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Commit 45486f81 authored by Keith Owens's avatar Keith Owens Committed by Linus Torvalds
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[PATCH] x86_64: Standardize i386/x86_64 handling of NMI_VECTOR 



x86_64 and i386 behave inconsistently when sending an IPI on vector 2
(NMI_VECTOR).  Make both behave the same, so IPI 2 is sent as NMI.

The crash code was abusing send_IPI_allbutself() by passing a code
instead of a vector, it only worked because crash knew about the
internal code of send_IPI_allbutself().  Change crash to use NMI_VECTOR
instead, and remove the comment about how crash was abusing the function.

This patch is a pre-requisite for fixing the problem where sending an
IPI as NMI would reboot some Dell Xeon systems.  I cannot fix that
problem while crash continus to abuse send_IPI_allbutself().

It also removes the inconsistency between i386 and x86_64 for
NMI_VECTOR.  That will simplify all the RAS code that needs to bring
all the cpus to a clean stop, even when one or more cpus are spinning
disabled.

Signed-off-by: default avatarKeith Owens <kaos@sgi.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9c63f873

arch/i386/kernel/crash.c

+1 −6
Original line number Diff line number Diff line
@@ -120,14 +120,9 @@ static int crash_nmi_callback(struct pt_regs *regs, int cpu) 
	return 1;

}



/*

 * By using the NMI code instead of a vector we just sneak thru the

 * word generator coming out with just what we want.  AND it does

 * not matter if clustered_apic_mode is set or not.

 */

static void smp_send_nmi_allbutself(void)

{

	send_IPI_allbutself(APIC_DM_NMI);

	send_IPI_allbutself(NMI_VECTOR);

}



static void nmi_shootdown_cpus(void)

arch/i386/kernel/smp.c

+11 −1
Original line number Diff line number Diff line
@@ -114,7 +114,17 @@ DEFINE_PER_CPU(struct tlb_state, cpu_tlbstate) ____cacheline_aligned = { &init_m 


static inline int __prepare_ICR (unsigned int shortcut, int vector)

{

	return APIC_DM_FIXED | shortcut | vector | APIC_DEST_LOGICAL;

	unsigned int icr = shortcut | APIC_DEST_LOGICAL;



	switch (vector) {

	default:

		icr |= APIC_DM_FIXED | vector;

		break;

	case NMI_VECTOR:

		icr |= APIC_DM_NMI;

		break;

	}

	return icr;

}



static inline int __prepare_ICR2 (unsigned int mask)

arch/x86_64/kernel/crash.c

+1 −1
Original line number Diff line number Diff line
@@ -118,7 +118,7 @@ static int crash_nmi_callback(struct pt_regs *regs, int cpu) 


static void smp_send_nmi_allbutself(void)

{

	send_IPI_allbutself(APIC_DM_NMI);

	send_IPI_allbutself(NMI_VECTOR);

}



/*

include/asm-i386/hw_irq.h

+2 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 


struct hw_interrupt_type;



#define NMI_VECTOR		0x02



/*

 * Various low-level irq details needed by irq.c, process.c,

 * time.c, io_apic.c and smp.c