From cb74f6ee8e3a00e85d53697d5d84ec21d416e5ef Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Wed, 20 Feb 2019 13:03:42 -0800 Subject: [PATCH] drm/vc4: Add helpers for pm get/put. This makes sure the vc4_reset doesn't hit an obscure race with the GET_PARAM ioctl, fixes a decrement outside of the lock, and prevents future code from making mistakes with the weird return value of pm_runtime_get_sync(). Signed-off-by: Eric Anholt Link: https://patchwork.freedesktop.org/patch/msgid/20190220210343.28157-6-eric@anholt.net Reviewed-by: Paul Kocialkowski --- drivers/gpu/drm/vc4/vc4_drv.c | 21 +++++++++------------ drivers/gpu/drm/vc4/vc4_drv.h | 2 ++ drivers/gpu/drm/vc4/vc4_gem.c | 21 +++++---------------- drivers/gpu/drm/vc4/vc4_v3d.c | 33 +++++++++++++++++++++++++++++++++ 4 files changed, 49 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index 4daf44fd4548..f2d0fb3aa729 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -74,28 +74,25 @@ static int vc4_get_param_ioctl(struct drm_device *dev, void *data, switch (args->param) { case DRM_VC4_PARAM_V3D_IDENT0: - ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev); - if (ret < 0) + ret = vc4_v3d_pm_get(vc4); + if (ret) return ret; args->value = V3D_READ(V3D_IDENT0); - pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev); - pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev); + vc4_v3d_pm_put(vc4); break; case DRM_VC4_PARAM_V3D_IDENT1: - ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev); - if (ret < 0) + ret = vc4_v3d_pm_get(vc4); + if (ret) return ret; args->value = V3D_READ(V3D_IDENT1); - pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev); - pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev); + vc4_v3d_pm_put(vc4); break; case DRM_VC4_PARAM_V3D_IDENT2: - ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev); - if (ret < 0) + ret = vc4_v3d_pm_get(vc4); + if (ret) return ret; args->value = V3D_READ(V3D_IDENT2); - pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev); - pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev); + vc4_v3d_pm_put(vc4); break; case DRM_VC4_PARAM_SUPPORTS_BRANCHES: case DRM_VC4_PARAM_SUPPORTS_ETC1: diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h index 5156ede0f7b7..f6c9de75d465 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.h +++ b/drivers/gpu/drm/vc4/vc4_drv.h @@ -815,6 +815,8 @@ extern struct platform_driver vc4_v3d_driver; int vc4_v3d_debugfs_ident(struct seq_file *m, void *unused); int vc4_v3d_debugfs_regs(struct seq_file *m, void *unused); int vc4_v3d_get_bin_slot(struct vc4_dev *vc4); +int vc4_v3d_pm_get(struct vc4_dev *vc4); +void vc4_v3d_pm_put(struct vc4_dev *vc4); /* vc4_validate.c */ int diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c index 5ee5bf7fedf7..5e9496d477bf 100644 --- a/drivers/gpu/drm/vc4/vc4_gem.c +++ b/drivers/gpu/drm/vc4/vc4_gem.c @@ -964,12 +964,7 @@ vc4_complete_exec(struct drm_device *dev, struct vc4_exec_info *exec) /* Release the reference we had on the perf monitor. */ vc4_perfmon_put(exec->perfmon); - mutex_lock(&vc4->power_lock); - if (--vc4->power_refcount == 0) { - pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev); - pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev); - } - mutex_unlock(&vc4->power_lock); + vc4_v3d_pm_put(vc4); kfree(exec); } @@ -1143,17 +1138,11 @@ vc4_submit_cl_ioctl(struct drm_device *dev, void *data, return -ENOMEM; } - mutex_lock(&vc4->power_lock); - if (vc4->power_refcount++ == 0) { - ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev); - if (ret < 0) { - mutex_unlock(&vc4->power_lock); - vc4->power_refcount--; - kfree(exec); - return ret; - } + ret = vc4_v3d_pm_get(vc4); + if (ret) { + kfree(exec); + return ret; } - mutex_unlock(&vc4->power_lock); exec->args = args; INIT_LIST_HEAD(&exec->unref_list); diff --git a/drivers/gpu/drm/vc4/vc4_v3d.c b/drivers/gpu/drm/vc4/vc4_v3d.c index e1e728e95562..b2b974f20e23 100644 --- a/drivers/gpu/drm/vc4/vc4_v3d.c +++ b/drivers/gpu/drm/vc4/vc4_v3d.c @@ -138,6 +138,39 @@ int vc4_v3d_debugfs_ident(struct seq_file *m, void *unused) } #endif /* CONFIG_DEBUG_FS */ +/** + * Wraps pm_runtime_get_sync() in a refcount, so that we can reliably + * get the pm_runtime refcount to 0 in vc4_reset(). + */ +int +vc4_v3d_pm_get(struct vc4_dev *vc4) +{ + mutex_lock(&vc4->power_lock); + if (vc4->power_refcount++ == 0) { + int ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev); + + if (ret < 0) { + vc4->power_refcount--; + mutex_unlock(&vc4->power_lock); + return ret; + } + } + mutex_unlock(&vc4->power_lock); + + return 0; +} + +void +vc4_v3d_pm_put(struct vc4_dev *vc4) +{ + mutex_lock(&vc4->power_lock); + if (--vc4->power_refcount == 0) { + pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev); + pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev); + } + mutex_unlock(&vc4->power_lock); +} + static void vc4_v3d_init_hw(struct drm_device *dev) { struct vc4_dev *vc4 = to_vc4_dev(dev); -- 2.30.2