linux/arch/x86/kernel/efi_64.c

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/*
* 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>
#include <asm/cacheflush.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)
{
unsigned long num_pages;
start &= PMD_MASK;
end = (end + PMD_SIZE - 1) & PMD_MASK;
num_pages = (end - start) >> PAGE_SHIFT;
if (executable)
set_memory_x((unsigned long)__va(start), num_pages);
else
set_memory_nx((unsigned long)__va(start), num_pages);
}
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 << EFI_PAGE_SHIFT);
early_mapping_set_exec(md->phys_addr, end, executable);
}
}
}
void __init efi_call_phys_prelog(void)
{
unsigned long vaddress;
early_runtime_code_mapping_set_exec(1);
local_irq_save(efi_flags);
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);
__flush_tlb_all();
local_irq_restore(efi_flags);
early_runtime_code_mapping_set_exec(0);
}
void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size)
{
static unsigned pages_mapped __initdata;
unsigned i, pages;
unsigned long offset;
pages = PFN_UP(phys_addr + size) - PFN_DOWN(phys_addr);
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
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)) + offset;
}