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1da177e4 LT |
1 | /* |
2 | * linux/arch/mips/dec/ecc-berr.c | |
3 | * | |
4 | * Bus error event handling code for systems equipped with ECC | |
5 | * handling logic, i.e. DECstation/DECsystem 5000/200 (KN02), | |
6 | * 5000/240 (KN03), 5000/260 (KN05) and DECsystem 5900 (KN03), | |
7 | * 5900/260 (KN05) systems. | |
8 | * | |
64dac503 | 9 | * Copyright (c) 2003, 2005 Maciej W. Rozycki |
1da177e4 LT |
10 | * |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | */ | |
16 | ||
17 | #include <linux/init.h> | |
64dac503 | 18 | #include <linux/interrupt.h> |
1da177e4 LT |
19 | #include <linux/kernel.h> |
20 | #include <linux/sched.h> | |
1da177e4 LT |
21 | #include <linux/types.h> |
22 | ||
23 | #include <asm/addrspace.h> | |
24 | #include <asm/bootinfo.h> | |
25 | #include <asm/cpu.h> | |
6dab2f45 | 26 | #include <asm/irq_regs.h> |
1da177e4 | 27 | #include <asm/processor.h> |
49afb1f6 | 28 | #include <asm/ptrace.h> |
1da177e4 LT |
29 | #include <asm/system.h> |
30 | #include <asm/traps.h> | |
31 | ||
32 | #include <asm/dec/ecc.h> | |
33 | #include <asm/dec/kn02.h> | |
34 | #include <asm/dec/kn03.h> | |
35 | #include <asm/dec/kn05.h> | |
36 | ||
37 | static volatile u32 *kn0x_erraddr; | |
38 | static volatile u32 *kn0x_chksyn; | |
39 | ||
40 | static inline void dec_ecc_be_ack(void) | |
41 | { | |
42 | *kn0x_erraddr = 0; /* any write clears the IRQ */ | |
43 | iob(); | |
44 | } | |
45 | ||
46 | static int dec_ecc_be_backend(struct pt_regs *regs, int is_fixup, int invoker) | |
47 | { | |
48 | static const char excstr[] = "exception"; | |
49 | static const char intstr[] = "interrupt"; | |
50 | static const char cpustr[] = "CPU"; | |
51 | static const char dmastr[] = "DMA"; | |
52 | static const char readstr[] = "read"; | |
53 | static const char mreadstr[] = "memory read"; | |
54 | static const char writestr[] = "write"; | |
55 | static const char mwritstr[] = "partial memory write"; | |
56 | static const char timestr[] = "timeout"; | |
57 | static const char overstr[] = "overrun"; | |
58 | static const char eccstr[] = "ECC error"; | |
59 | ||
60 | const char *kind, *agent, *cycle, *event; | |
61 | const char *status = "", *xbit = "", *fmt = ""; | |
64dac503 | 62 | unsigned long address; |
1da177e4 LT |
63 | u16 syn = 0, sngl; |
64 | ||
65 | int i = 0; | |
66 | ||
67 | u32 erraddr = *kn0x_erraddr; | |
68 | u32 chksyn = *kn0x_chksyn; | |
69 | int action = MIPS_BE_FATAL; | |
70 | ||
64dac503 | 71 | /* For non-ECC ack ASAP, so that any subsequent errors get caught. */ |
1da177e4 LT |
72 | if ((erraddr & (KN0X_EAR_VALID | KN0X_EAR_ECCERR)) == KN0X_EAR_VALID) |
73 | dec_ecc_be_ack(); | |
74 | ||
75 | kind = invoker ? intstr : excstr; | |
76 | ||
77 | if (!(erraddr & KN0X_EAR_VALID)) { | |
78 | /* No idea what happened. */ | |
64dac503 | 79 | printk(KERN_ALERT "Unidentified bus error %s\n", kind); |
1da177e4 LT |
80 | return action; |
81 | } | |
82 | ||
83 | agent = (erraddr & KN0X_EAR_CPU) ? cpustr : dmastr; | |
84 | ||
85 | if (erraddr & KN0X_EAR_ECCERR) { | |
86 | /* An ECC error on a CPU or DMA transaction. */ | |
87 | cycle = (erraddr & KN0X_EAR_WRITE) ? mwritstr : mreadstr; | |
88 | event = eccstr; | |
89 | } else { | |
90 | /* A CPU timeout or a DMA overrun. */ | |
91 | cycle = (erraddr & KN0X_EAR_WRITE) ? writestr : readstr; | |
92 | event = (erraddr & KN0X_EAR_CPU) ? timestr : overstr; | |
93 | } | |
94 | ||
95 | address = erraddr & KN0X_EAR_ADDRESS; | |
96 | /* For ECC errors on reads adjust for MT pipelining. */ | |
97 | if ((erraddr & (KN0X_EAR_WRITE | KN0X_EAR_ECCERR)) == KN0X_EAR_ECCERR) | |
98 | address = (address & ~0xfffLL) | ((address - 5) & 0xfffLL); | |
99 | address <<= 2; | |
100 | ||
101 | /* Only CPU errors are fixable. */ | |
102 | if (erraddr & KN0X_EAR_CPU && is_fixup) | |
103 | action = MIPS_BE_FIXUP; | |
104 | ||
105 | if (erraddr & KN0X_EAR_ECCERR) { | |
106 | static const u8 data_sbit[32] = { | |
107 | 0x4f, 0x4a, 0x52, 0x54, 0x57, 0x58, 0x5b, 0x5d, | |
108 | 0x23, 0x25, 0x26, 0x29, 0x2a, 0x2c, 0x31, 0x34, | |
109 | 0x0e, 0x0b, 0x13, 0x15, 0x16, 0x19, 0x1a, 0x1c, | |
110 | 0x62, 0x64, 0x67, 0x68, 0x6b, 0x6d, 0x70, 0x75, | |
111 | }; | |
112 | static const u8 data_mbit[25] = { | |
113 | 0x07, 0x0d, 0x1f, | |
114 | 0x2f, 0x32, 0x37, 0x38, 0x3b, 0x3d, 0x3e, | |
115 | 0x43, 0x45, 0x46, 0x49, 0x4c, 0x51, 0x5e, | |
116 | 0x61, 0x6e, 0x73, 0x76, 0x79, 0x7a, 0x7c, 0x7f, | |
117 | }; | |
118 | static const char sbestr[] = "corrected single"; | |
119 | static const char dbestr[] = "uncorrectable double"; | |
120 | static const char mbestr[] = "uncorrectable multiple"; | |
121 | ||
122 | if (!(address & 0x4)) | |
123 | syn = chksyn; /* Low bank. */ | |
124 | else | |
125 | syn = chksyn >> 16; /* High bank. */ | |
126 | ||
127 | if (!(syn & KN0X_ESR_VLDLO)) { | |
128 | /* Ack now, no rewrite will happen. */ | |
129 | dec_ecc_be_ack(); | |
130 | ||
64dac503 | 131 | fmt = KERN_ALERT "%s" "invalid\n"; |
1da177e4 LT |
132 | } else { |
133 | sngl = syn & KN0X_ESR_SNGLO; | |
134 | syn &= KN0X_ESR_SYNLO; | |
135 | ||
136 | /* | |
137 | * Multibit errors may be tagged incorrectly; | |
138 | * check the syndrome explicitly. | |
139 | */ | |
140 | for (i = 0; i < 25; i++) | |
141 | if (syn == data_mbit[i]) | |
142 | break; | |
143 | ||
144 | if (i < 25) { | |
145 | status = mbestr; | |
146 | } else if (!sngl) { | |
147 | status = dbestr; | |
148 | } else { | |
3bd4c902 MR |
149 | volatile u32 *ptr = |
150 | (void *)CKSEG1ADDR(address); | |
1da177e4 LT |
151 | |
152 | *ptr = *ptr; /* Rewrite. */ | |
153 | iob(); | |
154 | ||
155 | status = sbestr; | |
156 | action = MIPS_BE_DISCARD; | |
157 | } | |
158 | ||
159 | /* Ack now, now we've rewritten (or not). */ | |
160 | dec_ecc_be_ack(); | |
161 | ||
162 | if (syn && syn == (syn & -syn)) { | |
163 | if (syn == 0x01) { | |
164 | fmt = KERN_ALERT "%s" | |
165 | "%#04x -- %s bit error " | |
64dac503 | 166 | "at check bit C%s\n"; |
1da177e4 LT |
167 | xbit = "X"; |
168 | } else { | |
169 | fmt = KERN_ALERT "%s" | |
170 | "%#04x -- %s bit error " | |
64dac503 | 171 | "at check bit C%s%u\n"; |
1da177e4 LT |
172 | } |
173 | i = syn >> 2; | |
174 | } else { | |
175 | for (i = 0; i < 32; i++) | |
176 | if (syn == data_sbit[i]) | |
177 | break; | |
178 | if (i < 32) | |
179 | fmt = KERN_ALERT "%s" | |
180 | "%#04x -- %s bit error " | |
64dac503 | 181 | "at data bit D%s%u\n"; |
1da177e4 LT |
182 | else |
183 | fmt = KERN_ALERT "%s" | |
64dac503 | 184 | "%#04x -- %s bit error\n"; |
1da177e4 LT |
185 | } |
186 | } | |
187 | } | |
188 | ||
189 | if (action != MIPS_BE_FIXUP) | |
64dac503 | 190 | printk(KERN_ALERT "Bus error %s: %s %s %s at %#010lx\n", |
1da177e4 LT |
191 | kind, agent, cycle, event, address); |
192 | ||
193 | if (action != MIPS_BE_FIXUP && erraddr & KN0X_EAR_ECCERR) | |
194 | printk(fmt, " ECC syndrome ", syn, status, xbit, i); | |
195 | ||
196 | return action; | |
197 | } | |
198 | ||
199 | int dec_ecc_be_handler(struct pt_regs *regs, int is_fixup) | |
200 | { | |
201 | return dec_ecc_be_backend(regs, is_fixup, 0); | |
202 | } | |
203 | ||
6dab2f45 | 204 | irqreturn_t dec_ecc_be_interrupt(int irq, void *dev_id) |
1da177e4 | 205 | { |
6dab2f45 RB |
206 | struct pt_regs *regs = get_irq_regs(); |
207 | ||
1da177e4 LT |
208 | int action = dec_ecc_be_backend(regs, 0, 1); |
209 | ||
210 | if (action == MIPS_BE_DISCARD) | |
68e4a86c | 211 | return IRQ_HANDLED; |
1da177e4 LT |
212 | |
213 | /* | |
64dac503 MR |
214 | * FIXME: Find the affected processes and kill them, otherwise |
215 | * we must die. | |
1da177e4 LT |
216 | * |
217 | * The interrupt is asynchronously delivered thus EPC and RA | |
218 | * may be irrelevant, but are printed for a reference. | |
219 | */ | |
220 | printk(KERN_ALERT "Fatal bus interrupt, epc == %08lx, ra == %08lx\n", | |
221 | regs->cp0_epc, regs->regs[31]); | |
222 | die("Unrecoverable bus error", regs); | |
223 | } | |
224 | ||
225 | ||
226 | /* | |
227 | * Initialization differs a bit between KN02 and KN03/KN05, so we | |
228 | * need two variants. Once set up, all systems can be handled the | |
229 | * same way. | |
230 | */ | |
231 | static inline void dec_kn02_be_init(void) | |
232 | { | |
a5fc9c0b | 233 | volatile u32 *csr = (void *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR); |
1da177e4 | 234 | |
a5fc9c0b MR |
235 | kn0x_erraddr = (void *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_ERRADDR); |
236 | kn0x_chksyn = (void *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_CHKSYN); | |
1da177e4 | 237 | |
1da177e4 | 238 | /* Preset write-only bits of the Control Register cache. */ |
64dac503 | 239 | cached_kn02_csr = *csr | KN02_CSR_LEDS; |
1da177e4 LT |
240 | |
241 | /* Set normal ECC detection and generation. */ | |
242 | cached_kn02_csr &= ~(KN02_CSR_DIAGCHK | KN02_CSR_DIAGGEN); | |
243 | /* Enable ECC correction. */ | |
244 | cached_kn02_csr |= KN02_CSR_CORRECT; | |
245 | *csr = cached_kn02_csr; | |
246 | iob(); | |
1da177e4 LT |
247 | } |
248 | ||
249 | static inline void dec_kn03_be_init(void) | |
250 | { | |
a5fc9c0b MR |
251 | volatile u32 *mcr = (void *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_MCR); |
252 | volatile u32 *mbcs = (void *)CKSEG1ADDR(KN4K_SLOT_BASE + KN4K_MB_CSR); | |
1da177e4 | 253 | |
a5fc9c0b MR |
254 | kn0x_erraddr = (void *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_ERRADDR); |
255 | kn0x_chksyn = (void *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_CHKSYN); | |
42a3b4f2 | 256 | |
1da177e4 LT |
257 | /* |
258 | * Set normal ECC detection and generation, enable ECC correction. | |
259 | * For KN05 we also need to make sure EE (?) is enabled in the MB. | |
260 | * Otherwise DBE/IBE exceptions would be masked but bus error | |
261 | * interrupts would still arrive, resulting in an inevitable crash | |
262 | * if get_dbe() triggers one. | |
263 | */ | |
264 | *mcr = (*mcr & ~(KN03_MCR_DIAGCHK | KN03_MCR_DIAGGEN)) | | |
265 | KN03_MCR_CORRECT; | |
266 | if (current_cpu_data.cputype == CPU_R4400SC) | |
64dac503 | 267 | *mbcs |= KN4K_MB_CSR_EE; |
1da177e4 LT |
268 | fast_iob(); |
269 | } | |
270 | ||
271 | void __init dec_ecc_be_init(void) | |
272 | { | |
273 | if (mips_machtype == MACH_DS5000_200) | |
274 | dec_kn02_be_init(); | |
275 | else | |
276 | dec_kn03_be_init(); | |
277 | ||
278 | /* Clear any leftover errors from the firmware. */ | |
279 | dec_ecc_be_ack(); | |
280 | } |