drm/nouveau: protect channel create/destroy and irq handler with a spinlock

The nv50 pgraph handler (for example) could reenable pgraph fifo access
and that would be bad when pgraph context is being unloaded (we need the
guarantee a ctxprog isn't running).

Signed-off-by: Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_irq.c b/drivers/gpu/drm/nouveau/nouveau_irq.c
index 447f9f69d6b1..95220ddebb45 100644
--- a/drivers/gpu/drm/nouveau/nouveau_irq.c
+++ b/drivers/gpu/drm/nouveau/nouveau_irq.c
@@ -691,11 +691,14 @@ nouveau_irq_handler(DRM_IRQ_ARGS)
         struct drm_device *dev = (struct drm_device *)arg;
         struct drm_nouveau_private *dev_priv = dev->dev_private;
         uint32_t status, fbdev_flags = 0;
+        unsigned long flags;
 
         status = nv_rd32(dev, NV03_PMC_INTR_0);
         if (!status)
                 return IRQ_NONE;
 
+        spin_lock_irqsave(&dev_priv->context_switch_lock, flags);
+
         if (dev_priv->fbdev_info) {
                 fbdev_flags = dev_priv->fbdev_info->flags;
                 dev_priv->fbdev_info->flags |= FBINFO_HWACCEL_DISABLED;
@@ -733,5 +736,7 @@ nouveau_irq_handler(DRM_IRQ_ARGS)
         if (dev_priv->fbdev_info)
                 dev_priv->fbdev_info->flags = fbdev_flags;
 
+        spin_unlock_irqrestore(&dev_priv->context_switch_lock, flags);
+
         return IRQ_HANDLED;
 }