| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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 |
| */ |
| |
| #include <linux/gfp.h> |
| #include <linux/suspend.h> |
| #include <linux/memblock.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; |
| p4d_t *p4d; |
| pmd_t *pmd_table; |
| |
| p4d = p4d_offset(pgd, 0); |
| pud = pud_offset(p4d, 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(); |
| } |