s390/ccwgroup: exploit ccwdev_by_dev_id

Instead of finding devices via driver_find_device use the bus_find_device
wrapper get_ccwdev_by_dev_id. This allows us to get rid of the ccw_driver
argument of ccwgroup_create_dev and thus simplify the interface.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 30 insertions, 39 deletions

diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 0c7ed30ac87e..c69cee607aed 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -15,10 +15,13 @@
 #include <linux/ctype.h>
 #include <linux/dcache.h>
 
+#include <asm/cio.h>
 #include <asm/ccwdev.h>
 #include <asm/ccwgroup.h>
 
-#define CCW_BUS_ID_SIZE         20
+#include "device.h"
+
+#define CCW_BUS_ID_SIZE         10
 
 /* In Linux 2.4, we had a channel device layer called "chandev"
  * that did all sorts of obscure stuff for networking devices.
@@ -254,9 +257,10 @@ static int __ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
         return 0;
 }
 
-static int __get_next_bus_id(const char **buf, char *bus_id)
+static int __get_next_id(const char **buf, struct ccw_dev_id *id)
 {
-        int rc, len;
+        unsigned int cssid, ssid, devno;
+        int ret = 0, len;
         char *start, *end;
 
         start = (char *)*buf;
@@ -271,50 +275,42 @@ static int __get_next_bus_id(const char **buf, char *bus_id)
                 len = end - start + 1;
                 end++;
         }
-        if (len < CCW_BUS_ID_SIZE) {
-                strlcpy(bus_id, start, len);
-                rc = 0;
+        if (len <= CCW_BUS_ID_SIZE) {
+                if (sscanf(start, "%2x.%1x.%04x", &cssid, &ssid, &devno) != 3)
+                        ret = -EINVAL;
         } else
-                rc = -EINVAL;
-        *buf = end;
-        return rc;
-}
-
-static int __is_valid_bus_id(char bus_id[CCW_BUS_ID_SIZE])
-{
-        int cssid, ssid, devno;
+                ret = -EINVAL;
 
-        /* Must be of form %x.%x.%04x */
-        if (sscanf(bus_id, "%x.%1x.%04x", &cssid, &ssid, &devno) != 3)
-                return 0;
-        return 1;
+        if (!ret) {
+                id->ssid = ssid;
+                id->devno = devno;
+        }
+        *buf = end;
+        return ret;
 }
 
 /**
  * ccwgroup_create_dev() - create and register a ccw group device
  * @parent: parent device for the new device
  * @creator_id: identifier of creating driver
- * @cdrv: ccw driver of slave devices
  * @gdrv: driver for the new group device
  * @num_devices: number of slave devices
  * @buf: buffer containing comma separated bus ids of slave devices
  *
  * Create and register a new ccw group device as a child of @parent. Slave
- * devices are obtained from the list of bus ids given in @buf and must all
- * belong to @cdrv.
+ * devices are obtained from the list of bus ids given in @buf.
  * Returns:
  *  %0 on success and an error code on failure.
  * Context:
  *  non-atomic
  */
 int ccwgroup_create_dev(struct device *parent, unsigned int creator_id,
-                        struct ccw_driver *cdrv, struct ccwgroup_driver *gdrv,
-                        int num_devices, const char *buf)
+                        struct ccwgroup_driver *gdrv, int num_devices,
+                        const char *buf)
 {
         struct ccwgroup_device *gdev;
+        struct ccw_dev_id dev_id;
         int rc, i;
-        char tmp_bus_id[CCW_BUS_ID_SIZE];
-        const char *curr_buf;
 
         gdev = kzalloc(sizeof(*gdev) + num_devices * sizeof(gdev->cdev[0]),
                        GFP_KERNEL);
@@ -334,22 +330,18 @@ int ccwgroup_create_dev(struct device *parent, unsigned int creator_id,
         gdev->dev.release = ccwgroup_release;
         device_initialize(&gdev->dev);
 
-        curr_buf = buf;
-        for (i = 0; i < num_devices && curr_buf; i++) {
-                rc = __get_next_bus_id(&curr_buf, tmp_bus_id);
+        for (i = 0; i < num_devices && buf; i++) {
+                rc = __get_next_id(&buf, &dev_id);
                 if (rc != 0)
                         goto error;
-                if (!__is_valid_bus_id(tmp_bus_id)) {
-                        rc = -EINVAL;
-                        goto error;
-                }
-                gdev->cdev[i] = get_ccwdev_by_busid(cdrv, tmp_bus_id);
+                gdev->cdev[i] = get_ccwdev_by_dev_id(&dev_id);
                 /*
                  * All devices have to be of the same type in
                  * order to be grouped.
                  */
-                if (!gdev->cdev[i]
-                    || gdev->cdev[i]->id.driver_info !=
+                if (!gdev->cdev[i] || !gdev->cdev[i]->drv ||
+                    gdev->cdev[i]->drv != gdev->cdev[0]->drv ||
+                    gdev->cdev[i]->id.driver_info !=
                     gdev->cdev[0]->id.driver_info) {
                         rc = -EINVAL;
                         goto error;
@@ -365,12 +357,12 @@ int ccwgroup_create_dev(struct device *parent, unsigned int creator_id,
                 spin_unlock_irq(gdev->cdev[i]->ccwlock);
         }
         /* Check for sufficient number of bus ids. */
-        if (i < num_devices && !curr_buf) {
+        if (i < num_devices) {
                 rc = -EINVAL;
                 goto error;
         }
         /* Check for trailing stuff. */
-        if (i == num_devices && strlen(curr_buf) > 0) {
+        if (i == num_devices && strlen(buf) > 0) {
                 rc = -EINVAL;
                 goto error;
         }
@@ -430,8 +422,7 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
                                 struct ccw_driver *cdrv, int num_devices,
                                 const char *buf)
 {
-        return ccwgroup_create_dev(root, creator_id, cdrv, NULL,
-                                   num_devices, buf);
+        return ccwgroup_create_dev(root, creator_id, NULL, num_devices, buf);
 }
 EXPORT_SYMBOL(ccwgroup_create_from_string);