summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/include/asm/head-64.h
blob: fdcff76e9a25a6095d44317a9074c5f420961fcf (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
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_HEAD_64_H
#define _ASM_POWERPC_HEAD_64_H

#include <asm/cache.h>

#ifdef __ASSEMBLY__
/*
 * We can't do CPP stringification and concatination directly into the section
 * name for some reason, so these macros can do it for us.
 */
.macro define_ftsec name
	.section ".head.text.\name\()","ax",@progbits
.endm
.macro define_data_ftsec name
	.section ".head.data.\name\()","a",@progbits
.endm
.macro use_ftsec name
	.section ".head.text.\name\()"
.endm

/*
 * Fixed (location) sections are used by opening fixed sections and emitting
 * fixed section entries into them before closing them. Multiple fixed sections
 * can be open at any time.
 *
 * Each fixed section created in a .S file must have corresponding linkage
 * directives including location, added to  arch/powerpc/kernel/vmlinux.lds.S
 *
 * For each fixed section, code is generated into it in the order which it
 * appears in the source.  Fixed section entries can be placed at a fixed
 * location within the section using _LOCATION postifx variants. These must
 * be ordered according to their relative placements within the section.
 *
 * OPEN_FIXED_SECTION(section_name, start_address, end_address)
 * FIXED_SECTION_ENTRY_BEGIN(section_name, label1)
 *
 * USE_FIXED_SECTION(section_name)
 * label3:
 *     li  r10,128
 *     mv  r11,r10

 * FIXED_SECTION_ENTRY_BEGIN_LOCATION(section_name, label2, start_address, size)
 * FIXED_SECTION_ENTRY_END_LOCATION(section_name, label2, start_address, size)
 * CLOSE_FIXED_SECTION(section_name)
 *
 * ZERO_FIXED_SECTION can be used to emit zeroed data.
 *
 * Troubleshooting:
 * - If the build dies with "Error: attempt to move .org backwards" at
 *   CLOSE_FIXED_SECTION() or elsewhere, there may be something
 *   unexpected being added there. Remove the '. = x_len' line, rebuild, and
 *   check what is pushing the section down.
 * - If the build dies in linking, check arch/powerpc/tools/head_check.sh
 *   comments.
 * - If the kernel crashes or hangs in very early boot, it could be linker
 *   stubs at the start of the main text.
 */

#define OPEN_FIXED_SECTION(sname, start, end)			\
	sname##_start = (start);				\
	sname##_end = (end);					\
	sname##_len = (end) - (start);				\
	define_ftsec sname;					\
	. = 0x0;						\
start_##sname:

/*
 * .linker_stub_catch section is used to catch linker stubs from being
 * inserted in our .text section, above the start_text label (which breaks
 * the ABS_ADDR calculation). See kernel/vmlinux.lds.S and tools/head_check.sh
 * for more details. We would prefer to just keep a cacheline (0x80), but
 * 0x100 seems to be how the linker aligns branch stub groups.
 */
#ifdef CONFIG_LD_HEAD_STUB_CATCH
#define OPEN_TEXT_SECTION(start)				\
	.section ".linker_stub_catch","ax",@progbits;		\
linker_stub_catch:						\
	. = 0x4;						\
	text_start = (start) + 0x100;				\
	.section ".text","ax",@progbits;			\
	.balign 0x100;						\
start_text:
#else
#define OPEN_TEXT_SECTION(start)				\
	text_start = (start);					\
	.section ".text","ax",@progbits;			\
	. = 0x0;						\
start_text:
#endif

#define ZERO_FIXED_SECTION(sname, start, end)			\
	sname##_start = (start);				\
	sname##_end = (end);					\
	sname##_len = (end) - (start);				\
	define_data_ftsec sname;				\
	. = 0x0;						\
	. = sname##_len;

#define USE_FIXED_SECTION(sname)				\
	fs_label = start_##sname;				\
	fs_start = sname##_start;				\
	use_ftsec sname;

#define USE_TEXT_SECTION()					\
	fs_label = start_text;					\
	fs_start = text_start;					\
	.text

#define CLOSE_FIXED_SECTION(sname)				\
	USE_FIXED_SECTION(sname);				\
	. = sname##_len;					\
end_##sname:


#define __FIXED_SECTION_ENTRY_BEGIN(sname, name, __align)	\
	USE_FIXED_SECTION(sname);				\
	.balign __align;					\
	.global name;						\
name:

#define FIXED_SECTION_ENTRY_BEGIN(sname, name)			\
	__FIXED_SECTION_ENTRY_BEGIN(sname, name, IFETCH_ALIGN_BYTES)

#define FIXED_SECTION_ENTRY_BEGIN_LOCATION(sname, name, start, size) \
	USE_FIXED_SECTION(sname);				\
	name##_start = (start);					\
	.if ((start) % (size) != 0);				\
	.error "Fixed section exception vector misalignment";	\
	.endif;							\
	.if ((size) != 0x20) && ((size) != 0x80) && ((size) != 0x100); \
	.error "Fixed section exception vector bad size";	\
	.endif;							\
	.if (start) < sname##_start;				\
	.error "Fixed section underflow";			\
	.abort;							\
	.endif;							\
	. = (start) - sname##_start;				\
	.global name;						\
name:

#define FIXED_SECTION_ENTRY_END_LOCATION(sname, name, start, size) \
	.if (start) + (size) > sname##_end;			\
	.error "Fixed section overflow";			\
	.abort;							\
	.endif;							\
	.if (. - name > (start) + (size) - name##_start);	\
	.error "Fixed entry overflow";				\
	.abort;							\
	.endif;							\
	. = ((start) + (size) - sname##_start);			\


/*
 * These macros are used to change symbols in other fixed sections to be
 * absolute or related to our current fixed section.
 *
 * - DEFINE_FIXED_SYMBOL / FIXED_SYMBOL_ABS_ADDR is used to find the
 *   absolute address of a symbol within a fixed section, from any section.
 *
 * - ABS_ADDR is used to find the absolute address of any symbol, from within
 *   a fixed section.
 */
#define DEFINE_FIXED_SYMBOL(label)				\
	label##_absolute = (label - fs_label + fs_start)

#define FIXED_SYMBOL_ABS_ADDR(label)				\
	(label##_absolute)

#define ABS_ADDR(label) (label - fs_label + fs_start)

/*
 * Following are the BOOK3S exception handler helper macros.
 * Handlers come in a number of types, and each type has a number of varieties.
 *
 * EXC_REAL_*     - real, unrelocated exception vectors
 * EXC_VIRT_*     - virt (AIL), unrelocated exception vectors
 * TRAMP_REAL_*   - real, unrelocated helpers (virt can call these)
 * TRAMP_VIRT_*   - virt, unreloc helpers (in practice, real can use)
 * TRAMP_KVM      - KVM handlers that get put into real, unrelocated
 * EXC_COMMON_*   - virt, relocated common handlers
 *
 * The EXC handlers are given a name, and branch to name_common, or the
 * appropriate KVM or masking function. Vector handler verieties are as
 * follows:
 *
 * EXC_{REAL|VIRT}_BEGIN/END - used to open-code the exception
 *
 * EXC_{REAL|VIRT}  - standard exception
 *
 * EXC_{REAL|VIRT}_suffix
 *     where _suffix is:
 *   - _MASKABLE               - maskable exception
 *   - _OOL                    - out of line with trampoline to common handler
 *   - _HV                     - HV exception
 *
 * There can be combinations, e.g., EXC_VIRT_OOL_MASKABLE_HV
 *
 * The one unusual case is __EXC_REAL_OOL_HV_DIRECT, which is
 * an OOL vector that branches to a specified handler rather than the usual
 * trampoline that goes to common. It, and other underscore macros, should
 * be used with care.
 *
 * KVM handlers come in the following verieties:
 * TRAMP_KVM
 * TRAMP_KVM_SKIP
 * TRAMP_KVM_HV
 * TRAMP_KVM_HV_SKIP
 *
 * COMMON handlers come in the following verieties:
 * EXC_COMMON_BEGIN/END - used to open-code the handler
 * EXC_COMMON
 * EXC_COMMON_ASYNC
 * EXC_COMMON_HV
 *
 * TRAMP_REAL and TRAMP_VIRT can be used with BEGIN/END. KVM
 * and OOL handlers are implemented as types of TRAMP and TRAMP_VIRT handlers.
 */

#define EXC_REAL_BEGIN(name, start, size)			\
	FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##name, start, size)

#define EXC_REAL_END(name, start, size)				\
	FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##name, start, size)

#define EXC_VIRT_BEGIN(name, start, size)			\
	FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)

#define EXC_VIRT_END(name, start, size)				\
	FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)

#define EXC_COMMON_BEGIN(name)					\
	USE_TEXT_SECTION();					\
	.balign IFETCH_ALIGN_BYTES;				\
	.global name;						\
	_ASM_NOKPROBE_SYMBOL(name);				\
	DEFINE_FIXED_SYMBOL(name);				\
name:

#define TRAMP_REAL_BEGIN(name)					\
	FIXED_SECTION_ENTRY_BEGIN(real_trampolines, name)

#define TRAMP_VIRT_BEGIN(name)					\
	FIXED_SECTION_ENTRY_BEGIN(virt_trampolines, name)

#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
#define TRAMP_KVM_BEGIN(name)					\
	TRAMP_VIRT_BEGIN(name)
#else
#define TRAMP_KVM_BEGIN(name)
#endif

#define EXC_REAL_NONE(start, size)				\
	FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##unused, start, size); \
	FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##unused, start, size)

#define EXC_VIRT_NONE(start, size)				\
	FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size); \
	FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size);


#define EXC_REAL(name, start, size)					\
	EXC_REAL_BEGIN(name, start, size);				\
	STD_EXCEPTION_PSERIES(start, name##_common);			\
	EXC_REAL_END(name, start, size);

#define EXC_VIRT(name, start, size, realvec)				\
	EXC_VIRT_BEGIN(name, start, size);				\
	STD_RELON_EXCEPTION_PSERIES(start, realvec, name##_common);	\
	EXC_VIRT_END(name, start, size);

#define EXC_REAL_MASKABLE(name, start, size)				\
	EXC_REAL_BEGIN(name, start, size);				\
	MASKABLE_EXCEPTION_PSERIES(start, start, name##_common);	\
	EXC_REAL_END(name, start, size);

#define EXC_VIRT_MASKABLE(name, start, size, realvec)			\
	EXC_VIRT_BEGIN(name, start, size);				\
	MASKABLE_RELON_EXCEPTION_PSERIES(start, realvec, name##_common); \
	EXC_VIRT_END(name, start, size);

#define EXC_REAL_HV(name, start, size)					\
	EXC_REAL_BEGIN(name, start, size);				\
	STD_EXCEPTION_HV(start, start, name##_common);			\
	EXC_REAL_END(name, start, size);

#define EXC_VIRT_HV(name, start, size, realvec)				\
	EXC_VIRT_BEGIN(name, start, size);				\
	STD_RELON_EXCEPTION_HV(start, realvec, name##_common);		\
	EXC_VIRT_END(name, start, size);

#define __EXC_REAL_OOL(name, start, size)				\
	EXC_REAL_BEGIN(name, start, size);				\
	__OOL_EXCEPTION(start, label, tramp_real_##name);		\
	EXC_REAL_END(name, start, size);

#define __TRAMP_REAL_OOL(name, vec)					\
	TRAMP_REAL_BEGIN(tramp_real_##name);				\
	STD_EXCEPTION_PSERIES_OOL(vec, name##_common);			\

#define EXC_REAL_OOL(name, start, size)					\
	__EXC_REAL_OOL(name, start, size);				\
	__TRAMP_REAL_OOL(name, start);

#define __EXC_REAL_OOL_MASKABLE(name, start, size)			\
	__EXC_REAL_OOL(name, start, size);

#define __TRAMP_REAL_OOL_MASKABLE(name, vec)				\
	TRAMP_REAL_BEGIN(tramp_real_##name);				\
	MASKABLE_EXCEPTION_PSERIES_OOL(vec, name##_common);		\

#define EXC_REAL_OOL_MASKABLE(name, start, size)			\
	__EXC_REAL_OOL_MASKABLE(name, start, size);			\
	__TRAMP_REAL_OOL_MASKABLE(name, start);

#define __EXC_REAL_OOL_HV_DIRECT(name, start, size, handler)		\
	EXC_REAL_BEGIN(name, start, size);				\
	__OOL_EXCEPTION(start, label, handler);				\
	EXC_REAL_END(name, start, size);

#define __EXC_REAL_OOL_HV(name, start, size)				\
	__EXC_REAL_OOL(name, start, size);

#define __TRAMP_REAL_OOL_HV(name, vec)					\
	TRAMP_REAL_BEGIN(tramp_real_##name);				\
	STD_EXCEPTION_HV_OOL(vec, name##_common);			\

#define EXC_REAL_OOL_HV(name, start, size)				\
	__EXC_REAL_OOL_HV(name, start, size);				\
	__TRAMP_REAL_OOL_HV(name, start);

#define __EXC_REAL_OOL_MASKABLE_HV(name, start, size)			\
	__EXC_REAL_OOL(name, start, size);

#define __TRAMP_REAL_OOL_MASKABLE_HV(name, vec)				\
	TRAMP_REAL_BEGIN(tramp_real_##name);				\
	MASKABLE_EXCEPTION_HV_OOL(vec, name##_common);			\

#define EXC_REAL_OOL_MASKABLE_HV(name, start, size)			\
	__EXC_REAL_OOL_MASKABLE_HV(name, start, size);			\
	__TRAMP_REAL_OOL_MASKABLE_HV(name, start);

#define __EXC_VIRT_OOL(name, start, size)				\
	EXC_VIRT_BEGIN(name, start, size);				\
	__OOL_EXCEPTION(start, label, tramp_virt_##name);		\
	EXC_VIRT_END(name, start, size);

#define __TRAMP_VIRT_OOL(name, realvec)					\
	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
	STD_RELON_EXCEPTION_PSERIES_OOL(realvec, name##_common);	\

#define EXC_VIRT_OOL(name, start, size, realvec)			\
	__EXC_VIRT_OOL(name, start, size);				\
	__TRAMP_VIRT_OOL(name, realvec);

#define __EXC_VIRT_OOL_MASKABLE(name, start, size)			\
	__EXC_VIRT_OOL(name, start, size);

#define __TRAMP_VIRT_OOL_MASKABLE(name, realvec)			\
	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
	MASKABLE_RELON_EXCEPTION_PSERIES_OOL(realvec, name##_common);	\

#define EXC_VIRT_OOL_MASKABLE(name, start, size, realvec)		\
	__EXC_VIRT_OOL_MASKABLE(name, start, size);			\
	__TRAMP_VIRT_OOL_MASKABLE(name, realvec);

#define __EXC_VIRT_OOL_HV(name, start, size)				\
	__EXC_VIRT_OOL(name, start, size);

#define __TRAMP_VIRT_OOL_HV(name, realvec)				\
	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
	STD_RELON_EXCEPTION_HV_OOL(realvec, name##_common);		\

#define EXC_VIRT_OOL_HV(name, start, size, realvec)			\
	__EXC_VIRT_OOL_HV(name, start, size);				\
	__TRAMP_VIRT_OOL_HV(name, realvec);

#define __EXC_VIRT_OOL_MASKABLE_HV(name, start, size)			\
	__EXC_VIRT_OOL(name, start, size);

#define __TRAMP_VIRT_OOL_MASKABLE_HV(name, realvec)			\
	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
	MASKABLE_RELON_EXCEPTION_HV_OOL(realvec, name##_common);	\

#define EXC_VIRT_OOL_MASKABLE_HV(name, start, size, realvec)		\
	__EXC_VIRT_OOL_MASKABLE_HV(name, start, size);			\
	__TRAMP_VIRT_OOL_MASKABLE_HV(name, realvec);

#define TRAMP_KVM(area, n)						\
	TRAMP_KVM_BEGIN(do_kvm_##n);					\
	KVM_HANDLER(area, EXC_STD, n);					\

#define TRAMP_KVM_SKIP(area, n)						\
	TRAMP_KVM_BEGIN(do_kvm_##n);					\
	KVM_HANDLER_SKIP(area, EXC_STD, n);				\

/*
 * HV variant exceptions get the 0x2 bit added to their trap number.
 */
#define TRAMP_KVM_HV(area, n)						\
	TRAMP_KVM_BEGIN(do_kvm_H##n);					\
	KVM_HANDLER(area, EXC_HV, n + 0x2);				\

#define TRAMP_KVM_HV_SKIP(area, n)					\
	TRAMP_KVM_BEGIN(do_kvm_H##n);					\
	KVM_HANDLER_SKIP(area, EXC_HV, n + 0x2);			\

#define EXC_COMMON(name, realvec, hdlr)					\
	EXC_COMMON_BEGIN(name);						\
	STD_EXCEPTION_COMMON(realvec, name, hdlr);			\

#define EXC_COMMON_ASYNC(name, realvec, hdlr)				\
	EXC_COMMON_BEGIN(name);						\
	STD_EXCEPTION_COMMON_ASYNC(realvec, name, hdlr);		\

#define EXC_COMMON_HV(name, realvec, hdlr)				\
	EXC_COMMON_BEGIN(name);						\
	STD_EXCEPTION_COMMON(realvec + 0x2, name, hdlr);		\

#endif /* __ASSEMBLY__ */

#endif	/* _ASM_POWERPC_HEAD_64_H */
OpenPOWER on IntegriCloud