[PATCH 03/19] cpu topology: Export die_id

From: Len Brown
Date: Mon May 13 2019 - 14:00:56 EST


From: Len Brown <len.brown@xxxxxxxxx>

Export die_id in cpu topology, for the benefit of hardware that
has multiple-die/package.

Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
---
Documentation/cputopology.txt | 15 ++++++++++++---
drivers/base/topology.c | 4 ++++
include/linux/topology.h | 3 +++
3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt
index cb61277e2308..2ff8a1e9a2db 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
@@ -81,6 +87,7 @@ For an architecture to support this feature, it must define some of
these macros in include/asm-XXX/topology.h::

#define topology_physical_package_id(cpu)
+ #define topology_die_id(cpu)
#define topology_core_id(cpu)
#define topology_book_id(cpu)
#define topology_drawer_id(cpu)
@@ -99,9 +106,11 @@ provides default definitions for any of the above macros that are
not defined by include/asm-XXX/topology.h:

1) topology_physical_package_id: -1
-2) topology_core_id: 0
-3) topology_sibling_cpumask: just the given CPU
-4) topology_core_cpumask: just the given CPU
+2) topology_die_id: -1
+3) topology_core_id: 0
+4) topology_sibling_cpumask: just the given CPU
+5) topology_core_cpumask: just the given CPU
+6) topology_die_cpumask: just the given CPU

For architectures that don't support books (CONFIG_SCHED_BOOK) there are no
default definitions for topology_book_id() and topology_book_cpumask().
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