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744937b0b1
Currently x86-64 efi_call_phys_prolog() saves into a global variable (save_pgd), and efi_call_phys_epilog() restores the kernel pagetables from that global variable. Change this to a cleaner save/restore pattern where the saving function returns the saved object and the restore function restores that. Apply the same concept to the 32-bit code as well. Plus this approach, as an added bonus, allows us to express the !efi_enabled(EFI_OLD_MEMMAP) situation in a clean fashion as well, via a 'NULL' return value. Cc: Tapasweni Pathak <tapaswenipathak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
/*
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* Extensible Firmware Interface
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*
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* Based on Extensible Firmware Interface Specification version 1.0
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*
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* Copyright (C) 1999 VA Linux Systems
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* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
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* Copyright (C) 1999-2002 Hewlett-Packard Co.
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* David Mosberger-Tang <davidm@hpl.hp.com>
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* Stephane Eranian <eranian@hpl.hp.com>
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*
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* All EFI Runtime Services are not implemented yet as EFI only
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* supports physical mode addressing on SoftSDV. This is to be fixed
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* in a future version. --drummond 1999-07-20
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*
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* Implemented EFI runtime services and virtual mode calls. --davidm
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*
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* Goutham Rao: <goutham.rao@intel.com>
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* Skip non-WB memory and ignore empty memory ranges.
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/ioport.h>
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#include <linux/efi.h>
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#include <asm/io.h>
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#include <asm/desc.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/efi.h>
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/*
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* To make EFI call EFI runtime service in physical addressing mode we need
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* prolog/epilog before/after the invocation to claim the EFI runtime service
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* handler exclusively and to duplicate a memory mapping in low memory space,
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* say 0 - 3G.
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*/
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void efi_sync_low_kernel_mappings(void) {}
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void __init efi_dump_pagetable(void) {}
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int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
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{
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return 0;
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}
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void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
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{
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}
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void __init efi_map_region(efi_memory_desc_t *md)
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{
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old_map_region(md);
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}
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void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
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void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
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pgd_t * __init efi_call_phys_prolog(void)
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{
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struct desc_ptr gdt_descr;
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pgd_t *save_pgd;
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/* Current pgd is swapper_pg_dir, we'll restore it later: */
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save_pgd = swapper_pg_dir;
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load_cr3(initial_page_table);
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__flush_tlb_all();
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gdt_descr.address = __pa(get_cpu_gdt_table(0));
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gdt_descr.size = GDT_SIZE - 1;
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load_gdt(&gdt_descr);
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return save_pgd;
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}
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void __init efi_call_phys_epilog(pgd_t *save_pgd)
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{
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struct desc_ptr gdt_descr;
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gdt_descr.address = (unsigned long)get_cpu_gdt_table(0);
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gdt_descr.size = GDT_SIZE - 1;
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load_gdt(&gdt_descr);
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load_cr3(save_pgd);
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__flush_tlb_all();
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}
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void __init efi_runtime_mkexec(void)
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{
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if (__supported_pte_mask & _PAGE_NX)
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runtime_code_page_mkexec();
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}
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