1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2014-2021 Broadcom
4 */
5
6 #include <linux/init.h>
7 #include <linux/types.h>
8 #include <linux/module.h>
9 #include <linux/panic_notifier.h>
10 #include <linux/platform_device.h>
11 #include <linux/interrupt.h>
12 #include <linux/sysfs.h>
13 #include <linux/io.h>
14 #include <linux/string.h>
15 #include <linux/device.h>
16 #include <linux/list.h>
17 #include <linux/of.h>
18 #include <linux/bitops.h>
19 #include <linux/pm.h>
20 #include <linux/kernel.h>
21 #include <linux/kdebug.h>
22 #include <linux/notifier.h>
23
24 #ifdef CONFIG_MIPS
25 #include <asm/traps.h>
26 #endif
27
28 #define ARB_ERR_CAP_CLEAR (1 << 0)
29 #define ARB_ERR_CAP_STATUS_TIMEOUT (1 << 12)
30 #define ARB_ERR_CAP_STATUS_TEA (1 << 11)
31 #define ARB_ERR_CAP_STATUS_WRITE (1 << 1)
32 #define ARB_ERR_CAP_STATUS_VALID (1 << 0)
33
34 #define ARB_BP_CAP_CLEAR (1 << 0)
35 #define ARB_BP_CAP_STATUS_PROT_SHIFT 14
36 #define ARB_BP_CAP_STATUS_TYPE (1 << 13)
37 #define ARB_BP_CAP_STATUS_RSP_SHIFT 10
38 #define ARB_BP_CAP_STATUS_MASK GENMASK(1, 0)
39 #define ARB_BP_CAP_STATUS_BS_SHIFT 2
40 #define ARB_BP_CAP_STATUS_WRITE (1 << 1)
41 #define ARB_BP_CAP_STATUS_VALID (1 << 0)
42
43 enum {
44 ARB_TIMER,
45 ARB_BP_CAP_CLR,
46 ARB_BP_CAP_HI_ADDR,
47 ARB_BP_CAP_ADDR,
48 ARB_BP_CAP_STATUS,
49 ARB_BP_CAP_MASTER,
50 ARB_ERR_CAP_CLR,
51 ARB_ERR_CAP_HI_ADDR,
52 ARB_ERR_CAP_ADDR,
53 ARB_ERR_CAP_STATUS,
54 ARB_ERR_CAP_MASTER,
55 };
56
57 static const int gisb_offsets_bcm7038[] = {
58 [ARB_TIMER] = 0x00c,
59 [ARB_BP_CAP_CLR] = 0x014,
60 [ARB_BP_CAP_HI_ADDR] = -1,
61 [ARB_BP_CAP_ADDR] = 0x0b8,
62 [ARB_BP_CAP_STATUS] = 0x0c0,
63 [ARB_BP_CAP_MASTER] = -1,
64 [ARB_ERR_CAP_CLR] = 0x0c4,
65 [ARB_ERR_CAP_HI_ADDR] = -1,
66 [ARB_ERR_CAP_ADDR] = 0x0c8,
67 [ARB_ERR_CAP_STATUS] = 0x0d0,
68 [ARB_ERR_CAP_MASTER] = -1,
69 };
70
71 static const int gisb_offsets_bcm7278[] = {
72 [ARB_TIMER] = 0x008,
73 [ARB_BP_CAP_CLR] = 0x01c,
74 [ARB_BP_CAP_HI_ADDR] = -1,
75 [ARB_BP_CAP_ADDR] = 0x220,
76 [ARB_BP_CAP_STATUS] = 0x230,
77 [ARB_BP_CAP_MASTER] = 0x234,
78 [ARB_ERR_CAP_CLR] = 0x7f8,
79 [ARB_ERR_CAP_HI_ADDR] = -1,
80 [ARB_ERR_CAP_ADDR] = 0x7e0,
81 [ARB_ERR_CAP_STATUS] = 0x7f0,
82 [ARB_ERR_CAP_MASTER] = 0x7f4,
83 };
84
85 static const int gisb_offsets_bcm7400[] = {
86 [ARB_TIMER] = 0x00c,
87 [ARB_BP_CAP_CLR] = 0x014,
88 [ARB_BP_CAP_HI_ADDR] = -1,
89 [ARB_BP_CAP_ADDR] = 0x0b8,
90 [ARB_BP_CAP_STATUS] = 0x0c0,
91 [ARB_BP_CAP_MASTER] = 0x0c4,
92 [ARB_ERR_CAP_CLR] = 0x0c8,
93 [ARB_ERR_CAP_HI_ADDR] = -1,
94 [ARB_ERR_CAP_ADDR] = 0x0cc,
95 [ARB_ERR_CAP_STATUS] = 0x0d4,
96 [ARB_ERR_CAP_MASTER] = 0x0d8,
97 };
98
99 static const int gisb_offsets_bcm74165[] = {
100 [ARB_TIMER] = 0x008,
101 [ARB_BP_CAP_CLR] = 0x044,
102 [ARB_BP_CAP_HI_ADDR] = -1,
103 [ARB_BP_CAP_ADDR] = 0x048,
104 [ARB_BP_CAP_STATUS] = 0x058,
105 [ARB_BP_CAP_MASTER] = 0x05c,
106 [ARB_ERR_CAP_CLR] = 0x038,
107 [ARB_ERR_CAP_HI_ADDR] = -1,
108 [ARB_ERR_CAP_ADDR] = 0x020,
109 [ARB_ERR_CAP_STATUS] = 0x030,
110 [ARB_ERR_CAP_MASTER] = 0x034,
111 };
112
113 static const int gisb_offsets_bcm7435[] = {
114 [ARB_TIMER] = 0x00c,
115 [ARB_BP_CAP_CLR] = 0x014,
116 [ARB_BP_CAP_HI_ADDR] = -1,
117 [ARB_BP_CAP_ADDR] = 0x158,
118 [ARB_BP_CAP_STATUS] = 0x160,
119 [ARB_BP_CAP_MASTER] = 0x164,
120 [ARB_ERR_CAP_CLR] = 0x168,
121 [ARB_ERR_CAP_HI_ADDR] = -1,
122 [ARB_ERR_CAP_ADDR] = 0x16c,
123 [ARB_ERR_CAP_STATUS] = 0x174,
124 [ARB_ERR_CAP_MASTER] = 0x178,
125 };
126
127 static const int gisb_offsets_bcm7445[] = {
128 [ARB_TIMER] = 0x008,
129 [ARB_BP_CAP_CLR] = 0x010,
130 [ARB_BP_CAP_HI_ADDR] = -1,
131 [ARB_BP_CAP_ADDR] = 0x1d8,
132 [ARB_BP_CAP_STATUS] = 0x1e0,
133 [ARB_BP_CAP_MASTER] = 0x1e4,
134 [ARB_ERR_CAP_CLR] = 0x7e4,
135 [ARB_ERR_CAP_HI_ADDR] = 0x7e8,
136 [ARB_ERR_CAP_ADDR] = 0x7ec,
137 [ARB_ERR_CAP_STATUS] = 0x7f4,
138 [ARB_ERR_CAP_MASTER] = 0x7f8,
139 };
140
141 struct brcmstb_gisb_arb_device {
142 void __iomem *base;
143 const int *gisb_offsets;
144 bool big_endian;
145 struct mutex lock;
146 struct list_head next;
147 u32 valid_mask;
148 const char *master_names[sizeof(u32) * BITS_PER_BYTE];
149 u32 saved_timeout;
150 };
151
152 static LIST_HEAD(brcmstb_gisb_arb_device_list);
153
gisb_read(struct brcmstb_gisb_arb_device * gdev,int reg)154 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
155 {
156 int offset = gdev->gisb_offsets[reg];
157
158 if (offset < 0) {
159 /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
160 if (reg == ARB_ERR_CAP_MASTER)
161 return 1;
162 else
163 return 0;
164 }
165
166 if (gdev->big_endian)
167 return ioread32be(gdev->base + offset);
168 else
169 return ioread32(gdev->base + offset);
170 }
171
gisb_read_address(struct brcmstb_gisb_arb_device * gdev)172 static u64 gisb_read_address(struct brcmstb_gisb_arb_device *gdev)
173 {
174 u64 value;
175
176 value = gisb_read(gdev, ARB_ERR_CAP_ADDR);
177 value |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
178
179 return value;
180 }
181
gisb_read_bp_address(struct brcmstb_gisb_arb_device * gdev)182 static u64 gisb_read_bp_address(struct brcmstb_gisb_arb_device *gdev)
183 {
184 u64 value;
185
186 value = gisb_read(gdev, ARB_BP_CAP_ADDR);
187 value |= (u64)gisb_read(gdev, ARB_BP_CAP_HI_ADDR) << 32;
188
189 return value;
190 }
191
gisb_write(struct brcmstb_gisb_arb_device * gdev,u32 val,int reg)192 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
193 {
194 int offset = gdev->gisb_offsets[reg];
195
196 if (offset == -1)
197 return;
198
199 if (gdev->big_endian)
200 iowrite32be(val, gdev->base + offset);
201 else
202 iowrite32(val, gdev->base + offset);
203 }
204
gisb_arb_get_timeout(struct device * dev,struct device_attribute * attr,char * buf)205 static ssize_t gisb_arb_get_timeout(struct device *dev,
206 struct device_attribute *attr,
207 char *buf)
208 {
209 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
210 u32 timeout;
211
212 mutex_lock(&gdev->lock);
213 timeout = gisb_read(gdev, ARB_TIMER);
214 mutex_unlock(&gdev->lock);
215
216 return sprintf(buf, "%d", timeout);
217 }
218
gisb_arb_set_timeout(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)219 static ssize_t gisb_arb_set_timeout(struct device *dev,
220 struct device_attribute *attr,
221 const char *buf, size_t count)
222 {
223 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
224 int val, ret;
225
226 ret = kstrtoint(buf, 10, &val);
227 if (ret < 0)
228 return ret;
229
230 if (val == 0 || val >= 0xffffffff)
231 return -EINVAL;
232
233 mutex_lock(&gdev->lock);
234 gisb_write(gdev, val, ARB_TIMER);
235 mutex_unlock(&gdev->lock);
236
237 return count;
238 }
239
240 static const char *
brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device * gdev,u32 masters)241 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
242 u32 masters)
243 {
244 u32 mask = gdev->valid_mask & masters;
245
246 if (hweight_long(mask) != 1)
247 return NULL;
248
249 return gdev->master_names[ffs(mask) - 1];
250 }
251
brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device * gdev,const char * reason)252 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
253 const char *reason)
254 {
255 u32 cap_status;
256 u64 arb_addr;
257 u32 master;
258 const char *m_name;
259 char m_fmt[11];
260
261 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
262
263 /* Invalid captured address, bail out */
264 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
265 return 1;
266
267 /* Read the address and master */
268 arb_addr = gisb_read_address(gdev);
269 master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
270
271 m_name = brcmstb_gisb_master_to_str(gdev, master);
272 if (!m_name) {
273 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
274 m_name = m_fmt;
275 }
276
277 pr_crit("GISB: %s at 0x%llx [%c %s], core: %s\n",
278 reason, arb_addr,
279 cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
280 cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
281 m_name);
282
283 /* clear the GISB error */
284 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
285
286 return 0;
287 }
288
289 #ifdef CONFIG_MIPS
brcmstb_bus_error_handler(struct pt_regs * regs,int is_fixup)290 static int brcmstb_bus_error_handler(struct pt_regs *regs, int is_fixup)
291 {
292 int ret = 0;
293 struct brcmstb_gisb_arb_device *gdev;
294 u32 cap_status;
295
296 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) {
297 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
298
299 /* Invalid captured address, bail out */
300 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) {
301 is_fixup = 1;
302 goto out;
303 }
304
305 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
306 }
307 out:
308 return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
309 }
310 #endif
311
brcmstb_gisb_timeout_handler(int irq,void * dev_id)312 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
313 {
314 brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
315
316 return IRQ_HANDLED;
317 }
318
brcmstb_gisb_tea_handler(int irq,void * dev_id)319 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
320 {
321 brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
322
323 return IRQ_HANDLED;
324 }
325
brcmstb_gisb_bp_handler(int irq,void * dev_id)326 static irqreturn_t brcmstb_gisb_bp_handler(int irq, void *dev_id)
327 {
328 struct brcmstb_gisb_arb_device *gdev = dev_id;
329 const char *m_name;
330 u32 bp_status;
331 u64 arb_addr;
332 u32 master;
333 char m_fmt[11];
334
335 bp_status = gisb_read(gdev, ARB_BP_CAP_STATUS);
336
337 /* Invalid captured address, bail out */
338 if (!(bp_status & ARB_BP_CAP_STATUS_VALID))
339 return IRQ_HANDLED;
340
341 /* Read the address and master */
342 arb_addr = gisb_read_bp_address(gdev);
343 master = gisb_read(gdev, ARB_BP_CAP_MASTER);
344
345 m_name = brcmstb_gisb_master_to_str(gdev, master);
346 if (!m_name) {
347 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
348 m_name = m_fmt;
349 }
350
351 pr_crit("GISB: breakpoint at 0x%llx [%c], core: %s\n",
352 arb_addr, bp_status & ARB_BP_CAP_STATUS_WRITE ? 'W' : 'R',
353 m_name);
354
355 /* clear the GISB error */
356 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
357
358 return IRQ_HANDLED;
359 }
360
361 /*
362 * Dump out gisb errors on die or panic.
363 */
364 static int dump_gisb_error(struct notifier_block *self, unsigned long v,
365 void *p);
366
367 static struct notifier_block gisb_die_notifier = {
368 .notifier_call = dump_gisb_error,
369 };
370
371 static struct notifier_block gisb_panic_notifier = {
372 .notifier_call = dump_gisb_error,
373 };
374
dump_gisb_error(struct notifier_block * self,unsigned long v,void * p)375 static int dump_gisb_error(struct notifier_block *self, unsigned long v,
376 void *p)
377 {
378 struct brcmstb_gisb_arb_device *gdev;
379 const char *reason = "panic";
380
381 if (self == &gisb_die_notifier)
382 reason = "die";
383
384 /* iterate over each GISB arb registered handlers */
385 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
386 brcmstb_gisb_arb_decode_addr(gdev, reason);
387
388 return NOTIFY_DONE;
389 }
390
391 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
392 gisb_arb_get_timeout, gisb_arb_set_timeout);
393
394 static struct attribute *gisb_arb_sysfs_attrs[] = {
395 &dev_attr_gisb_arb_timeout.attr,
396 NULL,
397 };
398
399 static struct attribute_group gisb_arb_sysfs_attr_group = {
400 .attrs = gisb_arb_sysfs_attrs,
401 };
402
403 static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
404 { .compatible = "brcm,gisb-arb", .data = gisb_offsets_bcm7445 },
405 { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
406 { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
407 { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
408 { .compatible = "brcm,bcm7278-gisb-arb", .data = gisb_offsets_bcm7278 },
409 { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
410 { .compatible = "brcm,bcm74165-gisb-arb", .data = gisb_offsets_bcm74165 },
411 { },
412 };
413 MODULE_DEVICE_TABLE(of, brcmstb_gisb_arb_of_match);
414
brcmstb_gisb_arb_probe(struct platform_device * pdev)415 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
416 {
417 struct device_node *dn = pdev->dev.of_node;
418 struct brcmstb_gisb_arb_device *gdev;
419 const struct of_device_id *of_id;
420 int err, timeout_irq, tea_irq, bp_irq;
421 unsigned int num_masters, j = 0;
422 int i, first, last;
423
424 timeout_irq = platform_get_irq(pdev, 0);
425 tea_irq = platform_get_irq(pdev, 1);
426 bp_irq = platform_get_irq(pdev, 2);
427
428 gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
429 if (!gdev)
430 return -ENOMEM;
431
432 mutex_init(&gdev->lock);
433 INIT_LIST_HEAD(&gdev->next);
434
435 gdev->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
436 if (IS_ERR(gdev->base))
437 return PTR_ERR(gdev->base);
438
439 of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
440 if (!of_id) {
441 pr_err("failed to look up compatible string\n");
442 return -EINVAL;
443 }
444 gdev->gisb_offsets = of_id->data;
445 gdev->big_endian = of_device_is_big_endian(dn);
446
447 err = devm_request_irq(&pdev->dev, timeout_irq,
448 brcmstb_gisb_timeout_handler, 0, pdev->name,
449 gdev);
450 if (err < 0)
451 return err;
452
453 err = devm_request_irq(&pdev->dev, tea_irq,
454 brcmstb_gisb_tea_handler, 0, pdev->name,
455 gdev);
456 if (err < 0)
457 return err;
458
459 /* Interrupt is optional */
460 if (bp_irq > 0) {
461 err = devm_request_irq(&pdev->dev, bp_irq,
462 brcmstb_gisb_bp_handler, 0, pdev->name,
463 gdev);
464 if (err < 0)
465 return err;
466 }
467
468 /* If we do not have a valid mask, assume all masters are enabled */
469 if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
470 &gdev->valid_mask))
471 gdev->valid_mask = 0xffffffff;
472
473 /* Proceed with reading the litteral names if we agree on the
474 * number of masters
475 */
476 num_masters = of_property_count_strings(dn,
477 "brcm,gisb-arb-master-names");
478 if (hweight_long(gdev->valid_mask) == num_masters) {
479 first = ffs(gdev->valid_mask) - 1;
480 last = fls(gdev->valid_mask) - 1;
481
482 for (i = first; i < last; i++) {
483 if (!(gdev->valid_mask & BIT(i)))
484 continue;
485
486 of_property_read_string_index(dn,
487 "brcm,gisb-arb-master-names", j,
488 &gdev->master_names[i]);
489 j++;
490 }
491 }
492
493 err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
494 if (err)
495 return err;
496
497 platform_set_drvdata(pdev, gdev);
498
499 list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
500
501 #ifdef CONFIG_MIPS
502 mips_set_be_handler(brcmstb_bus_error_handler);
503 #endif
504
505 if (list_is_singular(&brcmstb_gisb_arb_device_list)) {
506 register_die_notifier(&gisb_die_notifier);
507 atomic_notifier_chain_register(&panic_notifier_list,
508 &gisb_panic_notifier);
509 }
510
511 dev_info(&pdev->dev, "registered irqs: %d, %d\n",
512 timeout_irq, tea_irq);
513
514 return 0;
515 }
516
517 #ifdef CONFIG_PM_SLEEP
brcmstb_gisb_arb_suspend(struct device * dev)518 static int brcmstb_gisb_arb_suspend(struct device *dev)
519 {
520 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
521
522 gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
523
524 return 0;
525 }
526
527 /* Make sure we provide the same timeout value that was configured before, and
528 * do this before the GISB timeout interrupt handler has any chance to run.
529 */
brcmstb_gisb_arb_resume_noirq(struct device * dev)530 static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
531 {
532 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
533
534 gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
535
536 return 0;
537 }
538 #else
539 #define brcmstb_gisb_arb_suspend NULL
540 #define brcmstb_gisb_arb_resume_noirq NULL
541 #endif
542
543 static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
544 .suspend = brcmstb_gisb_arb_suspend,
545 .resume_noirq = brcmstb_gisb_arb_resume_noirq,
546 };
547
548 static struct platform_driver brcmstb_gisb_arb_driver = {
549 .driver = {
550 .name = "brcm-gisb-arb",
551 .of_match_table = brcmstb_gisb_arb_of_match,
552 .pm = &brcmstb_gisb_arb_pm_ops,
553 },
554 };
555
brcm_gisb_driver_init(void)556 static int __init brcm_gisb_driver_init(void)
557 {
558 return platform_driver_probe(&brcmstb_gisb_arb_driver,
559 brcmstb_gisb_arb_probe);
560 }
561
562 module_init(brcm_gisb_driver_init);
563
564 MODULE_AUTHOR("Broadcom");
565 MODULE_DESCRIPTION("Broadcom STB GISB arbiter driver");
566 MODULE_LICENSE("GPL v2");
567