[tip:x86/platform] x86: numachip: Fix 16-bit APIC ID truncation

From: tip-bot for Daniel J Blueman
Date: Tue Nov 04 2014 - 12:22:05 EST


Commit-ID: 00e7977dd1bbd46e336d7ef907d0fb6b6a4c294f
Gitweb: http://git.kernel.org/tip/00e7977dd1bbd46e336d7ef907d0fb6b6a4c294f
Author: Daniel J Blueman <daniel@xxxxxxxxxxxxx>
AuthorDate: Tue, 4 Nov 2014 16:29:41 +0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 4 Nov 2014 18:17:27 +0100

x86: numachip: Fix 16-bit APIC ID truncation

Prevent 16-bit APIC IDs being truncated by using correct mask. This fixes
booting large systems, where the wrong core would receive the startup and
init IPIs, causing hanging.

Signed-off-by: Daniel J Blueman <daniel@xxxxxxxxxxxxx>
Cc: Steffen Persvold <sp@xxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1415089784-28779-1-git-send-email-daniel@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/apic/apic_numachip.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index 4128b5f..2aaee79 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -40,7 +40,7 @@ static unsigned int get_apic_id(unsigned long x)
unsigned int id;

rdmsrl(MSR_FAM10H_NODE_ID, value);
- id = ((x >> 24) & 0xffU) | ((value << 2) & 0x3f00U);
+ id = ((x >> 24) & 0xffU) | ((value << 2) & 0xff00U);

return id;
}
--
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