xref: /linux/drivers/accel/rocket/rocket_gem.c (revision 65b09bfa8aa7ebe087093b591525385efb2d58b0)
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_obj(*obj);
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 	sgt = drm_gem_shmem_get_pages_sgt(shmem_obj);
83 	if (IS_ERR(sgt)) {
84 		ret = PTR_ERR(sgt);
85 		goto err;
86 	}
87 
88 	mutex_lock(&rocket_priv->mm_lock);
89 	ret = drm_mm_insert_node_generic(&rocket_priv->mm, &rkt_obj->mm,
90 					 rkt_obj->size, PAGE_SIZE,
91 					 0, 0);
92 	mutex_unlock(&rocket_priv->mm_lock);
93 	if (ret)
94 		goto err;
95 
96 	ret = iommu_map_sgtable(rocket_priv->domain->domain,
97 				rkt_obj->mm.start,
98 				shmem_obj->sgt,
99 				IOMMU_READ | IOMMU_WRITE);
100 	if (ret < 0 || ret < args->size) {
101 		drm_err(dev, "failed to map buffer: size=%d request_size=%u\n",
102 			ret, args->size);
103 		ret = -ENOMEM;
104 		goto err_remove_node;
105 	}
106 
107 	/* iommu_map_sgtable might have aligned the size */
108 	rkt_obj->size = ret;
109 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
110 	args->dma_address = rkt_obj->mm.start;
111 
112 	ret = drm_gem_handle_create(file, gem_obj, &args->handle);
113 	if (ret)
114 		goto err_unmap;
115 
116 	drm_gem_object_put(gem_obj);
117 
118 	return 0;
119 
120 err_unmap:
121 	iommu_unmap(rocket_priv->domain->domain,
122 		    rkt_obj->mm.start, rkt_obj->size);
123 
124 err_remove_node:
125 	mutex_lock(&rocket_priv->mm_lock);
126 	drm_mm_remove_node(&rkt_obj->mm);
127 	mutex_unlock(&rocket_priv->mm_lock);
128 
129 err:
130 	drm_gem_shmem_object_free(gem_obj);
131 
132 	return ret;
133 }
134 
135 int rocket_ioctl_prep_bo(struct drm_device *dev, void *data, struct drm_file *file)
136 {
137 	struct drm_rocket_prep_bo *args = data;
138 	unsigned long timeout = drm_timeout_abs_to_jiffies(args->timeout_ns);
139 	struct drm_gem_object *gem_obj;
140 	struct drm_gem_shmem_object *shmem_obj;
141 	long ret = 0;
142 
143 	if (args->reserved != 0) {
144 		drm_dbg(dev, "Reserved field in drm_rocket_prep_bo struct should be 0.\n");
145 		return -EINVAL;
146 	}
147 
148 	gem_obj = drm_gem_object_lookup(file, args->handle);
149 	if (!gem_obj)
150 		return -ENOENT;
151 
152 	ret = dma_resv_wait_timeout(gem_obj->resv, DMA_RESV_USAGE_WRITE, true, timeout);
153 	if (!ret)
154 		ret = timeout ? -ETIMEDOUT : -EBUSY;
155 	else if (ret > 0)
156 		ret = 0;
157 
158 	shmem_obj = &to_rocket_bo(gem_obj)->base;
159 
160 	dma_sync_sgtable_for_cpu(dev->dev, shmem_obj->sgt, DMA_BIDIRECTIONAL);
161 
162 	drm_gem_object_put(gem_obj);
163 
164 	return ret;
165 }
166 
167 int rocket_ioctl_fini_bo(struct drm_device *dev, void *data, struct drm_file *file)
168 {
169 	struct drm_rocket_fini_bo *args = data;
170 	struct drm_gem_shmem_object *shmem_obj;
171 	struct rocket_gem_object *rkt_obj;
172 	struct drm_gem_object *gem_obj;
173 
174 	if (args->reserved != 0) {
175 		drm_dbg(dev, "Reserved field in drm_rocket_fini_bo struct should be 0.\n");
176 		return -EINVAL;
177 	}
178 
179 	gem_obj = drm_gem_object_lookup(file, args->handle);
180 	if (!gem_obj)
181 		return -ENOENT;
182 
183 	rkt_obj = to_rocket_bo(gem_obj);
184 	shmem_obj = &rkt_obj->base;
185 
186 	dma_sync_sgtable_for_device(dev->dev, shmem_obj->sgt, DMA_BIDIRECTIONAL);
187 
188 	drm_gem_object_put(gem_obj);
189 
190 	return 0;
191 }
192