ethtool: Added support for FW dump

Added code to take FW dump via ethtool. Dump level can be controlled via setting the
dump flag. A get function is provided to query the current setting of the dump flag.
Dump data is obtained from the driver via a separate get function.

Changes from v3:
Fixed buffer length issue in ethtool_get_dump_data function.
Updated kernel doc for ethtool_dump struct and get_dump_flag function.

Changes from v2:
Provided separate commands for get flag and data.
Check for minimum of the two buffer length obtained via ethtool and driver and
use that for dump buffer
Pass up the driver return error codes up to the caller.
Added kernel doc comments.

Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 90 insertions, 0 deletions

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index b8c2b10f397a..b8c2bcfee6af 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1823,6 +1823,87 @@ static noinline_for_stack int ethtool_flash_device(struct net_device *dev,
         return dev->ethtool_ops->flash_device(dev, &efl);
 }
 
+static int ethtool_set_dump(struct net_device *dev,
+                        void __user *useraddr)
+{
+        struct ethtool_dump dump;
+
+        if (!dev->ethtool_ops->set_dump)
+                return -EOPNOTSUPP;
+
+        if (copy_from_user(&dump, useraddr, sizeof(dump)))
+                return -EFAULT;
+
+        return dev->ethtool_ops->set_dump(dev, &dump);
+}
+
+static int ethtool_get_dump_flag(struct net_device *dev,
+                                void __user *useraddr)
+{
+        int ret;
+        struct ethtool_dump dump;
+        const struct ethtool_ops *ops = dev->ethtool_ops;
+
+        if (!dev->ethtool_ops->get_dump_flag)
+                return -EOPNOTSUPP;
+
+        if (copy_from_user(&dump, useraddr, sizeof(dump)))
+                return -EFAULT;
+
+        ret = ops->get_dump_flag(dev, &dump);
+        if (ret)
+                return ret;
+
+        if (copy_to_user(useraddr, &dump, sizeof(dump)))
+                return -EFAULT;
+        return 0;
+}
+
+static int ethtool_get_dump_data(struct net_device *dev,
+                                void __user *useraddr)
+{
+        int ret;
+        __u32 len;
+        struct ethtool_dump dump, tmp;
+        const struct ethtool_ops *ops = dev->ethtool_ops;
+        void *data = NULL;
+
+        if (!dev->ethtool_ops->get_dump_data ||
+                !dev->ethtool_ops->get_dump_flag)
+                return -EOPNOTSUPP;
+
+        if (copy_from_user(&dump, useraddr, sizeof(dump)))
+                return -EFAULT;
+
+        memset(&tmp, 0, sizeof(tmp));
+        tmp.cmd = ETHTOOL_GET_DUMP_FLAG;
+        ret = ops->get_dump_flag(dev, &tmp);
+        if (ret)
+                return ret;
+
+        len = (tmp.len > dump.len) ? dump.len : tmp.len;
+        if (!len)
+                return -EFAULT;
+
+        data = vzalloc(tmp.len);
+        if (!data)
+                return -ENOMEM;
+        ret = ops->get_dump_data(dev, &dump, data);
+        if (ret)
+                goto out;
+
+        if (copy_to_user(useraddr, &dump, sizeof(dump))) {
+                ret = -EFAULT;
+                goto out;
+        }
+        useraddr += offsetof(struct ethtool_dump, data);
+        if (copy_to_user(useraddr, data, len))
+                ret = -EFAULT;
+out:
+        vfree(data);
+        return ret;
+}
+
 /* The main entry point in this file.  Called from net/core/dev.c */
 
 int dev_ethtool(struct net *net, struct ifreq *ifr)
@@ -2039,6 +2120,15 @@ int dev_ethtool(struct net *net, struct ifreq *ifr)
         case ETHTOOL_SCHANNELS:
                 rc = ethtool_set_channels(dev, useraddr);
                 break;
+        case ETHTOOL_SET_DUMP:
+                rc = ethtool_set_dump(dev, useraddr);
+                break;
+        case ETHTOOL_GET_DUMP_FLAG:
+                rc = ethtool_get_dump_flag(dev, useraddr);
+                break;
+        case ETHTOOL_GET_DUMP_DATA:
+                rc = ethtool_get_dump_data(dev, useraddr);
+                break;
         default:
                 rc = -EOPNOTSUPP;
         }