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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * PowerPC version
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 *
6 * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
7 * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
8 * Adapted for Power Macintosh by Paul Mackerras.
9 * Low-level exception handlers and MMU support
10 * rewritten by Paul Mackerras.
11 * Copyright (C) 1996 Paul Mackerras.
12 *
13 * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
14 * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
15 *
16 * This file contains the entry point for the 64-bit kernel along
17 * with some early initialization code common to all 64-bit powerpc
18 * variants.
19 */
20
21#include <linux/linkage.h>
22#include <linux/threads.h>
23#include <linux/init.h>
24#include <asm/reg.h>
25#include <asm/page.h>
26#include <asm/mmu.h>
27#include <asm/ppc_asm.h>
28#include <asm/head-64.h>
29#include <asm/asm-offsets.h>
30#include <asm/bug.h>
31#include <asm/cputable.h>
32#include <asm/setup.h>
33#include <asm/hvcall.h>
34#include <asm/thread_info.h>
35#include <asm/firmware.h>
36#include <asm/page_64.h>
37#include <asm/irqflags.h>
38#include <asm/kvm_book3s_asm.h>
39#include <asm/ptrace.h>
40#include <asm/hw_irq.h>
41#include <asm/cputhreads.h>
42#include <asm/ppc-opcode.h>
43#include <asm/export.h>
44#include <asm/feature-fixups.h>
45#ifdef CONFIG_PPC_BOOK3S
46#include <asm/exception-64s.h>
47#else
48#include <asm/exception-64e.h>
49#endif
50
51/* The physical memory is laid out such that the secondary processor
52 * spin code sits at 0x0000...0x00ff. On server, the vectors follow
53 * using the layout described in exceptions-64s.S
54 */
55
56/*
57 * Entering into this code we make the following assumptions:
58 *
59 * For pSeries or server processors:
60 * 1. The MMU is off & open firmware is running in real mode.
61 * 2. The primary CPU enters at __start.
62 * 3. If the RTAS supports "query-cpu-stopped-state", then secondary
63 * CPUs will enter as directed by "start-cpu" RTAS call, which is
64 * generic_secondary_smp_init, with PIR in r3.
65 * 4. Else the secondary CPUs will enter at secondary_hold (0x60) as
66 * directed by the "start-cpu" RTS call, with PIR in r3.
67 * -or- For OPAL entry:
68 * 1. The MMU is off, processor in HV mode.
69 * 2. The primary CPU enters at 0 with device-tree in r3, OPAL base
70 * in r8, and entry in r9 for debugging purposes.
71 * 3. Secondary CPUs enter as directed by OPAL_START_CPU call, which
72 * is at generic_secondary_smp_init, with PIR in r3.
73 *
74 * For Book3E processors:
75 * 1. The MMU is on running in AS0 in a state defined in ePAPR
76 * 2. The kernel is entered at __start
77 */
78
79OPEN_FIXED_SECTION(first_256B, 0x0, 0x100)
80USE_FIXED_SECTION(first_256B)
81 /*
82 * Offsets are relative from the start of fixed section, and
83 * first_256B starts at 0. Offsets are a bit easier to use here
84 * than the fixed section entry macros.
85 */
86 . = 0x0
87_GLOBAL(__start)
88 /* NOP this out unconditionally */
89BEGIN_FTR_SECTION
90 FIXUP_ENDIAN
91 b __start_initialization_multiplatform
92END_FTR_SECTION(0, 1)
93
94 /* Catch branch to 0 in real mode */
95 trap
96
97 /* Secondary processors spin on this value until it becomes non-zero.
98 * When non-zero, it contains the real address of the function the cpu
99 * should jump to.
100 */
101 .balign 8
102 .globl __secondary_hold_spinloop
103__secondary_hold_spinloop:
104 .8byte 0x0
105
106 /* Secondary processors write this value with their cpu # */
107 /* after they enter the spin loop immediately below. */
108 .globl __secondary_hold_acknowledge
109__secondary_hold_acknowledge:
110 .8byte 0x0
111
112#ifdef CONFIG_RELOCATABLE
113 /* This flag is set to 1 by a loader if the kernel should run
114 * at the loaded address instead of the linked address. This
115 * is used by kexec-tools to keep the kdump kernel in the
116 * crash_kernel region. The loader is responsible for
117 * observing the alignment requirement.
118 */
119
120#ifdef CONFIG_RELOCATABLE_TEST
121#define RUN_AT_LOAD_DEFAULT 1 /* Test relocation, do not copy to 0 */
122#else
123#define RUN_AT_LOAD_DEFAULT 0x72756e30 /* "run0" -- relocate to 0 by default */
124#endif
125
126 /* Do not move this variable as kexec-tools knows about it. */
127 . = 0x5c
128 .globl __run_at_load
129__run_at_load:
130DEFINE_FIXED_SYMBOL(__run_at_load, first_256B)
131 .long RUN_AT_LOAD_DEFAULT
132#endif
133
134 . = 0x60
135/*
136 * The following code is used to hold secondary processors
137 * in a spin loop after they have entered the kernel, but
138 * before the bulk of the kernel has been relocated. This code
139 * is relocated to physical address 0x60 before prom_init is run.
140 * All of it must fit below the first exception vector at 0x100.
141 * Use .globl here not _GLOBAL because we want __secondary_hold
142 * to be the actual text address, not a descriptor.
143 */
144 .globl __secondary_hold
145__secondary_hold:
146 FIXUP_ENDIAN
147#ifndef CONFIG_PPC_BOOK3E_64
148 mfmsr r24
149 ori r24,r24,MSR_RI
150 mtmsrd r24 /* RI on */
151#endif
152 /* Grab our physical cpu number */
153 mr r24,r3
154 /* stash r4 for book3e */
155 mr r25,r4
156
157 /* Tell the master cpu we're here */
158 /* Relocation is off & we are located at an address less */
159 /* than 0x100, so only need to grab low order offset. */
160 std r24,(ABS_ADDR(__secondary_hold_acknowledge, first_256B))(0)
161 sync
162
163 li r26,0
164#ifdef CONFIG_PPC_BOOK3E_64
165 tovirt(r26,r26)
166#endif
167 /* All secondary cpus wait here until told to start. */
168100: ld r12,(ABS_ADDR(__secondary_hold_spinloop, first_256B))(r26)
169 cmpdi 0,r12,0
170 beq 100b
171
172#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC_CORE)
173#ifdef CONFIG_PPC_BOOK3E_64
174 tovirt(r12,r12)
175#endif
176 mtctr r12
177 mr r3,r24
178 /*
179 * it may be the case that other platforms have r4 right to
180 * begin with, this gives us some safety in case it is not
181 */
182#ifdef CONFIG_PPC_BOOK3E_64
183 mr r4,r25
184#else
185 li r4,0
186#endif
187 /* Make sure that patched code is visible */
188 isync
189 bctr
190#else
1910: trap
192 EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
193#endif
194CLOSE_FIXED_SECTION(first_256B)
195
196/*
197 * On server, we include the exception vectors code here as it
198 * relies on absolute addressing which is only possible within
199 * this compilation unit
200 */
201#ifdef CONFIG_PPC_BOOK3S
202#include "exceptions-64s.S"
203#else
204OPEN_TEXT_SECTION(0x100)
205#endif
206
207USE_TEXT_SECTION()
208
209#include "interrupt_64.S"
210
211#ifdef CONFIG_PPC_BOOK3E_64
212/*
213 * The booting_thread_hwid holds the thread id we want to boot in cpu
214 * hotplug case. It is set by cpu hotplug code, and is invalid by default.
215 * The thread id is the same as the initial value of SPRN_PIR[THREAD_ID]
216 * bit field.
217 */
218 .globl booting_thread_hwid
219booting_thread_hwid:
220 .long INVALID_THREAD_HWID
221 .align 3
222/*
223 * start a thread in the same core
224 * input parameters:
225 * r3 = the thread physical id
226 * r4 = the entry point where thread starts
227 */
228_GLOBAL(book3e_start_thread)
229 LOAD_REG_IMMEDIATE(r5, MSR_KERNEL)
230 cmpwi r3, 0
231 beq 10f
232 cmpwi r3, 1
233 beq 11f
234 /* If the thread id is invalid, just exit. */
235 b 13f
23610:
237 MTTMR(TMRN_IMSR0, 5)
238 MTTMR(TMRN_INIA0, 4)
239 b 12f
24011:
241 MTTMR(TMRN_IMSR1, 5)
242 MTTMR(TMRN_INIA1, 4)
24312:
244 isync
245 li r6, 1
246 sld r6, r6, r3
247 mtspr SPRN_TENS, r6
24813:
249 blr
250
251/*
252 * stop a thread in the same core
253 * input parameter:
254 * r3 = the thread physical id
255 */
256_GLOBAL(book3e_stop_thread)
257 cmpwi r3, 0
258 beq 10f
259 cmpwi r3, 1
260 beq 10f
261 /* If the thread id is invalid, just exit. */
262 b 13f
26310:
264 li r4, 1
265 sld r4, r4, r3
266 mtspr SPRN_TENC, r4
26713:
268 blr
269
270_GLOBAL(fsl_secondary_thread_init)
271 mfspr r4,SPRN_BUCSR
272
273 /* Enable branch prediction */
274 lis r3,BUCSR_INIT@h
275 ori r3,r3,BUCSR_INIT@l
276 mtspr SPRN_BUCSR,r3
277 isync
278
279 /*
280 * Fix PIR to match the linear numbering in the device tree.
281 *
282 * On e6500, the reset value of PIR uses the low three bits for
283 * the thread within a core, and the upper bits for the core
284 * number. There are two threads per core, so shift everything
285 * but the low bit right by two bits so that the cpu numbering is
286 * continuous.
287 *
288 * If the old value of BUCSR is non-zero, this thread has run
289 * before. Thus, we assume we are coming from kexec or a similar
290 * scenario, and PIR is already set to the correct value. This
291 * is a bit of a hack, but there are limited opportunities for
292 * getting information into the thread and the alternatives
293 * seemed like they'd be overkill. We can't tell just by looking
294 * at the old PIR value which state it's in, since the same value
295 * could be valid for one thread out of reset and for a different
296 * thread in Linux.
297 */
298
299 mfspr r3, SPRN_PIR
300 cmpwi r4,0
301 bne 1f
302 rlwimi r3, r3, 30, 2, 30
303 mtspr SPRN_PIR, r3
3041:
305 mr r24,r3
306
307 /* turn on 64-bit mode */
308 bl enable_64b_mode
309
310 /* get a valid TOC pointer, wherever we're mapped at */
311 bl relative_toc
312 tovirt(r2,r2)
313
314 /* Book3E initialization */
315 mr r3,r24
316 bl book3e_secondary_thread_init
317 b generic_secondary_common_init
318
319#endif /* CONFIG_PPC_BOOK3E_64 */
320
321/*
322 * On pSeries and most other platforms, secondary processors spin
323 * in the following code.
324 * At entry, r3 = this processor's number (physical cpu id)
325 *
326 * On Book3E, r4 = 1 to indicate that the initial TLB entry for
327 * this core already exists (setup via some other mechanism such
328 * as SCOM before entry).
329 */
330_GLOBAL(generic_secondary_smp_init)
331 FIXUP_ENDIAN
332 mr r24,r3
333 mr r25,r4
334
335 /* turn on 64-bit mode */
336 bl enable_64b_mode
337
338 /* get a valid TOC pointer, wherever we're mapped at */
339 bl relative_toc
340 tovirt(r2,r2)
341
342#ifdef CONFIG_PPC_BOOK3E_64
343 /* Book3E initialization */
344 mr r3,r24
345 mr r4,r25
346 bl book3e_secondary_core_init
347
348/*
349 * After common core init has finished, check if the current thread is the
350 * one we wanted to boot. If not, start the specified thread and stop the
351 * current thread.
352 */
353 LOAD_REG_ADDR(r4, booting_thread_hwid)
354 lwz r3, 0(r4)
355 li r5, INVALID_THREAD_HWID
356 cmpw r3, r5
357 beq 20f
358
359 /*
360 * The value of booting_thread_hwid has been stored in r3,
361 * so make it invalid.
362 */
363 stw r5, 0(r4)
364
365 /*
366 * Get the current thread id and check if it is the one we wanted.
367 * If not, start the one specified in booting_thread_hwid and stop
368 * the current thread.
369 */
370 mfspr r8, SPRN_TIR
371 cmpw r3, r8
372 beq 20f
373
374 /* start the specified thread */
375 LOAD_REG_ADDR(r5, fsl_secondary_thread_init)
376 ld r4, 0(r5)
377 bl book3e_start_thread
378
379 /* stop the current thread */
380 mr r3, r8
381 bl book3e_stop_thread
38210:
383 b 10b
38420:
385#endif
386
387generic_secondary_common_init:
388 /* Set up a paca value for this processor. Since we have the
389 * physical cpu id in r24, we need to search the pacas to find
390 * which logical id maps to our physical one.
391 */
392#ifndef CONFIG_SMP
393 b kexec_wait /* wait for next kernel if !SMP */
394#else
395 LOAD_REG_ADDR(r8, paca_ptrs) /* Load paca_ptrs pointe */
396 ld r8,0(r8) /* Get base vaddr of array */
397#if (NR_CPUS == 1) || defined(CONFIG_FORCE_NR_CPUS)
398 LOAD_REG_IMMEDIATE(r7, NR_CPUS)
399#else
400 LOAD_REG_ADDR(r7, nr_cpu_ids) /* Load nr_cpu_ids address */
401 lwz r7,0(r7) /* also the max paca allocated */
402#endif
403 li r5,0 /* logical cpu id */
4041:
405 sldi r9,r5,3 /* get paca_ptrs[] index from cpu id */
406 ldx r13,r9,r8 /* r13 = paca_ptrs[cpu id] */
407 lhz r6,PACAHWCPUID(r13) /* Load HW procid from paca */
408 cmpw r6,r24 /* Compare to our id */
409 beq 2f
410 addi r5,r5,1
411 cmpw r5,r7 /* Check if more pacas exist */
412 blt 1b
413
414 mr r3,r24 /* not found, copy phys to r3 */
415 b kexec_wait /* next kernel might do better */
416
4172: SET_PACA(r13)
418#ifdef CONFIG_PPC_BOOK3E_64
419 addi r12,r13,PACA_EXTLB /* and TLB exc frame in another */
420 mtspr SPRN_SPRG_TLB_EXFRAME,r12
421#endif
422
423 /* From now on, r24 is expected to be logical cpuid */
424 mr r24,r5
425
426 /* Create a temp kernel stack for use before relocation is on. */
427 ld r1,PACAEMERGSP(r13)
428 subi r1,r1,STACK_FRAME_MIN_SIZE
429
430 /* See if we need to call a cpu state restore handler */
431 LOAD_REG_ADDR(r23, cur_cpu_spec)
432 ld r23,0(r23)
433 ld r12,CPU_SPEC_RESTORE(r23)
434 cmpdi 0,r12,0
435 beq 3f
436#ifdef CONFIG_PPC64_ELF_ABI_V1
437 ld r12,0(r12)
438#endif
439 mtctr r12
440 bctrl
441
4423: LOAD_REG_ADDR(r3, spinning_secondaries) /* Decrement spinning_secondaries */
443 lwarx r4,0,r3
444 subi r4,r4,1
445 stwcx. r4,0,r3
446 bne 3b
447 isync
448
4494: HMT_LOW
450 lbz r23,PACAPROCSTART(r13) /* Test if this processor should */
451 /* start. */
452 cmpwi 0,r23,0
453 beq 4b /* Loop until told to go */
454
455 sync /* order paca.run and cur_cpu_spec */
456 isync /* In case code patching happened */
457
458 b __secondary_start
459#endif /* SMP */
460
461/*
462 * Turn the MMU off.
463 * Assumes we're mapped EA == RA if the MMU is on.
464 */
465#ifdef CONFIG_PPC_BOOK3S
466SYM_FUNC_START_LOCAL(__mmu_off)
467 mfmsr r3
468 andi. r0,r3,MSR_IR|MSR_DR
469 beqlr
470 mflr r4
471 andc r3,r3,r0
472 mtspr SPRN_SRR0,r4
473 mtspr SPRN_SRR1,r3
474 sync
475 rfid
476 b . /* prevent speculative execution */
477SYM_FUNC_END(__mmu_off)
478#endif
479
480
481/*
482 * Here is our main kernel entry point. We support currently 2 kind of entries
483 * depending on the value of r5.
484 *
485 * r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content
486 * in r3...r7
487 *
488 * r5 == NULL -> kexec style entry. r3 is a physical pointer to the
489 * DT block, r4 is a physical pointer to the kernel itself
490 *
491 */
492__start_initialization_multiplatform:
493 /* Make sure we are running in 64 bits mode */
494 bl enable_64b_mode
495
496 /* Zero r13 (paca) so early program check / mce don't use it */
497 li r13,0
498
499 /* Get TOC pointer (current runtime address) */
500 bl relative_toc
501
502 /* find out where we are now */
503 bcl 20,31,$+4
5040: mflr r26 /* r26 = runtime addr here */
505 addis r26,r26,(_stext - 0b)@ha
506 addi r26,r26,(_stext - 0b)@l /* current runtime base addr */
507
508 /*
509 * Are we booted from a PROM Of-type client-interface ?
510 */
511 cmpldi cr0,r5,0
512 beq 1f
513 b __boot_from_prom /* yes -> prom */
5141:
515 /* Save parameters */
516 mr r31,r3
517 mr r30,r4
518#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
519 /* Save OPAL entry */
520 mr r28,r8
521 mr r29,r9
522#endif
523
524#ifdef CONFIG_PPC_BOOK3E_64
525 bl start_initialization_book3e
526 b __after_prom_start
527#else
528 /* Setup some critical 970 SPRs before switching MMU off */
529 mfspr r0,SPRN_PVR
530 srwi r0,r0,16
531 cmpwi r0,0x39 /* 970 */
532 beq 1f
533 cmpwi r0,0x3c /* 970FX */
534 beq 1f
535 cmpwi r0,0x44 /* 970MP */
536 beq 1f
537 cmpwi r0,0x45 /* 970GX */
538 bne 2f
5391: bl __cpu_preinit_ppc970
5402:
541
542 /* Switch off MMU if not already off */
543 bl __mmu_off
544 b __after_prom_start
545#endif /* CONFIG_PPC_BOOK3E_64 */
546
547__REF
548__boot_from_prom:
549#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
550 /* Save parameters */
551 mr r31,r3
552 mr r30,r4
553 mr r29,r5
554 mr r28,r6
555 mr r27,r7
556
557 /*
558 * Align the stack to 16-byte boundary
559 * Depending on the size and layout of the ELF sections in the initial
560 * boot binary, the stack pointer may be unaligned on PowerMac
561 */
562 rldicr r1,r1,0,59
563
564#ifdef CONFIG_RELOCATABLE
565 /* Relocate code for where we are now */
566 mr r3,r26
567 bl relocate
568#endif
569
570 /* Restore parameters */
571 mr r3,r31
572 mr r4,r30
573 mr r5,r29
574 mr r6,r28
575 mr r7,r27
576
577 /* Do all of the interaction with OF client interface */
578 mr r8,r26
579 bl prom_init
580#endif /* #CONFIG_PPC_OF_BOOT_TRAMPOLINE */
581
582 /* We never return. We also hit that trap if trying to boot
583 * from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */
584 trap
585 .previous
586
587__after_prom_start:
588#ifdef CONFIG_RELOCATABLE
589 /* process relocations for the final address of the kernel */
590 lis r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
591 sldi r25,r25,32
592#if defined(CONFIG_PPC_BOOK3E_64)
593 tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */
594#endif
595 lwz r7,(FIXED_SYMBOL_ABS_ADDR(__run_at_load))(r26)
596#if defined(CONFIG_PPC_BOOK3E_64)
597 tophys(r26,r26)
598#endif
599 cmplwi cr0,r7,1 /* flagged to stay where we are ? */
600 bne 1f
601 add r25,r25,r26
6021: mr r3,r25
603 bl relocate
604#if defined(CONFIG_PPC_BOOK3E_64)
605 /* IVPR needs to be set after relocation. */
606 bl init_core_book3e
607#endif
608#endif
609
610/*
611 * We need to run with _stext at physical address PHYSICAL_START.
612 * This will leave some code in the first 256B of
613 * real memory, which are reserved for software use.
614 *
615 * Note: This process overwrites the OF exception vectors.
616 */
617 li r3,0 /* target addr */
618#ifdef CONFIG_PPC_BOOK3E_64
619 tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */
620#endif
621 mr. r4,r26 /* In some cases the loader may */
622#if defined(CONFIG_PPC_BOOK3E_64)
623 tovirt(r4,r4)
624#endif
625 beq 9f /* have already put us at zero */
626 li r6,0x100 /* Start offset, the first 0x100 */
627 /* bytes were copied earlier. */
628
629#ifdef CONFIG_RELOCATABLE
630/*
631 * Check if the kernel has to be running as relocatable kernel based on the
632 * variable __run_at_load, if it is set the kernel is treated as relocatable
633 * kernel, otherwise it will be moved to PHYSICAL_START
634 */
635#if defined(CONFIG_PPC_BOOK3E_64)
636 tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */
637#endif
638 lwz r7,(FIXED_SYMBOL_ABS_ADDR(__run_at_load))(r26)
639 cmplwi cr0,r7,1
640 bne 3f
641
642#ifdef CONFIG_PPC_BOOK3E_64
643 LOAD_REG_ADDR(r5, __end_interrupts)
644 LOAD_REG_ADDR(r11, _stext)
645 sub r5,r5,r11
646#else
647 /* just copy interrupts */
648 LOAD_REG_IMMEDIATE_SYM(r5, r11, FIXED_SYMBOL_ABS_ADDR(__end_interrupts))
649#endif
650 b 5f
6513:
652#endif
653 /* # bytes of memory to copy */
654 lis r5,(ABS_ADDR(copy_to_here, text))@ha
655 addi r5,r5,(ABS_ADDR(copy_to_here, text))@l
656
657 bl copy_and_flush /* copy the first n bytes */
658 /* this includes the code being */
659 /* executed here. */
660 /* Jump to the copy of this code that we just made */
661 addis r8,r3,(ABS_ADDR(4f, text))@ha
662 addi r12,r8,(ABS_ADDR(4f, text))@l
663 mtctr r12
664 bctr
665
666.balign 8
667p_end: .8byte _end - copy_to_here
668
6694:
670 /*
671 * Now copy the rest of the kernel up to _end, add
672 * _end - copy_to_here to the copy limit and run again.
673 */
674 addis r8,r26,(ABS_ADDR(p_end, text))@ha
675 ld r8,(ABS_ADDR(p_end, text))@l(r8)
676 add r5,r5,r8
6775: bl copy_and_flush /* copy the rest */
678
6799: b start_here_multiplatform
680
681/*
682 * Copy routine used to copy the kernel to start at physical address 0
683 * and flush and invalidate the caches as needed.
684 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
685 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
686 *
687 * Note: this routine *only* clobbers r0, r6 and lr
688 */
689_GLOBAL(copy_and_flush)
690 addi r5,r5,-8
691 addi r6,r6,-8
6924: li r0,8 /* Use the smallest common */
693 /* denominator cache line */
694 /* size. This results in */
695 /* extra cache line flushes */
696 /* but operation is correct. */
697 /* Can't get cache line size */
698 /* from NACA as it is being */
699 /* moved too. */
700
701 mtctr r0 /* put # words/line in ctr */
7023: addi r6,r6,8 /* copy a cache line */
703 ldx r0,r6,r4
704 stdx r0,r6,r3
705 bdnz 3b
706 dcbst r6,r3 /* write it to memory */
707 sync
708 icbi r6,r3 /* flush the icache line */
709 cmpld 0,r6,r5
710 blt 4b
711 sync
712 addi r5,r5,8
713 addi r6,r6,8
714 isync
715 blr
716
717_ASM_NOKPROBE_SYMBOL(copy_and_flush); /* Called in real mode */
718
719.align 8
720copy_to_here:
721
722#ifdef CONFIG_SMP
723#ifdef CONFIG_PPC_PMAC
724/*
725 * On PowerMac, secondary processors starts from the reset vector, which
726 * is temporarily turned into a call to one of the functions below.
727 */
728 .section ".text";
729 .align 2 ;
730
731 .globl __secondary_start_pmac_0
732__secondary_start_pmac_0:
733 /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
734 li r24,0
735 b 1f
736 li r24,1
737 b 1f
738 li r24,2
739 b 1f
740 li r24,3
7411:
742
743_GLOBAL(pmac_secondary_start)
744 /* turn on 64-bit mode */
745 bl enable_64b_mode
746
747 li r0,0
748 mfspr r3,SPRN_HID4
749 rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
750 sync
751 mtspr SPRN_HID4,r3
752 isync
753 sync
754 slbia
755
756 /* get TOC pointer (real address) */
757 bl relative_toc
758 tovirt(r2,r2)
759
760 /* Copy some CPU settings from CPU 0 */
761 bl __restore_cpu_ppc970
762
763 /* pSeries do that early though I don't think we really need it */
764 mfmsr r3
765 ori r3,r3,MSR_RI
766 mtmsrd r3 /* RI on */
767
768 /* Set up a paca value for this processor. */
769 LOAD_REG_ADDR(r4,paca_ptrs) /* Load paca pointer */
770 ld r4,0(r4) /* Get base vaddr of paca_ptrs array */
771 sldi r5,r24,3 /* get paca_ptrs[] index from cpu id */
772 ldx r13,r5,r4 /* r13 = paca_ptrs[cpu id] */
773 SET_PACA(r13) /* Save vaddr of paca in an SPRG*/
774
775 /* Mark interrupts soft and hard disabled (they might be enabled
776 * in the PACA when doing hotplug)
777 */
778 li r0,IRQS_DISABLED
779 stb r0,PACAIRQSOFTMASK(r13)
780 li r0,PACA_IRQ_HARD_DIS
781 stb r0,PACAIRQHAPPENED(r13)
782
783 /* Create a temp kernel stack for use before relocation is on. */
784 ld r1,PACAEMERGSP(r13)
785 subi r1,r1,STACK_FRAME_MIN_SIZE
786
787 b __secondary_start
788
789#endif /* CONFIG_PPC_PMAC */
790
791/*
792 * This function is called after the master CPU has released the
793 * secondary processors. The execution environment is relocation off.
794 * The paca for this processor has the following fields initialized at
795 * this point:
796 * 1. Processor number
797 * 2. Segment table pointer (virtual address)
798 * On entry the following are set:
799 * r1 = stack pointer (real addr of temp stack)
800 * r24 = cpu# (in Linux terms)
801 * r13 = paca virtual address
802 * SPRG_PACA = paca virtual address
803 */
804 .section ".text";
805 .align 2 ;
806
807 .globl __secondary_start
808__secondary_start:
809 /* Set thread priority to MEDIUM */
810 HMT_MEDIUM
811
812 /*
813 * Do early setup for this CPU, in particular initialising the MMU so we
814 * can turn it on below. This is a call to C, which is OK, we're still
815 * running on the emergency stack.
816 */
817 bl early_setup_secondary
818
819 /*
820 * The primary has initialized our kernel stack for us in the paca, grab
821 * it and put it in r1. We must *not* use it until we turn on the MMU
822 * below, because it may not be inside the RMO.
823 */
824 ld r1, PACAKSAVE(r13)
825
826 /* Clear backchain so we get nice backtraces */
827 li r7,0
828 mtlr r7
829
830 /* Mark interrupts soft and hard disabled (they might be enabled
831 * in the PACA when doing hotplug)
832 */
833 li r7,IRQS_DISABLED
834 stb r7,PACAIRQSOFTMASK(r13)
835 li r0,PACA_IRQ_HARD_DIS
836 stb r0,PACAIRQHAPPENED(r13)
837
838 /* enable MMU and jump to start_secondary */
839 LOAD_REG_ADDR(r3, start_secondary_prolog)
840 LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
841
842 mtspr SPRN_SRR0,r3
843 mtspr SPRN_SRR1,r4
844 RFI_TO_KERNEL
845 b . /* prevent speculative execution */
846
847/*
848 * Running with relocation on at this point. All we want to do is
849 * zero the stack back-chain pointer and get the TOC virtual address
850 * before going into C code.
851 */
852start_secondary_prolog:
853 LOAD_PACA_TOC()
854 li r3,0
855 std r3,0(r1) /* Zero the stack frame pointer */
856 bl start_secondary
857 b .
858/*
859 * Reset stack pointer and call start_secondary
860 * to continue with online operation when woken up
861 * from cede in cpu offline.
862 */
863_GLOBAL(start_secondary_resume)
864 ld r1,PACAKSAVE(r13) /* Reload kernel stack pointer */
865 li r3,0
866 std r3,0(r1) /* Zero the stack frame pointer */
867 bl start_secondary
868 b .
869#endif
870
871/*
872 * This subroutine clobbers r11 and r12
873 */
874SYM_FUNC_START_LOCAL(enable_64b_mode)
875 mfmsr r11 /* grab the current MSR */
876#ifdef CONFIG_PPC_BOOK3E_64
877 oris r11,r11,0x8000 /* CM bit set, we'll set ICM later */
878 mtmsr r11
879#else /* CONFIG_PPC_BOOK3E_64 */
880 LOAD_REG_IMMEDIATE(r12, MSR_64BIT)
881 or r11,r11,r12
882 mtmsrd r11
883 isync
884#endif
885 blr
886SYM_FUNC_END(enable_64b_mode)
887
888/*
889 * This puts the TOC pointer into r2, offset by 0x8000 (as expected
890 * by the toolchain). It computes the correct value for wherever we
891 * are running at the moment, using position-independent code.
892 *
893 * Note: The compiler constructs pointers using offsets from the
894 * TOC in -mcmodel=medium mode. After we relocate to 0 but before
895 * the MMU is on we need our TOC to be a virtual address otherwise
896 * these pointers will be real addresses which may get stored and
897 * accessed later with the MMU on. We use tovirt() at the call
898 * sites to handle this.
899 */
900_GLOBAL(relative_toc)
901 mflr r0
902 bcl 20,31,$+4
9030: mflr r11
904 ld r2,(p_toc - 0b)(r11)
905 add r2,r2,r11
906 mtlr r0
907 blr
908
909.balign 8
910p_toc: .8byte .TOC. - 0b
911
912/*
913 * This is where the main kernel code starts.
914 */
915__REF
916start_here_multiplatform:
917 /* set up the TOC */
918 bl relative_toc
919 tovirt(r2,r2)
920
921 /* Clear out the BSS. It may have been done in prom_init,
922 * already but that's irrelevant since prom_init will soon
923 * be detached from the kernel completely. Besides, we need
924 * to clear it now for kexec-style entry.
925 */
926 LOAD_REG_ADDR(r11,__bss_stop)
927 LOAD_REG_ADDR(r8,__bss_start)
928 sub r11,r11,r8 /* bss size */
929 addi r11,r11,7 /* round up to an even double word */
930 srdi. r11,r11,3 /* shift right by 3 */
931 beq 4f
932 addi r8,r8,-8
933 li r0,0
934 mtctr r11 /* zero this many doublewords */
9353: stdu r0,8(r8)
936 bdnz 3b
9374:
938
939#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
940 /* Setup OPAL entry */
941 LOAD_REG_ADDR(r11, opal)
942 std r28,0(r11);
943 std r29,8(r11);
944#endif
945
946#ifndef CONFIG_PPC_BOOK3E_64
947 mfmsr r6
948 ori r6,r6,MSR_RI
949 mtmsrd r6 /* RI on */
950#endif
951
952#ifdef CONFIG_RELOCATABLE
953 /* Save the physical address we're running at in kernstart_addr */
954 LOAD_REG_ADDR(r4, kernstart_addr)
955 clrldi r0,r25,2
956 std r0,0(r4)
957#endif
958
959 /* set up a stack pointer */
960 LOAD_REG_ADDR(r3,init_thread_union)
961 LOAD_REG_IMMEDIATE(r1,THREAD_SIZE)
962 add r1,r3,r1
963 li r0,0
964 stdu r0,-STACK_FRAME_MIN_SIZE(r1)
965
966 /*
967 * Do very early kernel initializations, including initial hash table
968 * and SLB setup before we turn on relocation.
969 */
970
971#ifdef CONFIG_KASAN
972 bl kasan_early_init
973#endif
974 /* Restore parameters passed from prom_init/kexec */
975 mr r3,r31
976 LOAD_REG_ADDR(r12, DOTSYM(early_setup))
977 mtctr r12
978 bctrl /* also sets r13 and SPRG_PACA */
979
980 LOAD_REG_ADDR(r3, start_here_common)
981 ld r4,PACAKMSR(r13)
982 mtspr SPRN_SRR0,r3
983 mtspr SPRN_SRR1,r4
984 RFI_TO_KERNEL
985 b . /* prevent speculative execution */
986
987 /* This is where all platforms converge execution */
988
989start_here_common:
990 /* relocation is on at this point */
991 std r1,PACAKSAVE(r13)
992
993 /* Load the TOC (virtual address) */
994 LOAD_PACA_TOC()
995
996 /* Mark interrupts soft and hard disabled (they might be enabled
997 * in the PACA when doing hotplug)
998 */
999 li r0,IRQS_DISABLED
1000 stb r0,PACAIRQSOFTMASK(r13)
1001 li r0,PACA_IRQ_HARD_DIS
1002 stb r0,PACAIRQHAPPENED(r13)
1003
1004 /* Generic kernel entry */
1005 bl start_kernel
1006
1007 /* Not reached */
10080: trap
1009 EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
1010 .previous
1/*
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 *
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.
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
25#include <linux/threads.h>
26#include <asm/reg.h>
27#include <asm/page.h>
28#include <asm/mmu.h>
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>
35#include <asm/thread_info.h>
36#include <asm/firmware.h>
37#include <asm/page_64.h>
38#include <asm/irqflags.h>
39#include <asm/kvm_book3s_asm.h>
40#include <asm/ptrace.h>
41#include <asm/hw_irq.h>
42
43/* The physical memory is laid out such that the secondary processor
44 * spin code sits at 0x0000...0x00ff. On server, the vectors follow
45 * using the layout described in exceptions-64s.S
46 */
47
48/*
49 * Entering into this code we make the following assumptions:
50 *
51 * For pSeries or server processors:
52 * 1. The MMU is off & open firmware is running in real mode.
53 * 2. The kernel is entered at __start
54 * -or- For OPAL entry:
55 * 1. The MMU is off, processor in HV mode, primary CPU enters at 0
56 * with device-tree in gpr3. We also get OPAL base in r8 and
57 * entry in r9 for debugging purposes
58 * 2. Secondary processors enter at 0x60 with PIR in gpr3
59 *
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
63 */
64
65 .text
66 .globl _stext
67_stext:
68_GLOBAL(__start)
69 /* NOP this out unconditionally */
70BEGIN_FTR_SECTION
71 b .__start_initialization_multiplatform
72END_FTR_SECTION(0, 1)
73
74 /* Catch branch to 0 in real mode */
75 trap
76
77 /* Secondary processors spin on this value until it becomes nonzero.
78 * When it does it contains the real address of the descriptor
79 * of the function that the cpu should jump to to continue
80 * initialization.
81 */
82 .globl __secondary_hold_spinloop
83__secondary_hold_spinloop:
84 .llong 0x0
85
86 /* Secondary processors write this value with their cpu # */
87 /* after they enter the spin loop immediately below. */
88 .globl __secondary_hold_acknowledge
89__secondary_hold_acknowledge:
90 .llong 0x0
91
92#ifdef CONFIG_RELOCATABLE
93 /* This flag is set to 1 by a loader if the kernel should run
94 * at the loaded address instead of the linked address. This
95 * is used by kexec-tools to keep the the kdump kernel in the
96 * crash_kernel region. The loader is responsible for
97 * observing the alignment requirement.
98 */
99 /* Do not move this variable as kexec-tools knows about it. */
100 . = 0x5c
101 .globl __run_at_load
102__run_at_load:
103 .long 0x72756e30 /* "run0" -- relocate to 0 by default */
104#endif
105
106 . = 0x60
107/*
108 * The following code is used to hold secondary processors
109 * in a spin loop after they have entered the kernel, but
110 * before the bulk of the kernel has been relocated. This code
111 * is relocated to physical address 0x60 before prom_init is run.
112 * All of it must fit below the first exception vector at 0x100.
113 * Use .globl here not _GLOBAL because we want __secondary_hold
114 * to be the actual text address, not a descriptor.
115 */
116 .globl __secondary_hold
117__secondary_hold:
118#ifndef CONFIG_PPC_BOOK3E
119 mfmsr r24
120 ori r24,r24,MSR_RI
121 mtmsrd r24 /* RI on */
122#endif
123 /* Grab our physical cpu number */
124 mr r24,r3
125
126 /* Tell the master cpu we're here */
127 /* Relocation is off & we are located at an address less */
128 /* than 0x100, so only need to grab low order offset. */
129 std r24,__secondary_hold_acknowledge-_stext(0)
130 sync
131
132 /* All secondary cpus wait here until told to start. */
133100: ld r4,__secondary_hold_spinloop-_stext(0)
134 cmpdi 0,r4,0
135 beq 100b
136
137#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
138 ld r4,0(r4) /* deref function descriptor */
139 mtctr r4
140 mr r3,r24
141 li r4,0
142 /* Make sure that patched code is visible */
143 isync
144 bctr
145#else
146 BUG_OPCODE
147#endif
148
149/* This value is used to mark exception frames on the stack. */
150 .section ".toc","aw"
151exception_marker:
152 .tc ID_72656773_68657265[TC],0x7265677368657265
153 .text
154
155/*
156 * On server, we include the exception vectors code here as it
157 * relies on absolute addressing which is only possible within
158 * this compilation unit
159 */
160#ifdef CONFIG_PPC_BOOK3S
161#include "exceptions-64s.S"
162#endif
163
164_GLOBAL(generic_secondary_thread_init)
165 mr r24,r3
166
167 /* turn on 64-bit mode */
168 bl .enable_64b_mode
169
170 /* get a valid TOC pointer, wherever we're mapped at */
171 bl .relative_toc
172
173#ifdef CONFIG_PPC_BOOK3E
174 /* Book3E initialization */
175 mr r3,r24
176 bl .book3e_secondary_thread_init
177#endif
178 b generic_secondary_common_init
179
180/*
181 * On pSeries and most other platforms, secondary processors spin
182 * in the following code.
183 * At entry, r3 = this processor's number (physical cpu id)
184 *
185 * On Book3E, r4 = 1 to indicate that the initial TLB entry for
186 * this core already exists (setup via some other mechanism such
187 * as SCOM before entry).
188 */
189_GLOBAL(generic_secondary_smp_init)
190 mr r24,r3
191 mr r25,r4
192
193 /* turn on 64-bit mode */
194 bl .enable_64b_mode
195
196 /* get a valid TOC pointer, wherever we're mapped at */
197 bl .relative_toc
198
199#ifdef CONFIG_PPC_BOOK3E
200 /* Book3E initialization */
201 mr r3,r24
202 mr r4,r25
203 bl .book3e_secondary_core_init
204#endif
205
206generic_secondary_common_init:
207 /* Set up a paca value for this processor. Since we have the
208 * physical cpu id in r24, we need to search the pacas to find
209 * which logical id maps to our physical one.
210 */
211 LOAD_REG_ADDR(r13, paca) /* Load paca pointer */
212 ld r13,0(r13) /* Get base vaddr of paca array */
213#ifndef CONFIG_SMP
214 addi r13,r13,PACA_SIZE /* know r13 if used accidentally */
215 b .kexec_wait /* wait for next kernel if !SMP */
216#else
217 LOAD_REG_ADDR(r7, nr_cpu_ids) /* Load nr_cpu_ids address */
218 lwz r7,0(r7) /* also the max paca allocated */
219 li r5,0 /* logical cpu id */
2201: lhz r6,PACAHWCPUID(r13) /* Load HW procid from paca */
221 cmpw r6,r24 /* Compare to our id */
222 beq 2f
223 addi r13,r13,PACA_SIZE /* Loop to next PACA on miss */
224 addi r5,r5,1
225 cmpw r5,r7 /* Check if more pacas exist */
226 blt 1b
227
228 mr r3,r24 /* not found, copy phys to r3 */
229 b .kexec_wait /* next kernel might do better */
230
2312: SET_PACA(r13)
232#ifdef CONFIG_PPC_BOOK3E
233 addi r12,r13,PACA_EXTLB /* and TLB exc frame in another */
234 mtspr SPRN_SPRG_TLB_EXFRAME,r12
235#endif
236
237 /* From now on, r24 is expected to be logical cpuid */
238 mr r24,r5
239
240 /* See if we need to call a cpu state restore handler */
241 LOAD_REG_ADDR(r23, cur_cpu_spec)
242 ld r23,0(r23)
243 ld r23,CPU_SPEC_RESTORE(r23)
244 cmpdi 0,r23,0
245 beq 3f
246 ld r23,0(r23)
247 mtctr r23
248 bctrl
249
2503: LOAD_REG_ADDR(r3, spinning_secondaries) /* Decrement spinning_secondaries */
251 lwarx r4,0,r3
252 subi r4,r4,1
253 stwcx. r4,0,r3
254 bne 3b
255 isync
256
2574: HMT_LOW
258 lbz r23,PACAPROCSTART(r13) /* Test if this processor should */
259 /* start. */
260 cmpwi 0,r23,0
261 beq 4b /* Loop until told to go */
262
263 sync /* order paca.run and cur_cpu_spec */
264 isync /* In case code patching happened */
265
266 /* Create a temp kernel stack for use before relocation is on. */
267 ld r1,PACAEMERGSP(r13)
268 subi r1,r1,STACK_FRAME_OVERHEAD
269
270 b __secondary_start
271#endif /* SMP */
272
273/*
274 * Turn the MMU off.
275 * Assumes we're mapped EA == RA if the MMU is on.
276 */
277#ifdef CONFIG_PPC_BOOK3S
278_STATIC(__mmu_off)
279 mfmsr r3
280 andi. r0,r3,MSR_IR|MSR_DR
281 beqlr
282 mflr r4
283 andc r3,r3,r0
284 mtspr SPRN_SRR0,r4
285 mtspr SPRN_SRR1,r3
286 sync
287 rfid
288 b . /* prevent speculative execution */
289#endif
290
291
292/*
293 * Here is our main kernel entry point. We support currently 2 kind of entries
294 * depending on the value of r5.
295 *
296 * r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content
297 * in r3...r7
298 *
299 * r5 == NULL -> kexec style entry. r3 is a physical pointer to the
300 * DT block, r4 is a physical pointer to the kernel itself
301 *
302 */
303_GLOBAL(__start_initialization_multiplatform)
304 /* Make sure we are running in 64 bits mode */
305 bl .enable_64b_mode
306
307 /* Get TOC pointer (current runtime address) */
308 bl .relative_toc
309
310 /* find out where we are now */
311 bcl 20,31,$+4
3120: mflr r26 /* r26 = runtime addr here */
313 addis r26,r26,(_stext - 0b)@ha
314 addi r26,r26,(_stext - 0b)@l /* current runtime base addr */
315
316 /*
317 * Are we booted from a PROM Of-type client-interface ?
318 */
319 cmpldi cr0,r5,0
320 beq 1f
321 b .__boot_from_prom /* yes -> prom */
3221:
323 /* Save parameters */
324 mr r31,r3
325 mr r30,r4
326#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
327 /* Save OPAL entry */
328 mr r28,r8
329 mr r29,r9
330#endif
331
332#ifdef CONFIG_PPC_BOOK3E
333 bl .start_initialization_book3e
334 b .__after_prom_start
335#else
336 /* Setup some critical 970 SPRs before switching MMU off */
337 mfspr r0,SPRN_PVR
338 srwi r0,r0,16
339 cmpwi r0,0x39 /* 970 */
340 beq 1f
341 cmpwi r0,0x3c /* 970FX */
342 beq 1f
343 cmpwi r0,0x44 /* 970MP */
344 beq 1f
345 cmpwi r0,0x45 /* 970GX */
346 bne 2f
3471: bl .__cpu_preinit_ppc970
3482:
349
350 /* Switch off MMU if not already off */
351 bl .__mmu_off
352 b .__after_prom_start
353#endif /* CONFIG_PPC_BOOK3E */
354
355_INIT_STATIC(__boot_from_prom)
356#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
357 /* Save parameters */
358 mr r31,r3
359 mr r30,r4
360 mr r29,r5
361 mr r28,r6
362 mr r27,r7
363
364 /*
365 * Align the stack to 16-byte boundary
366 * Depending on the size and layout of the ELF sections in the initial
367 * boot binary, the stack pointer may be unaligned on PowerMac
368 */
369 rldicr r1,r1,0,59
370
371#ifdef CONFIG_RELOCATABLE
372 /* Relocate code for where we are now */
373 mr r3,r26
374 bl .relocate
375#endif
376
377 /* Restore parameters */
378 mr r3,r31
379 mr r4,r30
380 mr r5,r29
381 mr r6,r28
382 mr r7,r27
383
384 /* Do all of the interaction with OF client interface */
385 mr r8,r26
386 bl .prom_init
387#endif /* #CONFIG_PPC_OF_BOOT_TRAMPOLINE */
388
389 /* We never return. We also hit that trap if trying to boot
390 * from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */
391 trap
392
393_STATIC(__after_prom_start)
394#ifdef CONFIG_RELOCATABLE
395 /* process relocations for the final address of the kernel */
396 lis r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
397 sldi r25,r25,32
398 lwz r7,__run_at_load-_stext(r26)
399 cmplwi cr0,r7,1 /* flagged to stay where we are ? */
400 bne 1f
401 add r25,r25,r26
4021: mr r3,r25
403 bl .relocate
404#endif
405
406/*
407 * We need to run with _stext at physical address PHYSICAL_START.
408 * This will leave some code in the first 256B of
409 * real memory, which are reserved for software use.
410 *
411 * Note: This process overwrites the OF exception vectors.
412 */
413 li r3,0 /* target addr */
414#ifdef CONFIG_PPC_BOOK3E
415 tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */
416#endif
417 mr. r4,r26 /* In some cases the loader may */
418 beq 9f /* have already put us at zero */
419 li r6,0x100 /* Start offset, the first 0x100 */
420 /* bytes were copied earlier. */
421#ifdef CONFIG_PPC_BOOK3E
422 tovirt(r6,r6) /* on booke, we already run at PAGE_OFFSET */
423#endif
424
425#ifdef CONFIG_CRASH_DUMP
426/*
427 * Check if the kernel has to be running as relocatable kernel based on the
428 * variable __run_at_load, if it is set the kernel is treated as relocatable
429 * kernel, otherwise it will be moved to PHYSICAL_START
430 */
431 lwz r7,__run_at_load-_stext(r26)
432 cmplwi cr0,r7,1
433 bne 3f
434
435 li r5,__end_interrupts - _stext /* just copy interrupts */
436 b 5f
4373:
438#endif
439 lis r5,(copy_to_here - _stext)@ha
440 addi r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
441
442 bl .copy_and_flush /* copy the first n bytes */
443 /* this includes the code being */
444 /* executed here. */
445 addis r8,r3,(4f - _stext)@ha /* Jump to the copy of this code */
446 addi r8,r8,(4f - _stext)@l /* that we just made */
447 mtctr r8
448 bctr
449
450p_end: .llong _end - _stext
451
4524: /* Now copy the rest of the kernel up to _end */
453 addis r5,r26,(p_end - _stext)@ha
454 ld r5,(p_end - _stext)@l(r5) /* get _end */
4555: bl .copy_and_flush /* copy the rest */
456
4579: b .start_here_multiplatform
458
459/*
460 * Copy routine used to copy the kernel to start at physical address 0
461 * and flush and invalidate the caches as needed.
462 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
463 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
464 *
465 * Note: this routine *only* clobbers r0, r6 and lr
466 */
467_GLOBAL(copy_and_flush)
468 addi r5,r5,-8
469 addi r6,r6,-8
4704: li r0,8 /* Use the smallest common */
471 /* denominator cache line */
472 /* size. This results in */
473 /* extra cache line flushes */
474 /* but operation is correct. */
475 /* Can't get cache line size */
476 /* from NACA as it is being */
477 /* moved too. */
478
479 mtctr r0 /* put # words/line in ctr */
4803: addi r6,r6,8 /* copy a cache line */
481 ldx r0,r6,r4
482 stdx r0,r6,r3
483 bdnz 3b
484 dcbst r6,r3 /* write it to memory */
485 sync
486 icbi r6,r3 /* flush the icache line */
487 cmpld 0,r6,r5
488 blt 4b
489 sync
490 addi r5,r5,8
491 addi r6,r6,8
492 blr
493
494.align 8
495copy_to_here:
496
497#ifdef CONFIG_SMP
498#ifdef CONFIG_PPC_PMAC
499/*
500 * On PowerMac, secondary processors starts from the reset vector, which
501 * is temporarily turned into a call to one of the functions below.
502 */
503 .section ".text";
504 .align 2 ;
505
506 .globl __secondary_start_pmac_0
507__secondary_start_pmac_0:
508 /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
509 li r24,0
510 b 1f
511 li r24,1
512 b 1f
513 li r24,2
514 b 1f
515 li r24,3
5161:
517
518_GLOBAL(pmac_secondary_start)
519 /* turn on 64-bit mode */
520 bl .enable_64b_mode
521
522 li r0,0
523 mfspr r3,SPRN_HID4
524 rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
525 sync
526 mtspr SPRN_HID4,r3
527 isync
528 sync
529 slbia
530
531 /* get TOC pointer (real address) */
532 bl .relative_toc
533
534 /* Copy some CPU settings from CPU 0 */
535 bl .__restore_cpu_ppc970
536
537 /* pSeries do that early though I don't think we really need it */
538 mfmsr r3
539 ori r3,r3,MSR_RI
540 mtmsrd r3 /* RI on */
541
542 /* Set up a paca value for this processor. */
543 LOAD_REG_ADDR(r4,paca) /* Load paca pointer */
544 ld r4,0(r4) /* Get base vaddr of paca array */
545 mulli r13,r24,PACA_SIZE /* Calculate vaddr of right paca */
546 add r13,r13,r4 /* for this processor. */
547 SET_PACA(r13) /* Save vaddr of paca in an SPRG*/
548
549 /* Mark interrupts soft and hard disabled (they might be enabled
550 * in the PACA when doing hotplug)
551 */
552 li r0,0
553 stb r0,PACASOFTIRQEN(r13)
554 li r0,PACA_IRQ_HARD_DIS
555 stb r0,PACAIRQHAPPENED(r13)
556
557 /* Create a temp kernel stack for use before relocation is on. */
558 ld r1,PACAEMERGSP(r13)
559 subi r1,r1,STACK_FRAME_OVERHEAD
560
561 b __secondary_start
562
563#endif /* CONFIG_PPC_PMAC */
564
565/*
566 * This function is called after the master CPU has released the
567 * secondary processors. The execution environment is relocation off.
568 * The paca for this processor has the following fields initialized at
569 * this point:
570 * 1. Processor number
571 * 2. Segment table pointer (virtual address)
572 * On entry the following are set:
573 * r1 = stack pointer (real addr of temp stack)
574 * r24 = cpu# (in Linux terms)
575 * r13 = paca virtual address
576 * SPRG_PACA = paca virtual address
577 */
578 .section ".text";
579 .align 2 ;
580
581 .globl __secondary_start
582__secondary_start:
583 /* Set thread priority to MEDIUM */
584 HMT_MEDIUM
585
586 /* Initialize the kernel stack */
587 LOAD_REG_ADDR(r3, current_set)
588 sldi r28,r24,3 /* get current_set[cpu#] */
589 ldx r14,r3,r28
590 addi r14,r14,THREAD_SIZE-STACK_FRAME_OVERHEAD
591 std r14,PACAKSAVE(r13)
592
593 /* Do early setup for that CPU (stab, slb, hash table pointer) */
594 bl .early_setup_secondary
595
596 /*
597 * setup the new stack pointer, but *don't* use this until
598 * translation is on.
599 */
600 mr r1, r14
601
602 /* Clear backchain so we get nice backtraces */
603 li r7,0
604 mtlr r7
605
606 /* Mark interrupts soft and hard disabled (they might be enabled
607 * in the PACA when doing hotplug)
608 */
609 stb r7,PACASOFTIRQEN(r13)
610 li r0,PACA_IRQ_HARD_DIS
611 stb r0,PACAIRQHAPPENED(r13)
612
613 /* enable MMU and jump to start_secondary */
614 LOAD_REG_ADDR(r3, .start_secondary_prolog)
615 LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
616
617 mtspr SPRN_SRR0,r3
618 mtspr SPRN_SRR1,r4
619 RFI
620 b . /* prevent speculative execution */
621
622/*
623 * Running with relocation on at this point. All we want to do is
624 * zero the stack back-chain pointer and get the TOC virtual address
625 * before going into C code.
626 */
627_GLOBAL(start_secondary_prolog)
628 ld r2,PACATOC(r13)
629 li r3,0
630 std r3,0(r1) /* Zero the stack frame pointer */
631 bl .start_secondary
632 b .
633/*
634 * Reset stack pointer and call start_secondary
635 * to continue with online operation when woken up
636 * from cede in cpu offline.
637 */
638_GLOBAL(start_secondary_resume)
639 ld r1,PACAKSAVE(r13) /* Reload kernel stack pointer */
640 li r3,0
641 std r3,0(r1) /* Zero the stack frame pointer */
642 bl .start_secondary
643 b .
644#endif
645
646/*
647 * This subroutine clobbers r11 and r12
648 */
649_GLOBAL(enable_64b_mode)
650 mfmsr r11 /* grab the current MSR */
651#ifdef CONFIG_PPC_BOOK3E
652 oris r11,r11,0x8000 /* CM bit set, we'll set ICM later */
653 mtmsr r11
654#else /* CONFIG_PPC_BOOK3E */
655 li r12,(MSR_64BIT | MSR_ISF)@highest
656 sldi r12,r12,48
657 or r11,r11,r12
658 mtmsrd r11
659 isync
660#endif
661 blr
662
663/*
664 * This puts the TOC pointer into r2, offset by 0x8000 (as expected
665 * by the toolchain). It computes the correct value for wherever we
666 * are running at the moment, using position-independent code.
667 */
668_GLOBAL(relative_toc)
669 mflr r0
670 bcl 20,31,$+4
6710: mflr r11
672 ld r2,(p_toc - 0b)(r11)
673 add r2,r2,r11
674 mtlr r0
675 blr
676
677p_toc: .llong __toc_start + 0x8000 - 0b
678
679/*
680 * This is where the main kernel code starts.
681 */
682_INIT_STATIC(start_here_multiplatform)
683 /* set up the TOC (real address) */
684 bl .relative_toc
685
686 /* Clear out the BSS. It may have been done in prom_init,
687 * already but that's irrelevant since prom_init will soon
688 * be detached from the kernel completely. Besides, we need
689 * to clear it now for kexec-style entry.
690 */
691 LOAD_REG_ADDR(r11,__bss_stop)
692 LOAD_REG_ADDR(r8,__bss_start)
693 sub r11,r11,r8 /* bss size */
694 addi r11,r11,7 /* round up to an even double word */
695 srdi. r11,r11,3 /* shift right by 3 */
696 beq 4f
697 addi r8,r8,-8
698 li r0,0
699 mtctr r11 /* zero this many doublewords */
7003: stdu r0,8(r8)
701 bdnz 3b
7024:
703
704#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
705 /* Setup OPAL entry */
706 std r28,0(r11);
707 std r29,8(r11);
708#endif
709
710#ifndef CONFIG_PPC_BOOK3E
711 mfmsr r6
712 ori r6,r6,MSR_RI
713 mtmsrd r6 /* RI on */
714#endif
715
716#ifdef CONFIG_RELOCATABLE
717 /* Save the physical address we're running at in kernstart_addr */
718 LOAD_REG_ADDR(r4, kernstart_addr)
719 clrldi r0,r25,2
720 std r0,0(r4)
721#endif
722
723 /* The following gets the stack set up with the regs */
724 /* pointing to the real addr of the kernel stack. This is */
725 /* all done to support the C function call below which sets */
726 /* up the htab. This is done because we have relocated the */
727 /* kernel but are still running in real mode. */
728
729 LOAD_REG_ADDR(r3,init_thread_union)
730
731 /* set up a stack pointer */
732 addi r1,r3,THREAD_SIZE
733 li r0,0
734 stdu r0,-STACK_FRAME_OVERHEAD(r1)
735
736 /* Do very early kernel initializations, including initial hash table,
737 * stab and slb setup before we turn on relocation. */
738
739 /* Restore parameters passed from prom_init/kexec */
740 mr r3,r31
741 bl .early_setup /* also sets r13 and SPRG_PACA */
742
743 LOAD_REG_ADDR(r3, .start_here_common)
744 ld r4,PACAKMSR(r13)
745 mtspr SPRN_SRR0,r3
746 mtspr SPRN_SRR1,r4
747 RFI
748 b . /* prevent speculative execution */
749
750 /* This is where all platforms converge execution */
751_INIT_GLOBAL(start_here_common)
752 /* relocation is on at this point */
753 std r1,PACAKSAVE(r13)
754
755 /* Load the TOC (virtual address) */
756 ld r2,PACATOC(r13)
757
758 /* Do more system initializations in virtual mode */
759 bl .setup_system
760
761 /* Mark interrupts soft and hard disabled (they might be enabled
762 * in the PACA when doing hotplug)
763 */
764 li r0,0
765 stb r0,PACASOFTIRQEN(r13)
766 li r0,PACA_IRQ_HARD_DIS
767 stb r0,PACAIRQHAPPENED(r13)
768
769 /* Generic kernel entry */
770 bl .start_kernel
771
772 /* Not reached */
773 BUG_OPCODE
774
775/*
776 * We put a few things here that have to be page-aligned.
777 * This stuff goes at the beginning of the bss, which is page-aligned.
778 */
779 .section ".bss"
780
781 .align PAGE_SHIFT
782
783 .globl empty_zero_page
784empty_zero_page:
785 .space PAGE_SIZE
786
787 .globl swapper_pg_dir
788swapper_pg_dir:
789 .space PGD_TABLE_SIZE