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216705d272
Fedora reports that mem_init()'s zap_low_mappings(), extended to SMP in
61165d7a03 x86: fix app crashes after SMP
resume causes 32-bit Intel Mac machines to reboot very early when
booting with EFI.
The EFI code appears to manage low mappings for itself when needed; but
like many before it, confuses PSE with PAE. So it has only been mapping
half the space it needed when PSE but not PAE. This remained unnoticed
until we moved the SMP zap_low_mappings() before
efi_enter_virtual_mode(). Presumably could have been noticed years ago
if anyone ran a UP kernel on such machines?
Reported-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Glauber Costa <gcosta@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Peter Jones <pjones@redhat.com>
113 lines
2.9 KiB
C
113 lines
2.9 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/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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* prelog/epilog before/after the invocation to disable interrupt, to
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* claim EFI runtime service handler exclusively and to duplicate a memory in
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* low memory space say 0 - 3G.
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*/
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static unsigned long efi_rt_eflags;
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static pgd_t efi_bak_pg_dir_pointer[2];
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void efi_call_phys_prelog(void)
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{
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unsigned long cr4;
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unsigned long temp;
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struct desc_ptr gdt_descr;
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local_irq_save(efi_rt_eflags);
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/*
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* If I don't have PAE, I should just duplicate two entries in page
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* directory. If I have PAE, I just need to duplicate one entry in
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* page directory.
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*/
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cr4 = read_cr4();
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if (cr4 & X86_CR4_PAE) {
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efi_bak_pg_dir_pointer[0].pgd =
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swapper_pg_dir[pgd_index(0)].pgd;
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swapper_pg_dir[0].pgd =
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swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
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} else {
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efi_bak_pg_dir_pointer[0].pgd =
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swapper_pg_dir[pgd_index(0)].pgd;
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efi_bak_pg_dir_pointer[1].pgd =
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swapper_pg_dir[pgd_index(0x400000)].pgd;
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swapper_pg_dir[pgd_index(0)].pgd =
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swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
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temp = PAGE_OFFSET + 0x400000;
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swapper_pg_dir[pgd_index(0x400000)].pgd =
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swapper_pg_dir[pgd_index(temp)].pgd;
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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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__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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}
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void efi_call_phys_epilog(void)
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{
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unsigned long cr4;
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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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cr4 = read_cr4();
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if (cr4 & X86_CR4_PAE) {
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swapper_pg_dir[pgd_index(0)].pgd =
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efi_bak_pg_dir_pointer[0].pgd;
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} else {
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swapper_pg_dir[pgd_index(0)].pgd =
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efi_bak_pg_dir_pointer[0].pgd;
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swapper_pg_dir[pgd_index(0x400000)].pgd =
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efi_bak_pg_dir_pointer[1].pgd;
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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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__flush_tlb_all();
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local_irq_restore(efi_rt_eflags);
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}
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