The sampler must disable and re-enable counter sampling around suspends, and must re-program the FW interface after a reset to avoid losing data. Additionally, if a request was pending before the reset and it was not acked, the reset will have cleared it, so we toggle the flag and re-request a sample.
Signed-off-by: Lukas Zapolskas <[email protected]> --- drivers/gpu/drm/panthor/panthor_device.c | 8 ++- drivers/gpu/drm/panthor/panthor_perf.c | 83 ++++++++++++++++++++++++++++++++ drivers/gpu/drm/panthor/panthor_perf.h | 6 +++ 3 files changed, 96 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c index 535383ef629f..c842480472ac 100644 --- a/drivers/gpu/drm/panthor/panthor_device.c +++ b/drivers/gpu/drm/panthor/panthor_device.c @@ -138,6 +138,7 @@ static void panthor_device_reset_work(struct work_struct *work) if (!drm_dev_enter(&ptdev->base, &cookie)) return; + panthor_perf_pre_reset(ptdev); panthor_sched_pre_reset(ptdev); panthor_fw_pre_reset(ptdev, true); panthor_mmu_pre_reset(ptdev); @@ -147,6 +148,8 @@ static void panthor_device_reset_work(struct work_struct *work) ret = panthor_fw_post_reset(ptdev); atomic_set(&ptdev->reset.pending, 0); panthor_sched_post_reset(ptdev, ret != 0); + if (!ret) + panthor_perf_post_reset(ptdev); drm_dev_exit(cookie); if (ret) { @@ -539,8 +542,10 @@ int panthor_device_resume(struct device *dev) ret = panthor_device_resume_hw_components(ptdev); } - if (!ret) + if (!ret) { panthor_sched_resume(ptdev); + panthor_perf_resume(ptdev); + } drm_dev_exit(cookie); @@ -604,6 +609,7 @@ int panthor_device_suspend(struct device *dev) /* We prepare everything as if we were resetting the GPU. * The end of the reset will happen in the resume path though. */ + panthor_perf_suspend(ptdev); panthor_sched_suspend(ptdev); panthor_fw_suspend(ptdev); panthor_mmu_suspend(ptdev); diff --git a/drivers/gpu/drm/panthor/panthor_perf.c b/drivers/gpu/drm/panthor/panthor_perf.c index c66ad658a95d..28b02003f9f9 100644 --- a/drivers/gpu/drm/panthor/panthor_perf.c +++ b/drivers/gpu/drm/panthor/panthor_perf.c @@ -1798,6 +1798,57 @@ int panthor_perf_session_sample(struct panthor_file *pfile, u32 handle, u64 user return err; } +/** + * panthor_perf_suspend - Prepare the performance counter subsystem for system suspend. + * @ptdev: Panthor device. + * + * Indicate to the performance counters that the system is suspending. + * + * This function must not be used to handle MCU power state transitions: just before MCU goes + * from on to any inactive state, an automatic sample will be performed by the firmware, and + * the performance counter firmware state will be restored on warm boot. + * + */ +void panthor_perf_suspend(struct panthor_device *ptdev) +{ + struct panthor_perf *perf = ptdev->perf; + int ret; + + if (!perf) + return; + + guard(mutex)(&perf->op_lock); + + ret = perf_disable(perf); + + if (ret) + drm_warn(&ptdev->base, "Could not stop sampling before suspend, err = %d", ret); +} + +/** + * panthor_perf_resume - Resume the performance counter subsystem after system resumption. + * @ptdev: Panthor device. + * + * Indicate to the performance counters that the system has resumed. This must not be used + * to handle MCU state transitions, for the same reasons as detailed in the kerneldoc for + * @panthor_perf_suspend. + */ +void panthor_perf_resume(struct panthor_device *ptdev) +{ + struct panthor_perf *perf = ptdev->perf; + int ret; + + if (!perf) + return; + + guard(mutex)(&perf->op_lock); + + ret = perf_enable(perf); + + if (ret) + drm_warn(&ptdev->base, "Could not resume sampling, err = %d", ret); +} + /** * panthor_perf_unplug - Terminate the performance counter subsystem. * @ptdev: Panthor device. @@ -1868,3 +1919,35 @@ void panthor_perf_pool_destroy(struct panthor_file *pfile) pfile->sessions = NULL; } + +void panthor_perf_pre_reset(struct panthor_device *ptdev) +{ + if (!ptdev->perf) + return; + + guard(mutex)(&ptdev->perf->op_lock); + + perf_disable(ptdev->perf); +} + +void panthor_perf_post_reset(struct panthor_device *ptdev) +{ + bool rerequest = false; + + if (!ptdev->perf) + return; + + guard(mutex)(&ptdev->perf->op_lock); + + perf_enable(ptdev->perf); + + scoped_guard(spinlock_irqsave, &ptdev->perf->pend_lock) { + rerequest = ptdev->perf->fw_sample_requested; + + if (rerequest) + ptdev->perf->fw_sample_requested = false; + } + + if (rerequest) + perf_fw_request_sample(ptdev->perf); +} diff --git a/drivers/gpu/drm/panthor/panthor_perf.h b/drivers/gpu/drm/panthor/panthor_perf.h index 0e1172dbae39..e4a323fe6f0d 100644 --- a/drivers/gpu/drm/panthor/panthor_perf.h +++ b/drivers/gpu/drm/panthor/panthor_perf.h @@ -18,6 +18,8 @@ int panthor_perf_pool_create(struct panthor_file *pfile); void panthor_perf_pool_destroy(struct panthor_file *pfile); int panthor_perf_init(struct panthor_device *ptdev); +void panthor_perf_suspend(struct panthor_device *ptdev); +void panthor_perf_resume(struct panthor_device *ptdev); void panthor_perf_unplug(struct panthor_device *ptdev); int panthor_perf_session_create(struct drm_file *file, @@ -30,5 +32,9 @@ int panthor_perf_session_sample(struct panthor_file *pfile, unsigned int handle, void panthor_perf_report_irq(struct panthor_device *ptdev, u32 status); +void panthor_perf_pre_reset(struct panthor_device *ptdev); + +void panthor_perf_post_reset(struct panthor_device *ptdev); + #endif /* __PANTHOR_PERF_H__ */ -- 2.43.0
