drm/nouveau: Refactor context destruction to avoid a lock ordering issue.
The destroy_context() engine hooks call gpuobj management functions to
release the channel resources, these functions use HARDIRQ-unsafe locks
whereas destroy_context() is called with the HARDIRQ-safe
context_switch_lock held, that's a lock ordering violation.
Push the engine-specific channel destruction logic into destroy_context()
and let the hardware-specific code lock and unlock when it's actually
needed. Change the engine destruction order to avoid a race in the small
gap between pgraph and pfifo context uninitialization.
Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_channel.c b/drivers/gpu/drm/nouveau/nouveau_channel.c
index 0e2414b..9a051fa 100644
--- a/drivers/gpu/drm/nouveau/nouveau_channel.c
+++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
@@ -313,32 +313,20 @@
/* boot it off the hardware */
pfifo->reassign(dev, false);
- /* We want to give pgraph a chance to idle and get rid of all potential
- * errors. We need to do this before the lock, otherwise the irq handler
- * is unable to process them.
+ /* We want to give pgraph a chance to idle and get rid of all
+ * potential errors. We need to do this without the context
+ * switch lock held, otherwise the irq handler is unable to
+ * process them.
*/
if (pgraph->channel(dev) == chan)
nouveau_wait_for_idle(dev);
- spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
-
- pgraph->fifo_access(dev, false);
- if (pgraph->channel(dev) == chan)
- pgraph->unload_context(dev);
- pgraph->destroy_context(chan);
- pgraph->fifo_access(dev, true);
-
- if (pfifo->channel_id(dev) == chan->id) {
- pfifo->disable(dev);
- pfifo->unload_context(dev);
- pfifo->enable(dev);
- }
+ /* destroy the engine specific contexts */
pfifo->destroy_context(chan);
+ pgraph->destroy_context(chan);
pfifo->reassign(dev, true);
- spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
-
/* aside from its resources, the channel should now be dead,
* remove it from the channel list
*/
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 699d546..198dabe 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -998,14 +998,12 @@
extern int nv10_fifo_init(struct drm_device *);
extern int nv10_fifo_channel_id(struct drm_device *);
extern int nv10_fifo_create_context(struct nouveau_channel *);
-extern void nv10_fifo_destroy_context(struct nouveau_channel *);
extern int nv10_fifo_load_context(struct nouveau_channel *);
extern int nv10_fifo_unload_context(struct drm_device *);
/* nv40_fifo.c */
extern int nv40_fifo_init(struct drm_device *);
extern int nv40_fifo_create_context(struct nouveau_channel *);
-extern void nv40_fifo_destroy_context(struct nouveau_channel *);
extern int nv40_fifo_load_context(struct nouveau_channel *);
extern int nv40_fifo_unload_context(struct drm_device *);
diff --git a/drivers/gpu/drm/nouveau/nouveau_state.c b/drivers/gpu/drm/nouveau/nouveau_state.c
index 513c106..1a4ba6c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_state.c
+++ b/drivers/gpu/drm/nouveau/nouveau_state.c
@@ -137,7 +137,7 @@
engine->fifo.cache_pull = nv04_fifo_cache_pull;
engine->fifo.channel_id = nv10_fifo_channel_id;
engine->fifo.create_context = nv10_fifo_create_context;
- engine->fifo.destroy_context = nv10_fifo_destroy_context;
+ engine->fifo.destroy_context = nv04_fifo_destroy_context;
engine->fifo.load_context = nv10_fifo_load_context;
engine->fifo.unload_context = nv10_fifo_unload_context;
engine->display.early_init = nv04_display_early_init;
@@ -191,7 +191,7 @@
engine->fifo.cache_pull = nv04_fifo_cache_pull;
engine->fifo.channel_id = nv10_fifo_channel_id;
engine->fifo.create_context = nv10_fifo_create_context;
- engine->fifo.destroy_context = nv10_fifo_destroy_context;
+ engine->fifo.destroy_context = nv04_fifo_destroy_context;
engine->fifo.load_context = nv10_fifo_load_context;
engine->fifo.unload_context = nv10_fifo_unload_context;
engine->display.early_init = nv04_display_early_init;
@@ -245,7 +245,7 @@
engine->fifo.cache_pull = nv04_fifo_cache_pull;
engine->fifo.channel_id = nv10_fifo_channel_id;
engine->fifo.create_context = nv10_fifo_create_context;
- engine->fifo.destroy_context = nv10_fifo_destroy_context;
+ engine->fifo.destroy_context = nv04_fifo_destroy_context;
engine->fifo.load_context = nv10_fifo_load_context;
engine->fifo.unload_context = nv10_fifo_unload_context;
engine->display.early_init = nv04_display_early_init;
@@ -302,7 +302,7 @@
engine->fifo.cache_pull = nv04_fifo_cache_pull;
engine->fifo.channel_id = nv10_fifo_channel_id;
engine->fifo.create_context = nv40_fifo_create_context;
- engine->fifo.destroy_context = nv40_fifo_destroy_context;
+ engine->fifo.destroy_context = nv04_fifo_destroy_context;
engine->fifo.load_context = nv40_fifo_load_context;
engine->fifo.unload_context = nv40_fifo_unload_context;
engine->display.early_init = nv04_display_early_init;
diff --git a/drivers/gpu/drm/nouveau/nv04_fifo.c b/drivers/gpu/drm/nouveau/nv04_fifo.c
index 25c439d..4c0d3a8 100644
--- a/drivers/gpu/drm/nouveau/nv04_fifo.c
+++ b/drivers/gpu/drm/nouveau/nv04_fifo.c
@@ -151,10 +151,27 @@
nv04_fifo_destroy_context(struct nouveau_channel *chan)
{
struct drm_device *dev = chan->dev;
+ struct drm_nouveau_private *dev_priv = dev->dev_private;
+ struct nouveau_fifo_engine *pfifo = &dev_priv->engine.fifo;
+ unsigned long flags;
- nv_wr32(dev, NV04_PFIFO_MODE,
- nv_rd32(dev, NV04_PFIFO_MODE) & ~(1 << chan->id));
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+ pfifo->reassign(dev, false);
+ /* Unload the context if it's the currently active one */
+ if (pfifo->channel_id(dev) == chan->id) {
+ pfifo->disable(dev);
+ pfifo->unload_context(dev);
+ pfifo->enable(dev);
+ }
+
+ /* Keep it from being rescheduled */
+ nv_mask(dev, NV04_PFIFO_MODE, 1 << chan->id, 0);
+
+ pfifo->reassign(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
+
+ /* Free the channel resources */
nouveau_gpuobj_ref(NULL, &chan->ramfc);
}
diff --git a/drivers/gpu/drm/nouveau/nv04_graph.c b/drivers/gpu/drm/nouveau/nv04_graph.c
index 98b9525..1e2ad39 100644
--- a/drivers/gpu/drm/nouveau/nv04_graph.c
+++ b/drivers/gpu/drm/nouveau/nv04_graph.c
@@ -412,10 +412,25 @@
void nv04_graph_destroy_context(struct nouveau_channel *chan)
{
+ struct drm_device *dev = chan->dev;
+ struct drm_nouveau_private *dev_priv = dev->dev_private;
+ struct nouveau_pgraph_engine *pgraph = &dev_priv->engine.graph;
struct graph_state *pgraph_ctx = chan->pgraph_ctx;
+ unsigned long flags;
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+ pgraph->fifo_access(dev, false);
+
+ /* Unload the context if it's the currently active one */
+ if (pgraph->channel(dev) == chan)
+ pgraph->unload_context(dev);
+
+ /* Free the context resources */
kfree(pgraph_ctx);
chan->pgraph_ctx = NULL;
+
+ pgraph->fifo_access(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
}
int nv04_graph_load_context(struct nouveau_channel *chan)
diff --git a/drivers/gpu/drm/nouveau/nv10_fifo.c b/drivers/gpu/drm/nouveau/nv10_fifo.c
index 39328fc..912556f 100644
--- a/drivers/gpu/drm/nouveau/nv10_fifo.c
+++ b/drivers/gpu/drm/nouveau/nv10_fifo.c
@@ -73,17 +73,6 @@
return 0;
}
-void
-nv10_fifo_destroy_context(struct nouveau_channel *chan)
-{
- struct drm_device *dev = chan->dev;
-
- nv_wr32(dev, NV04_PFIFO_MODE,
- nv_rd32(dev, NV04_PFIFO_MODE) & ~(1 << chan->id));
-
- nouveau_gpuobj_ref(NULL, &chan->ramfc);
-}
-
static void
nv10_fifo_do_load_context(struct drm_device *dev, int chid)
{
diff --git a/drivers/gpu/drm/nouveau/nv10_graph.c b/drivers/gpu/drm/nouveau/nv10_graph.c
index cd931b5..e3a87a6 100644
--- a/drivers/gpu/drm/nouveau/nv10_graph.c
+++ b/drivers/gpu/drm/nouveau/nv10_graph.c
@@ -875,10 +875,25 @@
void nv10_graph_destroy_context(struct nouveau_channel *chan)
{
+ struct drm_device *dev = chan->dev;
+ struct drm_nouveau_private *dev_priv = dev->dev_private;
+ struct nouveau_pgraph_engine *pgraph = &dev_priv->engine.graph;
struct graph_state *pgraph_ctx = chan->pgraph_ctx;
+ unsigned long flags;
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+ pgraph->fifo_access(dev, false);
+
+ /* Unload the context if it's the currently active one */
+ if (pgraph->channel(dev) == chan)
+ pgraph->unload_context(dev);
+
+ /* Free the context resources */
kfree(pgraph_ctx);
chan->pgraph_ctx = NULL;
+
+ pgraph->fifo_access(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
}
void
diff --git a/drivers/gpu/drm/nouveau/nv20_graph.c b/drivers/gpu/drm/nouveau/nv20_graph.c
index 12ab9cd..8a04020 100644
--- a/drivers/gpu/drm/nouveau/nv20_graph.c
+++ b/drivers/gpu/drm/nouveau/nv20_graph.c
@@ -425,9 +425,21 @@
struct drm_device *dev = chan->dev;
struct drm_nouveau_private *dev_priv = dev->dev_private;
struct nouveau_pgraph_engine *pgraph = &dev_priv->engine.graph;
+ unsigned long flags;
- nouveau_gpuobj_ref(NULL, &chan->ramin_grctx);
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+ pgraph->fifo_access(dev, false);
+
+ /* Unload the context if it's the currently active one */
+ if (pgraph->channel(dev) == chan)
+ pgraph->unload_context(dev);
+
+ pgraph->fifo_access(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
+
+ /* Free the context resources */
nv_wo32(pgraph->ctx_table, chan->id * 4, 0);
+ nouveau_gpuobj_ref(NULL, &chan->ramin_grctx);
}
int
diff --git a/drivers/gpu/drm/nouveau/nv40_fifo.c b/drivers/gpu/drm/nouveau/nv40_fifo.c
index 3c7be3d..311ac9e 100644
--- a/drivers/gpu/drm/nouveau/nv40_fifo.c
+++ b/drivers/gpu/drm/nouveau/nv40_fifo.c
@@ -70,17 +70,6 @@
return 0;
}
-void
-nv40_fifo_destroy_context(struct nouveau_channel *chan)
-{
- struct drm_device *dev = chan->dev;
-
- nv_wr32(dev, NV04_PFIFO_MODE,
- nv_rd32(dev, NV04_PFIFO_MODE) & ~(1 << chan->id));
-
- nouveau_gpuobj_ref(NULL, &chan->ramfc);
-}
-
static void
nv40_fifo_do_load_context(struct drm_device *dev, int chid)
{
diff --git a/drivers/gpu/drm/nouveau/nv40_graph.c b/drivers/gpu/drm/nouveau/nv40_graph.c
index e0b41a2..70d97cd 100644
--- a/drivers/gpu/drm/nouveau/nv40_graph.c
+++ b/drivers/gpu/drm/nouveau/nv40_graph.c
@@ -79,6 +79,22 @@
void
nv40_graph_destroy_context(struct nouveau_channel *chan)
{
+ struct drm_device *dev = chan->dev;
+ struct drm_nouveau_private *dev_priv = dev->dev_private;
+ struct nouveau_pgraph_engine *pgraph = &dev_priv->engine.graph;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+ pgraph->fifo_access(dev, false);
+
+ /* Unload the context if it's the currently active one */
+ if (pgraph->channel(dev) == chan)
+ pgraph->unload_context(dev);
+
+ pgraph->fifo_access(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
+
+ /* Free the context resources */
nouveau_gpuobj_ref(NULL, &chan->ramin_grctx);
}
diff --git a/drivers/gpu/drm/nouveau/nv50_fifo.c b/drivers/gpu/drm/nouveau/nv50_fifo.c
index 815960f..d3295aa 100644
--- a/drivers/gpu/drm/nouveau/nv50_fifo.c
+++ b/drivers/gpu/drm/nouveau/nv50_fifo.c
@@ -292,10 +292,23 @@
nv50_fifo_destroy_context(struct nouveau_channel *chan)
{
struct drm_device *dev = chan->dev;
+ struct drm_nouveau_private *dev_priv = dev->dev_private;
+ struct nouveau_fifo_engine *pfifo = &dev_priv->engine.fifo;
struct nouveau_gpuobj *ramfc = NULL;
+ unsigned long flags;
NV_DEBUG(dev, "ch%d\n", chan->id);
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+ pfifo->reassign(dev, false);
+
+ /* Unload the context if it's the currently active one */
+ if (pfifo->channel_id(dev) == chan->id) {
+ pfifo->disable(dev);
+ pfifo->unload_context(dev);
+ pfifo->enable(dev);
+ }
+
/* This will ensure the channel is seen as disabled. */
nouveau_gpuobj_ref(chan->ramfc, &ramfc);
nouveau_gpuobj_ref(NULL, &chan->ramfc);
@@ -306,6 +319,10 @@
nv50_fifo_channel_disable(dev, 127);
nv50_fifo_playlist_update(dev);
+ pfifo->reassign(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
+
+ /* Free the channel resources */
nouveau_gpuobj_ref(NULL, &ramfc);
nouveau_gpuobj_ref(NULL, &chan->cache);
}
diff --git a/drivers/gpu/drm/nouveau/nv50_graph.c b/drivers/gpu/drm/nouveau/nv50_graph.c
index 24a3f84..dcc9175 100644
--- a/drivers/gpu/drm/nouveau/nv50_graph.c
+++ b/drivers/gpu/drm/nouveau/nv50_graph.c
@@ -242,17 +242,28 @@
{
struct drm_device *dev = chan->dev;
struct drm_nouveau_private *dev_priv = dev->dev_private;
+ struct nouveau_pgraph_engine *pgraph = &dev_priv->engine.graph;
int i, hdr = (dev_priv->chipset == 0x50) ? 0x200 : 0x20;
+ unsigned long flags;
NV_DEBUG(dev, "ch%d\n", chan->id);
if (!chan->ramin)
return;
+ spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+ pgraph->fifo_access(dev, false);
+
+ if (pgraph->channel(dev) == chan)
+ pgraph->unload_context(dev);
+
for (i = hdr; i < hdr + 24; i += 4)
nv_wo32(chan->ramin, i, 0);
dev_priv->engine.instmem.flush(dev);
+ pgraph->fifo_access(dev, true);
+ spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
+
nouveau_gpuobj_ref(NULL, &chan->ramin_grctx);
}
