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Commit 245067d1 authored by Zachary Amsden's avatar Zachary Amsden Committed by Linus Torvalds
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[PATCH] i386: cleanup serialize msr 



i386 arch cleanup.  Introduce the serialize macro to serialize processor
state.  Why the microcode update needs it I am not quite sure, since wrmsr()
is already a serializing instruction, but it is a microcode update, so I will
keep the semantic the same, since this could be a timing workaround.  As far
as I can tell, this has always been there since the original microcode update
source.

Signed-off-by: default avatarZachary Amsden <zach@vmware.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 4bb0d3ec

arch/i386/kernel/microcode.c

+5 −2
Original line number Diff line number Diff line
@@ -164,7 +164,8 @@ static void collect_cpu_info (void *unused) 
	}



	wrmsr(MSR_IA32_UCODE_REV, 0, 0);

	__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");

	/* see notes above for revision 1.07.  Apparent chip bug */

	serialize_cpu();

	/* get the current revision from MSR 0x8B */

	rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);

	pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
@@ -377,7 +378,9 @@ static void do_update_one (void * unused) 
		(unsigned long) uci->mc->bits >> 16 >> 16);

	wrmsr(MSR_IA32_UCODE_REV, 0, 0);



	__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");

	/* see notes above for revision 1.07.  Apparent chip bug */

	serialize_cpu();



	/* get the current revision from MSR 0x8B */

	rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);

include/asm-i386/processor.h

+5 −0
Original line number Diff line number Diff line
@@ -277,6 +277,11 @@ static inline void clear_in_cr4 (unsigned long mask) 
	outb((data), 0x23); \

} while (0)



static inline void serialize_cpu(void)

{

	 __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");

}



static inline void __monitor(const void *eax, unsigned long ecx,

		unsigned long edx)

{

include/asm-x86_64/processor.h

+5 −0
Original line number Diff line number Diff line
@@ -437,6 +437,11 @@ static inline void prefetchw(void *x) 
	outb((data), 0x23); \

} while (0)



static inline void serialize_cpu(void)

{

	__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");

}



static inline void __monitor(const void *eax, unsigned long ecx,

		unsigned long edx)

{