drm/panfrost: Add cycle counter job requirement

Extend the uAPI with a new job requirement flag for cycle
counters. This requirement is used by userland to indicate that a job
requires cycle counters or system timestamp to be propagated. (for use
with write value timestamp jobs)

We cannot enable cycle counters unconditionally as this would result in
an increase of GPU power consumption. As a result, they should be left
off unless required by the application.

If a job requires cycle counters or system timestamps propagation, we
must enable cycle counting before issuing a job and disable it right
after the job completes.

Since this extends the uAPI and because userland needs a way to advertise
features like VK_KHR_shader_clock conditionally, we bumps the driver
minor version.

v2:
- Rework commit message
- Squash uAPI changes and implementation in this commit
- Simplify changes based on Steven Price comments

v3:
- Add Steven Price r-b
- Fix a codestyle issue

Signed-off-by: Mary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240819080224.24914-3-mary.guillemard@collabora.com

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 790c4ad311437ea5a82974f78901dc2ad8eedba4..04d615df52590c1477569e663bb7961af2cfe10a 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -25,6 +25,8 @@
 #include "panfrost_gpu.h"
 #include "panfrost_perfcnt.h"
 
+#define JOB_REQUIREMENTS (PANFROST_JD_REQ_FS | PANFROST_JD_REQ_CYCLE_COUNT)
+
 static bool unstable_ioctls;
 module_param_unsafe(unstable_ioctls, bool, 0600);
 
@@ -282,7 +284,7 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data,
        if (!args->jc)
                return -EINVAL;
 
-       if (args->requirements && args->requirements != PANFROST_JD_REQ_FS)
+       if (args->requirements & ~JOB_REQUIREMENTS)
                return -EINVAL;
 
        if (args->out_sync > 0) {
@@ -621,6 +623,8 @@ static const struct file_operations panfrost_drm_driver_fops = {
  * - 1.0 - initial interface
  * - 1.1 - adds HEAP and NOEXEC flags for CREATE_BO
  * - 1.2 - adds AFBC_FEATURES query
+ * - 1.3 - adds JD_REQ_CYCLE_COUNT job requirement for SUBMIT
+ *       - adds SYSTEM_TIMESTAMP and SYSTEM_TIMESTAMP_FREQUENCY queries
  */
 static const struct drm_driver panfrost_drm_driver = {
        .driver_features        = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ,
@@ -634,7 +638,7 @@ static const struct drm_driver panfrost_drm_driver = {
        .desc                   = "panfrost DRM",
        .date                   = "20180908",
        .major                  = 1,
-       .minor                  = 2,
+       .minor                  = 3,
 
        .gem_create_object      = panfrost_gem_create_object,
        .gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,

diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index df49d37d0e7eb0fec3b2ba5fbe45e542d23ef201..3ad131eb66577bd17ab528b4a5595dedc0d2b759 100644 (file)
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -159,16 +159,17 @@ panfrost_dequeue_job(struct panfrost_device *pfdev, int slot)
        struct panfrost_job *job = pfdev->jobs[slot][0];
 
        WARN_ON(!job);
-       if (job->is_profiled) {
-               if (job->engine_usage) {
-                       job->engine_usage->elapsed_ns[slot] +=
-                               ktime_to_ns(ktime_sub(ktime_get(), job->start_time));
-                       job->engine_usage->cycles[slot] +=
-                               panfrost_cycle_counter_read(pfdev) - job->start_cycles;
-               }
-               panfrost_cycle_counter_put(job->pfdev);
+
+       if (job->is_profiled && job->engine_usage) {
+               job->engine_usage->elapsed_ns[slot] +=
+                       ktime_to_ns(ktime_sub(ktime_get(), job->start_time));
+               job->engine_usage->cycles[slot] +=
+                       panfrost_cycle_counter_read(pfdev) - job->start_cycles;
        }
 
+       if (job->requirements & PANFROST_JD_REQ_CYCLE_COUNT || job->is_profiled)
+               panfrost_cycle_counter_put(pfdev);
+
        pfdev->jobs[slot][0] = pfdev->jobs[slot][1];
        pfdev->jobs[slot][1] = NULL;
 
@@ -243,9 +244,13 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
        subslot = panfrost_enqueue_job(pfdev, js, job);
        /* Don't queue the job if a reset is in progress */
        if (!atomic_read(&pfdev->reset.pending)) {
-               if (pfdev->profile_mode) {
+               job->is_profiled = pfdev->profile_mode;
+
+               if (job->requirements & PANFROST_JD_REQ_CYCLE_COUNT ||
+                   job->is_profiled)
                        panfrost_cycle_counter_get(pfdev);
-                       job->is_profiled = true;
+
+               if (job->is_profiled) {
                        job->start_time = ktime_get();
                        job->start_cycles = panfrost_cycle_counter_read(pfdev);
                }
@@ -693,7 +698,8 @@ panfrost_reset(struct panfrost_device *pfdev,
        spin_lock(&pfdev->js->job_lock);
        for (i = 0; i < NUM_JOB_SLOTS; i++) {
                for (j = 0; j < ARRAY_SIZE(pfdev->jobs[0]) && pfdev->jobs[i][j]; j++) {
-                       if (pfdev->jobs[i][j]->is_profiled)
+                       if (pfdev->jobs[i][j]->requirements & PANFROST_JD_REQ_CYCLE_COUNT ||
+                           pfdev->jobs[i][j]->is_profiled)
                                panfrost_cycle_counter_put(pfdev->jobs[i][j]->pfdev);
                        pm_runtime_put_noidle(pfdev->dev);
                        panfrost_devfreq_record_idle(&pfdev->pfdevfreq);

diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
index 52b050e2b660429aaff3c04c73f45b9006f8aa1d..568724be6628d3c6155aa38f0468964af16f698f 100644 (file)
--- a/include/uapi/drm/panfrost_drm.h
+++ b/include/uapi/drm/panfrost_drm.h
@@ -40,6 +40,7 @@ extern "C" {
 #define DRM_IOCTL_PANFROST_PERFCNT_DUMP                DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_PERFCNT_DUMP, struct drm_panfrost_perfcnt_dump)
 
 #define PANFROST_JD_REQ_FS (1 << 0)
+#define PANFROST_JD_REQ_CYCLE_COUNT (1 << 1)
 /**
  * struct drm_panfrost_submit - ioctl argument for submitting commands to the 3D
  * engine.