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path: root/drivers/s390/cio/device.c
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Diffstat (limited to 'drivers/s390/cio/device.c')
-rw-r--r--drivers/s390/cio/device.c109
1 files changed, 66 insertions, 43 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 646da5640401..688945662c15 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -52,53 +52,81 @@ ccw_bus_match (struct device * dev, struct device_driver * drv)
return 1;
}
-/*
- * Hotplugging interface for ccw devices.
- * Heavily modeled on pci and usb hotplug.
- */
-static int
-ccw_uevent (struct device *dev, char **envp, int num_envp,
- char *buffer, int buffer_size)
+/* Store modalias string delimited by prefix/suffix string into buffer with
+ * specified size. Return length of resulting string (excluding trailing '\0')
+ * even if string doesn't fit buffer (snprintf semantics). */
+static int snprint_alias(char *buf, size_t size, const char *prefix,
+ struct ccw_device_id *id, const char *suffix)
{
- struct ccw_device *cdev = to_ccwdev(dev);
- int i = 0;
- int length = 0;
+ int len;
- if (!cdev)
- return -ENODEV;
+ len = snprintf(buf, size, "%sccw:t%04Xm%02X", prefix, id->cu_type,
+ id->cu_model);
+ if (len > size)
+ return len;
+ buf += len;
+ size -= len;
- /* what we want to pass to /sbin/hotplug */
+ if (id->dev_type != 0)
+ len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
+ id->dev_model, suffix);
+ else
+ len += snprintf(buf, size, "dtdm%s", suffix);
- envp[i++] = buffer;
- length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
- cdev->id.cu_type);
- if ((buffer_size - length <= 0) || (i >= num_envp))
- return -ENOMEM;
- ++length;
- buffer += length;
+ return len;
+}
+/* Set up environment variables for ccw device uevent. Return 0 on success,
+ * non-zero otherwise. */
+static int ccw_uevent(struct device *dev, char **envp, int num_envp,
+ char *buffer, int buffer_size)
+{
+ struct ccw_device *cdev = to_ccwdev(dev);
+ struct ccw_device_id *id = &(cdev->id);
+ int i = 0;
+ int len;
+
+ /* CU_TYPE= */
+ len = snprintf(buffer, buffer_size, "CU_TYPE=%04X", id->cu_type) + 1;
+ if (len > buffer_size || i >= num_envp)
+ return -ENOMEM;
envp[i++] = buffer;
- length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
- cdev->id.cu_model);
- if ((buffer_size - length <= 0) || (i >= num_envp))
+ buffer += len;
+ buffer_size -= len;
+
+ /* CU_MODEL= */
+ len = snprintf(buffer, buffer_size, "CU_MODEL=%02X", id->cu_model) + 1;
+ if (len > buffer_size || i >= num_envp)
return -ENOMEM;
- ++length;
- buffer += length;
+ envp[i++] = buffer;
+ buffer += len;
+ buffer_size -= len;
/* The next two can be zero, that's ok for us */
- envp[i++] = buffer;
- length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
- cdev->id.dev_type);
- if ((buffer_size - length <= 0) || (i >= num_envp))
+ /* DEV_TYPE= */
+ len = snprintf(buffer, buffer_size, "DEV_TYPE=%04X", id->dev_type) + 1;
+ if (len > buffer_size || i >= num_envp)
return -ENOMEM;
- ++length;
- buffer += length;
+ envp[i++] = buffer;
+ buffer += len;
+ buffer_size -= len;
+ /* DEV_MODEL= */
+ len = snprintf(buffer, buffer_size, "DEV_MODEL=%02X",
+ (unsigned char) id->dev_model) + 1;
+ if (len > buffer_size || i >= num_envp)
+ return -ENOMEM;
envp[i++] = buffer;
- length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
- cdev->id.dev_model);
- if ((buffer_size - length <= 0) || (i >= num_envp))
+ buffer += len;
+ buffer_size -= len;
+
+ /* MODALIAS= */
+ len = snprint_alias(buffer, buffer_size, "MODALIAS=", id, "") + 1;
+ if (len > buffer_size || i >= num_envp)
return -ENOMEM;
+ envp[i++] = buffer;
+ buffer += len;
+ buffer_size -= len;
envp[i] = NULL;
@@ -251,16 +279,11 @@ modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
{
struct ccw_device *cdev = to_ccwdev(dev);
struct ccw_device_id *id = &(cdev->id);
- int ret;
+ int len;
- ret = sprintf(buf, "ccw:t%04Xm%02X",
- id->cu_type, id->cu_model);
- if (id->dev_type != 0)
- ret += sprintf(buf + ret, "dt%04Xdm%02X\n",
- id->dev_type, id->dev_model);
- else
- ret += sprintf(buf + ret, "dtdm\n");
- return ret;
+ len = snprint_alias(buf, PAGE_SIZE, "", id, "\n") + 1;
+
+ return len > PAGE_SIZE ? PAGE_SIZE : len;
}
static ssize_t