drivers/bus/brcmstb_gisb.c

   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 brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
 154         u32 timeout;
 155
 156         mutex_lock(&gdev->lock);
 157         timeout = gisb_read(gdev, ARB_TIMER);
 158         mutex_unlock(&gdev->lock);
 159
 160         return sprintf(buf, "%d", timeout);
 161 }
 162
 163 static ssize_t gisb_arb_set_timeout(struct device *dev,
 164                                     struct device_attribute *attr,
 165                                     const char *buf, size_t count)
 166 {
 167         struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
 168         int val, ret;
 169
 170         ret = kstrtoint(buf, 10, &val);
 171         if (ret < 0)
 172                 return ret;
 173
 174         if (val == 0 || val >= 0xffffffff)
 175                 return -EINVAL;
 176
 177         mutex_lock(&gdev->lock);
 178         gisb_write(gdev, val, ARB_TIMER);
 179         mutex_unlock(&gdev->lock);
 180
 181         return count;
 182 }
 183
 184 static const char *
 185 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
 186                                                 u32 masters)
 187 {
 188         u32 mask = gdev->valid_mask & masters;
 189
 190         if (hweight_long(mask) != 1)
 191                 return NULL;
 192
 193         return gdev->master_names[ffs(mask) - 1];
 194 }
 195
 196 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
 197                                         const char *reason)
 198 {
 199         u32 cap_status;
 200         u64 arb_addr;
 201         u32 master;
 202         const char *m_name;
 203         char m_fmt[11];
 204
 205         cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
 206
 207         /* Invalid captured address, bail out */
 208         if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
 209                 return 1;
 210
 211         /* Read the address and master */
 212         arb_addr = gisb_read_address(gdev);
 213         master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
 214
 215         m_name = brcmstb_gisb_master_to_str(gdev, master);
 216         if (!m_name) {
 217                 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
 218                 m_name = m_fmt;
 219         }
 220
 221         pr_crit("%s: %s at 0x%llx [%c %s], core: %s\n",
 222                 __func__, reason, arb_addr,
 223                 cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
 224                 cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
 225                 m_name);
 226
 227         /* clear the GISB error */
 228         gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
 229
 230         return 0;
 231 }
 232
 233 #ifdef CONFIG_MIPS
 234 static int brcmstb_bus_error_handler(struct pt_regs *regs, int is_fixup)
 235 {
 236         int ret = 0;
 237         struct brcmstb_gisb_arb_device *gdev;
 238         u32 cap_status;
 239
 240         list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) {
 241                 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
 242
 243                 /* Invalid captured address, bail out */
 244                 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) {
 245                         is_fixup = 1;
 246                         goto out;
 247                 }
 248
 249                 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
 250         }
 251 out:
 252         return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
 253 }
 254 #endif
 255
 256 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
 257 {
 258         brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
 259
 260         return IRQ_HANDLED;
 261 }
 262
 263 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
 264 {
 265         brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
 266
 267         return IRQ_HANDLED;
 268 }
 269
 270 /*
 271  * Dump out gisb errors on die or panic.
 272  */
 273 static int dump_gisb_error(struct notifier_block *self, unsigned long v,
 274                            void *p);
 275
 276 static struct notifier_block gisb_die_notifier = {
 277         .notifier_call = dump_gisb_error,
 278 };
 279
 280 static struct notifier_block gisb_panic_notifier = {
 281         .notifier_call = dump_gisb_error,
 282 };
 283
 284 static int dump_gisb_error(struct notifier_block *self, unsigned long v,
 285                            void *p)
 286 {
 287         struct brcmstb_gisb_arb_device *gdev;
 288         const char *reason = "panic";
 289
 290         if (self == &gisb_die_notifier)
 291                 reason = "die";
 292
 293         /* iterate over each GISB arb registered handlers */
 294         list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
 295                 brcmstb_gisb_arb_decode_addr(gdev, reason);
 296
 297         return NOTIFY_DONE;
 298 }
 299
 300 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
 301                 gisb_arb_get_timeout, gisb_arb_set_timeout);
 302
 303 static struct attribute *gisb_arb_sysfs_attrs[] = {
 304         &dev_attr_gisb_arb_timeout.attr,
 305         NULL,
 306 };
 307
 308 static struct attribute_group gisb_arb_sysfs_attr_group = {
 309         .attrs = gisb_arb_sysfs_attrs,
 310 };
 311
 312 static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
 313         { .compatible = "brcm,gisb-arb",         .data = gisb_offsets_bcm7445 },
 314         { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
 315         { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
 316         { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
 317         { .compatible = "brcm,bcm7278-gisb-arb", .data = gisb_offsets_bcm7278 },
 318         { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
 319         { },
 320 };
 321
 322 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
 323 {
 324         struct device_node *dn = pdev->dev.of_node;
 325         struct brcmstb_gisb_arb_device *gdev;
 326         const struct of_device_id *of_id;
 327         struct resource *r;
 328         int err, timeout_irq, tea_irq;
 329         unsigned int num_masters, j = 0;
 330         int i, first, last;
 331
 332         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 333         timeout_irq = platform_get_irq(pdev, 0);
 334         tea_irq = platform_get_irq(pdev, 1);
 335
 336         gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
 337         if (!gdev)
 338                 return -ENOMEM;
 339
 340         mutex_init(&gdev->lock);
 341         INIT_LIST_HEAD(&gdev->next);
 342
 343         gdev->base = devm_ioremap_resource(&pdev->dev, r);
 344         if (IS_ERR(gdev->base))
 345                 return PTR_ERR(gdev->base);
 346
 347         of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
 348         if (!of_id) {
 349                 pr_err("failed to look up compatible string\n");
 350                 return -EINVAL;
 351         }
 352         gdev->gisb_offsets = of_id->data;
 353         gdev->big_endian = of_device_is_big_endian(dn);
 354
 355         err = devm_request_irq(&pdev->dev, timeout_irq,
 356                                 brcmstb_gisb_timeout_handler, 0, pdev->name,
 357                                 gdev);
 358         if (err < 0)
 359                 return err;
 360
 361         err = devm_request_irq(&pdev->dev, tea_irq,
 362                                 brcmstb_gisb_tea_handler, 0, pdev->name,
 363                                 gdev);
 364         if (err < 0)
 365                 return err;
 366
 367         /* If we do not have a valid mask, assume all masters are enabled */
 368         if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
 369                                 &gdev->valid_mask))
 370                 gdev->valid_mask = 0xffffffff;
 371
 372         /* Proceed with reading the litteral names if we agree on the
 373          * number of masters
 374          */
 375         num_masters = of_property_count_strings(dn,
 376                         "brcm,gisb-arb-master-names");
 377         if (hweight_long(gdev->valid_mask) == num_masters) {
 378                 first = ffs(gdev->valid_mask) - 1;
 379                 last = fls(gdev->valid_mask) - 1;
 380
 381                 for (i = first; i < last; i++) {
 382                         if (!(gdev->valid_mask & BIT(i)))
 383                                 continue;
 384
 385                         of_property_read_string_index(dn,
 386                                         "brcm,gisb-arb-master-names", j,
 387                                         &gdev->master_names[i]);
 388                         j++;
 389                 }
 390         }
 391
 392         err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
 393         if (err)
 394                 return err;
 395
 396         platform_set_drvdata(pdev, gdev);
 397
 398         list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
 399
 400 #ifdef CONFIG_MIPS
 401         board_be_handler = brcmstb_bus_error_handler;
 402 #endif
 403
 404         if (list_is_singular(&brcmstb_gisb_arb_device_list)) {
 405                 register_die_notifier(&gisb_die_notifier);
 406                 atomic_notifier_chain_register(&panic_notifier_list,
 407                                                &gisb_panic_notifier);
 408         }
 409
 410         dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
 411                         gdev->base, timeout_irq, tea_irq);
 412
 413         return 0;
 414 }
 415
 416 #ifdef CONFIG_PM_SLEEP
 417 static int brcmstb_gisb_arb_suspend(struct device *dev)
 418 {
 419         struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
 420
 421         gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
 422
 423         return 0;
 424 }
 425
 426 /* Make sure we provide the same timeout value that was configured before, and
 427  * do this before the GISB timeout interrupt handler has any chance to run.
 428  */
 429 static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
 430 {
 431         struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
 432
 433         gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
 434
 435         return 0;
 436 }
 437 #else
 438 #define brcmstb_gisb_arb_suspend       NULL
 439 #define brcmstb_gisb_arb_resume_noirq  NULL
 440 #endif
 441
 442 static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
 443         .suspend        = brcmstb_gisb_arb_suspend,
 444         .resume_noirq   = brcmstb_gisb_arb_resume_noirq,
 445 };
 446
 447 static struct platform_driver brcmstb_gisb_arb_driver = {
 448         .driver = {
 449                 .name   = "brcm-gisb-arb",
 450                 .of_match_table = brcmstb_gisb_arb_of_match,
 451                 .pm     = &brcmstb_gisb_arb_pm_ops,
 452         },
 453 };
 454
 455 static int __init brcm_gisb_driver_init(void)
 456 {
 457         return platform_driver_probe(&brcmstb_gisb_arb_driver,
 458                                      brcmstb_gisb_arb_probe);
 459 }
 460
 461 module_init(brcm_gisb_driver_init);