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198 lines
4.3 KiB
198 lines
4.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Hibernation support specific for i386 - temporary page tables |
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* |
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* Copyright (c) 2006 Rafael J. Wysocki <[email protected]> |
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*/ |
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#include <linux/gfp.h> |
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#include <linux/suspend.h> |
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#include <linux/memblock.h> |
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#include <linux/pgtable.h> |
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#include <asm/page.h> |
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#include <asm/mmzone.h> |
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#include <asm/sections.h> |
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#include <asm/suspend.h> |
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/* Pointer to the temporary resume page tables */ |
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pgd_t *resume_pg_dir; |
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/* The following three functions are based on the analogous code in |
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* arch/x86/mm/init_32.c |
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*/ |
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/* |
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* Create a middle page table on a resume-safe page and put a pointer to it in |
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* the given global directory entry. This only returns the gd entry |
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* in non-PAE compilation mode, since the middle layer is folded. |
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*/ |
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static pmd_t *resume_one_md_table_init(pgd_t *pgd) |
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{ |
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p4d_t *p4d; |
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pud_t *pud; |
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pmd_t *pmd_table; |
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#ifdef CONFIG_X86_PAE |
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pmd_table = (pmd_t *)get_safe_page(GFP_ATOMIC); |
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if (!pmd_table) |
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return NULL; |
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set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); |
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p4d = p4d_offset(pgd, 0); |
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pud = pud_offset(p4d, 0); |
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BUG_ON(pmd_table != pmd_offset(pud, 0)); |
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#else |
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p4d = p4d_offset(pgd, 0); |
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pud = pud_offset(p4d, 0); |
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pmd_table = pmd_offset(pud, 0); |
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#endif |
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return pmd_table; |
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} |
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/* |
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* Create a page table on a resume-safe page and place a pointer to it in |
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* a middle page directory entry. |
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*/ |
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static pte_t *resume_one_page_table_init(pmd_t *pmd) |
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{ |
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if (pmd_none(*pmd)) { |
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pte_t *page_table = (pte_t *)get_safe_page(GFP_ATOMIC); |
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if (!page_table) |
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return NULL; |
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set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); |
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BUG_ON(page_table != pte_offset_kernel(pmd, 0)); |
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return page_table; |
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} |
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return pte_offset_kernel(pmd, 0); |
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} |
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/* |
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* This maps the physical memory to kernel virtual address space, a total |
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* of max_low_pfn pages, by creating page tables starting from address |
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* PAGE_OFFSET. The page tables are allocated out of resume-safe pages. |
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*/ |
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static int resume_physical_mapping_init(pgd_t *pgd_base) |
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{ |
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unsigned long pfn; |
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pgd_t *pgd; |
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pmd_t *pmd; |
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pte_t *pte; |
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int pgd_idx, pmd_idx; |
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pgd_idx = pgd_index(PAGE_OFFSET); |
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pgd = pgd_base + pgd_idx; |
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pfn = 0; |
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for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { |
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pmd = resume_one_md_table_init(pgd); |
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if (!pmd) |
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return -ENOMEM; |
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if (pfn >= max_low_pfn) |
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continue; |
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for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD; pmd++, pmd_idx++) { |
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if (pfn >= max_low_pfn) |
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break; |
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/* Map with big pages if possible, otherwise create |
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* normal page tables. |
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* NOTE: We can mark everything as executable here |
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*/ |
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if (boot_cpu_has(X86_FEATURE_PSE)) { |
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set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC)); |
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pfn += PTRS_PER_PTE; |
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} else { |
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pte_t *max_pte; |
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pte = resume_one_page_table_init(pmd); |
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if (!pte) |
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return -ENOMEM; |
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max_pte = pte + PTRS_PER_PTE; |
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for (; pte < max_pte; pte++, pfn++) { |
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if (pfn >= max_low_pfn) |
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break; |
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set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); |
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} |
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} |
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} |
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} |
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return 0; |
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} |
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static inline void resume_init_first_level_page_table(pgd_t *pg_dir) |
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{ |
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#ifdef CONFIG_X86_PAE |
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int i; |
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/* Init entries of the first-level page table to the zero page */ |
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for (i = 0; i < PTRS_PER_PGD; i++) |
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set_pgd(pg_dir + i, |
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__pgd(__pa(empty_zero_page) | _PAGE_PRESENT)); |
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#endif |
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} |
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static int set_up_temporary_text_mapping(pgd_t *pgd_base) |
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{ |
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pgd_t *pgd; |
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pmd_t *pmd; |
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pte_t *pte; |
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pgd = pgd_base + pgd_index(restore_jump_address); |
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pmd = resume_one_md_table_init(pgd); |
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if (!pmd) |
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return -ENOMEM; |
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if (boot_cpu_has(X86_FEATURE_PSE)) { |
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set_pmd(pmd + pmd_index(restore_jump_address), |
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__pmd((jump_address_phys & PMD_MASK) | pgprot_val(PAGE_KERNEL_LARGE_EXEC))); |
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} else { |
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pte = resume_one_page_table_init(pmd); |
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if (!pte) |
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return -ENOMEM; |
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set_pte(pte + pte_index(restore_jump_address), |
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__pte((jump_address_phys & PAGE_MASK) | pgprot_val(PAGE_KERNEL_EXEC))); |
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} |
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return 0; |
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} |
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asmlinkage int swsusp_arch_resume(void) |
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{ |
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int error; |
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resume_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC); |
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if (!resume_pg_dir) |
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return -ENOMEM; |
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resume_init_first_level_page_table(resume_pg_dir); |
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error = set_up_temporary_text_mapping(resume_pg_dir); |
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if (error) |
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return error; |
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error = resume_physical_mapping_init(resume_pg_dir); |
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if (error) |
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return error; |
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temp_pgt = __pa(resume_pg_dir); |
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error = relocate_restore_code(); |
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if (error) |
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return error; |
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/* We have got enough memory and from now on we cannot recover */ |
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restore_image(); |
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return 0; |
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}
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