Export die_id in cpu topology, for the benefit of hardware that
has multiple die per package. die_id is quite similar to core_id,
in that it holds multiple CPUs, but is inside a package.
This needed by topology-aware user-space. In particular,
an application, such as turbostat(8), which needs to know
the actual scope of "package-scope" MSRs.
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
Documentation/cputopology.txt | 10 ++++++++--
arch/x86/include/asm/topology.h | 1 +
drivers/base/topology.c | 4 ++++
include/linux/topology.h | 3 +++
4 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt
index 2698da7e4f49..287213b4517b 100644
--- a/Documentation/cputopology.txt
+++ b/Documentation/cputopology.txt
@@ -12,6 +12,12 @@ physical_package_id:
socket number, but the actual value is architecture and platform
dependent.
+die_id:
+
+ the CPU die ID of cpuX. Typically it is the hardware platform's
+ identifier (rather than the kernel's). The actual value is
+ architecture and platform dependent.
+
core_id:
the CPU core ID of cpuX. Typically it is the hardware platform's
@@ -43,12 +49,12 @@ thread_siblings_list:
core_siblings:
internal kernel map of cpuX's hardware threads within the same
- physical_package_id.
+ die_id.
core_siblings_list:
human-readable list of cpuX's hardware threads within the same
- physical_package_id.
+ die_id.
book_siblings:
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 453cf38a1c33..281be6bbc80d 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -106,6 +106,7 @@ extern const struct cpumask *cpu_coregroup_mask(int cpu);
#define topology_logical_package_id(cpu) (cpu_data(cpu).logical_proc_id)
#define topology_physical_package_id(cpu) (cpu_data(cpu).phys_proc_id)
+#define topology_die_id(cpu) (cpu_data(cpu).cpu_die_id)
#define topology_core_id(cpu) (cpu_data(cpu).cpu_core_id)
#ifdef CONFIG_SMP
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 5fd9f167ecc1..50352cf96f85 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -43,6 +43,9 @@ static ssize_t name##_list_show(struct device *dev, \
define_id_show_func(physical_package_id);
static DEVICE_ATTR_RO(physical_package_id);
+define_id_show_func(die_id);
+static DEVICE_ATTR_RO(die_id);
+
define_id_show_func(core_id);
static DEVICE_ATTR_RO(core_id);
@@ -72,6 +75,7 @@ static DEVICE_ATTR_RO(drawer_siblings_list);
static struct attribute *default_attrs[] = {
&dev_attr_physical_package_id.attr,
+ &dev_attr_die_id.attr,
&dev_attr_core_id.attr,
&dev_attr_thread_siblings.attr,
&dev_attr_thread_siblings_list.attr,
diff --git a/include/linux/topology.h b/include/linux/topology.h
index cb0775e1ee4b..5cc8595dd0e4 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -184,6 +184,9 @@ static inline int cpu_to_mem(int cpu)
#ifndef topology_physical_package_id
#define topology_physical_package_id(cpu) ((void)(cpu), -1)
#endif
+#ifndef topology_die_id
+#define topology_die_id(cpu) ((void)(cpu), -1)
+#endif
#ifndef topology_core_id
#define topology_core_id(cpu) ((void)(cpu), 0)
#endif
--
2.18.0-rc0
