From 3b08606dc2991bcdab14139efd9ed9d492f5f901 Mon Sep 17 00:00:00 2001 From: keith mannthey Date: Fri, 29 Sep 2006 01:58:46 -0700 Subject: [PATCH] convert i386 Summit subarch to use SRAT info for apicid_to_node calls Convert the i386 summit subarch apicid_to_node to use node information provided by the SRAT. It was discussed a little on LKML a few weeks ago and was seen as an acceptable fix. The current way of obtaining the nodeid static inline int apicid_to_node(int logical_apicid) { return logical_apicid >> 5; } is just not correct for all summit systems/bios. Assuming the apicid matches the Linux node number require a leap of faith that the bios mapped out the apicids a set way. Modern summit HW (IBM x460) does not layout its bios in the manner for various reasons and is unable to boot i386 numa. The best way to get the correct apicid to node information is from the SRAT table during boot. It lays out what apicid belongs to what node. I use this information to create a table for use at run time. Signed-off-by: Keith Mannthey Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-i386/mach-summit/mach_apic.h | 2 +- include/asm-i386/smp.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/asm-i386/mach-summit/mach_apic.h b/include/asm-i386/mach-summit/mach_apic.h index a81b05961595..254a0fe01c6a 100644 --- a/include/asm-i386/mach-summit/mach_apic.h +++ b/include/asm-i386/mach-summit/mach_apic.h @@ -88,7 +88,7 @@ static inline void clustered_apic_check(void) static inline int apicid_to_node(int logical_apicid) { - return logical_apicid >> 5; /* 2 clusterids per CEC */ + return apicid_2_node[logical_apicid]; } /* Mapping from cpu number to logical apicid */ diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h index 32ac8c91d5c5..915c26a31b79 100644 --- a/include/asm-i386/smp.h +++ b/include/asm-i386/smp.h @@ -46,6 +46,8 @@ extern u8 x86_cpu_to_apicid[]; #define cpu_physical_id(cpu) x86_cpu_to_apicid[cpu] +extern u8 apicid_2_node[]; + #ifdef CONFIG_HOTPLUG_CPU extern void cpu_exit_clear(void); extern void cpu_uninit(void); -- cgit