From: Zhang Rui <rui.zhang@intel.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org,
linux-hwmon@vger.kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, hpa@zytor.com, corbet@lwn.net,
fenghua.yu@intel.com, jdelvare@suse.com, linux@roeck-us.net,
len.brown@intel.com, rui.zhang@intel.com
Subject: [PATCH V2 4/8] x86/topology: Fix multiple packages shown on a single-package system
Date: Tue, 16 Aug 2022 13:16:29 +0800 [thread overview]
Message-ID: <20220816051633.17775-5-rui.zhang@intel.com> (raw)
In-Reply-To: <20220816051633.17775-1-rui.zhang@intel.com>
CPUID.1F/B does not emumerate 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 an AlderLake-N platform, there are 2 Ecore Modules, which
has 4 atom cores in each module, in a single package.
Linux does not support 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.
Suggested-and-reviewed-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
arch/x86/kernel/cpu/topology.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
index 132a2de44d2f..f7592814e5d5 100644
--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -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.
*/
--
2.25.1
next prev parent reply other threads:[~2022-08-16 7:57 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-16 5:16 [PATCH V2 0/8] x86/topology: Improve CPUID.1F handling Zhang Rui
2022-08-16 5:16 ` [PATCH V2 1/8] perf/x86/intel/P4: Fix smp_num_siblings usage Zhang Rui
2022-08-16 8:27 ` Peter Zijlstra
2022-08-16 9:47 ` Zhang Rui
2022-08-16 10:08 ` Peter Zijlstra
2022-08-16 5:16 ` [PATCH V2 2/8] hwmon/coretemp: Rename indx to index Zhang Rui
2022-08-16 5:16 ` [PATCH V2 3/8] hwmon/coretemp: Handle large core ID value Zhang Rui
2022-08-16 11:16 ` Guenter Roeck
2022-08-16 5:16 ` Zhang Rui [this message]
2022-09-21 16:26 ` [PATCH V2 4/8] x86/topology: Fix multiple packages shown on a single-package system Dave Hansen
2022-09-22 13:38 ` Zhang Rui
2022-08-16 5:16 ` [PATCH V2 5/8] x86/topology: Fix duplicated core ID within a package Zhang Rui
2022-08-16 5:16 ` [PATCH V2 6/8] x86/topology: Fix max_siblings calculation Zhang Rui
2022-08-16 5:16 ` [PATCH V2 7/8] Documentation: x86: Update smp_num_siblings/x86_max_cores description Zhang Rui
2022-08-16 5:16 ` [PATCH V2 8/8] Documentation: x86: Remove obsolete x86_max_dies description Zhang Rui
2022-09-20 1:57 ` [PATCH V2 0/8] x86/topology: Improve CPUID.1F handling Zhang Rui
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