xref: /linux/arch/powerpc/kernel/misc_64.S (revision 856e7c4b619af622d56b3b454f7bec32a170ac99)
1/*
2 * This file contains miscellaneous low-level functions.
3 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
6 * and Paul Mackerras.
7 * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
8 * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 */
16
17#include <linux/sys.h>
18#include <asm/unistd.h>
19#include <asm/errno.h>
20#include <asm/processor.h>
21#include <asm/page.h>
22#include <asm/cache.h>
23#include <asm/ppc_asm.h>
24#include <asm/asm-offsets.h>
25#include <asm/cputable.h>
26#include <asm/thread_info.h>
27#include <asm/kexec.h>
28#include <asm/ptrace.h>
29#include <asm/mmu.h>
30#include <asm/export.h>
31
32	.text
33
34_GLOBAL(call_do_softirq)
35	mflr	r0
36	std	r0,16(r1)
37	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
38	mr	r1,r3
39	bl	__do_softirq
40	ld	r1,0(r1)
41	ld	r0,16(r1)
42	mtlr	r0
43	blr
44
45_GLOBAL(call_do_irq)
46	mflr	r0
47	std	r0,16(r1)
48	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
49	mr	r1,r4
50	bl	__do_irq
51	ld	r1,0(r1)
52	ld	r0,16(r1)
53	mtlr	r0
54	blr
55
56	.section	".toc","aw"
57PPC64_CACHES:
58	.tc		ppc64_caches[TC],ppc64_caches
59	.section	".text"
60
61/*
62 * Write any modified data cache blocks out to memory
63 * and invalidate the corresponding instruction cache blocks.
64 *
65 * flush_icache_range(unsigned long start, unsigned long stop)
66 *
67 *   flush all bytes from start through stop-1 inclusive
68 */
69
70_GLOBAL_TOC(flush_icache_range)
71BEGIN_FTR_SECTION
72	PURGE_PREFETCHED_INS
73	blr
74END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
75/*
76 * Flush the data cache to memory
77 *
78 * Different systems have different cache line sizes
79 * and in some cases i-cache and d-cache line sizes differ from
80 * each other.
81 */
82 	ld	r10,PPC64_CACHES@toc(r2)
83	lwz	r7,DCACHEL1BLOCKSIZE(r10)/* Get cache block size */
84	addi	r5,r7,-1
85	andc	r6,r3,r5		/* round low to line bdy */
86	subf	r8,r6,r4		/* compute length */
87	add	r8,r8,r5		/* ensure we get enough */
88	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of cache block size */
89	srw.	r8,r8,r9		/* compute line count */
90	beqlr				/* nothing to do? */
91	mtctr	r8
921:	dcbst	0,r6
93	add	r6,r6,r7
94	bdnz	1b
95	sync
96
97/* Now invalidate the instruction cache */
98
99	lwz	r7,ICACHEL1BLOCKSIZE(r10)	/* Get Icache block size */
100	addi	r5,r7,-1
101	andc	r6,r3,r5		/* round low to line bdy */
102	subf	r8,r6,r4		/* compute length */
103	add	r8,r8,r5
104	lwz	r9,ICACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of Icache block size */
105	srw.	r8,r8,r9		/* compute line count */
106	beqlr				/* nothing to do? */
107	mtctr	r8
1082:	icbi	0,r6
109	add	r6,r6,r7
110	bdnz	2b
111	isync
112	blr
113_ASM_NOKPROBE_SYMBOL(flush_icache_range)
114EXPORT_SYMBOL(flush_icache_range)
115
116/*
117 * Like above, but only do the D-cache.
118 *
119 * flush_dcache_range(unsigned long start, unsigned long stop)
120 *
121 *    flush all bytes from start to stop-1 inclusive
122 */
123_GLOBAL_TOC(flush_dcache_range)
124
125/*
126 * Flush the data cache to memory
127 *
128 * Different systems have different cache line sizes
129 */
130 	ld	r10,PPC64_CACHES@toc(r2)
131	lwz	r7,DCACHEL1BLOCKSIZE(r10)	/* Get dcache block size */
132	addi	r5,r7,-1
133	andc	r6,r3,r5		/* round low to line bdy */
134	subf	r8,r6,r4		/* compute length */
135	add	r8,r8,r5		/* ensure we get enough */
136	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of dcache block size */
137	srw.	r8,r8,r9		/* compute line count */
138	beqlr				/* nothing to do? */
139	mtctr	r8
1400:	dcbst	0,r6
141	add	r6,r6,r7
142	bdnz	0b
143	sync
144	blr
145EXPORT_SYMBOL(flush_dcache_range)
146
147_GLOBAL(flush_inval_dcache_range)
148 	ld	r10,PPC64_CACHES@toc(r2)
149	lwz	r7,DCACHEL1BLOCKSIZE(r10)	/* Get dcache block size */
150	addi	r5,r7,-1
151	andc	r6,r3,r5		/* round low to line bdy */
152	subf	r8,r6,r4		/* compute length */
153	add	r8,r8,r5		/* ensure we get enough */
154	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)/* Get log-2 of dcache block size */
155	srw.	r8,r8,r9		/* compute line count */
156	beqlr				/* nothing to do? */
157	sync
158	isync
159	mtctr	r8
1600:	dcbf	0,r6
161	add	r6,r6,r7
162	bdnz	0b
163	sync
164	isync
165	blr
166
167
168/*
169 * Flush a particular page from the data cache to RAM.
170 * Note: this is necessary because the instruction cache does *not*
171 * snoop from the data cache.
172 *
173 *	void __flush_dcache_icache(void *page)
174 */
175_GLOBAL(__flush_dcache_icache)
176/*
177 * Flush the data cache to memory
178 *
179 * Different systems have different cache line sizes
180 */
181
182BEGIN_FTR_SECTION
183	PURGE_PREFETCHED_INS
184	blr
185END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
186
187/* Flush the dcache */
188 	ld	r7,PPC64_CACHES@toc(r2)
189	clrrdi	r3,r3,PAGE_SHIFT           	    /* Page align */
190	lwz	r4,DCACHEL1BLOCKSPERPAGE(r7)	/* Get # dcache blocks per page */
191	lwz	r5,DCACHEL1BLOCKSIZE(r7)	/* Get dcache block size */
192	mr	r6,r3
193	mtctr	r4
1940:	dcbst	0,r6
195	add	r6,r6,r5
196	bdnz	0b
197	sync
198
199/* Now invalidate the icache */
200
201	lwz	r4,ICACHEL1BLOCKSPERPAGE(r7)	/* Get # icache blocks per page */
202	lwz	r5,ICACHEL1BLOCKSIZE(r7)	/* Get icache block size */
203	mtctr	r4
2041:	icbi	0,r3
205	add	r3,r3,r5
206	bdnz	1b
207	isync
208	blr
209
210_GLOBAL(__bswapdi2)
211EXPORT_SYMBOL(__bswapdi2)
212	srdi	r8,r3,32
213	rlwinm	r7,r3,8,0xffffffff
214	rlwimi	r7,r3,24,0,7
215	rlwinm	r9,r8,8,0xffffffff
216	rlwimi	r7,r3,24,16,23
217	rlwimi	r9,r8,24,0,7
218	rlwimi	r9,r8,24,16,23
219	sldi	r7,r7,32
220	or	r3,r7,r9
221	blr
222
223
224#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
225_GLOBAL(rmci_on)
226	sync
227	isync
228	li	r3,0x100
229	rldicl	r3,r3,32,0
230	mfspr	r5,SPRN_HID4
231	or	r5,r5,r3
232	sync
233	mtspr	SPRN_HID4,r5
234	isync
235	slbia
236	isync
237	sync
238	blr
239
240_GLOBAL(rmci_off)
241	sync
242	isync
243	li	r3,0x100
244	rldicl	r3,r3,32,0
245	mfspr	r5,SPRN_HID4
246	andc	r5,r5,r3
247	sync
248	mtspr	SPRN_HID4,r5
249	isync
250	slbia
251	isync
252	sync
253	blr
254#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
255
256#if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
257
258/*
259 * Do an IO access in real mode
260 */
261_GLOBAL(real_readb)
262	mfmsr	r7
263	ori	r0,r7,MSR_DR
264	xori	r0,r0,MSR_DR
265	sync
266	mtmsrd	r0
267	sync
268	isync
269	mfspr	r6,SPRN_HID4
270	rldicl	r5,r6,32,0
271	ori	r5,r5,0x100
272	rldicl	r5,r5,32,0
273	sync
274	mtspr	SPRN_HID4,r5
275	isync
276	slbia
277	isync
278	lbz	r3,0(r3)
279	sync
280	mtspr	SPRN_HID4,r6
281	isync
282	slbia
283	isync
284	mtmsrd	r7
285	sync
286	isync
287	blr
288
289	/*
290 * Do an IO access in real mode
291 */
292_GLOBAL(real_writeb)
293	mfmsr	r7
294	ori	r0,r7,MSR_DR
295	xori	r0,r0,MSR_DR
296	sync
297	mtmsrd	r0
298	sync
299	isync
300	mfspr	r6,SPRN_HID4
301	rldicl	r5,r6,32,0
302	ori	r5,r5,0x100
303	rldicl	r5,r5,32,0
304	sync
305	mtspr	SPRN_HID4,r5
306	isync
307	slbia
308	isync
309	stb	r3,0(r4)
310	sync
311	mtspr	SPRN_HID4,r6
312	isync
313	slbia
314	isync
315	mtmsrd	r7
316	sync
317	isync
318	blr
319#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */
320
321#ifdef CONFIG_PPC_PASEMI
322
323_GLOBAL(real_205_readb)
324	mfmsr	r7
325	ori	r0,r7,MSR_DR
326	xori	r0,r0,MSR_DR
327	sync
328	mtmsrd	r0
329	sync
330	isync
331	LBZCIX(R3,R0,R3)
332	isync
333	mtmsrd	r7
334	sync
335	isync
336	blr
337
338_GLOBAL(real_205_writeb)
339	mfmsr	r7
340	ori	r0,r7,MSR_DR
341	xori	r0,r0,MSR_DR
342	sync
343	mtmsrd	r0
344	sync
345	isync
346	STBCIX(R3,R0,R4)
347	isync
348	mtmsrd	r7
349	sync
350	isync
351	blr
352
353#endif /* CONFIG_PPC_PASEMI */
354
355
356#if defined(CONFIG_CPU_FREQ_PMAC64) || defined(CONFIG_CPU_FREQ_MAPLE)
357/*
358 * SCOM access functions for 970 (FX only for now)
359 *
360 * unsigned long scom970_read(unsigned int address);
361 * void scom970_write(unsigned int address, unsigned long value);
362 *
363 * The address passed in is the 24 bits register address. This code
364 * is 970 specific and will not check the status bits, so you should
365 * know what you are doing.
366 */
367_GLOBAL(scom970_read)
368	/* interrupts off */
369	mfmsr	r4
370	ori	r0,r4,MSR_EE
371	xori	r0,r0,MSR_EE
372	mtmsrd	r0,1
373
374	/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
375	 * (including parity). On current CPUs they must be 0'd,
376	 * and finally or in RW bit
377	 */
378	rlwinm	r3,r3,8,0,15
379	ori	r3,r3,0x8000
380
381	/* do the actual scom read */
382	sync
383	mtspr	SPRN_SCOMC,r3
384	isync
385	mfspr	r3,SPRN_SCOMD
386	isync
387	mfspr	r0,SPRN_SCOMC
388	isync
389
390	/* XXX:	fixup result on some buggy 970's (ouch ! we lost a bit, bah
391	 * that's the best we can do). Not implemented yet as we don't use
392	 * the scom on any of the bogus CPUs yet, but may have to be done
393	 * ultimately
394	 */
395
396	/* restore interrupts */
397	mtmsrd	r4,1
398	blr
399
400
401_GLOBAL(scom970_write)
402	/* interrupts off */
403	mfmsr	r5
404	ori	r0,r5,MSR_EE
405	xori	r0,r0,MSR_EE
406	mtmsrd	r0,1
407
408	/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
409	 * (including parity). On current CPUs they must be 0'd.
410	 */
411
412	rlwinm	r3,r3,8,0,15
413
414	sync
415	mtspr	SPRN_SCOMD,r4      /* write data */
416	isync
417	mtspr	SPRN_SCOMC,r3      /* write command */
418	isync
419	mfspr	3,SPRN_SCOMC
420	isync
421
422	/* restore interrupts */
423	mtmsrd	r5,1
424	blr
425#endif /* CONFIG_CPU_FREQ_PMAC64 || CONFIG_CPU_FREQ_MAPLE */
426
427/* kexec_wait(phys_cpu)
428 *
429 * wait for the flag to change, indicating this kernel is going away but
430 * the slave code for the next one is at addresses 0 to 100.
431 *
432 * This is used by all slaves, even those that did not find a matching
433 * paca in the secondary startup code.
434 *
435 * Physical (hardware) cpu id should be in r3.
436 */
437_GLOBAL(kexec_wait)
438	bl	1f
4391:	mflr	r5
440	addi	r5,r5,kexec_flag-1b
441
44299:	HMT_LOW
443#ifdef CONFIG_KEXEC_CORE	/* use no memory without kexec */
444	lwz	r4,0(r5)
445	cmpwi	0,r4,0
446	beq	99b
447#ifdef CONFIG_PPC_BOOK3S_64
448	li	r10,0x60
449	mfmsr	r11
450	clrrdi	r11,r11,1	/* Clear MSR_LE */
451	mtsrr0	r10
452	mtsrr1	r11
453	rfid
454#else
455	/* Create TLB entry in book3e_secondary_core_init */
456	li	r4,0
457	ba	0x60
458#endif
459#endif
460
461/* this can be in text because we won't change it until we are
462 * running in real anyways
463 */
464kexec_flag:
465	.long	0
466
467
468#ifdef CONFIG_KEXEC_CORE
469#ifdef CONFIG_PPC_BOOK3E
470/*
471 * BOOK3E has no real MMU mode, so we have to setup the initial TLB
472 * for a core to identity map v:0 to p:0.  This current implementation
473 * assumes that 1G is enough for kexec.
474 */
475kexec_create_tlb:
476	/*
477	 * Invalidate all non-IPROT TLB entries to avoid any TLB conflict.
478	 * IPROT TLB entries should be >= PAGE_OFFSET and thus not conflict.
479	 */
480	PPC_TLBILX_ALL(0,R0)
481	sync
482	isync
483
484	mfspr	r10,SPRN_TLB1CFG
485	andi.	r10,r10,TLBnCFG_N_ENTRY	/* Extract # entries */
486	subi	r10,r10,1	/* Last entry: no conflict with kernel text */
487	lis	r9,MAS0_TLBSEL(1)@h
488	rlwimi	r9,r10,16,4,15		/* Setup MAS0 = TLBSEL | ESEL(r9) */
489
490/* Set up a temp identity mapping v:0 to p:0 and return to it. */
491#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
492#define M_IF_NEEDED	MAS2_M
493#else
494#define M_IF_NEEDED	0
495#endif
496	mtspr	SPRN_MAS0,r9
497
498	lis	r9,(MAS1_VALID|MAS1_IPROT)@h
499	ori	r9,r9,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
500	mtspr	SPRN_MAS1,r9
501
502	LOAD_REG_IMMEDIATE(r9, 0x0 | M_IF_NEEDED)
503	mtspr	SPRN_MAS2,r9
504
505	LOAD_REG_IMMEDIATE(r9, 0x0 | MAS3_SR | MAS3_SW | MAS3_SX)
506	mtspr	SPRN_MAS3,r9
507	li	r9,0
508	mtspr	SPRN_MAS7,r9
509
510	tlbwe
511	isync
512	blr
513#endif
514
515/* kexec_smp_wait(void)
516 *
517 * call with interrupts off
518 * note: this is a terminal routine, it does not save lr
519 *
520 * get phys id from paca
521 * switch to real mode
522 * mark the paca as no longer used
523 * join other cpus in kexec_wait(phys_id)
524 */
525_GLOBAL(kexec_smp_wait)
526	lhz	r3,PACAHWCPUID(r13)
527	bl	real_mode
528
529	li	r4,KEXEC_STATE_REAL_MODE
530	stb	r4,PACAKEXECSTATE(r13)
531	SYNC
532
533	b	kexec_wait
534
535/*
536 * switch to real mode (turn mmu off)
537 * we use the early kernel trick that the hardware ignores bits
538 * 0 and 1 (big endian) of the effective address in real mode
539 *
540 * don't overwrite r3 here, it is live for kexec_wait above.
541 */
542real_mode:	/* assume normal blr return */
543#ifdef CONFIG_PPC_BOOK3E
544	/* Create an identity mapping. */
545	b	kexec_create_tlb
546#else
5471:	li	r9,MSR_RI
548	li	r10,MSR_DR|MSR_IR
549	mflr	r11		/* return address to SRR0 */
550	mfmsr	r12
551	andc	r9,r12,r9
552	andc	r10,r12,r10
553
554	mtmsrd	r9,1
555	mtspr	SPRN_SRR1,r10
556	mtspr	SPRN_SRR0,r11
557	rfid
558#endif
559
560/*
561 * kexec_sequence(newstack, start, image, control, clear_all(),
562	          copy_with_mmu_off)
563 *
564 * does the grungy work with stack switching and real mode switches
565 * also does simple calls to other code
566 */
567
568_GLOBAL(kexec_sequence)
569	mflr	r0
570	std	r0,16(r1)
571
572	/* switch stacks to newstack -- &kexec_stack.stack */
573	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
574	mr	r1,r3
575
576	li	r0,0
577	std	r0,16(r1)
578
579BEGIN_FTR_SECTION
580	/*
581	 * This is the best time to turn AMR/IAMR off.
582	 * key 0 is used in radix for supervisor<->user
583	 * protection, but on hash key 0 is reserved
584	 * ideally we want to enter with a clean state.
585	 * NOTE, we rely on r0 being 0 from above.
586	 */
587	mtspr	SPRN_IAMR,r0
588BEGIN_FTR_SECTION_NESTED(42)
589	mtspr	SPRN_AMOR,r0
590END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42)
591END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
592
593	/* save regs for local vars on new stack.
594	 * yes, we won't go back, but ...
595	 */
596	std	r31,-8(r1)
597	std	r30,-16(r1)
598	std	r29,-24(r1)
599	std	r28,-32(r1)
600	std	r27,-40(r1)
601	std	r26,-48(r1)
602	std	r25,-56(r1)
603
604	stdu	r1,-STACK_FRAME_OVERHEAD-64(r1)
605
606	/* save args into preserved regs */
607	mr	r31,r3			/* newstack (both) */
608	mr	r30,r4			/* start (real) */
609	mr	r29,r5			/* image (virt) */
610	mr	r28,r6			/* control, unused */
611	mr	r27,r7			/* clear_all() fn desc */
612	mr	r26,r8			/* copy_with_mmu_off */
613	lhz	r25,PACAHWCPUID(r13)	/* get our phys cpu from paca */
614
615	/* disable interrupts, we are overwriting kernel data next */
616#ifdef CONFIG_PPC_BOOK3E
617	wrteei	0
618#else
619	mfmsr	r3
620	rlwinm	r3,r3,0,17,15
621	mtmsrd	r3,1
622#endif
623
624	/* We need to turn the MMU off unless we are in hash mode
625	 * under a hypervisor
626	 */
627	cmpdi	r26,0
628	beq	1f
629	bl	real_mode
6301:
631	/* copy dest pages, flush whole dest image */
632	mr	r3,r29
633	bl	kexec_copy_flush	/* (image) */
634
635	/* turn off mmu now if not done earlier */
636	cmpdi	r26,0
637	bne	1f
638	bl	real_mode
639
640	/* copy  0x100 bytes starting at start to 0 */
6411:	li	r3,0
642	mr	r4,r30		/* start, aka phys mem offset */
643	li	r5,0x100
644	li	r6,0
645	bl	copy_and_flush	/* (dest, src, copy limit, start offset) */
6461:	/* assume normal blr return */
647
648	/* release other cpus to the new kernel secondary start at 0x60 */
649	mflr	r5
650	li	r6,1
651	stw	r6,kexec_flag-1b(5)
652
653	cmpdi	r27,0
654	beq	1f
655
656	/* clear out hardware hash page table and tlb */
657#ifdef PPC64_ELF_ABI_v1
658	ld	r12,0(r27)		/* deref function descriptor */
659#else
660	mr	r12,r27
661#endif
662	mtctr	r12
663	bctrl				/* mmu_hash_ops.hpte_clear_all(void); */
664
665/*
666 *   kexec image calling is:
667 *      the first 0x100 bytes of the entry point are copied to 0
668 *
669 *      all slaves branch to slave = 0x60 (absolute)
670 *              slave(phys_cpu_id);
671 *
672 *      master goes to start = entry point
673 *              start(phys_cpu_id, start, 0);
674 *
675 *
676 *   a wrapper is needed to call existing kernels, here is an approximate
677 *   description of one method:
678 *
679 * v2: (2.6.10)
680 *   start will be near the boot_block (maybe 0x100 bytes before it?)
681 *   it will have a 0x60, which will b to boot_block, where it will wait
682 *   and 0 will store phys into struct boot-block and load r3 from there,
683 *   copy kernel 0-0x100 and tell slaves to back down to 0x60 again
684 *
685 * v1: (2.6.9)
686 *    boot block will have all cpus scanning device tree to see if they
687 *    are the boot cpu ?????
688 *    other device tree differences (prop sizes, va vs pa, etc)...
689 */
6901:	mr	r3,r25	# my phys cpu
691	mr	r4,r30	# start, aka phys mem offset
692	mtlr	4
693	li	r5,0
694	blr	/* image->start(physid, image->start, 0); */
695#endif /* CONFIG_KEXEC_CORE */
696