diff options
Diffstat (limited to 'arch/arm64/mm/mmu.c')
-rw-r--r-- | arch/arm64/mm/mmu.c | 89 |
1 files changed, 46 insertions, 43 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 4cd4862845cd..5b1184c369d5 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -22,6 +22,8 @@ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/init.h> +#include <linux/ioport.h> +#include <linux/kexec.h> #include <linux/libfdt.h> #include <linux/mman.h> #include <linux/nodemask.h> @@ -317,56 +319,32 @@ static void create_mapping_late(phys_addr_t phys, unsigned long virt, NULL, !debug_pagealloc_enabled()); } -static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end) +static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, + phys_addr_t end, pgprot_t prot, + bool allow_block_mappings) +{ + __create_pgd_mapping(pgd, start, __phys_to_virt(start), end - start, + prot, early_pgtable_alloc, allow_block_mappings); +} + +static void __init map_mem(pgd_t *pgd) { unsigned long kernel_start = __pa(_text); unsigned long kernel_end = __pa(__init_begin); + struct memblock_region *reg; /* * Take care not to create a writable alias for the * read-only text and rodata sections of the kernel image. + * So temporarily mark them as NOMAP to skip mappings in + * the following for-loop */ - - /* No overlap with the kernel text/rodata */ - if (end < kernel_start || start >= kernel_end) { - __create_pgd_mapping(pgd, start, __phys_to_virt(start), - end - start, PAGE_KERNEL, - early_pgtable_alloc, - !debug_pagealloc_enabled()); - return; - } - - /* - * This block overlaps the kernel text/rodata mappings. - * Map the portion(s) which don't overlap. - */ - if (start < kernel_start) - __create_pgd_mapping(pgd, start, - __phys_to_virt(start), - kernel_start - start, PAGE_KERNEL, - early_pgtable_alloc, - !debug_pagealloc_enabled()); - if (kernel_end < end) - __create_pgd_mapping(pgd, kernel_end, - __phys_to_virt(kernel_end), - end - kernel_end, PAGE_KERNEL, - early_pgtable_alloc, - !debug_pagealloc_enabled()); - - /* - * Map the linear alias of the [_text, __init_begin) interval as - * read-only/non-executable. This makes the contents of the - * region accessible to subsystems such as hibernate, but - * protects it from inadvertent modification or execution. - */ - __create_pgd_mapping(pgd, kernel_start, __phys_to_virt(kernel_start), - kernel_end - kernel_start, PAGE_KERNEL_RO, - early_pgtable_alloc, !debug_pagealloc_enabled()); -} - -static void __init map_mem(pgd_t *pgd) -{ - struct memblock_region *reg; + memblock_mark_nomap(kernel_start, kernel_end - kernel_start); +#ifdef CONFIG_KEXEC_CORE + if (crashk_res.end) + memblock_mark_nomap(crashk_res.start, + resource_size(&crashk_res)); +#endif /* map all the memory banks */ for_each_memblock(memory, reg) { @@ -378,8 +356,33 @@ static void __init map_mem(pgd_t *pgd) if (memblock_is_nomap(reg)) continue; - __map_memblock(pgd, start, end); + __map_memblock(pgd, start, end, + PAGE_KERNEL, !debug_pagealloc_enabled()); } + + /* + * Map the linear alias of the [_text, __init_begin) interval as + * read-only/non-executable. This makes the contents of the + * region accessible to subsystems such as hibernate, but + * protects it from inadvertent modification or execution. + */ + __map_memblock(pgd, kernel_start, kernel_end, + PAGE_KERNEL_RO, !debug_pagealloc_enabled()); + memblock_clear_nomap(kernel_start, kernel_end - kernel_start); + +#ifdef CONFIG_KEXEC_CORE + /* + * Use page-level mappings here so that we can shrink the region + * in page granularity and put back unused memory to buddy system + * through /sys/kernel/kexec_crash_size interface. + */ + if (crashk_res.end) { + __map_memblock(pgd, crashk_res.start, crashk_res.end + 1, + PAGE_KERNEL, false); + memblock_clear_nomap(crashk_res.start, + resource_size(&crashk_res)); + } +#endif } void mark_rodata_ro(void) |