[PATCH net-next v2 10/15] ethtool: provide ring sizes with RINGS_GET request

From: Michal Kubecek
Date: Thu Mar 12 2020 - 16:08:29 EST


Implement RINGS_GET request to get ring sizes of a network device. These
are traditionally available via ETHTOOL_GRINGPARAM ioctl request.

Omit attributes for ring types which are not supported by driver or device
(zero reported for maximum).

v2: (all suggested by Jakub Kicinski)
- minor cleanup in rings_prepare_data()
- more descriptive rings_reply_size()
- omit attributes with zero max size

Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
---
Documentation/networking/ethtool-netlink.rst | 30 +++++-
include/uapi/linux/ethtool_netlink.h | 21 ++++
net/ethtool/Makefile | 2 +-
net/ethtool/netlink.c | 8 ++
net/ethtool/netlink.h | 1 +
net/ethtool/rings.c | 108 +++++++++++++++++++
6 files changed, 168 insertions(+), 2 deletions(-)
create mode 100644 net/ethtool/rings.c

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index e553112fa2d7..798c2f97d89b 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -193,6 +193,7 @@ Userspace to kernel:
``ETHTOOL_MSG_FEATURES_SET`` set device features
``ETHTOOL_MSG_PRIVFLAGS_GET`` get private flags
``ETHTOOL_MSG_PRIVFLAGS_SET`` set private flags
+ ``ETHTOOL_MSG_RINGS_GET`` get ring sizes
===================================== ================================

Kernel to userspace:
@@ -213,6 +214,7 @@ Kernel to userspace:
``ETHTOOL_MSG_FEATURES_NTF`` netdev features notification
``ETHTOOL_MSG_PRIVFLAGS_GET_REPLY`` private flags
``ETHTOOL_MSG_PRIVFLAGS_NTF`` private flags
+ ``ETHTOOL_MSG_RINGS_GET_REPLY`` ring sizes
===================================== =================================

``GET`` requests are sent by userspace applications to retrieve device
@@ -645,6 +647,32 @@ Request contents:
modify only values of some of them.


+RINGS_GET
+=========
+
+Gets ring sizes like ``ETHTOOL_GRINGPARAM`` ioctl request.
+
+Request contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_RINGS_HEADER`` nested request header
+ ==================================== ====== ==========================
+
+Kernel response contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_RINGS_HEADER`` nested reply header
+ ``ETHTOOL_A_RINGS_RX_MAX`` u32 max size of RX ring
+ ``ETHTOOL_A_RINGS_RX_MINI_MAX`` u32 max size of RX mini ring
+ ``ETHTOOL_A_RINGS_RX_JUMBO_MAX`` u32 max size of RX jumbo ring
+ ``ETHTOOL_A_RINGS_TX_MAX`` u32 max size of TX ring
+ ``ETHTOOL_A_RINGS_RX`` u32 size of RX ring
+ ``ETHTOOL_A_RINGS_RX_MINI`` u32 size of RX mini ring
+ ``ETHTOOL_A_RINGS_RX_JUMBO`` u32 size of RX jumbo ring
+ ``ETHTOOL_A_RINGS_TX`` u32 size of TX ring
+ ==================================== ====== ==========================
+
+
Request translation
===================

@@ -671,7 +699,7 @@ have their netlink replacement yet.
``ETHTOOL_SEEPROM`` n/a
``ETHTOOL_GCOALESCE`` n/a
``ETHTOOL_SCOALESCE`` n/a
- ``ETHTOOL_GRINGPARAM`` n/a
+ ``ETHTOOL_GRINGPARAM`` ``ETHTOOL_MSG_RINGS_GET``
``ETHTOOL_SRINGPARAM`` n/a
``ETHTOOL_GPAUSEPARAM`` n/a
``ETHTOOL_SPAUSEPARAM`` n/a
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 7f23a7f0fca1..7cd220f8cf73 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -28,6 +28,7 @@ enum {
ETHTOOL_MSG_FEATURES_SET,
ETHTOOL_MSG_PRIVFLAGS_GET,
ETHTOOL_MSG_PRIVFLAGS_SET,
+ ETHTOOL_MSG_RINGS_GET,

/* add new constants above here */
__ETHTOOL_MSG_USER_CNT,
@@ -52,6 +53,7 @@ enum {
ETHTOOL_MSG_FEATURES_NTF,
ETHTOOL_MSG_PRIVFLAGS_GET_REPLY,
ETHTOOL_MSG_PRIVFLAGS_NTF,
+ ETHTOOL_MSG_RINGS_GET_REPLY,

/* add new constants above here */
__ETHTOOL_MSG_KERNEL_CNT,
@@ -264,6 +266,25 @@ enum {
ETHTOOL_A_PRIVFLAGS_MAX = __ETHTOOL_A_PRIVFLAGS_CNT - 1
};

+/* RINGS */
+
+enum {
+ ETHTOOL_A_RINGS_UNSPEC,
+ ETHTOOL_A_RINGS_HEADER, /* nest - _A_HEADER_* */
+ ETHTOOL_A_RINGS_RX_MAX, /* u32 */
+ ETHTOOL_A_RINGS_RX_MINI_MAX, /* u32 */
+ ETHTOOL_A_RINGS_RX_JUMBO_MAX, /* u32 */
+ ETHTOOL_A_RINGS_TX_MAX, /* u32 */
+ ETHTOOL_A_RINGS_RX, /* u32 */
+ ETHTOOL_A_RINGS_RX_MINI, /* u32 */
+ ETHTOOL_A_RINGS_RX_JUMBO, /* u32 */
+ ETHTOOL_A_RINGS_TX, /* u32 */
+
+ /* add new constants above here */
+ __ETHTOOL_A_RINGS_CNT,
+ ETHTOOL_A_RINGS_MAX = (__ETHTOOL_A_RINGS_CNT - 1)
+};
+
/* generic netlink info */
#define ETHTOOL_GENL_NAME "ethtool"
#define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 58708bcc2968..b48b70ef4ed0 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -5,4 +5,4 @@ obj-y += ioctl.o common.o
obj-$(CONFIG_ETHTOOL_NETLINK) += ethtool_nl.o

ethtool_nl-y := netlink.o bitset.o strset.o linkinfo.o linkmodes.o \
- linkstate.o debug.o wol.o features.o privflags.o
+ linkstate.o debug.o wol.o features.o privflags.o rings.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index dec82b0b80bd..0dc25a490450 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -217,6 +217,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
[ETHTOOL_MSG_WOL_GET] = &ethnl_wol_request_ops,
[ETHTOOL_MSG_FEATURES_GET] = &ethnl_features_request_ops,
[ETHTOOL_MSG_PRIVFLAGS_GET] = &ethnl_privflags_request_ops,
+ [ETHTOOL_MSG_RINGS_GET] = &ethnl_rings_request_ops,
};

static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -748,6 +749,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_set_privflags,
},
+ {
+ .cmd = ETHTOOL_MSG_RINGS_GET,
+ .doit = ethnl_default_doit,
+ .start = ethnl_default_start,
+ .dumpit = ethnl_default_dumpit,
+ .done = ethnl_default_done,
+ },
};

static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index ca789f587ef3..01761932ed15 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -339,6 +339,7 @@ extern const struct ethnl_request_ops ethnl_debug_request_ops;
extern const struct ethnl_request_ops ethnl_wol_request_ops;
extern const struct ethnl_request_ops ethnl_features_request_ops;
extern const struct ethnl_request_ops ethnl_privflags_request_ops;
+extern const struct ethnl_request_ops ethnl_rings_request_ops;

int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);
diff --git a/net/ethtool/rings.c b/net/ethtool/rings.c
new file mode 100644
index 000000000000..d3129d8a252d
--- /dev/null
+++ b/net/ethtool/rings.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "netlink.h"
+#include "common.h"
+
+struct rings_req_info {
+ struct ethnl_req_info base;
+};
+
+struct rings_reply_data {
+ struct ethnl_reply_data base;
+ struct ethtool_ringparam ringparam;
+};
+
+#define RINGS_REPDATA(__reply_base) \
+ container_of(__reply_base, struct rings_reply_data, base)
+
+static const struct nla_policy
+rings_get_policy[ETHTOOL_A_RINGS_MAX + 1] = {
+ [ETHTOOL_A_RINGS_UNSPEC] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_HEADER] = { .type = NLA_NESTED },
+ [ETHTOOL_A_RINGS_RX_MAX] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_RX_MINI_MAX] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_RX_JUMBO_MAX] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_TX_MAX] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_RX] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_RX_MINI] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_RX_JUMBO] = { .type = NLA_REJECT },
+ [ETHTOOL_A_RINGS_TX] = { .type = NLA_REJECT },
+};
+
+static int rings_prepare_data(const struct ethnl_req_info *req_base,
+ struct ethnl_reply_data *reply_base,
+ struct genl_info *info)
+{
+ struct rings_reply_data *data = RINGS_REPDATA(reply_base);
+ struct net_device *dev = reply_base->dev;
+ int ret;
+
+ if (!dev->ethtool_ops->get_ringparam)
+ return -EOPNOTSUPP;
+ ret = ethnl_ops_begin(dev);
+ if (ret < 0)
+ return ret;
+ dev->ethtool_ops->get_ringparam(dev, &data->ringparam);
+ ethnl_ops_complete(dev);
+
+ return 0;
+}
+
+static int rings_reply_size(const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ return nla_total_size(sizeof(u32)) + /* _RINGS_RX_MAX */
+ nla_total_size(sizeof(u32)) + /* _RINGS_RX_MINI_MAX */
+ nla_total_size(sizeof(u32)) + /* _RINGS_RX_JUMBO_MAX */
+ nla_total_size(sizeof(u32)) + /* _RINGS_TX_MAX */
+ nla_total_size(sizeof(u32)) + /* _RINGS_RX */
+ nla_total_size(sizeof(u32)) + /* _RINGS_RX_MINI */
+ nla_total_size(sizeof(u32)) + /* _RINGS_RX_JUMBO */
+ nla_total_size(sizeof(u32)); /* _RINGS_TX */
+}
+
+static int rings_fill_reply(struct sk_buff *skb,
+ const struct ethnl_req_info *req_base,
+ const struct ethnl_reply_data *reply_base)
+{
+ const struct rings_reply_data *data = RINGS_REPDATA(reply_base);
+ const struct ethtool_ringparam *ringparam = &data->ringparam;
+
+ if ((ringparam->rx_max_pending &&
+ (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_MAX,
+ ringparam->rx_max_pending) ||
+ nla_put_u32(skb, ETHTOOL_A_RINGS_RX,
+ ringparam->rx_pending))) ||
+ (ringparam->rx_mini_max_pending &&
+ (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_MINI_MAX,
+ ringparam->rx_mini_max_pending) ||
+ nla_put_u32(skb, ETHTOOL_A_RINGS_RX_MINI,
+ ringparam->rx_mini_pending))) ||
+ (ringparam->rx_jumbo_max_pending &&
+ (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_JUMBO_MAX,
+ ringparam->rx_jumbo_max_pending) ||
+ nla_put_u32(skb, ETHTOOL_A_RINGS_RX_JUMBO,
+ ringparam->rx_jumbo_pending))) ||
+ (ringparam->tx_max_pending &&
+ (nla_put_u32(skb, ETHTOOL_A_RINGS_TX_MAX,
+ ringparam->tx_max_pending) ||
+ nla_put_u32(skb, ETHTOOL_A_RINGS_TX,
+ ringparam->tx_pending))))
+ return -EMSGSIZE;
+
+ return 0;
+}
+
+const struct ethnl_request_ops ethnl_rings_request_ops = {
+ .request_cmd = ETHTOOL_MSG_RINGS_GET,
+ .reply_cmd = ETHTOOL_MSG_RINGS_GET_REPLY,
+ .hdr_attr = ETHTOOL_A_RINGS_HEADER,
+ .max_attr = ETHTOOL_A_RINGS_MAX,
+ .req_info_size = sizeof(struct rings_req_info),
+ .reply_data_size = sizeof(struct rings_reply_data),
+ .request_policy = rings_get_policy,
+
+ .prepare_data = rings_prepare_data,
+ .reply_size = rings_reply_size,
+ .fill_reply = rings_fill_reply,
+};
--
2.25.1