Right now, if there's a HW reset and an HWPerf session is active, panfrost_mmu_reset() will reset mmu structs for all all open files to have zero users and their HW address space assignment. Then, when disabling hwperf, panfrost_mmu_as_put() will WARN that mmu->as_count is less than zero.
Fix this by introducing a perfcnt HW reset path. The choice was made to render perfcnt unusable after reset, so that a user might have to reprogram it with a full disable/enable sequence before requesting more perfcnt dumps. Signed-off-by: Adrián Larumbe <[email protected]> --- drivers/gpu/drm/panfrost/panfrost_device.c | 1 + drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 58 +++++++++++++++++++---------- drivers/gpu/drm/panfrost/panfrost_perfcnt.h | 1 + 3 files changed, 41 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c index 7fed22d555a5..2a4417bc4065 100644 --- a/drivers/gpu/drm/panfrost/panfrost_device.c +++ b/drivers/gpu/drm/panfrost/panfrost_device.c @@ -421,6 +421,7 @@ void panfrost_device_reset(struct panfrost_device *pfdev, bool enable_job_int) { panfrost_gpu_soft_reset(pfdev); + panfrost_perfcnt_reset(pfdev); panfrost_gpu_power_on(pfdev); panfrost_mmu_reset(pfdev); diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c index 7020c0192e18..d6a6fbe35578 100644 --- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c +++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c @@ -33,6 +33,7 @@ struct panfrost_perfcnt { struct panfrost_file_priv *user; struct mutex lock; struct completion dump_comp; + bool hw_reset_happened; }; void panfrost_perfcnt_clean_cache_done(struct panfrost_device *pfdev) @@ -166,6 +167,7 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev, /* The BO ref is retained by the mapping. */ drm_gem_object_put(&bo->base); + perfcnt->hw_reset_happened = false; perfcnt->user = user; return 0; @@ -183,6 +185,16 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev, return ret; } +static void panfrost_perfcnt_gpu_disable(struct panfrost_device *pfdev) +{ + gpu_write(pfdev, GPU_PERFCNT_CFG, + GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF)); + gpu_write(pfdev, GPU_PRFCNT_JM_EN, 0x0); + gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0x0); + gpu_write(pfdev, GPU_PRFCNT_MMU_L2_EN, 0x0); + gpu_write(pfdev, GPU_PRFCNT_TILER_EN, 0); +} + static int panfrost_perfcnt_disable_locked(struct panfrost_device *pfdev, struct drm_file *file_priv) { @@ -193,18 +205,14 @@ static int panfrost_perfcnt_disable_locked(struct panfrost_device *pfdev, if (user != perfcnt->user) return -EINVAL; - gpu_write(pfdev, GPU_PRFCNT_JM_EN, 0x0); - gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0x0); - gpu_write(pfdev, GPU_PRFCNT_MMU_L2_EN, 0x0); - gpu_write(pfdev, GPU_PRFCNT_TILER_EN, 0); - gpu_write(pfdev, GPU_PERFCNT_CFG, - GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF)); + panfrost_perfcnt_gpu_disable(pfdev); perfcnt->user = NULL; drm_gem_vunmap(&perfcnt->mapping->obj->base.base, &map); perfcnt->buf = NULL; panfrost_gem_close(&perfcnt->mapping->obj->base.base, file_priv); - panfrost_mmu_as_put(pfdev, perfcnt->mapping->mmu); + if (!perfcnt->hw_reset_happened) + panfrost_mmu_as_put(pfdev, perfcnt->mapping->mmu); panfrost_gem_mapping_put(perfcnt->mapping); perfcnt->mapping = NULL; pm_runtime_put_autosuspend(pfdev->base.dev); @@ -258,6 +266,15 @@ int panfrost_ioctl_perfcnt_dump(struct drm_device *dev, void *data, goto out; } + /* + * A HW reset when HWPerf was active mean user should go through + * a disable/enable sequence before requesting more frame dumps. + */ + if (perfcnt->hw_reset_happened) { + ret = -EAGAIN; + goto out; + } + ret = panfrost_perfcnt_dump_locked(pfdev); if (ret) goto out; @@ -327,12 +344,7 @@ int panfrost_perfcnt_init(struct panfrost_device *pfdev) perfcnt->bosize = size; /* Start with everything disabled. */ - gpu_write(pfdev, GPU_PERFCNT_CFG, - GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF)); - gpu_write(pfdev, GPU_PRFCNT_JM_EN, 0); - gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0); - gpu_write(pfdev, GPU_PRFCNT_MMU_L2_EN, 0); - gpu_write(pfdev, GPU_PRFCNT_TILER_EN, 0); + panfrost_perfcnt_gpu_disable(pfdev); init_completion(&perfcnt->dump_comp); mutex_init(&perfcnt->lock); @@ -344,10 +356,18 @@ int panfrost_perfcnt_init(struct panfrost_device *pfdev) void panfrost_perfcnt_fini(struct panfrost_device *pfdev) { /* Disable everything before leaving. */ - gpu_write(pfdev, GPU_PERFCNT_CFG, - GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF)); - gpu_write(pfdev, GPU_PRFCNT_JM_EN, 0); - gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0); - gpu_write(pfdev, GPU_PRFCNT_MMU_L2_EN, 0); - gpu_write(pfdev, GPU_PRFCNT_TILER_EN, 0); + panfrost_perfcnt_gpu_disable(pfdev); +} + +void panfrost_perfcnt_reset(struct panfrost_device *pfdev) +{ + struct panfrost_perfcnt *perfcnt = pfdev->perfcnt; + + mutex_lock(&perfcnt->lock); + if (perfcnt->user) { + panfrost_perfcnt_gpu_disable(pfdev); + panfrost_mmu_as_put(pfdev, perfcnt->mapping->mmu); + perfcnt->hw_reset_happened = true; + } + mutex_unlock(&perfcnt->lock); } diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.h b/drivers/gpu/drm/panfrost/panfrost_perfcnt.h index 8bbcf5f5fb33..8b9bc704b634 100644 --- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.h +++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.h @@ -14,5 +14,6 @@ int panfrost_ioctl_perfcnt_enable(struct drm_device *dev, void *data, struct drm_file *file_priv); int panfrost_ioctl_perfcnt_dump(struct drm_device *dev, void *data, struct drm_file *file_priv); +void panfrost_perfcnt_reset(struct panfrost_device *pfdev); #endif -- 2.53.0
