drm: dumb scanout create/mmap for intel/radeon (v3)

This is just an idea that might or might not be a good idea,
it basically adds two ioctls to create a dumb and map a dumb buffer
suitable for scanout. The handle can be passed to the KMS ioctls to create
a framebuffer.

It looks to me like it would be useful in the following cases:
a) in development drivers - we can always provide a shadowfb fallback.
b) libkms users - we can clean up libkms a lot and avoid linking
to libdrm_*.
c) plymouth via libkms is a lot easier.

Userspace bits would be just calls + mmaps. We could probably
mark these handles somehow as not being suitable for acceleartion
so as top stop people who are dumber than dumb.

Signed-off-by: Dave Airlie <airlied@redhat.com>

11 files changed, 194 insertions, 38 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 654faa803dcb..4c95b5fd9df3 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2694,3 +2694,36 @@ void drm_mode_config_reset(struct drm_device *dev)
                         connector->funcs->reset(connector);
 }
 EXPORT_SYMBOL(drm_mode_config_reset);
+
+int drm_mode_create_dumb_ioctl(struct drm_device *dev,
+                               void *data, struct drm_file *file_priv)
+{
+        struct drm_mode_create_dumb *args = data;
+
+        if (!dev->driver->dumb_create)
+                return -ENOSYS;
+        return dev->driver->dumb_create(file_priv, dev, args);
+}
+
+int drm_mode_mmap_dumb_ioctl(struct drm_device *dev,
+                             void *data, struct drm_file *file_priv)
+{
+        struct drm_mode_map_dumb *args = data;
+
+        /* call driver ioctl to get mmap offset */
+        if (!dev->driver->dumb_map_offset)
+                return -ENOSYS;
+
+        return dev->driver->dumb_map_offset(file_priv, dev, args->handle, &args->offset);
+}
+
+int drm_mode_destroy_dumb_ioctl(struct drm_device *dev,
+                                void *data, struct drm_file *file_priv)
+{
+        struct drm_mode_destroy_dumb *args = data;
+
+        if (!dev->driver->dumb_destroy)
+                return -ENOSYS;
+
+        return dev->driver->dumb_destroy(file_priv, dev, args->handle);
+}
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 271835a71570..3e991980cee2 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -150,7 +150,10 @@ static struct drm_ioctl_desc drm_ioctls[] = {
         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
         DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
         DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
-        DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED)
+        DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+        DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+        DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+        DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED)
 };
 
 #define DRM_CORE_IOCTL_COUNT    ARRAY_SIZE( drm_ioctls )
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index ea1c4b019ebf..aa8df2534819 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -181,7 +181,7 @@ EXPORT_SYMBOL(drm_gem_object_alloc);
 /**
  * Removes the mapping from handle to filp for this object.
  */
-static int
+int
 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
 {
         struct drm_device *dev;
@@ -214,6 +214,7 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle)
 
         return 0;
 }
+EXPORT_SYMBOL(drm_gem_handle_delete);
 
 /**
  * Create a handle for this object. This adds a handle reference
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index cfb56d0ff367..17fde2f27418 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -700,6 +700,9 @@ static struct drm_driver driver = {
         .gem_init_object = i915_gem_init_object,
         .gem_free_object = i915_gem_free_object,
         .gem_vm_ops = &i915_gem_vm_ops,
+        .dumb_create = i915_gem_dumb_create,
+        .dumb_map_offset = i915_gem_mmap_gtt,
+        .dumb_destroy = i915_gem_dumb_destroy,
         .ioctls = i915_ioctls,
         .fops = {
                  .owner = THIS_MODULE,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a0149c619cdd..a78197d43ce6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1114,6 +1114,13 @@ void i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
                                     struct intel_ring_buffer *ring,
                                     u32 seqno);
 
+int i915_gem_dumb_create(struct drm_file *file_priv,
+                         struct drm_device *dev,
+                         struct drm_mode_create_dumb *args);
+int i915_gem_mmap_gtt(struct drm_file *file_priv, struct drm_device *dev,
+                      uint32_t handle, uint64_t *offset);
+int i915_gem_dumb_destroy(struct drm_file *file_priv, struct drm_device *dev,
+                          uint32_t handle);                       
 /**
  * Returns true if seq1 is later than seq2.
  */
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index cf4f74c7c6fb..bc7f06b8fbca 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -193,22 +193,20 @@ i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
         return 0;
 }
 
-/**
- * Creates a new mm object and returns a handle to it.
- */
-int
-i915_gem_create_ioctl(struct drm_device *dev, void *data,
-                      struct drm_file *file)
+static int
+i915_gem_create(struct drm_file *file,
+                struct drm_device *dev,
+                uint64_t size,
+                uint32_t *handle_p)
 {
-        struct drm_i915_gem_create *args = data;
         struct drm_i915_gem_object *obj;
         int ret;
         u32 handle;
 
-        args->size = roundup(args->size, PAGE_SIZE);
+        size = roundup(size, PAGE_SIZE);
 
         /* Allocate the new object */
-        obj = i915_gem_alloc_object(dev, args->size);
+        obj = i915_gem_alloc_object(dev, size);
         if (obj == NULL)
                 return -ENOMEM;
 
@@ -224,10 +222,41 @@ i915_gem_create_ioctl(struct drm_device *dev, void *data,
         drm_gem_object_unreference(&obj->base);
         trace_i915_gem_object_create(obj);
 
-        args->handle = handle;
+        *handle_p = handle;
         return 0;
 }
 
+int
+i915_gem_dumb_create(struct drm_file *file,
+                     struct drm_device *dev,
+                     struct drm_mode_create_dumb *args)
+{
+        /* have to work out size/pitch and return them */
+        args->pitch = ALIGN(args->width & ((args->bpp + 1) / 8), 64);
+        args->size = args->pitch * args->height;
+        return i915_gem_create(file, dev,
+                               args->size, &args->handle);
+}
+
+int i915_gem_dumb_destroy(struct drm_file *file,
+                          struct drm_device *dev,
+                          uint32_t handle)
+{
+        return drm_gem_handle_delete(file, handle);
+}
+
+/**
+ * Creates a new mm object and returns a handle to it.
+ */
+int
+i915_gem_create_ioctl(struct drm_device *dev, void *data,
+                      struct drm_file *file)
+{
+        struct drm_i915_gem_create *args = data;
+        return i915_gem_create(file, dev,
+                               args->size, &args->handle);
+}
+
 static int i915_gem_object_needs_bit17_swizzle(struct drm_i915_gem_object *obj)
 {
         drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
@@ -1425,27 +1454,13 @@ i915_gem_get_unfenced_gtt_alignment(struct drm_i915_gem_object *obj)
         return tile_height * obj->stride * 2;
 }
 
-/**
- * i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
- * @dev: DRM device
- * @data: GTT mapping ioctl data
- * @file: GEM object info
- *
- * Simply returns the fake offset to userspace so it can mmap it.
- * The mmap call will end up in drm_gem_mmap(), which will set things
- * up so we can get faults in the handler above.
- *
- * The fault handler will take care of binding the object into the GTT
- * (since it may have been evicted to make room for something), allocating
- * a fence register, and mapping the appropriate aperture address into
- * userspace.
- */
 int
-i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
-                        struct drm_file *file)
+i915_gem_mmap_gtt(struct drm_file *file,
+                  struct drm_device *dev,
+                  uint32_t handle,
+                  uint64_t *offset)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
-        struct drm_i915_gem_mmap_gtt *args = data;
         struct drm_i915_gem_object *obj;
         int ret;
 
@@ -1456,7 +1471,7 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
         if (ret)
                 return ret;
 
-        obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
+        obj = to_intel_bo(drm_gem_object_lookup(dev, file, handle));
         if (obj == NULL) {
                 ret = -ENOENT;
                 goto unlock;
@@ -1479,7 +1494,7 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
                         goto out;
         }
 
-        args->offset = (u64)obj->base.map_list.hash.key << PAGE_SHIFT;
+        *offset = (u64)obj->base.map_list.hash.key << PAGE_SHIFT;
 
 out:
         drm_gem_object_unreference(&obj->base);
@@ -1488,6 +1503,34 @@ unlock:
         return ret;
 }
 
+/**
+ * i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
+ * @dev: DRM device
+ * @data: GTT mapping ioctl data
+ * @file: GEM object info
+ *
+ * Simply returns the fake offset to userspace so it can mmap it.
+ * The mmap call will end up in drm_gem_mmap(), which will set things
+ * up so we can get faults in the handler above.
+ *
+ * The fault handler will take care of binding the object into the GTT
+ * (since it may have been evicted to make room for something), allocating
+ * a fence register, and mapping the appropriate aperture address into
+ * userspace.
+ */
+int
+i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
+                        struct drm_file *file)
+{
+        struct drm_i915_gem_mmap_gtt *args = data;
+
+        if (!(dev->driver->driver_features & DRIVER_GEM))
+                return -ENODEV;
+
+        return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
+}
+
+
 static int
 i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj,
                               gfp_t gfpmask)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 56c48b67ef3d..a4605362c528 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -288,6 +288,15 @@ int radeon_gem_object_pin(struct drm_gem_object *obj, uint32_t pin_domain,
                           uint64_t *gpu_addr);
 void radeon_gem_object_unpin(struct drm_gem_object *obj);
 
+int radeon_mode_dumb_create(struct drm_file *file_priv,
+                            struct drm_device *dev,
+                            struct drm_mode_create_dumb *args);
+int radeon_mode_dumb_mmap(struct drm_file *filp,
+                          struct drm_device *dev,
+                          uint32_t handle, uint64_t *offset_p);
+int radeon_mode_dumb_destroy(struct drm_file *file_priv,
+                             struct drm_device *dev,
+                             uint32_t handle);
 
 /*
  * GART structures, functions & helpers
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index 275b26a708d6..ca1b7d4c1d83 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -84,6 +84,16 @@ extern int radeon_get_crtc_scanoutpos(struct drm_device *dev, int crtc,
 extern struct drm_ioctl_desc radeon_ioctls_kms[];
 extern int radeon_max_kms_ioctl;
 int radeon_mmap(struct file *filp, struct vm_area_struct *vma);
+int radeon_mode_dumb_mmap(struct drm_file *filp,
+                          struct drm_device *dev,
+                          uint32_t handle, uint64_t *offset_p);
+int radeon_mode_dumb_create(struct drm_file *file_priv,
+                            struct drm_device *dev,
+                            struct drm_mode_create_dumb *args);
+int radeon_mode_dumb_destroy(struct drm_file *file_priv,
+                             struct drm_device *dev,
+                             uint32_t handle);
+
 #if defined(CONFIG_DEBUG_FS)
 int radeon_debugfs_init(struct drm_minor *minor);
 void radeon_debugfs_cleanup(struct drm_minor *minor);
@@ -322,6 +332,9 @@ static struct drm_driver kms_driver = {
         .gem_init_object = radeon_gem_object_init,
         .gem_free_object = radeon_gem_object_free,
         .dma_ioctl = radeon_dma_ioctl_kms,
+        .dumb_create = radeon_mode_dumb_create,
+        .dumb_map_offset = radeon_mode_dumb_mmap,
+        .dumb_destroy = radeon_mode_dumb_destroy,
         .fops = {
                  .owner = THIS_MODULE,
                  .open = drm_open,
diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c
index 66324b5bb5ba..cb968f997ce7 100644
--- a/drivers/gpu/drm/radeon/radeon_fb.c
+++ b/drivers/gpu/drm/radeon/radeon_fb.c
@@ -64,7 +64,7 @@ static struct fb_ops radeonfb_ops = {
 };
 
 
-static int radeon_align_pitch(struct radeon_device *rdev, int width, int bpp, bool tiled)
+int radeon_align_pitch(struct radeon_device *rdev, int width, int bpp, bool tiled)
 {
         int aligned = width;
         int align_large = (ASIC_IS_AVIVO(rdev)) || tiled;
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index df95eb83dac6..ede5dccdf79f 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -236,23 +236,31 @@ int radeon_gem_set_domain_ioctl(struct drm_device *dev, void *data,
         return r;
 }
 
-int radeon_gem_mmap_ioctl(struct drm_device *dev, void *data,
-                          struct drm_file *filp)
+int radeon_mode_dumb_mmap(struct drm_file *filp,
+                          struct drm_device *dev,
+                          uint32_t handle, uint64_t *offset_p)
 {
-        struct drm_radeon_gem_mmap *args = data;
         struct drm_gem_object *gobj;
         struct radeon_bo *robj;
 
-        gobj = drm_gem_object_lookup(dev, filp, args->handle);
+        gobj = drm_gem_object_lookup(dev, filp, handle);
         if (gobj == NULL) {
                 return -ENOENT;
         }
         robj = gobj->driver_private;
-        args->addr_ptr = radeon_bo_mmap_offset(robj);
+        *offset_p = radeon_bo_mmap_offset(robj);
         drm_gem_object_unreference_unlocked(gobj);
         return 0;
 }
 
+int radeon_gem_mmap_ioctl(struct drm_device *dev, void *data,
+                          struct drm_file *filp)
+{
+        struct drm_radeon_gem_mmap *args = data;
+
+        return radeon_mode_dumb_mmap(filp, dev, args->handle, &args->addr_ptr);
+}
+
 int radeon_gem_busy_ioctl(struct drm_device *dev, void *data,
                           struct drm_file *filp)
 {
@@ -345,3 +353,38 @@ out:
         drm_gem_object_unreference_unlocked(gobj);
         return r;
 }
+
+int radeon_mode_dumb_create(struct drm_file *file_priv,
+                            struct drm_device *dev,
+                            struct drm_mode_create_dumb *args)
+{
+        struct radeon_device *rdev = dev->dev_private;
+        struct drm_gem_object *gobj;
+        int r;
+
+        args->pitch = radeon_align_pitch(rdev, args->width, args->bpp, 0) * ((args->bpp + 1) / 8);
+        args->size = args->pitch * args->height;
+        args->size = ALIGN(args->size, PAGE_SIZE);
+
+        r = radeon_gem_object_create(rdev, args->size, 0,
+                                     RADEON_GEM_DOMAIN_VRAM,
+                                     false, ttm_bo_type_device,
+                                     &gobj);
+        if (r)
+                return -ENOMEM;
+
+        r = drm_gem_handle_create(file_priv, gobj, &args->handle);
+        if (r) {
+                drm_gem_object_unreference_unlocked(gobj);
+                return r;
+        }
+        drm_gem_object_handle_unreference_unlocked(gobj);
+        return 0;
+}
+
+int radeon_mode_dumb_destroy(struct drm_file *file_priv,
+                             struct drm_device *dev,
+                             uint32_t handle)
+{
+        return drm_gem_handle_delete(file_priv, handle);
+}
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 6794cdf91f28..c3f23f6ff60e 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -675,4 +675,5 @@ void radeon_fb_output_poll_changed(struct radeon_device *rdev);
 
 void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id);
 
+int radeon_align_pitch(struct radeon_device *rdev, int width, int bpp, bool tiled);
 #endif