forked from luck/tmp_suning_uos_patched
299c56966a
A customer of ours, complained that when setting the reset vector back to 0, it trashed other data and hung their box. They noticed when only 4 bytes were set to 0 instead of 8, everything worked correctly. Mathew pointed out: | | We're supposed to be resetting trampoline_phys_low and | trampoline_phys_high here, which are two 16-bit values. | Writing 64 bits is definitely going to overwrite space | that we're not supposed to be touching. | So limit the area modified to u32. Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: Matthew Garrett <mjg@redhat.com> Cc: <stable@kernel.org> LKML-Reference: <1297139100-424-1-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
61 lines
1.3 KiB
C
61 lines
1.3 KiB
C
/* two abstractions specific to kernel/smpboot.c, mainly to cater to visws
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* which needs to alter them. */
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static inline void smpboot_clear_io_apic_irqs(void)
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{
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#ifdef CONFIG_X86_IO_APIC
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io_apic_irqs = 0;
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#endif
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}
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static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
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{
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CMOS_WRITE(0xa, 0xf);
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local_flush_tlb();
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pr_debug("1.\n");
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*((volatile unsigned short *)phys_to_virt(apic->trampoline_phys_high)) =
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start_eip >> 4;
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pr_debug("2.\n");
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*((volatile unsigned short *)phys_to_virt(apic->trampoline_phys_low)) =
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start_eip & 0xf;
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pr_debug("3.\n");
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}
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static inline void smpboot_restore_warm_reset_vector(void)
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{
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/*
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* Install writable page 0 entry to set BIOS data area.
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*/
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local_flush_tlb();
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/*
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* Paranoid: Set warm reset code and vector here back
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* to default values.
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*/
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CMOS_WRITE(0, 0xf);
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*((volatile u32 *)phys_to_virt(apic->trampoline_phys_low)) = 0;
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}
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static inline void __init smpboot_setup_io_apic(void)
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{
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#ifdef CONFIG_X86_IO_APIC
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/*
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* Here we can be sure that there is an IO-APIC in the system. Let's
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* go and set it up:
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*/
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if (!skip_ioapic_setup && nr_ioapics)
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setup_IO_APIC();
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else {
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nr_ioapics = 0;
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}
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#endif
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}
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static inline void smpboot_clear_io_apic(void)
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{
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#ifdef CONFIG_X86_IO_APIC
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nr_ioapics = 0;
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#endif
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}
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