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authorDavid S. Miller <davem@sunset.davemloft.net>2007-08-15 21:02:23 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-08-15 21:02:23 -0700
commit0fdb7f96d8c27e37ed2ca1ae5a763baf14b8fe0c (patch)
treee6ad3272da135d92929a8ea7f920baa63c973d4a /arch/sparc64/kernel/mdesc.c
parent70b0e7a919b7961285c685a87928ed78c9fb07f0 (diff)
downloadlinux-linaro-0fdb7f96d8c27e37ed2ca1ae5a763baf14b8fe0c.tar.gz
[SPARC64]: Allow userspace to get at the machine description.
Like the OF device tree, it's useful to let userland get at the machine description so it can pretty print the graph etc. The implementation is a simple MISC device with a read method. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64/kernel/mdesc.c')
-rw-r--r--arch/sparc64/kernel/mdesc.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/mdesc.c b/arch/sparc64/kernel/mdesc.c
index 95059c2ec41..9f22e4ff601 100644
--- a/arch/sparc64/kernel/mdesc.c
+++ b/arch/sparc64/kernel/mdesc.c
@@ -9,6 +9,7 @@
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/mm.h>
+#include <linux/miscdevice.h>
#include <asm/hypervisor.h>
#include <asm/mdesc.h>
@@ -836,6 +837,43 @@ void __devinit mdesc_fill_in_cpu_data(cpumask_t mask)
mdesc_release(hp);
}
+static ssize_t mdesc_read(struct file *file, char __user *buf,
+ size_t len, loff_t *offp)
+{
+ struct mdesc_handle *hp = mdesc_grab();
+ int err;
+
+ if (!hp)
+ return -ENODEV;
+
+ err = hp->handle_size;
+ if (len < hp->handle_size)
+ err = -EMSGSIZE;
+ else if (copy_to_user(buf, &hp->mdesc, hp->handle_size))
+ err = -EFAULT;
+ mdesc_release(hp);
+
+ return err;
+}
+
+static const struct file_operations mdesc_fops = {
+ .read = mdesc_read,
+ .owner = THIS_MODULE,
+};
+
+static struct miscdevice mdesc_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "mdesc",
+ .fops = &mdesc_fops,
+};
+
+static int __init mdesc_misc_init(void)
+{
+ return misc_register(&mdesc_misc);
+}
+
+__initcall(mdesc_misc_init);
+
void __init sun4v_mdesc_init(void)
{
struct mdesc_handle *hp;