From: Prarit Bhargava <prarit@redhat.com>
Date: Fri, 5 Mar 2010 19:41:20 -0500
Subject: [misc] add {thread,core}_siblings_list to /sys
Message-id: <20100305194120.30279.85323.sendpatchset@prarit.bos.redhat.com>
Patchwork-id: 23505
O-Subject: [RHEL5.6 PATCH]: add thread_siblings_list and core_siblings_list to
	/sys
Bugzilla: 570610
RH-Acked-by: Christopher Lalancette <clalance@redhat.com>
RH-Acked-by: Jarod Wilson <jarod@redhat.com>

>From clalance:

"libvirt depends on the kernel to get socket/core/thread topology information.
Currently this information is parsed out of /proc/cpuinfo, but I'm re-working
the code to use /sys/devices/system/cpu (see BZ 570527 for more details).  As
part of that, it would be easier to parse a formatted list of thread and core
siblings instead of the raw bitmask.  RHEL-5 currently provides the raw bitmask
in /sys/devices/system/cpu/cpu[0-9]*/topology/thread_sibilings, but it would be
easier to parse"

So I (Prarit) backported the upstream topology stuff to make clalance's
libvirt modification easier.

Brew built across all arches here:

http://brewweb.devel.redhat.com/brew/taskinfo?taskID=2303344

Successfully tested by me.

Resolves BZ 570610.

Signed-off-by: Jarod Wilson <jarod@redhat.com>

diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 3ef9d51..d1e9766 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -30,7 +30,10 @@
 #include <linux/module.h>
 #include <linux/topology.h>
 
-#define define_one_ro(_name) 		\
+#define define_one_ro_named(_name, _func)				\
+static SYSDEV_ATTR(_name, 0444, _func, NULL)
+
+#define define_one_ro(_name)				\
 static SYSDEV_ATTR(_name, 0444, show_##_name, NULL)
 
 #define define_id_show_func(name)				\
@@ -40,16 +43,54 @@ static ssize_t show_##name(struct sys_device *dev, char *buf)	\
 	return sprintf(buf, "%d\n", topology_##name(cpu));	\
 }
 
-#define define_siblings_show_func(name)					\
+static ssize_t show_cpumap(int type, const cpumask_t mask, char *buf)
+{
+	ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
+	int n = 0;
+
+	if (len > 1) {
+		n = type?
+			cpulist_scnprintf(buf, len-2, mask) :
+			cpumask_scnprintf(buf, len-2, mask);
+		buf[n++] = '\n';
+		buf[n] = '\0';
+	}
+	return n;
+}
+
+#ifdef arch_provides_topology_pointers
+#define define_siblings_show_map(name)					\
 static ssize_t show_##name(struct sys_device *dev, char *buf)		\
 {									\
-	ssize_t len = -1;						\
 	unsigned int cpu = dev->id;					\
-	len = cpumask_scnprintf(buf, NR_CPUS+1, topology_##name(cpu));	\
-	return (len + sprintf(buf + len, "\n"));			\
+	return show_cpumap(0, topology_##name(cpu), buf);		\
 }
 
-#ifdef	topology_physical_package_id
+#define define_siblings_show_list(name)					\
+static ssize_t show_##name##_list(struct sys_device *dev, char *buf)	\
+{									\
+	unsigned int cpu = dev->id;					\
+	return show_cpumap(1, topology_##name(cpu), buf);		\
+}
+
+#else
+#define define_siblings_show_map(name)					\
+static ssize_t show_##name(struct sys_device *dev, char *buf)		\
+{									\
+	return show_cpumap(0, topology_##name(dev->id), buf);		\
+}
+
+#define define_siblings_show_list(name)					\
+static ssize_t show_##name##_list(struct sys_device *dev, char *buf)	\
+{									\
+	return show_cpumap(1, topology_##name(dev->id), buf);		\
+}
+#endif
+
+#define define_siblings_show_func(name)		\
+	define_siblings_show_map(name); define_siblings_show_list(name)
+
+#ifdef topology_physical_package_id
 define_id_show_func(physical_package_id);
 define_one_ro(physical_package_id);
 #define ref_physical_package_id_attr	&attr_physical_package_id.attr,
@@ -65,27 +106,35 @@ define_one_ro(core_id);
 #define ref_core_id_attr
 #endif
 
-#ifdef topology_thread_siblings
-define_siblings_show_func(thread_siblings);
-define_one_ro(thread_siblings);
+#ifdef topology_thread_cpumask
+define_siblings_show_func(thread_cpumask);
+define_one_ro_named(thread_siblings, show_thread_cpumask);
+define_one_ro_named(thread_siblings_list, show_thread_cpumask_list);
 #define ref_thread_siblings_attr	&attr_thread_siblings.attr,
+#define ref_thread_siblings_list_attr	&attr_thread_siblings_list.attr,
 #else
 #define ref_thread_siblings_attr
+#define ref_thread_siblings_list_attr
 #endif
 
-#ifdef topology_core_siblings
-define_siblings_show_func(core_siblings);
-define_one_ro(core_siblings);
+#ifdef topology_core_cpumask
+define_siblings_show_func(core_cpumask);
+define_one_ro_named(core_siblings, show_core_cpumask);
+define_one_ro_named(core_siblings_list, show_core_cpumask_list);
 #define ref_core_siblings_attr		&attr_core_siblings.attr,
+#define ref_core_siblings_list_attr	&attr_core_siblings_list.attr,
 #else
 #define ref_core_siblings_attr
+#define ref_core_siblings_list_attr
 #endif
 
 static struct attribute *default_attrs[] = {
 	ref_physical_package_id_attr
 	ref_core_id_attr
 	ref_thread_siblings_attr
+	ref_thread_siblings_list_attr
 	ref_core_siblings_attr
+	ref_core_siblings_list_attr
 	NULL
 };
 
diff --git a/include/asm-i386/topology.h b/include/asm-i386/topology.h
index 9234497..0dbc5be 100644
--- a/include/asm-i386/topology.h
+++ b/include/asm-i386/topology.h
@@ -30,8 +30,8 @@
 #ifdef CONFIG_X86_HT
 #define topology_physical_package_id(cpu)	(cpu_data[cpu].phys_proc_id)
 #define topology_core_id(cpu)			(cpu_data[cpu].cpu_core_id)
-#define topology_core_siblings(cpu)		(cpu_core_map[cpu])
-#define topology_thread_siblings(cpu)		(cpu_sibling_map[cpu])
+#define topology_core_cpumask(cpu)		(cpu_core_map[cpu])
+#define topology_thread_cpumask(cpu)		(cpu_sibling_map[cpu])
 #endif
 
 #ifdef CONFIG_NUMA
diff --git a/include/asm-ia64/topology.h b/include/asm-ia64/topology.h
index 7d12dc6..2be14b2 100644
--- a/include/asm-ia64/topology.h
+++ b/include/asm-ia64/topology.h
@@ -110,8 +110,8 @@ void build_cpu_to_node_map(void);
 #ifdef CONFIG_SMP
 #define topology_physical_package_id(cpu)	(cpu_data(cpu)->socket_id)
 #define topology_core_id(cpu)			(cpu_data(cpu)->core_id)
-#define topology_core_siblings(cpu)		(cpu_core_map[cpu])
-#define topology_thread_siblings(cpu)		(cpu_sibling_map[cpu])
+#define topology_core_cpumask(cpu)		(cpu_core_map[cpu])
+#define topology_thread_cpumask(cpu)		(cpu_sibling_map[cpu])
 #define smt_capable() 				(smp_num_siblings > 1)
 #endif
 
diff --git a/include/asm-x86_64/topology.h b/include/asm-x86_64/topology.h
index c38717c..2d0def8 100644
--- a/include/asm-x86_64/topology.h
+++ b/include/asm-x86_64/topology.h
@@ -57,8 +57,8 @@ extern int __node_distance(int, int);
 #ifdef CONFIG_SMP
 #define topology_physical_package_id(cpu)	(cpu_data[cpu].phys_proc_id)
 #define topology_core_id(cpu)			(cpu_data[cpu].cpu_core_id)
-#define topology_core_siblings(cpu)		(cpu_core_map[cpu])
-#define topology_thread_siblings(cpu)		(cpu_sibling_map[cpu])
+#define topology_core_cpumask(cpu)		(cpu_core_map[cpu])
+#define topology_thread_cpumask(cpu)		(cpu_sibling_map[cpu])
 #define mc_capable()			(boot_cpu_data.x86_max_cores > 1)
 #define smt_capable() 			(smp_num_siblings > 1)
 #endif