1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * FPGA Region - Device Tree 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/of.h> 16 #include <linux/of_platform.h> 17 #include <linux/platform_device.h> 18 #include <linux/slab.h> 19 #include <linux/spinlock.h> 20 21 static const struct of_device_id fpga_region_of_match[] = { 22 { .compatible = "fpga-region", }, 23 {}, 24 }; 25 MODULE_DEVICE_TABLE(of, fpga_region_of_match); 26 27 /** 28 * of_fpga_region_find - find FPGA region 29 * @np: device node of FPGA Region 30 * 31 * Caller will need to put_device(®ion->dev) when done. 32 * 33 * Return: FPGA Region struct or NULL 34 */ 35 static struct fpga_region *of_fpga_region_find(struct device_node *np) 36 { 37 return fpga_region_class_find(NULL, np, device_match_of_node); 38 } 39 40 /** 41 * of_fpga_region_get_mgr - get reference for FPGA manager 42 * @np: device node of FPGA region 43 * 44 * Get FPGA Manager from "fpga-mgr" property or from ancestor region. 45 * 46 * Caller should call fpga_mgr_put() when done with manager. 47 * 48 * Return: fpga manager struct or IS_ERR() condition containing error code. 49 */ 50 static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np) 51 { 52 struct device_node *mgr_node; 53 struct fpga_manager *mgr; 54 55 of_node_get(np); 56 while (np) { 57 if (of_device_is_compatible(np, "fpga-region")) { 58 mgr_node = of_parse_phandle(np, "fpga-mgr", 0); 59 if (mgr_node) { 60 mgr = of_fpga_mgr_get(mgr_node); 61 of_node_put(mgr_node); 62 of_node_put(np); 63 return mgr; 64 } 65 } 66 np = of_get_next_parent(np); 67 } 68 of_node_put(np); 69 70 return ERR_PTR(-EINVAL); 71 } 72 73 /** 74 * of_fpga_region_get_bridges - create a list of bridges 75 * @region: FPGA region 76 * 77 * Create a list of bridges including the parent bridge and the bridges 78 * specified by "fpga-bridges" property. Note that the 79 * fpga_bridges_enable/disable/put functions are all fine with an empty list 80 * if that happens. 81 * 82 * Caller should call fpga_bridges_put(®ion->bridge_list) when 83 * done with the bridges. 84 * 85 * Return: 0 for success (even if there are no bridges specified) 86 * or -EBUSY if any of the bridges are in use. 87 */ 88 static int of_fpga_region_get_bridges(struct fpga_region *region) 89 { 90 struct device *dev = ®ion->dev; 91 struct device_node *region_np = dev->of_node; 92 struct fpga_image_info *info = region->info; 93 struct device_node *br, *np, *parent_br = NULL; 94 int i, ret; 95 96 /* If parent is a bridge, add to list */ 97 ret = of_fpga_bridge_get_to_list(region_np->parent, info, 98 ®ion->bridge_list); 99 100 /* -EBUSY means parent is a bridge that is under use. Give up. */ 101 if (ret == -EBUSY) 102 return ret; 103 104 /* Zero return code means parent was a bridge and was added to list. */ 105 if (!ret) 106 parent_br = region_np->parent; 107 108 /* If overlay has a list of bridges, use it. */ 109 br = of_parse_phandle(info->overlay, "fpga-bridges", 0); 110 if (br) { 111 of_node_put(br); 112 np = info->overlay; 113 } else { 114 np = region_np; 115 } 116 117 for (i = 0; ; i++) { 118 br = of_parse_phandle(np, "fpga-bridges", i); 119 if (!br) 120 break; 121 122 /* If parent bridge is in list, skip it. */ 123 if (br == parent_br) { 124 of_node_put(br); 125 continue; 126 } 127 128 /* If node is a bridge, get it and add to list */ 129 ret = of_fpga_bridge_get_to_list(br, info, 130 ®ion->bridge_list); 131 of_node_put(br); 132 133 /* If any of the bridges are in use, give up */ 134 if (ret == -EBUSY) { 135 fpga_bridges_put(®ion->bridge_list); 136 return -EBUSY; 137 } 138 } 139 140 return 0; 141 } 142 143 /** 144 * child_regions_with_firmware - Used to check the child region info. 145 * @overlay: device node of the overlay 146 * 147 * If the overlay adds child FPGA regions, they are not allowed to have 148 * firmware-name property. 149 * 150 * Return: 0 for OK or -EINVAL if child FPGA region adds firmware-name. 151 */ 152 static int child_regions_with_firmware(struct device_node *overlay) 153 { 154 struct device_node *child_region; 155 const char *child_firmware_name; 156 int ret = 0; 157 158 of_node_get(overlay); 159 160 child_region = of_find_matching_node(overlay, fpga_region_of_match); 161 while (child_region) { 162 if (!of_property_read_string(child_region, "firmware-name", 163 &child_firmware_name)) { 164 ret = -EINVAL; 165 break; 166 } 167 child_region = of_find_matching_node(child_region, 168 fpga_region_of_match); 169 } 170 171 of_node_put(child_region); 172 173 if (ret) 174 pr_err("firmware-name not allowed in child FPGA region: %pOF", 175 child_region); 176 177 return ret; 178 } 179 180 /** 181 * of_fpga_region_parse_ov - parse and check overlay applied to region 182 * 183 * @region: FPGA region 184 * @overlay: overlay applied to the FPGA region 185 * 186 * Given an overlay applied to an FPGA region, parse the FPGA image specific 187 * info in the overlay and do some checking. 188 * 189 * Return: 190 * NULL if overlay doesn't direct us to program the FPGA. 191 * fpga_image_info struct if there is an image to program. 192 * error code for invalid overlay. 193 */ 194 static struct fpga_image_info * 195 of_fpga_region_parse_ov(struct fpga_region *region, 196 struct device_node *overlay) 197 { 198 struct device *dev = ®ion->dev; 199 struct fpga_image_info *info; 200 const char *firmware_name; 201 int ret; 202 203 if (region->info) { 204 dev_err(dev, "Region already has overlay applied.\n"); 205 return ERR_PTR(-EINVAL); 206 } 207 208 /* 209 * Reject overlay if child FPGA Regions added in the overlay have 210 * firmware-name property (would mean that an FPGA region that has 211 * not been added to the live tree yet is doing FPGA programming). 212 */ 213 ret = child_regions_with_firmware(overlay); 214 if (ret) 215 return ERR_PTR(ret); 216 217 info = fpga_image_info_alloc(dev); 218 if (!info) 219 return ERR_PTR(-ENOMEM); 220 221 info->overlay = overlay; 222 223 /* Read FPGA region properties from the overlay */ 224 if (of_property_read_bool(overlay, "partial-fpga-config")) 225 info->flags |= FPGA_MGR_PARTIAL_RECONFIG; 226 227 if (of_property_read_bool(overlay, "external-fpga-config")) 228 info->flags |= FPGA_MGR_EXTERNAL_CONFIG; 229 230 if (of_property_read_bool(overlay, "encrypted-fpga-config")) 231 info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM; 232 233 if (!of_property_read_string(overlay, "firmware-name", 234 &firmware_name)) { 235 info->firmware_name = devm_kstrdup(dev, firmware_name, 236 GFP_KERNEL); 237 if (!info->firmware_name) 238 return ERR_PTR(-ENOMEM); 239 } 240 241 of_property_read_u32(overlay, "region-unfreeze-timeout-us", 242 &info->enable_timeout_us); 243 244 of_property_read_u32(overlay, "region-freeze-timeout-us", 245 &info->disable_timeout_us); 246 247 of_property_read_u32(overlay, "config-complete-timeout-us", 248 &info->config_complete_timeout_us); 249 250 /* If overlay is not programming the FPGA, don't need FPGA image info */ 251 if (!info->firmware_name) { 252 ret = 0; 253 goto ret_no_info; 254 } 255 256 /* 257 * If overlay informs us FPGA was externally programmed, specifying 258 * firmware here would be ambiguous. 259 */ 260 if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) { 261 dev_err(dev, "error: specified firmware and external-fpga-config"); 262 ret = -EINVAL; 263 goto ret_no_info; 264 } 265 266 return info; 267 ret_no_info: 268 fpga_image_info_free(info); 269 return ERR_PTR(ret); 270 } 271 272 /** 273 * of_fpga_region_notify_pre_apply - pre-apply overlay notification 274 * 275 * @region: FPGA region that the overlay was applied to 276 * @nd: overlay notification data 277 * 278 * Called when an overlay targeted to an FPGA Region is about to be applied. 279 * Parses the overlay for properties that influence how the FPGA will be 280 * programmed and does some checking. If the checks pass, programs the FPGA. 281 * If the checks fail, overlay is rejected and does not get added to the 282 * live tree. 283 * 284 * Return: 0 for success or negative error code for failure. 285 */ 286 static int of_fpga_region_notify_pre_apply(struct fpga_region *region, 287 struct of_overlay_notify_data *nd) 288 { 289 struct device *dev = ®ion->dev; 290 struct fpga_image_info *info; 291 int ret; 292 293 info = of_fpga_region_parse_ov(region, nd->overlay); 294 if (IS_ERR(info)) 295 return PTR_ERR(info); 296 297 /* If overlay doesn't program the FPGA, accept it anyway. */ 298 if (!info) 299 return 0; 300 301 if (region->info) { 302 dev_err(dev, "Region already has overlay applied.\n"); 303 return -EINVAL; 304 } 305 306 region->info = info; 307 ret = fpga_region_program_fpga(region); 308 if (ret) { 309 /* error; reject overlay */ 310 fpga_image_info_free(info); 311 region->info = NULL; 312 } 313 314 return ret; 315 } 316 317 /** 318 * of_fpga_region_notify_post_remove - post-remove overlay notification 319 * 320 * @region: FPGA region that was targeted by the overlay that was removed 321 * @nd: overlay notification data 322 * 323 * Called after an overlay has been removed if the overlay's target was a 324 * FPGA region. 325 */ 326 static void of_fpga_region_notify_post_remove(struct fpga_region *region, 327 struct of_overlay_notify_data *nd) 328 { 329 fpga_bridges_disable(®ion->bridge_list); 330 fpga_bridges_put(®ion->bridge_list); 331 fpga_image_info_free(region->info); 332 region->info = NULL; 333 } 334 335 /** 336 * of_fpga_region_notify - reconfig notifier for dynamic DT changes 337 * @nb: notifier block 338 * @action: notifier action 339 * @arg: reconfig data 340 * 341 * This notifier handles programming an FPGA when a "firmware-name" property is 342 * added to an fpga-region. 343 * 344 * Return: NOTIFY_OK or error if FPGA programming fails. 345 */ 346 static int of_fpga_region_notify(struct notifier_block *nb, 347 unsigned long action, void *arg) 348 { 349 struct of_overlay_notify_data *nd = arg; 350 struct fpga_region *region; 351 int ret; 352 353 switch (action) { 354 case OF_OVERLAY_PRE_APPLY: 355 pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__); 356 break; 357 case OF_OVERLAY_POST_APPLY: 358 pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__); 359 return NOTIFY_OK; /* not for us */ 360 case OF_OVERLAY_PRE_REMOVE: 361 pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__); 362 return NOTIFY_OK; /* not for us */ 363 case OF_OVERLAY_POST_REMOVE: 364 pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__); 365 break; 366 default: /* should not happen */ 367 return NOTIFY_OK; 368 } 369 370 region = of_fpga_region_find(nd->target); 371 if (!region) 372 return NOTIFY_OK; 373 374 ret = 0; 375 switch (action) { 376 case OF_OVERLAY_PRE_APPLY: 377 ret = of_fpga_region_notify_pre_apply(region, nd); 378 break; 379 380 case OF_OVERLAY_POST_REMOVE: 381 of_fpga_region_notify_post_remove(region, nd); 382 break; 383 } 384 385 put_device(®ion->dev); 386 387 if (ret) 388 return notifier_from_errno(ret); 389 390 return NOTIFY_OK; 391 } 392 393 static struct notifier_block fpga_region_of_nb = { 394 .notifier_call = of_fpga_region_notify, 395 }; 396 397 static int of_fpga_region_probe(struct platform_device *pdev) 398 { 399 struct device *dev = &pdev->dev; 400 struct device_node *np = dev->of_node; 401 struct fpga_region *region; 402 struct fpga_manager *mgr; 403 int ret; 404 405 /* Find the FPGA mgr specified by region or parent region. */ 406 mgr = of_fpga_region_get_mgr(np); 407 if (IS_ERR(mgr)) 408 return -EPROBE_DEFER; 409 410 region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges); 411 if (IS_ERR(region)) { 412 ret = PTR_ERR(region); 413 goto eprobe_mgr_put; 414 } 415 416 of_platform_populate(np, fpga_region_of_match, NULL, ®ion->dev); 417 platform_set_drvdata(pdev, region); 418 419 dev_info(dev, "FPGA Region probed\n"); 420 421 return 0; 422 423 eprobe_mgr_put: 424 fpga_mgr_put(mgr); 425 return ret; 426 } 427 428 static int of_fpga_region_remove(struct platform_device *pdev) 429 { 430 struct fpga_region *region = platform_get_drvdata(pdev); 431 struct fpga_manager *mgr = region->mgr; 432 433 fpga_region_unregister(region); 434 fpga_mgr_put(mgr); 435 436 return 0; 437 } 438 439 static struct platform_driver of_fpga_region_driver = { 440 .probe = of_fpga_region_probe, 441 .remove = of_fpga_region_remove, 442 .driver = { 443 .name = "of-fpga-region", 444 .of_match_table = of_match_ptr(fpga_region_of_match), 445 }, 446 }; 447 448 /** 449 * of_fpga_region_init - init function for fpga_region class 450 * Creates the fpga_region class and registers a reconfig notifier. 451 * 452 * Return: 0 on success, negative error code otherwise. 453 */ 454 static int __init of_fpga_region_init(void) 455 { 456 int ret; 457 458 ret = of_overlay_notifier_register(&fpga_region_of_nb); 459 if (ret) 460 return ret; 461 462 ret = platform_driver_register(&of_fpga_region_driver); 463 if (ret) 464 goto err_plat; 465 466 return 0; 467 468 err_plat: 469 of_overlay_notifier_unregister(&fpga_region_of_nb); 470 return ret; 471 } 472 473 static void __exit of_fpga_region_exit(void) 474 { 475 platform_driver_unregister(&of_fpga_region_driver); 476 of_overlay_notifier_unregister(&fpga_region_of_nb); 477 } 478 479 subsys_initcall(of_fpga_region_init); 480 module_exit(of_fpga_region_exit); 481 482 MODULE_DESCRIPTION("FPGA Region"); 483 MODULE_AUTHOR("Alan Tull <atull@kernel.org>"); 484 MODULE_LICENSE("GPL v2"); 485