[PATCH 2/7] drm/apu: Add memory allocator

[Alexandre Bailon <abailon@baylibre.com>]

This adds a new ioctl to allocate GEM object.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Reviewed-by: Julien Stephan <jstephan@baylibre.com>
---
 drivers/gpu/drm/apu/Makefile       |  1 +
 drivers/gpu/drm/apu/apu_drv.c      |  2 ++
 drivers/gpu/drm/apu/apu_gem.c      | 56 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/apu/apu_internal.h | 30 ++++++++++++++++
 include/uapi/drm/apu_drm.h         | 16 ++++++++-
 5 files changed, 104 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/apu/apu_gem.c

diff --git a/drivers/gpu/drm/apu/Makefile b/drivers/gpu/drm/apu/Makefile
index ad85b88a8b52..91894250d4c1 100644
--- a/drivers/gpu/drm/apu/Makefile
+++ b/drivers/gpu/drm/apu/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
 drm_apu-y += apu_drv.o
+drm_apu-y += apu_gem.o
 
 obj-$(CONFIG_DRM_APU) += drm_apu.o
diff --git a/drivers/gpu/drm/apu/apu_drv.c b/drivers/gpu/drm/apu/apu_drv.c
index b420b13a9ffd..323e267b0f53 100644
--- a/drivers/gpu/drm/apu/apu_drv.c
+++ b/drivers/gpu/drm/apu/apu_drv.c
@@ -20,6 +20,8 @@ static int ioctl_apu_state(struct drm_device *dev, void *data,
 static const struct drm_ioctl_desc ioctls[] = {
 	DRM_IOCTL_DEF_DRV(APU_STATE, ioctl_apu_state,
 			  DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(APU_GEM_NEW, ioctl_gem_new,
+			  DRM_RENDER_ALLOW),
 };
 
 DEFINE_DRM_GEM_DMA_FOPS(apu_drm_ops);
diff --git a/drivers/gpu/drm/apu/apu_gem.c b/drivers/gpu/drm/apu/apu_gem.c
new file mode 100644
index 000000000000..0e7b3b27942c
--- /dev/null
+++ b/drivers/gpu/drm/apu/apu_gem.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright 2020 BayLibre SAS
+
+#include <drm/drm_gem_dma_helper.h>
+
+#include <uapi/drm/apu_drm.h>
+
+#include "apu_internal.h"
+
+struct drm_gem_object *apu_gem_create_object(struct drm_device *dev,
+					     size_t size)
+{
+	struct drm_gem_dma_object *dma_obj;
+
+	dma_obj = drm_gem_dma_create(dev, size);
+	if (!dma_obj)
+		return NULL;
+
+	return &dma_obj->base;
+}
+
+int ioctl_gem_new(struct drm_device *dev, void *data,
+		  struct drm_file *file_priv)
+{
+	struct drm_apu_gem_new *args = data;
+	struct drm_gem_dma_object *dma_obj;
+	struct apu_gem_object *apu_obj;
+	struct drm_gem_object *gem_obj;
+	int ret;
+
+	dma_obj = drm_gem_dma_create(dev, args->size);
+	if (IS_ERR(dma_obj))
+		return PTR_ERR(dma_obj);
+
+	gem_obj = &dma_obj->base;
+	apu_obj = to_apu_bo(gem_obj);
+
+	/*
+	 * Save the size of buffer expected by application instead of the
+	 * aligned one.
+	 */
+	apu_obj->size = args->size;
+	apu_obj->offset = 0;
+	mutex_init(&apu_obj->mutex);
+
+	ret = drm_gem_handle_create(file_priv, gem_obj, &args->handle);
+	drm_gem_object_put(gem_obj);
+	if (ret) {
+		drm_gem_dma_object_free(gem_obj);
+		return ret;
+	}
+	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/apu/apu_internal.h b/drivers/gpu/drm/apu/apu_internal.h
index 58d93a16c68f..203aadc58b72 100644
--- a/drivers/gpu/drm/apu/apu_internal.h
+++ b/drivers/gpu/drm/apu/apu_internal.h
@@ -3,6 +3,14 @@
 #define __APU_INTERNAL_H__
 
 #include <drm/drm_drv.h>
+#include <drm/drm_gem_dma_helper.h>
+
+struct apu_gem_object {
+	struct drm_gem_dma_object base;
+	struct mutex mutex;
+	size_t size;
+	u32 offset;
+};
 
 struct apu_core {
 	int device_id;
@@ -54,6 +62,17 @@ struct apu_core_ops {
 	int (*is_ready)(struct apu_core *core);
 };
 
+static inline struct apu_gem_object *to_apu_bo(struct drm_gem_object *obj)
+{
+	return container_of(to_drm_gem_dma_obj(obj), struct apu_gem_object,
+			    base);
+}
+
+static inline void *apu_drm_priv(struct apu_core *apu_core)
+{
+	return apu_core->dev_priv;
+}
+
 struct apu_drm *apu_dev_alloc(struct device *dev);
 int apu_dev_register(struct apu_drm *apu);
 void apu_dev_unregister(struct apu_drm *apu);
@@ -65,4 +84,15 @@ int apu_core_register(struct device *dev, struct apu_core *core, void *priv);
 void apu_core_remove(struct apu_core *core);
 struct apu_core *apu_find_core_by_priv(void *priv);
 
+struct apu_gem_object *to_apu_bo(struct drm_gem_object *obj);
+struct drm_gem_object *apu_gem_create_object(struct drm_device *dev,
+					     size_t size);
+
+int ioctl_gem_new(struct drm_device *dev, void *data,
+		  struct drm_file *file_priv);
+int ioctl_gem_user_new(struct drm_device *dev, void *data,
+		       struct drm_file *file_priv);
+struct dma_buf *apu_gem_prime_export(struct drm_gem_object *gem,
+				     int flags);
+
 #endif /* __APU_INTERNAL_H__ */
diff --git a/include/uapi/drm/apu_drm.h b/include/uapi/drm/apu_drm.h
index d50c63d1b813..14fc478f45dc 100644
--- a/include/uapi/drm/apu_drm.h
+++ b/include/uapi/drm/apu_drm.h
@@ -9,6 +9,18 @@
 extern "C" {
 #endif
 
+/*
+ * Please note that modifications to all structs defined here are
+ * subject to backwards-compatibility constraints.
+ */
+
+struct drm_apu_gem_new {
+	__u32 size;			/* in */
+	__u32 flags;			/* in */
+	__u32 handle;			/* out */
+	__u64 offset;			/* out */
+};
+
 #define APU_ONLINE		BIT(0)
 
 struct drm_apu_state {
@@ -17,9 +29,11 @@ struct drm_apu_state {
 };
 
 #define DRM_APU_STATE			0x00
-#define DRM_APU_NUM_IOCTLS		0x01
+#define DRM_APU_GEM_NEW			0x01
+#define DRM_APU_NUM_IOCTLS		0x02
 
 #define DRM_IOCTL_APU_STATE		DRM_IOWR(DRM_COMMAND_BASE + DRM_APU_STATE, struct drm_apu_state)
+#define DRM_IOCTL_APU_GEM_NEW		DRM_IOWR(DRM_COMMAND_BASE + DRM_APU_GEM_NEW, struct drm_apu_gem_new)
 
 #if defined(__cplusplus)
 }
-- 
2.39.2