i40e: queue-specific settings for interrupt moderation

For i40e driver, each vector has its own ITR register. However, there
are no concept of queue-specific settings in the driver proper. Only
global variable is used to store ITR values. That will cause problems
especially when resetting the vector. The specific ITR values could be
lost.
This patch move rx_itr_setting and tx_itr_setting to i40e_ring to store
specific ITR register for each queue.
i40e_get_coalesce and i40e_set_coalesce are also modified accordingly to
support queue-specific settings. To make it compatible with old ethtool,
if user doesn't specify the queue number, i40e_get_coalesce will return
queue 0's value. While i40e_set_coalesce will apply value to all queues.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 56009709528a..cdd5dc00aec5 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -248,6 +248,14 @@ struct i40e_ring {
 	u8 dcb_tc;			/* Traffic class of ring */
 	u8 __iomem *tail;
 
+	/* high bit set means dynamic, use accessor routines to read/write.
+	 * hardware only supports 2us resolution for the ITR registers.
+	 * these values always store the USER setting, and must be converted
+	 * before programming to a register.
+	 */
+	u16 rx_itr_setting;
+	u16 tx_itr_setting;
+
 	u16 count;			/* Number of descriptors */
 	u16 reg_idx;			/* HW register index of the ring */
 	u16 rx_hdr_len;