177 lines
3.9 KiB
C
177 lines
3.9 KiB
C
/*
|
|
* Hibernation support specific for i386 - temporary page tables
|
|
*
|
|
* Distribute under GPLv2
|
|
*
|
|
* Copyright (c) 2006 Rafael J. Wysocki <rjw@sisk.pl>
|
|
*/
|
|
|
|
#include <linux/suspend.h>
|
|
#include <linux/bootmem.h>
|
|
|
|
#include <asm/system.h>
|
|
#include <asm/page.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/mmzone.h>
|
|
|
|
/* Defined in hibernate_asm_32.S */
|
|
extern int restore_image(void);
|
|
|
|
/* References to section boundaries */
|
|
extern const void __nosave_begin, __nosave_end;
|
|
|
|
/* Pointer to the temporary resume page tables */
|
|
pgd_t *resume_pg_dir;
|
|
|
|
/* The following three functions are based on the analogous code in
|
|
* arch/x86/mm/init_32.c
|
|
*/
|
|
|
|
/*
|
|
* Create a middle page table on a resume-safe page and put a pointer to it in
|
|
* the given global directory entry. This only returns the gd entry
|
|
* in non-PAE compilation mode, since the middle layer is folded.
|
|
*/
|
|
static pmd_t *resume_one_md_table_init(pgd_t *pgd)
|
|
{
|
|
pud_t *pud;
|
|
pmd_t *pmd_table;
|
|
|
|
#ifdef CONFIG_X86_PAE
|
|
pmd_table = (pmd_t *)get_safe_page(GFP_ATOMIC);
|
|
if (!pmd_table)
|
|
return NULL;
|
|
|
|
set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
|
|
pud = pud_offset(pgd, 0);
|
|
|
|
BUG_ON(pmd_table != pmd_offset(pud, 0));
|
|
#else
|
|
pud = pud_offset(pgd, 0);
|
|
pmd_table = pmd_offset(pud, 0);
|
|
#endif
|
|
|
|
return pmd_table;
|
|
}
|
|
|
|
/*
|
|
* Create a page table on a resume-safe page and place a pointer to it in
|
|
* a middle page directory entry.
|
|
*/
|
|
static pte_t *resume_one_page_table_init(pmd_t *pmd)
|
|
{
|
|
if (pmd_none(*pmd)) {
|
|
pte_t *page_table = (pte_t *)get_safe_page(GFP_ATOMIC);
|
|
if (!page_table)
|
|
return NULL;
|
|
|
|
set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
|
|
|
|
BUG_ON(page_table != pte_offset_kernel(pmd, 0));
|
|
|
|
return page_table;
|
|
}
|
|
|
|
return pte_offset_kernel(pmd, 0);
|
|
}
|
|
|
|
/*
|
|
* This maps the physical memory to kernel virtual address space, a total
|
|
* of max_low_pfn pages, by creating page tables starting from address
|
|
* PAGE_OFFSET. The page tables are allocated out of resume-safe pages.
|
|
*/
|
|
static int resume_physical_mapping_init(pgd_t *pgd_base)
|
|
{
|
|
unsigned long pfn;
|
|
pgd_t *pgd;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
int pgd_idx, pmd_idx;
|
|
|
|
pgd_idx = pgd_index(PAGE_OFFSET);
|
|
pgd = pgd_base + pgd_idx;
|
|
pfn = 0;
|
|
|
|
for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
|
|
pmd = resume_one_md_table_init(pgd);
|
|
if (!pmd)
|
|
return -ENOMEM;
|
|
|
|
if (pfn >= max_low_pfn)
|
|
continue;
|
|
|
|
for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD; pmd++, pmd_idx++) {
|
|
if (pfn >= max_low_pfn)
|
|
break;
|
|
|
|
/* Map with big pages if possible, otherwise create
|
|
* normal page tables.
|
|
* NOTE: We can mark everything as executable here
|
|
*/
|
|
if (cpu_has_pse) {
|
|
set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
|
|
pfn += PTRS_PER_PTE;
|
|
} else {
|
|
pte_t *max_pte;
|
|
|
|
pte = resume_one_page_table_init(pmd);
|
|
if (!pte)
|
|
return -ENOMEM;
|
|
|
|
max_pte = pte + PTRS_PER_PTE;
|
|
for (; pte < max_pte; pte++, pfn++) {
|
|
if (pfn >= max_low_pfn)
|
|
break;
|
|
|
|
set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
resume_map_numa_kva(pgd_base);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline void resume_init_first_level_page_table(pgd_t *pg_dir)
|
|
{
|
|
#ifdef CONFIG_X86_PAE
|
|
int i;
|
|
|
|
/* Init entries of the first-level page table to the zero page */
|
|
for (i = 0; i < PTRS_PER_PGD; i++)
|
|
set_pgd(pg_dir + i,
|
|
__pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
|
|
#endif
|
|
}
|
|
|
|
int swsusp_arch_resume(void)
|
|
{
|
|
int error;
|
|
|
|
resume_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
|
|
if (!resume_pg_dir)
|
|
return -ENOMEM;
|
|
|
|
resume_init_first_level_page_table(resume_pg_dir);
|
|
error = resume_physical_mapping_init(resume_pg_dir);
|
|
if (error)
|
|
return error;
|
|
|
|
/* We have got enough memory and from now on we cannot recover */
|
|
restore_image();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* pfn_is_nosave - check if given pfn is in the 'nosave' section
|
|
*/
|
|
|
|
int pfn_is_nosave(unsigned long pfn)
|
|
{
|
|
unsigned long nosave_begin_pfn = __pa_symbol(&__nosave_begin) >> PAGE_SHIFT;
|
|
unsigned long nosave_end_pfn = PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT;
|
|
return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
|
|
}
|