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Commit 345077cd authored by Suresh Siddha's avatar Suresh Siddha Committed by Ingo Molnar
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x86: fix intel x86_64 llc_shared_map/cpu_llc_id anomolies 



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: default avatarDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: default avatarDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
parent 40fb1715

arch/x86/kernel/cpu/addon_cpuid_features.c

+8 −0
Original line number Diff line number Diff line
@@ -120,9 +120,17 @@ void __cpuinit detect_extended_topology(struct cpuinfo_x86 *c) 
	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);

arch/x86/kernel/cpu/intel.c

+7 −1
Original line number Diff line number Diff line
@@ -252,6 +252,13 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) 


	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);
@@ -323,7 +330,6 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) 


#endif



	detect_extended_topology(c);

	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {

		/*

		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology