There are instances in which we do not want topology updates to occur.
In order to allow this a /proc interface (/proc/powerpc/topology_updates)
is introduced so that topology updates can be enabled and disabled.
This patch also adds a prrn_is_enabled() call so that PRRN events are
handled in the kernel only if topology updating is enabled.
Signed-off-by: Nathan Fontenot <nf...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/topology.h | 5 ++
arch/powerpc/kernel/rtasd.c | 7 ++--
arch/powerpc/mm/numa.c | 62 +++++++++++++++++++++++++++++++++++-
3 files changed, 71 insertions(+), 3 deletions(-)
Index: powerpc/arch/powerpc/mm/numa.c
===================================================================
--- powerpc.orig/arch/powerpc/mm/numa.c 2013-04-22 09:46:13.000000000 -0500
+++ powerpc/arch/powerpc/mm/numa.c 2013-04-22 09:51:10.000000000 -0500
@@ -23,6 +23,9 @@
#include <linux/cpuset.h>
#include <linux/node.h>
#include <linux/stop_machine.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
#include <asm/sparsemem.h>
#include <asm/prom.h>
#include <asm/smp.h>
@@ -1585,7 +1588,6 @@
return rc;
}
-__initcall(start_topology_update);
/*
* Disable polling for VPHN associativity changes.
@@ -1604,4 +1606,62 @@
return rc;
}
+
+inline int prrn_is_enabled(void)
+{
+ return prrn_enabled;
+}
+
+static int topology_read(struct seq_file *file, void *v)
+{
+ if (vphn_enabled || prrn_enabled)
+ seq_puts(file, "on\n");
+ else
+ seq_puts(file, "off\n");
+
+ return 0;
+}
+
+static int topology_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, topology_read, NULL);
+}
+
+static ssize_t topology_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *off)
+{
+ char kbuf[4]; /* "on" or "off" plus null. */
+ int read_len;
+
+ read_len = count < 3 ? count : 3;
+ if (copy_from_user(kbuf, buf, read_len))
+ return -EINVAL;
+
+ kbuf[read_len] = '\0';
+
+ if (!strncmp(kbuf, "on", 2))
+ start_topology_update();
+ else if (!strncmp(kbuf, "off", 3))
+ stop_topology_update();
+ else
+ return -EINVAL;
+
+ return count;
+}
+
+static const struct file_operations topology_ops = {
+ .read = seq_read,
+ .write = topology_write,
+ .open = topology_open,
+ .release = single_release
+};
+
+static int topology_update_init(void)
+{
+ start_topology_update();
+ proc_create("powerpc/topology_updates", 644, NULL, &topology_ops);
+
+ return 0;
+}
+device_initcall(topology_update_init);
#endif /* CONFIG_PPC_SPLPAR */
Index: powerpc/arch/powerpc/include/asm/topology.h
===================================================================
--- powerpc.orig/arch/powerpc/include/asm/topology.h 2013-04-18
09:09:21.000000000 -0500
+++ powerpc/arch/powerpc/include/asm/topology.h 2013-04-22 09:51:10.000000000
-0500
@@ -71,6 +71,7 @@
#if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR)
extern int start_topology_update(void);
extern int stop_topology_update(void);
+extern inline int prrn_is_enabled(void);
#else
static inline int start_topology_update(void)
{
@@ -80,6 +81,10 @@
{
return 0;
}
+static inline int prrn_is_enabled(void)
+{
+ return 0;
+}
#endif /* CONFIG_NUMA && CONFIG_PPC_SPLPAR */
#include <asm-generic/topology.h>
Index: powerpc/arch/powerpc/kernel/rtasd.c
===================================================================
--- powerpc.orig/arch/powerpc/kernel/rtasd.c 2013-04-18 09:09:21.000000000
-0500
+++ powerpc/arch/powerpc/kernel/rtasd.c 2013-04-22 09:51:10.000000000 -0500
@@ -29,6 +29,7 @@
#include <asm/nvram.h>
#include <linux/atomic.h>
#include <asm/machdep.h>
+#include <asm/topology.h>
static DEFINE_SPINLOCK(rtasd_log_lock);
@@ -294,11 +295,13 @@
{
pSeries_log_error((char *)log, ERR_TYPE_RTAS_LOG, 0);
- if (log->type == RTAS_TYPE_PRRN)
+ if (log->type == RTAS_TYPE_PRRN) {
/* For PRRN Events the extended log length is used to denote
* the scope for calling rtas update-nodes.
*/
- prrn_schedule_update(log->extended_log_length);
+ if (prrn_is_enabled())
+ prrn_schedule_update(log->extended_log_length);
+ }
return;
}
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