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x86/cpu/amd: Derive L3 shared_cpu_map from cpu_llc_shared_mask

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For systems with X86_FEATURE_TOPOEXT, current logic uses the APIC ID
to calculate shared_cpu_map. However, APIC IDs are not guaranteed to
be contiguous for cores across different L3s (e.g. family17h system
w/ downcore configuration). This breaks the logic, and results in an
incorrect L3 shared_cpu_map.

Instead, always use the previously calculated cpu_llc_shared_mask of
each CPU to derive the L3 shared_cpu_map.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170731085159.9455-3-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Suravee Suthikulpanit 2017-07-31 10:51:59 +02:00 committed by Ingo Molnar
parent b89b41d0b8
commit 2b83809a5e
1 changed files with 18 additions and 14 deletions
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32
arch/x86/kernel/cpu/intel_cacheinfo.c
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@ -811,7 +811,24 @@ static int __cache_amd_cpumap_setup(unsigned int cpu, int index,
struct cacheinfo *this_leaf; struct cacheinfo *this_leaf;
int i, sibling; int i, sibling;
if (boot_cpu_has(X86_FEATURE_TOPOEXT)) { /*
* For L3, always use the pre-calculated cpu_llc_shared_mask
* to derive shared_cpu_map.
*/
if (index == 3) {
for_each_cpu(i, cpu_llc_shared_mask(cpu)) {
this_cpu_ci = get_cpu_cacheinfo(i);
if (!this_cpu_ci->info_list)
continue;
this_leaf = this_cpu_ci->info_list + index;
for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) {
if (!cpu_online(sibling))
continue;
cpumask_set_cpu(sibling,
&this_leaf->shared_cpu_map);
}
}
} else if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
unsigned int apicid, nshared, first, last; unsigned int apicid, nshared, first, last;
this_leaf = this_cpu_ci->info_list + index; this_leaf = this_cpu_ci->info_list + index;
@ -839,19 +856,6 @@ static int __cache_amd_cpumap_setup(unsigned int cpu, int index,
&this_leaf->shared_cpu_map); &this_leaf->shared_cpu_map);
} }
} }
} else if (index == 3) {
for_each_cpu(i, cpu_llc_shared_mask(cpu)) {
this_cpu_ci = get_cpu_cacheinfo(i);
if (!this_cpu_ci->info_list)
continue;
this_leaf = this_cpu_ci->info_list + index;
for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) {
if (!cpu_online(sibling))
continue;
cpumask_set_cpu(sibling,
&this_leaf->shared_cpu_map);
}
}
} else } else
return 0; return 0;