diff options
Diffstat (limited to 'arch/x86/mm/init_64.c')
| -rw-r--r-- | arch/x86/mm/init_64.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index a4a9cccdd4f..a02a14f0f32 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -171,6 +171,34 @@ set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot) __flush_tlb_one(vaddr); } +/* + * The head.S code sets up the kernel high mapping: + * + * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) + * + * phys_addr holds the negative offset to the kernel, which is added + * to the compile time generated pmds. This results in invalid pmds up + * to the point where we hit the physaddr 0 mapping. + * + * We limit the mappings to the region from _text to _end. _end is + * rounded up to the 2MB boundary. This catches the invalid pmds as + * well, as they are located before _text: + */ +void __init cleanup_highmap(void) +{ + unsigned long vaddr = __START_KERNEL_map; + unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1; + pmd_t *pmd = level2_kernel_pgt; + pmd_t *last_pmd = pmd + PTRS_PER_PMD; + + for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) { + if (!pmd_present(*pmd)) + continue; + if (vaddr < (unsigned long) _text || vaddr > end) + set_pmd(pmd, __pmd(0)); + } +} + /* NOTE: this is meant to be run only at boot */ void __init __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) @@ -488,14 +516,6 @@ void __init mem_init(void) /* clear_bss() already clear the empty_zero_page */ - /* temporary debugging - double check it's true: */ - { - int i; - - for (i = 0; i < 1024; i++) - WARN_ON_ONCE(empty_zero_page[i]); - } - reservedpages = 0; /* this will put all low memory onto the freelists */ |