This patch introduces a new kind of drm device node: the render node. A render node exposes a safe subset of the legacy drm device ioctls and can only be used for rendering. The legacy node supports modesetting, DRI1 and global buffer sharing, while the render node only supports rendering and limited buffer sharing. A render node can either export a buffer using the gem flink mechanism, or it can import and export buffers using the prime fd passing mechanism.
A render node is not associated with any drm master and does not require the legacy authentication step. Render nodes can be used without a master, potentially in headless setups such as video-transcoding or GPGPU work.
Signed-off-by: Kristian Høgsberg krh@bitplanet.net --- drivers/gpu/drm/drm_drv.c | 13 +++++++------ drivers/gpu/drm/drm_fops.c | 9 ++++++--- drivers/gpu/drm/drm_pci.c | 9 +++++++++ include/drm/drmP.h | 3 +++ 4 files changed, 25 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 9238de4..2876e17 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -131,14 +131,14 @@ static struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
- DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED), - DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED | DRM_RENDER_ALLOW), + DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED | DRM_RENDER_ALLOW), DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
- DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED), - DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW), + DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED), @@ -427,9 +427,10 @@ long drm_ioctl(struct file *filp, DRM_DEBUG("no function\n"); retcode = -EINVAL; } else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) || - ((ioctl->flags & DRM_AUTH) && !file_priv->authenticated) || + ((ioctl->flags & DRM_AUTH) && (file_priv->minor->type != DRM_MINOR_RENDER) && !file_priv->authenticated) || ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) || - (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL))) { + (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL)) || + (!(ioctl->flags & DRM_RENDER_ALLOW) && (file_priv->minor->type == DRM_MINOR_RENDER))) { retcode = -EACCES; } else { if (cmd & (IOC_IN | IOC_OUT)) { diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 5062eec..bee4244 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -279,7 +279,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
/* if there is no current master make this fd it */ mutex_lock(&dev->struct_mutex); - if (!priv->minor->master) { + if (!priv->minor->master && priv->minor->type != DRM_MINOR_RENDER) { /* create a new master */ priv->minor->master = drm_master_create(priv->minor); if (!priv->minor->master) { @@ -318,10 +318,12 @@ static int drm_open_helper(struct inode *inode, struct file *filp, } } mutex_unlock(&dev->struct_mutex); - } else { + } else if (priv->minor->type != DRM_MINOR_RENDER) { /* get a reference to the master */ priv->master = drm_master_get(priv->minor->master); mutex_unlock(&dev->struct_mutex); + } else { + mutex_unlock(&dev->struct_mutex); }
mutex_lock(&dev->struct_mutex); @@ -513,7 +515,8 @@ int drm_release(struct inode *inode, struct file *filp) iput(container_of(dev->dev_mapping, struct inode, i_data));
/* drop the reference held my the file priv */ - drm_master_put(&file_priv->master); + if (file_priv->master) + drm_master_put(&file_priv->master); file_priv->is_master = 0; list_del(&file_priv->lhead); mutex_unlock(&dev->struct_mutex); diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c index 5320364..ff53f9c 100644 --- a/drivers/gpu/drm/drm_pci.c +++ b/drivers/gpu/drm/drm_pci.c @@ -348,6 +348,12 @@ int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent, goto err_g2; }
+ if (drm_core_check_feature(dev, DRIVER_RENDER)) { + ret = drm_get_minor(dev, &dev->render, DRM_MINOR_RENDER); + if (ret) + goto err_g21; + } + if ((ret = drm_get_minor(dev, &dev->primary, DRM_MINOR_LEGACY))) goto err_g3;
@@ -377,6 +383,9 @@ int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent, err_g4: drm_put_minor(&dev->primary); err_g3: + if (drm_core_check_feature(dev, DRIVER_RENDER)) + drm_put_minor(&dev->render); +err_g21: if (drm_core_check_feature(dev, DRIVER_MODESET)) drm_put_minor(&dev->control); err_g2: diff --git a/include/drm/drmP.h b/include/drm/drmP.h index d6b67bb..a9ffc81 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -152,6 +152,7 @@ int drm_err(const char *func, const char *format, ...); #define DRIVER_GEM 0x1000 #define DRIVER_MODESET 0x2000 #define DRIVER_PRIME 0x4000 +#define DRIVER_RENDER 0x8000
#define DRIVER_BUS_PCI 0x1 #define DRIVER_BUS_PLATFORM 0x2 @@ -306,6 +307,7 @@ typedef int drm_ioctl_compat_t(struct file *filp, unsigned int cmd, #define DRM_ROOT_ONLY 0x4 #define DRM_CONTROL_ALLOW 0x8 #define DRM_UNLOCKED 0x10 +#define DRM_RENDER_ALLOW 0x20
struct drm_ioctl_desc { unsigned int cmd; @@ -1185,6 +1187,7 @@ struct drm_device { struct drm_local_map *agp_buffer_map; unsigned int agp_buffer_token; struct drm_minor *control; /**< Control node for card */ + struct drm_minor *render; /**< Render node for card */ struct drm_minor *primary; /**< render type primary screen head */
struct drm_mode_config mode_config; /**< Current mode config */