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 18 static DEFINE_IDA(fpga_region_ida); 19 static struct class *fpga_region_class; 20 21 struct fpga_region *fpga_region_class_find( 22 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 } 33 EXPORT_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 */ 45 static 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 */ 71 static 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 */ 96 int 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; 148 149 err_put_br: 150 if (region->get_bridges) 151 fpga_bridges_put(®ion->bridge_list); 152 err_unlock_mgr: 153 fpga_mgr_unlock(region->mgr); 154 err_put_region: 155 fpga_region_put(region); 156 157 return ret; 158 } 159 EXPORT_SYMBOL_GPL(fpga_region_program_fpga); 160 161 static 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 } 173 174 static DEVICE_ATTR_RO(compat_id); 175 176 static struct attribute *fpga_region_attrs[] = { 177 &dev_attr_compat_id.attr, 178 NULL, 179 }; 180 ATTRIBUTE_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 */ 189 struct fpga_region * 190 fpga_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_simple_get(&fpga_region_ida, 0, 0, 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; 235 236 err_remove: 237 ida_simple_remove(&fpga_region_ida, id); 238 err_free: 239 kfree(region); 240 241 return ERR_PTR(ret); 242 } 243 EXPORT_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 */ 257 struct fpga_region * 258 fpga_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 } 268 EXPORT_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 */ 276 void fpga_region_unregister(struct fpga_region *region) 277 { 278 device_unregister(®ion->dev); 279 } 280 EXPORT_SYMBOL_GPL(fpga_region_unregister); 281 282 static void fpga_region_dev_release(struct device *dev) 283 { 284 struct fpga_region *region = to_fpga_region(dev); 285 286 ida_simple_remove(&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 */ 294 static 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 } 305 306 static void __exit fpga_region_exit(void) 307 { 308 class_destroy(fpga_region_class); 309 ida_destroy(&fpga_region_ida); 310 } 311 312 subsys_initcall(fpga_region_init); 313 module_exit(fpga_region_exit); 314 315 MODULE_DESCRIPTION("FPGA Region"); 316 MODULE_AUTHOR("Alan Tull <atull@kernel.org>"); 317 MODULE_LICENSE("GPL v2"); 318