xref: /openbmc/linux/arch/powerpc/kernel/misc_64.S (revision b627b4ed) 
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
28	.text
29
30#ifdef CONFIG_IRQSTACKS
31_GLOBAL(call_do_softirq)
32	mflr	r0
33	std	r0,16(r1)
34	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
35	mr	r1,r3
36	bl	.__do_softirq
37	ld	r1,0(r1)
38	ld	r0,16(r1)
39	mtlr	r0
40	blr
41
42_GLOBAL(call_handle_irq)
43	ld	r8,0(r6)
44	mflr	r0
45	std	r0,16(r1)
46	mtctr	r8
47	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r5)
48	mr	r1,r5
49	bctrl
50	ld	r1,0(r1)
51	ld	r0,16(r1)
52	mtlr	r0
53	blr
54#endif /* CONFIG_IRQSTACKS */
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_KPROBE(__flush_icache_range)
71
72/*
73 * Flush the data cache to memory
74 *
75 * Different systems have different cache line sizes
76 * and in some cases i-cache and d-cache line sizes differ from
77 * each other.
78 */
79 	ld	r10,PPC64_CACHES@toc(r2)
80	lwz	r7,DCACHEL1LINESIZE(r10)/* Get cache line size */
81	addi	r5,r7,-1
82	andc	r6,r3,r5		/* round low to line bdy */
83	subf	r8,r6,r4		/* compute length */
84	add	r8,r8,r5		/* ensure we get enough */
85	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of cache line size */
86	srw.	r8,r8,r9		/* compute line count */
87	beqlr				/* nothing to do? */
88	mtctr	r8
891:	dcbst	0,r6
90	add	r6,r6,r7
91	bdnz	1b
92	sync
93
94/* Now invalidate the instruction cache */
95
96	lwz	r7,ICACHEL1LINESIZE(r10)	/* Get Icache line size */
97	addi	r5,r7,-1
98	andc	r6,r3,r5		/* round low to line bdy */
99	subf	r8,r6,r4		/* compute length */
100	add	r8,r8,r5
101	lwz	r9,ICACHEL1LOGLINESIZE(r10)	/* Get log-2 of Icache line size */
102	srw.	r8,r8,r9		/* compute line count */
103	beqlr				/* nothing to do? */
104	mtctr	r8
1052:	icbi	0,r6
106	add	r6,r6,r7
107	bdnz	2b
108	isync
109	blr
110	.previous .text
111/*
112 * Like above, but only do the D-cache.
113 *
114 * flush_dcache_range(unsigned long start, unsigned long stop)
115 *
116 *    flush all bytes from start to stop-1 inclusive
117 */
118_GLOBAL(flush_dcache_range)
119
120/*
121 * Flush the data cache to memory
122 *
123 * Different systems have different cache line sizes
124 */
125 	ld	r10,PPC64_CACHES@toc(r2)
126	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
127	addi	r5,r7,-1
128	andc	r6,r3,r5		/* round low to line bdy */
129	subf	r8,r6,r4		/* compute length */
130	add	r8,r8,r5		/* ensure we get enough */
131	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of dcache line size */
132	srw.	r8,r8,r9		/* compute line count */
133	beqlr				/* nothing to do? */
134	mtctr	r8
1350:	dcbst	0,r6
136	add	r6,r6,r7
137	bdnz	0b
138	sync
139	blr
140
141/*
142 * Like above, but works on non-mapped physical addresses.
143 * Use only for non-LPAR setups ! It also assumes real mode
144 * is cacheable. Used for flushing out the DART before using
145 * it as uncacheable memory
146 *
147 * flush_dcache_phys_range(unsigned long start, unsigned long stop)
148 *
149 *    flush all bytes from start to stop-1 inclusive
150 */
151_GLOBAL(flush_dcache_phys_range)
152 	ld	r10,PPC64_CACHES@toc(r2)
153	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
154	addi	r5,r7,-1
155	andc	r6,r3,r5		/* round low to line bdy */
156	subf	r8,r6,r4		/* compute length */
157	add	r8,r8,r5		/* ensure we get enough */
158	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of dcache line size */
159	srw.	r8,r8,r9		/* compute line count */
160	beqlr				/* nothing to do? */
161	mfmsr	r5			/* Disable MMU Data Relocation */
162	ori	r0,r5,MSR_DR
163	xori	r0,r0,MSR_DR
164	sync
165	mtmsr	r0
166	sync
167	isync
168	mtctr	r8
1690:	dcbst	0,r6
170	add	r6,r6,r7
171	bdnz	0b
172	sync
173	isync
174	mtmsr	r5			/* Re-enable MMU Data Relocation */
175	sync
176	isync
177	blr
178
179_GLOBAL(flush_inval_dcache_range)
180 	ld	r10,PPC64_CACHES@toc(r2)
181	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
182	addi	r5,r7,-1
183	andc	r6,r3,r5		/* round low to line bdy */
184	subf	r8,r6,r4		/* compute length */
185	add	r8,r8,r5		/* ensure we get enough */
186	lwz	r9,DCACHEL1LOGLINESIZE(r10)/* Get log-2 of dcache line size */
187	srw.	r8,r8,r9		/* compute line count */
188	beqlr				/* nothing to do? */
189	sync
190	isync
191	mtctr	r8
1920:	dcbf	0,r6
193	add	r6,r6,r7
194	bdnz	0b
195	sync
196	isync
197	blr
198
199
200/*
201 * Flush a particular page from the data cache to RAM.
202 * Note: this is necessary because the instruction cache does *not*
203 * snoop from the data cache.
204 *
205 *	void __flush_dcache_icache(void *page)
206 */
207_GLOBAL(__flush_dcache_icache)
208/*
209 * Flush the data cache to memory
210 *
211 * Different systems have different cache line sizes
212 */
213
214/* Flush the dcache */
215 	ld	r7,PPC64_CACHES@toc(r2)
216	clrrdi	r3,r3,PAGE_SHIFT           	    /* Page align */
217	lwz	r4,DCACHEL1LINESPERPAGE(r7)	/* Get # dcache lines per page */
218	lwz	r5,DCACHEL1LINESIZE(r7)		/* Get dcache line size */
219	mr	r6,r3
220	mtctr	r4
2210:	dcbst	0,r6
222	add	r6,r6,r5
223	bdnz	0b
224	sync
225
226/* Now invalidate the icache */
227
228	lwz	r4,ICACHEL1LINESPERPAGE(r7)	/* Get # icache lines per page */
229	lwz	r5,ICACHEL1LINESIZE(r7)		/* Get icache line size */
230	mtctr	r4
2311:	icbi	0,r3
232	add	r3,r3,r5
233	bdnz	1b
234	isync
235	blr
236
237
238#if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
239/*
240 * Do an IO access in real mode
241 */
242_GLOBAL(real_readb)
243	mfmsr	r7
244	ori	r0,r7,MSR_DR
245	xori	r0,r0,MSR_DR
246	sync
247	mtmsrd	r0
248	sync
249	isync
250	mfspr	r6,SPRN_HID4
251	rldicl	r5,r6,32,0
252	ori	r5,r5,0x100
253	rldicl	r5,r5,32,0
254	sync
255	mtspr	SPRN_HID4,r5
256	isync
257	slbia
258	isync
259	lbz	r3,0(r3)
260	sync
261	mtspr	SPRN_HID4,r6
262	isync
263	slbia
264	isync
265	mtmsrd	r7
266	sync
267	isync
268	blr
269
270	/*
271 * Do an IO access in real mode
272 */
273_GLOBAL(real_writeb)
274	mfmsr	r7
275	ori	r0,r7,MSR_DR
276	xori	r0,r0,MSR_DR
277	sync
278	mtmsrd	r0
279	sync
280	isync
281	mfspr	r6,SPRN_HID4
282	rldicl	r5,r6,32,0
283	ori	r5,r5,0x100
284	rldicl	r5,r5,32,0
285	sync
286	mtspr	SPRN_HID4,r5
287	isync
288	slbia
289	isync
290	stb	r3,0(r4)
291	sync
292	mtspr	SPRN_HID4,r6
293	isync
294	slbia
295	isync
296	mtmsrd	r7
297	sync
298	isync
299	blr
300#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */
301
302#ifdef CONFIG_PPC_PASEMI
303
304/* No support in all binutils for these yet, so use defines */
305#define LBZCIX(RT,RA,RB)  .long (0x7c0006aa|(RT<<21)|(RA<<16)|(RB << 11))
306#define STBCIX(RS,RA,RB)  .long (0x7c0007aa|(RS<<21)|(RA<<16)|(RB << 11))
307
308
309_GLOBAL(real_205_readb)
310	mfmsr	r7
311	ori	r0,r7,MSR_DR
312	xori	r0,r0,MSR_DR
313	sync
314	mtmsrd	r0
315	sync
316	isync
317	LBZCIX(r3,0,r3)
318	isync
319	mtmsrd	r7
320	sync
321	isync
322	blr
323
324_GLOBAL(real_205_writeb)
325	mfmsr	r7
326	ori	r0,r7,MSR_DR
327	xori	r0,r0,MSR_DR
328	sync
329	mtmsrd	r0
330	sync
331	isync
332	STBCIX(r3,0,r4)
333	isync
334	mtmsrd	r7
335	sync
336	isync
337	blr
338
339#endif /* CONFIG_PPC_PASEMI */
340
341
342#ifdef CONFIG_CPU_FREQ_PMAC64
343/*
344 * SCOM access functions for 970 (FX only for now)
345 *
346 * unsigned long scom970_read(unsigned int address);
347 * void scom970_write(unsigned int address, unsigned long value);
348 *
349 * The address passed in is the 24 bits register address. This code
350 * is 970 specific and will not check the status bits, so you should
351 * know what you are doing.
352 */
353_GLOBAL(scom970_read)
354	/* interrupts off */
355	mfmsr	r4
356	ori	r0,r4,MSR_EE
357	xori	r0,r0,MSR_EE
358	mtmsrd	r0,1
359
360	/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
361	 * (including parity). On current CPUs they must be 0'd,
362	 * and finally or in RW bit
363	 */
364	rlwinm	r3,r3,8,0,15
365	ori	r3,r3,0x8000
366
367	/* do the actual scom read */
368	sync
369	mtspr	SPRN_SCOMC,r3
370	isync
371	mfspr	r3,SPRN_SCOMD
372	isync
373	mfspr	r0,SPRN_SCOMC
374	isync
375
376	/* XXX:	fixup result on some buggy 970's (ouch ! we lost a bit, bah
377	 * that's the best we can do). Not implemented yet as we don't use
378	 * the scom on any of the bogus CPUs yet, but may have to be done
379	 * ultimately
380	 */
381
382	/* restore interrupts */
383	mtmsrd	r4,1
384	blr
385
386
387_GLOBAL(scom970_write)
388	/* interrupts off */
389	mfmsr	r5
390	ori	r0,r5,MSR_EE
391	xori	r0,r0,MSR_EE
392	mtmsrd	r0,1
393
394	/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
395	 * (including parity). On current CPUs they must be 0'd.
396	 */
397
398	rlwinm	r3,r3,8,0,15
399
400	sync
401	mtspr	SPRN_SCOMD,r4      /* write data */
402	isync
403	mtspr	SPRN_SCOMC,r3      /* write command */
404	isync
405	mfspr	3,SPRN_SCOMC
406	isync
407
408	/* restore interrupts */
409	mtmsrd	r5,1
410	blr
411#endif /* CONFIG_CPU_FREQ_PMAC64 */
412
413
414/*
415 * Create a kernel thread
416 *   kernel_thread(fn, arg, flags)
417 */
418_GLOBAL(kernel_thread)
419	std	r29,-24(r1)
420	std	r30,-16(r1)
421	stdu	r1,-STACK_FRAME_OVERHEAD(r1)
422	mr	r29,r3
423	mr	r30,r4
424	ori	r3,r5,CLONE_VM	/* flags */
425	oris	r3,r3,(CLONE_UNTRACED>>16)
426	li	r4,0		/* new sp (unused) */
427	li	r0,__NR_clone
428	sc
429	bns+	1f		/* did system call indicate error? */
430	neg	r3,r3		/* if so, make return code negative */
4311:	cmpdi	0,r3,0		/* parent or child? */
432	bne	2f		/* return if parent */
433	li	r0,0
434	stdu	r0,-STACK_FRAME_OVERHEAD(r1)
435	ld	r2,8(r29)
436	ld	r29,0(r29)
437	mtlr	r29              /* fn addr in lr */
438	mr	r3,r30	        /* load arg and call fn */
439	blrl
440	li	r0,__NR_exit	/* exit after child exits */
441        li	r3,0
442	sc
4432:	addi	r1,r1,STACK_FRAME_OVERHEAD
444	ld	r29,-24(r1)
445	ld	r30,-16(r1)
446	blr
447
448/*
449 * disable_kernel_fp()
450 * Disable the FPU.
451 */
452_GLOBAL(disable_kernel_fp)
453	mfmsr	r3
454	rldicl	r0,r3,(63-MSR_FP_LG),1
455	rldicl	r3,r0,(MSR_FP_LG+1),0
456	mtmsrd	r3			/* disable use of fpu now */
457	isync
458	blr
459
460#ifdef CONFIG_ALTIVEC
461
462#if 0 /* this has no callers for now */
463/*
464 * disable_kernel_altivec()
465 * Disable the VMX.
466 */
467_GLOBAL(disable_kernel_altivec)
468	mfmsr	r3
469	rldicl	r0,r3,(63-MSR_VEC_LG),1
470	rldicl	r3,r0,(MSR_VEC_LG+1),0
471	mtmsrd	r3			/* disable use of VMX now */
472	isync
473	blr
474#endif /* 0 */
475
476/*
477 * giveup_altivec(tsk)
478 * Disable VMX for the task given as the argument,
479 * and save the vector registers in its thread_struct.
480 * Enables the VMX for use in the kernel on return.
481 */
482_GLOBAL(giveup_altivec)
483	mfmsr	r5
484	oris	r5,r5,MSR_VEC@h
485	mtmsrd	r5			/* enable use of VMX now */
486	isync
487	cmpdi	0,r3,0
488	beqlr-				/* if no previous owner, done */
489	addi	r3,r3,THREAD		/* want THREAD of task */
490	ld	r5,PT_REGS(r3)
491	cmpdi	0,r5,0
492	SAVE_32VRS(0,r4,r3)
493	mfvscr	vr0
494	li	r4,THREAD_VSCR
495	stvx	vr0,r4,r3
496	beq	1f
497	ld	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
498#ifdef CONFIG_VSX
499BEGIN_FTR_SECTION
500	lis	r3,(MSR_VEC|MSR_VSX)@h
501FTR_SECTION_ELSE
502	lis	r3,MSR_VEC@h
503ALT_FTR_SECTION_END_IFSET(CPU_FTR_VSX)
504#else
505	lis	r3,MSR_VEC@h
506#endif
507	andc	r4,r4,r3		/* disable FP for previous task */
508	std	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
5091:
510#ifndef CONFIG_SMP
511	li	r5,0
512	ld	r4,last_task_used_altivec@got(r2)
513	std	r5,0(r4)
514#endif /* CONFIG_SMP */
515	blr
516
517#endif /* CONFIG_ALTIVEC */
518
519#ifdef CONFIG_VSX
520/*
521 * __giveup_vsx(tsk)
522 * Disable VSX for the task given as the argument.
523 * Does NOT save vsx registers.
524 * Enables the VSX for use in the kernel on return.
525 */
526_GLOBAL(__giveup_vsx)
527	mfmsr	r5
528	oris	r5,r5,MSR_VSX@h
529	mtmsrd	r5			/* enable use of VSX now */
530	isync
531
532	cmpdi	0,r3,0
533	beqlr-				/* if no previous owner, done */
534	addi	r3,r3,THREAD		/* want THREAD of task */
535	ld	r5,PT_REGS(r3)
536	cmpdi	0,r5,0
537	beq	1f
538	ld	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
539	lis	r3,MSR_VSX@h
540	andc	r4,r4,r3		/* disable VSX for previous task */
541	std	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
5421:
543#ifndef CONFIG_SMP
544	li	r5,0
545	ld	r4,last_task_used_vsx@got(r2)
546	std	r5,0(r4)
547#endif /* CONFIG_SMP */
548	blr
549
550#endif /* CONFIG_VSX */
551
552/* kexec_wait(phys_cpu)
553 *
554 * wait for the flag to change, indicating this kernel is going away but
555 * the slave code for the next one is at addresses 0 to 100.
556 *
557 * This is used by all slaves.
558 *
559 * Physical (hardware) cpu id should be in r3.
560 */
561_GLOBAL(kexec_wait)
562	bl	1f
5631:	mflr	r5
564	addi	r5,r5,kexec_flag-1b
565
56699:	HMT_LOW
567#ifdef CONFIG_KEXEC		/* use no memory without kexec */
568	lwz	r4,0(r5)
569	cmpwi	0,r4,0
570	bnea	0x60
571#endif
572	b	99b
573
574/* this can be in text because we won't change it until we are
575 * running in real anyways
576 */
577kexec_flag:
578	.long	0
579
580
581#ifdef CONFIG_KEXEC
582
583/* kexec_smp_wait(void)
584 *
585 * call with interrupts off
586 * note: this is a terminal routine, it does not save lr
587 *
588 * get phys id from paca
589 * set paca id to -1 to say we got here
590 * switch to real mode
591 * join other cpus in kexec_wait(phys_id)
592 */
593_GLOBAL(kexec_smp_wait)
594	lhz	r3,PACAHWCPUID(r13)
595	li	r4,-1
596	sth	r4,PACAHWCPUID(r13)	/* let others know we left */
597	bl	real_mode
598	b	.kexec_wait
599
600/*
601 * switch to real mode (turn mmu off)
602 * we use the early kernel trick that the hardware ignores bits
603 * 0 and 1 (big endian) of the effective address in real mode
604 *
605 * don't overwrite r3 here, it is live for kexec_wait above.
606 */
607real_mode:	/* assume normal blr return */
6081:	li	r9,MSR_RI
609	li	r10,MSR_DR|MSR_IR
610	mflr	r11		/* return address to SRR0 */
611	mfmsr	r12
612	andc	r9,r12,r9
613	andc	r10,r12,r10
614
615	mtmsrd	r9,1
616	mtspr	SPRN_SRR1,r10
617	mtspr	SPRN_SRR0,r11
618	rfid
619
620
621/*
622 * kexec_sequence(newstack, start, image, control, clear_all())
623 *
624 * does the grungy work with stack switching and real mode switches
625 * also does simple calls to other code
626 */
627
628_GLOBAL(kexec_sequence)
629	mflr	r0
630	std	r0,16(r1)
631
632	/* switch stacks to newstack -- &kexec_stack.stack */
633	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
634	mr	r1,r3
635
636	li	r0,0
637	std	r0,16(r1)
638
639	/* save regs for local vars on new stack.
640	 * yes, we won't go back, but ...
641	 */
642	std	r31,-8(r1)
643	std	r30,-16(r1)
644	std	r29,-24(r1)
645	std	r28,-32(r1)
646	std	r27,-40(r1)
647	std	r26,-48(r1)
648	std	r25,-56(r1)
649
650	stdu	r1,-STACK_FRAME_OVERHEAD-64(r1)
651
652	/* save args into preserved regs */
653	mr	r31,r3			/* newstack (both) */
654	mr	r30,r4			/* start (real) */
655	mr	r29,r5			/* image (virt) */
656	mr	r28,r6			/* control, unused */
657	mr	r27,r7			/* clear_all() fn desc */
658	mr	r26,r8			/* spare */
659	lhz	r25,PACAHWCPUID(r13)	/* get our phys cpu from paca */
660
661	/* disable interrupts, we are overwriting kernel data next */
662	mfmsr	r3
663	rlwinm	r3,r3,0,17,15
664	mtmsrd	r3,1
665
666	/* copy dest pages, flush whole dest image */
667	mr	r3,r29
668	bl	.kexec_copy_flush	/* (image) */
669
670	/* turn off mmu */
671	bl	real_mode
672
673	/* copy  0x100 bytes starting at start to 0 */
674	li	r3,0
675	mr	r4,r30		/* start, aka phys mem offset */
676	li	r5,0x100
677	li	r6,0
678	bl	.copy_and_flush	/* (dest, src, copy limit, start offset) */
6791:	/* assume normal blr return */
680
681	/* release other cpus to the new kernel secondary start at 0x60 */
682	mflr	r5
683	li	r6,1
684	stw	r6,kexec_flag-1b(5)
685
686	/* clear out hardware hash page table and tlb */
687	ld	r5,0(r27)		/* deref function descriptor */
688	mtctr	r5
689	bctrl				/* ppc_md.hpte_clear_all(void); */
690
691/*
692 *   kexec image calling is:
693 *      the first 0x100 bytes of the entry point are copied to 0
694 *
695 *      all slaves branch to slave = 0x60 (absolute)
696 *              slave(phys_cpu_id);
697 *
698 *      master goes to start = entry point
699 *              start(phys_cpu_id, start, 0);
700 *
701 *
702 *   a wrapper is needed to call existing kernels, here is an approximate
703 *   description of one method:
704 *
705 * v2: (2.6.10)
706 *   start will be near the boot_block (maybe 0x100 bytes before it?)
707 *   it will have a 0x60, which will b to boot_block, where it will wait
708 *   and 0 will store phys into struct boot-block and load r3 from there,
709 *   copy kernel 0-0x100 and tell slaves to back down to 0x60 again
710 *
711 * v1: (2.6.9)
712 *    boot block will have all cpus scanning device tree to see if they
713 *    are the boot cpu ?????
714 *    other device tree differences (prop sizes, va vs pa, etc)...
715 */
716	mr	r3,r25	# my phys cpu
717	mr	r4,r30	# start, aka phys mem offset
718	mtlr	4
719	li	r5,0
720	blr	/* image->start(physid, image->start, 0); */
721#endif /* CONFIG_KEXEC */
722