Factoring out number of nodes calculation out of amd_get_topology()
and saving the value in a static variable.
A later patch will introduce a accessor for this value so we
can use the information elsewhere in EDAC. The usage will be
included in a future patch too.
While at it, remove X86_HT #ifdefs around the code block for
amd_get_topology() and it's caller amd_detect_cmp(). Since
CONFIG_X86_HT defaults to Y, this code is always built-in.
Besides, amd_get_topology() extracts necessary info from
cpuid_[eax|ebx](0x8000001e) for platforms that are not 'HT'
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Borislav Petkov <b...@suse.de>
Cc: Jacob Shin <jacob.w.s...@gmail.com>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrish...@amd.com>
---
arch/x86/kernel/cpu/amd.c | 36 +++++++++++++++++++++++++++---------
1 file changed, 27 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 94e7051..c595669 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -19,6 +19,13 @@
#include "cpu.h"
+/*
+ * nodes_per_processor: Specifies number of nodes per socket
+ * Refer Fam15h Models 00-0fh BKDG-
+ * CPUID Fn8000_001E_ECX Node Identifiers[10:8]
+ */
+static u32 nodes_per_processor = 1;
+
static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
{
u32 gprs[8] = { 0 };
@@ -282,25 +289,40 @@ static int nearby_node(int apicid)
}
#endif
+static void amd_set_num_nodes(void)
+{
+ if (cpu_has_topoext) {
+ u32 ecx;
+
+ ecx = cpuid_ecx(0x8000001e);
+ nodes_per_processor = ((ecx >> 8) & 7) + 1;
+ } else if (static_cpu_has(X86_FEATURE_NODEID_MSR)) {
+ u64 value;
+
+ rdmsrl(MSR_FAM10H_NODE_ID, value);
+ nodes_per_processor = ((value >> 3) & 7) + 1;
+ }
+}
+
/*
* Fixup core topology information for
* (1) AMD multi-node processors
* Assumption: Number of cores in each internal node is the same.
* (2) AMD processors supporting compute units
*/
-#ifdef CONFIG_X86_HT
static void amd_get_topology(struct cpuinfo_x86 *c)
{
- u32 nodes, cores_per_cu = 1;
+ u32 cores_per_cu = 1;
u8 node_id;
int cpu = smp_processor_id();
+ amd_set_num_nodes();
+
/* get information required for multi-node processors */
if (cpu_has_topoext) {
u32 eax, ebx, ecx, edx;
cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
- nodes = ((ecx >> 8) & 7) + 1;
node_id = ecx & 7;
/* get compute unit information */
@@ -311,18 +333,17 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
u64 value;
rdmsrl(MSR_FAM10H_NODE_ID, value);
- nodes = ((value >> 3) & 7) + 1;
node_id = value & 7;
} else
return;
/* fixup multi-node processor information */
- if (nodes > 1) {
+ if (nodes_per_processor > 1) {
u32 cores_per_node;
u32 cus_per_node;
set_cpu_cap(c, X86_FEATURE_AMD_DCM);
- cores_per_node = c->x86_max_cores / nodes;
+ cores_per_node = c->x86_max_cores / nodes_per_processor;
cus_per_node = cores_per_node / cores_per_cu;
/* store NodeID, use llc_shared_map to store sibling info */
@@ -333,7 +354,6 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
c->compute_unit_id %= cus_per_node;
}
}
-#endif
/*
* On a AMD dual core setup the lower bits of the APIC id distinguish the
cores.
@@ -341,7 +361,6 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
*/
static void amd_detect_cmp(struct cpuinfo_x86 *c)
{
-#ifdef CONFIG_X86_HT
unsigned bits;
int cpu = smp_processor_id();
@@ -353,7 +372,6 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c)
/* use socket ID also for last level cache */
per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
amd_get_topology(c);
-#endif
}
u16 amd_get_nb_id(int cpu)
--
2.4.0
--
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