[PATCH] swsusp: Support i386 systems with PAE or without PSE (2d4a34c9) · Commits · 戴 / test

arch/i386/power/Makefile

+1 −1

Original line number	Diff line number	Diff line
		obj-$(CONFIG_PM) += cpu.o
		obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o
		obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o suspend.o

arch/i386/power/suspend.c

0 → 100644

+158 −0

Original line number	Diff line number	Diff line
		/*
		* Suspend 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>

		/* Defined in arch/i386/power/swsusp.S */
		extern int restore_image(void);

		/* Pointer to the temporary resume page tables */
		pgd_t *resume_pg_dir;

		/* The following three functions are based on the analogous code in
		* arch/i386/mm/init.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));
		}
		}
		}
		}
		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;
		}

arch/i386/power/swsusp.S

+7 −2

Original line number	Diff line number	Diff line
		@@ -28,8 +28,9 @@ ENTRY(swsusp_arch_suspend)
		call swsusp_save
		ret

		ENTRY(swsusp_arch_resume)
		movl $swsusp_pg_dir-__PAGE_OFFSET, %ecx
		ENTRY(restore_image)
		movl resume_pg_dir, %ecx
		subl $__PAGE_OFFSET, %ecx
		movl %ecx, %cr3

		movl restore_pblist, %edx
		@@ -51,6 +52,10 @@ copy_loop:
		.p2align 4,,7

		done:
		/* go back to the original page tables */
		movl $swapper_pg_dir, %ecx
		subl $__PAGE_OFFSET, %ecx
		movl %ecx, %cr3
		/* Flush TLB, including "global" things (vmalloc) */
		movl mmu_cr4_features, %eax
		movl %eax, %edx

include/asm-i386/suspend.h

+1 −12

Original line number	Diff line number	Diff line
		@@ -6,18 +6,7 @@
		#include <asm/desc.h>
		#include <asm/i387.h>

		static inline int
		arch_prepare_suspend(void)
		{
		/* If you want to make non-PSE machine work, turn off paging
		in swsusp_arch_suspend. swsusp_pg_dir should have identity mapping, so
		it could work... */
		if (!cpu_has_pse) {
		printk(KERN_ERR "PSE is required for swsusp.\n");
		return -EPERM;
		}
		return 0;
		}
		static inline int arch_prepare_suspend(void) { return 0; }

		/* image of the saved processor state */
		struct saved_context {

kernel/power/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -78,7 +78,7 @@ config PM_SYSFS_DEPRECATED

		config SOFTWARE_SUSPEND
		bool "Software Suspend"
		depends on PM && SWAP && ((X86 && (!SMP \|\| SUSPEND_SMP) && !X86_PAE) \|\| ((FRV \|\| PPC32) && !SMP))
		depends on PM && SWAP && ((X86 && (!SMP \|\| SUSPEND_SMP)) \|\| ((FRV \|\| PPC32) && !SMP))
		---help---
		Enable the possibility of suspending the machine.
		It doesn't need ACPI or APM.

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