[PATCH] powerpc: Add support for changing properties from userspace

Add support to reconfigure the device tree through the existing
proc filesystem interface.  Add "add_property", "remove_property",
and "update_property" commands to the existing interface.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index d8864164dbe809c85c012fe03957e96d4b398ff4..86cfa6ecdcf3b55ae6e2468400650258d48e4231 100644 (file)
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -350,6 +350,100 @@ static int do_remove_node(char *buf)
        return rv;
 }
 
+static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
+{
+       char *handle_str;
+       phandle handle;
+       *npp = NULL;
+
+       handle_str = buf;
+
+       buf = strchr(buf, ' ');
+       if (!buf)
+               return NULL;
+       *buf = '\0';
+       buf++;
+
+       handle = simple_strtoul(handle_str, NULL, 10);
+
+       *npp = of_find_node_by_phandle(handle);
+       return buf;
+}
+
+static int do_add_property(char *buf, size_t bufsize)
+{
+       struct property *prop = NULL;
+       struct device_node *np;
+       unsigned char *value;
+       char *name, *end;
+       int length;
+       end = buf + bufsize;
+       buf = parse_node(buf, bufsize, &np);
+
+       if (!np)
+               return -ENODEV;
+
+       if (parse_next_property(buf, end, &name, &length, &value) == NULL)
+               return -EINVAL;
+
+       prop = new_property(name, length, value, NULL);
+       if (!prop)
+               return -ENOMEM;
+
+       prom_add_property(np, prop);
+
+       return 0;
+}
+
+static int do_remove_property(char *buf, size_t bufsize)
+{
+       struct device_node *np;
+       char *tmp;
+       struct property *prop;
+       buf = parse_node(buf, bufsize, &np);
+
+       if (!np)
+               return -ENODEV;
+
+       tmp = strchr(buf,' ');
+       if (tmp)
+               *tmp = '\0';
+
+       if (strlen(buf) == 0)
+               return -EINVAL;
+
+       prop = of_find_property(np, buf, NULL);
+
+       return prom_remove_property(np, prop);
+}
+
+static int do_update_property(char *buf, size_t bufsize)
+{
+       struct device_node *np;
+       unsigned char *value;
+       char *name, *end;
+       int length;
+       struct property *newprop, *oldprop;
+       buf = parse_node(buf, bufsize, &np);
+       end = buf + bufsize;
+
+       if (!np)
+               return -ENODEV;
+
+       if (parse_next_property(buf, end, &name, &length, &value) == NULL)
+               return -EINVAL;
+
+       newprop = new_property(name, length, value, NULL);
+       if (!newprop)
+               return -ENOMEM;
+
+       oldprop = of_find_property(np, name,NULL);
+       if (!oldprop)
+               return -ENODEV;
+
+       return prom_update_property(np, newprop, oldprop);
+}
+
 /**
  * ofdt_write - perform operations on the Open Firmware device tree
  *
@@ -392,6 +486,12 @@ static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t coun
                rv = do_add_node(tmp, count - (tmp - kbuf));
        else if (!strcmp(kbuf, "remove_node"))
                rv = do_remove_node(tmp);
+       else if (!strcmp(kbuf, "add_property"))
+               rv = do_add_property(tmp, count - (tmp - kbuf));
+       else if (!strcmp(kbuf, "remove_property"))
+               rv = do_remove_property(tmp, count - (tmp - kbuf));
+       else if (!strcmp(kbuf, "update_property"))
+               rv = do_update_property(tmp, count - (tmp - kbuf));
        else
                rv = -EINVAL;
 out: