Commit e4b44434 authored by K Prateek Nayak's avatar K Prateek Nayak Committed by Peter Zijlstra
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x86/topology: Introduce topology_logical_core_id() 



On x86, topology_core_id() returns a unique core ID within the PKG
domain. Looking at match_smt() suggests that a core ID just needs to be
unique within a LLC domain. For use cases such as the core RAPL PMU,
there exists a need for a unique core ID across the entire system with
multiple PKG domains. Introduce topology_logical_core_id() to derive a
unique core ID across the system.

Signed-off-by: default avatarK Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: default avatarDhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarZhang Rui <rui.zhang@intel.com>
Reviewed-by: default avatar"Gautham R. Shenoy" <gautham.shenoy@amd.com>
Tested-by: default avatarK Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: default avatarOleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20241115060805.447565-3-Dhananjay.Ugwekar@amd.com
parent 2f2db347

Documentation/arch/x86/topology.rst

+4 −0
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@@ -135,6 +135,10 @@ Thread-related topology information in the kernel: 
    The ID of the core to which a thread belongs. It is also printed in /proc/cpuinfo

    "core_id."



  - topology_logical_core_id();



    The logical core ID to which a thread belongs.







System topology examples

arch/x86/include/asm/processor.h

+1 −0
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@@ -98,6 +98,7 @@ struct cpuinfo_topology { 
	// Logical ID mappings

	u32			logical_pkg_id;

	u32			logical_die_id;

	u32			logical_core_id;



	// AMD Node ID and Nodes per Package info

	u32			amd_node_id;

arch/x86/include/asm/topology.h

+1 −0
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@@ -143,6 +143,7 @@ extern const struct cpumask *cpu_clustergroup_mask(int cpu); 
#define topology_logical_package_id(cpu)	(cpu_data(cpu).topo.logical_pkg_id)

#define topology_physical_package_id(cpu)	(cpu_data(cpu).topo.pkg_id)

#define topology_logical_die_id(cpu)		(cpu_data(cpu).topo.logical_die_id)

#define topology_logical_core_id(cpu)		(cpu_data(cpu).topo.logical_core_id)

#define topology_die_id(cpu)			(cpu_data(cpu).topo.die_id)

#define topology_core_id(cpu)			(cpu_data(cpu).topo.core_id)

#define topology_ppin(cpu)			(cpu_data(cpu).ppin)

arch/x86/kernel/cpu/debugfs.c

+1 −0
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@@ -25,6 +25,7 @@ static int cpu_debug_show(struct seq_file *m, void *p) 
	seq_printf(m, "cpu_type:            %s\n", get_topology_cpu_type_name(c));

	seq_printf(m, "logical_pkg_id:      %u\n", c->topo.logical_pkg_id);

	seq_printf(m, "logical_die_id:      %u\n", c->topo.logical_die_id);

	seq_printf(m, "logical_core_id:     %u\n", c->topo.logical_core_id);

	seq_printf(m, "llc_id:              %u\n", c->topo.llc_id);

	seq_printf(m, "l2c_id:              %u\n", c->topo.l2c_id);

	seq_printf(m, "amd_node_id:         %u\n", c->topo.amd_node_id);

arch/x86/kernel/cpu/topology_common.c

+1 −0
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@@ -185,6 +185,7 @@ static void topo_set_ids(struct topo_scan *tscan, bool early) 
	if (!early) {

		c->topo.logical_pkg_id = topology_get_logical_id(apicid, TOPO_PKG_DOMAIN);

		c->topo.logical_die_id = topology_get_logical_id(apicid, TOPO_DIE_DOMAIN);

		c->topo.logical_core_id = topology_get_logical_id(apicid, TOPO_CORE_DOMAIN);

	}



	/* Package relative core ID */