[PATCH] ibmebus: change probe/remove interface from using loc-code to DT path

From: Joachim Fenkes
Date: Thu Mar 22 2007 - 12:04:20 EST


In some cases, multiple OFDT nodes might share the same location code, so
the location code is not a unique identifier for an OFDT node. Changed the
ibmebus probe/remove interface to use the DT path of the device node instead
of the location code.

The DT path must be written into probe/remove right as it would appear in
the "devspec" attribute of the ebus device: relative to the DT root, with a
leading slash and without a trailing slash. One trailing newline will not
hurt; multiple newlines will (like perl's chomp()).

Example:

Add a device "/proc/device-tree/foo@12345678" to ibmebus like this:
echo /foo@12345678 > /sys/bus/ibmebus/probe

Remove the device like this:
echo /foo@12345678 > /sys/bus/ibmebus/remove


Signed-off-by: Joachim Fenkes <fenkes@xxxxxxxxxx>
---


This patch applies on top of part 2/3 or 3/3 of my previous ibmebus patches,
which are already in Paul's git. Part 3/3 of that patchset will still apply
cleanly (with a little offset) after this patch.


ibmebus.c | 118 ++++++++++++++++++++++++++++++++------------------------------
1 file changed, 61 insertions(+), 57 deletions(-)


diff -Nurp 03.almost-all/arch/powerpc/kernel/ibmebus.c 03b.path/arch/powerpc/kernel/ibmebus.c
--- 03.almost-all/arch/powerpc/kernel/ibmebus.c 2007-03-09 17:37:08.000000000 +0100
+++ 03b.path/arch/powerpc/kernel/ibmebus.c 2007-03-21 15:23:23.358121376 +0100
@@ -44,8 +44,6 @@
#include <asm/ibmebus.h>
#include <asm/abs_addr.h>

-#define MAX_LOC_CODE_LENGTH 80
-
static struct device ibmebus_bus_device = { /* fake "parent" device */
.bus_id = "ibmebus",
};
@@ -253,7 +251,7 @@ static void ibmebus_add_devices_by_id(st
return;
}

-static int ibmebus_match_helper_name(struct device *dev, void *data)
+static int ibmebus_match_name(struct device *dev, void *data)
{
const struct ibmebus_dev *ebus_dev = to_ibmebus_dev(dev);
char *name;
@@ -281,7 +279,7 @@ static void ibmebus_remove_devices_by_id
while (strlen(idt->name) > 0) {
while ((dev = bus_find_device(&ibmebus_bus_type, NULL,
(void*)idt->name,
- ibmebus_match_helper_name))) {
+ ibmebus_match_name))) {
ibmebus_unregister_device(dev);
}
idt++;
@@ -372,18 +370,30 @@ static struct device_attribute ibmebus_d
__ATTR_NULL
};

-static int ibmebus_match_helper_loc_code(struct device *dev, void *data)
+static int ibmebus_match_path(struct device *dev, void *data)
{
- const struct ibmebus_dev *ebus_dev = to_ibmebus_dev(dev);
- char *loc_code;
+ int rc;
+ struct device_node *dn =
+ of_node_get(to_ibmebus_dev(dev)->ofdev.node);

- loc_code = (char*)get_property(
- ebus_dev->ofdev.node, "ibm,loc-code", NULL);
+ rc = (dn->full_name && (strcasecmp((char*)data, dn->full_name) == 0));

- if (loc_code && (strcmp((char*)data, loc_code) == 0))
- return 1;
+ of_node_put(dn);
+ return rc;
+}

- return 0;
+static char *ibmebus_chomp(const char *in, size_t count)
+{
+ char *out = (char*)kmalloc(count + 1, GFP_KERNEL);
+ if (!out)
+ return NULL;
+
+ memcpy(out, in, count);
+ out[count] = '\0';
+ if (out[count - 1] == '\n')
+ out[count - 1] = '\0';
+
+ return out;
}

static ssize_t ibmebus_store_probe(struct bus_type *bus,
@@ -391,65 +401,59 @@ static ssize_t ibmebus_store_probe(struc
{
struct device_node *dn = NULL;
struct ibmebus_dev *dev;
- char *loc_code;
- char parm[MAX_LOC_CODE_LENGTH];
-
- if (count >= MAX_LOC_CODE_LENGTH)
- return -EINVAL;
- memcpy(parm, buf, count);
- parm[count] = '\0';
- if (parm[count-1] == '\n')
- parm[count-1] = '\0';
-
- if (bus_find_device(&ibmebus_bus_type, NULL, parm,
- ibmebus_match_helper_loc_code)) {
- printk(KERN_WARNING "%s: loc_code %s has already been probed\n",
- __FUNCTION__, parm);
- return -EINVAL;
- }
+ char *path;
+ ssize_t rc;

- while ((dn = of_find_all_nodes(dn))) {
- loc_code = (char *)get_property(dn, "ibm,loc-code", NULL);
- if (loc_code && (strncmp(loc_code, parm, count) == 0)) {
- dev = ibmebus_register_device_node(dn);
- if (IS_ERR(dev)) {
- of_node_put(dn);
- return PTR_ERR(dev);
- } else
- return count; /* success */
- }
+ path = ibmebus_chomp(buf, count);
+ if (!path)
+ return -ENOMEM;
+
+ if (bus_find_device(&ibmebus_bus_type, NULL, path,
+ ibmebus_match_path)) {
+ printk(KERN_WARNING "%s: %s has already been probed\n",
+ __FUNCTION__, path);
+ rc = -EINVAL;
+ goto out;
+ }
+
+ if ((dn = of_find_node_by_path(path))) {
+ dev = ibmebus_register_device_node(dn);
+ of_node_put(dn);
+ rc = IS_ERR(dev) ? PTR_ERR(dev) : count;
+ } else {
+ printk(KERN_WARNING "%s: no such device node: %s",
+ __FUNCTION__, path);
+ rc = -ENODEV;
}

- /* if we drop out of the loop, the loc code was invalid */
- printk(KERN_WARNING "%s: no device with loc_code %s found\n",
- __FUNCTION__, parm);
- return -ENODEV;
+out:
+ kfree(path);
+ return rc;
}

static ssize_t ibmebus_store_remove(struct bus_type *bus,
const char *buf, size_t count)
{
struct device *dev;
- char parm[MAX_LOC_CODE_LENGTH];
+ char *path;

- if (count >= MAX_LOC_CODE_LENGTH)
- return -EINVAL;
- memcpy(parm, buf, count);
- parm[count] = '\0';
- if (parm[count-1] == '\n')
- parm[count-1] = '\0';
-
- /* The location code is unique, so we will find one device at most */
- if ((dev = bus_find_device(&ibmebus_bus_type, NULL, parm,
- ibmebus_match_helper_loc_code))) {
+ path = ibmebus_chomp(buf, count);
+ if (!path)
+ return -ENOMEM;
+
+ if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
+ ibmebus_match_path))) {
ibmebus_unregister_device(dev);
+
+ kfree(path);
+ return count;
} else {
- printk(KERN_WARNING "%s: loc_code %s not on the bus\n",
- __FUNCTION__, parm);
+ printk(KERN_WARNING "%s: %s not on the bus\n",
+ __FUNCTION__, path);
+
+ kfree(path);
return -ENODEV;
}
-
- return count;
}

static struct bus_attribute ibmebus_bus_attrs[] = {

-
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