[PATCH v4 1/4] Numachip: Fix 16-bit APIC ID truncation

From: Daniel J Blueman
Date: Tue Nov 04 2014 - 03:31:18 EST


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>
---
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 81d70ba..bd083c0 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;
}
--
1.9.1

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