Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * FPGA Region - Support for FPGA programming under Linux
4 *
5 * Copyright (C) 2013-2016 Altera Corporation
6 * Copyright (C) 2017 Intel Corporation
7 */
8#include <linux/fpga/fpga-bridge.h>
9#include <linux/fpga/fpga-mgr.h>
10#include <linux/fpga/fpga-region.h>
11#include <linux/idr.h>
12#include <linux/kernel.h>
13#include <linux/list.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/spinlock.h>
17
18static DEFINE_IDA(fpga_region_ida);
19static struct class *fpga_region_class;
20
21struct fpga_region *
22fpga_region_class_find(struct device *start, const void *data,
23 int (*match)(struct device *, const void *))
24{
25 struct device *dev;
26
27 dev = class_find_device(fpga_region_class, start, data, match);
28 if (!dev)
29 return NULL;
30
31 return to_fpga_region(dev);
32}
33EXPORT_SYMBOL_GPL(fpga_region_class_find);
34
35/**
36 * fpga_region_get - get an exclusive reference to an fpga region
37 * @region: FPGA Region struct
38 *
39 * Caller should call fpga_region_put() when done with region.
40 *
41 * Return fpga_region struct if successful.
42 * Return -EBUSY if someone already has a reference to the region.
43 * Return -ENODEV if @np is not an FPGA Region.
44 */
45static struct fpga_region *fpga_region_get(struct fpga_region *region)
46{
47 struct device *dev = ®ion->dev;
48
49 if (!mutex_trylock(®ion->mutex)) {
50 dev_dbg(dev, "%s: FPGA Region already in use\n", __func__);
51 return ERR_PTR(-EBUSY);
52 }
53
54 get_device(dev);
55 if (!try_module_get(dev->parent->driver->owner)) {
56 put_device(dev);
57 mutex_unlock(®ion->mutex);
58 return ERR_PTR(-ENODEV);
59 }
60
61 dev_dbg(dev, "get\n");
62
63 return region;
64}
65
66/**
67 * fpga_region_put - release a reference to a region
68 *
69 * @region: FPGA region
70 */
71static void fpga_region_put(struct fpga_region *region)
72{
73 struct device *dev = ®ion->dev;
74
75 dev_dbg(dev, "put\n");
76
77 module_put(dev->parent->driver->owner);
78 put_device(dev);
79 mutex_unlock(®ion->mutex);
80}
81
82/**
83 * fpga_region_program_fpga - program FPGA
84 *
85 * @region: FPGA region
86 *
87 * Program an FPGA using fpga image info (region->info).
88 * If the region has a get_bridges function, the exclusive reference for the
89 * bridges will be held if programming succeeds. This is intended to prevent
90 * reprogramming the region until the caller considers it safe to do so.
91 * The caller will need to call fpga_bridges_put() before attempting to
92 * reprogram the region.
93 *
94 * Return 0 for success or negative error code.
95 */
96int fpga_region_program_fpga(struct fpga_region *region)
97{
98 struct device *dev = ®ion->dev;
99 struct fpga_image_info *info = region->info;
100 int ret;
101
102 region = fpga_region_get(region);
103 if (IS_ERR(region)) {
104 dev_err(dev, "failed to get FPGA region\n");
105 return PTR_ERR(region);
106 }
107
108 ret = fpga_mgr_lock(region->mgr);
109 if (ret) {
110 dev_err(dev, "FPGA manager is busy\n");
111 goto err_put_region;
112 }
113
114 /*
115 * In some cases, we already have a list of bridges in the
116 * fpga region struct. Or we don't have any bridges.
117 */
118 if (region->get_bridges) {
119 ret = region->get_bridges(region);
120 if (ret) {
121 dev_err(dev, "failed to get fpga region bridges\n");
122 goto err_unlock_mgr;
123 }
124 }
125
126 ret = fpga_bridges_disable(®ion->bridge_list);
127 if (ret) {
128 dev_err(dev, "failed to disable bridges\n");
129 goto err_put_br;
130 }
131
132 ret = fpga_mgr_load(region->mgr, info);
133 if (ret) {
134 dev_err(dev, "failed to load FPGA image\n");
135 goto err_put_br;
136 }
137
138 ret = fpga_bridges_enable(®ion->bridge_list);
139 if (ret) {
140 dev_err(dev, "failed to enable region bridges\n");
141 goto err_put_br;
142 }
143
144 fpga_mgr_unlock(region->mgr);
145 fpga_region_put(region);
146
147 return 0;
148
149err_put_br:
150 if (region->get_bridges)
151 fpga_bridges_put(®ion->bridge_list);
152err_unlock_mgr:
153 fpga_mgr_unlock(region->mgr);
154err_put_region:
155 fpga_region_put(region);
156
157 return ret;
158}
159EXPORT_SYMBOL_GPL(fpga_region_program_fpga);
160
161static ssize_t compat_id_show(struct device *dev,
162 struct device_attribute *attr, char *buf)
163{
164 struct fpga_region *region = to_fpga_region(dev);
165
166 if (!region->compat_id)
167 return -ENOENT;
168
169 return sprintf(buf, "%016llx%016llx\n",
170 (unsigned long long)region->compat_id->id_h,
171 (unsigned long long)region->compat_id->id_l);
172}
173
174static DEVICE_ATTR_RO(compat_id);
175
176static struct attribute *fpga_region_attrs[] = {
177 &dev_attr_compat_id.attr,
178 NULL,
179};
180ATTRIBUTE_GROUPS(fpga_region);
181
182/**
183 * fpga_region_register_full - create and register an FPGA Region device
184 * @parent: device parent
185 * @info: parameters for FPGA Region
186 *
187 * Return: struct fpga_region or ERR_PTR()
188 */
189struct fpga_region *
190fpga_region_register_full(struct device *parent, const struct fpga_region_info *info)
191{
192 struct fpga_region *region;
193 int id, ret = 0;
194
195 if (!info) {
196 dev_err(parent,
197 "Attempt to register without required info structure\n");
198 return ERR_PTR(-EINVAL);
199 }
200
201 region = kzalloc(sizeof(*region), GFP_KERNEL);
202 if (!region)
203 return ERR_PTR(-ENOMEM);
204
205 id = ida_alloc(&fpga_region_ida, GFP_KERNEL);
206 if (id < 0) {
207 ret = id;
208 goto err_free;
209 }
210
211 region->mgr = info->mgr;
212 region->compat_id = info->compat_id;
213 region->priv = info->priv;
214 region->get_bridges = info->get_bridges;
215
216 mutex_init(®ion->mutex);
217 INIT_LIST_HEAD(®ion->bridge_list);
218
219 region->dev.class = fpga_region_class;
220 region->dev.parent = parent;
221 region->dev.of_node = parent->of_node;
222 region->dev.id = id;
223
224 ret = dev_set_name(®ion->dev, "region%d", id);
225 if (ret)
226 goto err_remove;
227
228 ret = device_register(®ion->dev);
229 if (ret) {
230 put_device(®ion->dev);
231 return ERR_PTR(ret);
232 }
233
234 return region;
235
236err_remove:
237 ida_free(&fpga_region_ida, id);
238err_free:
239 kfree(region);
240
241 return ERR_PTR(ret);
242}
243EXPORT_SYMBOL_GPL(fpga_region_register_full);
244
245/**
246 * fpga_region_register - create and register an FPGA Region device
247 * @parent: device parent
248 * @mgr: manager that programs this region
249 * @get_bridges: optional function to get bridges to a list
250 *
251 * This simple version of the register function should be sufficient for most users.
252 * The fpga_region_register_full() function is available for users that need to
253 * pass additional, optional parameters.
254 *
255 * Return: struct fpga_region or ERR_PTR()
256 */
257struct fpga_region *
258fpga_region_register(struct device *parent, struct fpga_manager *mgr,
259 int (*get_bridges)(struct fpga_region *))
260{
261 struct fpga_region_info info = { 0 };
262
263 info.mgr = mgr;
264 info.get_bridges = get_bridges;
265
266 return fpga_region_register_full(parent, &info);
267}
268EXPORT_SYMBOL_GPL(fpga_region_register);
269
270/**
271 * fpga_region_unregister - unregister an FPGA region
272 * @region: FPGA region
273 *
274 * This function is intended for use in an FPGA region driver's remove function.
275 */
276void fpga_region_unregister(struct fpga_region *region)
277{
278 device_unregister(®ion->dev);
279}
280EXPORT_SYMBOL_GPL(fpga_region_unregister);
281
282static void fpga_region_dev_release(struct device *dev)
283{
284 struct fpga_region *region = to_fpga_region(dev);
285
286 ida_free(&fpga_region_ida, region->dev.id);
287 kfree(region);
288}
289
290/**
291 * fpga_region_init - init function for fpga_region class
292 * Creates the fpga_region class and registers a reconfig notifier.
293 */
294static int __init fpga_region_init(void)
295{
296 fpga_region_class = class_create(THIS_MODULE, "fpga_region");
297 if (IS_ERR(fpga_region_class))
298 return PTR_ERR(fpga_region_class);
299
300 fpga_region_class->dev_groups = fpga_region_groups;
301 fpga_region_class->dev_release = fpga_region_dev_release;
302
303 return 0;
304}
305
306static void __exit fpga_region_exit(void)
307{
308 class_destroy(fpga_region_class);
309 ida_destroy(&fpga_region_ida);
310}
311
312subsys_initcall(fpga_region_init);
313module_exit(fpga_region_exit);
314
315MODULE_DESCRIPTION("FPGA Region");
316MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
317MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * FPGA Region - Support for FPGA programming under Linux
4 *
5 * Copyright (C) 2013-2016 Altera Corporation
6 * Copyright (C) 2017 Intel Corporation
7 */
8#include <linux/fpga/fpga-bridge.h>
9#include <linux/fpga/fpga-mgr.h>
10#include <linux/fpga/fpga-region.h>
11#include <linux/idr.h>
12#include <linux/kernel.h>
13#include <linux/list.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/spinlock.h>
17
18static DEFINE_IDA(fpga_region_ida);
19static const struct class fpga_region_class;
20
21struct fpga_region *
22fpga_region_class_find(struct device *start, const void *data,
23 int (*match)(struct device *, const void *))
24{
25 struct device *dev;
26
27 dev = class_find_device(&fpga_region_class, start, data, match);
28 if (!dev)
29 return NULL;
30
31 return to_fpga_region(dev);
32}
33EXPORT_SYMBOL_GPL(fpga_region_class_find);
34
35/**
36 * fpga_region_get - get an exclusive reference to an fpga region
37 * @region: FPGA Region struct
38 *
39 * Caller should call fpga_region_put() when done with region.
40 *
41 * Return:
42 * * fpga_region struct if successful.
43 * * -EBUSY if someone already has a reference to the region.
44 * * -ENODEV if can't take parent driver module refcount.
45 */
46static struct fpga_region *fpga_region_get(struct fpga_region *region)
47{
48 struct device *dev = ®ion->dev;
49
50 if (!mutex_trylock(®ion->mutex)) {
51 dev_dbg(dev, "%s: FPGA Region already in use\n", __func__);
52 return ERR_PTR(-EBUSY);
53 }
54
55 get_device(dev);
56 if (!try_module_get(dev->parent->driver->owner)) {
57 put_device(dev);
58 mutex_unlock(®ion->mutex);
59 return ERR_PTR(-ENODEV);
60 }
61
62 dev_dbg(dev, "get\n");
63
64 return region;
65}
66
67/**
68 * fpga_region_put - release a reference to a region
69 *
70 * @region: FPGA region
71 */
72static void fpga_region_put(struct fpga_region *region)
73{
74 struct device *dev = ®ion->dev;
75
76 dev_dbg(dev, "put\n");
77
78 module_put(dev->parent->driver->owner);
79 put_device(dev);
80 mutex_unlock(®ion->mutex);
81}
82
83/**
84 * fpga_region_program_fpga - program FPGA
85 *
86 * @region: FPGA region
87 *
88 * Program an FPGA using fpga image info (region->info).
89 * If the region has a get_bridges function, the exclusive reference for the
90 * bridges will be held if programming succeeds. This is intended to prevent
91 * reprogramming the region until the caller considers it safe to do so.
92 * The caller will need to call fpga_bridges_put() before attempting to
93 * reprogram the region.
94 *
95 * Return: 0 for success or negative error code.
96 */
97int fpga_region_program_fpga(struct fpga_region *region)
98{
99 struct device *dev = ®ion->dev;
100 struct fpga_image_info *info = region->info;
101 int ret;
102
103 region = fpga_region_get(region);
104 if (IS_ERR(region)) {
105 dev_err(dev, "failed to get FPGA region\n");
106 return PTR_ERR(region);
107 }
108
109 ret = fpga_mgr_lock(region->mgr);
110 if (ret) {
111 dev_err(dev, "FPGA manager is busy\n");
112 goto err_put_region;
113 }
114
115 /*
116 * In some cases, we already have a list of bridges in the
117 * fpga region struct. Or we don't have any bridges.
118 */
119 if (region->get_bridges) {
120 ret = region->get_bridges(region);
121 if (ret) {
122 dev_err(dev, "failed to get fpga region bridges\n");
123 goto err_unlock_mgr;
124 }
125 }
126
127 ret = fpga_bridges_disable(®ion->bridge_list);
128 if (ret) {
129 dev_err(dev, "failed to disable bridges\n");
130 goto err_put_br;
131 }
132
133 ret = fpga_mgr_load(region->mgr, info);
134 if (ret) {
135 dev_err(dev, "failed to load FPGA image\n");
136 goto err_put_br;
137 }
138
139 ret = fpga_bridges_enable(®ion->bridge_list);
140 if (ret) {
141 dev_err(dev, "failed to enable region bridges\n");
142 goto err_put_br;
143 }
144
145 fpga_mgr_unlock(region->mgr);
146 fpga_region_put(region);
147
148 return 0;
149
150err_put_br:
151 if (region->get_bridges)
152 fpga_bridges_put(®ion->bridge_list);
153err_unlock_mgr:
154 fpga_mgr_unlock(region->mgr);
155err_put_region:
156 fpga_region_put(region);
157
158 return ret;
159}
160EXPORT_SYMBOL_GPL(fpga_region_program_fpga);
161
162static ssize_t compat_id_show(struct device *dev,
163 struct device_attribute *attr, char *buf)
164{
165 struct fpga_region *region = to_fpga_region(dev);
166
167 if (!region->compat_id)
168 return -ENOENT;
169
170 return sprintf(buf, "%016llx%016llx\n",
171 (unsigned long long)region->compat_id->id_h,
172 (unsigned long long)region->compat_id->id_l);
173}
174
175static DEVICE_ATTR_RO(compat_id);
176
177static struct attribute *fpga_region_attrs[] = {
178 &dev_attr_compat_id.attr,
179 NULL,
180};
181ATTRIBUTE_GROUPS(fpga_region);
182
183/**
184 * fpga_region_register_full - create and register an FPGA Region device
185 * @parent: device parent
186 * @info: parameters for FPGA Region
187 *
188 * Return: struct fpga_region or ERR_PTR()
189 */
190struct fpga_region *
191fpga_region_register_full(struct device *parent, const struct fpga_region_info *info)
192{
193 struct fpga_region *region;
194 int id, ret = 0;
195
196 if (!info) {
197 dev_err(parent,
198 "Attempt to register without required info structure\n");
199 return ERR_PTR(-EINVAL);
200 }
201
202 region = kzalloc(sizeof(*region), GFP_KERNEL);
203 if (!region)
204 return ERR_PTR(-ENOMEM);
205
206 id = ida_alloc(&fpga_region_ida, GFP_KERNEL);
207 if (id < 0) {
208 ret = id;
209 goto err_free;
210 }
211
212 region->mgr = info->mgr;
213 region->compat_id = info->compat_id;
214 region->priv = info->priv;
215 region->get_bridges = info->get_bridges;
216
217 mutex_init(®ion->mutex);
218 INIT_LIST_HEAD(®ion->bridge_list);
219
220 region->dev.class = &fpga_region_class;
221 region->dev.parent = parent;
222 region->dev.of_node = parent->of_node;
223 region->dev.id = id;
224
225 ret = dev_set_name(®ion->dev, "region%d", id);
226 if (ret)
227 goto err_remove;
228
229 ret = device_register(®ion->dev);
230 if (ret) {
231 put_device(®ion->dev);
232 return ERR_PTR(ret);
233 }
234
235 return region;
236
237err_remove:
238 ida_free(&fpga_region_ida, id);
239err_free:
240 kfree(region);
241
242 return ERR_PTR(ret);
243}
244EXPORT_SYMBOL_GPL(fpga_region_register_full);
245
246/**
247 * fpga_region_register - create and register an FPGA Region device
248 * @parent: device parent
249 * @mgr: manager that programs this region
250 * @get_bridges: optional function to get bridges to a list
251 *
252 * This simple version of the register function should be sufficient for most users.
253 * The fpga_region_register_full() function is available for users that need to
254 * pass additional, optional parameters.
255 *
256 * Return: struct fpga_region or ERR_PTR()
257 */
258struct fpga_region *
259fpga_region_register(struct device *parent, struct fpga_manager *mgr,
260 int (*get_bridges)(struct fpga_region *))
261{
262 struct fpga_region_info info = { 0 };
263
264 info.mgr = mgr;
265 info.get_bridges = get_bridges;
266
267 return fpga_region_register_full(parent, &info);
268}
269EXPORT_SYMBOL_GPL(fpga_region_register);
270
271/**
272 * fpga_region_unregister - unregister an FPGA region
273 * @region: FPGA region
274 *
275 * This function is intended for use in an FPGA region driver's remove function.
276 */
277void fpga_region_unregister(struct fpga_region *region)
278{
279 device_unregister(®ion->dev);
280}
281EXPORT_SYMBOL_GPL(fpga_region_unregister);
282
283static void fpga_region_dev_release(struct device *dev)
284{
285 struct fpga_region *region = to_fpga_region(dev);
286
287 ida_free(&fpga_region_ida, region->dev.id);
288 kfree(region);
289}
290
291static const struct class fpga_region_class = {
292 .name = "fpga_region",
293 .dev_groups = fpga_region_groups,
294 .dev_release = fpga_region_dev_release,
295};
296
297/**
298 * fpga_region_init - creates the fpga_region class.
299 *
300 * Return: 0 on success or ERR_PTR() on error.
301 */
302static int __init fpga_region_init(void)
303{
304 return class_register(&fpga_region_class);
305}
306
307static void __exit fpga_region_exit(void)
308{
309 class_unregister(&fpga_region_class);
310 ida_destroy(&fpga_region_ida);
311}
312
313subsys_initcall(fpga_region_init);
314module_exit(fpga_region_exit);
315
316MODULE_DESCRIPTION("FPGA Region");
317MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
318MODULE_LICENSE("GPL v2");