xref: /openbmc/linux/arch/powerpc/include/asm/head-64.h (revision 4da722ca)
1 #ifndef _ASM_POWERPC_HEAD_64_H
2 #define _ASM_POWERPC_HEAD_64_H
3 
4 #include <asm/cache.h>
5 
6 #ifdef __ASSEMBLY__
7 /*
8  * We can't do CPP stringification and concatination directly into the section
9  * name for some reason, so these macros can do it for us.
10  */
11 .macro define_ftsec name
12 	.section ".head.text.\name\()","ax",@progbits
13 .endm
14 .macro define_data_ftsec name
15 	.section ".head.data.\name\()","a",@progbits
16 .endm
17 .macro use_ftsec name
18 	.section ".head.text.\name\()"
19 .endm
20 
21 /*
22  * Fixed (location) sections are used by opening fixed sections and emitting
23  * fixed section entries into them before closing them. Multiple fixed sections
24  * can be open at any time.
25  *
26  * Each fixed section created in a .S file must have corresponding linkage
27  * directives including location, added to  arch/powerpc/kernel/vmlinux.lds.S
28  *
29  * For each fixed section, code is generated into it in the order which it
30  * appears in the source.  Fixed section entries can be placed at a fixed
31  * location within the section using _LOCATION postifx variants. These must
32  * be ordered according to their relative placements within the section.
33  *
34  * OPEN_FIXED_SECTION(section_name, start_address, end_address)
35  * FIXED_SECTION_ENTRY_BEGIN(section_name, label1)
36  *
37  * USE_FIXED_SECTION(section_name)
38  * label3:
39  *     li  r10,128
40  *     mv  r11,r10
41 
42  * FIXED_SECTION_ENTRY_BEGIN_LOCATION(section_name, label2, start_address, size)
43  * FIXED_SECTION_ENTRY_END_LOCATION(section_name, label2, start_address, size)
44  * CLOSE_FIXED_SECTION(section_name)
45  *
46  * ZERO_FIXED_SECTION can be used to emit zeroed data.
47  *
48  * Troubleshooting:
49  * - If the build dies with "Error: attempt to move .org backwards" at
50  *   CLOSE_FIXED_SECTION() or elsewhere, there may be something
51  *   unexpected being added there. Remove the '. = x_len' line, rebuild, and
52  *   check what is pushing the section down.
53  * - If the build dies in linking, check arch/powerpc/tools/head_check.sh
54  *   comments.
55  * - If the kernel crashes or hangs in very early boot, it could be linker
56  *   stubs at the start of the main text.
57  */
58 
59 #define OPEN_FIXED_SECTION(sname, start, end)			\
60 	sname##_start = (start);				\
61 	sname##_end = (end);					\
62 	sname##_len = (end) - (start);				\
63 	define_ftsec sname;					\
64 	. = 0x0;						\
65 start_##sname:
66 
67 /*
68  * .linker_stub_catch section is used to catch linker stubs from being
69  * inserted in our .text section, above the start_text label (which breaks
70  * the ABS_ADDR calculation). See kernel/vmlinux.lds.S and tools/head_check.sh
71  * for more details. We would prefer to just keep a cacheline (0x80), but
72  * 0x100 seems to be how the linker aligns branch stub groups.
73  */
74 #ifdef CONFIG_LD_HEAD_STUB_CATCH
75 #define OPEN_TEXT_SECTION(start)				\
76 	.section ".linker_stub_catch","ax",@progbits;		\
77 linker_stub_catch:						\
78 	. = 0x4;						\
79 	text_start = (start) + 0x100;				\
80 	.section ".text","ax",@progbits;			\
81 	.balign 0x100;						\
82 start_text:
83 #else
84 #define OPEN_TEXT_SECTION(start)				\
85 	text_start = (start);					\
86 	.section ".text","ax",@progbits;			\
87 	. = 0x0;						\
88 start_text:
89 #endif
90 
91 #define ZERO_FIXED_SECTION(sname, start, end)			\
92 	sname##_start = (start);				\
93 	sname##_end = (end);					\
94 	sname##_len = (end) - (start);				\
95 	define_data_ftsec sname;				\
96 	. = 0x0;						\
97 	. = sname##_len;
98 
99 #define USE_FIXED_SECTION(sname)				\
100 	fs_label = start_##sname;				\
101 	fs_start = sname##_start;				\
102 	use_ftsec sname;
103 
104 #define USE_TEXT_SECTION()					\
105 	fs_label = start_text;					\
106 	fs_start = text_start;					\
107 	.text
108 
109 #define CLOSE_FIXED_SECTION(sname)				\
110 	USE_FIXED_SECTION(sname);				\
111 	. = sname##_len;					\
112 end_##sname:
113 
114 
115 #define __FIXED_SECTION_ENTRY_BEGIN(sname, name, __align)	\
116 	USE_FIXED_SECTION(sname);				\
117 	.balign __align;					\
118 	.global name;						\
119 name:
120 
121 #define FIXED_SECTION_ENTRY_BEGIN(sname, name)			\
122 	__FIXED_SECTION_ENTRY_BEGIN(sname, name, IFETCH_ALIGN_BYTES)
123 
124 #define FIXED_SECTION_ENTRY_BEGIN_LOCATION(sname, name, start, size) \
125 	USE_FIXED_SECTION(sname);				\
126 	name##_start = (start);					\
127 	.if ((start) % (size) != 0);				\
128 	.error "Fixed section exception vector misalignment";	\
129 	.endif;							\
130 	.if ((size) != 0x20) && ((size) != 0x80) && ((size) != 0x100); \
131 	.error "Fixed section exception vector bad size";	\
132 	.endif;							\
133 	.if (start) < sname##_start;				\
134 	.error "Fixed section underflow";			\
135 	.abort;							\
136 	.endif;							\
137 	. = (start) - sname##_start;				\
138 	.global name;						\
139 name:
140 
141 #define FIXED_SECTION_ENTRY_END_LOCATION(sname, name, start, size) \
142 	.if (start) + (size) > sname##_end;			\
143 	.error "Fixed section overflow";			\
144 	.abort;							\
145 	.endif;							\
146 	.if (. - name > (start) + (size) - name##_start);	\
147 	.error "Fixed entry overflow";				\
148 	.abort;							\
149 	.endif;							\
150 	. = ((start) + (size) - sname##_start);			\
151 
152 
153 /*
154  * These macros are used to change symbols in other fixed sections to be
155  * absolute or related to our current fixed section.
156  *
157  * - DEFINE_FIXED_SYMBOL / FIXED_SYMBOL_ABS_ADDR is used to find the
158  *   absolute address of a symbol within a fixed section, from any section.
159  *
160  * - ABS_ADDR is used to find the absolute address of any symbol, from within
161  *   a fixed section.
162  */
163 #define DEFINE_FIXED_SYMBOL(label)				\
164 	label##_absolute = (label - fs_label + fs_start)
165 
166 #define FIXED_SYMBOL_ABS_ADDR(label)				\
167 	(label##_absolute)
168 
169 #define ABS_ADDR(label) (label - fs_label + fs_start)
170 
171 /*
172  * Following are the BOOK3S exception handler helper macros.
173  * Handlers come in a number of types, and each type has a number of varieties.
174  *
175  * EXC_REAL_*     - real, unrelocated exception vectors
176  * EXC_VIRT_*     - virt (AIL), unrelocated exception vectors
177  * TRAMP_REAL_*   - real, unrelocated helpers (virt can call these)
178  * TRAMP_VIRT_*   - virt, unreloc helpers (in practice, real can use)
179  * TRAMP_KVM      - KVM handlers that get put into real, unrelocated
180  * EXC_COMMON_*   - virt, relocated common handlers
181  *
182  * The EXC handlers are given a name, and branch to name_common, or the
183  * appropriate KVM or masking function. Vector handler verieties are as
184  * follows:
185  *
186  * EXC_{REAL|VIRT}_BEGIN/END - used to open-code the exception
187  *
188  * EXC_{REAL|VIRT}  - standard exception
189  *
190  * EXC_{REAL|VIRT}_suffix
191  *     where _suffix is:
192  *   - _MASKABLE               - maskable exception
193  *   - _OOL                    - out of line with trampoline to common handler
194  *   - _HV                     - HV exception
195  *
196  * There can be combinations, e.g., EXC_VIRT_OOL_MASKABLE_HV
197  *
198  * The one unusual case is __EXC_REAL_OOL_HV_DIRECT, which is
199  * an OOL vector that branches to a specified handler rather than the usual
200  * trampoline that goes to common. It, and other underscore macros, should
201  * be used with care.
202  *
203  * KVM handlers come in the following verieties:
204  * TRAMP_KVM
205  * TRAMP_KVM_SKIP
206  * TRAMP_KVM_HV
207  * TRAMP_KVM_HV_SKIP
208  *
209  * COMMON handlers come in the following verieties:
210  * EXC_COMMON_BEGIN/END - used to open-code the handler
211  * EXC_COMMON
212  * EXC_COMMON_ASYNC
213  * EXC_COMMON_HV
214  *
215  * TRAMP_REAL and TRAMP_VIRT can be used with BEGIN/END. KVM
216  * and OOL handlers are implemented as types of TRAMP and TRAMP_VIRT handlers.
217  */
218 
219 #define EXC_REAL_BEGIN(name, start, size)			\
220 	FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##name, start, size)
221 
222 #define EXC_REAL_END(name, start, size)				\
223 	FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##name, start, size)
224 
225 #define EXC_VIRT_BEGIN(name, start, size)			\
226 	FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)
227 
228 #define EXC_VIRT_END(name, start, size)				\
229 	FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##name, start, size)
230 
231 #define EXC_COMMON_BEGIN(name)					\
232 	USE_TEXT_SECTION();					\
233 	.balign IFETCH_ALIGN_BYTES;				\
234 	.global name;						\
235 	_ASM_NOKPROBE_SYMBOL(name);				\
236 	DEFINE_FIXED_SYMBOL(name);				\
237 name:
238 
239 #define TRAMP_REAL_BEGIN(name)					\
240 	FIXED_SECTION_ENTRY_BEGIN(real_trampolines, name)
241 
242 #define TRAMP_VIRT_BEGIN(name)					\
243 	FIXED_SECTION_ENTRY_BEGIN(virt_trampolines, name)
244 
245 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
246 #define TRAMP_KVM_BEGIN(name)					\
247 	TRAMP_VIRT_BEGIN(name)
248 #else
249 #define TRAMP_KVM_BEGIN(name)
250 #endif
251 
252 #define EXC_REAL_NONE(start, size)				\
253 	FIXED_SECTION_ENTRY_BEGIN_LOCATION(real_vectors, exc_real_##start##_##unused, start, size); \
254 	FIXED_SECTION_ENTRY_END_LOCATION(real_vectors, exc_real_##start##_##unused, start, size)
255 
256 #define EXC_VIRT_NONE(start, size)				\
257 	FIXED_SECTION_ENTRY_BEGIN_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size); \
258 	FIXED_SECTION_ENTRY_END_LOCATION(virt_vectors, exc_virt_##start##_##unused, start, size);
259 
260 
261 #define EXC_REAL(name, start, size)					\
262 	EXC_REAL_BEGIN(name, start, size);				\
263 	STD_EXCEPTION_PSERIES(start, name##_common);			\
264 	EXC_REAL_END(name, start, size);
265 
266 #define EXC_VIRT(name, start, size, realvec)				\
267 	EXC_VIRT_BEGIN(name, start, size);				\
268 	STD_RELON_EXCEPTION_PSERIES(start, realvec, name##_common);	\
269 	EXC_VIRT_END(name, start, size);
270 
271 #define EXC_REAL_MASKABLE(name, start, size)				\
272 	EXC_REAL_BEGIN(name, start, size);				\
273 	MASKABLE_EXCEPTION_PSERIES(start, start, name##_common);	\
274 	EXC_REAL_END(name, start, size);
275 
276 #define EXC_VIRT_MASKABLE(name, start, size, realvec)			\
277 	EXC_VIRT_BEGIN(name, start, size);				\
278 	MASKABLE_RELON_EXCEPTION_PSERIES(start, realvec, name##_common); \
279 	EXC_VIRT_END(name, start, size);
280 
281 #define EXC_REAL_HV(name, start, size)					\
282 	EXC_REAL_BEGIN(name, start, size);				\
283 	STD_EXCEPTION_HV(start, start, name##_common);			\
284 	EXC_REAL_END(name, start, size);
285 
286 #define EXC_VIRT_HV(name, start, size, realvec)				\
287 	EXC_VIRT_BEGIN(name, start, size);				\
288 	STD_RELON_EXCEPTION_HV(start, realvec, name##_common);		\
289 	EXC_VIRT_END(name, start, size);
290 
291 #define __EXC_REAL_OOL(name, start, size)				\
292 	EXC_REAL_BEGIN(name, start, size);				\
293 	__OOL_EXCEPTION(start, label, tramp_real_##name);		\
294 	EXC_REAL_END(name, start, size);
295 
296 #define __TRAMP_REAL_OOL(name, vec)					\
297 	TRAMP_REAL_BEGIN(tramp_real_##name);				\
298 	STD_EXCEPTION_PSERIES_OOL(vec, name##_common);			\
299 
300 #define EXC_REAL_OOL(name, start, size)					\
301 	__EXC_REAL_OOL(name, start, size);				\
302 	__TRAMP_REAL_OOL(name, start);
303 
304 #define __EXC_REAL_OOL_MASKABLE(name, start, size)			\
305 	__EXC_REAL_OOL(name, start, size);
306 
307 #define __TRAMP_REAL_OOL_MASKABLE(name, vec)				\
308 	TRAMP_REAL_BEGIN(tramp_real_##name);				\
309 	MASKABLE_EXCEPTION_PSERIES_OOL(vec, name##_common);		\
310 
311 #define EXC_REAL_OOL_MASKABLE(name, start, size)			\
312 	__EXC_REAL_OOL_MASKABLE(name, start, size);			\
313 	__TRAMP_REAL_OOL_MASKABLE(name, start);
314 
315 #define __EXC_REAL_OOL_HV_DIRECT(name, start, size, handler)		\
316 	EXC_REAL_BEGIN(name, start, size);				\
317 	__OOL_EXCEPTION(start, label, handler);				\
318 	EXC_REAL_END(name, start, size);
319 
320 #define __EXC_REAL_OOL_HV(name, start, size)				\
321 	__EXC_REAL_OOL(name, start, size);
322 
323 #define __TRAMP_REAL_OOL_HV(name, vec)					\
324 	TRAMP_REAL_BEGIN(tramp_real_##name);				\
325 	STD_EXCEPTION_HV_OOL(vec, name##_common);			\
326 
327 #define EXC_REAL_OOL_HV(name, start, size)				\
328 	__EXC_REAL_OOL_HV(name, start, size);				\
329 	__TRAMP_REAL_OOL_HV(name, start);
330 
331 #define __EXC_REAL_OOL_MASKABLE_HV(name, start, size)			\
332 	__EXC_REAL_OOL(name, start, size);
333 
334 #define __TRAMP_REAL_OOL_MASKABLE_HV(name, vec)				\
335 	TRAMP_REAL_BEGIN(tramp_real_##name);				\
336 	MASKABLE_EXCEPTION_HV_OOL(vec, name##_common);			\
337 
338 #define EXC_REAL_OOL_MASKABLE_HV(name, start, size)			\
339 	__EXC_REAL_OOL_MASKABLE_HV(name, start, size);			\
340 	__TRAMP_REAL_OOL_MASKABLE_HV(name, start);
341 
342 #define __EXC_VIRT_OOL(name, start, size)				\
343 	EXC_VIRT_BEGIN(name, start, size);				\
344 	__OOL_EXCEPTION(start, label, tramp_virt_##name);		\
345 	EXC_VIRT_END(name, start, size);
346 
347 #define __TRAMP_VIRT_OOL(name, realvec)					\
348 	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
349 	STD_RELON_EXCEPTION_PSERIES_OOL(realvec, name##_common);	\
350 
351 #define EXC_VIRT_OOL(name, start, size, realvec)			\
352 	__EXC_VIRT_OOL(name, start, size);				\
353 	__TRAMP_VIRT_OOL(name, realvec);
354 
355 #define __EXC_VIRT_OOL_MASKABLE(name, start, size)			\
356 	__EXC_VIRT_OOL(name, start, size);
357 
358 #define __TRAMP_VIRT_OOL_MASKABLE(name, realvec)			\
359 	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
360 	MASKABLE_RELON_EXCEPTION_PSERIES_OOL(realvec, name##_common);	\
361 
362 #define EXC_VIRT_OOL_MASKABLE(name, start, size, realvec)		\
363 	__EXC_VIRT_OOL_MASKABLE(name, start, size);			\
364 	__TRAMP_VIRT_OOL_MASKABLE(name, realvec);
365 
366 #define __EXC_VIRT_OOL_HV(name, start, size)				\
367 	__EXC_VIRT_OOL(name, start, size);
368 
369 #define __TRAMP_VIRT_OOL_HV(name, realvec)				\
370 	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
371 	STD_RELON_EXCEPTION_HV_OOL(realvec, name##_common);		\
372 
373 #define EXC_VIRT_OOL_HV(name, start, size, realvec)			\
374 	__EXC_VIRT_OOL_HV(name, start, size);				\
375 	__TRAMP_VIRT_OOL_HV(name, realvec);
376 
377 #define __EXC_VIRT_OOL_MASKABLE_HV(name, start, size)			\
378 	__EXC_VIRT_OOL(name, start, size);
379 
380 #define __TRAMP_VIRT_OOL_MASKABLE_HV(name, realvec)			\
381 	TRAMP_VIRT_BEGIN(tramp_virt_##name);				\
382 	MASKABLE_RELON_EXCEPTION_HV_OOL(realvec, name##_common);	\
383 
384 #define EXC_VIRT_OOL_MASKABLE_HV(name, start, size, realvec)		\
385 	__EXC_VIRT_OOL_MASKABLE_HV(name, start, size);			\
386 	__TRAMP_VIRT_OOL_MASKABLE_HV(name, realvec);
387 
388 #define TRAMP_KVM(area, n)						\
389 	TRAMP_KVM_BEGIN(do_kvm_##n);					\
390 	KVM_HANDLER(area, EXC_STD, n);					\
391 
392 #define TRAMP_KVM_SKIP(area, n)						\
393 	TRAMP_KVM_BEGIN(do_kvm_##n);					\
394 	KVM_HANDLER_SKIP(area, EXC_STD, n);				\
395 
396 /*
397  * HV variant exceptions get the 0x2 bit added to their trap number.
398  */
399 #define TRAMP_KVM_HV(area, n)						\
400 	TRAMP_KVM_BEGIN(do_kvm_H##n);					\
401 	KVM_HANDLER(area, EXC_HV, n + 0x2);				\
402 
403 #define TRAMP_KVM_HV_SKIP(area, n)					\
404 	TRAMP_KVM_BEGIN(do_kvm_H##n);					\
405 	KVM_HANDLER_SKIP(area, EXC_HV, n + 0x2);			\
406 
407 #define EXC_COMMON(name, realvec, hdlr)					\
408 	EXC_COMMON_BEGIN(name);						\
409 	STD_EXCEPTION_COMMON(realvec, name, hdlr);			\
410 
411 #define EXC_COMMON_ASYNC(name, realvec, hdlr)				\
412 	EXC_COMMON_BEGIN(name);						\
413 	STD_EXCEPTION_COMMON_ASYNC(realvec, name, hdlr);		\
414 
415 #define EXC_COMMON_HV(name, realvec, hdlr)				\
416 	EXC_COMMON_BEGIN(name);						\
417 	STD_EXCEPTION_COMMON(realvec + 0x2, name, hdlr);		\
418 
419 #endif /* __ASSEMBLY__ */
420 
421 #endif	/* _ASM_POWERPC_HEAD_64_H */
422