/* * linux/arch/unicore32/kernel/hibernate.c * * Code specific to PKUnity SoC and UniCore ISA * * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> * Copyright (C) 2001-2010 Guan Xuetao * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/gfp.h> #include <linux/suspend.h> #include <linux/bootmem.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> #include <asm/sections.h> #include <asm/suspend.h> #include "mach/pm.h" /* Pointer to the temporary resume page tables */ pgd_t *resume_pg_dir; struct swsusp_arch_regs swsusp_arch_regs_cpu0; /* * 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; pud = pud_offset(pgd, 0); pmd_table = pmd_offset(pud, 0); 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_KERNEL_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++) { pte_t *max_pte; if (pfn >= max_low_pfn) break; /* Map with normal page tables. * NOTE: We can mark everything as executable here */ 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) { } 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(resume_pg_dir, restore_pblist); return 0; } /* * pfn_is_nosave - check if given pfn is in the 'nosave' section */ int pfn_is_nosave(unsigned long pfn) { unsigned long begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT; unsigned long end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT; return (pfn >= begin_pfn) && (pfn < end_pfn); } void save_processor_state(void) { } void restore_processor_state(void) { local_flush_tlb_all(); }