From: Borislav Petkov <bp@amd64.org>
Date: Mon, 14 Feb 2011 17:14:51 +0000 (+0100)
Subject: x86, amd: Initialize variable properly
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9e81509efc4fefcdd75cc6a4121672fa71ae8745;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

x86, amd: Initialize variable properly

Commit d518573de63f ("x86, amd: Normalize compute unit IDs on
multi-node processors") introduced compute unit normalization
but causes a compiler warning:

 arch/x86/kernel/cpu/amd.c: In function 'amd_detect_cmp':
 arch/x86/kernel/cpu/amd.c:268: warning: 'cores_per_cu' may be used uninitialized in this function
 arch/x86/kernel/cpu/amd.c:268: note: 'cores_per_cu' was declared here

The compiler is right - initialize it with a proper value.

Also, fix up a comment while at it.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20110214171451.GB10076@kryptos.osrc.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 990cc486158..589bdd7a4cf 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -261,7 +261,7 @@ static int __cpuinit nearby_node(int apicid)
 #ifdef CONFIG_X86_HT
 static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c)
 {
-	u32 nodes, cores_per_cu;
+	u32 nodes, cores_per_cu = 1;
 	u8 node_id;
 	int cpu = smp_processor_id();
 
@@ -276,7 +276,7 @@ static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c)
 		/* get compute unit information */
 		smp_num_siblings = ((ebx >> 8) & 3) + 1;
 		c->compute_unit_id = ebx & 0xff;
-		cores_per_cu = ((ebx >> 8) & 3) + 1;
+		cores_per_cu += ((ebx >> 8) & 3);
 	} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
 		u64 value;
 
@@ -298,7 +298,7 @@ static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c)
 		/* store NodeID, use llc_shared_map to store sibling info */
 		per_cpu(cpu_llc_id, cpu) = node_id;
 
-		/* core id to be in range from 0 to (cores_per_node - 1) */
+		/* core id has to be in the [0 .. cores_per_node - 1] range */
 		c->cpu_core_id %= cores_per_node;
 		c->compute_unit_id %= cus_per_node;
 	}