RISC-V: Fix a race condition during kernel stack overflow
[platform/kernel/linux-starfive.git] / arch / mips / kernel / mips-cm.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2013 Imagination Technologies
4  * Author: Paul Burton <paul.burton@mips.com>
5  */
6
7 #include <linux/errno.h>
8 #include <linux/percpu.h>
9 #include <linux/spinlock.h>
10
11 #include <asm/mips-cps.h>
12 #include <asm/mipsregs.h>
13
14 void __iomem *mips_gcr_base;
15 void __iomem *mips_cm_l2sync_base;
16 int mips_cm_is64;
17
18 static char *cm2_tr[8] = {
19         "mem",  "gcr",  "gic",  "mmio",
20         "0x04", "cpc", "0x06", "0x07"
21 };
22
23 /* CM3 Tag ECC transaction type */
24 static char *cm3_tr[16] = {
25         [0x0] = "ReqNoData",
26         [0x1] = "0x1",
27         [0x2] = "ReqWData",
28         [0x3] = "0x3",
29         [0x4] = "IReqNoResp",
30         [0x5] = "IReqWResp",
31         [0x6] = "IReqNoRespDat",
32         [0x7] = "IReqWRespDat",
33         [0x8] = "RespNoData",
34         [0x9] = "RespDataFol",
35         [0xa] = "RespWData",
36         [0xb] = "RespDataOnly",
37         [0xc] = "IRespNoData",
38         [0xd] = "IRespDataFol",
39         [0xe] = "IRespWData",
40         [0xf] = "IRespDataOnly"
41 };
42
43 static char *cm2_cmd[32] = {
44         [0x00] = "0x00",
45         [0x01] = "Legacy Write",
46         [0x02] = "Legacy Read",
47         [0x03] = "0x03",
48         [0x04] = "0x04",
49         [0x05] = "0x05",
50         [0x06] = "0x06",
51         [0x07] = "0x07",
52         [0x08] = "Coherent Read Own",
53         [0x09] = "Coherent Read Share",
54         [0x0a] = "Coherent Read Discard",
55         [0x0b] = "Coherent Ready Share Always",
56         [0x0c] = "Coherent Upgrade",
57         [0x0d] = "Coherent Writeback",
58         [0x0e] = "0x0e",
59         [0x0f] = "0x0f",
60         [0x10] = "Coherent Copyback",
61         [0x11] = "Coherent Copyback Invalidate",
62         [0x12] = "Coherent Invalidate",
63         [0x13] = "Coherent Write Invalidate",
64         [0x14] = "Coherent Completion Sync",
65         [0x15] = "0x15",
66         [0x16] = "0x16",
67         [0x17] = "0x17",
68         [0x18] = "0x18",
69         [0x19] = "0x19",
70         [0x1a] = "0x1a",
71         [0x1b] = "0x1b",
72         [0x1c] = "0x1c",
73         [0x1d] = "0x1d",
74         [0x1e] = "0x1e",
75         [0x1f] = "0x1f"
76 };
77
78 /* CM3 Tag ECC command type */
79 static char *cm3_cmd[16] = {
80         [0x0] = "Legacy Read",
81         [0x1] = "Legacy Write",
82         [0x2] = "Coherent Read Own",
83         [0x3] = "Coherent Read Share",
84         [0x4] = "Coherent Read Discard",
85         [0x5] = "Coherent Evicted",
86         [0x6] = "Coherent Upgrade",
87         [0x7] = "Coherent Upgrade for Store Conditional",
88         [0x8] = "Coherent Writeback",
89         [0x9] = "Coherent Write Invalidate",
90         [0xa] = "0xa",
91         [0xb] = "0xb",
92         [0xc] = "0xc",
93         [0xd] = "0xd",
94         [0xe] = "0xe",
95         [0xf] = "0xf"
96 };
97
98 /* CM3 Tag ECC command group */
99 static char *cm3_cmd_group[8] = {
100         [0x0] = "Normal",
101         [0x1] = "Registers",
102         [0x2] = "TLB",
103         [0x3] = "0x3",
104         [0x4] = "L1I",
105         [0x5] = "L1D",
106         [0x6] = "L3",
107         [0x7] = "L2"
108 };
109
110 static char *cm2_core[8] = {
111         "Invalid/OK",   "Invalid/Data",
112         "Shared/OK",    "Shared/Data",
113         "Modified/OK",  "Modified/Data",
114         "Exclusive/OK", "Exclusive/Data"
115 };
116
117 static char *cm2_l2_type[4] = {
118         [0x0] = "None",
119         [0x1] = "Tag RAM single/double ECC error",
120         [0x2] = "Data RAM single/double ECC error",
121         [0x3] = "WS RAM uncorrectable dirty parity"
122 };
123
124 static char *cm2_l2_instr[32] = {
125         [0x00] = "L2_NOP",
126         [0x01] = "L2_ERR_CORR",
127         [0x02] = "L2_TAG_INV",
128         [0x03] = "L2_WS_CLEAN",
129         [0x04] = "L2_RD_MDYFY_WR",
130         [0x05] = "L2_WS_MRU",
131         [0x06] = "L2_EVICT_LN2",
132         [0x07] = "0x07",
133         [0x08] = "L2_EVICT",
134         [0x09] = "L2_REFL",
135         [0x0a] = "L2_RD",
136         [0x0b] = "L2_WR",
137         [0x0c] = "L2_EVICT_MRU",
138         [0x0d] = "L2_SYNC",
139         [0x0e] = "L2_REFL_ERR",
140         [0x0f] = "0x0f",
141         [0x10] = "L2_INDX_WB_INV",
142         [0x11] = "L2_INDX_LD_TAG",
143         [0x12] = "L2_INDX_ST_TAG",
144         [0x13] = "L2_INDX_ST_DATA",
145         [0x14] = "L2_INDX_ST_ECC",
146         [0x15] = "0x15",
147         [0x16] = "0x16",
148         [0x17] = "0x17",
149         [0x18] = "L2_FTCH_AND_LCK",
150         [0x19] = "L2_HIT_INV",
151         [0x1a] = "L2_HIT_WB_INV",
152         [0x1b] = "L2_HIT_WB",
153         [0x1c] = "0x1c",
154         [0x1d] = "0x1d",
155         [0x1e] = "0x1e",
156         [0x1f] = "0x1f"
157 };
158
159 static char *cm2_causes[32] = {
160         "None", "GC_WR_ERR", "GC_RD_ERR", "COH_WR_ERR",
161         "COH_RD_ERR", "MMIO_WR_ERR", "MMIO_RD_ERR", "0x07",
162         "0x08", "0x09", "0x0a", "0x0b",
163         "0x0c", "0x0d", "0x0e", "0x0f",
164         "0x10", "INTVN_WR_ERR", "INTVN_RD_ERR", "0x13",
165         "0x14", "0x15", "0x16", "0x17",
166         "L2_RD_UNCORR", "L2_WR_UNCORR", "L2_CORR", "0x1b",
167         "0x1c", "0x1d", "0x1e", "0x1f"
168 };
169
170 static char *cm3_causes[32] = {
171         "0x0", "MP_CORRECTABLE_ECC_ERR", "MP_REQUEST_DECODE_ERR",
172         "MP_UNCORRECTABLE_ECC_ERR", "MP_PARITY_ERR", "MP_COHERENCE_ERR",
173         "CMBIU_REQUEST_DECODE_ERR", "CMBIU_PARITY_ERR", "CMBIU_AXI_RESP_ERR",
174         "0x9", "RBI_BUS_ERR", "0xb", "0xc", "0xd", "0xe", "0xf", "0x10",
175         "0x11", "0x12", "0x13", "0x14", "0x15", "0x16", "0x17", "0x18",
176         "0x19", "0x1a", "0x1b", "0x1c", "0x1d", "0x1e", "0x1f"
177 };
178
179 static DEFINE_PER_CPU_ALIGNED(spinlock_t, cm_core_lock);
180 static DEFINE_PER_CPU_ALIGNED(unsigned long, cm_core_lock_flags);
181
182 phys_addr_t __mips_cm_phys_base(void)
183 {
184         u32 config3 = read_c0_config3();
185         unsigned long cmgcr;
186
187         /* Check the CMGCRBase register is implemented */
188         if (!(config3 & MIPS_CONF3_CMGCR))
189                 return 0;
190
191         /* Read the address from CMGCRBase */
192         cmgcr = read_c0_cmgcrbase();
193         return (cmgcr & MIPS_CMGCRF_BASE) << (36 - 32);
194 }
195
196 phys_addr_t mips_cm_phys_base(void)
197         __attribute__((weak, alias("__mips_cm_phys_base")));
198
199 phys_addr_t __mips_cm_l2sync_phys_base(void)
200 {
201         u32 base_reg;
202
203         /*
204          * If the L2-only sync region is already enabled then leave it at it's
205          * current location.
206          */
207         base_reg = read_gcr_l2_only_sync_base();
208         if (base_reg & CM_GCR_L2_ONLY_SYNC_BASE_SYNCEN)
209                 return base_reg & CM_GCR_L2_ONLY_SYNC_BASE_SYNCBASE;
210
211         /* Default to following the CM */
212         return mips_cm_phys_base() + MIPS_CM_GCR_SIZE;
213 }
214
215 phys_addr_t mips_cm_l2sync_phys_base(void)
216         __attribute__((weak, alias("__mips_cm_l2sync_phys_base")));
217
218 static void mips_cm_probe_l2sync(void)
219 {
220         unsigned major_rev;
221         phys_addr_t addr;
222
223         /* L2-only sync was introduced with CM major revision 6 */
224         major_rev = FIELD_GET(CM_GCR_REV_MAJOR, read_gcr_rev());
225         if (major_rev < 6)
226                 return;
227
228         /* Find a location for the L2 sync region */
229         addr = mips_cm_l2sync_phys_base();
230         BUG_ON((addr & CM_GCR_L2_ONLY_SYNC_BASE_SYNCBASE) != addr);
231         if (!addr)
232                 return;
233
234         /* Set the region base address & enable it */
235         write_gcr_l2_only_sync_base(addr | CM_GCR_L2_ONLY_SYNC_BASE_SYNCEN);
236
237         /* Map the region */
238         mips_cm_l2sync_base = ioremap(addr, MIPS_CM_L2SYNC_SIZE);
239 }
240
241 int mips_cm_probe(void)
242 {
243         phys_addr_t addr;
244         u32 base_reg;
245         unsigned cpu;
246
247         /*
248          * No need to probe again if we have already been
249          * here before.
250          */
251         if (mips_gcr_base)
252                 return 0;
253
254         addr = mips_cm_phys_base();
255         BUG_ON((addr & CM_GCR_BASE_GCRBASE) != addr);
256         if (!addr)
257                 return -ENODEV;
258
259         mips_gcr_base = ioremap(addr, MIPS_CM_GCR_SIZE);
260         if (!mips_gcr_base)
261                 return -ENXIO;
262
263         /* sanity check that we're looking at a CM */
264         base_reg = read_gcr_base();
265         if ((base_reg & CM_GCR_BASE_GCRBASE) != addr) {
266                 pr_err("GCRs appear to have been moved (expected them at 0x%08lx)!\n",
267                        (unsigned long)addr);
268                 iounmap(mips_gcr_base);
269                 mips_gcr_base = NULL;
270                 return -ENODEV;
271         }
272
273         /* set default target to memory */
274         change_gcr_base(CM_GCR_BASE_CMDEFTGT, CM_GCR_BASE_CMDEFTGT_MEM);
275
276         /* disable CM regions */
277         write_gcr_reg0_base(CM_GCR_REGn_BASE_BASEADDR);
278         write_gcr_reg0_mask(CM_GCR_REGn_MASK_ADDRMASK);
279         write_gcr_reg1_base(CM_GCR_REGn_BASE_BASEADDR);
280         write_gcr_reg1_mask(CM_GCR_REGn_MASK_ADDRMASK);
281         write_gcr_reg2_base(CM_GCR_REGn_BASE_BASEADDR);
282         write_gcr_reg2_mask(CM_GCR_REGn_MASK_ADDRMASK);
283         write_gcr_reg3_base(CM_GCR_REGn_BASE_BASEADDR);
284         write_gcr_reg3_mask(CM_GCR_REGn_MASK_ADDRMASK);
285
286         /* probe for an L2-only sync region */
287         mips_cm_probe_l2sync();
288
289         /* determine register width for this CM */
290         mips_cm_is64 = IS_ENABLED(CONFIG_64BIT) && (mips_cm_revision() >= CM_REV_CM3);
291
292         for_each_possible_cpu(cpu)
293                 spin_lock_init(&per_cpu(cm_core_lock, cpu));
294
295         return 0;
296 }
297
298 void mips_cm_lock_other(unsigned int cluster, unsigned int core,
299                         unsigned int vp, unsigned int block)
300 {
301         unsigned int curr_core, cm_rev;
302         u32 val;
303
304         cm_rev = mips_cm_revision();
305         preempt_disable();
306
307         if (cm_rev >= CM_REV_CM3) {
308                 val = FIELD_PREP(CM3_GCR_Cx_OTHER_CORE, core) |
309                       FIELD_PREP(CM3_GCR_Cx_OTHER_VP, vp);
310
311                 if (cm_rev >= CM_REV_CM3_5) {
312                         val |= CM_GCR_Cx_OTHER_CLUSTER_EN;
313                         val |= FIELD_PREP(CM_GCR_Cx_OTHER_CLUSTER, cluster);
314                         val |= FIELD_PREP(CM_GCR_Cx_OTHER_BLOCK, block);
315                 } else {
316                         WARN_ON(cluster != 0);
317                         WARN_ON(block != CM_GCR_Cx_OTHER_BLOCK_LOCAL);
318                 }
319
320                 /*
321                  * We need to disable interrupts in SMP systems in order to
322                  * ensure that we don't interrupt the caller with code which
323                  * may modify the redirect register. We do so here in a
324                  * slightly obscure way by using a spin lock, since this has
325                  * the neat property of also catching any nested uses of
326                  * mips_cm_lock_other() leading to a deadlock or a nice warning
327                  * with lockdep enabled.
328                  */
329                 spin_lock_irqsave(this_cpu_ptr(&cm_core_lock),
330                                   *this_cpu_ptr(&cm_core_lock_flags));
331         } else {
332                 WARN_ON(cluster != 0);
333                 WARN_ON(block != CM_GCR_Cx_OTHER_BLOCK_LOCAL);
334
335                 /*
336                  * We only have a GCR_CL_OTHER per core in systems with
337                  * CM 2.5 & older, so have to ensure other VP(E)s don't
338                  * race with us.
339                  */
340                 curr_core = cpu_core(&current_cpu_data);
341                 spin_lock_irqsave(&per_cpu(cm_core_lock, curr_core),
342                                   per_cpu(cm_core_lock_flags, curr_core));
343
344                 val = FIELD_PREP(CM_GCR_Cx_OTHER_CORENUM, core);
345         }
346
347         write_gcr_cl_other(val);
348
349         /*
350          * Ensure the core-other region reflects the appropriate core &
351          * VP before any accesses to it occur.
352          */
353         mb();
354 }
355
356 void mips_cm_unlock_other(void)
357 {
358         unsigned int curr_core;
359
360         if (mips_cm_revision() < CM_REV_CM3) {
361                 curr_core = cpu_core(&current_cpu_data);
362                 spin_unlock_irqrestore(&per_cpu(cm_core_lock, curr_core),
363                                        per_cpu(cm_core_lock_flags, curr_core));
364         } else {
365                 spin_unlock_irqrestore(this_cpu_ptr(&cm_core_lock),
366                                        *this_cpu_ptr(&cm_core_lock_flags));
367         }
368
369         preempt_enable();
370 }
371
372 void mips_cm_error_report(void)
373 {
374         u64 cm_error, cm_addr, cm_other;
375         unsigned long revision;
376         int ocause, cause;
377         char buf[256];
378
379         if (!mips_cm_present())
380                 return;
381
382         revision = mips_cm_revision();
383         cm_error = read_gcr_error_cause();
384         cm_addr = read_gcr_error_addr();
385         cm_other = read_gcr_error_mult();
386
387         if (revision < CM_REV_CM3) { /* CM2 */
388                 cause = FIELD_GET(CM_GCR_ERROR_CAUSE_ERRTYPE, cm_error);
389                 ocause = FIELD_GET(CM_GCR_ERROR_MULT_ERR2ND, cm_other);
390
391                 if (!cause)
392                         return;
393
394                 if (cause < 16) {
395                         unsigned long cca_bits = (cm_error >> 15) & 7;
396                         unsigned long tr_bits = (cm_error >> 12) & 7;
397                         unsigned long cmd_bits = (cm_error >> 7) & 0x1f;
398                         unsigned long stag_bits = (cm_error >> 3) & 15;
399                         unsigned long sport_bits = (cm_error >> 0) & 7;
400
401                         snprintf(buf, sizeof(buf),
402                                  "CCA=%lu TR=%s MCmd=%s STag=%lu "
403                                  "SPort=%lu\n", cca_bits, cm2_tr[tr_bits],
404                                  cm2_cmd[cmd_bits], stag_bits, sport_bits);
405                 } else if (cause < 24) {
406                         /* glob state & sresp together */
407                         unsigned long c3_bits = (cm_error >> 18) & 7;
408                         unsigned long c2_bits = (cm_error >> 15) & 7;
409                         unsigned long c1_bits = (cm_error >> 12) & 7;
410                         unsigned long c0_bits = (cm_error >> 9) & 7;
411                         unsigned long sc_bit = (cm_error >> 8) & 1;
412                         unsigned long cmd_bits = (cm_error >> 3) & 0x1f;
413                         unsigned long sport_bits = (cm_error >> 0) & 7;
414
415                         snprintf(buf, sizeof(buf),
416                                  "C3=%s C2=%s C1=%s C0=%s SC=%s "
417                                  "MCmd=%s SPort=%lu\n",
418                                  cm2_core[c3_bits], cm2_core[c2_bits],
419                                  cm2_core[c1_bits], cm2_core[c0_bits],
420                                  sc_bit ? "True" : "False",
421                                  cm2_cmd[cmd_bits], sport_bits);
422                 } else {
423                         unsigned long muc_bit = (cm_error >> 23) & 1;
424                         unsigned long ins_bits = (cm_error >> 18) & 0x1f;
425                         unsigned long arr_bits = (cm_error >> 16) & 3;
426                         unsigned long dw_bits = (cm_error >> 12) & 15;
427                         unsigned long way_bits = (cm_error >> 9) & 7;
428                         unsigned long mway_bit = (cm_error >> 8) & 1;
429                         unsigned long syn_bits = (cm_error >> 0) & 0xFF;
430
431                         snprintf(buf, sizeof(buf),
432                                  "Type=%s%s Instr=%s DW=%lu Way=%lu "
433                                  "MWay=%s Syndrome=0x%02lx",
434                                  muc_bit ? "Multi-UC " : "",
435                                  cm2_l2_type[arr_bits],
436                                  cm2_l2_instr[ins_bits], dw_bits, way_bits,
437                                  mway_bit ? "True" : "False", syn_bits);
438                 }
439                 pr_err("CM_ERROR=%08llx %s <%s>\n", cm_error,
440                        cm2_causes[cause], buf);
441                 pr_err("CM_ADDR =%08llx\n", cm_addr);
442                 pr_err("CM_OTHER=%08llx %s\n", cm_other, cm2_causes[ocause]);
443         } else { /* CM3 */
444                 ulong core_id_bits, vp_id_bits, cmd_bits, cmd_group_bits;
445                 ulong cm3_cca_bits, mcp_bits, cm3_tr_bits, sched_bit;
446
447                 cause = FIELD_GET(CM3_GCR_ERROR_CAUSE_ERRTYPE, cm_error);
448                 ocause = FIELD_GET(CM_GCR_ERROR_MULT_ERR2ND, cm_other);
449
450                 if (!cause)
451                         return;
452
453                 /* Used by cause == {1,2,3} */
454                 core_id_bits = (cm_error >> 22) & 0xf;
455                 vp_id_bits = (cm_error >> 18) & 0xf;
456                 cmd_bits = (cm_error >> 14) & 0xf;
457                 cmd_group_bits = (cm_error >> 11) & 0xf;
458                 cm3_cca_bits = (cm_error >> 8) & 7;
459                 mcp_bits = (cm_error >> 5) & 0xf;
460                 cm3_tr_bits = (cm_error >> 1) & 0xf;
461                 sched_bit = cm_error & 0x1;
462
463                 if (cause == 1 || cause == 3) { /* Tag ECC */
464                         unsigned long tag_ecc = (cm_error >> 57) & 0x1;
465                         unsigned long tag_way_bits = (cm_error >> 29) & 0xffff;
466                         unsigned long dword_bits = (cm_error >> 49) & 0xff;
467                         unsigned long data_way_bits = (cm_error >> 45) & 0xf;
468                         unsigned long data_sets_bits = (cm_error >> 29) & 0xfff;
469                         unsigned long bank_bit = (cm_error >> 28) & 0x1;
470                         snprintf(buf, sizeof(buf),
471                                  "%s ECC Error: Way=%lu (DWORD=%lu, Sets=%lu)"
472                                  "Bank=%lu CoreID=%lu VPID=%lu Command=%s"
473                                  "Command Group=%s CCA=%lu MCP=%d"
474                                  "Transaction type=%s Scheduler=%lu\n",
475                                  tag_ecc ? "TAG" : "DATA",
476                                  tag_ecc ? (unsigned long)ffs(tag_way_bits) - 1 :
477                                  data_way_bits, bank_bit, dword_bits,
478                                  data_sets_bits,
479                                  core_id_bits, vp_id_bits,
480                                  cm3_cmd[cmd_bits],
481                                  cm3_cmd_group[cmd_group_bits],
482                                  cm3_cca_bits, 1 << mcp_bits,
483                                  cm3_tr[cm3_tr_bits], sched_bit);
484                 } else if (cause == 2) {
485                         unsigned long data_error_type = (cm_error >> 41) & 0xfff;
486                         unsigned long data_decode_cmd = (cm_error >> 37) & 0xf;
487                         unsigned long data_decode_group = (cm_error >> 34) & 0x7;
488                         unsigned long data_decode_destination_id = (cm_error >> 28) & 0x3f;
489
490                         snprintf(buf, sizeof(buf),
491                                  "Decode Request Error: Type=%lu, Command=%lu"
492                                  "Command Group=%lu Destination ID=%lu"
493                                  "CoreID=%lu VPID=%lu Command=%s"
494                                  "Command Group=%s CCA=%lu MCP=%d"
495                                  "Transaction type=%s Scheduler=%lu\n",
496                                  data_error_type, data_decode_cmd,
497                                  data_decode_group, data_decode_destination_id,
498                                  core_id_bits, vp_id_bits,
499                                  cm3_cmd[cmd_bits],
500                                  cm3_cmd_group[cmd_group_bits],
501                                  cm3_cca_bits, 1 << mcp_bits,
502                                  cm3_tr[cm3_tr_bits], sched_bit);
503                 } else {
504                         buf[0] = 0;
505                 }
506
507                 pr_err("CM_ERROR=%llx %s <%s>\n", cm_error,
508                        cm3_causes[cause], buf);
509                 pr_err("CM_ADDR =%llx\n", cm_addr);
510                 pr_err("CM_OTHER=%llx %s\n", cm_other, cm3_causes[ocause]);
511         }
512
513         /* reprime cause register */
514         write_gcr_error_cause(cm_error);
515 }