xref: /linux/arch/arm/kernel/head.S (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
1/*
2 *  linux/arch/arm/kernel/head.S
3 *
4 *  Copyright (C) 1994-2002 Russell King
5 *  Copyright (c) 2003 ARM Limited
6 *  All Rights Reserved
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 *  Kernel startup code for all 32-bit CPUs
13 */
14#include <linux/linkage.h>
15#include <linux/init.h>
16
17#include <asm/assembler.h>
18#include <asm/cp15.h>
19#include <asm/domain.h>
20#include <asm/ptrace.h>
21#include <asm/asm-offsets.h>
22#include <asm/memory.h>
23#include <asm/thread_info.h>
24#include <asm/pgtable.h>
25
26#if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_SEMIHOSTING)
27#include CONFIG_DEBUG_LL_INCLUDE
28#endif
29
30/*
31 * swapper_pg_dir is the virtual address of the initial page table.
32 * We place the page tables 16K below KERNEL_RAM_VADDR.  Therefore, we must
33 * make sure that KERNEL_RAM_VADDR is correctly set.  Currently, we expect
34 * the least significant 16 bits to be 0x8000, but we could probably
35 * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000.
36 */
37#define KERNEL_RAM_VADDR	(PAGE_OFFSET + TEXT_OFFSET)
38#if (KERNEL_RAM_VADDR & 0xffff) != 0x8000
39#error KERNEL_RAM_VADDR must start at 0xXXXX8000
40#endif
41
42#ifdef CONFIG_ARM_LPAE
43	/* LPAE requires an additional page for the PGD */
44#define PG_DIR_SIZE	0x5000
45#define PMD_ORDER	3
46#else
47#define PG_DIR_SIZE	0x4000
48#define PMD_ORDER	2
49#endif
50
51	.globl	swapper_pg_dir
52	.equ	swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE
53
54	.macro	pgtbl, rd, phys
55	add	\rd, \phys, #TEXT_OFFSET
56	sub	\rd, \rd, #PG_DIR_SIZE
57	.endm
58
59/*
60 * Kernel startup entry point.
61 * ---------------------------
62 *
63 * This is normally called from the decompressor code.  The requirements
64 * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
65 * r1 = machine nr, r2 = atags or dtb pointer.
66 *
67 * This code is mostly position independent, so if you link the kernel at
68 * 0xc0008000, you call this at __pa(0xc0008000).
69 *
70 * See linux/arch/arm/tools/mach-types for the complete list of machine
71 * numbers for r1.
72 *
73 * We're trying to keep crap to a minimum; DO NOT add any machine specific
74 * crap here - that's what the boot loader (or in extreme, well justified
75 * circumstances, zImage) is for.
76 */
77	.arm
78
79	__HEAD
80ENTRY(stext)
81 ARM_BE8(setend	be )			@ ensure we are in BE8 mode
82
83 THUMB(	adr	r9, BSYM(1f)	)	@ Kernel is always entered in ARM.
84 THUMB(	bx	r9		)	@ If this is a Thumb-2 kernel,
85 THUMB(	.thumb			)	@ switch to Thumb now.
86 THUMB(1:			)
87
88#ifdef CONFIG_ARM_VIRT_EXT
89	bl	__hyp_stub_install
90#endif
91	@ ensure svc mode and all interrupts masked
92	safe_svcmode_maskall r9
93
94	mrc	p15, 0, r9, c0, c0		@ get processor id
95	bl	__lookup_processor_type		@ r5=procinfo r9=cpuid
96	movs	r10, r5				@ invalid processor (r5=0)?
97 THUMB( it	eq )		@ force fixup-able long branch encoding
98	beq	__error_p			@ yes, error 'p'
99
100#ifdef CONFIG_ARM_LPAE
101	mrc	p15, 0, r3, c0, c1, 4		@ read ID_MMFR0
102	and	r3, r3, #0xf			@ extract VMSA support
103	cmp	r3, #5				@ long-descriptor translation table format?
104 THUMB( it	lo )				@ force fixup-able long branch encoding
105	blo	__error_lpae			@ only classic page table format
106#endif
107
108#ifndef CONFIG_XIP_KERNEL
109	adr	r3, 2f
110	ldmia	r3, {r4, r8}
111	sub	r4, r3, r4			@ (PHYS_OFFSET - PAGE_OFFSET)
112	add	r8, r8, r4			@ PHYS_OFFSET
113#else
114	ldr	r8, =PLAT_PHYS_OFFSET		@ always constant in this case
115#endif
116
117	/*
118	 * r1 = machine no, r2 = atags or dtb,
119	 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
120	 */
121	bl	__vet_atags
122#ifdef CONFIG_SMP_ON_UP
123	bl	__fixup_smp
124#endif
125#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
126	bl	__fixup_pv_table
127#endif
128	bl	__create_page_tables
129
130	/*
131	 * The following calls CPU specific code in a position independent
132	 * manner.  See arch/arm/mm/proc-*.S for details.  r10 = base of
133	 * xxx_proc_info structure selected by __lookup_processor_type
134	 * above.  On return, the CPU will be ready for the MMU to be
135	 * turned on, and r0 will hold the CPU control register value.
136	 */
137	ldr	r13, =__mmap_switched		@ address to jump to after
138						@ mmu has been enabled
139	adr	lr, BSYM(1f)			@ return (PIC) address
140	mov	r8, r4				@ set TTBR1 to swapper_pg_dir
141	ldr	r12, [r10, #PROCINFO_INITFUNC]
142	add	r12, r12, r10
143	ret	r12
1441:	b	__enable_mmu
145ENDPROC(stext)
146	.ltorg
147#ifndef CONFIG_XIP_KERNEL
1482:	.long	.
149	.long	PAGE_OFFSET
150#endif
151
152/*
153 * Setup the initial page tables.  We only setup the barest
154 * amount which are required to get the kernel running, which
155 * generally means mapping in the kernel code.
156 *
157 * r8 = phys_offset, r9 = cpuid, r10 = procinfo
158 *
159 * Returns:
160 *  r0, r3, r5-r7 corrupted
161 *  r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h)
162 */
163__create_page_tables:
164	pgtbl	r4, r8				@ page table address
165
166	/*
167	 * Clear the swapper page table
168	 */
169	mov	r0, r4
170	mov	r3, #0
171	add	r6, r0, #PG_DIR_SIZE
1721:	str	r3, [r0], #4
173	str	r3, [r0], #4
174	str	r3, [r0], #4
175	str	r3, [r0], #4
176	teq	r0, r6
177	bne	1b
178
179#ifdef CONFIG_ARM_LPAE
180	/*
181	 * Build the PGD table (first level) to point to the PMD table. A PGD
182	 * entry is 64-bit wide.
183	 */
184	mov	r0, r4
185	add	r3, r4, #0x1000			@ first PMD table address
186	orr	r3, r3, #3			@ PGD block type
187	mov	r6, #4				@ PTRS_PER_PGD
188	mov	r7, #1 << (55 - 32)		@ L_PGD_SWAPPER
1891:
190#ifdef CONFIG_CPU_ENDIAN_BE8
191	str	r7, [r0], #4			@ set top PGD entry bits
192	str	r3, [r0], #4			@ set bottom PGD entry bits
193#else
194	str	r3, [r0], #4			@ set bottom PGD entry bits
195	str	r7, [r0], #4			@ set top PGD entry bits
196#endif
197	add	r3, r3, #0x1000			@ next PMD table
198	subs	r6, r6, #1
199	bne	1b
200
201	add	r4, r4, #0x1000			@ point to the PMD tables
202#ifdef CONFIG_CPU_ENDIAN_BE8
203	add	r4, r4, #4			@ we only write the bottom word
204#endif
205#endif
206
207	ldr	r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags
208
209	/*
210	 * Create identity mapping to cater for __enable_mmu.
211	 * This identity mapping will be removed by paging_init().
212	 */
213	adr	r0, __turn_mmu_on_loc
214	ldmia	r0, {r3, r5, r6}
215	sub	r0, r0, r3			@ virt->phys offset
216	add	r5, r5, r0			@ phys __turn_mmu_on
217	add	r6, r6, r0			@ phys __turn_mmu_on_end
218	mov	r5, r5, lsr #SECTION_SHIFT
219	mov	r6, r6, lsr #SECTION_SHIFT
220
2211:	orr	r3, r7, r5, lsl #SECTION_SHIFT	@ flags + kernel base
222	str	r3, [r4, r5, lsl #PMD_ORDER]	@ identity mapping
223	cmp	r5, r6
224	addlo	r5, r5, #1			@ next section
225	blo	1b
226
227	/*
228	 * Map our RAM from the start to the end of the kernel .bss section.
229	 */
230	add	r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER)
231	ldr	r6, =(_end - 1)
232	orr	r3, r8, r7
233	add	r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
2341:	str	r3, [r0], #1 << PMD_ORDER
235	add	r3, r3, #1 << SECTION_SHIFT
236	cmp	r0, r6
237	bls	1b
238
239#ifdef CONFIG_XIP_KERNEL
240	/*
241	 * Map the kernel image separately as it is not located in RAM.
242	 */
243#define XIP_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
244	mov	r3, pc
245	mov	r3, r3, lsr #SECTION_SHIFT
246	orr	r3, r7, r3, lsl #SECTION_SHIFT
247	add	r0, r4,  #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER)
248	str	r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]!
249	ldr	r6, =(_edata_loc - 1)
250	add	r0, r0, #1 << PMD_ORDER
251	add	r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
2521:	cmp	r0, r6
253	add	r3, r3, #1 << SECTION_SHIFT
254	strls	r3, [r0], #1 << PMD_ORDER
255	bls	1b
256#endif
257
258	/*
259	 * Then map boot params address in r2 if specified.
260	 * We map 2 sections in case the ATAGs/DTB crosses a section boundary.
261	 */
262	mov	r0, r2, lsr #SECTION_SHIFT
263	movs	r0, r0, lsl #SECTION_SHIFT
264	subne	r3, r0, r8
265	addne	r3, r3, #PAGE_OFFSET
266	addne	r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER)
267	orrne	r6, r7, r0
268	strne	r6, [r3], #1 << PMD_ORDER
269	addne	r6, r6, #1 << SECTION_SHIFT
270	strne	r6, [r3]
271
272#if defined(CONFIG_ARM_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8)
273	sub	r4, r4, #4			@ Fixup page table pointer
274						@ for 64-bit descriptors
275#endif
276
277#ifdef CONFIG_DEBUG_LL
278#if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING)
279	/*
280	 * Map in IO space for serial debugging.
281	 * This allows debug messages to be output
282	 * via a serial console before paging_init.
283	 */
284	addruart r7, r3, r0
285
286	mov	r3, r3, lsr #SECTION_SHIFT
287	mov	r3, r3, lsl #PMD_ORDER
288
289	add	r0, r4, r3
290	mov	r3, r7, lsr #SECTION_SHIFT
291	ldr	r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
292	orr	r3, r7, r3, lsl #SECTION_SHIFT
293#ifdef CONFIG_ARM_LPAE
294	mov	r7, #1 << (54 - 32)		@ XN
295#ifdef CONFIG_CPU_ENDIAN_BE8
296	str	r7, [r0], #4
297	str	r3, [r0], #4
298#else
299	str	r3, [r0], #4
300	str	r7, [r0], #4
301#endif
302#else
303	orr	r3, r3, #PMD_SECT_XN
304	str	r3, [r0], #4
305#endif
306
307#else /* CONFIG_DEBUG_ICEDCC || CONFIG_DEBUG_SEMIHOSTING */
308	/* we don't need any serial debugging mappings */
309	ldr	r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
310#endif
311
312#if defined(CONFIG_ARCH_NETWINDER) || defined(CONFIG_ARCH_CATS)
313	/*
314	 * If we're using the NetWinder or CATS, we also need to map
315	 * in the 16550-type serial port for the debug messages
316	 */
317	add	r0, r4, #0xff000000 >> (SECTION_SHIFT - PMD_ORDER)
318	orr	r3, r7, #0x7c000000
319	str	r3, [r0]
320#endif
321#ifdef CONFIG_ARCH_RPC
322	/*
323	 * Map in screen at 0x02000000 & SCREEN2_BASE
324	 * Similar reasons here - for debug.  This is
325	 * only for Acorn RiscPC architectures.
326	 */
327	add	r0, r4, #0x02000000 >> (SECTION_SHIFT - PMD_ORDER)
328	orr	r3, r7, #0x02000000
329	str	r3, [r0]
330	add	r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER)
331	str	r3, [r0]
332#endif
333#endif
334#ifdef CONFIG_ARM_LPAE
335	sub	r4, r4, #0x1000		@ point to the PGD table
336	mov	r4, r4, lsr #ARCH_PGD_SHIFT
337#endif
338	ret	lr
339ENDPROC(__create_page_tables)
340	.ltorg
341	.align
342__turn_mmu_on_loc:
343	.long	.
344	.long	__turn_mmu_on
345	.long	__turn_mmu_on_end
346
347#if defined(CONFIG_SMP)
348	.text
349ENTRY(secondary_startup_arm)
350	.arm
351 THUMB(	adr	r9, BSYM(1f)	)	@ Kernel is entered in ARM.
352 THUMB(	bx	r9		)	@ If this is a Thumb-2 kernel,
353 THUMB(	.thumb			)	@ switch to Thumb now.
354 THUMB(1:			)
355ENTRY(secondary_startup)
356	/*
357	 * Common entry point for secondary CPUs.
358	 *
359	 * Ensure that we're in SVC mode, and IRQs are disabled.  Lookup
360	 * the processor type - there is no need to check the machine type
361	 * as it has already been validated by the primary processor.
362	 */
363
364 ARM_BE8(setend	be)				@ ensure we are in BE8 mode
365
366#ifdef CONFIG_ARM_VIRT_EXT
367	bl	__hyp_stub_install_secondary
368#endif
369	safe_svcmode_maskall r9
370
371	mrc	p15, 0, r9, c0, c0		@ get processor id
372	bl	__lookup_processor_type
373	movs	r10, r5				@ invalid processor?
374	moveq	r0, #'p'			@ yes, error 'p'
375 THUMB( it	eq )		@ force fixup-able long branch encoding
376	beq	__error_p
377
378	/*
379	 * Use the page tables supplied from  __cpu_up.
380	 */
381	adr	r4, __secondary_data
382	ldmia	r4, {r5, r7, r12}		@ address to jump to after
383	sub	lr, r4, r5			@ mmu has been enabled
384	ldr	r4, [r7, lr]			@ get secondary_data.pgdir
385	add	r7, r7, #4
386	ldr	r8, [r7, lr]			@ get secondary_data.swapper_pg_dir
387	adr	lr, BSYM(__enable_mmu)		@ return address
388	mov	r13, r12			@ __secondary_switched address
389	ldr	r12, [r10, #PROCINFO_INITFUNC]
390	add	r12, r12, r10			@ initialise processor
391						@ (return control reg)
392	ret	r12
393ENDPROC(secondary_startup)
394ENDPROC(secondary_startup_arm)
395
396	/*
397	 * r6  = &secondary_data
398	 */
399ENTRY(__secondary_switched)
400	ldr	sp, [r7, #4]			@ get secondary_data.stack
401	mov	fp, #0
402	b	secondary_start_kernel
403ENDPROC(__secondary_switched)
404
405	.align
406
407	.type	__secondary_data, %object
408__secondary_data:
409	.long	.
410	.long	secondary_data
411	.long	__secondary_switched
412#endif /* defined(CONFIG_SMP) */
413
414
415
416/*
417 * Setup common bits before finally enabling the MMU.  Essentially
418 * this is just loading the page table pointer and domain access
419 * registers.
420 *
421 *  r0  = cp#15 control register
422 *  r1  = machine ID
423 *  r2  = atags or dtb pointer
424 *  r4  = page table (see ARCH_PGD_SHIFT in asm/memory.h)
425 *  r9  = processor ID
426 *  r13 = *virtual* address to jump to upon completion
427 */
428__enable_mmu:
429#if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6
430	orr	r0, r0, #CR_A
431#else
432	bic	r0, r0, #CR_A
433#endif
434#ifdef CONFIG_CPU_DCACHE_DISABLE
435	bic	r0, r0, #CR_C
436#endif
437#ifdef CONFIG_CPU_BPREDICT_DISABLE
438	bic	r0, r0, #CR_Z
439#endif
440#ifdef CONFIG_CPU_ICACHE_DISABLE
441	bic	r0, r0, #CR_I
442#endif
443#ifndef CONFIG_ARM_LPAE
444	mov	r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
445		      domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
446		      domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
447		      domain_val(DOMAIN_IO, DOMAIN_CLIENT))
448	mcr	p15, 0, r5, c3, c0, 0		@ load domain access register
449	mcr	p15, 0, r4, c2, c0, 0		@ load page table pointer
450#endif
451	b	__turn_mmu_on
452ENDPROC(__enable_mmu)
453
454/*
455 * Enable the MMU.  This completely changes the structure of the visible
456 * memory space.  You will not be able to trace execution through this.
457 * If you have an enquiry about this, *please* check the linux-arm-kernel
458 * mailing list archives BEFORE sending another post to the list.
459 *
460 *  r0  = cp#15 control register
461 *  r1  = machine ID
462 *  r2  = atags or dtb pointer
463 *  r9  = processor ID
464 *  r13 = *virtual* address to jump to upon completion
465 *
466 * other registers depend on the function called upon completion
467 */
468	.align	5
469	.pushsection	.idmap.text, "ax"
470ENTRY(__turn_mmu_on)
471	mov	r0, r0
472	instr_sync
473	mcr	p15, 0, r0, c1, c0, 0		@ write control reg
474	mrc	p15, 0, r3, c0, c0, 0		@ read id reg
475	instr_sync
476	mov	r3, r3
477	mov	r3, r13
478	ret	r3
479__turn_mmu_on_end:
480ENDPROC(__turn_mmu_on)
481	.popsection
482
483
484#ifdef CONFIG_SMP_ON_UP
485	__HEAD
486__fixup_smp:
487	and	r3, r9, #0x000f0000	@ architecture version
488	teq	r3, #0x000f0000		@ CPU ID supported?
489	bne	__fixup_smp_on_up	@ no, assume UP
490
491	bic	r3, r9, #0x00ff0000
492	bic	r3, r3, #0x0000000f	@ mask 0xff00fff0
493	mov	r4, #0x41000000
494	orr	r4, r4, #0x0000b000
495	orr	r4, r4, #0x00000020	@ val 0x4100b020
496	teq	r3, r4			@ ARM 11MPCore?
497	reteq	lr			@ yes, assume SMP
498
499	mrc	p15, 0, r0, c0, c0, 5	@ read MPIDR
500	and	r0, r0, #0xc0000000	@ multiprocessing extensions and
501	teq	r0, #0x80000000		@ not part of a uniprocessor system?
502	bne    __fixup_smp_on_up	@ no, assume UP
503
504	@ Core indicates it is SMP. Check for Aegis SOC where a single
505	@ Cortex-A9 CPU is present but SMP operations fault.
506	mov	r4, #0x41000000
507	orr	r4, r4, #0x0000c000
508	orr	r4, r4, #0x00000090
509	teq	r3, r4			@ Check for ARM Cortex-A9
510	retne	lr			@ Not ARM Cortex-A9,
511
512	@ If a future SoC *does* use 0x0 as the PERIPH_BASE, then the
513	@ below address check will need to be #ifdef'd or equivalent
514	@ for the Aegis platform.
515	mrc	p15, 4, r0, c15, c0	@ get SCU base address
516	teq	r0, #0x0		@ '0' on actual UP A9 hardware
517	beq	__fixup_smp_on_up	@ So its an A9 UP
518	ldr	r0, [r0, #4]		@ read SCU Config
519ARM_BE8(rev	r0, r0)			@ byteswap if big endian
520	and	r0, r0, #0x3		@ number of CPUs
521	teq	r0, #0x0		@ is 1?
522	retne	lr
523
524__fixup_smp_on_up:
525	adr	r0, 1f
526	ldmia	r0, {r3 - r5}
527	sub	r3, r0, r3
528	add	r4, r4, r3
529	add	r5, r5, r3
530	b	__do_fixup_smp_on_up
531ENDPROC(__fixup_smp)
532
533	.align
5341:	.word	.
535	.word	__smpalt_begin
536	.word	__smpalt_end
537
538	.pushsection .data
539	.globl	smp_on_up
540smp_on_up:
541	ALT_SMP(.long	1)
542	ALT_UP(.long	0)
543	.popsection
544#endif
545
546	.text
547__do_fixup_smp_on_up:
548	cmp	r4, r5
549	reths	lr
550	ldmia	r4!, {r0, r6}
551 ARM(	str	r6, [r0, r3]	)
552 THUMB(	add	r0, r0, r3	)
553#ifdef __ARMEB__
554 THUMB(	mov	r6, r6, ror #16	)	@ Convert word order for big-endian.
555#endif
556 THUMB(	strh	r6, [r0], #2	)	@ For Thumb-2, store as two halfwords
557 THUMB(	mov	r6, r6, lsr #16	)	@ to be robust against misaligned r3.
558 THUMB(	strh	r6, [r0]	)
559	b	__do_fixup_smp_on_up
560ENDPROC(__do_fixup_smp_on_up)
561
562ENTRY(fixup_smp)
563	stmfd	sp!, {r4 - r6, lr}
564	mov	r4, r0
565	add	r5, r0, r1
566	mov	r3, #0
567	bl	__do_fixup_smp_on_up
568	ldmfd	sp!, {r4 - r6, pc}
569ENDPROC(fixup_smp)
570
571#ifdef __ARMEB__
572#define LOW_OFFSET	0x4
573#define HIGH_OFFSET	0x0
574#else
575#define LOW_OFFSET	0x0
576#define HIGH_OFFSET	0x4
577#endif
578
579#ifdef CONFIG_ARM_PATCH_PHYS_VIRT
580
581/* __fixup_pv_table - patch the stub instructions with the delta between
582 * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and
583 * can be expressed by an immediate shifter operand. The stub instruction
584 * has a form of '(add|sub) rd, rn, #imm'.
585 */
586	__HEAD
587__fixup_pv_table:
588	adr	r0, 1f
589	ldmia	r0, {r3-r7}
590	mvn	ip, #0
591	subs	r3, r0, r3	@ PHYS_OFFSET - PAGE_OFFSET
592	add	r4, r4, r3	@ adjust table start address
593	add	r5, r5, r3	@ adjust table end address
594	add	r6, r6, r3	@ adjust __pv_phys_pfn_offset address
595	add	r7, r7, r3	@ adjust __pv_offset address
596	mov	r0, r8, lsr #PAGE_SHIFT	@ convert to PFN
597	str	r0, [r6]	@ save computed PHYS_OFFSET to __pv_phys_pfn_offset
598	strcc	ip, [r7, #HIGH_OFFSET]	@ save to __pv_offset high bits
599	mov	r6, r3, lsr #24	@ constant for add/sub instructions
600	teq	r3, r6, lsl #24 @ must be 16MiB aligned
601THUMB(	it	ne		@ cross section branch )
602	bne	__error
603	str	r3, [r7, #LOW_OFFSET]	@ save to __pv_offset low bits
604	b	__fixup_a_pv_table
605ENDPROC(__fixup_pv_table)
606
607	.align
6081:	.long	.
609	.long	__pv_table_begin
610	.long	__pv_table_end
6112:	.long	__pv_phys_pfn_offset
612	.long	__pv_offset
613
614	.text
615__fixup_a_pv_table:
616	adr	r0, 3f
617	ldr	r6, [r0]
618	add	r6, r6, r3
619	ldr	r0, [r6, #HIGH_OFFSET]	@ pv_offset high word
620	ldr	r6, [r6, #LOW_OFFSET]	@ pv_offset low word
621	mov	r6, r6, lsr #24
622	cmn	r0, #1
623#ifdef CONFIG_THUMB2_KERNEL
624	moveq	r0, #0x200000	@ set bit 21, mov to mvn instruction
625	lsls	r6, #24
626	beq	2f
627	clz	r7, r6
628	lsr	r6, #24
629	lsl	r6, r7
630	bic	r6, #0x0080
631	lsrs	r7, #1
632	orrcs	r6, #0x0080
633	orr	r6, r6, r7, lsl #12
634	orr	r6, #0x4000
635	b	2f
6361:	add     r7, r3
637	ldrh	ip, [r7, #2]
638ARM_BE8(rev16	ip, ip)
639	tst	ip, #0x4000
640	and	ip, #0x8f00
641	orrne	ip, r6	@ mask in offset bits 31-24
642	orreq	ip, r0	@ mask in offset bits 7-0
643ARM_BE8(rev16	ip, ip)
644	strh	ip, [r7, #2]
645	bne	2f
646	ldrh	ip, [r7]
647ARM_BE8(rev16	ip, ip)
648	bic	ip, #0x20
649	orr	ip, ip, r0, lsr #16
650ARM_BE8(rev16	ip, ip)
651	strh	ip, [r7]
6522:	cmp	r4, r5
653	ldrcc	r7, [r4], #4	@ use branch for delay slot
654	bcc	1b
655	bx	lr
656#else
657#ifdef CONFIG_CPU_ENDIAN_BE8
658	moveq	r0, #0x00004000	@ set bit 22, mov to mvn instruction
659#else
660	moveq	r0, #0x400000	@ set bit 22, mov to mvn instruction
661#endif
662	b	2f
6631:	ldr	ip, [r7, r3]
664#ifdef CONFIG_CPU_ENDIAN_BE8
665	@ in BE8, we load data in BE, but instructions still in LE
666	bic	ip, ip, #0xff000000
667	tst	ip, #0x000f0000	@ check the rotation field
668	orrne	ip, ip, r6, lsl #24 @ mask in offset bits 31-24
669	biceq	ip, ip, #0x00004000 @ clear bit 22
670	orreq	ip, ip, r0      @ mask in offset bits 7-0
671#else
672	bic	ip, ip, #0x000000ff
673	tst	ip, #0xf00	@ check the rotation field
674	orrne	ip, ip, r6	@ mask in offset bits 31-24
675	biceq	ip, ip, #0x400000	@ clear bit 22
676	orreq	ip, ip, r0	@ mask in offset bits 7-0
677#endif
678	str	ip, [r7, r3]
6792:	cmp	r4, r5
680	ldrcc	r7, [r4], #4	@ use branch for delay slot
681	bcc	1b
682	ret	lr
683#endif
684ENDPROC(__fixup_a_pv_table)
685
686	.align
6873:	.long __pv_offset
688
689ENTRY(fixup_pv_table)
690	stmfd	sp!, {r4 - r7, lr}
691	mov	r3, #0			@ no offset
692	mov	r4, r0			@ r0 = table start
693	add	r5, r0, r1		@ r1 = table size
694	bl	__fixup_a_pv_table
695	ldmfd	sp!, {r4 - r7, pc}
696ENDPROC(fixup_pv_table)
697
698	.data
699	.globl	__pv_phys_pfn_offset
700	.type	__pv_phys_pfn_offset, %object
701__pv_phys_pfn_offset:
702	.word	0
703	.size	__pv_phys_pfn_offset, . -__pv_phys_pfn_offset
704
705	.globl	__pv_offset
706	.type	__pv_offset, %object
707__pv_offset:
708	.quad	0
709	.size	__pv_offset, . -__pv_offset
710#endif
711
712#include "head-common.S"
713