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author | Nathan Fontenot <nfont@linux.vnet.ibm.com> | 2013-04-24 06:07:39 +0000 |
---|---|---|
committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-04-26 16:08:26 +1000 |
commit | e04fa61214a3e586282490af7e1b023522c1472a (patch) | |
tree | 44efd1187b1b9d77341cec4b80c4355a36a73afb /arch/powerpc/mm/numa.c | |
parent | 1b1218d32efdc81134eeb908935a18659cb3d9d7 (diff) | |
download | op-kernel-dev-e04fa61214a3e586282490af7e1b023522c1472a.zip op-kernel-dev-e04fa61214a3e586282490af7e1b023522c1472a.tar.gz |
powerpc/pseries: Add /proc interface to control topology updates
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 <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/mm/numa.c')
-rw-r--r-- | arch/powerpc/mm/numa.c | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 908699f..2d13f90 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -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 @@ int start_topology_update(void) return rc; } -__initcall(start_topology_update); /* * Disable polling for VPHN associativity changes. @@ -1604,4 +1606,62 @@ int stop_topology_update(void) return rc; } + +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 */ |