drm: Remove locking for legacy ioctls and DRM_UNLOCKED

Modern DRM drivers acquire ioctl locks by themselves. Legacy ioctls
for user-space mode setting used to acquire drm_global_mutex. After
removing the ioctl entry points, also remove the locking code. The only
legacy ioctl without global locking was VBLANK_WAIT, which has been
removed as well. Hence remove the related DRM_UNLOCKED flag.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: David Airlie <airlied@gmail.com>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231122122449.11588-12-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
index 910cadf..129e2b9 100644 (file)
--- a/drivers/gpu/drm/drm_ioc32.c
+++ b/drivers/gpu/drm/drm_ioc32.c
@@ -273,7 +273,7 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd,
        req.request.type = req32.request.type;
        req.request.sequence = req32.request.sequence;
        req.request.signal = req32.request.signal;
-       err = drm_ioctl_kernel(file, drm_wait_vblank_ioctl, &req, DRM_UNLOCKED);
+       err = drm_ioctl_kernel(file, drm_wait_vblank_ioctl, &req, 0);
 
        req32.reply.type = req.reply.type;
        req32.reply.sequence = req.reply.sequence;

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index ebba34b..e368fc0 100644 (file)
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -596,7 +596,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
 
        DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
 
-       DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
+       DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, 0),
 
        DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 
@@ -729,7 +729,7 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
 {
        struct drm_file *file_priv = file->private_data;
        struct drm_device *dev = file_priv->minor->dev;
-       int retcode;
+       int ret;
 
        /* Update drm_file owner if fd was passed along. */
        drm_file_update_pid(file_priv);
@@ -737,20 +737,11 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
        if (drm_dev_is_unplugged(dev))
                return -ENODEV;
 
-       retcode = drm_ioctl_permit(flags, file_priv);
-       if (unlikely(retcode))
-               return retcode;
-
-       /* Enforce sane locking for modern driver ioctls. */
-       if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) ||
-           (flags & DRM_UNLOCKED))
-               retcode = func(dev, kdata, file_priv);
-       else {
-               mutex_lock(&drm_global_mutex);
-               retcode = func(dev, kdata, file_priv);
-               mutex_unlock(&drm_global_mutex);
-       }
-       return retcode;
+       ret = drm_ioctl_permit(flags, file_priv);
+       if (unlikely(ret))
+               return ret;
+
+       return func(dev, kdata, file_priv);
 }
 EXPORT_SYMBOL(drm_ioctl_kernel);
 

diff --git a/include/drm/drm_ioctl.h b/include/drm/drm_ioctl.h
index 6ed61c3..171760b 100644 (file)
--- a/include/drm/drm_ioctl.h
+++ b/include/drm/drm_ioctl.h
@@ -109,17 +109,6 @@ enum drm_ioctl_flags {
         * This is equivalent to callers with the SYSADMIN capability.
         */
        DRM_ROOT_ONLY           = BIT(2),
-       /**
-        * @DRM_UNLOCKED:
-        *
-        * Whether &drm_ioctl_desc.func should be called with the DRM BKL held
-        * or not. Enforced as the default for all modern drivers, hence there
-        * should never be a need to set this flag.
-        *
-        * Do not use anywhere else than for the VBLANK_WAIT IOCTL, which is the
-        * only legacy IOCTL which needs this.
-        */
-       DRM_UNLOCKED            = BIT(4),
        /**
         * @DRM_RENDER_ALLOW:
         *