From 59b3d0206d74a700069e49160e8194b2ca93b703 Mon Sep 17 00:00:00 2001 From: Thomas Garnier Date: Tue, 21 Jun 2016 17:46:59 -0700 Subject: x86/mm: Update physical mapping variable names Change the variable names in kernel_physical_mapping_init() and related functions to correctly reflect physical and virtual memory addresses. Also add comments on each function to describe usage and alignment constraints. Signed-off-by: Thomas Garnier Signed-off-by: Kees Cook Cc: Alexander Kuleshov Cc: Alexander Popov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Aneesh Kumar K.V Cc: Baoquan He Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Christian Borntraeger Cc: Dan Williams Cc: Dave Hansen Cc: Dave Young Cc: Denys Vlasenko Cc: Dmitry Vyukov Cc: H. Peter Anvin Cc: Jan Beulich Cc: Joerg Roedel Cc: Jonathan Corbet Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: Lv Zheng Cc: Mark Salter Cc: Martin Schwidefsky Cc: Matt Fleming Cc: Peter Zijlstra Cc: Stephen Smalley Cc: Thomas Gleixner Cc: Toshi Kani Cc: Xiao Guangrong Cc: Yinghai Lu Cc: kernel-hardening@lists.openwall.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/1466556426-32664-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 162 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 96 insertions(+), 66 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index bce2e5d9edd4..6714712bd5da 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -328,22 +328,30 @@ void __init cleanup_highmap(void) } } +/* + * Create PTE level page table mapping for physical addresses. + * It returns the last physical address mapped. + */ static unsigned long __meminit -phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, +phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end, pgprot_t prot) { - unsigned long pages = 0, next; - unsigned long last_map_addr = end; + unsigned long pages = 0, paddr_next; + unsigned long paddr_last = paddr_end; + pte_t *pte; int i; - pte_t *pte = pte_page + pte_index(addr); + pte = pte_page + pte_index(paddr); + i = pte_index(paddr); - for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) { - next = (addr & PAGE_MASK) + PAGE_SIZE; - if (addr >= end) { + for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) { + paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE; + if (paddr >= paddr_end) { if (!after_bootmem && - !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) && - !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN)) + !e820_any_mapped(paddr & PAGE_MASK, paddr_next, + E820_RAM) && + !e820_any_mapped(paddr & PAGE_MASK, paddr_next, + E820_RESERVED_KERN)) set_pte(pte, __pte(0)); continue; } @@ -361,37 +369,44 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, } if (0) - printk(" pte=%p addr=%lx pte=%016lx\n", - pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); + pr_info(" pte=%p addr=%lx pte=%016lx\n", pte, paddr, + pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte); pages++; - set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); - last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; + set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot)); + paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE; } update_page_count(PG_LEVEL_4K, pages); - return last_map_addr; + return paddr_last; } +/* + * Create PMD level page table mapping for physical addresses. The virtual + * and physical address have to be aligned at this level. + * It returns the last physical address mapped. + */ static unsigned long __meminit -phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, +phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end, unsigned long page_size_mask, pgprot_t prot) { - unsigned long pages = 0, next; - unsigned long last_map_addr = end; + unsigned long pages = 0, paddr_next; + unsigned long paddr_last = paddr_end; - int i = pmd_index(address); + int i = pmd_index(paddr); - for (; i < PTRS_PER_PMD; i++, address = next) { - pmd_t *pmd = pmd_page + pmd_index(address); + for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) { + pmd_t *pmd = pmd_page + pmd_index(paddr); pte_t *pte; pgprot_t new_prot = prot; - next = (address & PMD_MASK) + PMD_SIZE; - if (address >= end) { + paddr_next = (paddr & PMD_MASK) + PMD_SIZE; + if (paddr >= paddr_end) { if (!after_bootmem && - !e820_any_mapped(address & PMD_MASK, next, E820_RAM) && - !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN)) + !e820_any_mapped(paddr & PMD_MASK, paddr_next, + E820_RAM) && + !e820_any_mapped(paddr & PMD_MASK, paddr_next, + E820_RESERVED_KERN)) set_pmd(pmd, __pmd(0)); continue; } @@ -400,8 +415,8 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, if (!pmd_large(*pmd)) { spin_lock(&init_mm.page_table_lock); pte = (pte_t *)pmd_page_vaddr(*pmd); - last_map_addr = phys_pte_init(pte, address, - end, prot); + paddr_last = phys_pte_init(pte, paddr, + paddr_end, prot); spin_unlock(&init_mm.page_table_lock); continue; } @@ -420,7 +435,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, if (page_size_mask & (1 << PG_LEVEL_2M)) { if (!after_bootmem) pages++; - last_map_addr = next; + paddr_last = paddr_next; continue; } new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); @@ -430,42 +445,49 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, pages++; spin_lock(&init_mm.page_table_lock); set_pte((pte_t *)pmd, - pfn_pte((address & PMD_MASK) >> PAGE_SHIFT, + pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT, __pgprot(pgprot_val(prot) | _PAGE_PSE))); spin_unlock(&init_mm.page_table_lock); - last_map_addr = next; + paddr_last = paddr_next; continue; } pte = alloc_low_page(); - last_map_addr = phys_pte_init(pte, address, end, new_prot); + paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot); spin_lock(&init_mm.page_table_lock); pmd_populate_kernel(&init_mm, pmd, pte); spin_unlock(&init_mm.page_table_lock); } update_page_count(PG_LEVEL_2M, pages); - return last_map_addr; + return paddr_last; } +/* + * Create PUD level page table mapping for physical addresses. The virtual + * and physical address have to be aligned at this level. + * It returns the last physical address mapped. + */ static unsigned long __meminit -phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, - unsigned long page_size_mask) +phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end, + unsigned long page_size_mask) { - unsigned long pages = 0, next; - unsigned long last_map_addr = end; - int i = pud_index(addr); + unsigned long pages = 0, paddr_next; + unsigned long paddr_last = paddr_end; + int i = pud_index(paddr); - for (; i < PTRS_PER_PUD; i++, addr = next) { - pud_t *pud = pud_page + pud_index(addr); + for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) { + pud_t *pud = pud_page + pud_index(paddr); pmd_t *pmd; pgprot_t prot = PAGE_KERNEL; - next = (addr & PUD_MASK) + PUD_SIZE; - if (addr >= end) { + paddr_next = (paddr & PUD_MASK) + PUD_SIZE; + if (paddr >= paddr_end) { if (!after_bootmem && - !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) && - !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN)) + !e820_any_mapped(paddr & PUD_MASK, paddr_next, + E820_RAM) && + !e820_any_mapped(paddr & PUD_MASK, paddr_next, + E820_RESERVED_KERN)) set_pud(pud, __pud(0)); continue; } @@ -473,8 +495,10 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, if (pud_val(*pud)) { if (!pud_large(*pud)) { pmd = pmd_offset(pud, 0); - last_map_addr = phys_pmd_init(pmd, addr, end, - page_size_mask, prot); + paddr_last = phys_pmd_init(pmd, paddr, + paddr_end, + page_size_mask, + prot); __flush_tlb_all(); continue; } @@ -493,7 +517,7 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, if (page_size_mask & (1 << PG_LEVEL_1G)) { if (!after_bootmem) pages++; - last_map_addr = next; + paddr_last = paddr_next; continue; } prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); @@ -503,16 +527,16 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, pages++; spin_lock(&init_mm.page_table_lock); set_pte((pte_t *)pud, - pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT, + pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); spin_unlock(&init_mm.page_table_lock); - last_map_addr = next; + paddr_last = paddr_next; continue; } pmd = alloc_low_page(); - last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, - prot); + paddr_last = phys_pmd_init(pmd, paddr, paddr_end, + page_size_mask, prot); spin_lock(&init_mm.page_table_lock); pud_populate(&init_mm, pud, pmd); @@ -522,38 +546,44 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, update_page_count(PG_LEVEL_1G, pages); - return last_map_addr; + return paddr_last; } +/* + * Create page table mapping for the physical memory for specific physical + * addresses. The virtual and physical addresses have to be aligned on PUD level + * down. It returns the last physical address mapped. + */ unsigned long __meminit -kernel_physical_mapping_init(unsigned long start, - unsigned long end, +kernel_physical_mapping_init(unsigned long paddr_start, + unsigned long paddr_end, unsigned long page_size_mask) { bool pgd_changed = false; - unsigned long next, last_map_addr = end; - unsigned long addr; + unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last; - start = (unsigned long)__va(start); - end = (unsigned long)__va(end); - addr = start; + paddr_last = paddr_end; + vaddr = (unsigned long)__va(paddr_start); + vaddr_end = (unsigned long)__va(paddr_end); + vaddr_start = vaddr; - for (; start < end; start = next) { - pgd_t *pgd = pgd_offset_k(start); + for (; vaddr < vaddr_end; vaddr = vaddr_next) { + pgd_t *pgd = pgd_offset_k(vaddr); pud_t *pud; - next = (start & PGDIR_MASK) + PGDIR_SIZE; + vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE; if (pgd_val(*pgd)) { pud = (pud_t *)pgd_page_vaddr(*pgd); - last_map_addr = phys_pud_init(pud, __pa(start), - __pa(end), page_size_mask); + paddr_last = phys_pud_init(pud, __pa(vaddr), + __pa(vaddr_end), + page_size_mask); continue; } pud = alloc_low_page(); - last_map_addr = phys_pud_init(pud, __pa(start), __pa(end), - page_size_mask); + paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end), + page_size_mask); spin_lock(&init_mm.page_table_lock); pgd_populate(&init_mm, pgd, pud); @@ -562,11 +592,11 @@ kernel_physical_mapping_init(unsigned long start, } if (pgd_changed) - sync_global_pgds(addr, end - 1, 0); + sync_global_pgds(vaddr_start, vaddr_end - 1, 0); __flush_tlb_all(); - return last_map_addr; + return paddr_last; } #ifndef CONFIG_NUMA -- cgit v1.2.3