'host1x_fence_create_fd' [-Wmissing-prototypes]
   int host1x_fence_create_fd(struct host1x_syncpt *sp, u32 threshold)
       ^
   drivers/gpu/host1x/fence.c:170:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int host1x_fence_create_fd(struct host1x_syncpt *sp, u32 threshold)
   ^
   static 
   1 warning generated.


vim +/host1x_fence_create_fd +170 drivers/gpu/host1x/fence.c

   169	
 > 170	int host1x_fence_create_fd(struct host1x_syncpt *sp, u32 threshold)
   171	{
   172		struct sync_file *file;
   173		struct dma_fence *f;
   174		int fd;
   175	
   176		f = host1x_fence_create(sp, threshold);
   177		if (IS_ERR(f))
   178			return PTR_ERR(f);
   179	
   180		fd = get_unused_fd_flags(O_CLOEXEC);
   181		if (fd < 0) {
   182			dma_fence_put(f);
   183			return fd;
   184		}
   185	
   186		file = sync_file_create(f);
   187		dma_fence_put(f);
   188		if (!file)
   189			return -ENOMEM;
   190	
   191		fd_install(fd, file->file);
   192	
   193		return fd;
   194	}
   195	EXPORT_SYMBOL(host1x_fence_create_fd);
   196	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/drivers/gpu/host1x/Makefile b/drivers/gpu/host1x/Makefile
index 096017b8789d..d2b6f7de0498 100644
--- a/drivers/gpu/host1x/Makefile
+++ b/drivers/gpu/host1x/Makefile
@@ -9,6 +9,7 @@  host1x-y = \
 	job.o \
 	debug.o \
 	mipi.o \
+	fence.o \
 	hw/host1x01.o \
 	hw/host1x02.o \
 	hw/host1x04.o \
diff --git a/drivers/gpu/host1x/fence.c b/drivers/gpu/host1x/fence.c
new file mode 100644
index 000000000000..fde59cd8487b
--- /dev/null
+++ b/drivers/gpu/host1x/fence.c
@@ -0,0 +1,211 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Syncpoint dma_fence implementation
+ *
+ * Copyright (c) 2020, NVIDIA Corporation.
+ */
+
+#include <linux/dma-fence.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/sync_file.h>
+
+#include "fence.h"
+#include "intr.h"
+#include "syncpt.h"
+
+DEFINE_SPINLOCK(lock);
+
+struct host1x_syncpt_fence {
+	struct dma_fence base;
+
+	atomic_t signaling;
+
+	struct host1x_syncpt *sp;
+	u32 threshold;
+
+	struct host1x_waitlist *waiter;
+	void *waiter_ref;
+
+	struct delayed_work timeout_work;
+};
+
+static const char *host1x_syncpt_fence_get_driver_name(struct dma_fence *f)
+{
+	return "host1x";
+}
+
+static const char *host1x_syncpt_fence_get_timeline_name(struct dma_fence *f)
+{
+	return "syncpoint";
+}
+
+static struct host1x_syncpt_fence *to_host1x_fence(struct dma_fence *f)
+{
+	return container_of(f, struct host1x_syncpt_fence, base);
+}
+
+static bool host1x_syncpt_fence_enable_signaling(struct dma_fence *f)
+{
+	struct host1x_syncpt_fence *sf = to_host1x_fence(f);
+	int err;
+
+	if (host1x_syncpt_is_expired(sf->sp, sf->threshold))
+		return false;
+
+	dma_fence_get(f);
+
+	/*
+	 * The dma_fence framework requires the fence driver to keep a
+	 * reference to any fences for which 'enable_signaling' has been
+	 * called (and that have not been signalled).
+	 * 
+	 * We provide a userspace API to create arbitrary syncpoint fences,
+	 * so we cannot normally guarantee that all fences get signalled.
+	 * As such, setup a timeout, so that long-lasting fences will get
+	 * reaped eventually.
+	 */
+	schedule_delayed_work(&sf->timeout_work, msecs_to_jiffies(30000));
+
+	err = host1x_intr_add_action(sf->sp->host, sf->sp, sf->threshold,
+				     HOST1X_INTR_ACTION_SIGNAL_FENCE, f,
+				     sf->waiter, &sf->waiter_ref);
+	if (err) {
+		cancel_delayed_work_sync(&sf->timeout_work);
+		dma_fence_put(f);
+		return false;
+	}
+
+	/* intr framework takes ownership of waiter */
+	sf->waiter = NULL;
+
+	/*
+	 * The fence may get signalled at any time after the above call,
+	 * so we need to initialize all state used by signalling
+	 * before it.
+	 */
+
+	return true;
+}
+
+static void host1x_syncpt_fence_release(struct dma_fence *f)
+{
+	struct host1x_syncpt_fence *sf = to_host1x_fence(f);
+
+	if (sf->waiter)
+		kfree(sf->waiter);
+
+	dma_fence_free(f);
+}
+
+const struct dma_fence_ops host1x_syncpt_fence_ops = {
+	.get_driver_name = host1x_syncpt_fence_get_driver_name,
+	.get_timeline_name = host1x_syncpt_fence_get_timeline_name,
+	.enable_signaling = host1x_syncpt_fence_enable_signaling,
+	.release = host1x_syncpt_fence_release,
+};
+
+void host1x_fence_signal(struct host1x_syncpt_fence *f)
+{
+	if (atomic_xchg(&f->signaling, 1))
+		return;
+
+	/*
+	 * Cancel pending timeout work - if it races, it will
+	 * not get 'f->signaling' and return.
+	 */
+	cancel_delayed_work_sync(&f->timeout_work);
+
+	host1x_intr_put_ref(f->sp->host, f->sp->id, f->waiter_ref, false);
+
+	dma_fence_signal(&f->base);
+	dma_fence_put(&f->base);
+}
+
+static void do_fence_timeout(struct work_struct *work)
+{
+	struct delayed_work *dwork = (struct delayed_work *)work;
+	struct host1x_syncpt_fence *f =
+		container_of(dwork, struct host1x_syncpt_fence, timeout_work);
+
+	if (atomic_xchg(&f->signaling, 1))
+		return;
+
+	/*
+	 * Cancel pending timeout work - if it races, it will
+	 * not get 'f->signaling' and return.
+	 */
+	host1x_intr_put_ref(f->sp->host, f->sp->id, f->waiter_ref, true);
+
+	dma_fence_set_error(&f->base, -ETIMEDOUT);
+	dma_fence_signal(&f->base);
+	dma_fence_put(&f->base);
+}
+
+struct dma_fence *host1x_fence_create(struct host1x_syncpt *sp, u32 threshold)
+{
+	struct host1x_syncpt_fence *fence;
+
+	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+	if (!fence)
+		return ERR_PTR(-ENOMEM);
+
+	fence->waiter = kzalloc(sizeof(*fence->waiter), GFP_KERNEL);
+	if (!fence->waiter)
+		return ERR_PTR(-ENOMEM);
+
+	fence->sp = sp;
+	fence->threshold = threshold;
+
+	dma_fence_init(&fence->base, &host1x_syncpt_fence_ops, &lock,
+		       dma_fence_context_alloc(1), 0);
+
+	INIT_DELAYED_WORK(&fence->timeout_work, do_fence_timeout);
+
+	return &fence->base;
+}
+EXPORT_SYMBOL(host1x_fence_create);
+
+int host1x_fence_create_fd(struct host1x_syncpt *sp, u32 threshold)
+{
+	struct sync_file *file;
+	struct dma_fence *f;
+	int fd;
+
+	f = host1x_fence_create(sp, threshold);
+	if (IS_ERR(f))
+		return PTR_ERR(f);
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0) {
+		dma_fence_put(f);
+		return fd;
+	}
+
+	file = sync_file_create(f);
+	dma_fence_put(f);
+	if (!file)
+		return -ENOMEM;
+
+	fd_install(fd, file->file);
+
+	return fd;
+}
+EXPORT_SYMBOL(host1x_fence_create_fd);
+
+int host1x_fence_extract(struct dma_fence *fence, u32 *id, u32 *threshold)
+{
+	struct host1x_syncpt_fence *f;
+
+	if (fence->ops != &host1x_syncpt_fence_ops)
+		return -EINVAL;
+
+	f = container_of(fence, struct host1x_syncpt_fence, base);
+
+	*id = f->sp->id;
+	*threshold = f->threshold;
+
+	return 0;
+}
+EXPORT_SYMBOL(host1x_fence_extract);
diff --git a/drivers/gpu/host1x/fence.h b/drivers/gpu/host1x/fence.h
new file mode 100644
index 000000000000..70c91de82f14
--- /dev/null
+++ b/drivers/gpu/host1x/fence.h
@@ -0,0 +1,13 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2020, NVIDIA Corporation.
+ */
+
+#ifndef HOST1X_FENCE_H
+#define HOST1X_FENCE_H
+
+struct host1x_syncpt_fence;
+
+void host1x_fence_signal(struct host1x_syncpt_fence *fence);
+
+#endif
diff --git a/drivers/gpu/host1x/intr.c b/drivers/gpu/host1x/intr.c
index 6d1f3c0fdbe7..45b6be927ec4 100644
--- a/drivers/gpu/host1x/intr.c
+++ b/drivers/gpu/host1x/intr.c
@@ -13,6 +13,7 @@ 
 #include <trace/events/host1x.h>
 #include "channel.h"
 #include "dev.h"
+#include "fence.h"
 #include "intr.h"
 
 /* Wait list management */
@@ -121,12 +122,20 @@  static void action_wakeup_interruptible(struct host1x_waitlist *waiter)
 	wake_up_interruptible(wq);
 }
 
+static void action_signal_fence(struct host1x_waitlist *waiter)
+{
+	struct host1x_syncpt_fence *f = waiter->data;
+
+	host1x_fence_signal(f);
+}
+
 typedef void (*action_handler)(struct host1x_waitlist *waiter);
 
 static const action_handler action_handlers[HOST1X_INTR_ACTION_COUNT] = {
 	action_submit_complete,
 	action_wakeup,
 	action_wakeup_interruptible,
+	action_signal_fence,
 };
 
 static void run_handlers(struct list_head completed[HOST1X_INTR_ACTION_COUNT])
diff --git a/drivers/gpu/host1x/intr.h b/drivers/gpu/host1x/intr.h
index 6ea55e615e3a..e4c346099273 100644
--- a/drivers/gpu/host1x/intr.h
+++ b/drivers/gpu/host1x/intr.h
@@ -33,6 +33,8 @@  enum host1x_intr_action {
 	 */
 	HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
 
+	HOST1X_INTR_ACTION_SIGNAL_FENCE,
+
 	HOST1X_INTR_ACTION_COUNT
 };
 
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index e0a41c2b4c7a..f2ea24fe0b0d 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -166,6 +166,9 @@  u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base);
 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
 					      u32 syncpt_id);
 
+struct dma_fence *host1x_fence_create(struct host1x_syncpt *sp, u32 threshold);
+int host1x_fence_extract(struct dma_fence *fence, u32 *id, u32 *threshold);
+
 /*
  * host1x channel
  */