2023-02-28 22:58:43

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 00/16] dma-fence: Deadline awareness

From: Rob Clark <[email protected]>

This series adds a deadline hint to fences, so realtime deadlines
such as vblank can be communicated to the fence signaller for power/
frequency management decisions.

This is partially inspired by a trick i915 does, but implemented
via dma-fence for a couple of reasons:

1) To continue to be able to use the atomic helpers
2) To support cases where display and gpu are different drivers

This iteration adds a dma-fence ioctl to set a deadline (both to
support igt-tests, and compositors which delay decisions about which
client buffer to display), and a sw_sync ioctl to read back the
deadline. IGT tests utilizing these can be found at:

https://gitlab.freedesktop.org/robclark/igt-gpu-tools/-/commits/fence-deadline


v1: https://patchwork.freedesktop.org/series/93035/
v2: Move filtering out of later deadlines to fence implementation
to avoid increasing the size of dma_fence
v3: Add support in fence-array and fence-chain; Add some uabi to
support igt tests and userspace compositors.
v4: Rebase, address various comments, and add syncobj deadline
support, and sync_file EPOLLPRI based on experience with perf/
freq issues with clvk compute workloads on i915 (anv)
v5: Clarify that this is a hint as opposed to a more hard deadline
guarantee, switch to using u64 ns values in UABI (still absolute
CLOCK_MONOTONIC values), drop syncobj related cap and driver
feature flag in favor of allowing count_handles==0 for probing
kernel support.
v6: Re-work vblank helper to calculate time of _start_ of vblank,
and work correctly if the last vblank event was more than a
frame ago. Add (mostly unrelated) drm/msm patch which also
uses the vblank helper. Use dma_fence_chain_contained(). More
verbose syncobj UABI comments. Drop DMA_FENCE_FLAG_HAS_DEADLINE_BIT.
v7: Fix kbuild complaints about vblank helper. Add more docs.
v8: Add patch to surface sync_file UAPI, and more docs updates.

Rob Clark (16):
dma-buf/dma-fence: Add deadline awareness
dma-buf/fence-array: Add fence deadline support
dma-buf/fence-chain: Add fence deadline support
dma-buf/dma-resv: Add a way to set fence deadline
dma-buf/sync_file: Surface sync-file uABI
dma-buf/sync_file: Add SET_DEADLINE ioctl
dma-buf/sync_file: Support (E)POLLPRI
dma-buf/sw_sync: Add fence deadline support
drm/scheduler: Add fence deadline support
drm/syncobj: Add deadline support for syncobj waits
drm/vblank: Add helper to get next vblank time
drm/atomic-helper: Set fence deadline for vblank
drm/msm: Add deadline based boost support
drm/msm: Add wait-boost support
drm/msm/atomic: Switch to vblank_start helper
drm/i915: Add deadline based boost support

Documentation/driver-api/dma-buf.rst | 16 ++++-
drivers/dma-buf/dma-fence-array.c | 11 ++++
drivers/dma-buf/dma-fence-chain.c | 12 ++++
drivers/dma-buf/dma-fence.c | 60 ++++++++++++++++++
drivers/dma-buf/dma-resv.c | 22 +++++++
drivers/dma-buf/sw_sync.c | 81 +++++++++++++++++++++++++
drivers/dma-buf/sync_debug.h | 2 +
drivers/dma-buf/sync_file.c | 27 +++++++++
drivers/gpu/drm/drm_atomic_helper.c | 36 +++++++++++
drivers/gpu/drm/drm_syncobj.c | 64 +++++++++++++++----
drivers/gpu/drm/drm_vblank.c | 53 +++++++++++++---
drivers/gpu/drm/i915/i915_request.c | 20 ++++++
drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 15 -----
drivers/gpu/drm/msm/msm_atomic.c | 8 ++-
drivers/gpu/drm/msm/msm_drv.c | 12 ++--
drivers/gpu/drm/msm/msm_fence.c | 74 ++++++++++++++++++++++
drivers/gpu/drm/msm/msm_fence.h | 20 ++++++
drivers/gpu/drm/msm/msm_gem.c | 5 ++
drivers/gpu/drm/msm/msm_kms.h | 8 ---
drivers/gpu/drm/scheduler/sched_fence.c | 46 ++++++++++++++
drivers/gpu/drm/scheduler/sched_main.c | 2 +-
include/drm/drm_vblank.h | 1 +
include/drm/gpu_scheduler.h | 17 ++++++
include/linux/dma-fence.h | 22 +++++++
include/linux/dma-resv.h | 2 +
include/uapi/drm/drm.h | 17 ++++++
include/uapi/drm/msm_drm.h | 14 ++++-
include/uapi/linux/sync_file.h | 57 ++++++++++-------
28 files changed, 646 insertions(+), 78 deletions(-)

--
2.39.1



2023-02-28 22:58:46

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 01/16] dma-buf/dma-fence: Add deadline awareness

From: Rob Clark <[email protected]>

Add a way to hint to the fence signaler of an upcoming deadline, such as
vblank, which the fence waiter would prefer not to miss. This is to aid
the fence signaler in making power management decisions, like boosting
frequency as the deadline approaches and awareness of missing deadlines
so that can be factored in to the frequency scaling.

v2: Drop dma_fence::deadline and related logic to filter duplicate
deadlines, to avoid increasing dma_fence size. The fence-context
implementation will need similar logic to track deadlines of all
the fences on the same timeline. [ckoenig]
v3: Clarify locking wrt. set_deadline callback
v4: Clarify in docs comment that this is a hint
v5: Drop DMA_FENCE_FLAG_HAS_DEADLINE_BIT.
v6: More docs
v7: Fix typo, clarify past deadlines

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Christian König <[email protected]>
Acked-by: Pekka Paalanen <[email protected]>
---
Documentation/driver-api/dma-buf.rst | 6 +++
drivers/dma-buf/dma-fence.c | 59 ++++++++++++++++++++++++++++
include/linux/dma-fence.h | 22 +++++++++++
3 files changed, 87 insertions(+)

diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
index 622b8156d212..183e480d8cea 100644
--- a/Documentation/driver-api/dma-buf.rst
+++ b/Documentation/driver-api/dma-buf.rst
@@ -164,6 +164,12 @@ DMA Fence Signalling Annotations
.. kernel-doc:: drivers/dma-buf/dma-fence.c
:doc: fence signalling annotation

+DMA Fence Deadline Hints
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/dma-buf/dma-fence.c
+ :doc: deadline hints
+
DMA Fences Functions Reference
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 0de0482cd36e..f177c56269bb 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -912,6 +912,65 @@ dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count,
}
EXPORT_SYMBOL(dma_fence_wait_any_timeout);

+/**
+ * DOC: deadline hints
+ *
+ * In an ideal world, it would be possible to pipeline a workload sufficiently
+ * that a utilization based device frequency governor could arrive at a minimum
+ * frequency that meets the requirements of the use-case, in order to minimize
+ * power consumption. But in the real world there are many workloads which
+ * defy this ideal. For example, but not limited to:
+ *
+ * * Workloads that ping-pong between device and CPU, with alternating periods
+ * of CPU waiting for device, and device waiting on CPU. This can result in
+ * devfreq and cpufreq seeing idle time in their respective domains and in
+ * result reduce frequency.
+ *
+ * * Workloads that interact with a periodic time based deadline, such as double
+ * buffered GPU rendering vs vblank sync'd page flipping. In this scenario,
+ * missing a vblank deadline results in an *increase* in idle time on the GPU
+ * (since it has to wait an additional vblank period), sending a signal to
+ * the GPU's devfreq to reduce frequency, when in fact the opposite is what is
+ * needed.
+ *
+ * To this end, deadline hint(s) can be set on a &dma_fence via &dma_fence_set_deadline.
+ * The deadline hint provides a way for the waiting driver, or userspace, to
+ * convey an appropriate sense of urgency to the signaling driver.
+ *
+ * A deadline hint is given in absolute ktime (CLOCK_MONOTONIC for userspace
+ * facing APIs). The time could either be some point in the future (such as
+ * the vblank based deadline for page-flipping, or the start of a compositor's
+ * composition cycle), or the current time to indicate an immediate deadline
+ * hint (Ie. forward progress cannot be made until this fence is signaled).
+ *
+ * Multiple deadlines may be set on a given fence, even in parallel. See the
+ * documentation for &dma_fence_ops.set_deadline.
+ *
+ * The deadline hint is just that, a hint. The driver that created the fence
+ * may react by increasing frequency, making different scheduling choices, etc.
+ * Or doing nothing at all.
+ */
+
+/**
+ * dma_fence_set_deadline - set desired fence-wait deadline hint
+ * @fence: the fence that is to be waited on
+ * @deadline: the time by which the waiter hopes for the fence to be
+ * signaled
+ *
+ * Give the fence signaler a hint about an upcoming deadline, such as
+ * vblank, by which point the waiter would prefer the fence to be
+ * signaled by. This is intended to give feedback to the fence signaler
+ * to aid in power management decisions, such as boosting GPU frequency
+ * if a periodic vblank deadline is approaching but the fence is not
+ * yet signaled..
+ */
+void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline)
+{
+ if (fence->ops->set_deadline && !dma_fence_is_signaled(fence))
+ fence->ops->set_deadline(fence, deadline);
+}
+EXPORT_SYMBOL(dma_fence_set_deadline);
+
/**
* dma_fence_describe - Dump fence describtion into seq_file
* @fence: the 6fence to describe
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
index 775cdc0b4f24..d54b595a0fe0 100644
--- a/include/linux/dma-fence.h
+++ b/include/linux/dma-fence.h
@@ -257,6 +257,26 @@ struct dma_fence_ops {
*/
void (*timeline_value_str)(struct dma_fence *fence,
char *str, int size);
+
+ /**
+ * @set_deadline:
+ *
+ * Callback to allow a fence waiter to inform the fence signaler of
+ * an upcoming deadline, such as vblank, by which point the waiter
+ * would prefer the fence to be signaled by. This is intended to
+ * give feedback to the fence signaler to aid in power management
+ * decisions, such as boosting GPU frequency.
+ *
+ * This is called without &dma_fence.lock held, it can be called
+ * multiple times and from any context. Locking is up to the callee
+ * if it has some state to manage. If multiple deadlines are set,
+ * the expectation is to track the soonest one. If the deadline is
+ * before the current time, it should be interpreted as an immediate
+ * deadline.
+ *
+ * This callback is optional.
+ */
+ void (*set_deadline)(struct dma_fence *fence, ktime_t deadline);
};

void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops,
@@ -583,6 +603,8 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr)
return ret < 0 ? ret : 0;
}

+void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline);
+
struct dma_fence *dma_fence_get_stub(void);
struct dma_fence *dma_fence_allocate_private_stub(void);
u64 dma_fence_context_alloc(unsigned num);
--
2.39.1


2023-02-28 22:58:55

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 02/16] dma-buf/fence-array: Add fence deadline support

From: Rob Clark <[email protected]>

Propagate the deadline to all the fences in the array.

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Christian König <[email protected]>
---
drivers/dma-buf/dma-fence-array.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
index 5c8a7084577b..9b3ce8948351 100644
--- a/drivers/dma-buf/dma-fence-array.c
+++ b/drivers/dma-buf/dma-fence-array.c
@@ -123,12 +123,23 @@ static void dma_fence_array_release(struct dma_fence *fence)
dma_fence_free(fence);
}

+static void dma_fence_array_set_deadline(struct dma_fence *fence,
+ ktime_t deadline)
+{
+ struct dma_fence_array *array = to_dma_fence_array(fence);
+ unsigned i;
+
+ for (i = 0; i < array->num_fences; ++i)
+ dma_fence_set_deadline(array->fences[i], deadline);
+}
+
const struct dma_fence_ops dma_fence_array_ops = {
.get_driver_name = dma_fence_array_get_driver_name,
.get_timeline_name = dma_fence_array_get_timeline_name,
.enable_signaling = dma_fence_array_enable_signaling,
.signaled = dma_fence_array_signaled,
.release = dma_fence_array_release,
+ .set_deadline = dma_fence_array_set_deadline,
};
EXPORT_SYMBOL(dma_fence_array_ops);

--
2.39.1


2023-02-28 22:58:58

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 03/16] dma-buf/fence-chain: Add fence deadline support

From: Rob Clark <[email protected]>

Propagate the deadline to all the fences in the chain.

v2: Use dma_fence_chain_contained [Tvrtko]

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Christian König <[email protected]> for this one.
---
drivers/dma-buf/dma-fence-chain.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c
index a0d920576ba6..9663ba1bb6ac 100644
--- a/drivers/dma-buf/dma-fence-chain.c
+++ b/drivers/dma-buf/dma-fence-chain.c
@@ -206,6 +206,17 @@ static void dma_fence_chain_release(struct dma_fence *fence)
dma_fence_free(fence);
}

+
+static void dma_fence_chain_set_deadline(struct dma_fence *fence,
+ ktime_t deadline)
+{
+ dma_fence_chain_for_each(fence, fence) {
+ struct dma_fence *f = dma_fence_chain_contained(fence);
+
+ dma_fence_set_deadline(f, deadline);
+ }
+}
+
const struct dma_fence_ops dma_fence_chain_ops = {
.use_64bit_seqno = true,
.get_driver_name = dma_fence_chain_get_driver_name,
@@ -213,6 +224,7 @@ const struct dma_fence_ops dma_fence_chain_ops = {
.enable_signaling = dma_fence_chain_enable_signaling,
.signaled = dma_fence_chain_signaled,
.release = dma_fence_chain_release,
+ .set_deadline = dma_fence_chain_set_deadline,
};
EXPORT_SYMBOL(dma_fence_chain_ops);

--
2.39.1


2023-02-28 22:59:01

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 04/16] dma-buf/dma-resv: Add a way to set fence deadline

From: Rob Clark <[email protected]>

Add a way to set a deadline on remaining resv fences according to the
requested usage.

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Christian König <[email protected]>
---
drivers/dma-buf/dma-resv.c | 22 ++++++++++++++++++++++
include/linux/dma-resv.h | 2 ++
2 files changed, 24 insertions(+)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 1c76aed8e262..2a594b754af1 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -684,6 +684,28 @@ long dma_resv_wait_timeout(struct dma_resv *obj, enum dma_resv_usage usage,
}
EXPORT_SYMBOL_GPL(dma_resv_wait_timeout);

+/**
+ * dma_resv_set_deadline - Set a deadline on reservation's objects fences
+ * @obj: the reservation object
+ * @usage: controls which fences to include, see enum dma_resv_usage.
+ * @deadline: the requested deadline (MONOTONIC)
+ *
+ * May be called without holding the dma_resv lock. Sets @deadline on
+ * all fences filtered by @usage.
+ */
+void dma_resv_set_deadline(struct dma_resv *obj, enum dma_resv_usage usage,
+ ktime_t deadline)
+{
+ struct dma_resv_iter cursor;
+ struct dma_fence *fence;
+
+ dma_resv_iter_begin(&cursor, obj, usage);
+ dma_resv_for_each_fence_unlocked(&cursor, fence) {
+ dma_fence_set_deadline(fence, deadline);
+ }
+ dma_resv_iter_end(&cursor);
+}
+EXPORT_SYMBOL_GPL(dma_resv_set_deadline);

/**
* dma_resv_test_signaled - Test if a reservation object's fences have been
diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
index 0637659a702c..8d0e34dad446 100644
--- a/include/linux/dma-resv.h
+++ b/include/linux/dma-resv.h
@@ -479,6 +479,8 @@ int dma_resv_get_singleton(struct dma_resv *obj, enum dma_resv_usage usage,
int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src);
long dma_resv_wait_timeout(struct dma_resv *obj, enum dma_resv_usage usage,
bool intr, unsigned long timeout);
+void dma_resv_set_deadline(struct dma_resv *obj, enum dma_resv_usage usage,
+ ktime_t deadline);
bool dma_resv_test_signaled(struct dma_resv *obj, enum dma_resv_usage usage);
void dma_resv_describe(struct dma_resv *obj, struct seq_file *seq);

--
2.39.1


2023-02-28 22:59:03

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 05/16] dma-buf/sync_file: Surface sync-file uABI

From: Rob Clark <[email protected]>

We had all of the internal driver APIs, but not the all important
userspace uABI, in the dma-buf doc. Fix that. And re-arrange the
comments slightly as otherwise the comments for the ioctl nr defines
would not show up.

Signed-off-by: Rob Clark <[email protected]>
---
Documentation/driver-api/dma-buf.rst | 10 ++++++--
include/uapi/linux/sync_file.h | 35 +++++++++++-----------------
2 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
index 183e480d8cea..ff3f8da296af 100644
--- a/Documentation/driver-api/dma-buf.rst
+++ b/Documentation/driver-api/dma-buf.rst
@@ -203,8 +203,8 @@ DMA Fence unwrap
.. kernel-doc:: include/linux/dma-fence-unwrap.h
:internal:

-DMA Fence uABI/Sync File
-~~~~~~~~~~~~~~~~~~~~~~~~
+DMA Fence Sync File
+~~~~~~~~~~~~~~~~~~~

.. kernel-doc:: drivers/dma-buf/sync_file.c
:export:
@@ -212,6 +212,12 @@ DMA Fence uABI/Sync File
.. kernel-doc:: include/linux/sync_file.h
:internal:

+DMA Fence Sync File uABI
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/uapi/linux/sync_file.h
+ :internal:
+
Indefinite DMA Fences
~~~~~~~~~~~~~~~~~~~~~

diff --git a/include/uapi/linux/sync_file.h b/include/uapi/linux/sync_file.h
index ee2dcfb3d660..eced40c204d7 100644
--- a/include/uapi/linux/sync_file.h
+++ b/include/uapi/linux/sync_file.h
@@ -16,12 +16,16 @@
#include <linux/types.h>

/**
- * struct sync_merge_data - data passed to merge ioctl
+ * struct sync_merge_data - SYNC_IOC_MERGE: merge two fences
* @name: name of new fence
* @fd2: file descriptor of second fence
* @fence: returns the fd of the new fence to userspace
* @flags: merge_data flags
* @pad: padding for 64-bit alignment, should always be zero
+ *
+ * Creates a new fence containing copies of the sync_pts in both
+ * the calling fd and sync_merge_data.fd2. Returns the new fence's
+ * fd in sync_merge_data.fence
*/
struct sync_merge_data {
char name[32];
@@ -34,8 +38,8 @@ struct sync_merge_data {
/**
* struct sync_fence_info - detailed fence information
* @obj_name: name of parent sync_timeline
-* @driver_name: name of driver implementing the parent
-* @status: status of the fence 0:active 1:signaled <0:error
+ * @driver_name: name of driver implementing the parent
+ * @status: status of the fence 0:active 1:signaled <0:error
* @flags: fence_info flags
* @timestamp_ns: timestamp of status change in nanoseconds
*/
@@ -48,14 +52,19 @@ struct sync_fence_info {
};

/**
- * struct sync_file_info - data returned from fence info ioctl
+ * struct sync_file_info - SYNC_IOC_FILE_INFO: get detailed information on a sync_file
* @name: name of fence
* @status: status of fence. 1: signaled 0:active <0:error
* @flags: sync_file_info flags
* @num_fences number of fences in the sync_file
* @pad: padding for 64-bit alignment, should always be zero
- * @sync_fence_info: pointer to array of structs sync_fence_info with all
+ * @sync_fence_info: pointer to array of struct &sync_fence_info with all
* fences in the sync_file
+ *
+ * Takes a struct sync_file_info. If num_fences is 0, the field is updated
+ * with the actual number of fences. If num_fences is > 0, the system will
+ * use the pointer provided on sync_fence_info to return up to num_fences of
+ * struct sync_fence_info, with detailed fence information.
*/
struct sync_file_info {
char name[32];
@@ -76,23 +85,7 @@ struct sync_file_info {
* no upstream users available.
*/

-/**
- * DOC: SYNC_IOC_MERGE - merge two fences
- *
- * Takes a struct sync_merge_data. Creates a new fence containing copies of
- * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the
- * new fence's fd in sync_merge_data.fence
- */
#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
-
-/**
- * DOC: SYNC_IOC_FILE_INFO - get detailed information on a sync_file
- *
- * Takes a struct sync_file_info. If num_fences is 0, the field is updated
- * with the actual number of fences. If num_fences is > 0, the system will
- * use the pointer provided on sync_fence_info to return up to num_fences of
- * struct sync_fence_info, with detailed fence information.
- */
#define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info)

#endif /* _UAPI_LINUX_SYNC_H */
--
2.39.1


2023-02-28 22:59:15

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 06/16] dma-buf/sync_file: Add SET_DEADLINE ioctl

From: Rob Clark <[email protected]>

The initial purpose is for igt tests, but this would also be useful for
compositors that wait until close to vblank deadline to make decisions
about which frame to show.

The igt tests can be found at:

https://gitlab.freedesktop.org/robclark/igt-gpu-tools/-/commits/fence-deadline

v2: Clarify the timebase, add link to igt tests
v3: Use u64 value in ns to express deadline.
v4: More doc

Signed-off-by: Rob Clark <[email protected]>
Acked-by: Pekka Paalanen <[email protected]>
---
drivers/dma-buf/dma-fence.c | 3 ++-
drivers/dma-buf/sync_file.c | 19 +++++++++++++++++++
include/uapi/linux/sync_file.h | 22 ++++++++++++++++++++++
3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index f177c56269bb..74e36f6d05b0 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -933,7 +933,8 @@ EXPORT_SYMBOL(dma_fence_wait_any_timeout);
* the GPU's devfreq to reduce frequency, when in fact the opposite is what is
* needed.
*
- * To this end, deadline hint(s) can be set on a &dma_fence via &dma_fence_set_deadline.
+ * To this end, deadline hint(s) can be set on a &dma_fence via &dma_fence_set_deadline
+ * (or indirectly via userspace facing ioctls like &sync_set_deadline).
* The deadline hint provides a way for the waiting driver, or userspace, to
* convey an appropriate sense of urgency to the signaling driver.
*
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index af57799c86ce..418021cfb87c 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -350,6 +350,22 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
return ret;
}

+static int sync_file_ioctl_set_deadline(struct sync_file *sync_file,
+ unsigned long arg)
+{
+ struct sync_set_deadline ts;
+
+ if (copy_from_user(&ts, (void __user *)arg, sizeof(ts)))
+ return -EFAULT;
+
+ if (ts.pad)
+ return -EINVAL;
+
+ dma_fence_set_deadline(sync_file->fence, ns_to_ktime(ts.deadline_ns));
+
+ return 0;
+}
+
static long sync_file_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
@@ -362,6 +378,9 @@ static long sync_file_ioctl(struct file *file, unsigned int cmd,
case SYNC_IOC_FILE_INFO:
return sync_file_ioctl_fence_info(sync_file, arg);

+ case SYNC_IOC_SET_DEADLINE:
+ return sync_file_ioctl_set_deadline(sync_file, arg);
+
default:
return -ENOTTY;
}
diff --git a/include/uapi/linux/sync_file.h b/include/uapi/linux/sync_file.h
index eced40c204d7..594b8bba7948 100644
--- a/include/uapi/linux/sync_file.h
+++ b/include/uapi/linux/sync_file.h
@@ -76,6 +76,27 @@ struct sync_file_info {
__u64 sync_fence_info;
};

+/**
+ * struct sync_set_deadline - SYNC_IOC_SET_DEADLINE - set a deadline hint on a fence
+ * @deadline_ns: absolute time of the deadline
+ * @pad: must be zero
+ *
+ * Allows userspace to set a deadline on a fence, see &dma_fence_set_deadline
+ *
+ * The timebase for the deadline is CLOCK_MONOTONIC (same as vblank). For
+ * example
+ *
+ * clock_gettime(CLOCK_MONOTONIC, &t);
+ * deadline_ns = (t.tv_sec * 1000000000L) + t.tv_nsec + ns_until_deadline
+ */
+struct sync_set_deadline {
+ __u64 deadline_ns;
+ /* Not strictly needed for alignment but gives some possibility
+ * for future extension:
+ */
+ __u64 pad;
+};
+
#define SYNC_IOC_MAGIC '>'

/**
@@ -87,5 +108,6 @@ struct sync_file_info {

#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
#define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info)
+#define SYNC_IOC_SET_DEADLINE _IOW(SYNC_IOC_MAGIC, 5, struct sync_set_deadline)

#endif /* _UAPI_LINUX_SYNC_H */
--
2.39.1


2023-02-28 22:59:19

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 07/16] dma-buf/sync_file: Support (E)POLLPRI

From: Rob Clark <[email protected]>

Allow userspace to use the EPOLLPRI/POLLPRI flag to indicate an urgent
wait (as opposed to a "housekeeping" wait to know when to cleanup after
some work has completed). Usermode components of GPU driver stacks
often poll() on fence fd's to know when it is safe to do things like
free or reuse a buffer, but they can also poll() on a fence fd when
waiting to read back results from the GPU. The EPOLLPRI/POLLPRI flag
lets the kernel differentiate these two cases.

Signed-off-by: Rob Clark <[email protected]>
---
drivers/dma-buf/sync_file.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index 418021cfb87c..cbe96295373b 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -192,6 +192,14 @@ static __poll_t sync_file_poll(struct file *file, poll_table *wait)
{
struct sync_file *sync_file = file->private_data;

+ /*
+ * The POLLPRI/EPOLLPRI flag can be used to signal that
+ * userspace wants the fence to signal ASAP, express this
+ * as an immediate deadline.
+ */
+ if (poll_requested_events(wait) & EPOLLPRI)
+ dma_fence_set_deadline(sync_file->fence, ktime_get());
+
poll_wait(file, &sync_file->wq, wait);

if (list_empty(&sync_file->cb.node) &&
--
2.39.1


2023-02-28 22:59:33

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 08/16] dma-buf/sw_sync: Add fence deadline support

From: Rob Clark <[email protected]>

This consists of simply storing the most recent deadline, and adding an
ioctl to retrieve the deadline. This can be used in conjunction with
the SET_DEADLINE ioctl on a fence fd for testing. Ie. create various
sw_sync fences, merge them into a fence-array, set deadline on the
fence-array and confirm that it is propagated properly to each fence.

v2: Switch UABI to express deadline as u64
v3: More verbose UAPI docs, show how to convert from timespec
v4: Better comments, track the soonest deadline, as a normal fence
implementation would, return an error if no deadline set.

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Christian König <[email protected]>
---
drivers/dma-buf/sw_sync.c | 81 ++++++++++++++++++++++++++++++++++++
drivers/dma-buf/sync_debug.h | 2 +
2 files changed, 83 insertions(+)

diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
index 348b3a9170fa..f53071bca3af 100644
--- a/drivers/dma-buf/sw_sync.c
+++ b/drivers/dma-buf/sw_sync.c
@@ -52,12 +52,33 @@ struct sw_sync_create_fence_data {
__s32 fence; /* fd of new fence */
};

+/**
+ * struct sw_sync_get_deadline - get the deadline hint of a sw_sync fence
+ * @deadline_ns: absolute time of the deadline
+ * @pad: must be zero
+ * @fence_fd: the sw_sync fence fd (in)
+ *
+ * Return the earliest deadline set on the fence. The timebase for the
+ * deadline is CLOCK_MONOTONIC (same as vblank). If there is no deadline
+ * set on the fence, this ioctl will return -ENOENT.
+ */
+struct sw_sync_get_deadline {
+ __u64 deadline_ns;
+ __u32 pad;
+ __s32 fence_fd;
+};
+
#define SW_SYNC_IOC_MAGIC 'W'

#define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0,\
struct sw_sync_create_fence_data)

#define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
+#define SW_SYNC_GET_DEADLINE _IOWR(SW_SYNC_IOC_MAGIC, 2, \
+ struct sw_sync_get_deadline)
+
+
+#define SW_SYNC_HAS_DEADLINE_BIT DMA_FENCE_FLAG_USER_BITS

static const struct dma_fence_ops timeline_fence_ops;

@@ -171,6 +192,22 @@ static void timeline_fence_timeline_value_str(struct dma_fence *fence,
snprintf(str, size, "%d", parent->value);
}

+static void timeline_fence_set_deadline(struct dma_fence *fence, ktime_t deadline)
+{
+ struct sync_pt *pt = dma_fence_to_sync_pt(fence);
+ unsigned long flags;
+
+ spin_lock_irqsave(fence->lock, flags);
+ if (test_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags)) {
+ if (ktime_before(deadline, pt->deadline))
+ pt->deadline = deadline;
+ } else {
+ pt->deadline = deadline;
+ set_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags);
+ }
+ spin_unlock_irqrestore(fence->lock, flags);
+}
+
static const struct dma_fence_ops timeline_fence_ops = {
.get_driver_name = timeline_fence_get_driver_name,
.get_timeline_name = timeline_fence_get_timeline_name,
@@ -179,6 +216,7 @@ static const struct dma_fence_ops timeline_fence_ops = {
.release = timeline_fence_release,
.fence_value_str = timeline_fence_value_str,
.timeline_value_str = timeline_fence_timeline_value_str,
+ .set_deadline = timeline_fence_set_deadline,
};

/**
@@ -387,6 +425,46 @@ static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg)
return 0;
}

+static int sw_sync_ioctl_get_deadline(struct sync_timeline *obj, unsigned long arg)
+{
+ struct sw_sync_get_deadline data;
+ struct dma_fence *fence;
+ struct sync_pt *pt;
+ int ret = 0;
+
+ if (copy_from_user(&data, (void __user *)arg, sizeof(data)))
+ return -EFAULT;
+
+ if (data.deadline_ns || data.pad)
+ return -EINVAL;
+
+ fence = sync_file_get_fence(data.fence_fd);
+ if (!fence)
+ return -EINVAL;
+
+ pt = dma_fence_to_sync_pt(fence);
+ if (!pt)
+ return -EINVAL;
+
+ spin_lock(fence->lock);
+ if (test_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags)) {
+ data.deadline_ns = ktime_to_ns(pt->deadline);
+ } else {
+ ret = -ENOENT;
+ }
+ spin_unlock(fence->lock);
+
+ dma_fence_put(fence);
+
+ if (ret)
+ return ret;
+
+ if (copy_to_user((void __user *)arg, &data, sizeof(data)))
+ return -EFAULT;
+
+ return 0;
+}
+
static long sw_sync_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
@@ -399,6 +477,9 @@ static long sw_sync_ioctl(struct file *file, unsigned int cmd,
case SW_SYNC_IOC_INC:
return sw_sync_ioctl_inc(obj, arg);

+ case SW_SYNC_GET_DEADLINE:
+ return sw_sync_ioctl_get_deadline(obj, arg);
+
default:
return -ENOTTY;
}
diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
index 6176e52ba2d7..2e0146d0bdbb 100644
--- a/drivers/dma-buf/sync_debug.h
+++ b/drivers/dma-buf/sync_debug.h
@@ -55,11 +55,13 @@ static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence)
* @base: base fence object
* @link: link on the sync timeline's list
* @node: node in the sync timeline's tree
+ * @deadline: the most recently set fence deadline
*/
struct sync_pt {
struct dma_fence base;
struct list_head link;
struct rb_node node;
+ ktime_t deadline;
};

extern const struct file_operations sw_sync_debugfs_fops;
--
2.39.1


2023-02-28 22:59:43

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 09/16] drm/scheduler: Add fence deadline support

As the finished fence is the one that is exposed to userspace, and
therefore the one that other operations, like atomic update, would
block on, we need to propagate the deadline from from the finished
fence to the actual hw fence.

v2: Split into drm_sched_fence_set_parent() (ckoenig)
v3: Ensure a thread calling drm_sched_fence_set_deadline_finished() sees
fence->parent set before drm_sched_fence_set_parent() does this
test_bit(DMA_FENCE_FLAG_HAS_DEADLINE_BIT).

Signed-off-by: Rob Clark <[email protected]>
Acked-by: Luben Tuikov <[email protected]>
---
drivers/gpu/drm/scheduler/sched_fence.c | 46 +++++++++++++++++++++++++
drivers/gpu/drm/scheduler/sched_main.c | 2 +-
include/drm/gpu_scheduler.h | 17 +++++++++
3 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c
index 7fd869520ef2..fe9c6468e440 100644
--- a/drivers/gpu/drm/scheduler/sched_fence.c
+++ b/drivers/gpu/drm/scheduler/sched_fence.c
@@ -123,6 +123,37 @@ static void drm_sched_fence_release_finished(struct dma_fence *f)
dma_fence_put(&fence->scheduled);
}

+static void drm_sched_fence_set_deadline_finished(struct dma_fence *f,
+ ktime_t deadline)
+{
+ struct drm_sched_fence *fence = to_drm_sched_fence(f);
+ struct dma_fence *parent;
+ unsigned long flags;
+
+ spin_lock_irqsave(&fence->lock, flags);
+
+ /* If we already have an earlier deadline, keep it: */
+ if (test_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags) &&
+ ktime_before(fence->deadline, deadline)) {
+ spin_unlock_irqrestore(&fence->lock, flags);
+ return;
+ }
+
+ fence->deadline = deadline;
+ set_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT, &f->flags);
+
+ spin_unlock_irqrestore(&fence->lock, flags);
+
+ /*
+ * smp_load_aquire() to ensure that if we are racing another
+ * thread calling drm_sched_fence_set_parent(), that we see
+ * the parent set before it calls test_bit(HAS_DEADLINE_BIT)
+ */
+ parent = smp_load_acquire(&fence->parent);
+ if (parent)
+ dma_fence_set_deadline(parent, deadline);
+}
+
static const struct dma_fence_ops drm_sched_fence_ops_scheduled = {
.get_driver_name = drm_sched_fence_get_driver_name,
.get_timeline_name = drm_sched_fence_get_timeline_name,
@@ -133,6 +164,7 @@ static const struct dma_fence_ops drm_sched_fence_ops_finished = {
.get_driver_name = drm_sched_fence_get_driver_name,
.get_timeline_name = drm_sched_fence_get_timeline_name,
.release = drm_sched_fence_release_finished,
+ .set_deadline = drm_sched_fence_set_deadline_finished,
};

struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f)
@@ -147,6 +179,20 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f)
}
EXPORT_SYMBOL(to_drm_sched_fence);

+void drm_sched_fence_set_parent(struct drm_sched_fence *s_fence,
+ struct dma_fence *fence)
+{
+ /*
+ * smp_store_release() to ensure another thread racing us
+ * in drm_sched_fence_set_deadline_finished() sees the
+ * fence's parent set before test_bit()
+ */
+ smp_store_release(&s_fence->parent, dma_fence_get(fence));
+ if (test_bit(DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT,
+ &s_fence->finished.flags))
+ dma_fence_set_deadline(fence, s_fence->deadline);
+}
+
struct drm_sched_fence *drm_sched_fence_alloc(struct drm_sched_entity *entity,
void *owner)
{
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 4e6ad6e122bc..007f98c48f8d 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -1019,7 +1019,7 @@ static int drm_sched_main(void *param)
drm_sched_fence_scheduled(s_fence);

if (!IS_ERR_OR_NULL(fence)) {
- s_fence->parent = dma_fence_get(fence);
+ drm_sched_fence_set_parent(s_fence, fence);
/* Drop for original kref_init of the fence */
dma_fence_put(fence);

diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index 9db9e5e504ee..99584e457153 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -41,6 +41,15 @@
*/
#define DRM_SCHED_FENCE_DONT_PIPELINE DMA_FENCE_FLAG_USER_BITS

+/**
+ * DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT - A fence deadline hint has been set
+ *
+ * Because we could have a deadline hint can be set before the backing hw
+ * fence is created, we need to keep track of whether a deadline has already
+ * been set.
+ */
+#define DRM_SCHED_FENCE_FLAG_HAS_DEADLINE_BIT (DMA_FENCE_FLAG_USER_BITS + 1)
+
enum dma_resv_usage;
struct dma_resv;
struct drm_gem_object;
@@ -280,6 +289,12 @@ struct drm_sched_fence {
*/
struct dma_fence finished;

+ /**
+ * @deadline: deadline set on &drm_sched_fence.finished which
+ * potentially needs to be propagated to &drm_sched_fence.parent
+ */
+ ktime_t deadline;
+
/**
* @parent: the fence returned by &drm_sched_backend_ops.run_job
* when scheduling the job on hardware. We signal the
@@ -568,6 +583,8 @@ void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
enum drm_sched_priority priority);
bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);

+void drm_sched_fence_set_parent(struct drm_sched_fence *s_fence,
+ struct dma_fence *fence);
struct drm_sched_fence *drm_sched_fence_alloc(
struct drm_sched_entity *s_entity, void *owner);
void drm_sched_fence_init(struct drm_sched_fence *fence,
--
2.39.1


2023-02-28 22:59:48

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 10/16] drm/syncobj: Add deadline support for syncobj waits

From: Rob Clark <[email protected]>

Add a new flag to let userspace provide a deadline as a hint for syncobj
and timeline waits. This gives a hint to the driver signaling the
backing fences about how soon userspace needs it to compete work, so it
can addjust GPU frequency accordingly. An immediate deadline can be
given to provide something equivalent to i915 "wait boost".

v2: Use absolute u64 ns value for deadline hint, drop cap and driver
feature flag in favor of allowing count_handles==0 as a way for
userspace to probe kernel for support of new flag
v3: More verbose comments about UAPI

Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/drm_syncobj.c | 64 ++++++++++++++++++++++++++++-------
include/uapi/drm/drm.h | 17 ++++++++++
2 files changed, 68 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index 0c2be8360525..a85e9464f07b 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -126,6 +126,11 @@
* synchronize between the two.
* This requirement is inherited from the Vulkan fence API.
*
+ * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE is set, the ioctl will also set
+ * a fence deadline hint on the backing fences before waiting, to provide the
+ * fence signaler with an appropriate sense of urgency. The deadline is
+ * specified as an absolute &CLOCK_MONOTONIC value in units of ns.
+ *
* Similarly, &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT takes an array of syncobj
* handles as well as an array of u64 points and does a host-side wait on all
* of syncobj fences at the given points simultaneously.
@@ -973,7 +978,8 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
uint32_t count,
uint32_t flags,
signed long timeout,
- uint32_t *idx)
+ uint32_t *idx,
+ ktime_t *deadline)
{
struct syncobj_wait_entry *entries;
struct dma_fence *fence;
@@ -1053,6 +1059,15 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
drm_syncobj_fence_add_wait(syncobjs[i], &entries[i]);
}

+ if (deadline) {
+ for (i = 0; i < count; ++i) {
+ fence = entries[i].fence;
+ if (!fence)
+ continue;
+ dma_fence_set_deadline(fence, *deadline);
+ }
+ }
+
do {
set_current_state(TASK_INTERRUPTIBLE);

@@ -1151,7 +1166,8 @@ static int drm_syncobj_array_wait(struct drm_device *dev,
struct drm_file *file_private,
struct drm_syncobj_wait *wait,
struct drm_syncobj_timeline_wait *timeline_wait,
- struct drm_syncobj **syncobjs, bool timeline)
+ struct drm_syncobj **syncobjs, bool timeline,
+ ktime_t *deadline)
{
signed long timeout = 0;
uint32_t first = ~0;
@@ -1162,7 +1178,8 @@ static int drm_syncobj_array_wait(struct drm_device *dev,
NULL,
wait->count_handles,
wait->flags,
- timeout, &first);
+ timeout, &first,
+ deadline);
if (timeout < 0)
return timeout;
wait->first_signaled = first;
@@ -1172,7 +1189,8 @@ static int drm_syncobj_array_wait(struct drm_device *dev,
u64_to_user_ptr(timeline_wait->points),
timeline_wait->count_handles,
timeline_wait->flags,
- timeout, &first);
+ timeout, &first,
+ deadline);
if (timeout < 0)
return timeout;
timeline_wait->first_signaled = first;
@@ -1243,17 +1261,22 @@ drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
{
struct drm_syncobj_wait *args = data;
struct drm_syncobj **syncobjs;
+ unsigned possible_flags;
+ ktime_t t, *tp = NULL;
int ret = 0;

if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
return -EOPNOTSUPP;

- if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
- DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
+ possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
+ DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
+ DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
+
+ if (args->flags & ~possible_flags)
return -EINVAL;

if (args->count_handles == 0)
- return -EINVAL;
+ return 0;

ret = drm_syncobj_array_find(file_private,
u64_to_user_ptr(args->handles),
@@ -1262,8 +1285,13 @@ drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
if (ret < 0)
return ret;

+ if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
+ t = ns_to_ktime(args->deadline_ns);
+ tp = &t;
+ }
+
ret = drm_syncobj_array_wait(dev, file_private,
- args, NULL, syncobjs, false);
+ args, NULL, syncobjs, false, tp);

drm_syncobj_array_free(syncobjs, args->count_handles);

@@ -1276,18 +1304,23 @@ drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
{
struct drm_syncobj_timeline_wait *args = data;
struct drm_syncobj **syncobjs;
+ unsigned possible_flags;
+ ktime_t t, *tp = NULL;
int ret = 0;

if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
return -EOPNOTSUPP;

- if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
- DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
- DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE))
+ possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
+ DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT |
+ DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE |
+ DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
+
+ if (args->flags & ~possible_flags)
return -EINVAL;

if (args->count_handles == 0)
- return -EINVAL;
+ return -0;

ret = drm_syncobj_array_find(file_private,
u64_to_user_ptr(args->handles),
@@ -1296,8 +1329,13 @@ drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
if (ret < 0)
return ret;

+ if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) {
+ t = ns_to_ktime(args->deadline_ns);
+ tp = &t;
+ }
+
ret = drm_syncobj_array_wait(dev, file_private,
- NULL, args, syncobjs, true);
+ NULL, args, syncobjs, true, tp);

drm_syncobj_array_free(syncobjs, args->count_handles);

diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index 642808520d92..bff0509ac8b6 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -887,6 +887,7 @@ struct drm_syncobj_transfer {
#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0)
#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT (1 << 1)
#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE (1 << 2) /* wait for time point to become available */
+#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE (1 << 3) /* set fence deadline based to deadline_ns */
struct drm_syncobj_wait {
__u64 handles;
/* absolute timeout */
@@ -895,6 +896,14 @@ struct drm_syncobj_wait {
__u32 flags;
__u32 first_signaled; /* only valid when not waiting all */
__u32 pad;
+ /**
+ * @deadline_ns - fence deadline hint
+ *
+ * Deadline hint, in absolute CLOCK_MONOTONIC, to set on backing
+ * fence(s) if the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE flag is
+ * set.
+ */
+ __u64 deadline_ns;
};

struct drm_syncobj_timeline_wait {
@@ -907,6 +916,14 @@ struct drm_syncobj_timeline_wait {
__u32 flags;
__u32 first_signaled; /* only valid when not waiting all */
__u32 pad;
+ /**
+ * @deadline_ns - fence deadline hint
+ *
+ * Deadline hint, in absolute CLOCK_MONOTONIC, to set on backing
+ * fence(s) if the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE flag is
+ * set.
+ */
+ __u64 deadline_ns;
};


--
2.39.1


2023-02-28 22:59:52

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 11/16] drm/vblank: Add helper to get next vblank time

From: Rob Clark <[email protected]>

Will be used in the next commit to set a deadline on fences that an
atomic update is waiting on.

v2: Calculate time at *start* of vblank period, not end
v3: Fix kbuild complaints

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Mario Kleiner <[email protected]>
---
drivers/gpu/drm/drm_vblank.c | 53 ++++++++++++++++++++++++++++++------
include/drm/drm_vblank.h | 1 +
2 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 2ff31717a3de..299fa2a19a90 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -844,10 +844,9 @@ bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc,
EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp);

/**
- * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
- * vblank interval
- * @dev: DRM device
- * @pipe: index of CRTC whose vblank timestamp to retrieve
+ * drm_crtc_get_last_vbltimestamp - retrieve raw timestamp for the most
+ * recent vblank interval
+ * @crtc: CRTC whose vblank timestamp to retrieve
* @tvblank: Pointer to target time which should receive the timestamp
* @in_vblank_irq:
* True when called from drm_crtc_handle_vblank(). Some drivers
@@ -865,10 +864,9 @@ EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp);
* True if timestamp is considered to be very precise, false otherwise.
*/
static bool
-drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
- ktime_t *tvblank, bool in_vblank_irq)
+drm_crtc_get_last_vbltimestamp(struct drm_crtc *crtc, ktime_t *tvblank,
+ bool in_vblank_irq)
{
- struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
bool ret = false;

/* Define requested maximum error on timestamps (nanoseconds). */
@@ -876,8 +874,6 @@ drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,

/* Query driver if possible and precision timestamping enabled. */
if (crtc && crtc->funcs->get_vblank_timestamp && max_error > 0) {
- struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
-
ret = crtc->funcs->get_vblank_timestamp(crtc, &max_error,
tvblank, in_vblank_irq);
}
@@ -891,6 +887,15 @@ drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
return ret;
}

+static bool
+drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
+ ktime_t *tvblank, bool in_vblank_irq)
+{
+ struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+
+ return drm_crtc_get_last_vbltimestamp(crtc, tvblank, in_vblank_irq);
+}
+
/**
* drm_crtc_vblank_count - retrieve "cooked" vblank counter value
* @crtc: which counter to retrieve
@@ -980,6 +985,36 @@ u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
}
EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);

+/**
+ * drm_crtc_next_vblank_start - calculate the time of the next vblank
+ * @crtc: the crtc for which to calculate next vblank time
+ * @vblanktime: pointer to time to receive the next vblank timestamp.
+ *
+ * Calculate the expected time of the start of the next vblank period,
+ * based on time of previous vblank and frame duration
+ */
+int drm_crtc_next_vblank_start(struct drm_crtc *crtc, ktime_t *vblanktime)
+{
+ unsigned int pipe = drm_crtc_index(crtc);
+ struct drm_vblank_crtc *vblank = &crtc->dev->vblank[pipe];
+ struct drm_display_mode *mode = &vblank->hwmode;
+ u64 vblank_start;
+
+ if (!vblank->framedur_ns || !vblank->linedur_ns)
+ return -EINVAL;
+
+ if (!drm_crtc_get_last_vbltimestamp(crtc, vblanktime, false))
+ return -EINVAL;
+
+ vblank_start = DIV_ROUND_DOWN_ULL(
+ (u64)vblank->framedur_ns * mode->crtc_vblank_start,
+ mode->crtc_vtotal);
+ *vblanktime = ktime_add(*vblanktime, ns_to_ktime(vblank_start));
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_crtc_next_vblank_start);
+
static void send_vblank_event(struct drm_device *dev,
struct drm_pending_vblank_event *e,
u64 seq, ktime_t now)
diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h
index 733a3e2d1d10..7f3957943dd1 100644
--- a/include/drm/drm_vblank.h
+++ b/include/drm/drm_vblank.h
@@ -230,6 +230,7 @@ bool drm_dev_has_vblank(const struct drm_device *dev);
u64 drm_crtc_vblank_count(struct drm_crtc *crtc);
u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
ktime_t *vblanktime);
+int drm_crtc_next_vblank_start(struct drm_crtc *crtc, ktime_t *vblanktime);
void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
struct drm_pending_vblank_event *e);
void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
--
2.39.1


2023-02-28 23:00:00

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 12/16] drm/atomic-helper: Set fence deadline for vblank

From: Rob Clark <[email protected]>

For an atomic commit updating a single CRTC (ie. a pageflip) calculate
the next vblank time, and inform the fence(s) of that deadline.

v2: Comment typo fix (danvet)

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/drm_atomic_helper.c | 36 +++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index d579fd8f7cb8..d8ee98ce2fc5 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1511,6 +1511,40 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
}
EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);

+/*
+ * For atomic updates which touch just a single CRTC, calculate the time of the
+ * next vblank, and inform all the fences of the deadline.
+ */
+static void set_fence_deadline(struct drm_device *dev,
+ struct drm_atomic_state *state)
+{
+ struct drm_crtc *crtc, *wait_crtc = NULL;
+ struct drm_crtc_state *new_crtc_state;
+ struct drm_plane *plane;
+ struct drm_plane_state *new_plane_state;
+ ktime_t vbltime;
+ int i;
+
+ for_each_new_crtc_in_state (state, crtc, new_crtc_state, i) {
+ if (wait_crtc)
+ return;
+ wait_crtc = crtc;
+ }
+
+ /* If no CRTCs updated, then nothing to do: */
+ if (!wait_crtc)
+ return;
+
+ if (drm_crtc_next_vblank_start(wait_crtc, &vbltime))
+ return;
+
+ for_each_new_plane_in_state (state, plane, new_plane_state, i) {
+ if (!new_plane_state->fence)
+ continue;
+ dma_fence_set_deadline(new_plane_state->fence, vbltime);
+ }
+}
+
/**
* drm_atomic_helper_wait_for_fences - wait for fences stashed in plane state
* @dev: DRM device
@@ -1540,6 +1574,8 @@ int drm_atomic_helper_wait_for_fences(struct drm_device *dev,
struct drm_plane_state *new_plane_state;
int i, ret;

+ set_fence_deadline(dev, state);
+
for_each_new_plane_in_state(state, plane, new_plane_state, i) {
if (!new_plane_state->fence)
continue;
--
2.39.1


2023-02-28 23:00:02

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 13/16] drm/msm: Add deadline based boost support

From: Rob Clark <[email protected]>

Track the nearest deadline on a fence timeline and set a timer to expire
shortly before to trigger boost if the fence has not yet been signaled.

v2: rebase

Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/msm/msm_fence.c | 74 +++++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/msm_fence.h | 20 +++++++++
2 files changed, 94 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_fence.c b/drivers/gpu/drm/msm/msm_fence.c
index 56641408ea74..51b461f32103 100644
--- a/drivers/gpu/drm/msm/msm_fence.c
+++ b/drivers/gpu/drm/msm/msm_fence.c
@@ -8,6 +8,35 @@

#include "msm_drv.h"
#include "msm_fence.h"
+#include "msm_gpu.h"
+
+static struct msm_gpu *fctx2gpu(struct msm_fence_context *fctx)
+{
+ struct msm_drm_private *priv = fctx->dev->dev_private;
+ return priv->gpu;
+}
+
+static enum hrtimer_restart deadline_timer(struct hrtimer *t)
+{
+ struct msm_fence_context *fctx = container_of(t,
+ struct msm_fence_context, deadline_timer);
+
+ kthread_queue_work(fctx2gpu(fctx)->worker, &fctx->deadline_work);
+
+ return HRTIMER_NORESTART;
+}
+
+static void deadline_work(struct kthread_work *work)
+{
+ struct msm_fence_context *fctx = container_of(work,
+ struct msm_fence_context, deadline_work);
+
+ /* If deadline fence has already passed, nothing to do: */
+ if (msm_fence_completed(fctx, fctx->next_deadline_fence))
+ return;
+
+ msm_devfreq_boost(fctx2gpu(fctx), 2);
+}


struct msm_fence_context *
@@ -36,6 +65,13 @@ msm_fence_context_alloc(struct drm_device *dev, volatile uint32_t *fenceptr,
fctx->completed_fence = fctx->last_fence;
*fctx->fenceptr = fctx->last_fence;

+ hrtimer_init(&fctx->deadline_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ fctx->deadline_timer.function = deadline_timer;
+
+ kthread_init_work(&fctx->deadline_work, deadline_work);
+
+ fctx->next_deadline = ktime_get();
+
return fctx;
}

@@ -62,6 +98,8 @@ void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
spin_lock_irqsave(&fctx->spinlock, flags);
if (fence_after(fence, fctx->completed_fence))
fctx->completed_fence = fence;
+ if (msm_fence_completed(fctx, fctx->next_deadline_fence))
+ hrtimer_cancel(&fctx->deadline_timer);
spin_unlock_irqrestore(&fctx->spinlock, flags);
}

@@ -92,10 +130,46 @@ static bool msm_fence_signaled(struct dma_fence *fence)
return msm_fence_completed(f->fctx, f->base.seqno);
}

+static void msm_fence_set_deadline(struct dma_fence *fence, ktime_t deadline)
+{
+ struct msm_fence *f = to_msm_fence(fence);
+ struct msm_fence_context *fctx = f->fctx;
+ unsigned long flags;
+ ktime_t now;
+
+ spin_lock_irqsave(&fctx->spinlock, flags);
+ now = ktime_get();
+
+ if (ktime_after(now, fctx->next_deadline) ||
+ ktime_before(deadline, fctx->next_deadline)) {
+ fctx->next_deadline = deadline;
+ fctx->next_deadline_fence =
+ max(fctx->next_deadline_fence, (uint32_t)fence->seqno);
+
+ /*
+ * Set timer to trigger boost 3ms before deadline, or
+ * if we are already less than 3ms before the deadline
+ * schedule boost work immediately.
+ */
+ deadline = ktime_sub(deadline, ms_to_ktime(3));
+
+ if (ktime_after(now, deadline)) {
+ kthread_queue_work(fctx2gpu(fctx)->worker,
+ &fctx->deadline_work);
+ } else {
+ hrtimer_start(&fctx->deadline_timer, deadline,
+ HRTIMER_MODE_ABS);
+ }
+ }
+
+ spin_unlock_irqrestore(&fctx->spinlock, flags);
+}
+
static const struct dma_fence_ops msm_fence_ops = {
.get_driver_name = msm_fence_get_driver_name,
.get_timeline_name = msm_fence_get_timeline_name,
.signaled = msm_fence_signaled,
+ .set_deadline = msm_fence_set_deadline,
};

struct dma_fence *
diff --git a/drivers/gpu/drm/msm/msm_fence.h b/drivers/gpu/drm/msm/msm_fence.h
index 7f1798c54cd1..cdaebfb94f5c 100644
--- a/drivers/gpu/drm/msm/msm_fence.h
+++ b/drivers/gpu/drm/msm/msm_fence.h
@@ -52,6 +52,26 @@ struct msm_fence_context {
volatile uint32_t *fenceptr;

spinlock_t spinlock;
+
+ /*
+ * TODO this doesn't really deal with multiple deadlines, like
+ * if userspace got multiple frames ahead.. OTOH atomic updates
+ * don't queue, so maybe that is ok
+ */
+
+ /** next_deadline: Time of next deadline */
+ ktime_t next_deadline;
+
+ /**
+ * next_deadline_fence:
+ *
+ * Fence value for next pending deadline. The deadline timer is
+ * canceled when this fence is signaled.
+ */
+ uint32_t next_deadline_fence;
+
+ struct hrtimer deadline_timer;
+ struct kthread_work deadline_work;
};

struct msm_fence_context * msm_fence_context_alloc(struct drm_device *dev,
--
2.39.1


2023-02-28 23:00:06

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 14/16] drm/msm: Add wait-boost support

From: Rob Clark <[email protected]>

Add a way for various userspace waits to signal urgency.

Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/msm/msm_drv.c | 12 ++++++++----
drivers/gpu/drm/msm/msm_gem.c | 5 +++++
include/uapi/drm/msm_drm.h | 14 ++++++++++++--
3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index aca48c868c14..f6764a86b2da 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -46,6 +46,7 @@
* - 1.8.0 - Add MSM_BO_CACHED_COHERENT for supported GPUs (a6xx)
* - 1.9.0 - Add MSM_SUBMIT_FENCE_SN_IN
* - 1.10.0 - Add MSM_SUBMIT_BO_NO_IMPLICIT
+ * - 1.11.0 - Add wait boost (MSM_WAIT_FENCE_BOOST, MSM_PREP_BOOST)
*/
#define MSM_VERSION_MAJOR 1
#define MSM_VERSION_MINOR 10
@@ -899,7 +900,7 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
}

static int wait_fence(struct msm_gpu_submitqueue *queue, uint32_t fence_id,
- ktime_t timeout)
+ ktime_t timeout, uint32_t flags)
{
struct dma_fence *fence;
int ret;
@@ -929,6 +930,9 @@ static int wait_fence(struct msm_gpu_submitqueue *queue, uint32_t fence_id,
if (!fence)
return 0;

+ if (flags & MSM_WAIT_FENCE_BOOST)
+ dma_fence_set_deadline(fence, ktime_get());
+
ret = dma_fence_wait_timeout(fence, true, timeout_to_jiffies(&timeout));
if (ret == 0) {
ret = -ETIMEDOUT;
@@ -949,8 +953,8 @@ static int msm_ioctl_wait_fence(struct drm_device *dev, void *data,
struct msm_gpu_submitqueue *queue;
int ret;

- if (args->pad) {
- DRM_ERROR("invalid pad: %08x\n", args->pad);
+ if (args->flags & ~MSM_WAIT_FENCE_FLAGS) {
+ DRM_ERROR("invalid flags: %08x\n", args->flags);
return -EINVAL;
}

@@ -961,7 +965,7 @@ static int msm_ioctl_wait_fence(struct drm_device *dev, void *data,
if (!queue)
return -ENOENT;

- ret = wait_fence(queue, args->fence, to_ktime(args->timeout));
+ ret = wait_fence(queue, args->fence, to_ktime(args->timeout), args->flags);

msm_submitqueue_put(queue);

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 1dee0d18abbb..dd4a0d773f6e 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -846,6 +846,11 @@ int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op, ktime_t *timeout)
op & MSM_PREP_NOSYNC ? 0 : timeout_to_jiffies(timeout);
long ret;

+ if (op & MSM_PREP_BOOST) {
+ dma_resv_set_deadline(obj->resv, dma_resv_usage_rw(write),
+ ktime_get());
+ }
+
ret = dma_resv_wait_timeout(obj->resv, dma_resv_usage_rw(write),
true, remain);
if (ret == 0)
diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h
index 329100016e7c..dbf0d6f43fa9 100644
--- a/include/uapi/drm/msm_drm.h
+++ b/include/uapi/drm/msm_drm.h
@@ -151,8 +151,13 @@ struct drm_msm_gem_info {
#define MSM_PREP_READ 0x01
#define MSM_PREP_WRITE 0x02
#define MSM_PREP_NOSYNC 0x04
+#define MSM_PREP_BOOST 0x08

-#define MSM_PREP_FLAGS (MSM_PREP_READ | MSM_PREP_WRITE | MSM_PREP_NOSYNC)
+#define MSM_PREP_FLAGS (MSM_PREP_READ | \
+ MSM_PREP_WRITE | \
+ MSM_PREP_NOSYNC | \
+ MSM_PREP_BOOST | \
+ 0)

struct drm_msm_gem_cpu_prep {
__u32 handle; /* in */
@@ -286,6 +291,11 @@ struct drm_msm_gem_submit {

};

+#define MSM_WAIT_FENCE_BOOST 0x00000001
+#define MSM_WAIT_FENCE_FLAGS ( \
+ MSM_WAIT_FENCE_BOOST | \
+ 0)
+
/* The normal way to synchronize with the GPU is just to CPU_PREP on
* a buffer if you need to access it from the CPU (other cmdstream
* submission from same or other contexts, PAGE_FLIP ioctl, etc, all
@@ -295,7 +305,7 @@ struct drm_msm_gem_submit {
*/
struct drm_msm_wait_fence {
__u32 fence; /* in */
- __u32 pad;
+ __u32 flags; /* in, bitmask of MSM_WAIT_FENCE_x */
struct drm_msm_timespec timeout; /* in */
__u32 queueid; /* in, submitqueue id */
};
--
2.39.1


2023-02-28 23:00:10

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 15/16] drm/msm/atomic: Switch to vblank_start helper

From: Rob Clark <[email protected]>

Drop our custom thing and switch to drm_crtc_next_vblank_start() for
calculating the time of the start of the next vblank period.

Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 15 ---------------
drivers/gpu/drm/msm/msm_atomic.c | 8 +++++---
drivers/gpu/drm/msm/msm_kms.h | 8 --------
3 files changed, 5 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index a683bd9b5a04..43996aecaf8c 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -411,20 +411,6 @@ static void dpu_kms_disable_commit(struct msm_kms *kms)
pm_runtime_put_sync(&dpu_kms->pdev->dev);
}

-static ktime_t dpu_kms_vsync_time(struct msm_kms *kms, struct drm_crtc *crtc)
-{
- struct drm_encoder *encoder;
-
- drm_for_each_encoder_mask(encoder, crtc->dev, crtc->state->encoder_mask) {
- ktime_t vsync_time;
-
- if (dpu_encoder_vsync_time(encoder, &vsync_time) == 0)
- return vsync_time;
- }
-
- return ktime_get();
-}
-
static void dpu_kms_prepare_commit(struct msm_kms *kms,
struct drm_atomic_state *state)
{
@@ -953,7 +939,6 @@ static const struct msm_kms_funcs kms_funcs = {
.irq = dpu_core_irq,
.enable_commit = dpu_kms_enable_commit,
.disable_commit = dpu_kms_disable_commit,
- .vsync_time = dpu_kms_vsync_time,
.prepare_commit = dpu_kms_prepare_commit,
.flush_commit = dpu_kms_flush_commit,
.wait_flush = dpu_kms_wait_flush,
diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
index 1686fbb611fd..c5e71c05f038 100644
--- a/drivers/gpu/drm/msm/msm_atomic.c
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -186,8 +186,7 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state)
struct msm_kms *kms = priv->kms;
struct drm_crtc *async_crtc = NULL;
unsigned crtc_mask = get_crtc_mask(state);
- bool async = kms->funcs->vsync_time &&
- can_do_async(state, &async_crtc);
+ bool async = can_do_async(state, &async_crtc);

trace_msm_atomic_commit_tail_start(async, crtc_mask);

@@ -231,7 +230,9 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state)

kms->pending_crtc_mask |= crtc_mask;

- vsync_time = kms->funcs->vsync_time(kms, async_crtc);
+ if (drm_crtc_next_vblank_start(async_crtc, &vsync_time))
+ goto fallback;
+
wakeup_time = ktime_sub(vsync_time, ms_to_ktime(1));

msm_hrtimer_queue_work(&timer->work, wakeup_time,
@@ -253,6 +254,7 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state)
return;
}

+fallback:
/*
* If there is any async flush pending on updated crtcs, fold
* them into the current flush.
diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index f8ed7588928c..086a3f1ff956 100644
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -59,14 +59,6 @@ struct msm_kms_funcs {
void (*enable_commit)(struct msm_kms *kms);
void (*disable_commit)(struct msm_kms *kms);

- /**
- * If the kms backend supports async commit, it should implement
- * this method to return the time of the next vsync. This is
- * used to determine a time slightly before vsync, for the async
- * commit timer to run and complete an async commit.
- */
- ktime_t (*vsync_time)(struct msm_kms *kms, struct drm_crtc *crtc);
-
/**
* Prepare for atomic commit. This is called after any previous
* (async or otherwise) commit has completed.
--
2.39.1


2023-02-28 23:03:37

by Rob Clark

[permalink] [raw]
Subject: [PATCH v8 16/16] drm/i915: Add deadline based boost support

From: Rob Clark <[email protected]>

v2: rebase

Signed-off-by: Rob Clark <[email protected]>
---
drivers/gpu/drm/i915/i915_request.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 7503dcb9043b..44491e7e214c 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -97,6 +97,25 @@ static bool i915_fence_enable_signaling(struct dma_fence *fence)
return i915_request_enable_breadcrumb(to_request(fence));
}

+static void i915_fence_set_deadline(struct dma_fence *fence, ktime_t deadline)
+{
+ struct i915_request *rq = to_request(fence);
+
+ if (i915_request_completed(rq))
+ return;
+
+ if (i915_request_started(rq))
+ return;
+
+ /*
+ * TODO something more clever for deadlines that are in the
+ * future. I think probably track the nearest deadline in
+ * rq->timeline and set timer to trigger boost accordingly?
+ */
+
+ intel_rps_boost(rq);
+}
+
static signed long i915_fence_wait(struct dma_fence *fence,
bool interruptible,
signed long timeout)
@@ -182,6 +201,7 @@ const struct dma_fence_ops i915_fence_ops = {
.signaled = i915_fence_signaled,
.wait = i915_fence_wait,
.release = i915_fence_release,
+ .set_deadline = i915_fence_set_deadline,
};

static void irq_execute_cb(struct irq_work *wrk)
--
2.39.1


2023-03-01 08:28:19

by Bagas Sanjaya

[permalink] [raw]
Subject: Re: [PATCH v8 01/16] dma-buf/dma-fence: Add deadline awareness

On 3/1/23 05:58, Rob Clark wrote:
> From: Rob Clark <[email protected]>
>
> Add a way to hint to the fence signaler of an upcoming deadline, such as
> vblank, which the fence waiter would prefer not to miss. This is to aid
> the fence signaler in making power management decisions, like boosting
> frequency as the deadline approaches and awareness of missing deadlines
> so that can be factored in to the frequency scaling.
>
> v2: Drop dma_fence::deadline and related logic to filter duplicate
> deadlines, to avoid increasing dma_fence size. The fence-context
> implementation will need similar logic to track deadlines of all
> the fences on the same timeline. [ckoenig]
> v3: Clarify locking wrt. set_deadline callback
> v4: Clarify in docs comment that this is a hint
> v5: Drop DMA_FENCE_FLAG_HAS_DEADLINE_BIT.
> v6: More docs
> v7: Fix typo, clarify past deadlines
>
> Signed-off-by: Rob Clark <[email protected]>
> Reviewed-by: Christian König <[email protected]>
> Acked-by: Pekka Paalanen <[email protected]>

I have given my Reviewed-by from v7 [1], but it didn't get picked up,
thus giving it again:

Reviewed-by: Bagas Sanjaya <[email protected]>

Thanks.

[1]: https://lore.kernel.org/linux-doc/Y%[email protected]/

--
An old man doll... just what I always wanted! - Clara


2023-03-01 08:52:38

by Pekka Paalanen

[permalink] [raw]
Subject: Re: [PATCH v8 05/16] dma-buf/sync_file: Surface sync-file uABI

On Tue, 28 Feb 2023 14:58:09 -0800
Rob Clark <[email protected]> wrote:

> From: Rob Clark <[email protected]>
>
> We had all of the internal driver APIs, but not the all important
> userspace uABI, in the dma-buf doc. Fix that. And re-arrange the
> comments slightly as otherwise the comments for the ioctl nr defines
> would not show up.
>
> Signed-off-by: Rob Clark <[email protected]>
> ---
> Documentation/driver-api/dma-buf.rst | 10 ++++++--
> include/uapi/linux/sync_file.h | 35 +++++++++++-----------------
> 2 files changed, 22 insertions(+), 23 deletions(-)
>

Sounds good.
Acked-by: Pekka Paalanen <[email protected]>


Thanks,
pq

> diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
> index 183e480d8cea..ff3f8da296af 100644
> --- a/Documentation/driver-api/dma-buf.rst
> +++ b/Documentation/driver-api/dma-buf.rst
> @@ -203,8 +203,8 @@ DMA Fence unwrap
> .. kernel-doc:: include/linux/dma-fence-unwrap.h
> :internal:
>
> -DMA Fence uABI/Sync File
> -~~~~~~~~~~~~~~~~~~~~~~~~
> +DMA Fence Sync File
> +~~~~~~~~~~~~~~~~~~~
>
> .. kernel-doc:: drivers/dma-buf/sync_file.c
> :export:
> @@ -212,6 +212,12 @@ DMA Fence uABI/Sync File
> .. kernel-doc:: include/linux/sync_file.h
> :internal:
>
> +DMA Fence Sync File uABI
> +~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +.. kernel-doc:: include/uapi/linux/sync_file.h
> + :internal:
> +
> Indefinite DMA Fences
> ~~~~~~~~~~~~~~~~~~~~~
>
> diff --git a/include/uapi/linux/sync_file.h b/include/uapi/linux/sync_file.h
> index ee2dcfb3d660..eced40c204d7 100644
> --- a/include/uapi/linux/sync_file.h
> +++ b/include/uapi/linux/sync_file.h
> @@ -16,12 +16,16 @@
> #include <linux/types.h>
>
> /**
> - * struct sync_merge_data - data passed to merge ioctl
> + * struct sync_merge_data - SYNC_IOC_MERGE: merge two fences
> * @name: name of new fence
> * @fd2: file descriptor of second fence
> * @fence: returns the fd of the new fence to userspace
> * @flags: merge_data flags
> * @pad: padding for 64-bit alignment, should always be zero
> + *
> + * Creates a new fence containing copies of the sync_pts in both
> + * the calling fd and sync_merge_data.fd2. Returns the new fence's
> + * fd in sync_merge_data.fence
> */
> struct sync_merge_data {
> char name[32];
> @@ -34,8 +38,8 @@ struct sync_merge_data {
> /**
> * struct sync_fence_info - detailed fence information
> * @obj_name: name of parent sync_timeline
> -* @driver_name: name of driver implementing the parent
> -* @status: status of the fence 0:active 1:signaled <0:error
> + * @driver_name: name of driver implementing the parent
> + * @status: status of the fence 0:active 1:signaled <0:error
> * @flags: fence_info flags
> * @timestamp_ns: timestamp of status change in nanoseconds
> */
> @@ -48,14 +52,19 @@ struct sync_fence_info {
> };
>
> /**
> - * struct sync_file_info - data returned from fence info ioctl
> + * struct sync_file_info - SYNC_IOC_FILE_INFO: get detailed information on a sync_file
> * @name: name of fence
> * @status: status of fence. 1: signaled 0:active <0:error
> * @flags: sync_file_info flags
> * @num_fences number of fences in the sync_file
> * @pad: padding for 64-bit alignment, should always be zero
> - * @sync_fence_info: pointer to array of structs sync_fence_info with all
> + * @sync_fence_info: pointer to array of struct &sync_fence_info with all
> * fences in the sync_file
> + *
> + * Takes a struct sync_file_info. If num_fences is 0, the field is updated
> + * with the actual number of fences. If num_fences is > 0, the system will
> + * use the pointer provided on sync_fence_info to return up to num_fences of
> + * struct sync_fence_info, with detailed fence information.
> */
> struct sync_file_info {
> char name[32];
> @@ -76,23 +85,7 @@ struct sync_file_info {
> * no upstream users available.
> */
>
> -/**
> - * DOC: SYNC_IOC_MERGE - merge two fences
> - *
> - * Takes a struct sync_merge_data. Creates a new fence containing copies of
> - * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the
> - * new fence's fd in sync_merge_data.fence
> - */
> #define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
> -
> -/**
> - * DOC: SYNC_IOC_FILE_INFO - get detailed information on a sync_file
> - *
> - * Takes a struct sync_file_info. If num_fences is 0, the field is updated
> - * with the actual number of fences. If num_fences is > 0, the system will
> - * use the pointer provided on sync_fence_info to return up to num_fences of
> - * struct sync_fence_info, with detailed fence information.
> - */
> #define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info)
>
> #endif /* _UAPI_LINUX_SYNC_H */


Attachments:
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2023-03-01 08:57:26

by Pekka Paalanen

[permalink] [raw]
Subject: Re: [PATCH v8 08/16] dma-buf/sw_sync: Add fence deadline support

On Tue, 28 Feb 2023 14:58:12 -0800
Rob Clark <[email protected]> wrote:

> From: Rob Clark <[email protected]>
>
> This consists of simply storing the most recent deadline, and adding an
> ioctl to retrieve the deadline. This can be used in conjunction with
> the SET_DEADLINE ioctl on a fence fd for testing. Ie. create various
> sw_sync fences, merge them into a fence-array, set deadline on the
> fence-array and confirm that it is propagated properly to each fence.
>
> v2: Switch UABI to express deadline as u64
> v3: More verbose UAPI docs, show how to convert from timespec
> v4: Better comments, track the soonest deadline, as a normal fence
> implementation would, return an error if no deadline set.
>
> Signed-off-by: Rob Clark <[email protected]>
> Reviewed-by: Christian König <[email protected]>
> ---
> drivers/dma-buf/sw_sync.c | 81 ++++++++++++++++++++++++++++++++++++
> drivers/dma-buf/sync_debug.h | 2 +
> 2 files changed, 83 insertions(+)
>
> diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
> index 348b3a9170fa..f53071bca3af 100644
> --- a/drivers/dma-buf/sw_sync.c
> +++ b/drivers/dma-buf/sw_sync.c
> @@ -52,12 +52,33 @@ struct sw_sync_create_fence_data {
> __s32 fence; /* fd of new fence */
> };
>
> +/**
> + * struct sw_sync_get_deadline - get the deadline hint of a sw_sync fence
> + * @deadline_ns: absolute time of the deadline
> + * @pad: must be zero
> + * @fence_fd: the sw_sync fence fd (in)
> + *
> + * Return the earliest deadline set on the fence. The timebase for the
> + * deadline is CLOCK_MONOTONIC (same as vblank). If there is no deadline
> + * set on the fence, this ioctl will return -ENOENT.
> + */
> +struct sw_sync_get_deadline {
> + __u64 deadline_ns;
> + __u32 pad;
> + __s32 fence_fd;
> +};

Sounds good.

> diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
> index 6176e52ba2d7..2e0146d0bdbb 100644
> --- a/drivers/dma-buf/sync_debug.h
> +++ b/drivers/dma-buf/sync_debug.h
> @@ -55,11 +55,13 @@ static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence)
> * @base: base fence object
> * @link: link on the sync timeline's list
> * @node: node in the sync timeline's tree
> + * @deadline: the most recently set fence deadline

Now it's the earliest deadline.

> */
> struct sync_pt {
> struct dma_fence base;
> struct list_head link;
> struct rb_node node;
> + ktime_t deadline;
> };
>
> extern const struct file_operations sw_sync_debugfs_fops;

Acked-by: Pekka Paalanen <[email protected]>


Thanks,
pq


Attachments:
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2023-03-02 03:51:08

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH v8 05/16] dma-buf/sync_file: Surface sync-file uABI

Hi Rob,

I love your patch! Perhaps something to improve:

[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on drm-intel/for-linux-next-fixes drm/drm-next linus/master v6.2 next-20230301]
[cannot apply to drm-misc/drm-misc-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#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Rob-Clark/dma-buf-dma-fence-Add-deadline-awareness/20230301-070358
base: git://anongit.freedesktop.org/drm-intel for-linux-next
patch link: https://lore.kernel.org/r/20230228225833.2920879-6-robdclark%40gmail.com
patch subject: [PATCH v8 05/16] dma-buf/sync_file: Surface sync-file uABI
reproduce:
# https://github.com/intel-lab-lkp/linux/commit/b13821931cc3898065e4264fad78bad23c7d2208
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Rob-Clark/dma-buf-dma-fence-Add-deadline-awareness/20230301-070358
git checkout b13821931cc3898065e4264fad78bad23c7d2208
make menuconfig
# enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
make htmldocs

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
| Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

>> ./include/uapi/linux/sync_file.h:82: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst

vim +82 ./include/uapi/linux/sync_file.h

64907b94dab947 drivers/staging/android/uapi/sync.h Colin Cross 2014-02-17 80
2d75c88fefb228 drivers/staging/android/uapi/sync.h Gustavo Padovan 2016-04-26 81 /**
2d75c88fefb228 drivers/staging/android/uapi/sync.h Gustavo Padovan 2016-04-26 @82 * Opcodes 0, 1 and 2 were burned during a API change to avoid users of the
2d75c88fefb228 drivers/staging/android/uapi/sync.h Gustavo Padovan 2016-04-26 83 * old API to get weird errors when trying to handling sync_files. The API
2d75c88fefb228 drivers/staging/android/uapi/sync.h Gustavo Padovan 2016-04-26 84 * change happened during the de-stage of the Sync Framework when there was
2d75c88fefb228 drivers/staging/android/uapi/sync.h Gustavo Padovan 2016-04-26 85 * no upstream users available.
2d75c88fefb228 drivers/staging/android/uapi/sync.h Gustavo Padovan 2016-04-26 86 */
2d75c88fefb228 drivers/staging/android/uapi/sync.h Gustavo Padovan 2016-04-26 87

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