1 /* 2 * Copyright (C) 2014-2017 Broadcom 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/init.h> 15 #include <linux/types.h> 16 #include <linux/module.h> 17 #include <linux/platform_device.h> 18 #include <linux/interrupt.h> 19 #include <linux/sysfs.h> 20 #include <linux/io.h> 21 #include <linux/string.h> 22 #include <linux/device.h> 23 #include <linux/list.h> 24 #include <linux/of.h> 25 #include <linux/bitops.h> 26 #include <linux/pm.h> 27 #include <linux/kernel.h> 28 #include <linux/kdebug.h> 29 #include <linux/notifier.h> 30 31 #ifdef CONFIG_MIPS 32 #include <asm/traps.h> 33 #endif 34 35 #define ARB_ERR_CAP_CLEAR (1 << 0) 36 #define ARB_ERR_CAP_STATUS_TIMEOUT (1 << 12) 37 #define ARB_ERR_CAP_STATUS_TEA (1 << 11) 38 #define ARB_ERR_CAP_STATUS_WRITE (1 << 1) 39 #define ARB_ERR_CAP_STATUS_VALID (1 << 0) 40 41 enum { 42 ARB_TIMER, 43 ARB_ERR_CAP_CLR, 44 ARB_ERR_CAP_HI_ADDR, 45 ARB_ERR_CAP_ADDR, 46 ARB_ERR_CAP_STATUS, 47 ARB_ERR_CAP_MASTER, 48 }; 49 50 static const int gisb_offsets_bcm7038[] = { 51 [ARB_TIMER] = 0x00c, 52 [ARB_ERR_CAP_CLR] = 0x0c4, 53 [ARB_ERR_CAP_HI_ADDR] = -1, 54 [ARB_ERR_CAP_ADDR] = 0x0c8, 55 [ARB_ERR_CAP_STATUS] = 0x0d0, 56 [ARB_ERR_CAP_MASTER] = -1, 57 }; 58 59 static const int gisb_offsets_bcm7278[] = { 60 [ARB_TIMER] = 0x008, 61 [ARB_ERR_CAP_CLR] = 0x7f8, 62 [ARB_ERR_CAP_HI_ADDR] = -1, 63 [ARB_ERR_CAP_ADDR] = 0x7e0, 64 [ARB_ERR_CAP_STATUS] = 0x7f0, 65 [ARB_ERR_CAP_MASTER] = 0x7f4, 66 }; 67 68 static const int gisb_offsets_bcm7400[] = { 69 [ARB_TIMER] = 0x00c, 70 [ARB_ERR_CAP_CLR] = 0x0c8, 71 [ARB_ERR_CAP_HI_ADDR] = -1, 72 [ARB_ERR_CAP_ADDR] = 0x0cc, 73 [ARB_ERR_CAP_STATUS] = 0x0d4, 74 [ARB_ERR_CAP_MASTER] = 0x0d8, 75 }; 76 77 static const int gisb_offsets_bcm7435[] = { 78 [ARB_TIMER] = 0x00c, 79 [ARB_ERR_CAP_CLR] = 0x168, 80 [ARB_ERR_CAP_HI_ADDR] = -1, 81 [ARB_ERR_CAP_ADDR] = 0x16c, 82 [ARB_ERR_CAP_STATUS] = 0x174, 83 [ARB_ERR_CAP_MASTER] = 0x178, 84 }; 85 86 static const int gisb_offsets_bcm7445[] = { 87 [ARB_TIMER] = 0x008, 88 [ARB_ERR_CAP_CLR] = 0x7e4, 89 [ARB_ERR_CAP_HI_ADDR] = 0x7e8, 90 [ARB_ERR_CAP_ADDR] = 0x7ec, 91 [ARB_ERR_CAP_STATUS] = 0x7f4, 92 [ARB_ERR_CAP_MASTER] = 0x7f8, 93 }; 94 95 struct brcmstb_gisb_arb_device { 96 void __iomem *base; 97 const int *gisb_offsets; 98 bool big_endian; 99 struct mutex lock; 100 struct list_head next; 101 u32 valid_mask; 102 const char *master_names[sizeof(u32) * BITS_PER_BYTE]; 103 u32 saved_timeout; 104 }; 105 106 static LIST_HEAD(brcmstb_gisb_arb_device_list); 107 108 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg) 109 { 110 int offset = gdev->gisb_offsets[reg]; 111 112 if (offset < 0) { 113 /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */ 114 if (reg == ARB_ERR_CAP_MASTER) 115 return 1; 116 else 117 return 0; 118 } 119 120 if (gdev->big_endian) 121 return ioread32be(gdev->base + offset); 122 else 123 return ioread32(gdev->base + offset); 124 } 125 126 static u64 gisb_read_address(struct brcmstb_gisb_arb_device *gdev) 127 { 128 u64 value; 129 130 value = gisb_read(gdev, ARB_ERR_CAP_ADDR); 131 value |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32; 132 133 return value; 134 } 135 136 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg) 137 { 138 int offset = gdev->gisb_offsets[reg]; 139 140 if (offset == -1) 141 return; 142 143 if (gdev->big_endian) 144 iowrite32be(val, gdev->base + offset); 145 else 146 iowrite32(val, gdev->base + offset); 147 } 148 149 static ssize_t gisb_arb_get_timeout(struct device *dev, 150 struct device_attribute *attr, 151 char *buf) 152 { 153 struct platform_device *pdev = to_platform_device(dev); 154 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev); 155 u32 timeout; 156 157 mutex_lock(&gdev->lock); 158 timeout = gisb_read(gdev, ARB_TIMER); 159 mutex_unlock(&gdev->lock); 160 161 return sprintf(buf, "%d", timeout); 162 } 163 164 static ssize_t gisb_arb_set_timeout(struct device *dev, 165 struct device_attribute *attr, 166 const char *buf, size_t count) 167 { 168 struct platform_device *pdev = to_platform_device(dev); 169 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev); 170 int val, ret; 171 172 ret = kstrtoint(buf, 10, &val); 173 if (ret < 0) 174 return ret; 175 176 if (val == 0 || val >= 0xffffffff) 177 return -EINVAL; 178 179 mutex_lock(&gdev->lock); 180 gisb_write(gdev, val, ARB_TIMER); 181 mutex_unlock(&gdev->lock); 182 183 return count; 184 } 185 186 static const char * 187 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev, 188 u32 masters) 189 { 190 u32 mask = gdev->valid_mask & masters; 191 192 if (hweight_long(mask) != 1) 193 return NULL; 194 195 return gdev->master_names[ffs(mask) - 1]; 196 } 197 198 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev, 199 const char *reason) 200 { 201 u32 cap_status; 202 u64 arb_addr; 203 u32 master; 204 const char *m_name; 205 char m_fmt[11]; 206 207 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS); 208 209 /* Invalid captured address, bail out */ 210 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) 211 return 1; 212 213 /* Read the address and master */ 214 arb_addr = gisb_read_address(gdev); 215 master = gisb_read(gdev, ARB_ERR_CAP_MASTER); 216 217 m_name = brcmstb_gisb_master_to_str(gdev, master); 218 if (!m_name) { 219 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master); 220 m_name = m_fmt; 221 } 222 223 pr_crit("%s: %s at 0x%llx [%c %s], core: %s\n", 224 __func__, reason, arb_addr, 225 cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R', 226 cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "", 227 m_name); 228 229 /* clear the GISB error */ 230 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR); 231 232 return 0; 233 } 234 235 #ifdef CONFIG_MIPS 236 static int brcmstb_bus_error_handler(struct pt_regs *regs, int is_fixup) 237 { 238 int ret = 0; 239 struct brcmstb_gisb_arb_device *gdev; 240 u32 cap_status; 241 242 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) { 243 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS); 244 245 /* Invalid captured address, bail out */ 246 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) { 247 is_fixup = 1; 248 goto out; 249 } 250 251 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error"); 252 } 253 out: 254 return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL; 255 } 256 #endif 257 258 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id) 259 { 260 brcmstb_gisb_arb_decode_addr(dev_id, "timeout"); 261 262 return IRQ_HANDLED; 263 } 264 265 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id) 266 { 267 brcmstb_gisb_arb_decode_addr(dev_id, "target abort"); 268 269 return IRQ_HANDLED; 270 } 271 272 /* 273 * Dump out gisb errors on die or panic. 274 */ 275 static int dump_gisb_error(struct notifier_block *self, unsigned long v, 276 void *p); 277 278 static struct notifier_block gisb_die_notifier = { 279 .notifier_call = dump_gisb_error, 280 }; 281 282 static struct notifier_block gisb_panic_notifier = { 283 .notifier_call = dump_gisb_error, 284 }; 285 286 static int dump_gisb_error(struct notifier_block *self, unsigned long v, 287 void *p) 288 { 289 struct brcmstb_gisb_arb_device *gdev; 290 const char *reason = "panic"; 291 292 if (self == &gisb_die_notifier) 293 reason = "die"; 294 295 /* iterate over each GISB arb registered handlers */ 296 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) 297 brcmstb_gisb_arb_decode_addr(gdev, reason); 298 299 return NOTIFY_DONE; 300 } 301 302 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO, 303 gisb_arb_get_timeout, gisb_arb_set_timeout); 304 305 static struct attribute *gisb_arb_sysfs_attrs[] = { 306 &dev_attr_gisb_arb_timeout.attr, 307 NULL, 308 }; 309 310 static struct attribute_group gisb_arb_sysfs_attr_group = { 311 .attrs = gisb_arb_sysfs_attrs, 312 }; 313 314 static const struct of_device_id brcmstb_gisb_arb_of_match[] = { 315 { .compatible = "brcm,gisb-arb", .data = gisb_offsets_bcm7445 }, 316 { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 }, 317 { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 }, 318 { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 }, 319 { .compatible = "brcm,bcm7278-gisb-arb", .data = gisb_offsets_bcm7278 }, 320 { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 }, 321 { }, 322 }; 323 324 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev) 325 { 326 struct device_node *dn = pdev->dev.of_node; 327 struct brcmstb_gisb_arb_device *gdev; 328 const struct of_device_id *of_id; 329 struct resource *r; 330 int err, timeout_irq, tea_irq; 331 unsigned int num_masters, j = 0; 332 int i, first, last; 333 334 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 335 timeout_irq = platform_get_irq(pdev, 0); 336 tea_irq = platform_get_irq(pdev, 1); 337 338 gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL); 339 if (!gdev) 340 return -ENOMEM; 341 342 mutex_init(&gdev->lock); 343 INIT_LIST_HEAD(&gdev->next); 344 345 gdev->base = devm_ioremap_resource(&pdev->dev, r); 346 if (IS_ERR(gdev->base)) 347 return PTR_ERR(gdev->base); 348 349 of_id = of_match_node(brcmstb_gisb_arb_of_match, dn); 350 if (!of_id) { 351 pr_err("failed to look up compatible string\n"); 352 return -EINVAL; 353 } 354 gdev->gisb_offsets = of_id->data; 355 gdev->big_endian = of_device_is_big_endian(dn); 356 357 err = devm_request_irq(&pdev->dev, timeout_irq, 358 brcmstb_gisb_timeout_handler, 0, pdev->name, 359 gdev); 360 if (err < 0) 361 return err; 362 363 err = devm_request_irq(&pdev->dev, tea_irq, 364 brcmstb_gisb_tea_handler, 0, pdev->name, 365 gdev); 366 if (err < 0) 367 return err; 368 369 /* If we do not have a valid mask, assume all masters are enabled */ 370 if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask", 371 &gdev->valid_mask)) 372 gdev->valid_mask = 0xffffffff; 373 374 /* Proceed with reading the litteral names if we agree on the 375 * number of masters 376 */ 377 num_masters = of_property_count_strings(dn, 378 "brcm,gisb-arb-master-names"); 379 if (hweight_long(gdev->valid_mask) == num_masters) { 380 first = ffs(gdev->valid_mask) - 1; 381 last = fls(gdev->valid_mask) - 1; 382 383 for (i = first; i < last; i++) { 384 if (!(gdev->valid_mask & BIT(i))) 385 continue; 386 387 of_property_read_string_index(dn, 388 "brcm,gisb-arb-master-names", j, 389 &gdev->master_names[i]); 390 j++; 391 } 392 } 393 394 err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group); 395 if (err) 396 return err; 397 398 platform_set_drvdata(pdev, gdev); 399 400 list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list); 401 402 #ifdef CONFIG_MIPS 403 board_be_handler = brcmstb_bus_error_handler; 404 #endif 405 406 if (list_is_singular(&brcmstb_gisb_arb_device_list)) { 407 register_die_notifier(&gisb_die_notifier); 408 atomic_notifier_chain_register(&panic_notifier_list, 409 &gisb_panic_notifier); 410 } 411 412 dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n", 413 gdev->base, timeout_irq, tea_irq); 414 415 return 0; 416 } 417 418 #ifdef CONFIG_PM_SLEEP 419 static int brcmstb_gisb_arb_suspend(struct device *dev) 420 { 421 struct platform_device *pdev = to_platform_device(dev); 422 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev); 423 424 gdev->saved_timeout = gisb_read(gdev, ARB_TIMER); 425 426 return 0; 427 } 428 429 /* Make sure we provide the same timeout value that was configured before, and 430 * do this before the GISB timeout interrupt handler has any chance to run. 431 */ 432 static int brcmstb_gisb_arb_resume_noirq(struct device *dev) 433 { 434 struct platform_device *pdev = to_platform_device(dev); 435 struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev); 436 437 gisb_write(gdev, gdev->saved_timeout, ARB_TIMER); 438 439 return 0; 440 } 441 #else 442 #define brcmstb_gisb_arb_suspend NULL 443 #define brcmstb_gisb_arb_resume_noirq NULL 444 #endif 445 446 static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = { 447 .suspend = brcmstb_gisb_arb_suspend, 448 .resume_noirq = brcmstb_gisb_arb_resume_noirq, 449 }; 450 451 static struct platform_driver brcmstb_gisb_arb_driver = { 452 .driver = { 453 .name = "brcm-gisb-arb", 454 .of_match_table = brcmstb_gisb_arb_of_match, 455 .pm = &brcmstb_gisb_arb_pm_ops, 456 }, 457 }; 458 459 static int __init brcm_gisb_driver_init(void) 460 { 461 return platform_driver_probe(&brcmstb_gisb_arb_driver, 462 brcmstb_gisb_arb_probe); 463 } 464 465 module_init(brcm_gisb_driver_init); 466