drm: Differentiate the lack of an interface from invalid parameter

If the ioctl is not supported on a particular piece of HW/driver
combination, report ENOTSUP (aka EOPNOTSUPP) so that it can be easily
distinguished from both the lack of the ioctl and from a regular invalid
parameter.

v2: Across all the kms ioctls we had a mixture of reporting EINVAL,
ENODEV and a few ENOTSUPP (most where EINVAL) for a failed
drm_core_check_feature(). Update everybody to report ENOTSUPP.

v3: ENOTSUPP is an internal errno! It's value (524) does not correspond
to a POSIX errno, the one we want is ENOTSUP. However,
uapi/asm-generic/errno.h doesn't include ENOTSUP but man errno says

	"ENOTSUP and EOPNOTSUPP have the same value on Linux,
	but according to POSIX.1 these error values should be
	distinct."

so use EOPNOTSUPP as its equivalent.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v2
Link: https://patchwork.freedesktop.org/patch/msgid/20180913192050.24812-1-chris@chris-wilson.co.uk

1 files changed, 16 insertions, 16 deletions

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index ba8cfe65c65b..7412acaf3cde 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -398,7 +398,7 @@ int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
 			      map->flags, &maplist);
@@ -444,7 +444,7 @@ int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	idx = map->offset;
 	if (idx < 0)
@@ -596,7 +596,7 @@ int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	mutex_lock(&dev->struct_mutex);
 	list_for_each_entry(r_list, &dev->maplist, head) {
@@ -860,7 +860,7 @@ int drm_legacy_addbufs_pci(struct drm_device *dev,
 	struct drm_buf **temp_buflist;
 
 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1064,7 +1064,7 @@ static int drm_legacy_addbufs_sg(struct drm_device *dev,
 	struct drm_buf **temp_buflist;
 
 	if (!drm_core_check_feature(dev, DRIVER_SG))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1221,10 +1221,10 @@ int drm_legacy_addbufs(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 #if IS_ENABLED(CONFIG_AGP)
 	if (request->flags & _DRM_AGP_BUFFER)
@@ -1267,10 +1267,10 @@ int __drm_legacy_infobufs(struct drm_device *dev,
 	int count;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1352,10 +1352,10 @@ int drm_legacy_markbufs(struct drm_device *dev, void *data,
 	struct drm_buf_entry *entry;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1400,10 +1400,10 @@ int drm_legacy_freebufs(struct drm_device *dev, void *data,
 	struct drm_buf *buf;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1455,10 +1455,10 @@ int __drm_legacy_mapbufs(struct drm_device *dev, void *data, int *p,
 	int i;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1545,7 +1545,7 @@ int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
 		  struct drm_file *file_priv)
 {
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (dev->driver->dma_ioctl)
 		return dev->driver->dma_ioctl(dev, data, file_priv);