/* * 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; unsigned 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 == PG_LEVEL_4K) start = (start + PAGE_SIZE) & PAGE_MASK; else start = (start + PMD_SIZE) & PMD_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 phys_addr, unsigned long size) { static unsigned pages_mapped; unsigned i, pages; /* phys_addr and size must be page aligned */ if ((phys_addr & ~PAGE_MASK) || (size & ~PAGE_MASK)) return NULL; pages = size >> 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, phys_addr, PAGE_KERNEL); phys_addr += PAGE_SIZE; pages_mapped++; } return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \ (pages_mapped - pages)); }