summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/mce_power.c
blob: 2c647b1e62e4b82d1157b39ef4086e29e066667a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
/*
 * Machine check exception handling CPU-side for power7 and power8
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright 2013 IBM Corporation
 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
 */

#undef DEBUG
#define pr_fmt(fmt) "mce_power: " fmt

#include <linux/types.h>
#include <linux/ptrace.h>
#include <asm/mmu.h>
#include <asm/mce.h>
#include <asm/machdep.h>

static void flush_tlb_206(unsigned int num_sets, unsigned int action)
{
	unsigned long rb;
	unsigned int i;

	switch (action) {
	case TLB_INVAL_SCOPE_GLOBAL:
		rb = TLBIEL_INVAL_SET;
		break;
	case TLB_INVAL_SCOPE_LPID:
		rb = TLBIEL_INVAL_SET_LPID;
		break;
	default:
		BUG();
		break;
	}

	asm volatile("ptesync" : : : "memory");
	for (i = 0; i < num_sets; i++) {
		asm volatile("tlbiel %0" : : "r" (rb));
		rb += 1 << TLBIEL_INVAL_SET_SHIFT;
	}
	asm volatile("ptesync" : : : "memory");
}

/*
 * Generic routine to flush TLB on power7. This routine is used as
 * flush_tlb hook in cpu_spec for Power7 processor.
 *
 * action => TLB_INVAL_SCOPE_GLOBAL:  Invalidate all TLBs.
 *	     TLB_INVAL_SCOPE_LPID: Invalidate TLB for current LPID.
 */
void __flush_tlb_power7(unsigned int action)
{
	flush_tlb_206(POWER7_TLB_SETS, action);
}

/*
 * Generic routine to flush TLB on power8. This routine is used as
 * flush_tlb hook in cpu_spec for power8 processor.
 *
 * action => TLB_INVAL_SCOPE_GLOBAL:  Invalidate all TLBs.
 *	     TLB_INVAL_SCOPE_LPID: Invalidate TLB for current LPID.
 */
void __flush_tlb_power8(unsigned int action)
{
	flush_tlb_206(POWER8_TLB_SETS, action);
}

/* flush SLBs and reload */
static void flush_and_reload_slb(void)
{
	struct slb_shadow *slb;
	unsigned long i, n;

	/* Invalidate all SLBs */
	asm volatile("slbmte %0,%0; slbia" : : "r" (0));

#ifdef CONFIG_KVM_BOOK3S_HANDLER
	/*
	 * If machine check is hit when in guest or in transition, we will
	 * only flush the SLBs and continue.
	 */
	if (get_paca()->kvm_hstate.in_guest)
		return;
#endif

	/* For host kernel, reload the SLBs from shadow SLB buffer. */
	slb = get_slb_shadow();
	if (!slb)
		return;

	n = min_t(u32, be32_to_cpu(slb->persistent), SLB_MIN_SIZE);

	/* Load up the SLB entries from shadow SLB */
	for (i = 0; i < n; i++) {
		unsigned long rb = be64_to_cpu(slb->save_area[i].esid);
		unsigned long rs = be64_to_cpu(slb->save_area[i].vsid);

		rb = (rb & ~0xFFFul) | i;
		asm volatile("slbmte %0,%1" : : "r" (rs), "r" (rb));
	}
}

static long mce_handle_derror(uint64_t dsisr, uint64_t slb_error_bits)
{
	long handled = 1;

	/*
	 * flush and reload SLBs for SLB errors and flush TLBs for TLB errors.
	 * reset the error bits whenever we handle them so that at the end
	 * we can check whether we handled all of them or not.
	 * */
	if (dsisr & slb_error_bits) {
		flush_and_reload_slb();
		/* reset error bits */
		dsisr &= ~(slb_error_bits);
	}
	if (dsisr & P7_DSISR_MC_TLB_MULTIHIT_MFTLB) {
		if (cur_cpu_spec && cur_cpu_spec->flush_tlb)
			cur_cpu_spec->flush_tlb(TLB_INVAL_SCOPE_GLOBAL);
		/* reset error bits */
		dsisr &= ~P7_DSISR_MC_TLB_MULTIHIT_MFTLB;
	}
	/* Any other errors we don't understand? */
	if (dsisr & 0xffffffffUL)
		handled = 0;

	return handled;
}

static long mce_handle_derror_p7(uint64_t dsisr)
{
	return mce_handle_derror(dsisr, P7_DSISR_MC_SLB_ERRORS);
}

static long mce_handle_common_ierror(uint64_t srr1)
{
	long handled = 0;

	switch (P7_SRR1_MC_IFETCH(srr1)) {
	case 0:
		break;
	case P7_SRR1_MC_IFETCH_SLB_PARITY:
	case P7_SRR1_MC_IFETCH_SLB_MULTIHIT:
		/* flush and reload SLBs for SLB errors. */
		flush_and_reload_slb();
		handled = 1;
		break;
	case P7_SRR1_MC_IFETCH_TLB_MULTIHIT:
		if (cur_cpu_spec && cur_cpu_spec->flush_tlb) {
			cur_cpu_spec->flush_tlb(TLB_INVAL_SCOPE_GLOBAL);
			handled = 1;
		}
		break;
	default:
		break;
	}

	return handled;
}

static long mce_handle_ierror_p7(uint64_t srr1)
{
	long handled = 0;

	handled = mce_handle_common_ierror(srr1);

	if (P7_SRR1_MC_IFETCH(srr1) == P7_SRR1_MC_IFETCH_SLB_BOTH) {
		flush_and_reload_slb();
		handled = 1;
	}
	return handled;
}

static void mce_get_common_ierror(struct mce_error_info *mce_err, uint64_t srr1)
{
	switch (P7_SRR1_MC_IFETCH(srr1)) {
	case P7_SRR1_MC_IFETCH_SLB_PARITY:
		mce_err->error_type = MCE_ERROR_TYPE_SLB;
		mce_err->u.slb_error_type = MCE_SLB_ERROR_PARITY;
		break;
	case P7_SRR1_MC_IFETCH_SLB_MULTIHIT:
		mce_err->error_type = MCE_ERROR_TYPE_SLB;
		mce_err->u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
		break;
	case P7_SRR1_MC_IFETCH_TLB_MULTIHIT:
		mce_err->error_type = MCE_ERROR_TYPE_TLB;
		mce_err->u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
		break;
	case P7_SRR1_MC_IFETCH_UE:
	case P7_SRR1_MC_IFETCH_UE_IFU_INTERNAL:
		mce_err->error_type = MCE_ERROR_TYPE_UE;
		mce_err->u.ue_error_type = MCE_UE_ERROR_IFETCH;
		break;
	case P7_SRR1_MC_IFETCH_UE_TLB_RELOAD:
		mce_err->error_type = MCE_ERROR_TYPE_UE;
		mce_err->u.ue_error_type =
				MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
		break;
	}
}

static void mce_get_ierror_p7(struct mce_error_info *mce_err, uint64_t srr1)
{
	mce_get_common_ierror(mce_err, srr1);
	if (P7_SRR1_MC_IFETCH(srr1) == P7_SRR1_MC_IFETCH_SLB_BOTH) {
		mce_err->error_type = MCE_ERROR_TYPE_SLB;
		mce_err->u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
	}
}

static void mce_get_derror_p7(struct mce_error_info *mce_err, uint64_t dsisr)
{
	if (dsisr & P7_DSISR_MC_UE) {
		mce_err->error_type = MCE_ERROR_TYPE_UE;
		mce_err->u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
	} else if (dsisr & P7_DSISR_MC_UE_TABLEWALK) {
		mce_err->error_type = MCE_ERROR_TYPE_UE;
		mce_err->u.ue_error_type =
				MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
	} else if (dsisr & P7_DSISR_MC_ERAT_MULTIHIT) {
		mce_err->error_type = MCE_ERROR_TYPE_ERAT;
		mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
	} else if (dsisr & P7_DSISR_MC_SLB_MULTIHIT) {
		mce_err->error_type = MCE_ERROR_TYPE_SLB;
		mce_err->u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
	} else if (dsisr & P7_DSISR_MC_SLB_PARITY_MFSLB) {
		mce_err->error_type = MCE_ERROR_TYPE_SLB;
		mce_err->u.slb_error_type = MCE_SLB_ERROR_PARITY;
	} else if (dsisr & P7_DSISR_MC_TLB_MULTIHIT_MFTLB) {
		mce_err->error_type = MCE_ERROR_TYPE_TLB;
		mce_err->u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
	} else if (dsisr & P7_DSISR_MC_SLB_MULTIHIT_PARITY) {
		mce_err->error_type = MCE_ERROR_TYPE_SLB;
		mce_err->u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
	}
}

static long mce_handle_ue_error(struct pt_regs *regs)
{
	long handled = 0;

	/*
	 * On specific SCOM read via MMIO we may get a machine check
	 * exception with SRR0 pointing inside opal. If that is the
	 * case OPAL may have recovery address to re-read SCOM data in
	 * different way and hence we can recover from this MC.
	 */

	if (ppc_md.mce_check_early_recovery) {
		if (ppc_md.mce_check_early_recovery(regs))
			handled = 1;
	}
	return handled;
}

long __machine_check_early_realmode_p7(struct pt_regs *regs)
{
	uint64_t srr1, nip, addr;
	long handled = 1;
	struct mce_error_info mce_error_info = { 0 };

	srr1 = regs->msr;
	nip = regs->nip;

	/*
	 * Handle memory errors depending whether this was a load/store or
	 * ifetch exception. Also, populate the mce error_type and
	 * type-specific error_type from either SRR1 or DSISR, depending
	 * whether this was a load/store or ifetch exception
	 */
	if (P7_SRR1_MC_LOADSTORE(srr1)) {
		handled = mce_handle_derror_p7(regs->dsisr);
		mce_get_derror_p7(&mce_error_info, regs->dsisr);
		addr = regs->dar;
	} else {
		handled = mce_handle_ierror_p7(srr1);
		mce_get_ierror_p7(&mce_error_info, srr1);
		addr = regs->nip;
	}

	/* Handle UE error. */
	if (mce_error_info.error_type == MCE_ERROR_TYPE_UE)
		handled = mce_handle_ue_error(regs);

	save_mce_event(regs, handled, &mce_error_info, nip, addr);
	return handled;
}

static void mce_get_ierror_p8(struct mce_error_info *mce_err, uint64_t srr1)
{
	mce_get_common_ierror(mce_err, srr1);
	if (P7_SRR1_MC_IFETCH(srr1) == P8_SRR1_MC_IFETCH_ERAT_MULTIHIT) {
		mce_err->error_type = MCE_ERROR_TYPE_ERAT;
		mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
	}
}

static void mce_get_derror_p8(struct mce_error_info *mce_err, uint64_t dsisr)
{
	mce_get_derror_p7(mce_err, dsisr);
	if (dsisr & P8_DSISR_MC_ERAT_MULTIHIT_SEC) {
		mce_err->error_type = MCE_ERROR_TYPE_ERAT;
		mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
	}
}

static long mce_handle_ierror_p8(uint64_t srr1)
{
	long handled = 0;

	handled = mce_handle_common_ierror(srr1);

	if (P7_SRR1_MC_IFETCH(srr1) == P8_SRR1_MC_IFETCH_ERAT_MULTIHIT) {
		flush_and_reload_slb();
		handled = 1;
	}
	return handled;
}

static long mce_handle_derror_p8(uint64_t dsisr)
{
	return mce_handle_derror(dsisr, P8_DSISR_MC_SLB_ERRORS);
}

long __machine_check_early_realmode_p8(struct pt_regs *regs)
{
	uint64_t srr1, nip, addr;
	long handled = 1;
	struct mce_error_info mce_error_info = { 0 };

	srr1 = regs->msr;
	nip = regs->nip;

	if (P7_SRR1_MC_LOADSTORE(srr1)) {
		handled = mce_handle_derror_p8(regs->dsisr);
		mce_get_derror_p8(&mce_error_info, regs->dsisr);
		addr = regs->dar;
	} else {
		handled = mce_handle_ierror_p8(srr1);
		mce_get_ierror_p8(&mce_error_info, srr1);
		addr = regs->nip;
	}

	/* Handle UE error. */
	if (mce_error_info.error_type == MCE_ERROR_TYPE_UE)
		handled = mce_handle_ue_error(regs);

	save_mce_event(regs, handled, &mce_error_info, nip, addr);
	return handled;
}