Merge branch 'ethtool-rssh-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bwh/net-next

Ben Hutchings says:

====================
Pull request: Fixes for new ethtool RSS commands

This addresses several problems I previously identified with the new
ETHTOOL_{G,S}RSSH commands:

1. Missing validation of reserved parameters
2. Vague documentation
3. Use of unnamed magic number
4. No consolidation with existing driver operations

I don't currently have access to suitable network hardware, but have
tested these changes with a dummy driver that can support various
combinations of operations and sizes, together with (a) Debian's ethtool
3.13 (b) ethtool 3.14 with the submitted patch to use ETHTOOL_{G,S}RSSH
and minor adjustment for fixes 1 and 3.

v2: Update RSS operations in vmxnet3 too
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 24 insertions, 25 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 212f537fc686..e658229fee39 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -158,19 +158,16 @@ static inline u32 ethtool_rxfh_indir_default(u32 index, u32 n_rx_rings)
  *	Returns zero if not supported for this specific device.
  * @get_rxfh_indir_size: Get the size of the RX flow hash indirection table.
  *	Returns zero if not supported for this specific device.
- * @get_rxfh_indir: Get the contents of the RX flow hash indirection table.
- *	Will not be called if @get_rxfh_indir_size returns zero.
  * @get_rxfh: Get the contents of the RX flow hash indirection table and hash
  *	key.
- *	Will not be called if @get_rxfh_indir_size and @get_rxfh_key_size
- *	returns zero.
+ *	Will only be called if one or both of @get_rxfh_indir_size and
+ *	@get_rxfh_key_size are implemented and return non-zero.
  *	Returns a negative error code or zero.
- * @set_rxfh_indir: Set the contents of the RX flow hash indirection table.
- *	Will not be called if @get_rxfh_indir_size returns zero.
- * @set_rxfh: Set the contents of the RX flow hash indirection table and
- *	hash key.
- *	Will not be called if @get_rxfh_indir_size and @get_rxfh_key_size
- *	returns zero.
+ * @set_rxfh: Set the contents of the RX flow hash indirection table and/or
+ *	hash key.  In case only the indirection table or hash key is to be
+ *	changed, the other argument will be %NULL.
+ *	Will only be called if one or both of @get_rxfh_indir_size and
+ *	@get_rxfh_key_size are implemented and return non-zero.
  *	Returns a negative error code or zero.
  * @get_channels: Get number of channels.
  * @set_channels: Set number of channels.  Returns a negative error code or
@@ -244,10 +241,9 @@ struct ethtool_ops {
 	int	(*reset)(struct net_device *, u32 *);
 	u32	(*get_rxfh_key_size)(struct net_device *);
 	u32	(*get_rxfh_indir_size)(struct net_device *);
-	int	(*get_rxfh)(struct net_device *, u32 *, u8 *);
-	int	(*set_rxfh)(struct net_device *, u32 *, u8 *);
-	int	(*get_rxfh_indir)(struct net_device *, u32 *);
-	int	(*set_rxfh_indir)(struct net_device *, const u32 *);
+	int	(*get_rxfh)(struct net_device *, u32 *indir, u8 *key);
+	int	(*set_rxfh)(struct net_device *, const u32 *indir,
+			    const u8 *key);
 	void	(*get_channels)(struct net_device *, struct ethtool_channels *);
 	int	(*set_channels)(struct net_device *, struct ethtool_channels *);
 	int	(*get_dump_flag)(struct net_device *, struct ethtool_dump *);
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index d47d31d6fa0e..e3c7a719c76b 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -850,21 +850,23 @@ struct ethtool_rxfh_indir {
  * struct ethtool_rxfh - command to get/set RX flow hash indir or/and hash key.
  * @cmd: Specific command number - %ETHTOOL_GRSSH or %ETHTOOL_SRSSH
  * @rss_context: RSS context identifier.
- * @indir_size: On entry, the array size of the user buffer, which may be zero.
- *		On return from %ETHTOOL_GRSSH, the array size of the hardware
- *		indirection table.
- * @key_size:	On entry, the array size of the user buffer in bytes,
- *		which may be zero.
- *		On return from %ETHTOOL_GRSSH, the size of the RSS hash key.
+ * @indir_size: On entry, the array size of the user buffer for the
+ *	indirection table, which may be zero, or (for %ETHTOOL_SRSSH),
+ *	%ETH_RXFH_INDIR_NO_CHANGE.  On return from %ETHTOOL_GRSSH,
+ *	the array size of the hardware indirection table.
+ * @key_size: On entry, the array size of the user buffer for the hash key,
+ *	which may be zero.  On return from %ETHTOOL_GRSSH, the size of the
+ *	hardware hash key.
  * @rsvd:	Reserved for future extensions.
  * @rss_config: RX ring/queue index for each hash value i.e., indirection table
- *		of size @indir_size followed by hash key of size @key_size.
+ *	of @indir_size __u32 elements, followed by hash key of @key_size
+ *	bytes.
  *
  * For %ETHTOOL_GRSSH, a @indir_size and key_size of zero means that only the
- * size should be returned.  For %ETHTOOL_SRSSH, a @indir_size of 0xDEADBEEF
- * means that indir table setting is not requested and a @indir_size of zero
- * means the indir table should be reset to default values.  This last feature
- * is not supported by the original implementations.
+ * size should be returned.  For %ETHTOOL_SRSSH, an @indir_size of
+ * %ETH_RXFH_INDIR_NO_CHANGE means that indir table setting is not requested
+ * and a @indir_size of zero means the indir table should be reset to default
+ * values.
  */
 struct ethtool_rxfh {
 	__u32   cmd;
@@ -874,6 +876,7 @@ struct ethtool_rxfh {
 	__u32	rsvd[2];
 	__u32   rss_config[0];
 };
+#define ETH_RXFH_INDIR_NO_CHANGE	0xffffffff
 
 /**
  * struct ethtool_rx_ntuple_flow_spec - specification for RX flow filter