[tip:x86/amd-nb] x86, amd: Initialize variable properly

From: tip-bot for Borislav Petkov
Date: Mon Feb 14 2011 - 22:10:59 EST


Commit-ID: 9e81509efc4fefcdd75cc6a4121672fa71ae8745
Gitweb: http://git.kernel.org/tip/9e81509efc4fefcdd75cc6a4121672fa71ae8745
Author: Borislav Petkov <bp@xxxxxxxxx>
AuthorDate: Mon, 14 Feb 2011 18:14:51 +0100
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 15 Feb 2011 03:03:19 +0100

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@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx>
Cc: Andreas Herrmann <andreas.herrmann3@xxxxxxx>
LKML-Reference: <20110214171451.GB10076@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/cpu/amd.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 990cc48..589bdd7 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;
}
--
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