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Commit 9868ee63 authored by Huang Ying's avatar Huang Ying Committed by Ingo Molnar
Browse files

kexec/i386: setup kexec page table in C 



Impact: change the kexec bootstrap code implementation from assembly to C

This patch transforms the kexec page tables setup code from assembler
code to C code in machine_kexec_prepare. This improves readability and
reduces code line number.

Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 92be3d6b

arch/x86/include/asm/kexec.h

+2 −15
Original line number Diff line number Diff line
@@ -5,21 +5,8 @@ 
# define PA_CONTROL_PAGE	0

# define VA_CONTROL_PAGE	1

# define PA_PGD			2

# define VA_PGD			3

# define PA_PTE_0		4

# define VA_PTE_0		5

# define PA_PTE_1		6

# define VA_PTE_1		7

# define PA_SWAP_PAGE		8

# ifdef CONFIG_X86_PAE

#  define PA_PMD_0		9

#  define VA_PMD_0		10

#  define PA_PMD_1		11

#  define VA_PMD_1		12

#  define PAGES_NR		13

# else

#  define PAGES_NR		9

# endif

# define PA_SWAP_PAGE		3

# define PAGES_NR		4

#else

# define PA_CONTROL_PAGE	0

# define VA_CONTROL_PAGE	1

arch/x86/kernel/machine_kexec_32.c

+47 −12
Original line number Diff line number Diff line
@@ -99,6 +99,45 @@ static int machine_kexec_alloc_page_tables(struct kimage *image) 
	return 0;

}



static void machine_kexec_page_table_set_one(

	pgd_t *pgd, pmd_t *pmd, pte_t *pte,

	unsigned long vaddr, unsigned long paddr)

{

	pud_t *pud;



	pgd += pgd_index(vaddr);

#ifdef CONFIG_X86_PAE

	if (!(pgd_val(*pgd) & _PAGE_PRESENT))

		set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));

#endif

	pud = pud_offset(pgd, vaddr);

	pmd = pmd_offset(pud, vaddr);

	if (!(pmd_val(*pmd) & _PAGE_PRESENT))

		set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));

	pte = pte_offset_kernel(pmd, vaddr);

	set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));

}



static void machine_kexec_prepare_page_tables(struct kimage *image)

{

	void *control_page;

	pmd_t *pmd = 0;



	control_page = page_address(image->control_code_page);

#ifdef CONFIG_X86_PAE

	pmd = image->arch.pmd0;

#endif

	machine_kexec_page_table_set_one(

		image->arch.pgd, pmd, image->arch.pte0,

		(unsigned long)control_page, __pa(control_page));

#ifdef CONFIG_X86_PAE

	pmd = image->arch.pmd1;

#endif

	machine_kexec_page_table_set_one(

		image->arch.pgd, pmd, image->arch.pte1,

		__pa(control_page), __pa(control_page));

}



/*

 * A architecture hook called to validate the

 * proposed image and prepare the control pages
@@ -112,12 +151,19 @@ static int machine_kexec_alloc_page_tables(struct kimage *image) 
 *

 * - Make control page executable.

 * - Allocate page tables

 * - Setup page tables

 */

int machine_kexec_prepare(struct kimage *image)

{

	int error;



	if (nx_enabled)

		set_pages_x(image->control_code_page, 1);

	return machine_kexec_alloc_page_tables(image);

	error = machine_kexec_alloc_page_tables(image);

	if (error)

		return error;

	machine_kexec_prepare_page_tables(image);

	return 0;

}



/*
@@ -176,17 +222,6 @@ void machine_kexec(struct kimage *image) 
	page_list[PA_CONTROL_PAGE] = __pa(control_page);

	page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;

	page_list[PA_PGD] = __pa(image->arch.pgd);

	page_list[VA_PGD] = (unsigned long)image->arch.pgd;

#ifdef CONFIG_X86_PAE

	page_list[PA_PMD_0] = __pa(image->arch.pmd0);

	page_list[VA_PMD_0] = (unsigned long)image->arch.pmd0;

	page_list[PA_PMD_1] = __pa(image->arch.pmd1);

	page_list[VA_PMD_1] = (unsigned long)image->arch.pmd1;

#endif

	page_list[PA_PTE_0] = __pa(image->arch.pte0);

	page_list[VA_PTE_0] = (unsigned long)image->arch.pte0;

	page_list[PA_PTE_1] = __pa(image->arch.pte1);

	page_list[VA_PTE_1] = (unsigned long)image->arch.pte1;



	if (image->type == KEXEC_TYPE_DEFAULT)

		page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)

arch/x86/kernel/relocate_kernel_32.S

+0 −114
Original line number Diff line number Diff line
@@ -10,15 +10,12 @@ 
#include <asm/page.h>

#include <asm/kexec.h>

#include <asm/processor-flags.h>

#include <asm/pgtable.h>



/*

 * Must be relocatable PIC code callable as a C function

 */



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

#define PAGE_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)

#define PAE_PGD_ATTR (_PAGE_PRESENT)



/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE

 * ~ control_page + PAGE_SIZE are used as data storage and stack for
@@ -59,117 +56,6 @@ relocate_kernel: 
	movl	%cr4, %eax

	movl	%eax, CR4(%edi)



#ifdef CONFIG_X86_PAE

	/* map the control page at its virtual address */



	movl	PTR(VA_PGD)(%ebp), %edi

	movl	PTR(VA_CONTROL_PAGE)(%ebp), %eax

	andl	$0xc0000000, %eax

	shrl	$27, %eax

	addl	%edi, %eax



	movl	PTR(PA_PMD_0)(%ebp), %edx

	orl	$PAE_PGD_ATTR, %edx

	movl	%edx, (%eax)



	movl	PTR(VA_PMD_0)(%ebp), %edi

	movl	PTR(VA_CONTROL_PAGE)(%ebp), %eax

	andl	$0x3fe00000, %eax

	shrl	$18, %eax

	addl	%edi, %eax



	movl	PTR(PA_PTE_0)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)



	movl	PTR(VA_PTE_0)(%ebp), %edi

	movl	PTR(VA_CONTROL_PAGE)(%ebp), %eax

	andl	$0x001ff000, %eax

	shrl	$9, %eax

	addl	%edi, %eax



	movl	PTR(PA_CONTROL_PAGE)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)



	/* identity map the control page at its physical address */



	movl	PTR(VA_PGD)(%ebp), %edi

	movl	PTR(PA_CONTROL_PAGE)(%ebp), %eax

	andl	$0xc0000000, %eax

	shrl	$27, %eax

	addl	%edi, %eax



	movl	PTR(PA_PMD_1)(%ebp), %edx

	orl	$PAE_PGD_ATTR, %edx

	movl	%edx, (%eax)



	movl	PTR(VA_PMD_1)(%ebp), %edi

	movl	PTR(PA_CONTROL_PAGE)(%ebp), %eax

	andl	$0x3fe00000, %eax

	shrl	$18, %eax

	addl	%edi, %eax



	movl	PTR(PA_PTE_1)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)



	movl	PTR(VA_PTE_1)(%ebp), %edi

	movl	PTR(PA_CONTROL_PAGE)(%ebp), %eax

	andl	$0x001ff000, %eax

	shrl	$9, %eax

	addl	%edi, %eax



	movl	PTR(PA_CONTROL_PAGE)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)

#else

	/* map the control page at its virtual address */



	movl	PTR(VA_PGD)(%ebp), %edi

	movl	PTR(VA_CONTROL_PAGE)(%ebp), %eax

	andl	$0xffc00000, %eax

	shrl	$20, %eax

	addl	%edi, %eax



	movl	PTR(PA_PTE_0)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)



	movl	PTR(VA_PTE_0)(%ebp), %edi

	movl	PTR(VA_CONTROL_PAGE)(%ebp), %eax

	andl	$0x003ff000, %eax

	shrl	$10, %eax

	addl	%edi, %eax



	movl	PTR(PA_CONTROL_PAGE)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)



	/* identity map the control page at its physical address */



	movl	PTR(VA_PGD)(%ebp), %edi

	movl	PTR(PA_CONTROL_PAGE)(%ebp), %eax

	andl	$0xffc00000, %eax

	shrl	$20, %eax

	addl	%edi, %eax



	movl	PTR(PA_PTE_1)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)



	movl	PTR(VA_PTE_1)(%ebp), %edi

	movl	PTR(PA_CONTROL_PAGE)(%ebp), %eax

	andl	$0x003ff000, %eax

	shrl	$10, %eax

	addl	%edi, %eax



	movl	PTR(PA_CONTROL_PAGE)(%ebp), %edx

	orl	$PAGE_ATTR, %edx

	movl	%edx, (%eax)

#endif



relocate_new_kernel:

	/* read the arguments and say goodbye to the stack */

	movl  20+4(%esp), %ebx /* page_list */

	movl  20+8(%esp), %ebp /* list of pages */