drm/nouveau: split ramin_lock into two locks, one hardirq safe

Fixes a possible lock ordering reversal between context_switch_lock
and ramin_lock.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_object.c b/drivers/gpu/drm/nouveau/nouveau_object.c
index 4f00c87ed86..67a16e01ffa 100644
--- a/drivers/gpu/drm/nouveau/nouveau_object.c
+++ b/drivers/gpu/drm/nouveau/nouveau_object.c
@@ -1039,19 +1039,20 @@ nv_ro32(struct nouveau_gpuobj *gpuobj, u32 offset)
 {
 	struct drm_nouveau_private *dev_priv = gpuobj->dev->dev_private;
 	struct drm_device *dev = gpuobj->dev;
+	unsigned long flags;
 
 	if (gpuobj->pinst == ~0 || !dev_priv->ramin_available) {
 		u64  ptr = gpuobj->vinst + offset;
 		u32 base = ptr >> 16;
 		u32  val;
 
-		spin_lock(&dev_priv->ramin_lock);
+		spin_lock_irqsave(&dev_priv->vm_lock, flags);
 		if (dev_priv->ramin_base != base) {
 			dev_priv->ramin_base = base;
 			nv_wr32(dev, 0x001700, dev_priv->ramin_base);
 		}
 		val = nv_rd32(dev, 0x700000 + (ptr & 0xffff));
-		spin_unlock(&dev_priv->ramin_lock);
+		spin_unlock_irqrestore(&dev_priv->vm_lock, flags);
 		return val;
 	}
 
@@ -1063,18 +1064,19 @@ nv_wo32(struct nouveau_gpuobj *gpuobj, u32 offset, u32 val)
 {
 	struct drm_nouveau_private *dev_priv = gpuobj->dev->dev_private;
 	struct drm_device *dev = gpuobj->dev;
+	unsigned long flags;
 
 	if (gpuobj->pinst == ~0 || !dev_priv->ramin_available) {
 		u64  ptr = gpuobj->vinst + offset;
 		u32 base = ptr >> 16;
 
-		spin_lock(&dev_priv->ramin_lock);
+		spin_lock_irqsave(&dev_priv->vm_lock, flags);
 		if (dev_priv->ramin_base != base) {
 			dev_priv->ramin_base = base;
 			nv_wr32(dev, 0x001700, dev_priv->ramin_base);
 		}
 		nv_wr32(dev, 0x700000 + (ptr & 0xffff), val);
-		spin_unlock(&dev_priv->ramin_lock);
+		spin_unlock_irqrestore(&dev_priv->vm_lock, flags);
 		return;
 	}