[deliverable/linux.git] / arch / x86 / kernel / relocate_kernel_32.S

/*
 * relocate_kernel.S - put the kernel image in place to boot
 * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */

#include <linux/linkage.h>
#include <asm/page.h>
#include <asm/kexec.h>
#include <asm/processor-flags.h>

/*
 * Must be relocatable PIC code callable as a C function
 */

#define PTR(x) (x << 2)

/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE
 * ~ control_page + PAGE_SIZE are used as data storage and stack for
 * jumping back
 */
#define DATA(offset)		(KEXEC_CONTROL_CODE_MAX_SIZE+(offset))

/* Minimal CPU state */
#define ESP			DATA(0x0)
#define CR0			DATA(0x4)
#define CR3			DATA(0x8)
#define CR4			DATA(0xc)

/* other data */
#define CP_VA_CONTROL_PAGE	DATA(0x10)
#define CP_PA_PGD		DATA(0x14)
#define CP_PA_SWAP_PAGE		DATA(0x18)
#define CP_PA_BACKUP_PAGES_MAP	DATA(0x1c)

	.text
	.globl relocate_kernel
relocate_kernel:
	/* Save the CPU context, used for jumping back */

	pushl	%ebx
	pushl	%esi
	pushl	%edi
	pushl	%ebp
	pushf

	movl	20+8(%esp), %ebp /* list of pages */
	movl	PTR(VA_CONTROL_PAGE)(%ebp), %edi
	movl	%esp, ESP(%edi)
	movl	%cr0, %eax
	movl	%eax, CR0(%edi)
	movl	%cr3, %eax
	movl	%eax, CR3(%edi)
	movl	%cr4, %eax
	movl	%eax, CR4(%edi)

	/* read the arguments and say goodbye to the stack */
	movl  20+4(%esp), %ebx /* page_list */
	movl  20+8(%esp), %ebp /* list of pages */
	movl  20+12(%esp), %edx /* start address */
	movl  20+16(%esp), %ecx /* cpu_has_pae */
	movl  20+20(%esp), %esi /* preserve_context */

	/* zero out flags, and disable interrupts */
	pushl $0
	popfl

	/* save some information for jumping back */
	movl	PTR(VA_CONTROL_PAGE)(%ebp), %edi
	movl	%edi, CP_VA_CONTROL_PAGE(%edi)
	movl	PTR(PA_PGD)(%ebp), %eax
	movl	%eax, CP_PA_PGD(%edi)
	movl	PTR(PA_SWAP_PAGE)(%ebp), %eax
	movl	%eax, CP_PA_SWAP_PAGE(%edi)
	movl	%ebx, CP_PA_BACKUP_PAGES_MAP(%edi)

	/* get physical address of control page now */
	/* this is impossible after page table switch */
	movl	PTR(PA_CONTROL_PAGE)(%ebp), %edi

	/* switch to new set of page tables */
	movl	PTR(PA_PGD)(%ebp), %eax
	movl	%eax, %cr3

	/* setup a new stack at the end of the physical control page */
	lea	PAGE_SIZE(%edi), %esp

	/* jump to identity mapped page */
	movl    %edi, %eax
	addl    $(identity_mapped - relocate_kernel), %eax
	pushl   %eax
	ret

identity_mapped:
	/* store the start address on the stack */
	pushl   %edx

	/* Set cr0 to a known state:
	 *  - Paging disabled
	 *  - Alignment check disabled
	 *  - Write protect disabled
	 *  - No task switch
	 *  - Don't do FP software emulation.
	 *  - Proctected mode enabled
	 */
	movl	%cr0, %eax
	andl	$~(X86_CR0_PG | X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %eax
	orl	$(X86_CR0_PE), %eax
	movl	%eax, %cr0

	/* clear cr4 if applicable */
	testl	%ecx, %ecx
	jz	1f
	/* Set cr4 to a known state:
	 * Setting everything to zero seems safe.
	 */
	xorl	%eax, %eax
	movl	%eax, %cr4

	jmp 1f
1:

	/* Flush the TLB (needed?) */
	xorl	%eax, %eax
	movl	%eax, %cr3

	movl	CP_PA_SWAP_PAGE(%edi), %eax
	pushl	%eax
	pushl	%ebx
	call	swap_pages
	addl	$8, %esp

	/* To be certain of avoiding problems with self-modifying code
	 * I need to execute a serializing instruction here.
	 * So I flush the TLB, it's handy, and not processor dependent.
	 */
	xorl	%eax, %eax
	movl	%eax, %cr3

	/* set all of the registers to known values */
	/* leave %esp alone */

	testl	%esi, %esi
	jnz 1f
	xorl	%edi, %edi
	xorl	%eax, %eax
	xorl	%ebx, %ebx
	xorl    %ecx, %ecx
	xorl    %edx, %edx
	xorl    %esi, %esi
	xorl    %ebp, %ebp
	ret
1:
	popl	%edx
	movl	CP_PA_SWAP_PAGE(%edi), %esp
	addl	$PAGE_SIZE, %esp
2:
	call	*%edx

	/* get the re-entry point of the peer system */
	movl	0(%esp), %ebp
	call	1f
1:
	popl	%ebx
	subl	$(1b - relocate_kernel), %ebx
	movl	CP_VA_CONTROL_PAGE(%ebx), %edi
	lea	PAGE_SIZE(%ebx), %esp
	movl	CP_PA_SWAP_PAGE(%ebx), %eax
	movl	CP_PA_BACKUP_PAGES_MAP(%ebx), %edx
	pushl	%eax
	pushl	%edx
	call	swap_pages
	addl	$8, %esp
	movl	CP_PA_PGD(%ebx), %eax
	movl	%eax, %cr3
	movl	%cr0, %eax
	orl	$(1<<31), %eax
	movl	%eax, %cr0
	lea	PAGE_SIZE(%edi), %esp
	movl	%edi, %eax
	addl	$(virtual_mapped - relocate_kernel), %eax
	pushl	%eax
	ret

virtual_mapped:
	movl	CR4(%edi), %eax
	movl	%eax, %cr4
	movl	CR3(%edi), %eax
	movl	%eax, %cr3
	movl	CR0(%edi), %eax
	movl	%eax, %cr0
	movl	ESP(%edi), %esp
	movl	%ebp, %eax

	popf
	popl	%ebp
	popl	%edi
	popl	%esi
	popl	%ebx
	ret

	/* Do the copies */
swap_pages:
	movl	8(%esp), %edx
	movl	4(%esp), %ecx
	pushl	%ebp
	pushl	%ebx
	pushl	%edi
	pushl	%esi
	movl	%ecx, %ebx
	jmp	1f

0:	/* top, read another word from the indirection page */
	movl	(%ebx), %ecx
	addl	$4, %ebx
1:
	testl	$0x1,   %ecx  /* is it a destination page */
	jz	2f
	movl	%ecx,	%edi
	andl	$0xfffff000, %edi
	jmp     0b
2:
	testl	$0x2,	%ecx  /* is it an indirection page */
	jz	2f
	movl	%ecx,	%ebx
	andl	$0xfffff000, %ebx
	jmp     0b
2:
	testl   $0x4,   %ecx /* is it the done indicator */
	jz      2f
	jmp     3f
2:
	testl   $0x8,   %ecx /* is it the source indicator */
	jz      0b	     /* Ignore it otherwise */
	movl    %ecx,   %esi /* For every source page do a copy */
	andl    $0xfffff000, %esi

	movl	%edi, %eax
	movl	%esi, %ebp

	movl	%edx, %edi
	movl    $1024, %ecx
	rep ; movsl

	movl	%ebp, %edi
	movl	%eax, %esi
	movl	$1024, %ecx
	rep ; movsl

	movl	%eax, %edi
	movl	%edx, %esi
	movl	$1024, %ecx
	rep ; movsl

	lea	PAGE_SIZE(%ebp), %esi
	jmp     0b
3:
	popl	%esi
	popl	%edi
	popl	%ebx
	popl	%ebp
	ret

	.globl kexec_control_code_size
.set kexec_control_code_size, . - relocate_kernel
Commit	Line	Data
5033cba0 EB	1	/*
	2	* relocate_kernel.S - put the kernel image in place to boot
	3	* Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
	4	*
	5	* This source code is licensed under the GNU General Public License,
	6	* Version 2. See the file COPYING for more details.
	7	*/
	8
	9	#include <linux/linkage.h>
3566561b MD	10	#include <asm/page.h>
3566561b MD	11	#include <asm/kexec.h>
fd3af531	12	#include <asm/processor-flags.h>
3566561b MD	13
	14	/*
	15	* Must be relocatable PIC code callable as a C function
	16	*/
	17
	18	#define PTR(x) (x << 2)
3566561b	19
fb45daa6 HY	20	/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE
	21	* ~ control_page + PAGE_SIZE are used as data storage and stack for
	22	* jumping back
3ab83521	23	*/
fb45daa6	24	#define DATA(offset) (KEXEC_CONTROL_CODE_MAX_SIZE+(offset))
3ab83521 HY	25
	26	/* Minimal CPU state */
	27	#define ESP DATA(0x0)
	28	#define CR0 DATA(0x4)
	29	#define CR3 DATA(0x8)
	30	#define CR4 DATA(0xc)
	31
	32	/* other data */
	33	#define CP_VA_CONTROL_PAGE DATA(0x10)
	34	#define CP_PA_PGD DATA(0x14)
	35	#define CP_PA_SWAP_PAGE DATA(0x18)
	36	#define CP_PA_BACKUP_PAGES_MAP DATA(0x1c)
	37
3566561b	38	.text
3566561b MD	39	.globl relocate_kernel
3566561b MD	40	relocate_kernel:
3ab83521 HY	41	/* Save the CPU context, used for jumping back */
	42
	43	pushl %ebx
	44	pushl %esi
	45	pushl %edi
	46	pushl %ebp
	47	pushf
	48
	49	movl 20+8(%esp), %ebp /* list of pages */
	50	movl PTR(VA_CONTROL_PAGE)(%ebp), %edi
	51	movl %esp, ESP(%edi)
	52	movl %cr0, %eax
	53	movl %eax, CR0(%edi)
	54	movl %cr3, %eax
	55	movl %eax, CR3(%edi)
	56	movl %cr4, %eax
	57	movl %eax, CR4(%edi)
3566561b	58
5033cba0	59	/* read the arguments and say goodbye to the stack */
3ab83521 HY	60	movl 20+4(%esp), %ebx /* page_list */
	61	movl 20+8(%esp), %ebp /* list of pages */
	62	movl 20+12(%esp), %edx /* start address */
	63	movl 20+16(%esp), %ecx /* cpu_has_pae */
	64	movl 20+20(%esp), %esi /* preserve_context */
5033cba0 EB	65
	66	/* zero out flags, and disable interrupts */
	67	pushl $0
	68	popfl
	69
3ab83521 HY	70	/* save some information for jumping back */
	71	movl PTR(VA_CONTROL_PAGE)(%ebp), %edi
	72	movl %edi, CP_VA_CONTROL_PAGE(%edi)
	73	movl PTR(PA_PGD)(%ebp), %eax
	74	movl %eax, CP_PA_PGD(%edi)
	75	movl PTR(PA_SWAP_PAGE)(%ebp), %eax
	76	movl %eax, CP_PA_SWAP_PAGE(%edi)
	77	movl %ebx, CP_PA_BACKUP_PAGES_MAP(%edi)
	78
3566561b MD	79	/* get physical address of control page now */
	80	/* this is impossible after page table switch */
	81	movl PTR(PA_CONTROL_PAGE)(%ebp), %edi
5033cba0	82
3566561b MD	83	/* switch to new set of page tables */
	84	movl PTR(PA_PGD)(%ebp), %eax
	85	movl %eax, %cr3
	86
	87	/* setup a new stack at the end of the physical control page */
a7bba17b	88	lea PAGE_SIZE(%edi), %esp
3566561b MD	89
	90	/* jump to identity mapped page */
	91	movl %edi, %eax
	92	addl $(identity_mapped - relocate_kernel), %eax
	93	pushl %eax
	94	ret
	95
	96	identity_mapped:
	97	/* store the start address on the stack */
	98	pushl %edx
5033cba0 EB	99
5033cba0 EB	100	/* Set cr0 to a known state:
fd3af531	101	* - Paging disabled
	102	* - Alignment check disabled
	103	* - Write protect disabled
	104	* - No task switch
	105	* - Don't do FP software emulation.
	106	* - Proctected mode enabled
5033cba0 EB	107	*/
5033cba0 EB	108	movl %cr0, %eax
fd3af531	109	andl $~(X86_CR0_PG \| X86_CR0_AM \| X86_CR0_WP \| X86_CR0_TS \| X86_CR0_EM), %eax
fd3af531	110	orl $(X86_CR0_PE), %eax
5033cba0 EB	111	movl %eax, %cr0
	112
	113	/* clear cr4 if applicable */
	114	testl %ecx, %ecx
	115	jz 1f
	116	/* Set cr4 to a known state:
	117	* Setting everything to zero seems safe.
	118	*/
4039ae53	119	xorl %eax, %eax
5033cba0 EB	120	movl %eax, %cr4
	121
	122	jmp 1f
	123	1:
	124
	125	/* Flush the TLB (needed?) */
	126	xorl %eax, %eax
	127	movl %eax, %cr3
	128
3ab83521 HY	129	movl CP_PA_SWAP_PAGE(%edi), %eax
	130	pushl %eax
	131	pushl %ebx
	132	call swap_pages
	133	addl $8, %esp
	134
	135	/* To be certain of avoiding problems with self-modifying code
	136	* I need to execute a serializing instruction here.
	137	* So I flush the TLB, it's handy, and not processor dependent.
	138	*/
	139	xorl %eax, %eax
	140	movl %eax, %cr3
	141
	142	/* set all of the registers to known values */
	143	/* leave %esp alone */
	144
	145	testl %esi, %esi
	146	jnz 1f
	147	xorl %edi, %edi
	148	xorl %eax, %eax
	149	xorl %ebx, %ebx
	150	xorl %ecx, %ecx
	151	xorl %edx, %edx
	152	xorl %esi, %esi
	153	xorl %ebp, %ebp
	154	ret
	155	1:
	156	popl %edx
	157	movl CP_PA_SWAP_PAGE(%edi), %esp
	158	addl $PAGE_SIZE, %esp
	159	2:
	160	call *%edx
	161
	162	/* get the re-entry point of the peer system */
	163	movl 0(%esp), %ebp
	164	call 1f
	165	1:
	166	popl %ebx
	167	subl $(1b - relocate_kernel), %ebx
	168	movl CP_VA_CONTROL_PAGE(%ebx), %edi
	169	lea PAGE_SIZE(%ebx), %esp
	170	movl CP_PA_SWAP_PAGE(%ebx), %eax
	171	movl CP_PA_BACKUP_PAGES_MAP(%ebx), %edx
	172	pushl %eax
	173	pushl %edx
	174	call swap_pages
	175	addl $8, %esp
	176	movl CP_PA_PGD(%ebx), %eax
	177	movl %eax, %cr3
	178	movl %cr0, %eax
	179	orl $(1<<31), %eax
	180	movl %eax, %cr0
	181	lea PAGE_SIZE(%edi), %esp
	182	movl %edi, %eax
	183	addl $(virtual_mapped - relocate_kernel), %eax
	184	pushl %eax
	185	ret
	186
	187	virtual_mapped:
	188	movl CR4(%edi), %eax
	189	movl %eax, %cr4
	190	movl CR3(%edi), %eax
	191	movl %eax, %cr3
	192	movl CR0(%edi), %eax
193	movl %eax, %cr0
194	movl ESP(%edi), %esp
195	movl %ebp, %eax
196
197	popf
198	popl %ebp
199	popl %edi
200	popl %esi
201	popl %ebx
202	ret
203
5033cba0	204	/* Do the copies */
3ab83521 HY	205	swap_pages:
	206	movl 8(%esp), %edx
	207	movl 4(%esp), %ecx
	208	pushl %ebp
	209	pushl %ebx
	210	pushl %edi
	211	pushl %esi
	212	movl %ecx, %ebx
5033cba0 EB	213	jmp 1f
	214
	215	0: /* top, read another word from the indirection page */
	216	movl (%ebx), %ecx
	217	addl $4, %ebx
	218	1:
	219	testl $0x1, %ecx /* is it a destination page */
	220	jz 2f
	221	movl %ecx, %edi
	222	andl $0xfffff000, %edi
	223	jmp 0b
	224	2:
	225	testl $0x2, %ecx /* is it an indirection page */
	226	jz 2f
	227	movl %ecx, %ebx
	228	andl $0xfffff000, %ebx
	229	jmp 0b
	230	2:
	231	testl $0x4, %ecx /* is it the done indicator */
	232	jz 2f
	233	jmp 3f
	234	2:
	235	testl $0x8, %ecx /* is it the source indicator */
	236	jz 0b /* Ignore it otherwise */
	237	movl %ecx, %esi /* For every source page do a copy */
	238	andl $0xfffff000, %esi
	239
3ab83521 HY	240	movl %edi, %eax
	241	movl %esi, %ebp
	242
	243	movl %edx, %edi
5033cba0 EB	244	movl $1024, %ecx
5033cba0 EB	245	rep ; movsl
5033cba0	246
3ab83521 HY	247	movl %ebp, %edi
	248	movl %eax, %esi
	249	movl $1024, %ecx
	250	rep ; movsl
5033cba0	251
3ab83521 HY	252	movl %eax, %edi
	253	movl %edx, %esi
	254	movl $1024, %ecx
	255	rep ; movsl
5033cba0	256
3ab83521 HY	257	lea PAGE_SIZE(%ebp), %esi
	258	jmp 0b
	259	3:
	260	popl %esi
	261	popl %edi
	262	popl %ebx
	263	popl %ebp
5033cba0	264	ret
fb45daa6 HY	265
	266	.globl kexec_control_code_size
	267	.set kexec_control_code_size, . - relocate_kernel