xref: /linux/drivers/gpu/drm/i915/i915_query.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2018 Intel Corporation
5  */
6 
7 #include <linux/nospec.h>
8 
9 #include "i915_drv.h"
10 #include "i915_query.h"
11 #include <uapi/drm/i915_drm.h>
12 
13 static int copy_query_item(void *query_hdr, size_t query_sz,
14 			   u32 total_length,
15 			   struct drm_i915_query_item *query_item)
16 {
17 	if (query_item->length == 0)
18 		return total_length;
19 
20 	if (query_item->length < total_length)
21 		return -EINVAL;
22 
23 	if (copy_from_user(query_hdr, u64_to_user_ptr(query_item->data_ptr),
24 			   query_sz))
25 		return -EFAULT;
26 
27 	if (!access_ok(u64_to_user_ptr(query_item->data_ptr),
28 		       total_length))
29 		return -EFAULT;
30 
31 	return 0;
32 }
33 
34 static int query_topology_info(struct drm_i915_private *dev_priv,
35 			       struct drm_i915_query_item *query_item)
36 {
37 	const struct sseu_dev_info *sseu = &RUNTIME_INFO(dev_priv)->sseu;
38 	struct drm_i915_query_topology_info topo;
39 	u32 slice_length, subslice_length, eu_length, total_length;
40 	u8 subslice_stride = GEN_SSEU_STRIDE(sseu->max_subslices);
41 	u8 eu_stride = GEN_SSEU_STRIDE(sseu->max_eus_per_subslice);
42 	int ret;
43 
44 	if (query_item->flags != 0)
45 		return -EINVAL;
46 
47 	if (sseu->max_slices == 0)
48 		return -ENODEV;
49 
50 	BUILD_BUG_ON(sizeof(u8) != sizeof(sseu->slice_mask));
51 
52 	slice_length = sizeof(sseu->slice_mask);
53 	subslice_length = sseu->max_slices * subslice_stride;
54 	eu_length = sseu->max_slices * sseu->max_subslices * eu_stride;
55 	total_length = sizeof(topo) + slice_length + subslice_length +
56 		       eu_length;
57 
58 	ret = copy_query_item(&topo, sizeof(topo), total_length,
59 			      query_item);
60 	if (ret != 0)
61 		return ret;
62 
63 	if (topo.flags != 0)
64 		return -EINVAL;
65 
66 	memset(&topo, 0, sizeof(topo));
67 	topo.max_slices = sseu->max_slices;
68 	topo.max_subslices = sseu->max_subslices;
69 	topo.max_eus_per_subslice = sseu->max_eus_per_subslice;
70 
71 	topo.subslice_offset = slice_length;
72 	topo.subslice_stride = subslice_stride;
73 	topo.eu_offset = slice_length + subslice_length;
74 	topo.eu_stride = eu_stride;
75 
76 	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr),
77 			   &topo, sizeof(topo)))
78 		return -EFAULT;
79 
80 	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr + sizeof(topo)),
81 			   &sseu->slice_mask, slice_length))
82 		return -EFAULT;
83 
84 	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
85 					   sizeof(topo) + slice_length),
86 			   sseu->subslice_mask, subslice_length))
87 		return -EFAULT;
88 
89 	if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
90 					   sizeof(topo) +
91 					   slice_length + subslice_length),
92 			   sseu->eu_mask, eu_length))
93 		return -EFAULT;
94 
95 	return total_length;
96 }
97 
98 static int
99 query_engine_info(struct drm_i915_private *i915,
100 		  struct drm_i915_query_item *query_item)
101 {
102 	struct drm_i915_query_engine_info __user *query_ptr =
103 				u64_to_user_ptr(query_item->data_ptr);
104 	struct drm_i915_engine_info __user *info_ptr;
105 	struct drm_i915_query_engine_info query;
106 	struct drm_i915_engine_info info = { };
107 	struct intel_engine_cs *engine;
108 	enum intel_engine_id id;
109 	int len, ret;
110 
111 	if (query_item->flags)
112 		return -EINVAL;
113 
114 	len = sizeof(struct drm_i915_query_engine_info) +
115 	      RUNTIME_INFO(i915)->num_engines *
116 	      sizeof(struct drm_i915_engine_info);
117 
118 	ret = copy_query_item(&query, sizeof(query), len, query_item);
119 	if (ret != 0)
120 		return ret;
121 
122 	if (query.num_engines || query.rsvd[0] || query.rsvd[1] ||
123 	    query.rsvd[2])
124 		return -EINVAL;
125 
126 	info_ptr = &query_ptr->engines[0];
127 
128 	for_each_engine(engine, i915, id) {
129 		info.engine.engine_class = engine->uabi_class;
130 		info.engine.engine_instance = engine->instance;
131 		info.capabilities = engine->uabi_capabilities;
132 
133 		if (__copy_to_user(info_ptr, &info, sizeof(info)))
134 			return -EFAULT;
135 
136 		query.num_engines++;
137 		info_ptr++;
138 	}
139 
140 	if (__copy_to_user(query_ptr, &query, sizeof(query)))
141 		return -EFAULT;
142 
143 	return len;
144 }
145 
146 static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
147 					struct drm_i915_query_item *query_item) = {
148 	query_topology_info,
149 	query_engine_info,
150 };
151 
152 int i915_query_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
153 {
154 	struct drm_i915_private *dev_priv = to_i915(dev);
155 	struct drm_i915_query *args = data;
156 	struct drm_i915_query_item __user *user_item_ptr =
157 		u64_to_user_ptr(args->items_ptr);
158 	u32 i;
159 
160 	if (args->flags != 0)
161 		return -EINVAL;
162 
163 	for (i = 0; i < args->num_items; i++, user_item_ptr++) {
164 		struct drm_i915_query_item item;
165 		unsigned long func_idx;
166 		int ret;
167 
168 		if (copy_from_user(&item, user_item_ptr, sizeof(item)))
169 			return -EFAULT;
170 
171 		if (item.query_id == 0)
172 			return -EINVAL;
173 
174 		if (overflows_type(item.query_id - 1, unsigned long))
175 			return -EINVAL;
176 
177 		func_idx = item.query_id - 1;
178 
179 		ret = -EINVAL;
180 		if (func_idx < ARRAY_SIZE(i915_query_funcs)) {
181 			func_idx = array_index_nospec(func_idx,
182 						      ARRAY_SIZE(i915_query_funcs));
183 			ret = i915_query_funcs[func_idx](dev_priv, &item);
184 		}
185 
186 		/* Only write the length back to userspace if they differ. */
187 		if (ret != item.length && put_user(ret, &user_item_ptr->length))
188 			return -EFAULT;
189 	}
190 
191 	return 0;
192 }
193