Commit 6a6b73f2 authored by Ben Skeggs's avatar Ben Skeggs
Browse files

drm/nouveau: add per-channel mutex, use to lock access to drm's channel 



This fixes a race condition between fbcon acceleration and TTM buffer
moves.  To reproduce:

- start X
- switch to vt and "while (true); do dmesg; done"
- switch to another vt and "sleep 2 && cat /path/to/debugfs/dri/0/evict_vram"
- switch back to vt running dmesg

We don't make use of this on any other channel yet, they're currently
protected by drm_global_mutex.  This will change in the near future.

Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent ceed5f30

drivers/gpu/drm/nouveau/nouveau_bo.c

+11 −4
Original line number Diff line number Diff line
@@ -683,17 +683,24 @@ nouveau_bo_move_m2mf(struct ttm_buffer_object *bo, int evict, bool intr, 
	int ret;



	chan = nvbo->channel;

	if (!chan || nvbo->no_vm)

	if (!chan || nvbo->no_vm) {

		chan = dev_priv->channel;

		mutex_lock(&chan->mutex);

	}



	if (dev_priv->card_type < NV_50)

		ret = nv04_bo_move_m2mf(chan, bo, &bo->mem, new_mem);

	else

		ret = nv50_bo_move_m2mf(chan, bo, &bo->mem, new_mem);

	if (ret)

		return ret;

	if (ret == 0) {

		ret = nouveau_bo_move_accel_cleanup(chan, nvbo, evict,

						    no_wait_reserve,

						    no_wait_gpu, new_mem);

	}



	return nouveau_bo_move_accel_cleanup(chan, nvbo, evict, no_wait_reserve, no_wait_gpu, new_mem);

	if (chan == dev_priv->channel)

		mutex_unlock(&chan->mutex);

	return ret;

}



static int

drivers/gpu/drm/nouveau/nouveau_channel.c

+1 −0
Original line number Diff line number Diff line
@@ -145,6 +145,7 @@ nouveau_channel_alloc(struct drm_device *dev, struct nouveau_channel **chan_ret, 
	chan->file_priv = file_priv;

	chan->vram_handle = vram_handle;

	chan->gart_handle = tt_handle;

	mutex_init(&chan->mutex);



	NV_INFO(dev, "Allocating FIFO number %d\n", channel);

drivers/gpu/drm/nouveau/nouveau_drv.h

+2 −0
Original line number Diff line number Diff line
@@ -166,6 +166,8 @@ struct nouveau_channel { 
	struct drm_device *dev;

	int id;



	struct mutex mutex;



	/* owner of this fifo */

	struct drm_file *file_priv;

	/* mapping of the fifo itself */

drivers/gpu/drm/nouveau/nouveau_fbcon.c

+14 −3
Original line number Diff line number Diff line
@@ -62,11 +62,13 @@ nouveau_fbcon_fillrect(struct fb_info *info, const struct fb_fillrect *rect) 


	ret = -ENODEV;

	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {

		mutex_lock(&dev_priv->channel->mutex);

		if (dev_priv->card_type < NV_50)

			ret = nv04_fbcon_fillrect(info, rect);

		else

		if (dev_priv->card_type < NV_C0)

			ret = nv50_fbcon_fillrect(info, rect);

		mutex_unlock(&dev_priv->channel->mutex);

	}



	if (ret == 0)
@@ -90,11 +92,13 @@ nouveau_fbcon_copyarea(struct fb_info *info, const struct fb_copyarea *image) 


	ret = -ENODEV;

	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {

		mutex_lock(&dev_priv->channel->mutex);

		if (dev_priv->card_type < NV_50)

			ret = nv04_fbcon_copyarea(info, image);

		else

		if (dev_priv->card_type < NV_C0)

			ret = nv50_fbcon_copyarea(info, image);

		mutex_unlock(&dev_priv->channel->mutex);

	}



	if (ret == 0)
@@ -118,11 +122,13 @@ nouveau_fbcon_imageblit(struct fb_info *info, const struct fb_image *image) 


	ret = -ENODEV;

	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {

		mutex_lock(&dev_priv->channel->mutex);

		if (dev_priv->card_type < NV_50)

			ret = nv04_fbcon_imageblit(info, image);

		else

		if (dev_priv->card_type < NV_C0)

			ret = nv50_fbcon_imageblit(info, image);

		mutex_unlock(&dev_priv->channel->mutex);

	}



	if (ret == 0)
@@ -142,12 +148,15 @@ nouveau_fbcon_sync(struct fb_info *info) 
	struct nouveau_channel *chan = dev_priv->channel;

	int ret, i;



	if (!chan || !chan->accel_done ||

	if (!chan || !chan->accel_done || in_interrupt() ||

	    info->state != FBINFO_STATE_RUNNING ||

	    info->flags & FBINFO_HWACCEL_DISABLED)

		return 0;



	if (RING_SPACE(chan, 4)) {

	mutex_lock(&chan->mutex);

	ret = RING_SPACE(chan, 4);

	if (ret) {

		mutex_unlock(&chan->mutex);

		nouveau_fbcon_gpu_lockup(info);

		return 0;

	}
@@ -158,6 +167,7 @@ nouveau_fbcon_sync(struct fb_info *info) 
	OUT_RING(chan, 0);

	nouveau_bo_wr32(chan->notifier_bo, chan->m2mf_ntfy + 3, 0xffffffff);

	FIRE_RING(chan);

	mutex_unlock(&chan->mutex);



	ret = -EBUSY;

	for (i = 0; i < 100000; i++) {
@@ -353,6 +363,8 @@ nouveau_fbcon_create(struct nouveau_fbdev *nfbdev, 
	info->pixmap.flags = FB_PIXMAP_SYSTEM;

	info->pixmap.scan_align = 1;



	mutex_unlock(&dev->struct_mutex);



	if (dev_priv->channel && !nouveau_nofbaccel) {

		ret = -ENODEV;

		if (dev_priv->card_type < NV_50)
@@ -373,7 +385,6 @@ nouveau_fbcon_create(struct nouveau_fbdev *nfbdev, 
						nouveau_fb->base.height,

						nvbo->bo.offset, nvbo);



	mutex_unlock(&dev->struct_mutex);

	vga_switcheroo_client_fb_set(dev->pdev, info);

	return 0;

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