rocket_gem.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright 2024-2025 Tomeu Vizoso <tomeu@tomeuvizoso.net> */
  3
  4#include <drm/drm_device.h>
  5#include <drm/drm_print.h>
  6#include <drm/drm_utils.h>
  7#include <drm/rocket_accel.h>
  8#include <linux/dma-mapping.h>
  9#include <linux/iommu.h>
 10
 11#include "rocket_drv.h"
 12#include "rocket_gem.h"
 13
 14static void rocket_gem_bo_free(struct drm_gem_object *obj)
 15{
 16	struct rocket_gem_object *bo = to_rocket_bo(obj);
 17	struct rocket_file_priv *rocket_priv = bo->driver_priv;
 18	size_t unmapped;
 19
 20	drm_WARN_ON(obj->dev, refcount_read(&bo->base.pages_use_count) > 1);
 21
 22	unmapped = iommu_unmap(bo->domain->domain, bo->mm.start, bo->size);
 23	drm_WARN_ON(obj->dev, unmapped != bo->size);
 24
 25	mutex_lock(&rocket_priv->mm_lock);
 26	drm_mm_remove_node(&bo->mm);
 27	mutex_unlock(&rocket_priv->mm_lock);
 28
 29	rocket_iommu_domain_put(bo->domain);
 30	bo->domain = NULL;
 31
 32	drm_gem_shmem_free(&bo->base);
 33}
 34
 35static const struct drm_gem_object_funcs rocket_gem_funcs = {
 36	.free = rocket_gem_bo_free,
 37	.print_info = drm_gem_shmem_object_print_info,
 38	.pin = drm_gem_shmem_object_pin,
 39	.unpin = drm_gem_shmem_object_unpin,
 40	.get_sg_table = drm_gem_shmem_object_get_sg_table,
 41	.vmap = drm_gem_shmem_object_vmap,
 42	.vunmap = drm_gem_shmem_object_vunmap,
 43	.mmap = drm_gem_shmem_object_mmap,
 44	.vm_ops = &drm_gem_shmem_vm_ops,
 45};
 46
 47struct drm_gem_object *rocket_gem_create_object(struct drm_device *dev, size_t size)
 48{
 49	struct rocket_gem_object *obj;
 50
 51	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 52	if (!obj)
 53		return ERR_PTR(-ENOMEM);
 54
 55	obj->base.base.funcs = &rocket_gem_funcs;
 56
 57	return &obj->base.base;
 58}
 59
 60int rocket_ioctl_create_bo(struct drm_device *dev, void *data, struct drm_file *file)
 61{
 62	struct rocket_file_priv *rocket_priv = file->driver_priv;
 63	struct drm_rocket_create_bo *args = data;
 64	struct drm_gem_shmem_object *shmem_obj;
 65	struct rocket_gem_object *rkt_obj;
 66	struct drm_gem_object *gem_obj;
 67	struct sg_table *sgt;
 68	int ret;
 69
 70	shmem_obj = drm_gem_shmem_create(dev, args->size);
 71	if (IS_ERR(shmem_obj))
 72		return PTR_ERR(shmem_obj);
 73
 74	gem_obj = &shmem_obj->base;
 75	rkt_obj = to_rocket_bo(gem_obj);
 76
 77	rkt_obj->driver_priv = rocket_priv;
 78	rkt_obj->domain = rocket_iommu_domain_get(rocket_priv);
 79	rkt_obj->size = args->size;
 80	rkt_obj->offset = 0;
 81
 82	ret = drm_gem_handle_create(file, gem_obj, &args->handle);
 83	drm_gem_object_put(gem_obj);
 84	if (ret)
 85		goto err;
 86
 87	sgt = drm_gem_shmem_get_pages_sgt(shmem_obj);
 88	if (IS_ERR(sgt)) {
 89		ret = PTR_ERR(sgt);
 90		goto err;
 91	}
 92
 93	mutex_lock(&rocket_priv->mm_lock);
 94	ret = drm_mm_insert_node_generic(&rocket_priv->mm, &rkt_obj->mm,
 95					 rkt_obj->size, PAGE_SIZE,
 96					 0, 0);
 97	mutex_unlock(&rocket_priv->mm_lock);
 98
 99	ret = iommu_map_sgtable(rocket_priv->domain->domain,
100				rkt_obj->mm.start,
101				shmem_obj->sgt,
102				IOMMU_READ | IOMMU_WRITE);
103	if (ret < 0 || ret < args->size) {
104		drm_err(dev, "failed to map buffer: size=%d request_size=%u\n",
105			ret, args->size);
106		ret = -ENOMEM;
107		goto err_remove_node;
108	}
109
110	/* iommu_map_sgtable might have aligned the size */
111	rkt_obj->size = ret;
112	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
113	args->dma_address = rkt_obj->mm.start;
114
115	return 0;
116
117err_remove_node:
118	mutex_lock(&rocket_priv->mm_lock);
119	drm_mm_remove_node(&rkt_obj->mm);
120	mutex_unlock(&rocket_priv->mm_lock);
121
122err:
123	drm_gem_shmem_object_free(gem_obj);
124
125	return ret;
126}
127
128int rocket_ioctl_prep_bo(struct drm_device *dev, void *data, struct drm_file *file)
129{
130	struct drm_rocket_prep_bo *args = data;
131	unsigned long timeout = drm_timeout_abs_to_jiffies(args->timeout_ns);
132	struct drm_gem_object *gem_obj;
133	struct drm_gem_shmem_object *shmem_obj;
134	long ret = 0;
135
136	if (args->reserved != 0) {
137		drm_dbg(dev, "Reserved field in drm_rocket_prep_bo struct should be 0.\n");
138		return -EINVAL;
139	}
140
141	gem_obj = drm_gem_object_lookup(file, args->handle);
142	if (!gem_obj)
143		return -ENOENT;
144
145	ret = dma_resv_wait_timeout(gem_obj->resv, DMA_RESV_USAGE_WRITE, true, timeout);
146	if (!ret)
147		ret = timeout ? -ETIMEDOUT : -EBUSY;
148
149	shmem_obj = &to_rocket_bo(gem_obj)->base;
150
151	dma_sync_sgtable_for_cpu(dev->dev, shmem_obj->sgt, DMA_BIDIRECTIONAL);
152
153	drm_gem_object_put(gem_obj);
154
155	return ret;
156}
157
158int rocket_ioctl_fini_bo(struct drm_device *dev, void *data, struct drm_file *file)
159{
160	struct drm_rocket_fini_bo *args = data;
161	struct drm_gem_shmem_object *shmem_obj;
162	struct rocket_gem_object *rkt_obj;
163	struct drm_gem_object *gem_obj;
164
165	if (args->reserved != 0) {
166		drm_dbg(dev, "Reserved field in drm_rocket_fini_bo struct should be 0.\n");
167		return -EINVAL;
168	}
169
170	gem_obj = drm_gem_object_lookup(file, args->handle);
171	if (!gem_obj)
172		return -ENOENT;
173
174	rkt_obj = to_rocket_bo(gem_obj);
175	shmem_obj = &rkt_obj->base;
176
177	dma_sync_sgtable_for_device(dev->dev, shmem_obj->sgt, DMA_BIDIRECTIONAL);
178
179	drm_gem_object_put(gem_obj);
180
181	return 0;
182}