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x86/topology: Fix multiple packages shown on a single-package system

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[ Upstream commit 2b12a7a126d62bdbd81f4923c21bf6e9a7fbd069 ]

CPUID.1F/B does not enumerate Package level explicitly, instead, all the
APIC-ID bits above the enumerated levels are assumed to be package ID
bits.

Current code gets package ID by shifting out all the APIC-ID bits that
Linux supports, rather than shifting out all the APIC-ID bits that
CPUID.1F enumerates. This introduces problems when CPUID.1F enumerates a
level that Linux does not support.

For example, on a single package AlderLake-N, there are 2 Ecore Modules
with 4 atom cores in each module.  Linux does not support the Module
level and interprets the Module ID bits as package ID and erroneously
reports a multi module system as a multi-package system.

Fix this by using APIC-ID bits above all the CPUID.1F enumerated levels
as package ID.

[ dhansen: spelling fix ]

Fixes: 7745f03eb3 ("x86/topology: Add CPUID.1F multi-die/package support")
Suggested-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20221014090147.1836-4-rui.zhang@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Zhang Rui
2022-10-14 17:01:46 +08:00
committed by Greg Kroah-Hartman
parent f5ad52da14
commit 6c31fc028a
1 changed files with 10 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
arch/x86/kernel/cpu/topology.c
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@@ -96,6 +96,7 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
unsigned int ht_mask_width, core_plus_mask_width, die_plus_mask_width;
unsigned int core_select_mask, core_level_siblings;
unsigned int die_select_mask, die_level_siblings;
unsigned int pkg_mask_width;
bool die_level_present = false;
int leaf;
@@ -111,10 +112,10 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
sub_index = 1;
do {
while (true) {
cpuid_count(leaf, sub_index, &eax, &ebx, &ecx, &edx);
/*
@@ -132,8 +133,13 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
}
if (LEAFB_SUBTYPE(ecx) != INVALID_TYPE)
pkg_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
else
break;
sub_index++;
} while (LEAFB_SUBTYPE(ecx) != INVALID_TYPE);
}
core_select_mask = (~(-1 << core_plus_mask_width)) >> ht_mask_width;
die_select_mask = (~(-1 << die_plus_mask_width)) >>
@@ -148,7 +154,7 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
}
c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid,
die_plus_mask_width);
pkg_mask_width);
/*
* Reinit the apicid, now that we have extended initial_apicid.
*/