135 lines
3.3 KiB
C
135 lines
3.3 KiB
C
/*
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* x86_64 specific EFI support functions
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* Based on Extensible Firmware Interface Specification version 1.0
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*
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* Copyright (C) 2005-2008 Intel Co.
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* Fenghua Yu <fenghua.yu@intel.com>
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* Bibo Mao <bibo.mao@intel.com>
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* Chandramouli Narayanan <mouli@linux.intel.com>
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* Huang Ying <ying.huang@intel.com>
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*
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* Code to convert EFI to E820 map has been implemented in elilo bootloader
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* based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
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* is setup appropriately for EFI runtime code.
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* - mouli 06/14/2007.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/types.h>
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#include <linux/spinlock.h>
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#include <linux/bootmem.h>
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#include <linux/ioport.h>
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#include <linux/module.h>
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#include <linux/efi.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#include <linux/reboot.h>
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#include <asm/setup.h>
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#include <asm/page.h>
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#include <asm/e820.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/proto.h>
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#include <asm/efi.h>
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static pgd_t save_pgd __initdata;
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static unsigned long efi_flags __initdata;
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static void __init early_mapping_set_exec(unsigned long start,
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unsigned long end,
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int executable)
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{
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pte_t *kpte;
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unsigned int level;
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while (start < end) {
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kpte = lookup_address((unsigned long)__va(start), &level);
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BUG_ON(!kpte);
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if (executable)
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set_pte(kpte, pte_mkexec(*kpte));
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else
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set_pte(kpte, __pte((pte_val(*kpte) | _PAGE_NX) & \
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__supported_pte_mask));
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if (level == PG_LEVEL_4K)
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start = (start + PAGE_SIZE) & PAGE_MASK;
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else
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start = (start + PMD_SIZE) & PMD_MASK;
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}
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}
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static void __init early_runtime_code_mapping_set_exec(int executable)
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{
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efi_memory_desc_t *md;
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void *p;
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if (!(__supported_pte_mask & _PAGE_NX))
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return;
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/* Make EFI runtime service code area executable */
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for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
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md = p;
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if (md->type == EFI_RUNTIME_SERVICES_CODE) {
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unsigned long end;
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end = md->phys_addr + (md->num_pages << PAGE_SHIFT);
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early_mapping_set_exec(md->phys_addr, end, executable);
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}
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}
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}
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void __init efi_call_phys_prelog(void)
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{
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unsigned long vaddress;
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local_irq_save(efi_flags);
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early_runtime_code_mapping_set_exec(1);
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vaddress = (unsigned long)__va(0x0UL);
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save_pgd = *pgd_offset_k(0x0UL);
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set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress));
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__flush_tlb_all();
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}
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void __init efi_call_phys_epilog(void)
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{
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/*
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* After the lock is released, the original page table is restored.
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*/
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set_pgd(pgd_offset_k(0x0UL), save_pgd);
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early_runtime_code_mapping_set_exec(0);
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__flush_tlb_all();
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local_irq_restore(efi_flags);
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}
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void __init efi_reserve_bootmem(void)
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{
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reserve_bootmem_generic((unsigned long)memmap.phys_map,
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memmap.nr_map * memmap.desc_size);
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}
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void __iomem * __init efi_ioremap(unsigned long phys_addr, unsigned long size)
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{
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static unsigned pages_mapped;
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unsigned i, pages;
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/* phys_addr and size must be page aligned */
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if ((phys_addr & ~PAGE_MASK) || (size & ~PAGE_MASK))
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return NULL;
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pages = size >> PAGE_SHIFT;
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if (pages_mapped + pages > MAX_EFI_IO_PAGES)
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return NULL;
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for (i = 0; i < pages; i++) {
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__set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
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phys_addr, PAGE_KERNEL);
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phys_addr += PAGE_SIZE;
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pages_mapped++;
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}
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return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
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(pages_mapped - pages));
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}
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