[patch 05/94] x86: fix intel x86_64 llc_shared_map/cpu_llc_idanomolies

[Greg KH]

2.6.28-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>

commit 345077cd98ff5532b2d1158013c3fec7b1ae85ec upstream.

Impact: fix wrong cache sharing detection on platforms supporting > 8 bit apicid's

In the presence of extended topology eumeration leaf 0xb provided
by cpuid, 32bit extended initial_apicid in cpuinfo_x86 struct will be
updated by detect_extended_topology(). At this instance, we should also
reinit the apicid (which could also potentially be extended to 32bit).

With out this there will potentially be duplicate apicid's populated in the
per cpu's cpuinfo_x86 struct, resulting in wrong cache sharing topology etc
detected by init_intel_cacheinfo().

Reported-by: Dimitri Sivanich <sivanich@xxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Acked-by: Dimitri Sivanich <sivanich@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/x86/kernel/cpu/addon_cpuid_features.c |    8 ++++++++
 arch/x86/kernel/cpu/intel.c                |    8 +++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/addon_cpuid_features.c
+++ b/arch/x86/kernel/cpu/addon_cpuid_features.c
@@ -120,9 +120,17 @@ void __cpuinit detect_extended_topology(
 	c->cpu_core_id = phys_pkg_id(c->initial_apicid, ht_mask_width)
 						 & core_select_mask;
 	c->phys_proc_id = phys_pkg_id(c->initial_apicid, core_plus_mask_width);
+	/*
+	 * Reinit the apicid, now that we have extended initial_apicid.
+	 */
+	c->apicid = phys_pkg_id(c->initial_apicid, 0);
 #else
 	c->cpu_core_id = phys_pkg_id(ht_mask_width) & core_select_mask;
 	c->phys_proc_id = phys_pkg_id(core_plus_mask_width);
+	/*
+	 * Reinit the apicid, now that we have extended initial_apicid.
+	 */
+	c->apicid = phys_pkg_id(0);
 #endif
 	c->x86_max_cores = (core_level_siblings / smp_num_siblings);
 
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -242,6 +242,13 @@ static void __cpuinit init_intel(struct 
 
 	intel_workarounds(c);
 
+	/*
+	 * Detect the extended topology information if available. This
+	 * will reinitialise the initial_apicid which will be used
+	 * in init_intel_cacheinfo()
+	 */
+	detect_extended_topology(c);
+
 	l2 = init_intel_cacheinfo(c);
 	if (c->cpuid_level > 9) {
 		unsigned eax = cpuid_eax(10);
@@ -313,7 +320,6 @@ static void __cpuinit init_intel(struct 
 
 #endif
 
-	detect_extended_topology(c);
 	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
 		/*
 		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology

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