[PATCH 7/9] accel/rocket: Add IOCTL for BO creation

From: Tomeu Vizoso
Date: Wed Jun 12 2024 - 09:55:44 EST


This uses the SHMEM DRM helpers and we map right away to the CPU and NPU
sides, as all buffers are expected to be accessed from both.

Signed-off-by: Tomeu Vizoso <tomeu@xxxxxxxxxxxxxxx>
---
drivers/accel/rocket/Makefile | 3 +-
drivers/accel/rocket/rocket_drv.c | 7 +++-
drivers/accel/rocket/rocket_gem.c | 68 +++++++++++++++++++++++++++++++++++++++
drivers/accel/rocket/rocket_gem.h | 28 ++++++++++++++++
include/uapi/drm/rocket_accel.h | 24 ++++++++++++++
5 files changed, 128 insertions(+), 2 deletions(-)

diff --git a/drivers/accel/rocket/Makefile b/drivers/accel/rocket/Makefile
index 73a7280d260c..875cac2243d9 100644
--- a/drivers/accel/rocket/Makefile
+++ b/drivers/accel/rocket/Makefile
@@ -5,4 +5,5 @@ obj-$(CONFIG_DRM_ACCEL_ROCKET) := rocket.o
rocket-y := \
rocket_core.o \
rocket_device.o \
- rocket_drv.o
+ rocket_drv.o \
+ rocket_gem.o
diff --git a/drivers/accel/rocket/rocket_drv.c b/drivers/accel/rocket/rocket_drv.c
index e339c337fcf9..42196417030e 100644
--- a/drivers/accel/rocket/rocket_drv.c
+++ b/drivers/accel/rocket/rocket_drv.c
@@ -11,9 +11,11 @@
#include <drm/drm_ioctl.h>
#include <drm/drm_accel.h>
#include <drm/drm_gem.h>
+#include <drm/rocket_accel.h>

#include "rocket_drv.h"
#include "rocket_device.h"
+#include "rocket_gem.h"

static const char * const rk3588_pm_domains[] = { "npu0", "npu1", "npu2" };
static const char * const rk3588_resets_a[] = { "srst_a0", "srst_a1", "srst_a2" };
@@ -58,6 +60,8 @@ rocket_postclose(struct drm_device *dev, struct drm_file *file)
static const struct drm_ioctl_desc rocket_drm_driver_ioctls[] = {
#define ROCKET_IOCTL(n, func) \
DRM_IOCTL_DEF_DRV(ROCKET_##n, rocket_ioctl_##func, 0)
+
+ ROCKET_IOCTL(CREATE_BO, create_bo),
};

static const struct file_operations rocket_drm_driver_fops = {
@@ -70,9 +74,10 @@ static const struct file_operations rocket_drm_driver_fops = {
* - 1.0 - initial interface
*/
static const struct drm_driver rocket_drm_driver = {
- .driver_features = DRIVER_COMPUTE_ACCEL,
+ .driver_features = DRIVER_COMPUTE_ACCEL | DRIVER_GEM,
.open = rocket_open,
.postclose = rocket_postclose,
+ .gem_create_object = rocket_gem_create_object,
.ioctls = rocket_drm_driver_ioctls,
.num_ioctls = ARRAY_SIZE(rocket_drm_driver_ioctls),
.fops = &rocket_drm_driver_fops,
diff --git a/drivers/accel/rocket/rocket_gem.c b/drivers/accel/rocket/rocket_gem.c
new file mode 100644
index 000000000000..e10eb886f150
--- /dev/null
+++ b/drivers/accel/rocket/rocket_gem.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2024 Tomeu Vizoso <tomeu@xxxxxxxxxxxxxxx> */
+
+#include <drm/drm_device.h>
+#include <drm/rocket_accel.h>
+
+#include "rocket_gem.h"
+
+/**
+ * rocket_gem_create_object - Implementation of driver->gem_create_object.
+ * @dev: DRM device
+ * @size: Size in bytes of the memory the object will reference
+ *
+ * This lets the GEM helpers allocate object structs for us, and keep
+ * our BO stats correct.
+ */
+struct drm_gem_object *rocket_gem_create_object(struct drm_device *dev, size_t size)
+{
+ struct rocket_gem_object *obj;
+
+ obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ if (!obj)
+ return ERR_PTR(-ENOMEM);
+
+ return &obj->base.base;
+}
+
+int rocket_ioctl_create_bo(struct drm_device *dev, void *data, struct drm_file *file)
+{
+ struct drm_rocket_create_bo *args = data;
+ struct drm_gem_shmem_object *shmem_obj;
+ struct rocket_gem_object *rkt_obj;
+ struct drm_gem_object *gem_obj;
+ struct sg_table *sgt;
+ int ret;
+
+ shmem_obj = drm_gem_shmem_create(dev, args->size);
+ if (IS_ERR(shmem_obj))
+ return PTR_ERR(shmem_obj);
+
+ gem_obj = &shmem_obj->base;
+ rkt_obj = to_rocket_bo(gem_obj);
+
+ rkt_obj->size = args->size;
+ rkt_obj->offset = 0;
+ mutex_init(&rkt_obj->mutex);
+
+ ret = drm_gem_handle_create(file, gem_obj, &args->handle);
+ drm_gem_object_put(gem_obj);
+ if (ret)
+ goto err;
+
+ sgt = drm_gem_shmem_get_pages_sgt(shmem_obj);
+ if (IS_ERR(sgt)) {
+ ret = PTR_ERR(sgt);
+ goto err;
+ }
+
+ args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
+ args->dma_address = sg_dma_address(shmem_obj->sgt->sgl);
+
+ return 0;
+
+err:
+ drm_gem_shmem_object_free(gem_obj);
+
+ return ret;
+}
diff --git a/drivers/accel/rocket/rocket_gem.h b/drivers/accel/rocket/rocket_gem.h
new file mode 100644
index 000000000000..2cb294f25c19
--- /dev/null
+++ b/drivers/accel/rocket/rocket_gem.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2024 Tomeu Vizoso <tomeu@xxxxxxxxxxxxxxx> */
+
+#ifndef __ROCKET_GEM_H__
+#define __ROCKET_GEM_H__
+
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_mm.h>
+
+struct rocket_gem_object {
+ struct drm_gem_shmem_object base;
+
+ struct mutex mutex;
+ size_t size;
+ u32 offset;
+};
+
+struct drm_gem_object *rocket_gem_create_object(struct drm_device *dev, size_t size);
+
+int rocket_ioctl_create_bo(struct drm_device *dev, void *data, struct drm_file *file);
+
+static inline
+struct rocket_gem_object *to_rocket_bo(struct drm_gem_object *obj)
+{
+ return container_of(to_drm_gem_shmem_obj(obj), struct rocket_gem_object, base);
+}
+
+#endif
\ No newline at end of file
diff --git a/include/uapi/drm/rocket_accel.h b/include/uapi/drm/rocket_accel.h
index 7a179731ffe4..8338726a83c3 100644
--- a/include/uapi/drm/rocket_accel.h
+++ b/include/uapi/drm/rocket_accel.h
@@ -11,6 +11,30 @@
extern "C" {
#endif

+#define DRM_ROCKET_CREATE_BO 0x00
+
+#define DRM_IOCTL_ROCKET_CREATE_BO DRM_IOWR(DRM_COMMAND_BASE + DRM_ROCKET_CREATE_BO, struct drm_rocket_create_bo)
+
+/**
+ * struct drm_rocket_create_bo - ioctl argument for creating Rocket BOs.
+ *
+ */
+struct drm_rocket_create_bo {
+ __u32 size;
+
+ /** Returned GEM handle for the BO. */
+ __u32 handle;
+
+ /**
+ * Returned DMA address for the BO in the NPU address space. This address
+ * is private to the DRM fd and is valid for the lifetime of the GEM
+ * handle.
+ */
+ __u64 dma_address;
+
+ /** Offset into the drm node to use for subsequent mmap call. */
+ __u64 offset;
+};

#if defined(__cplusplus)
}

--
2.45.2