xref: /linux/drivers/accel/rocket/rocket_gem.c (revision 6dfafbd0299a60bfb5d5e277fdf100037c7ded07)
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 
14 static 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 
35 static 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 
47 struct 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 
60 int 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 
117 err_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 
122 err:
123 	drm_gem_shmem_object_free(gem_obj);
124 
125 	return ret;
126 }
127 
128 int 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 
158 int 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 }
183