diff options
Diffstat (limited to 'arch/x86/kernel/efi_64.c')
| -rw-r--r-- | arch/x86/kernel/efi_64.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c new file mode 100644 index 000000000000..4b73992c1e11 --- /dev/null +++ b/arch/x86/kernel/efi_64.c @@ -0,0 +1,134 @@ +/* + * x86_64 specific EFI support functions + * Based on Extensible Firmware Interface Specification version 1.0 + * + * Copyright (C) 2005-2008 Intel Co. + * Fenghua Yu <fenghua.yu@intel.com> + * Bibo Mao <bibo.mao@intel.com> + * Chandramouli Narayanan <mouli@linux.intel.com> + * Huang Ying <ying.huang@intel.com> + * + * Code to convert EFI to E820 map has been implemented in elilo bootloader + * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table + * is setup appropriately for EFI runtime code. + * - mouli 06/14/2007. + * + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/bootmem.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/efi.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/reboot.h> + +#include <asm/setup.h> +#include <asm/page.h> +#include <asm/e820.h> +#include <asm/pgtable.h> +#include <asm/tlbflush.h> +#include <asm/proto.h> +#include <asm/efi.h> + +static pgd_t save_pgd __initdata; +static unsigned long efi_flags __initdata; + +static void __init early_mapping_set_exec(unsigned long start, + unsigned long end, + int executable) +{ + pte_t *kpte; + int level; + + while (start < end) { + kpte = lookup_address((unsigned long)__va(start), &level); + BUG_ON(!kpte); + if (executable) + set_pte(kpte, pte_mkexec(*kpte)); + else + set_pte(kpte, __pte((pte_val(*kpte) | _PAGE_NX) & \ + __supported_pte_mask)); + if (level == 4) + start = (start + PMD_SIZE) & PMD_MASK; + else + start = (start + PAGE_SIZE) & PAGE_MASK; + } +} + +static void __init early_runtime_code_mapping_set_exec(int executable) +{ + efi_memory_desc_t *md; + void *p; + + if (!(__supported_pte_mask & _PAGE_NX)) + return; + + /* Make EFI runtime service code area executable */ + for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { + md = p; + if (md->type == EFI_RUNTIME_SERVICES_CODE) { + unsigned long end; + end = md->phys_addr + (md->num_pages << PAGE_SHIFT); + early_mapping_set_exec(md->phys_addr, end, executable); + } + } +} + +void __init efi_call_phys_prelog(void) +{ + unsigned long vaddress; + + local_irq_save(efi_flags); + early_runtime_code_mapping_set_exec(1); + vaddress = (unsigned long)__va(0x0UL); + save_pgd = *pgd_offset_k(0x0UL); + set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress)); + __flush_tlb_all(); +} + +void __init efi_call_phys_epilog(void) +{ + /* + * After the lock is released, the original page table is restored. + */ + set_pgd(pgd_offset_k(0x0UL), save_pgd); + early_runtime_code_mapping_set_exec(0); + __flush_tlb_all(); + local_irq_restore(efi_flags); +} + +void __init efi_reserve_bootmem(void) +{ + reserve_bootmem_generic((unsigned long)memmap.phys_map, + memmap.nr_map * memmap.desc_size); +} + +void __iomem * __init efi_ioremap(unsigned long offset, + unsigned long size) +{ + static unsigned pages_mapped; + unsigned long last_addr; + unsigned i, pages; + + last_addr = offset + size - 1; + offset &= PAGE_MASK; + pages = (PAGE_ALIGN(last_addr) - offset) >> PAGE_SHIFT; + if (pages_mapped + pages > MAX_EFI_IO_PAGES) + return NULL; + + for (i = 0; i < pages; i++) { + __set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped, + offset, PAGE_KERNEL_EXEC_NOCACHE); + offset += PAGE_SIZE; + pages_mapped++; + } + + return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \ + (pages_mapped - pages)); +} |