Merge branch 'ethtool-perqueue-params'

Kan Liang says:

====================
ethtool per queue parameters support

Modern network interface controllers usually support multiple receive
and transmit queues. Each queue may have its own parameters. For
example, Intel XL710/X710 hardware supports per queue interrupt
moderation. However, current ethtool does not support per queue
parameters option. User has to set parameters for the whole NIC.
This series extends ethtool to support per queue parameters option.

Since the support of per queue parameters vary with different cards,
it is impossible to address all cards in one patch. This series only
supports per queue coalesce options on i40e driver. The framework used
in the patch can be easily extended to other cards and parameters.

The lib bitmap needs to be extended to facilitate exchanging queue bitmaps
between user space and kernel space. Two patches from David's latest V8
patch series are also cited in this series. You may refer to
https://lkml.org/lkml/2016/2/9/919 for more details.

Changes since V6:
 - Rebase on commit 76d13b568776. Did minor change in patch 6.

Changes since V5:
 - Add test_bitmap.c and bitmap.sh in the series. They are forgot
   to be added previously.
 - Update the first two patches to David's latest V8 version. The changes
   include
      - bitmap u32 API returns number of bits copied, unit tests updated
      - module_exit in test_bitmap
 - Also change the mode of bitmap.sh to 755 according to Ben's suggestion

Changes since V4:
 - Modify set/get_per_queue_coalesce function description
 - Change the queue number to be u32
 - Correct an error of calculating coalesce backup buffer address
 - Rename queue_num to n_queues
 - Don't log error message in __i40e_get_coalesce

Changes since V3:
 - Based on David's lib bitmap.
 - ETHTOOL_PERQUEUE should be handled before the containing switch
 - Make the rollback code unconditional
 - some minor changes according to Ben's feedback

Changes since V2:
 - Add queue-specific settings for interrupt moderation in i40e

Changes since V1:
 - Checking the sub-command number to determine whether the command
   requires CAP_NET_ADMIN
 - Refine the struct ethtool_per_queue_op and improve the comments
 - Use bitmap functions to parse queue mask
 - Improve comments
 - Use bitmap functions to parse queue mask
 - Improve comments
 - Add rollback support
 - Correct the way to find the vector for specific queue.
====================

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

2 files changed, 24 insertions, 1 deletions

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 9653fdb76a42..e9b0b9ab07e5 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -59,6 +59,8 @@
  * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
  * bitmap_release_region(bitmap, pos, order)	Free specified bit region
  * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
+ * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words)
+ * bitmap_to_u32array(buf, nwords, src, nbits)	*buf = *dst (nwords 32b words)
  */
 
 /*
@@ -163,6 +165,14 @@ extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
+extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
+					 unsigned int nbits,
+					 const u32 *buf,
+					 unsigned int nwords);
+extern unsigned int bitmap_to_u32array(u32 *buf,
+				       unsigned int nwords,
+				       const unsigned long *bitmap,
+				       unsigned int nbits);
 #ifdef __BIG_ENDIAN
 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
 #else
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 653dc9c4ebac..472d7d7b01c2 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -201,6 +201,16 @@ static inline u32 ethtool_rxfh_indir_default(u32 index, u32 n_rx_rings)
  * @get_module_eeprom: Get the eeprom information from the plug-in module
  * @get_eee: Get Energy-Efficient (EEE) supported and status.
  * @set_eee: Set EEE status (enable/disable) as well as LPI timers.
+ * @get_per_queue_coalesce: Get interrupt coalescing parameters per queue.
+ *	It must check that the given queue number is valid. If neither a RX nor
+ *	a TX queue has this number, return -EINVAL. If only a RX queue or a TX
+ *	queue has this number, set the inapplicable fields to ~0 and return 0.
+ *	Returns a negative error code or zero.
+ * @set_per_queue_coalesce: Set interrupt coalescing parameters per queue.
+ *	It must check that the given queue number is valid. If neither a RX nor
+ *	a TX queue has this number, return -EINVAL. If only a RX queue or a TX
+ *	queue has this number, ignore the inapplicable fields.
+ *	Returns a negative error code or zero.
  *
  * All operations are optional (i.e. the function pointer may be set
  * to %NULL) and callers must take this into account.  Callers must
@@ -279,7 +289,10 @@ struct ethtool_ops {
 			       const struct ethtool_tunable *, void *);
 	int	(*set_tunable)(struct net_device *,
 			       const struct ethtool_tunable *, const void *);
-
+	int	(*get_per_queue_coalesce)(struct net_device *, u32,
+					  struct ethtool_coalesce *);
+	int	(*set_per_queue_coalesce)(struct net_device *, u32,
+					  struct ethtool_coalesce *);
 
 };
 #endif /* _LINUX_ETHTOOL_H */