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Commit cb74f6ee authored by Eric Anholt's avatar Eric Anholt
Browse files

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: default avatarEric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190220210343.28157-6-eric@anholt.net


Reviewed-by: default avatarPaul Kocialkowski <paul.kocialkowski@bootlin.com>
parent 13f0ec34

drivers/gpu/drm/vc4/vc4_drv.c

+9 −12
Original line number Diff line number Diff line
@@ -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:

drivers/gpu/drm/vc4/vc4_drv.h

+2 −0
Original line number Diff line number Diff line
@@ -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

drivers/gpu/drm/vc4/vc4_gem.c

+5 −16
Original line number Diff line number Diff line
@@ -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--;

	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);

drivers/gpu/drm/vc4/vc4_v3d.c

+33 −0
Original line number Diff line number Diff line
@@ -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);