[PATCH v2 0/2] x86/CPU/AMD: Add support for Extended Topology Enumeration

[PATCH v2 0/2] x86/CPU/AMD: Add support for Extended Topology Enumeration

[Suravee Suthikulpanit]

Linux currently provides function detect_extended_topology()
for parsing CPUID Fn0xB and derive CPU topology information.
Therefore, also call this function in AMD code path.

Please note that this series depend on the previously submitted
series:
  [PATCH 0/4] x86/CPU: Update AMD Last-Level-Cache Information 
  (https://lkml.org/lkml/2018/3/26/24)

Changes from v1 (https://lkml.org/lkml/2018/3/26/63)
  * 2/2 Fix and simplify the logic in amd_get_topology()

Thanks,
Suravee

Suravee Suthikulpanit (2):
  x86/CPU: Modify detect_extended_topology() to return result
  x86/CPU/AMD: Derive CPU topology from CPUID Fn0xB when available

 arch/x86/include/asm/processor.h |  2 +-
 arch/x86/kernel/cpu/amd.c        | 11 ++++++++++-
 arch/x86/kernel/cpu/topology.c   |  8 ++++----
 3 files changed, 15 insertions(+), 6 deletions(-)

-- 
2.7.4

[PATCH v2 1/2] x86/CPU: Modify detect_extended_topology() to return result

[Suravee Suthikulpanit]

Current implementation does not communicate whether it can successfully
detect CPUID Fn0x0000000B information. Therefore, modify the function
to return success or error codes. This will be used by subsequent patches.

Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 arch/x86/include/asm/processor.h | 2 +-
 arch/x86/kernel/cpu/topology.c   | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index b0ccd48..2a5d5ed 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -193,7 +193,7 @@ extern u32 get_scattered_cpuid_leaf(unsigned int level,
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
 
-extern void detect_extended_topology(struct cpuinfo_x86 *c);
+extern int detect_extended_topology(struct cpuinfo_x86 *c);
 extern void detect_ht(struct cpuinfo_x86 *c);
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
index b099024..81c0afb 100644
--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -27,7 +27,7 @@
  * exists, use it for populating initial_apicid and cpu topology
  * detection.
  */
-void detect_extended_topology(struct cpuinfo_x86 *c)
+int detect_extended_topology(struct cpuinfo_x86 *c)
 {
 #ifdef CONFIG_SMP
 	unsigned int eax, ebx, ecx, edx, sub_index;
@@ -36,7 +36,7 @@ void detect_extended_topology(struct cpuinfo_x86 *c)
 	static bool printed;
 
 	if (c->cpuid_level < 0xb)
-		return;
+		return -1;
 
 	cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
 
@@ -44,7 +44,7 @@ void detect_extended_topology(struct cpuinfo_x86 *c)
 	 * check if the cpuid leaf 0xb is actually implemented.
 	 */
 	if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
-		return;
+		return -1;
 
 	set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
 
@@ -95,6 +95,6 @@ void detect_extended_topology(struct cpuinfo_x86 *c)
 			       c->cpu_core_id);
 		printed = 1;
 	}
-	return;
 #endif
+	return 0;
 }
-- 
2.7.4

[PATCH v2 2/2] x86/CPU/AMD: Derive CPU topology from CPUID Fn0xB when available

[Suravee Suthikulpanit]

Derive topology information from Extended Topology Enumeration
(CPUID Fn0x0000000B) when the information is available.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 arch/x86/kernel/cpu/amd.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 2c1a9f2..cdd67d1 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -327,6 +327,7 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
 
 	/* get information required for multi-node processors */
 	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
+		int err;
 		u32 eax, ebx, ecx, edx;
 
 		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
@@ -344,6 +345,14 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
 				c->x86_max_cores /= smp_num_siblings;
 		}
 
+		/*
+		 * In case leaf B is avaialble, use leaf B to derive
+		 * topology information instead.
+		 */
+		err = detect_extended_topology(c);
+		if (!err)
+			c->x86_coreid_bits = get_count_order(c->x86_max_cores);
+
 		cacheinfo_amd_init_llc_id(c, cpu, node_id);
 
 	} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
@@ -378,7 +387,6 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c)
 	c->phys_proc_id = c->initial_apicid >> bits;
 	/* use socket ID also for last level cache */
 	per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
-	amd_get_topology(c);
 }
 
 u16 amd_get_nb_id(int cpu)
@@ -823,6 +831,7 @@ static void init_amd(struct cpuinfo_x86 *c)
 	/* Multi core CPU? */
 	if (c->extended_cpuid_level >= 0x80000008) {
 		amd_detect_cmp(c);
+		amd_get_topology(c);
 		srat_detect_node(c);
 	}
 
-- 
2.7.4

Re: [PATCH v2 2/2] x86/CPU/AMD: Derive CPU topology from CPUID Fn0xB when available

[Borislav Petkov]

On Wed, Apr 04, 2018 at 01:45:14AM -0500, Suravee Suthikulpanit wrote:
> Derive topology information from Extended Topology Enumeration
> (CPUID Fn0x0000000B) when the information is available.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> ---
>  arch/x86/kernel/cpu/amd.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index 2c1a9f2..cdd67d1 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -327,6 +327,7 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
>  
>  	/* get information required for multi-node processors */
>  	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
> +		int err;
>  		u32 eax, ebx, ecx, edx;
>  
>  		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
> @@ -344,6 +345,14 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
>  				c->x86_max_cores /= smp_num_siblings;
>  		}
>  
> +		/*
> +		 * In case leaf B is avaialble, use leaf B to derive

s/avaialble/available/

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--