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authorYazen Ghannam <yazen.ghannam@amd.com>2020-11-09 21:06:59 +0000
committerBorislav Petkov <bp@suse.de>2020-11-19 11:43:25 +0100
commitcb09a379724d299c603a7a79f444f52a9a75b8d2 (patch)
treed903f08aab4578393d19abcc8eb14b02e844f288 /arch/x86/kernel/cpu/topology.c
parent8de0c9917cc1297bc5543b61992d5bdee4ce621a (diff)
x86/topology: Set cpu_die_id only if DIE_TYPE found
CPUID Leaf 0x1F defines a DIE_TYPE level (nb: ECX[8:15] level type == 0x5), but CPUID Leaf 0xB does not. However, detect_extended_topology() will set struct cpuinfo_x86.cpu_die_id regardless of whether a valid Die ID was found. Only set cpu_die_id if a DIE_TYPE level is found. CPU topology code may use another value for cpu_die_id, e.g. the AMD NodeId on AMD-based systems. Code ordering should be maintained so that the CPUID Leaf 0x1F Die ID value will take precedence on systems that may use another value. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201109210659.754018-5-Yazen.Ghannam@amd.com
Diffstat (limited to 'arch/x86/kernel/cpu/topology.c')
-rw-r--r--arch/x86/kernel/cpu/topology.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
index d3a0791bc052..1068002c8532 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;
+ bool die_level_present = false;
int leaf;
leaf = detect_extended_topology_leaf(c);
@@ -126,6 +127,7 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
}
if (LEAFB_SUBTYPE(ecx) == DIE_TYPE) {
+ die_level_present = true;
die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
}
@@ -139,8 +141,12 @@ int detect_extended_topology(struct cpuinfo_x86 *c)
c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid,
ht_mask_width) & core_select_mask;
- c->cpu_die_id = apic->phys_pkg_id(c->initial_apicid,
- core_plus_mask_width) & die_select_mask;
+
+ if (die_level_present) {
+ c->cpu_die_id = apic->phys_pkg_id(c->initial_apicid,
+ core_plus_mask_width) & die_select_mask;
+ }
+
c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid,
die_plus_mask_width);
/*