Transitional page tables provide the needed functionality to setup temporary page tables needed for hibernate resume.
Signed-off-by: Pavel Tatashin <[email protected]> --- arch/arm64/kernel/hibernate.c | 261 ++++++++-------------------------- 1 file changed, 60 insertions(+), 201 deletions(-) diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c index 9341fcc6e809..4120b03a02fd 100644 --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -16,7 +16,6 @@ #define pr_fmt(x) "hibernate: " x #include <linux/cpu.h> #include <linux/kvm_host.h> -#include <linux/mm.h> #include <linux/pm.h> #include <linux/sched.h> #include <linux/suspend.h> @@ -31,14 +30,12 @@ #include <asm/kexec.h> #include <asm/memory.h> #include <asm/mmu_context.h> -#include <asm/pgalloc.h> -#include <asm/pgtable.h> -#include <asm/pgtable-hwdef.h> #include <asm/sections.h> #include <asm/smp.h> #include <asm/smp_plat.h> #include <asm/suspend.h> #include <asm/sysreg.h> +#include <asm/trans_table.h> #include <asm/virt.h> /* @@ -182,6 +179,12 @@ int arch_hibernation_header_restore(void *addr) } EXPORT_SYMBOL(arch_hibernation_header_restore); +static void * +hibernate_page_alloc(void *arg) +{ + return (void *)get_safe_page((gfp_t)(unsigned long)arg); +} + /* * Copies length bytes, starting at src_start into an new page, * perform cache maintentance, then maps it at the specified address low @@ -196,57 +199,31 @@ EXPORT_SYMBOL(arch_hibernation_header_restore); */ static int create_safe_exec_page(void *src_start, size_t length, unsigned long dst_addr, - phys_addr_t *phys_dst_addr, - void *(*allocator)(gfp_t mask), - gfp_t mask) + phys_addr_t *phys_dst_addr) { - int rc = 0; - pgd_t *pgdp; - pud_t *pudp; - pmd_t *pmdp; - pte_t *ptep; - unsigned long dst = (unsigned long)allocator(mask); - - if (!dst) { - rc = -ENOMEM; - goto out; - } - - memcpy((void *)dst, src_start, length); - __flush_icache_range(dst, dst + length); + struct trans_table_info trans_info = { + .trans_alloc_page = hibernate_page_alloc, + .trans_alloc_arg = (void *)GFP_ATOMIC, + .trans_flags = 0, + }; + void *page = (void *)get_safe_page(GFP_ATOMIC); + pgd_t *trans_table; + int rc; + + if (!page) + return -ENOMEM; - pgdp = pgd_offset_raw(allocator(mask), dst_addr); - if (pgd_none(READ_ONCE(*pgdp))) { - pudp = allocator(mask); - if (!pudp) { - rc = -ENOMEM; - goto out; - } - pgd_populate(&init_mm, pgdp, pudp); - } + memcpy(page, src_start, length); + __flush_icache_range((unsigned long)page, (unsigned long)page + length); - pudp = pud_offset(pgdp, dst_addr); - if (pud_none(READ_ONCE(*pudp))) { - pmdp = allocator(mask); - if (!pmdp) { - rc = -ENOMEM; - goto out; - } - pud_populate(&init_mm, pudp, pmdp); - } - - pmdp = pmd_offset(pudp, dst_addr); - if (pmd_none(READ_ONCE(*pmdp))) { - ptep = allocator(mask); - if (!ptep) { - rc = -ENOMEM; - goto out; - } - pmd_populate_kernel(&init_mm, pmdp, ptep); - } + rc = trans_table_create_empty(&trans_info, &trans_table); + if (rc) + return rc; - ptep = pte_offset_kernel(pmdp, dst_addr); - set_pte(ptep, pfn_pte(virt_to_pfn(dst), PAGE_KERNEL_EXEC)); + rc = trans_table_map_page(&trans_info, trans_table, page, dst_addr, + PAGE_KERNEL_EXEC); + if (rc) + return rc; /* * Load our new page tables. A strict BBM approach requires that we @@ -262,13 +239,12 @@ static int create_safe_exec_page(void *src_start, size_t length, */ cpu_set_reserved_ttbr0(); local_flush_tlb_all(); - write_sysreg(phys_to_ttbr(virt_to_phys(pgdp)), ttbr0_el1); + write_sysreg(phys_to_ttbr(virt_to_phys(trans_table)), ttbr0_el1); isb(); - *phys_dst_addr = virt_to_phys((void *)dst); + *phys_dst_addr = virt_to_phys(page); -out: - return rc; + return 0; } #define dcache_clean_range(start, end) __flush_dcache_area(start, (end - start)) @@ -332,143 +308,6 @@ int swsusp_arch_suspend(void) return ret; } -static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr) -{ - pte_t pte = READ_ONCE(*src_ptep); - - if (pte_valid(pte)) { - /* - * Resume will overwrite areas that may be marked - * read only (code, rodata). Clear the RDONLY bit from - * the temporary mappings we use during restore. - */ - set_pte(dst_ptep, pte_mkwrite(pte)); - } else if (debug_pagealloc_enabled() && !pte_none(pte)) { - /* - * debug_pagealloc will removed the PTE_VALID bit if - * the page isn't in use by the resume kernel. It may have - * been in use by the original kernel, in which case we need - * to put it back in our copy to do the restore. - * - * Before marking this entry valid, check the pfn should - * be mapped. - */ - BUG_ON(!pfn_valid(pte_pfn(pte))); - - set_pte(dst_ptep, pte_mkpresent(pte_mkwrite(pte))); - } -} - -static int copy_pte(pmd_t *dst_pmdp, pmd_t *src_pmdp, unsigned long start, - unsigned long end) -{ - pte_t *src_ptep; - pte_t *dst_ptep; - unsigned long addr = start; - - dst_ptep = (pte_t *)get_safe_page(GFP_ATOMIC); - if (!dst_ptep) - return -ENOMEM; - pmd_populate_kernel(&init_mm, dst_pmdp, dst_ptep); - dst_ptep = pte_offset_kernel(dst_pmdp, start); - - src_ptep = pte_offset_kernel(src_pmdp, start); - do { - _copy_pte(dst_ptep, src_ptep, addr); - } while (dst_ptep++, src_ptep++, addr += PAGE_SIZE, addr != end); - - return 0; -} - -static int copy_pmd(pud_t *dst_pudp, pud_t *src_pudp, unsigned long start, - unsigned long end) -{ - pmd_t *src_pmdp; - pmd_t *dst_pmdp; - unsigned long next; - unsigned long addr = start; - - if (pud_none(READ_ONCE(*dst_pudp))) { - dst_pmdp = (pmd_t *)get_safe_page(GFP_ATOMIC); - if (!dst_pmdp) - return -ENOMEM; - pud_populate(&init_mm, dst_pudp, dst_pmdp); - } - dst_pmdp = pmd_offset(dst_pudp, start); - - src_pmdp = pmd_offset(src_pudp, start); - do { - pmd_t pmd = READ_ONCE(*src_pmdp); - - next = pmd_addr_end(addr, end); - if (pmd_none(pmd)) - continue; - if (pmd_table(pmd)) { - if (copy_pte(dst_pmdp, src_pmdp, addr, next)) - return -ENOMEM; - } else { - set_pmd(dst_pmdp, - __pmd(pmd_val(pmd) & ~PMD_SECT_RDONLY)); - } - } while (dst_pmdp++, src_pmdp++, addr = next, addr != end); - - return 0; -} - -static int copy_pud(pgd_t *dst_pgdp, pgd_t *src_pgdp, unsigned long start, - unsigned long end) -{ - pud_t *dst_pudp; - pud_t *src_pudp; - unsigned long next; - unsigned long addr = start; - - if (pgd_none(READ_ONCE(*dst_pgdp))) { - dst_pudp = (pud_t *)get_safe_page(GFP_ATOMIC); - if (!dst_pudp) - return -ENOMEM; - pgd_populate(&init_mm, dst_pgdp, dst_pudp); - } - dst_pudp = pud_offset(dst_pgdp, start); - - src_pudp = pud_offset(src_pgdp, start); - do { - pud_t pud = READ_ONCE(*src_pudp); - - next = pud_addr_end(addr, end); - if (pud_none(pud)) - continue; - if (pud_table(pud)) { - if (copy_pmd(dst_pudp, src_pudp, addr, next)) - return -ENOMEM; - } else { - set_pud(dst_pudp, - __pud(pud_val(pud) & ~PMD_SECT_RDONLY)); - } - } while (dst_pudp++, src_pudp++, addr = next, addr != end); - - return 0; -} - -static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start, - unsigned long end) -{ - unsigned long next; - unsigned long addr = start; - pgd_t *src_pgdp = pgd_offset_k(start); - - dst_pgdp = pgd_offset_raw(dst_pgdp, start); - do { - next = pgd_addr_end(addr, end); - if (pgd_none(READ_ONCE(*src_pgdp))) - continue; - if (copy_pud(dst_pgdp, src_pgdp, addr, next)) - return -ENOMEM; - } while (dst_pgdp++, src_pgdp++, addr = next, addr != end); - - return 0; -} - /* * Setup then Resume from the hibernate image using swsusp_arch_suspend_exit(). * @@ -484,21 +323,42 @@ int swsusp_arch_resume(void) phys_addr_t phys_hibernate_exit; void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *, void *, phys_addr_t, phys_addr_t); + struct trans_table_info trans_info = { + .trans_alloc_page = hibernate_page_alloc, + .trans_alloc_arg = (void *)GFP_ATOMIC, + /* + * Resume will overwrite areas that may be marked read only + * (code, rodata). Clear the RDONLY bit from the temporary + * mappings we use during restore. + */ + .trans_flags = TRANS_MKWRITE, + }; + + /* + * debug_pagealloc will removed the PTE_VALID bit if the page isn't in + * use by the resume kernel. It may have been in use by the original + * kernel, in which case we need to put it back in our copy to do the + * restore. + * + * Before marking this entry valid, check the pfn should be mapped. + */ + if (debug_pagealloc_enabled()) + trans_info.trans_flags |= (TRANS_MKVALID | TRANS_CHECKPFN); /* * Restoring the memory image will overwrite the ttbr1 page tables. * Create a second copy of just the linear map, and use this when * restoring. */ - tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC); - if (!tmp_pg_dir) { - pr_err("Failed to allocate memory for temporary page tables.\n"); - rc = -ENOMEM; + rc = trans_table_create_copy(&trans_info, &tmp_pg_dir, + pgd_offset_k(PAGE_OFFSET), PAGE_OFFSET, 0); + if (rc) { + if (rc == -ENOMEM) + pr_err("Failed to allocate memory for temporary page tables.\n"); + else if (rc == -ENXIO) + pr_err("Tried to set PTE for PFN that does not exist\n"); goto out; } - rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, 0); - if (rc) - goto out; /* * We need a zero page that is zero before & after resume in order to @@ -523,8 +383,7 @@ int swsusp_arch_resume(void) */ rc = create_safe_exec_page(__hibernate_exit_text_start, exit_size, (unsigned long)hibernate_exit, - &phys_hibernate_exit, - (void *)get_safe_page, GFP_ATOMIC); + &phys_hibernate_exit); if (rc) { pr_err("Failed to create safe executable page for hibernate_exit code.\n"); goto out; -- 2.22.0
