1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2014-2017 Broadcom
4 */
5
6 #include <linux/init.h>
7 #include <linux/types.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/interrupt.h>
11 #include <linux/sysfs.h>
12 #include <linux/io.h>
13 #include <linux/string.h>
14 #include <linux/device.h>
15 #include <linux/list.h>
16 #include <linux/of.h>
17 #include <linux/bitops.h>
18 #include <linux/pm.h>
19 #include <linux/kernel.h>
20 #include <linux/kdebug.h>
21 #include <linux/notifier.h>
22
23 #ifdef CONFIG_MIPS
24 #include <asm/traps.h>
25 #endif
26
27 #define ARB_ERR_CAP_CLEAR (1 << 0)
28 #define ARB_ERR_CAP_STATUS_TIMEOUT (1 << 12)
29 #define ARB_ERR_CAP_STATUS_TEA (1 << 11)
30 #define ARB_ERR_CAP_STATUS_WRITE (1 << 1)
31 #define ARB_ERR_CAP_STATUS_VALID (1 << 0)
32
33 enum {
34 ARB_TIMER,
35 ARB_ERR_CAP_CLR,
36 ARB_ERR_CAP_HI_ADDR,
37 ARB_ERR_CAP_ADDR,
38 ARB_ERR_CAP_STATUS,
39 ARB_ERR_CAP_MASTER,
40 };
41
42 static const int gisb_offsets_bcm7038[] = {
43 [ARB_TIMER] = 0x00c,
44 [ARB_ERR_CAP_CLR] = 0x0c4,
45 [ARB_ERR_CAP_HI_ADDR] = -1,
46 [ARB_ERR_CAP_ADDR] = 0x0c8,
47 [ARB_ERR_CAP_STATUS] = 0x0d0,
48 [ARB_ERR_CAP_MASTER] = -1,
49 };
50
51 static const int gisb_offsets_bcm7278[] = {
52 [ARB_TIMER] = 0x008,
53 [ARB_ERR_CAP_CLR] = 0x7f8,
54 [ARB_ERR_CAP_HI_ADDR] = -1,
55 [ARB_ERR_CAP_ADDR] = 0x7e0,
56 [ARB_ERR_CAP_STATUS] = 0x7f0,
57 [ARB_ERR_CAP_MASTER] = 0x7f4,
58 };
59
60 static const int gisb_offsets_bcm7400[] = {
61 [ARB_TIMER] = 0x00c,
62 [ARB_ERR_CAP_CLR] = 0x0c8,
63 [ARB_ERR_CAP_HI_ADDR] = -1,
64 [ARB_ERR_CAP_ADDR] = 0x0cc,
65 [ARB_ERR_CAP_STATUS] = 0x0d4,
66 [ARB_ERR_CAP_MASTER] = 0x0d8,
67 };
68
69 static const int gisb_offsets_bcm7435[] = {
70 [ARB_TIMER] = 0x00c,
71 [ARB_ERR_CAP_CLR] = 0x168,
72 [ARB_ERR_CAP_HI_ADDR] = -1,
73 [ARB_ERR_CAP_ADDR] = 0x16c,
74 [ARB_ERR_CAP_STATUS] = 0x174,
75 [ARB_ERR_CAP_MASTER] = 0x178,
76 };
77
78 static const int gisb_offsets_bcm7445[] = {
79 [ARB_TIMER] = 0x008,
80 [ARB_ERR_CAP_CLR] = 0x7e4,
81 [ARB_ERR_CAP_HI_ADDR] = 0x7e8,
82 [ARB_ERR_CAP_ADDR] = 0x7ec,
83 [ARB_ERR_CAP_STATUS] = 0x7f4,
84 [ARB_ERR_CAP_MASTER] = 0x7f8,
85 };
86
87 struct brcmstb_gisb_arb_device {
88 void __iomem *base;
89 const int *gisb_offsets;
90 bool big_endian;
91 struct mutex lock;
92 struct list_head next;
93 u32 valid_mask;
94 const char *master_names[sizeof(u32) * BITS_PER_BYTE];
95 u32 saved_timeout;
96 };
97
98 static LIST_HEAD(brcmstb_gisb_arb_device_list);
99
gisb_read(struct brcmstb_gisb_arb_device * gdev,int reg)100 static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
101 {
102 int offset = gdev->gisb_offsets[reg];
103
104 if (offset < 0) {
105 /* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
106 if (reg == ARB_ERR_CAP_MASTER)
107 return 1;
108 else
109 return 0;
110 }
111
112 if (gdev->big_endian)
113 return ioread32be(gdev->base + offset);
114 else
115 return ioread32(gdev->base + offset);
116 }
117
gisb_read_address(struct brcmstb_gisb_arb_device * gdev)118 static u64 gisb_read_address(struct brcmstb_gisb_arb_device *gdev)
119 {
120 u64 value;
121
122 value = gisb_read(gdev, ARB_ERR_CAP_ADDR);
123 value |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
124
125 return value;
126 }
127
gisb_write(struct brcmstb_gisb_arb_device * gdev,u32 val,int reg)128 static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
129 {
130 int offset = gdev->gisb_offsets[reg];
131
132 if (offset == -1)
133 return;
134
135 if (gdev->big_endian)
136 iowrite32be(val, gdev->base + offset);
137 else
138 iowrite32(val, gdev->base + offset);
139 }
140
gisb_arb_get_timeout(struct device * dev,struct device_attribute * attr,char * buf)141 static ssize_t gisb_arb_get_timeout(struct device *dev,
142 struct device_attribute *attr,
143 char *buf)
144 {
145 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
146 u32 timeout;
147
148 mutex_lock(&gdev->lock);
149 timeout = gisb_read(gdev, ARB_TIMER);
150 mutex_unlock(&gdev->lock);
151
152 return sprintf(buf, "%d", timeout);
153 }
154
gisb_arb_set_timeout(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)155 static ssize_t gisb_arb_set_timeout(struct device *dev,
156 struct device_attribute *attr,
157 const char *buf, size_t count)
158 {
159 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
160 int val, ret;
161
162 ret = kstrtoint(buf, 10, &val);
163 if (ret < 0)
164 return ret;
165
166 if (val == 0 || val >= 0xffffffff)
167 return -EINVAL;
168
169 mutex_lock(&gdev->lock);
170 gisb_write(gdev, val, ARB_TIMER);
171 mutex_unlock(&gdev->lock);
172
173 return count;
174 }
175
176 static const char *
brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device * gdev,u32 masters)177 brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
178 u32 masters)
179 {
180 u32 mask = gdev->valid_mask & masters;
181
182 if (hweight_long(mask) != 1)
183 return NULL;
184
185 return gdev->master_names[ffs(mask) - 1];
186 }
187
brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device * gdev,const char * reason)188 static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
189 const char *reason)
190 {
191 u32 cap_status;
192 u64 arb_addr;
193 u32 master;
194 const char *m_name;
195 char m_fmt[11];
196
197 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
198
199 /* Invalid captured address, bail out */
200 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
201 return 1;
202
203 /* Read the address and master */
204 arb_addr = gisb_read_address(gdev);
205 master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
206
207 m_name = brcmstb_gisb_master_to_str(gdev, master);
208 if (!m_name) {
209 snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
210 m_name = m_fmt;
211 }
212
213 pr_crit("%s: %s at 0x%llx [%c %s], core: %s\n",
214 __func__, reason, arb_addr,
215 cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
216 cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
217 m_name);
218
219 /* clear the GISB error */
220 gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
221
222 return 0;
223 }
224
225 #ifdef CONFIG_MIPS
brcmstb_bus_error_handler(struct pt_regs * regs,int is_fixup)226 static int brcmstb_bus_error_handler(struct pt_regs *regs, int is_fixup)
227 {
228 int ret = 0;
229 struct brcmstb_gisb_arb_device *gdev;
230 u32 cap_status;
231
232 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) {
233 cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
234
235 /* Invalid captured address, bail out */
236 if (!(cap_status & ARB_ERR_CAP_STATUS_VALID)) {
237 is_fixup = 1;
238 goto out;
239 }
240
241 ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
242 }
243 out:
244 return is_fixup ? MIPS_BE_FIXUP : MIPS_BE_FATAL;
245 }
246 #endif
247
brcmstb_gisb_timeout_handler(int irq,void * dev_id)248 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
249 {
250 brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
251
252 return IRQ_HANDLED;
253 }
254
brcmstb_gisb_tea_handler(int irq,void * dev_id)255 static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
256 {
257 brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
258
259 return IRQ_HANDLED;
260 }
261
262 /*
263 * Dump out gisb errors on die or panic.
264 */
265 static int dump_gisb_error(struct notifier_block *self, unsigned long v,
266 void *p);
267
268 static struct notifier_block gisb_die_notifier = {
269 .notifier_call = dump_gisb_error,
270 };
271
272 static struct notifier_block gisb_panic_notifier = {
273 .notifier_call = dump_gisb_error,
274 };
275
dump_gisb_error(struct notifier_block * self,unsigned long v,void * p)276 static int dump_gisb_error(struct notifier_block *self, unsigned long v,
277 void *p)
278 {
279 struct brcmstb_gisb_arb_device *gdev;
280 const char *reason = "panic";
281
282 if (self == &gisb_die_notifier)
283 reason = "die";
284
285 /* iterate over each GISB arb registered handlers */
286 list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
287 brcmstb_gisb_arb_decode_addr(gdev, reason);
288
289 return NOTIFY_DONE;
290 }
291
292 static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
293 gisb_arb_get_timeout, gisb_arb_set_timeout);
294
295 static struct attribute *gisb_arb_sysfs_attrs[] = {
296 &dev_attr_gisb_arb_timeout.attr,
297 NULL,
298 };
299
300 static struct attribute_group gisb_arb_sysfs_attr_group = {
301 .attrs = gisb_arb_sysfs_attrs,
302 };
303
304 static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
305 { .compatible = "brcm,gisb-arb", .data = gisb_offsets_bcm7445 },
306 { .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
307 { .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
308 { .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
309 { .compatible = "brcm,bcm7278-gisb-arb", .data = gisb_offsets_bcm7278 },
310 { .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
311 { },
312 };
313
brcmstb_gisb_arb_probe(struct platform_device * pdev)314 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
315 {
316 struct device_node *dn = pdev->dev.of_node;
317 struct brcmstb_gisb_arb_device *gdev;
318 const struct of_device_id *of_id;
319 struct resource *r;
320 int err, timeout_irq, tea_irq;
321 unsigned int num_masters, j = 0;
322 int i, first, last;
323
324 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
325 timeout_irq = platform_get_irq(pdev, 0);
326 tea_irq = platform_get_irq(pdev, 1);
327
328 gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
329 if (!gdev)
330 return -ENOMEM;
331
332 mutex_init(&gdev->lock);
333 INIT_LIST_HEAD(&gdev->next);
334
335 gdev->base = devm_ioremap_resource(&pdev->dev, r);
336 if (IS_ERR(gdev->base))
337 return PTR_ERR(gdev->base);
338
339 of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
340 if (!of_id) {
341 pr_err("failed to look up compatible string\n");
342 return -EINVAL;
343 }
344 gdev->gisb_offsets = of_id->data;
345 gdev->big_endian = of_device_is_big_endian(dn);
346
347 err = devm_request_irq(&pdev->dev, timeout_irq,
348 brcmstb_gisb_timeout_handler, 0, pdev->name,
349 gdev);
350 if (err < 0)
351 return err;
352
353 err = devm_request_irq(&pdev->dev, tea_irq,
354 brcmstb_gisb_tea_handler, 0, pdev->name,
355 gdev);
356 if (err < 0)
357 return err;
358
359 /* If we do not have a valid mask, assume all masters are enabled */
360 if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
361 &gdev->valid_mask))
362 gdev->valid_mask = 0xffffffff;
363
364 /* Proceed with reading the litteral names if we agree on the
365 * number of masters
366 */
367 num_masters = of_property_count_strings(dn,
368 "brcm,gisb-arb-master-names");
369 if (hweight_long(gdev->valid_mask) == num_masters) {
370 first = ffs(gdev->valid_mask) - 1;
371 last = fls(gdev->valid_mask) - 1;
372
373 for (i = first; i < last; i++) {
374 if (!(gdev->valid_mask & BIT(i)))
375 continue;
376
377 of_property_read_string_index(dn,
378 "brcm,gisb-arb-master-names", j,
379 &gdev->master_names[i]);
380 j++;
381 }
382 }
383
384 err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
385 if (err)
386 return err;
387
388 platform_set_drvdata(pdev, gdev);
389
390 list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
391
392 #ifdef CONFIG_MIPS
393 board_be_handler = brcmstb_bus_error_handler;
394 #endif
395
396 if (list_is_singular(&brcmstb_gisb_arb_device_list)) {
397 register_die_notifier(&gisb_die_notifier);
398 atomic_notifier_chain_register(&panic_notifier_list,
399 &gisb_panic_notifier);
400 }
401
402 dev_info(&pdev->dev, "registered irqs: %d, %d\n",
403 timeout_irq, tea_irq);
404
405 return 0;
406 }
407
408 #ifdef CONFIG_PM_SLEEP
brcmstb_gisb_arb_suspend(struct device * dev)409 static int brcmstb_gisb_arb_suspend(struct device *dev)
410 {
411 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
412
413 gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
414
415 return 0;
416 }
417
418 /* Make sure we provide the same timeout value that was configured before, and
419 * do this before the GISB timeout interrupt handler has any chance to run.
420 */
brcmstb_gisb_arb_resume_noirq(struct device * dev)421 static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
422 {
423 struct brcmstb_gisb_arb_device *gdev = dev_get_drvdata(dev);
424
425 gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
426
427 return 0;
428 }
429 #else
430 #define brcmstb_gisb_arb_suspend NULL
431 #define brcmstb_gisb_arb_resume_noirq NULL
432 #endif
433
434 static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
435 .suspend = brcmstb_gisb_arb_suspend,
436 .resume_noirq = brcmstb_gisb_arb_resume_noirq,
437 };
438
439 static struct platform_driver brcmstb_gisb_arb_driver = {
440 .driver = {
441 .name = "brcm-gisb-arb",
442 .of_match_table = brcmstb_gisb_arb_of_match,
443 .pm = &brcmstb_gisb_arb_pm_ops,
444 },
445 };
446
brcm_gisb_driver_init(void)447 static int __init brcm_gisb_driver_init(void)
448 {
449 return platform_driver_probe(&brcmstb_gisb_arb_driver,
450 brcmstb_gisb_arb_probe);
451 }
452
453 module_init(brcm_gisb_driver_init);
454