Hi
Am 25.02.25 um 08:55 schrieb Tomeu Vizoso:
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.
v2:
- Sync the IOMMUs for the other cores when mapping and unmapping.
Signed-off-by: Tomeu Vizoso <tomeu@xxxxxxxxxxxxxxx>
---
drivers/accel/rocket/Makefile | 3 +-
drivers/accel/rocket/rocket_device.c | 4 +
drivers/accel/rocket/rocket_device.h | 2 +
drivers/accel/rocket/rocket_drv.c | 7 +-
drivers/accel/rocket/rocket_gem.c | 141 +++++++++++++++++++++++++++++++++++
drivers/accel/rocket/rocket_gem.h | 27 +++++++
include/uapi/drm/rocket_accel.h | 43 +++++++++++
7 files changed, 225 insertions(+), 2 deletions(-)
diff --git a/drivers/accel/rocket/Makefile b/drivers/accel/rocket/Makefile
index 73a7280d260c068d37ad3048824f710482333540..875cac2243d902694e0d5d05e60b4ae551a633c4 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_device.c b/drivers/accel/rocket/rocket_device.c
index ce3b533f15c1011d8a7a23dd8132e907cc334c58..9af36357caba7148dcac764c8222699f3b572d60 100644
--- a/drivers/accel/rocket/rocket_device.c
+++ b/drivers/accel/rocket/rocket_device.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright 2024 Tomeu Vizoso <tomeu@xxxxxxxxxxxxxxx> */
+#include "linux/mutex.h"
Include with angle brackets please.
#include <linux/clk.h>
#include "rocket_device.h"
@@ -10,6 +11,8 @@ int rocket_device_init(struct rocket_device *rdev)
struct device *dev = rdev->cores[0].dev;
int err;
+ mutex_init(&rdev->iommu_lock);
In DRM, we have drmm_mutex_init() in drm/drm_managed.h. Managed cleanup
is generally preferred.
+
rdev->clk_npu = devm_clk_get(dev, "npu");
rdev->pclk = devm_clk_get(dev, "pclk");
@@ -26,4 +29,5 @@ int rocket_device_init(struct rocket_device *rdev)
void rocket_device_fini(struct rocket_device *rdev)
{
rocket_core_fini(&rdev->cores[0]);
+ mutex_destroy(&rdev->iommu_lock);
}
diff --git a/drivers/accel/rocket/rocket_device.h b/drivers/accel/rocket/rocket_device.h
index 466edba9102c5dc5dfac5d3fcc1c904f206eaebb..c6152569fdd9e5587c8e8d7b0d7c2e2a77af6000 100644
--- a/drivers/accel/rocket/rocket_device.h
+++ b/drivers/accel/rocket/rocket_device.h
@@ -14,6 +14,8 @@ struct rocket_device {
struct clk *clk_npu;
struct clk *pclk;
+ struct mutex iommu_lock;
+
struct rocket_core *cores;
unsigned int num_cores;
};
diff --git a/drivers/accel/rocket/rocket_drv.c b/drivers/accel/rocket/rocket_drv.c
index c22d965f20f1239a36b1d823d5fe5f372713555d..e5612b52952fa7a0cd0af02aef314984bc483b05 100644
--- a/drivers/accel/rocket/rocket_drv.c
+++ b/drivers/accel/rocket/rocket_drv.c
@@ -6,6 +6,7 @@
#include <drm/drm_gem.h>
#include <drm/drm_ioctl.h>
#include <drm/drm_of.h>
+#include <drm/rocket_accel.h>
#include <linux/clk.h>
#include <linux/component.h>
#include <linux/dma-mapping.h>
@@ -14,6 +15,7 @@
#include <linux/pm_runtime.h>
#include "rocket_drv.h"
+#include "rocket_gem.h"
static int
rocket_open(struct drm_device *dev, struct drm_file *file)
@@ -42,6 +44,8 @@ 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),
};
DEFINE_DRM_ACCEL_FOPS(rocket_accel_driver_fops);
@@ -51,9 +55,10 @@ DEFINE_DRM_ACCEL_FOPS(rocket_accel_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_accel_driver_fops,
diff --git a/drivers/accel/rocket/rocket_gem.c b/drivers/accel/rocket/rocket_gem.c
new file mode 100644
index 0000000000000000000000000000000000000000..d5337cf1e275c249a1491d0dd28e6b8ccd2ff2cb
--- /dev/null
+++ b/drivers/accel/rocket/rocket_gem.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2024 Tomeu Vizoso <tomeu@xxxxxxxxxxxxxxx> */
+
+#include <drm/drm_device.h>
+#include <drm/drm_utils.h>
+#include <drm/rocket_accel.h>
+#include <linux/dma-mapping.h>
+#include <linux/iommu.h>
+
+#include "rocket_device.h"
+#include "rocket_gem.h"
+
+static void rocket_gem_bo_free(struct drm_gem_object *obj)
+{
+ struct rocket_device *rdev = to_rocket_device(obj->dev);
+ struct rocket_gem_object *bo = to_rocket_bo(obj);
+ struct sg_table *sgt;
+
+ drm_WARN_ON(obj->dev, bo->base.pages_use_count > 1);
+
+ mutex_lock(&rdev->iommu_lock);
+
+ sgt = drm_gem_shmem_get_pages_sgt(&bo->base);
+
+ /* Unmap this object from the IOMMUs for cores > 0 */
+ for (unsigned int core = 1; core < rdev->num_cores; core++) {
+ struct iommu_domain *domain = iommu_get_domain_for_dev(rdev->cores[core].dev);
+ size_t unmapped = iommu_unmap(domain, sgt->sgl->dma_address, bo->size);
+
+ drm_WARN_ON(obj->dev, unmapped != bo->size);
+ }
+
+ /* This will unmap the pages from the IOMMU linked to core 0 */
+ drm_gem_shmem_free(&bo->base);
+
+ mutex_unlock(&rdev->iommu_lock);
+}
+
+static const struct drm_gem_object_funcs rocket_gem_funcs = {
+ .free = rocket_gem_bo_free,
+ .print_info = drm_gem_shmem_object_print_info,
+ .pin = drm_gem_shmem_object_pin,
+ .unpin = drm_gem_shmem_object_unpin,
+ .get_sg_table = drm_gem_shmem_object_get_sg_table,
+ .vmap = drm_gem_shmem_object_vmap,
+ .vunmap = drm_gem_shmem_object_vunmap,
+ .mmap = drm_gem_shmem_object_mmap,
+ .vm_ops = &drm_gem_shmem_vm_ops,
+};
+
+/**
+ * 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);
+
+ obj->base.base.funcs = &rocket_gem_funcs;
+
+ 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 rocket_device *rdev = to_rocket_device(dev);
+ 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;
+
+ mutex_lock(&rdev->iommu_lock);
+
+ /* This will map the pages to the IOMMU linked to core 0 */
+ sgt = drm_gem_shmem_get_pages_sgt(shmem_obj);
+ if (IS_ERR(sgt)) {
+ ret = PTR_ERR(sgt);
+ goto err_unlock;
+ }
+
+ /* Map the pages to the IOMMUs linked to the other cores, so all cores can access this BO */
+ for (unsigned int core = 1; core < rdev->num_cores; core++) {
+
+ ret = iommu_map_sgtable(iommu_get_domain_for_dev(rdev->cores[core].dev),
+ sgt->sgl->dma_address,
+ sgt,
+ IOMMU_READ | IOMMU_WRITE);
+ if (ret < 0 || ret < args->size) {
+ DRM_ERROR("failed to map buffer: size=%d request_size=%u\n",
+ ret, args->size);
+ ret = -ENOMEM;
+ goto err_unlock;
+ }
+
+ /* iommu_map_sgtable might have aligned the size */
+ rkt_obj->size = ret;
+
+ dma_sync_sgtable_for_device(rdev->cores[core].dev, shmem_obj->sgt,
+ DMA_BIDIRECTIONAL);
+ }
+
+ mutex_unlock(&rdev->iommu_lock);
+
+ args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
+ args->dma_address = sg_dma_address(shmem_obj->sgt->sgl);
+
+ return 0;
+
+err_unlock:
+ mutex_unlock(&rdev->iommu_lock);
+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 0000000000000000000000000000000000000000..19b0cf91ddd99bd126c1af30beb169d6101f6dee
--- /dev/null
+++ b/drivers/accel/rocket/rocket_gem.h
@@ -0,0 +1,27 @@
+/* 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>
+
+struct rocket_gem_object {
+ struct drm_gem_shmem_object base;
+
+ struct mutex mutex;
You init this mutex, but never destroy it.
I strongly recommend to scratch all per-object locks and use the
object's reservation lock instead (found in base.resv), if possible.
With multiple locks and dma-buf buffer sharing, there's otherwise
endless fun from getting the locking order right.
+ 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
diff --git a/include/uapi/drm/rocket_accel.h b/include/uapi/drm/rocket_accel.h
new file mode 100644
index 0000000000000000000000000000000000000000..8338726a83c31b954608ca505cf78bcd70d3494b
--- /dev/null
+++ b/include/uapi/drm/rocket_accel.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2024 Tomeu Vizoso
+ */
+#ifndef _ROCKET_DRM_H_
+#define _ROCKET_DRM_H_
For UAPI headers, it makes sense to use a more verbose include guard;
say __DRM_UAPI_ROCKET_ACCEL_H__. Avoids possible conflicts.
Best regards
Thomas
+
+#include "drm.h"
+
+#if defined(__cplusplus)
+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)
+}
+#endif
+
+#endif /* _ROCKET_DRM_H_ */
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
