diff options
| -rw-r--r-- | arch/x86/mm/init_32.c | 65 | ||||
| -rw-r--r-- | arch/x86/mm/init_64.c | 99 |
2 files changed, 144 insertions, 20 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index d37f29376b0..9b5f7d7049d 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -194,11 +194,30 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base, pgd_t *pgd; pmd_t *pmd; pte_t *pte; - unsigned pages_2m = 0, pages_4k = 0; + unsigned pages_2m, pages_4k; + int mapping_iter; + + /* + * First iteration will setup identity mapping using large/small pages + * based on use_pse, with other attributes same as set by + * the early code in head_32.S + * + * Second iteration will setup the appropriate attributes (NX, GLOBAL..) + * as desired for the kernel identity mapping. + * + * This two pass mechanism conforms to the TLB app note which says: + * + * "Software should not write to a paging-structure entry in a way + * that would change, for any linear address, both the page size + * and either the page frame or attributes." + */ + mapping_iter = 1; if (!cpu_has_pse) use_pse = 0; +repeat: + pages_2m = pages_4k = 0; pfn = start_pfn; pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); pgd = pgd_base + pgd_idx; @@ -224,6 +243,13 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base, if (use_pse) { unsigned int addr2; pgprot_t prot = PAGE_KERNEL_LARGE; + /* + * first pass will use the same initial + * identity mapping attribute + _PAGE_PSE. + */ + pgprot_t init_prot = + __pgprot(PTE_IDENT_ATTR | + _PAGE_PSE); addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + PAGE_OFFSET + PAGE_SIZE-1; @@ -233,7 +259,10 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base, prot = PAGE_KERNEL_LARGE_EXEC; pages_2m++; - set_pmd(pmd, pfn_pmd(pfn, prot)); + if (mapping_iter == 1) + set_pmd(pmd, pfn_pmd(pfn, init_prot)); + else + set_pmd(pmd, pfn_pmd(pfn, prot)); pfn += PTRS_PER_PTE; continue; @@ -245,17 +274,43 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base, for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { pgprot_t prot = PAGE_KERNEL; + /* + * first pass will use the same initial + * identity mapping attribute. + */ + pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); if (is_kernel_text(addr)) prot = PAGE_KERNEL_EXEC; pages_4k++; - set_pte(pte, pfn_pte(pfn, prot)); + if (mapping_iter == 1) + set_pte(pte, pfn_pte(pfn, init_prot)); + else + set_pte(pte, pfn_pte(pfn, prot)); } } } - update_page_count(PG_LEVEL_2M, pages_2m); - update_page_count(PG_LEVEL_4K, pages_4k); + if (mapping_iter == 1) { + /* + * update direct mapping page count only in the first + * iteration. + */ + update_page_count(PG_LEVEL_2M, pages_2m); + update_page_count(PG_LEVEL_4K, pages_4k); + + /* + * local global flush tlb, which will flush the previous + * mappings present in both small and large page TLB's. + */ + __flush_tlb_all(); + + /* + * Second iteration will set the actual desired PTE attributes. + */ + mapping_iter = 2; + goto repeat; + } } /* diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index d3746efb060..1ba945eb628 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -270,6 +270,8 @@ static __ref void unmap_low_page(void *adr) early_iounmap(adr, PAGE_SIZE); } +static int physical_mapping_iter; + static unsigned long __meminit phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end) { @@ -290,16 +292,19 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end) } if (pte_val(*pte)) - continue; + goto repeat_set_pte; if (0) printk(" pte=%p addr=%lx pte=%016lx\n", pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); + pages++; +repeat_set_pte: set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL)); last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; - pages++; } - update_page_count(PG_LEVEL_4K, pages); + + if (physical_mapping_iter == 1) + update_page_count(PG_LEVEL_4K, pages); return last_map_addr; } @@ -318,7 +323,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, { unsigned long pages = 0; unsigned long last_map_addr = end; - unsigned long start = address; int i = pmd_index(address); @@ -341,15 +345,14 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, last_map_addr = phys_pte_update(pmd, address, end); spin_unlock(&init_mm.page_table_lock); + continue; } - /* Count entries we're using from level2_ident_pgt */ - if (start == 0) - pages++; - continue; + goto repeat_set_pte; } if (page_size_mask & (1<<PG_LEVEL_2M)) { pages++; +repeat_set_pte: spin_lock(&init_mm.page_table_lock); set_pte((pte_t *)pmd, pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); @@ -366,7 +369,8 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); spin_unlock(&init_mm.page_table_lock); } - update_page_count(PG_LEVEL_2M, pages); + if (physical_mapping_iter == 1) + update_page_count(PG_LEVEL_2M, pages); return last_map_addr; } @@ -405,14 +409,18 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, } if (pud_val(*pud)) { - if (!pud_large(*pud)) + if (!pud_large(*pud)) { last_map_addr = phys_pmd_update(pud, addr, end, page_size_mask); - continue; + continue; + } + + goto repeat_set_pte; } if (page_size_mask & (1<<PG_LEVEL_1G)) { pages++; +repeat_set_pte: spin_lock(&init_mm.page_table_lock); set_pte((pte_t *)pud, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); @@ -430,7 +438,9 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, spin_unlock(&init_mm.page_table_lock); } __flush_tlb_all(); - update_page_count(PG_LEVEL_1G, pages); + + if (physical_mapping_iter == 1) + update_page_count(PG_LEVEL_1G, pages); return last_map_addr; } @@ -494,15 +504,54 @@ static void __init init_gbpages(void) direct_gbpages = 0; } +static int is_kernel(unsigned long pfn) +{ + unsigned long pg_addresss = pfn << PAGE_SHIFT; + + if (pg_addresss >= (unsigned long) __pa(_text) && + pg_addresss <= (unsigned long) __pa(_end)) + return 1; + + return 0; +} + static unsigned long __init kernel_physical_mapping_init(unsigned long start, unsigned long end, unsigned long page_size_mask) { - unsigned long next, last_map_addr = end; + unsigned long next, last_map_addr; + u64 cached_supported_pte_mask = __supported_pte_mask; + unsigned long cache_start = start; + unsigned long cache_end = end; + + /* + * First iteration will setup identity mapping using large/small pages + * based on page_size_mask, with other attributes same as set by + * the early code in head_64.S + * + * Second iteration will setup the appropriate attributes + * as desired for the kernel identity mapping. + * + * This two pass mechanism conforms to the TLB app note which says: + * + * "Software should not write to a paging-structure entry in a way + * that would change, for any linear address, both the page size + * and either the page frame or attributes." + * + * For now, only difference between very early PTE attributes used in + * head_64.S and here is _PAGE_NX. + */ + BUILD_BUG_ON((__PAGE_KERNEL_LARGE & ~__PAGE_KERNEL_IDENT_LARGE_EXEC) + != _PAGE_NX); + __supported_pte_mask &= ~(_PAGE_NX); + physical_mapping_iter = 1; - start = (unsigned long)__va(start); - end = (unsigned long)__va(end); +repeat: + last_map_addr = cache_end; + + start = (unsigned long)__va(cache_start); + end = (unsigned long)__va(cache_end); for (; start < end; start = next) { pgd_t *pgd = pgd_offset_k(start); @@ -514,11 +563,21 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start, next = end; if (pgd_val(*pgd)) { + /* + * Static identity mappings will be overwritten + * with run-time mappings. For example, this allows + * the static 0-1GB identity mapping to be mapped + * non-executable with this. + */ + if (is_kernel(pte_pfn(*((pte_t *) pgd)))) + goto realloc; + last_map_addr = phys_pud_update(pgd, __pa(start), __pa(end), page_size_mask); continue; } +realloc: pud = alloc_low_page(&pud_phys); last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), page_size_mask); @@ -528,6 +587,16 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start, pgd_populate(&init_mm, pgd, __va(pud_phys)); spin_unlock(&init_mm.page_table_lock); } + __flush_tlb_all(); + + if (physical_mapping_iter == 1) { + physical_mapping_iter = 2; + /* + * Second iteration will set the actual desired PTE attributes. + */ + __supported_pte_mask = cached_supported_pte_mask; + goto repeat; + } return last_map_addr; } |