Commit 658ebeac authored by Tomeu Vizoso's avatar Tomeu Vizoso Committed by Jeff Hugo
Browse files

accel/rocket: Add IOCTL for BO creation 



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.

v3:
- Make use of GPL-2.0-only for the copyright notice (Jeff Hugo)

v6:
- Use mutexes guard (Markus Elfring)

v7:
- Assign its own IOMMU domain to each client, for isolation (Daniel
  Stone and Robin Murphy)

v8:
- Correctly acquire a reference to the IOMMU (Robin Murphy)
- Allocate DMA address ourselves with drm_mm (Robin Murphy)
- Use refcount_read (Heiko Stuebner)
- Remove superfluous dma_sync_sgtable_for_device (Robin Murphy)

Reviewed-by: default avatarJeffrey Hugo <quic_jhugo@quicinc.com>
Tested-by: default avatarHeiko Stuebner <heiko@sntech.de>
Signed-off-by: default avatarTomeu Vizoso <tomeu@tomeuvizoso.net>
Signed-off-by: default avatarJeff Hugo <jeff.hugo@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250721-6-10-rocket-v9-3-77ebd484941e@tomeuvizoso.net
parent ed98261b

drivers/accel/rocket/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -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

drivers/accel/rocket/rocket_drv.c

+14 −1
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <drm/drm_drv.h>

#include <drm/drm_gem.h>

#include <drm/drm_ioctl.h>

#include <drm/rocket_accel.h>

#include <linux/clk.h>

#include <linux/err.h>

#include <linux/iommu.h>
@@ -13,6 +14,7 @@ 
#include <linux/pm_runtime.h>



#include "rocket_drv.h"

#include "rocket_gem.h"



/*

 * Facade device, used to expose a single DRM device to userspace, that
@@ -69,6 +71,7 @@ rocket_open(struct drm_device *dev, struct drm_file *file) 
{

	struct rocket_device *rdev = to_rocket_device(dev);

	struct rocket_file_priv *rocket_priv;

	u64 start, end;

	int ret;



	if (!try_module_get(THIS_MODULE))
@@ -89,6 +92,11 @@ rocket_open(struct drm_device *dev, struct drm_file *file) 


	file->driver_priv = rocket_priv;



	start = rocket_priv->domain->domain->geometry.aperture_start;

	end = rocket_priv->domain->domain->geometry.aperture_end;

	drm_mm_init(&rocket_priv->mm, start, end - start + 1);

	mutex_init(&rocket_priv->mm_lock);



	return 0;



err_free:
@@ -103,6 +111,8 @@ rocket_postclose(struct drm_device *dev, struct drm_file *file) 
{

	struct rocket_file_priv *rocket_priv = file->driver_priv;



	mutex_destroy(&rocket_priv->mm_lock);

	drm_mm_takedown(&rocket_priv->mm);

	rocket_iommu_domain_put(rocket_priv->domain);

	kfree(rocket_priv);

	module_put(THIS_MODULE);
@@ -111,6 +121,8 @@ 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);
@@ -120,9 +132,10 @@ 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,

drivers/accel/rocket/rocket_drv.h

+4 −0
Original line number Diff line number Diff line
@@ -4,6 +4,8 @@ 
#ifndef __ROCKET_DRV_H__

#define __ROCKET_DRV_H__



#include <drm/drm_mm.h>



#include "rocket_device.h"



struct rocket_iommu_domain {
@@ -15,6 +17,8 @@ struct rocket_file_priv { 
	struct rocket_device *rdev;



	struct rocket_iommu_domain *domain;

	struct drm_mm mm;

	struct mutex mm_lock;

};



struct rocket_iommu_domain *rocket_iommu_domain_get(struct rocket_file_priv *rocket_priv);

drivers/accel/rocket/rocket_gem.c

0 → 100644
+125 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* Copyright 2024-2025 Tomeu Vizoso <tomeu@tomeuvizoso.net> */



#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_drv.h"

#include "rocket_gem.h"



static void rocket_gem_bo_free(struct drm_gem_object *obj)

{

	struct rocket_gem_object *bo = to_rocket_bo(obj);

	struct rocket_file_priv *rocket_priv = bo->driver_priv;

	size_t unmapped;



	drm_WARN_ON(obj->dev, refcount_read(&bo->base.pages_use_count) > 1);



	unmapped = iommu_unmap(bo->domain->domain, bo->mm.start, bo->size);

	drm_WARN_ON(obj->dev, unmapped != bo->size);



	mutex_lock(&rocket_priv->mm_lock);

	drm_mm_remove_node(&bo->mm);

	mutex_unlock(&rocket_priv->mm_lock);



	rocket_iommu_domain_put(bo->domain);

	bo->domain = NULL;



	drm_gem_shmem_free(&bo->base);

}



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,

};



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 rocket_file_priv *rocket_priv = file->driver_priv;

	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->driver_priv = rocket_priv;

	rkt_obj->domain = rocket_iommu_domain_get(rocket_priv);

	rkt_obj->size = args->size;

	rkt_obj->offset = 0;



	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;

	}



	mutex_lock(&rocket_priv->mm_lock);

	ret = drm_mm_insert_node_generic(&rocket_priv->mm, &rkt_obj->mm,

					 rkt_obj->size, PAGE_SIZE,

					 0, 0);

	mutex_unlock(&rocket_priv->mm_lock);



	ret = iommu_map_sgtable(rocket_priv->domain->domain,

				rkt_obj->mm.start,

				shmem_obj->sgt,

				IOMMU_READ | IOMMU_WRITE);

	if (ret < 0 || ret < args->size) {

		drm_err(dev, "failed to map buffer: size=%d request_size=%u\n",

			ret, args->size);

		ret = -ENOMEM;

		goto err_remove_node;

	}



	/* iommu_map_sgtable might have aligned the size */

	rkt_obj->size = ret;

	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);

	args->dma_address = rkt_obj->mm.start;



	return 0;



err_remove_node:

	mutex_lock(&rocket_priv->mm_lock);

	drm_mm_remove_node(&rkt_obj->mm);

	mutex_unlock(&rocket_priv->mm_lock);



err:

	drm_gem_shmem_object_free(gem_obj);



	return ret;

}

drivers/accel/rocket/rocket_gem.h

0 → 100644
+30 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/* Copyright 2024-2025 Tomeu Vizoso <tomeu@tomeuvizoso.net> */



#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 rocket_file_priv *driver_priv;



	struct rocket_iommu_domain *domain;

	struct drm_mm_node mm;

	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