diff options
| -rw-r--r-- | arch/x86_64/kernel/suspend.c | 127 | ||||
| -rw-r--r-- | arch/x86_64/kernel/suspend_asm.S | 17 | ||||
| -rw-r--r-- | include/linux/suspend.h | 2 | ||||
| -rw-r--r-- | kernel/power/swsusp.c | 7 |
4 files changed, 144 insertions, 9 deletions
diff --git a/arch/x86_64/kernel/suspend.c b/arch/x86_64/kernel/suspend.c index ebb9abf3ce6..f066c6ab361 100644 --- a/arch/x86_64/kernel/suspend.c +++ b/arch/x86_64/kernel/suspend.c @@ -11,6 +11,8 @@ #include <linux/smp.h> #include <linux/suspend.h> #include <asm/proto.h> +#include <asm/page.h> +#include <asm/pgtable.h> struct saved_context saved_context; @@ -140,4 +142,129 @@ void fix_processor_context(void) } +#ifdef CONFIG_SOFTWARE_SUSPEND +/* Defined in arch/x86_64/kernel/suspend_asm.S */ +extern int restore_image(void); +pgd_t *temp_level4_pgt; + +static void **pages; + +static inline void *__add_page(void) +{ + void **c; + + c = (void **)get_usable_page(GFP_ATOMIC); + if (c) { + *c = pages; + pages = c; + } + return c; +} + +static inline void *__next_page(void) +{ + void **c; + + c = pages; + if (c) { + pages = *c; + *c = NULL; + } + return c; +} + +/* + * Try to allocate as many usable pages as needed and daisy chain them. + * If one allocation fails, free the pages allocated so far + */ +static int alloc_usable_pages(unsigned long n) +{ + void *p; + + pages = NULL; + do + if (!__add_page()) + break; + while (--n); + if (n) { + p = __next_page(); + while (p) { + free_page((unsigned long)p); + p = __next_page(); + } + return -ENOMEM; + } + return 0; +} + +static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end) +{ + long i, j; + + i = pud_index(address); + pud = pud + i; + for (; i < PTRS_PER_PUD; pud++, i++) { + unsigned long paddr; + pmd_t *pmd; + + paddr = address + i*PUD_SIZE; + if (paddr >= end) + break; + + pmd = (pmd_t *)__next_page(); + set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); + for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) { + unsigned long pe; + + if (paddr >= end) + break; + pe = _PAGE_NX | _PAGE_PSE | _KERNPG_TABLE | paddr; + pe &= __supported_pte_mask; + set_pmd(pmd, __pmd(pe)); + } + } +} + +static void set_up_temporary_mappings(void) +{ + unsigned long start, end, next; + + temp_level4_pgt = (pgd_t *)__next_page(); + + /* It is safe to reuse the original kernel mapping */ + set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map), + init_level4_pgt[pgd_index(__START_KERNEL_map)]); + + /* Set up the direct mapping from scratch */ + start = (unsigned long)pfn_to_kaddr(0); + end = (unsigned long)pfn_to_kaddr(end_pfn); + + for (; start < end; start = next) { + pud_t *pud = (pud_t *)__next_page(); + next = start + PGDIR_SIZE; + if (next > end) + next = end; + res_phys_pud_init(pud, __pa(start), __pa(next)); + set_pgd(temp_level4_pgt + pgd_index(start), + mk_kernel_pgd(__pa(pud))); + } +} + +int swsusp_arch_resume(void) +{ + unsigned long n; + + n = ((end_pfn << PAGE_SHIFT) + PUD_SIZE - 1) >> PUD_SHIFT; + n += (n + PTRS_PER_PUD - 1) / PTRS_PER_PUD + 1; + pr_debug("swsusp_arch_resume(): pages needed = %lu\n", n); + if (alloc_usable_pages(n)) { + free_eaten_memory(); + return -ENOMEM; + } + /* We have got enough memory and from now on we cannot recover */ + set_up_temporary_mappings(); + restore_image(); + return 0; +} +#endif /* CONFIG_SOFTWARE_SUSPEND */ diff --git a/arch/x86_64/kernel/suspend_asm.S b/arch/x86_64/kernel/suspend_asm.S index 4d659e97df1..320b6fb00cc 100644 --- a/arch/x86_64/kernel/suspend_asm.S +++ b/arch/x86_64/kernel/suspend_asm.S @@ -39,12 +39,13 @@ ENTRY(swsusp_arch_suspend) call swsusp_save ret -ENTRY(swsusp_arch_resume) - /* set up cr3 */ - leaq init_level4_pgt(%rip),%rax - subq $__START_KERNEL_map,%rax - movq %rax,%cr3 - +ENTRY(restore_image) + /* switch to temporary page tables */ + movq $__PAGE_OFFSET, %rdx + movq temp_level4_pgt(%rip), %rax + subq %rdx, %rax + movq %rax, %cr3 + /* Flush TLB */ movq mmu_cr4_features(%rip), %rax movq %rax, %rdx andq $~(1<<7), %rdx # PGE @@ -69,6 +70,10 @@ loop: movq pbe_next(%rdx), %rdx jmp loop done: + /* go back to the original page tables */ + leaq init_level4_pgt(%rip), %rax + subq $__START_KERNEL_map, %rax + movq %rax, %cr3 /* Flush TLB, including "global" things (vmalloc) */ movq mmu_cr4_features(%rip), %rax movq %rax, %rdx diff --git a/include/linux/suspend.h b/include/linux/suspend.h index f2e96fdfaae..ad15a54806d 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -71,5 +71,7 @@ void restore_processor_state(void); struct saved_context; void __save_processor_state(struct saved_context *ctxt); void __restore_processor_state(struct saved_context *ctxt); +extern unsigned long get_usable_page(unsigned gfp_mask); +extern void free_eaten_memory(void); #endif /* _LINUX_SWSUSP_H */ diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index acf79ac1cb6..2d5c4567644 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -1095,7 +1095,7 @@ static inline void eat_page(void *page) *eaten_memory = c; } -static unsigned long get_usable_page(unsigned gfp_mask) +unsigned long get_usable_page(unsigned gfp_mask) { unsigned long m; @@ -1109,7 +1109,7 @@ static unsigned long get_usable_page(unsigned gfp_mask) return m; } -static void free_eaten_memory(void) +void free_eaten_memory(void) { unsigned long m; void **c; @@ -1481,11 +1481,12 @@ static int read_suspend_image(void) /* Allocate memory for the image and read the data from swap */ error = check_pagedir(pagedir_nosave); - free_eaten_memory(); + if (!error) error = data_read(pagedir_nosave); if (error) { /* We fail cleanly */ + free_eaten_memory(); for_each_pbe (p, pagedir_nosave) if (p->address) { free_page(p->address); |