drm/nouveau: disallow fbcon accel if running in interrupt context

A future commit will add locking to the DRM's channel, and there's numerous
problems that come up if we allow printk from an interrupt context to be
accelerated.  It seems saner to just disallow it completely.

As a nice side-effect, all the "to accel or not to accel" logic gets moved
out of the chipset-specific code.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 101 insertions, 36 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index 02a4d1fd4845..22e83adcc930 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -49,6 +49,90 @@
 #include "nouveau_fbcon.h"
 #include "nouveau_dma.h"
 
+static void
+nouveau_fbcon_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+	struct nouveau_fbdev *nfbdev = info->par;
+	struct drm_device *dev = nfbdev->dev;
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	int ret;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return;
+
+	ret = -ENODEV;
+	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {
+		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);
+	}
+
+	if (ret == 0)
+		return;
+
+	if (ret != -ENODEV)
+		nouveau_fbcon_gpu_lockup(info);
+	cfb_fillrect(info, rect);
+}
+
+static void
+nouveau_fbcon_copyarea(struct fb_info *info, const struct fb_copyarea *image)
+{
+	struct nouveau_fbdev *nfbdev = info->par;
+	struct drm_device *dev = nfbdev->dev;
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	int ret;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return;
+
+	ret = -ENODEV;
+	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {
+		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);
+	}
+
+	if (ret == 0)
+		return;
+
+	if (ret != -ENODEV)
+		nouveau_fbcon_gpu_lockup(info);
+	cfb_copyarea(info, image);
+}
+
+static void
+nouveau_fbcon_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+	struct nouveau_fbdev *nfbdev = info->par;
+	struct drm_device *dev = nfbdev->dev;
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	int ret;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return;
+
+	ret = -ENODEV;
+	if (!in_interrupt() && !(info->flags & FBINFO_HWACCEL_DISABLED)) {
+		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);
+	}
+
+	if (ret == 0)
+		return;
+
+	if (ret != -ENODEV)
+		nouveau_fbcon_gpu_lockup(info);
+	cfb_imageblit(info, image);
+}
+
 static int
 nouveau_fbcon_sync(struct fb_info *info)
 {
@@ -97,24 +181,9 @@ static struct fb_ops nouveau_fbcon_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = drm_fb_helper_check_var,
 	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = cfb_fillrect,
-	.fb_copyarea = cfb_copyarea,
-	.fb_imageblit = cfb_imageblit,
-	.fb_sync = nouveau_fbcon_sync,
-	.fb_pan_display = drm_fb_helper_pan_display,
-	.fb_blank = drm_fb_helper_blank,
-	.fb_setcmap = drm_fb_helper_setcmap,
-	.fb_debug_enter = drm_fb_helper_debug_enter,
-	.fb_debug_leave = drm_fb_helper_debug_leave,
-};
-
-static struct fb_ops nv04_fbcon_ops = {
-	.owner = THIS_MODULE,
-	.fb_check_var = drm_fb_helper_check_var,
-	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = nv04_fbcon_fillrect,
-	.fb_copyarea = nv04_fbcon_copyarea,
-	.fb_imageblit = nv04_fbcon_imageblit,
+	.fb_fillrect = nouveau_fbcon_fillrect,
+	.fb_copyarea = nouveau_fbcon_copyarea,
+	.fb_imageblit = nouveau_fbcon_imageblit,
 	.fb_sync = nouveau_fbcon_sync,
 	.fb_pan_display = drm_fb_helper_pan_display,
 	.fb_blank = drm_fb_helper_blank,
@@ -123,14 +192,13 @@ static struct fb_ops nv04_fbcon_ops = {
 	.fb_debug_leave = drm_fb_helper_debug_leave,
 };
 
-static struct fb_ops nv50_fbcon_ops = {
+static struct fb_ops nouveau_fbcon_sw_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = drm_fb_helper_check_var,
 	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = nv50_fbcon_fillrect,
-	.fb_copyarea = nv50_fbcon_copyarea,
-	.fb_imageblit = nv50_fbcon_imageblit,
-	.fb_sync = nouveau_fbcon_sync,
+	.fb_fillrect = cfb_fillrect,
+	.fb_copyarea = cfb_copyarea,
+	.fb_imageblit = cfb_imageblit,
 	.fb_pan_display = drm_fb_helper_pan_display,
 	.fb_blank = drm_fb_helper_blank,
 	.fb_setcmap = drm_fb_helper_setcmap,
@@ -257,7 +325,7 @@ nouveau_fbcon_create(struct nouveau_fbdev *nfbdev,
 			      FBINFO_HWACCEL_FILLRECT |
 			      FBINFO_HWACCEL_IMAGEBLIT;
 	info->flags |= FBINFO_CAN_FORCE_OUTPUT;
-	info->fbops = &nouveau_fbcon_ops;
+	info->fbops = &nouveau_fbcon_sw_ops;
 	info->fix.smem_start = dev->mode_config.fb_base + nvbo->bo.offset -
 			       dev_priv->vm_vram_base;
 	info->fix.smem_len = size;
@@ -286,18 +354,15 @@ nouveau_fbcon_create(struct nouveau_fbdev *nfbdev,
 	info->pixmap.scan_align = 1;
 
 	if (dev_priv->channel && !nouveau_nofbaccel) {
-		switch (dev_priv->card_type) {
-		case NV_C0:
-			break;
-		case NV_50:
-			nv50_fbcon_accel_init(info);
-			info->fbops = &nv50_fbcon_ops;
-			break;
-		default:
-			nv04_fbcon_accel_init(info);
-			info->fbops = &nv04_fbcon_ops;
-			break;
-		};
+		ret = -ENODEV;
+		if (dev_priv->card_type < NV_50)
+			ret = nv04_fbcon_accel_init(info);
+		else
+		if (dev_priv->card_type < NV_C0)
+			ret = nv50_fbcon_accel_init(info);
+
+		if (ret == 0)
+			info->fbops = &nouveau_fbcon_ops;
 	}
 
 	nouveau_fbcon_zfill(dev, nfbdev);