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14cf11af 1/*
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2 * PowerPC version
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
6 * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
7 * Adapted for Power Macintosh by Paul Mackerras.
8 * Low-level exception handlers and MMU support
9 * rewritten by Paul Mackerras.
10 * Copyright (C) 1996 Paul Mackerras.
11 *
12 * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
13 * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
14 *
0ebc4cda
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15 * This file contains the entry point for the 64-bit kernel along
16 * with some early initialization code common to all 64-bit powerpc
17 * variants.
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18 *
19 * This program is free software; you can redistribute it and/or
20 * modify it under the terms of the GNU General Public License
21 * as published by the Free Software Foundation; either version
22 * 2 of the License, or (at your option) any later version.
23 */
24
14cf11af 25#include <linux/threads.h>
b5bbeb23 26#include <asm/reg.h>
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27#include <asm/page.h>
28#include <asm/mmu.h>
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29#include <asm/ppc_asm.h>
30#include <asm/asm-offsets.h>
31#include <asm/bug.h>
32#include <asm/cputable.h>
33#include <asm/setup.h>
34#include <asm/hvcall.h>
6cb7bfeb 35#include <asm/thread_info.h>
3f639ee8 36#include <asm/firmware.h>
16a15a30 37#include <asm/page_64.h>
945feb17 38#include <asm/irqflags.h>
2191d657 39#include <asm/kvm_book3s_asm.h>
46f52210 40#include <asm/ptrace.h>
7230c564 41#include <asm/hw_irq.h>
14cf11af 42
25985edc 43/* The physical memory is laid out such that the secondary processor
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44 * spin code sits at 0x0000...0x00ff. On server, the vectors follow
45 * using the layout described in exceptions-64s.S
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46 */
47
48/*
49 * Entering into this code we make the following assumptions:
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50 *
51 * For pSeries or server processors:
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52 * 1. The MMU is off & open firmware is running in real mode.
53 * 2. The kernel is entered at __start
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BH
54 * -or- For OPAL entry:
55 * 1. The MMU is off, processor in HV mode, primary CPU enters at 0
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56 * with device-tree in gpr3. We also get OPAL base in r8 and
57 * entry in r9 for debugging purposes
27f44888 58 * 2. Secondary processors enter at 0x60 with PIR in gpr3
14cf11af 59 *
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60 * For Book3E processors:
61 * 1. The MMU is on running in AS0 in a state defined in ePAPR
62 * 2. The kernel is entered at __start
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63 */
64
65 .text
66 .globl _stext
67_stext:
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68_GLOBAL(__start)
69 /* NOP this out unconditionally */
70BEGIN_FTR_SECTION
5c0484e2 71 FIXUP_ENDIAN
b85a046a 72 b .__start_initialization_multiplatform
14cf11af 73END_FTR_SECTION(0, 1)
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74
75 /* Catch branch to 0 in real mode */
76 trap
77
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78 /* Secondary processors spin on this value until it becomes nonzero.
79 * When it does it contains the real address of the descriptor
80 * of the function that the cpu should jump to to continue
81 * initialization.
82 */
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83 .globl __secondary_hold_spinloop
84__secondary_hold_spinloop:
85 .llong 0x0
86
87 /* Secondary processors write this value with their cpu # */
88 /* after they enter the spin loop immediately below. */
89 .globl __secondary_hold_acknowledge
90__secondary_hold_acknowledge:
91 .llong 0x0
92
928a3197 93#ifdef CONFIG_RELOCATABLE
8b8b0cc1
MM
94 /* This flag is set to 1 by a loader if the kernel should run
95 * at the loaded address instead of the linked address. This
96 * is used by kexec-tools to keep the the kdump kernel in the
97 * crash_kernel region. The loader is responsible for
98 * observing the alignment requirement.
99 */
100 /* Do not move this variable as kexec-tools knows about it. */
101 . = 0x5c
102 .globl __run_at_load
103__run_at_load:
104 .long 0x72756e30 /* "run0" -- relocate to 0 by default */
105#endif
106
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107 . = 0x60
108/*
75423b7b
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109 * The following code is used to hold secondary processors
110 * in a spin loop after they have entered the kernel, but
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111 * before the bulk of the kernel has been relocated. This code
112 * is relocated to physical address 0x60 before prom_init is run.
113 * All of it must fit below the first exception vector at 0x100.
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114 * Use .globl here not _GLOBAL because we want __secondary_hold
115 * to be the actual text address, not a descriptor.
14cf11af 116 */
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117 .globl __secondary_hold
118__secondary_hold:
5c0484e2 119 FIXUP_ENDIAN
2d27cfd3 120#ifndef CONFIG_PPC_BOOK3E
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121 mfmsr r24
122 ori r24,r24,MSR_RI
123 mtmsrd r24 /* RI on */
2d27cfd3 124#endif
f1870f77 125 /* Grab our physical cpu number */
14cf11af 126 mr r24,r3
96f013fe
JX
127 /* stash r4 for book3e */
128 mr r25,r4
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129
130 /* Tell the master cpu we're here */
131 /* Relocation is off & we are located at an address less */
132 /* than 0x100, so only need to grab low order offset. */
e31aa453 133 std r24,__secondary_hold_acknowledge-_stext(0)
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134 sync
135
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136 li r26,0
137#ifdef CONFIG_PPC_BOOK3E
138 tovirt(r26,r26)
139#endif
14cf11af 140 /* All secondary cpus wait here until told to start. */
96f013fe 141100: ld r4,__secondary_hold_spinloop-_stext(r26)
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142 cmpdi 0,r4,0
143 beq 100b
14cf11af 144
f1870f77 145#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
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146#ifdef CONFIG_PPC_BOOK3E
147 tovirt(r4,r4)
148#endif
1f6a93e4 149 ld r4,0(r4) /* deref function descriptor */
758438a7 150 mtctr r4
14cf11af 151 mr r3,r24
96f013fe
JX
152 /*
153 * it may be the case that other platforms have r4 right to
154 * begin with, this gives us some safety in case it is not
155 */
156#ifdef CONFIG_PPC_BOOK3E
157 mr r4,r25
158#else
2d27cfd3 159 li r4,0
96f013fe 160#endif
dd797738
BH
161 /* Make sure that patched code is visible */
162 isync
758438a7 163 bctr
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164#else
165 BUG_OPCODE
166#endif
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167
168/* This value is used to mark exception frames on the stack. */
169 .section ".toc","aw"
170exception_marker:
171 .tc ID_72656773_68657265[TC],0x7265677368657265
172 .text
173
14cf11af 174/*
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175 * On server, we include the exception vectors code here as it
176 * relies on absolute addressing which is only possible within
177 * this compilation unit
3c726f8d 178 */
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179#ifdef CONFIG_PPC_BOOK3S
180#include "exceptions-64s.S"
1f6a93e4 181#endif
3c726f8d 182
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183_GLOBAL(generic_secondary_thread_init)
184 mr r24,r3
185
186 /* turn on 64-bit mode */
187 bl .enable_64b_mode
188
189 /* get a valid TOC pointer, wherever we're mapped at */
190 bl .relative_toc
1fbe9cf2 191 tovirt(r2,r2)
2d27cfd3
BH
192
193#ifdef CONFIG_PPC_BOOK3E
194 /* Book3E initialization */
195 mr r3,r24
196 bl .book3e_secondary_thread_init
197#endif
198 b generic_secondary_common_init
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199
200/*
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201 * On pSeries and most other platforms, secondary processors spin
202 * in the following code.
14cf11af 203 * At entry, r3 = this processor's number (physical cpu id)
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204 *
205 * On Book3E, r4 = 1 to indicate that the initial TLB entry for
206 * this core already exists (setup via some other mechanism such
207 * as SCOM before entry).
14cf11af 208 */
f39b7a55 209_GLOBAL(generic_secondary_smp_init)
5c0484e2 210 FIXUP_ENDIAN
14cf11af 211 mr r24,r3
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212 mr r25,r4
213
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214 /* turn on 64-bit mode */
215 bl .enable_64b_mode
14cf11af 216
2d27cfd3 217 /* get a valid TOC pointer, wherever we're mapped at */
e31aa453 218 bl .relative_toc
1fbe9cf2 219 tovirt(r2,r2)
e31aa453 220
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BH
221#ifdef CONFIG_PPC_BOOK3E
222 /* Book3E initialization */
223 mr r3,r24
224 mr r4,r25
225 bl .book3e_secondary_core_init
226#endif
227
228generic_secondary_common_init:
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229 /* Set up a paca value for this processor. Since we have the
230 * physical cpu id in r24, we need to search the pacas to find
231 * which logical id maps to our physical one.
232 */
1426d5a3
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233 LOAD_REG_ADDR(r13, paca) /* Load paca pointer */
234 ld r13,0(r13) /* Get base vaddr of paca array */
768d18ad
MM
235#ifndef CONFIG_SMP
236 addi r13,r13,PACA_SIZE /* know r13 if used accidentally */
237 b .kexec_wait /* wait for next kernel if !SMP */
238#else
239 LOAD_REG_ADDR(r7, nr_cpu_ids) /* Load nr_cpu_ids address */
240 lwz r7,0(r7) /* also the max paca allocated */
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241 li r5,0 /* logical cpu id */
2421: lhz r6,PACAHWCPUID(r13) /* Load HW procid from paca */
243 cmpw r6,r24 /* Compare to our id */
244 beq 2f
245 addi r13,r13,PACA_SIZE /* Loop to next PACA on miss */
246 addi r5,r5,1
768d18ad 247 cmpw r5,r7 /* Check if more pacas exist */
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248 blt 1b
249
250 mr r3,r24 /* not found, copy phys to r3 */
251 b .kexec_wait /* next kernel might do better */
252
2dd60d79 2532: SET_PACA(r13)
2d27cfd3
BH
254#ifdef CONFIG_PPC_BOOK3E
255 addi r12,r13,PACA_EXTLB /* and TLB exc frame in another */
256 mtspr SPRN_SPRG_TLB_EXFRAME,r12
257#endif
258
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259 /* From now on, r24 is expected to be logical cpuid */
260 mr r24,r5
b6f6b98a 261
f39b7a55 262 /* See if we need to call a cpu state restore handler */
e31aa453 263 LOAD_REG_ADDR(r23, cur_cpu_spec)
f39b7a55
OJ
264 ld r23,0(r23)
265 ld r23,CPU_SPEC_RESTORE(r23)
266 cmpdi 0,r23,0
9d07bc84 267 beq 3f
f39b7a55
OJ
268 ld r23,0(r23)
269 mtctr r23
270 bctrl
271
7ac87abb 2723: LOAD_REG_ADDR(r3, spinning_secondaries) /* Decrement spinning_secondaries */
9d07bc84
BH
273 lwarx r4,0,r3
274 subi r4,r4,1
275 stwcx. r4,0,r3
276 bne 3b
277 isync
278
2794: HMT_LOW
ad0693ee
BH
280 lbz r23,PACAPROCSTART(r13) /* Test if this processor should */
281 /* start. */
ad0693ee 282 cmpwi 0,r23,0
9d07bc84 283 beq 4b /* Loop until told to go */
ad0693ee
BH
284
285 sync /* order paca.run and cur_cpu_spec */
9d07bc84 286 isync /* In case code patching happened */
ad0693ee 287
9d07bc84 288 /* Create a temp kernel stack for use before relocation is on. */
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289 ld r1,PACAEMERGSP(r13)
290 subi r1,r1,STACK_FRAME_OVERHEAD
291
c705677e 292 b __secondary_start
768d18ad 293#endif /* SMP */
14cf11af 294
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295/*
296 * Turn the MMU off.
297 * Assumes we're mapped EA == RA if the MMU is on.
298 */
2d27cfd3 299#ifdef CONFIG_PPC_BOOK3S
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300_STATIC(__mmu_off)
301 mfmsr r3
302 andi. r0,r3,MSR_IR|MSR_DR
303 beqlr
e31aa453 304 mflr r4
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305 andc r3,r3,r0
306 mtspr SPRN_SRR0,r4
307 mtspr SPRN_SRR1,r3
308 sync
309 rfid
310 b . /* prevent speculative execution */
2d27cfd3 311#endif
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312
313
314/*
315 * Here is our main kernel entry point. We support currently 2 kind of entries
316 * depending on the value of r5.
317 *
318 * r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content
319 * in r3...r7
320 *
321 * r5 == NULL -> kexec style entry. r3 is a physical pointer to the
322 * DT block, r4 is a physical pointer to the kernel itself
323 *
324 */
325_GLOBAL(__start_initialization_multiplatform)
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326 /* Make sure we are running in 64 bits mode */
327 bl .enable_64b_mode
328
329 /* Get TOC pointer (current runtime address) */
330 bl .relative_toc
331
332 /* find out where we are now */
333 bcl 20,31,$+4
3340: mflr r26 /* r26 = runtime addr here */
335 addis r26,r26,(_stext - 0b)@ha
336 addi r26,r26,(_stext - 0b)@l /* current runtime base addr */
337
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338 /*
339 * Are we booted from a PROM Of-type client-interface ?
340 */
341 cmpldi cr0,r5,0
939e60f6
SR
342 beq 1f
343 b .__boot_from_prom /* yes -> prom */
3441:
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345 /* Save parameters */
346 mr r31,r3
347 mr r30,r4
daea1175
BH
348#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
349 /* Save OPAL entry */
350 mr r28,r8
351 mr r29,r9
352#endif
14cf11af 353
2d27cfd3
BH
354#ifdef CONFIG_PPC_BOOK3E
355 bl .start_initialization_book3e
356 b .__after_prom_start
357#else
14cf11af 358 /* Setup some critical 970 SPRs before switching MMU off */
f39b7a55
OJ
359 mfspr r0,SPRN_PVR
360 srwi r0,r0,16
361 cmpwi r0,0x39 /* 970 */
362 beq 1f
363 cmpwi r0,0x3c /* 970FX */
364 beq 1f
365 cmpwi r0,0x44 /* 970MP */
190a24f5
OJ
366 beq 1f
367 cmpwi r0,0x45 /* 970GX */
f39b7a55
OJ
368 bne 2f
3691: bl .__cpu_preinit_ppc970
3702:
14cf11af 371
e31aa453 372 /* Switch off MMU if not already off */
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373 bl .__mmu_off
374 b .__after_prom_start
2d27cfd3 375#endif /* CONFIG_PPC_BOOK3E */
14cf11af 376
939e60f6 377_INIT_STATIC(__boot_from_prom)
28794d34 378#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
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379 /* Save parameters */
380 mr r31,r3
381 mr r30,r4
382 mr r29,r5
383 mr r28,r6
384 mr r27,r7
385
6088857b
OH
386 /*
387 * Align the stack to 16-byte boundary
388 * Depending on the size and layout of the ELF sections in the initial
e31aa453 389 * boot binary, the stack pointer may be unaligned on PowerMac
6088857b 390 */
c05b4770
LT
391 rldicr r1,r1,0,59
392
549e8152
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393#ifdef CONFIG_RELOCATABLE
394 /* Relocate code for where we are now */
395 mr r3,r26
396 bl .relocate
397#endif
398
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399 /* Restore parameters */
400 mr r3,r31
401 mr r4,r30
402 mr r5,r29
403 mr r6,r28
404 mr r7,r27
405
406 /* Do all of the interaction with OF client interface */
549e8152 407 mr r8,r26
14cf11af 408 bl .prom_init
28794d34
BH
409#endif /* #CONFIG_PPC_OF_BOOT_TRAMPOLINE */
410
411 /* We never return. We also hit that trap if trying to boot
412 * from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */
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413 trap
414
14cf11af 415_STATIC(__after_prom_start)
549e8152
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416#ifdef CONFIG_RELOCATABLE
417 /* process relocations for the final address of the kernel */
418 lis r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
419 sldi r25,r25,32
8b8b0cc1 420 lwz r7,__run_at_load-_stext(r26)
928a3197 421 cmplwi cr0,r7,1 /* flagged to stay where we are ? */
54622f10
MK
422 bne 1f
423 add r25,r25,r26
54622f10 4241: mr r3,r25
549e8152
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425 bl .relocate
426#endif
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427
428/*
e31aa453 429 * We need to run with _stext at physical address PHYSICAL_START.
14cf11af
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430 * This will leave some code in the first 256B of
431 * real memory, which are reserved for software use.
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432 *
433 * Note: This process overwrites the OF exception vectors.
14cf11af 434 */
549e8152 435 li r3,0 /* target addr */
2d27cfd3
BH
436#ifdef CONFIG_PPC_BOOK3E
437 tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */
438#endif
549e8152 439 mr. r4,r26 /* In some cases the loader may */
e31aa453 440 beq 9f /* have already put us at zero */
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441 li r6,0x100 /* Start offset, the first 0x100 */
442 /* bytes were copied earlier. */
2d27cfd3
BH
443#ifdef CONFIG_PPC_BOOK3E
444 tovirt(r6,r6) /* on booke, we already run at PAGE_OFFSET */
445#endif
14cf11af 446
11ee7e99 447#ifdef CONFIG_RELOCATABLE
54622f10
MK
448/*
449 * Check if the kernel has to be running as relocatable kernel based on the
8b8b0cc1 450 * variable __run_at_load, if it is set the kernel is treated as relocatable
54622f10
MK
451 * kernel, otherwise it will be moved to PHYSICAL_START
452 */
8b8b0cc1
MM
453 lwz r7,__run_at_load-_stext(r26)
454 cmplwi cr0,r7,1
54622f10
MK
455 bne 3f
456
c1fb6816
MN
457 /* just copy interrupts */
458 LOAD_REG_IMMEDIATE(r5, __end_interrupts - _stext)
54622f10
MK
459 b 5f
4603:
461#endif
462 lis r5,(copy_to_here - _stext)@ha
463 addi r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
464
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465 bl .copy_and_flush /* copy the first n bytes */
466 /* this includes the code being */
467 /* executed here. */
e31aa453
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468 addis r8,r3,(4f - _stext)@ha /* Jump to the copy of this code */
469 addi r8,r8,(4f - _stext)@l /* that we just made */
470 mtctr r8
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471 bctr
472
286e4f90 473.balign 8
54622f10
MK
474p_end: .llong _end - _stext
475
e31aa453
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4764: /* Now copy the rest of the kernel up to _end */
477 addis r5,r26,(p_end - _stext)@ha
478 ld r5,(p_end - _stext)@l(r5) /* get _end */
54622f10 4795: bl .copy_and_flush /* copy the rest */
e31aa453
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480
4819: b .start_here_multiplatform
482
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483/*
484 * Copy routine used to copy the kernel to start at physical address 0
485 * and flush and invalidate the caches as needed.
486 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
487 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
488 *
489 * Note: this routine *only* clobbers r0, r6 and lr
490 */
491_GLOBAL(copy_and_flush)
492 addi r5,r5,-8
493 addi r6,r6,-8
5a2fe38d 4944: li r0,8 /* Use the smallest common */
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495 /* denominator cache line */
496 /* size. This results in */
497 /* extra cache line flushes */
498 /* but operation is correct. */
499 /* Can't get cache line size */
500 /* from NACA as it is being */
501 /* moved too. */
502
503 mtctr r0 /* put # words/line in ctr */
5043: addi r6,r6,8 /* copy a cache line */
505 ldx r0,r6,r4
506 stdx r0,r6,r3
507 bdnz 3b
508 dcbst r6,r3 /* write it to memory */
509 sync
510 icbi r6,r3 /* flush the icache line */
511 cmpld 0,r6,r5
512 blt 4b
513 sync
514 addi r5,r5,8
515 addi r6,r6,8
29ce3c50 516 isync
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517 blr
518
519.align 8
520copy_to_here:
521
522#ifdef CONFIG_SMP
523#ifdef CONFIG_PPC_PMAC
524/*
525 * On PowerMac, secondary processors starts from the reset vector, which
526 * is temporarily turned into a call to one of the functions below.
527 */
528 .section ".text";
529 .align 2 ;
530
35499c01
PM
531 .globl __secondary_start_pmac_0
532__secondary_start_pmac_0:
533 /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
534 li r24,0
535 b 1f
536 li r24,1
537 b 1f
538 li r24,2
539 b 1f
540 li r24,3
5411:
14cf11af
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542
543_GLOBAL(pmac_secondary_start)
544 /* turn on 64-bit mode */
545 bl .enable_64b_mode
14cf11af 546
c478b581
BH
547 li r0,0
548 mfspr r3,SPRN_HID4
549 rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
550 sync
551 mtspr SPRN_HID4,r3
552 isync
553 sync
554 slbia
555
e31aa453
PM
556 /* get TOC pointer (real address) */
557 bl .relative_toc
1fbe9cf2 558 tovirt(r2,r2)
e31aa453 559
14cf11af 560 /* Copy some CPU settings from CPU 0 */
f39b7a55 561 bl .__restore_cpu_ppc970
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PM
562
563 /* pSeries do that early though I don't think we really need it */
564 mfmsr r3
565 ori r3,r3,MSR_RI
566 mtmsrd r3 /* RI on */
567
568 /* Set up a paca value for this processor. */
1426d5a3
ME
569 LOAD_REG_ADDR(r4,paca) /* Load paca pointer */
570 ld r4,0(r4) /* Get base vaddr of paca array */
e31aa453 571 mulli r13,r24,PACA_SIZE /* Calculate vaddr of right paca */
14cf11af 572 add r13,r13,r4 /* for this processor. */
2dd60d79 573 SET_PACA(r13) /* Save vaddr of paca in an SPRG*/
14cf11af 574
62cc67b9
BH
575 /* Mark interrupts soft and hard disabled (they might be enabled
576 * in the PACA when doing hotplug)
577 */
578 li r0,0
579 stb r0,PACASOFTIRQEN(r13)
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580 li r0,PACA_IRQ_HARD_DIS
581 stb r0,PACAIRQHAPPENED(r13)
62cc67b9 582
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583 /* Create a temp kernel stack for use before relocation is on. */
584 ld r1,PACAEMERGSP(r13)
585 subi r1,r1,STACK_FRAME_OVERHEAD
586
c705677e 587 b __secondary_start
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588
589#endif /* CONFIG_PPC_PMAC */
590
591/*
592 * This function is called after the master CPU has released the
593 * secondary processors. The execution environment is relocation off.
594 * The paca for this processor has the following fields initialized at
595 * this point:
596 * 1. Processor number
597 * 2. Segment table pointer (virtual address)
598 * On entry the following are set:
4f8cf36f 599 * r1 = stack pointer (real addr of temp stack)
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600 * r24 = cpu# (in Linux terms)
601 * r13 = paca virtual address
602 * SPRG_PACA = paca virtual address
14cf11af 603 */
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604 .section ".text";
605 .align 2 ;
606
fc68e869 607 .globl __secondary_start
c705677e 608__secondary_start:
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609 /* Set thread priority to MEDIUM */
610 HMT_MEDIUM
14cf11af 611
4f8cf36f 612 /* Initialize the kernel stack */
e58c3495 613 LOAD_REG_ADDR(r3, current_set)
14cf11af 614 sldi r28,r24,3 /* get current_set[cpu#] */
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615 ldx r14,r3,r28
616 addi r14,r14,THREAD_SIZE-STACK_FRAME_OVERHEAD
617 std r14,PACAKSAVE(r13)
14cf11af 618
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619 /* Do early setup for that CPU (stab, slb, hash table pointer) */
620 bl .early_setup_secondary
621
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622 /*
623 * setup the new stack pointer, but *don't* use this until
624 * translation is on.
625 */
626 mr r1, r14
627
799d6046 628 /* Clear backchain so we get nice backtraces */
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629 li r7,0
630 mtlr r7
631
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632 /* Mark interrupts soft and hard disabled (they might be enabled
633 * in the PACA when doing hotplug)
634 */
4f8cf36f 635 stb r7,PACASOFTIRQEN(r13)
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636 li r0,PACA_IRQ_HARD_DIS
637 stb r0,PACAIRQHAPPENED(r13)
4f8cf36f 638
14cf11af 639 /* enable MMU and jump to start_secondary */
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640 LOAD_REG_ADDR(r3, .start_secondary_prolog)
641 LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
d04c56f7 642
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643 mtspr SPRN_SRR0,r3
644 mtspr SPRN_SRR1,r4
2d27cfd3 645 RFI
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646 b . /* prevent speculative execution */
647
648/*
649 * Running with relocation on at this point. All we want to do is
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650 * zero the stack back-chain pointer and get the TOC virtual address
651 * before going into C code.
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652 */
653_GLOBAL(start_secondary_prolog)
e31aa453 654 ld r2,PACATOC(r13)
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655 li r3,0
656 std r3,0(r1) /* Zero the stack frame pointer */
657 bl .start_secondary
799d6046 658 b .
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659/*
660 * Reset stack pointer and call start_secondary
661 * to continue with online operation when woken up
662 * from cede in cpu offline.
663 */
664_GLOBAL(start_secondary_resume)
665 ld r1,PACAKSAVE(r13) /* Reload kernel stack pointer */
666 li r3,0
667 std r3,0(r1) /* Zero the stack frame pointer */
668 bl .start_secondary
669 b .
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670#endif
671
672/*
673 * This subroutine clobbers r11 and r12
674 */
675_GLOBAL(enable_64b_mode)
676 mfmsr r11 /* grab the current MSR */
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BH
677#ifdef CONFIG_PPC_BOOK3E
678 oris r11,r11,0x8000 /* CM bit set, we'll set ICM later */
679 mtmsr r11
680#else /* CONFIG_PPC_BOOK3E */
9f0b0793 681 li r12,(MSR_64BIT | MSR_ISF)@highest
e31aa453 682 sldi r12,r12,48
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683 or r11,r11,r12
684 mtmsrd r11
685 isync
2d27cfd3 686#endif
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687 blr
688
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689/*
690 * This puts the TOC pointer into r2, offset by 0x8000 (as expected
691 * by the toolchain). It computes the correct value for wherever we
692 * are running at the moment, using position-independent code.
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693 *
694 * Note: The compiler constructs pointers using offsets from the
695 * TOC in -mcmodel=medium mode. After we relocate to 0 but before
696 * the MMU is on we need our TOC to be a virtual address otherwise
697 * these pointers will be real addresses which may get stored and
698 * accessed later with the MMU on. We use tovirt() at the call
699 * sites to handle this.
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700 */
701_GLOBAL(relative_toc)
702 mflr r0
703 bcl 20,31,$+4
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7040: mflr r11
705 ld r2,(p_toc - 0b)(r11)
706 add r2,r2,r11
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707 mtlr r0
708 blr
709
5b63fee1 710.balign 8
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711p_toc: .llong __toc_start + 0x8000 - 0b
712
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713/*
714 * This is where the main kernel code starts.
715 */
939e60f6 716_INIT_STATIC(start_here_multiplatform)
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717 /* set up the TOC */
718 bl .relative_toc
719 tovirt(r2,r2)
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720
721 /* Clear out the BSS. It may have been done in prom_init,
722 * already but that's irrelevant since prom_init will soon
723 * be detached from the kernel completely. Besides, we need
724 * to clear it now for kexec-style entry.
725 */
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726 LOAD_REG_ADDR(r11,__bss_stop)
727 LOAD_REG_ADDR(r8,__bss_start)
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728 sub r11,r11,r8 /* bss size */
729 addi r11,r11,7 /* round up to an even double word */
e31aa453 730 srdi. r11,r11,3 /* shift right by 3 */
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731 beq 4f
732 addi r8,r8,-8
733 li r0,0
734 mtctr r11 /* zero this many doublewords */
7353: stdu r0,8(r8)
736 bdnz 3b
7374:
738
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739#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
740 /* Setup OPAL entry */
ab7f961a 741 LOAD_REG_ADDR(r11, opal)
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742 std r28,0(r11);
743 std r29,8(r11);
744#endif
745
2d27cfd3 746#ifndef CONFIG_PPC_BOOK3E
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747 mfmsr r6
748 ori r6,r6,MSR_RI
749 mtmsrd r6 /* RI on */
2d27cfd3 750#endif
14cf11af 751
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752#ifdef CONFIG_RELOCATABLE
753 /* Save the physical address we're running at in kernstart_addr */
754 LOAD_REG_ADDR(r4, kernstart_addr)
755 clrldi r0,r25,2
756 std r0,0(r4)
757#endif
758
e31aa453 759 /* The following gets the stack set up with the regs */
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760 /* pointing to the real addr of the kernel stack. This is */
761 /* all done to support the C function call below which sets */
762 /* up the htab. This is done because we have relocated the */
763 /* kernel but are still running in real mode. */
764
e31aa453 765 LOAD_REG_ADDR(r3,init_thread_union)
14cf11af 766
e31aa453 767 /* set up a stack pointer */
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768 addi r1,r3,THREAD_SIZE
769 li r0,0
770 stdu r0,-STACK_FRAME_OVERHEAD(r1)
771
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772 /* Do very early kernel initializations, including initial hash table,
773 * stab and slb setup before we turn on relocation. */
774
775 /* Restore parameters passed from prom_init/kexec */
776 mr r3,r31
ee43eb78 777 bl .early_setup /* also sets r13 and SPRG_PACA */
14cf11af 778
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779 LOAD_REG_ADDR(r3, .start_here_common)
780 ld r4,PACAKMSR(r13)
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781 mtspr SPRN_SRR0,r3
782 mtspr SPRN_SRR1,r4
2d27cfd3 783 RFI
14cf11af 784 b . /* prevent speculative execution */
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785
786 /* This is where all platforms converge execution */
fc68e869 787_INIT_GLOBAL(start_here_common)
14cf11af 788 /* relocation is on at this point */
e31aa453 789 std r1,PACAKSAVE(r13)
14cf11af 790
e31aa453 791 /* Load the TOC (virtual address) */
14cf11af 792 ld r2,PACATOC(r13)
14cf11af 793
7230c564 794 /* Do more system initializations in virtual mode */
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795 bl .setup_system
796
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797 /* Mark interrupts soft and hard disabled (they might be enabled
798 * in the PACA when doing hotplug)
799 */
800 li r0,0
801 stb r0,PACASOFTIRQEN(r13)
802 li r0,PACA_IRQ_HARD_DIS
803 stb r0,PACAIRQHAPPENED(r13)
14cf11af 804
7230c564 805 /* Generic kernel entry */
ff3da2e0 806 bl .start_kernel
14cf11af 807
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808 /* Not reached */
809 BUG_OPCODE
14cf11af 810
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811/*
812 * We put a few things here that have to be page-aligned.
813 * This stuff goes at the beginning of the bss, which is page-aligned.
814 */
815 .section ".bss"
816
817 .align PAGE_SHIFT
818
819 .globl empty_zero_page
820empty_zero_page:
821 .space PAGE_SIZE
822
823 .globl swapper_pg_dir
824swapper_pg_dir:
ee7a76da 825 .space PGD_TABLE_SIZE