2021-08-16 03:44:04

by moyufeng

[permalink] [raw]
Subject: [RFC V4 net-next 1/4] ethtool: add two coalesce attributes for CQE mode

Currently, there many drivers who support CQE mode configuration,
some configure it as a fixed when initialized, some provide an
interface to change it by ethtool private flags. In order make it
more generic, add two new 'ETHTOOL_A_COALESCE_USE_CQE_TX' and
'ETHTOOL_A_COALESCE_USE_CQE_RX' coalesce attributes, then these
parameters can be accessed by ethtool netlink coalesce uAPI.

Signed-off-by: Yufeng Mo <[email protected]>
Signed-off-by: Huazhong Tan <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
---
Documentation/networking/ethtool-netlink.rst | 15 +++++++++++++++
include/linux/ethtool.h | 6 +++++-
include/uapi/linux/ethtool_netlink.h | 2 ++
3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index c86628e..5f62d27 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -939,12 +939,25 @@ Kernel response contents:
``ETHTOOL_A_COALESCE_TX_USECS_HIGH`` u32 delay (us), high Tx
``ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH`` u32 max packets, high Tx
``ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL`` u32 rate sampling interval
+ ``ETHTOOL_A_COALESCE_USE_CQE_TX`` bool timer reset mode, Tx
+ ``ETHTOOL_A_COALESCE_USE_CQE_RX`` bool timer reset mode, Rx
=========================================== ====== =======================

Attributes are only included in reply if their value is not zero or the
corresponding bit in ``ethtool_ops::supported_coalesce_params`` is set (i.e.
they are declared as supported by driver).

+Timer reset mode (``ETHTOOL_A_COALESCE_USE_CQE_TX`` and
+``ETHTOOL_A_COALESCE_USE_CQE_RX``) controls the interaction between packet
+arrival and the various time based delay parameters. By default timers are
+expected to limit the max delay between any packet arrival/departure and a
+corresponding interrupt. In this mode timer should be started by packet
+arrival (sometimes delivery of previous interrupt) and reset when interrupt
+is delivered.
+Setting the appropriate attribute to 1 will enable ``CQE`` mode, where
+each packet event resets the timer. In this mode timer is used to force
+the interrupt if queue goes idle, while busy queues depend on the packet
+limit to trigger interrupts.

COALESCE_SET
============
@@ -977,6 +990,8 @@ Request contents:
``ETHTOOL_A_COALESCE_TX_USECS_HIGH`` u32 delay (us), high Tx
``ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH`` u32 max packets, high Tx
``ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL`` u32 rate sampling interval
+ ``ETHTOOL_A_COALESCE_USE_CQE_TX`` bool timer reset mode, Tx
+ ``ETHTOOL_A_COALESCE_USE_CQE_RX`` bool timer reset mode, Rx
=========================================== ====== =======================

Request is rejected if it attributes declared as unsupported by driver (i.e.
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 4711b96..bad4c7a 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -211,7 +211,9 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 *legacy_u32,
#define ETHTOOL_COALESCE_TX_USECS_HIGH BIT(19)
#define ETHTOOL_COALESCE_TX_MAX_FRAMES_HIGH BIT(20)
#define ETHTOOL_COALESCE_RATE_SAMPLE_INTERVAL BIT(21)
-#define ETHTOOL_COALESCE_ALL_PARAMS GENMASK(21, 0)
+#define ETHTOOL_COALESCE_USE_CQE_RX BIT(22)
+#define ETHTOOL_COALESCE_USE_CQE_TX BIT(23)
+#define ETHTOOL_COALESCE_ALL_PARAMS GENMASK(23, 0)

#define ETHTOOL_COALESCE_USECS \
(ETHTOOL_COALESCE_RX_USECS | ETHTOOL_COALESCE_TX_USECS)
@@ -237,6 +239,8 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 *legacy_u32,
ETHTOOL_COALESCE_RX_USECS_LOW | ETHTOOL_COALESCE_RX_USECS_HIGH | \
ETHTOOL_COALESCE_PKT_RATE_LOW | ETHTOOL_COALESCE_PKT_RATE_HIGH | \
ETHTOOL_COALESCE_RATE_SAMPLE_INTERVAL)
+#define ETHTOOL_COALESCE_USE_CQE \
+ (ETHTOOL_COALESCE_USE_CQE_RX | ETHTOOL_COALESCE_USE_CQE_TX)

#define ETHTOOL_STAT_NOT_SET (~0ULL)

diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index b3b9371..5545f1c 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -377,6 +377,8 @@ enum {
ETHTOOL_A_COALESCE_TX_USECS_HIGH, /* u32 */
ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH, /* u32 */
ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL, /* u32 */
+ ETHTOOL_A_COALESCE_USE_CQE_MODE_TX, /* u8 */
+ ETHTOOL_A_COALESCE_USE_CQE_MODE_RX, /* u8 */

/* add new constants above here */
__ETHTOOL_A_COALESCE_CNT,
--
2.8.1