[PATCH 13/18] drm/i915/context: create & destroy ioctls

[Ben Widawsky <ben@bwidawsk.net>]

Add the interfaces to allow user space to create and destroy contexts.
Contexts are destroyed automatically if the file descriptor for the dri
device is closed.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_dma.c         |    2 +
 drivers/gpu/drm/i915/i915_drv.h         |    4 ++
 drivers/gpu/drm/i915/i915_gem_context.c |   64 +++++++++++++++++++++++++++++++
 include/drm/i915_drm.h                  |   16 ++++++++
 4 files changed, 86 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 4c7c1dc..fb3fccb 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -2333,6 +2333,8 @@ struct drm_ioctl_desc i915_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(I915_OVERLAY_ATTRS, intel_overlay_attrs, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 	DRM_IOCTL_DEF_DRV(I915_SET_SPRITE_COLORKEY, intel_sprite_set_colorkey, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 	DRM_IOCTL_DEF_DRV(I915_GET_SPRITE_COLORKEY, intel_sprite_get_colorkey, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+	DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_CREATE, i915_gem_context_create_ioctl, DRM_UNLOCKED),
+	DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_DESTROY, i915_gem_context_destroy_ioctl, DRM_UNLOCKED),
 };
 
 int i915_max_ioctl = DRM_ARRAY_SIZE(i915_ioctls);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c6c2ada..d49615e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1312,6 +1312,10 @@ void i915_gem_context_close(struct drm_device *dev, struct drm_file *file);
 int i915_switch_context(struct intel_ring_buffer *ring,
 			struct drm_file *file,
 			int to_id, u32 seqno, u32 flags);
+int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
+				  struct drm_file *file);
+int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
+				   struct drm_file *file);
 
 /* i915_gem_gtt.c */
 int __must_check i915_gem_init_aliasing_ppgtt(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index d9a08f2..accb3de 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -411,3 +411,67 @@ out:
 	kref_put(&to->nref, destroy_hw_context);
 	return ret;
 }
+
+int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
+				  struct drm_file *file)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_gem_context_create *args = data;
+	struct drm_i915_file_private *file_priv = file->driver_priv;
+	struct intel_ring_buffer *ring = &dev_priv->ring[RCS];
+	struct i915_hw_context *ctx;
+	int ret;
+
+	if (dev_priv->hw_contexts_disabled)
+		return -EPERM;
+
+	ret = create_hw_context(dev, file_priv, &ctx);
+	if (ret)
+		return ret;
+
+	/* We need to do a special switch (save-only) either now, or before the
+	 * context is actually used in order to keep the context switch request
+	 * in execbuffer fairly simple.
+	 */
+	mutex_lock(&dev->struct_mutex);
+	ret = i915_switch_context(ring, file, ctx->id, ring->get_seqno(ring),
+				  I915_CONTEXT_INITIAL_SWITCH);
+	mutex_unlock(&dev->struct_mutex);
+	if (ret)
+		return ret;
+
+	args->ctx_id = ctx->id;
+	DRM_DEBUG_DRIVER("HW context %d created\n", args->ctx_id);
+	return ret;
+}
+
+int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
+				   struct drm_file *file)
+{
+	struct drm_i915_gem_context_destroy *args = data;
+	struct drm_i915_file_private *file_priv = file->driver_priv;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct i915_hw_context *ctx;
+
+	if (dev_priv->hw_contexts_disabled)
+		return -EPERM;
+
+	mutex_lock(&dev->struct_mutex);
+	ctx = i915_gem_context_get(file_priv, args->ctx_id);
+	if (!ctx) {
+		mutex_unlock(&dev->struct_mutex);
+		return -EINVAL;
+	}
+
+	/* The first put is for the context ref we got just up above. The second
+	 * put should unref the original ref (and will therefore destroy the context
+	 * unless someone else holds a reference
+	 */
+	kref_put(&ctx->nref, destroy_hw_context);
+	kref_put(&ctx->nref, destroy_hw_context);
+
+	mutex_unlock(&dev->struct_mutex);
+
+	DRM_DEBUG_DRIVER("HW context %d destroyed\n", args->ctx_id);
+	return 0;
+}
diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index da929bb..bead13e 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -200,6 +200,8 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_GEM_EXECBUFFER2	0x29
 #define DRM_I915_GET_SPRITE_COLORKEY	0x2a
 #define DRM_I915_SET_SPRITE_COLORKEY	0x2b
+#define DRM_I915_GEM_CONTEXT_CREATE	0x2c
+#define DRM_I915_GEM_CONTEXT_DESTROY	0x2d
 
 #define DRM_IOCTL_I915_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
 #define DRM_IOCTL_I915_FLUSH		DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -243,6 +245,9 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_OVERLAY_ATTRS	DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_OVERLAY_ATTRS, struct drm_intel_overlay_attrs)
 #define DRM_IOCTL_I915_SET_SPRITE_COLORKEY DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_SET_SPRITE_COLORKEY, struct drm_intel_sprite_colorkey)
 #define DRM_IOCTL_I915_GET_SPRITE_COLORKEY DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_SET_SPRITE_COLORKEY, struct drm_intel_sprite_colorkey)
+#define DRM_IOCTL_I915_GEM_CONTEXT_CREATE	DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_CREATE, struct drm_i915_gem_context_create)
+#define DRM_IOCTL_I915_GEM_CONTEXT_DESTROY	DRM_IOW (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_DESTROY, struct drm_i915_gem_context_destroy)
+
 
 /* Allow drivers to submit batchbuffers directly to hardware, relying
  * on the security mechanisms provided by hardware.
@@ -885,4 +890,15 @@ struct drm_intel_sprite_colorkey {
 	__u32 flags;
 };
 
+struct drm_i915_gem_context_create {
+	/* output: id of new context*/
+	__u32 ctx_id;
+	__u32 pad;
+};
+
+struct drm_i915_gem_context_destroy {
+	__u32 ctx_id;
+	__u32 pad;
+};
+
 #endif				/* _I915_DRM_H_ */
-- 
1.7.9.4