diff options
Diffstat (limited to 'arch/x86/mm/init_32.c')
| -rw-r--r-- | arch/x86/mm/init_32.c | 72 |
1 files changed, 27 insertions, 45 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index d1bc040..54aba3c 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -46,6 +46,7 @@ #include <asm/pgalloc.h> #include <asm/sections.h> #include <asm/paravirt.h> +#include <asm/setup.h> unsigned int __VMALLOC_RESERVE = 128 << 20; @@ -328,44 +329,38 @@ pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC; void __init native_pagetable_setup_start(pgd_t *base) { -#ifdef CONFIG_X86_PAE - int i; + unsigned long pfn, va; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; /* - * Init entries of the first-level page table to the - * zero page, if they haven't already been set up. - * - * In a normal native boot, we'll be running on a - * pagetable rooted in swapper_pg_dir, but not in PAE - * mode, so this will end up clobbering the mappings - * for the lower 24Mbytes of the address space, - * without affecting the kernel address space. + * Remove any mappings which extend past the end of physical + * memory from the boot time page table: */ - for (i = 0; i < USER_PTRS_PER_PGD; i++) - set_pgd(&base[i], - __pgd(__pa(empty_zero_page) | _PAGE_PRESENT)); - - /* Make sure kernel address space is empty so that a pagetable - will be allocated for it. */ - memset(&base[USER_PTRS_PER_PGD], 0, - KERNEL_PGD_PTRS * sizeof(pgd_t)); -#else + for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { + va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); + pgd = base + pgd_index(va); + if (!pgd_present(*pgd)) + break; + + pud = pud_offset(pgd, va); + pmd = pmd_offset(pud, va); + if (!pmd_present(*pmd)) + break; + + pte = pte_offset_kernel(pmd, va); + if (!pte_present(*pte)) + break; + + pte_clear(NULL, va, pte); + } paravirt_alloc_pd(&init_mm, __pa(base) >> PAGE_SHIFT); -#endif } void __init native_pagetable_setup_done(pgd_t *base) { -#ifdef CONFIG_X86_PAE - /* - * Add low memory identity-mappings - SMP needs it when - * starting up on an AP from real-mode. In the non-PAE - * case we already have these mappings through head.S. - * All user-space mappings are explicitly cleared after - * SMP startup. - */ - set_pgd(&base[0], base[USER_PTRS_PER_PGD]); -#endif } /* @@ -374,9 +369,8 @@ void __init native_pagetable_setup_done(pgd_t *base) * the boot process. * * If we're booting on native hardware, this will be a pagetable - * constructed in arch/i386/kernel/head.S, and not running in PAE mode - * (even if we'll end up running in PAE). The root of the pagetable - * will be swapper_pg_dir. + * constructed in arch/x86/kernel/head_32.S. The root of the + * pagetable will be swapper_pg_dir. * * If we're booting paravirtualized under a hypervisor, then there are * more options: we may already be running PAE, and the pagetable may @@ -537,14 +531,6 @@ void __init paging_init(void) load_cr3(swapper_pg_dir); -#ifdef CONFIG_X86_PAE - /* - * We will bail out later - printk doesn't work right now so - * the user would just see a hanging kernel. - */ - if (cpu_has_pae) - set_in_cr4(X86_CR4_PAE); -#endif __flush_tlb_all(); kmap_init(); @@ -675,10 +661,6 @@ void __init mem_init(void) BUG_ON((unsigned long)high_memory > VMALLOC_START); #endif /* double-sanity-check paranoia */ -#ifdef CONFIG_X86_PAE - if (!cpu_has_pae) - panic("cannot execute a PAE-enabled kernel on a PAE-less CPU!"); -#endif if (boot_cpu_data.wp_works_ok < 0) test_wp_bit(); |