ethtool: Add support for configuring tx_push_buf_len

This attribute, which is part of ethtool's ring param configuration allows the user to specify the maximum number of the packet's payload that can be written directly to the device. Example usage: # ethtool -G [interface] tx-push-buf-len [number of bytes]

Shay Agroskin committed 3 years ago

Commit 233eb4e1 parent 3e4d5ba6 files · +84 −23Browse files

Unified · Split

6 files

Documentation/netlink/specs/ethtool.yaml +8 −0
Documentation/networking/ethtool-netlink.rst +31 −16
include/linux/ethtool.h +10 −4
include/uapi/linux/ethtool_netlink.h +2 −0
net/ethtool/netlink.h +1 −1
net/ethtool/rings.c +32 −2

Documentation/netlink/specs/ethtool.yaml+8−0

@@ -165,6 +165,12 @@ attribute-sets: · 164 unmodified lines
165	165	-
166	166	name: rx-push
167	167	type: u8
	168	+ -
	169	+ name: tx-push-buf-len
	170	+ type: u32
	171	+ -
	172	+ name: tx-push-buf-len-max
	173	+ type: u32
168	174
169	175	-
170	176	name: mm-stat
@@ -311,6 +317,8 @@ operations: · 140 unmodified lines
311	317	- cqe-size
312	318	- tx-push
313	319	- rx-push
	320	+ - tx-push-buf-len
	321	+ - tx-push-buf-len-max
314	322	dump: *ring-get-op
315	323	-
316	324	name: rings-set

Documentation/networking/ethtool-netlink.rst+31−16

@@ -860,22 +860,24 @@ Request contents: · 859 unmodified lines
860	860
861	861	Kernel response contents:
862	862
863		− ==================================== ====== ===========================
864		− ``ETHTOOL_A_RINGS_HEADER`` nested reply header
865		− ``ETHTOOL_A_RINGS_RX_MAX`` u32 max size of RX ring
866		− ``ETHTOOL_A_RINGS_RX_MINI_MAX`` u32 max size of RX mini ring
867		− ``ETHTOOL_A_RINGS_RX_JUMBO_MAX`` u32 max size of RX jumbo ring
868		− ``ETHTOOL_A_RINGS_TX_MAX`` u32 max size of TX ring
869		− ``ETHTOOL_A_RINGS_RX`` u32 size of RX ring
870		− ``ETHTOOL_A_RINGS_RX_MINI`` u32 size of RX mini ring
871		− ``ETHTOOL_A_RINGS_RX_JUMBO`` u32 size of RX jumbo ring
872		− ``ETHTOOL_A_RINGS_TX`` u32 size of TX ring
873		− ``ETHTOOL_A_RINGS_RX_BUF_LEN`` u32 size of buffers on the ring
874		− ``ETHTOOL_A_RINGS_TCP_DATA_SPLIT`` u8 TCP header / data split
875		− ``ETHTOOL_A_RINGS_CQE_SIZE`` u32 Size of TX/RX CQE
876		− ``ETHTOOL_A_RINGS_TX_PUSH`` u8 flag of TX Push mode
877		− ``ETHTOOL_A_RINGS_RX_PUSH`` u8 flag of RX Push mode
878		− ==================================== ====== ===========================
	863	+ ======================================= ====== ===========================
	864	+ ``ETHTOOL_A_RINGS_HEADER`` nested reply header
	865	+ ``ETHTOOL_A_RINGS_RX_MAX`` u32 max size of RX ring
	866	+ ``ETHTOOL_A_RINGS_RX_MINI_MAX`` u32 max size of RX mini ring
	867	+ ``ETHTOOL_A_RINGS_RX_JUMBO_MAX`` u32 max size of RX jumbo ring
	868	+ ``ETHTOOL_A_RINGS_TX_MAX`` u32 max size of TX ring
	869	+ ``ETHTOOL_A_RINGS_RX`` u32 size of RX ring
	870	+ ``ETHTOOL_A_RINGS_RX_MINI`` u32 size of RX mini ring
	871	+ ``ETHTOOL_A_RINGS_RX_JUMBO`` u32 size of RX jumbo ring
	872	+ ``ETHTOOL_A_RINGS_TX`` u32 size of TX ring
	873	+ ``ETHTOOL_A_RINGS_RX_BUF_LEN`` u32 size of buffers on the ring
	874	+ ``ETHTOOL_A_RINGS_TCP_DATA_SPLIT`` u8 TCP header / data split
	875	+ ``ETHTOOL_A_RINGS_CQE_SIZE`` u32 Size of TX/RX CQE
	876	+ ``ETHTOOL_A_RINGS_TX_PUSH`` u8 flag of TX Push mode
	877	+ ``ETHTOOL_A_RINGS_RX_PUSH`` u8 flag of RX Push mode
	878	+ ``ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN`` u32 size of TX push buffer
	879	+ ``ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX`` u32 max size of TX push buffer
	880	+ ======================================= ====== ===========================
879	881
880	882	``ETHTOOL_A_RINGS_TCP_DATA_SPLIT`` indicates whether the device is usable with
881	883	page-flipping TCP zero-copy receive (``getsockopt(TCP_ZEROCOPY_RECEIVE)``).
@@ -891,6 +893,18 @@ through MMIO writes, thus reducing the latency. However, enabling this feature · 9 unmodified lines
891	893	may increase the CPU cost. Drivers may enforce additional per-packet
892	894	eligibility checks (e.g. on packet size).
893	895
	896	+``ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN`` specifies the maximum number of bytes of a
	897	+transmitted packet a driver can push directly to the underlying device
	898	+('push' mode). Pushing some of the payload bytes to the device has the
	899	+advantages of reducing latency for small packets by avoiding DMA mapping (same
	900	+as ``ETHTOOL_A_RINGS_TX_PUSH`` parameter) as well as allowing the underlying
	901	+device to process packet headers ahead of fetching its payload.
	902	+This can help the device to make fast actions based on the packet's headers.
	903	+This is similar to the "tx-copybreak" parameter, which copies the packet to a
	904	+preallocated DMA memory area instead of mapping new memory. However,
	905	+tx-push-buff parameter copies the packet directly to the device to allow the
	906	+device to take faster actions on the packet.
	907	+
894	908	RINGS_SET
895	909	=========
896	910
@@ -908,6 +922,7 @@ Request contents: · 11 unmodified lines
908	922	``ETHTOOL_A_RINGS_CQE_SIZE`` u32 Size of TX/RX CQE
909	923	``ETHTOOL_A_RINGS_TX_PUSH`` u8 flag of TX Push mode
910	924	``ETHTOOL_A_RINGS_RX_PUSH`` u8 flag of RX Push mode
	925	+ ``ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN`` u32 size of TX push buffer
911	926	==================================== ====== ===========================
912	927
913	928	Kernel checks that requested ring sizes do not exceed limits reported by

include/linux/ethtool.h+10−4

@@ -75,6 +75,8 @@ enum { · 74 unmodified lines
75	75	* @tx_push: The flag of tx push mode
76	76	* @rx_push: The flag of rx push mode
77	77	* @cqe_size: Size of TX/RX completion queue event
	78	+ * @tx_push_buf_len: Size of TX push buffer
	79	+ * @tx_push_buf_max_len: Maximum allowed size of TX push buffer
78	80	*/
79	81	struct kernel_ethtool_ringparam {
80	82	u32 rx_buf_len;
@@ -82,6 +84,8 @@ struct kernel_ethtool_ringparam { · 1 unmodified line
82	84	u8 tx_push;
83	85	u8 rx_push;
84	86	u32 cqe_size;
	87	+ u32 tx_push_buf_len;
	88	+ u32 tx_push_buf_max_len;
85	89	};
86	90
87	91	/**
@@ -90,12 +94,14 @@ struct kernel_ethtool_ringparam { · 2 unmodified lines
90	94	* @ETHTOOL_RING_USE_CQE_SIZE: capture for setting cqe_size
91	95	* @ETHTOOL_RING_USE_TX_PUSH: capture for setting tx_push
92	96	* @ETHTOOL_RING_USE_RX_PUSH: capture for setting rx_push
	97	+ * @ETHTOOL_RING_USE_TX_PUSH_BUF_LEN: capture for setting tx_push_buf_len
93	98	*/
94	99	enum ethtool_supported_ring_param {
95		− ETHTOOL_RING_USE_RX_BUF_LEN = BIT(0),
96		− ETHTOOL_RING_USE_CQE_SIZE = BIT(1),
97		− ETHTOOL_RING_USE_TX_PUSH = BIT(2),
98		− ETHTOOL_RING_USE_RX_PUSH = BIT(3),
	100	+ ETHTOOL_RING_USE_RX_BUF_LEN = BIT(0),
	101	+ ETHTOOL_RING_USE_CQE_SIZE = BIT(1),
	102	+ ETHTOOL_RING_USE_TX_PUSH = BIT(2),
	103	+ ETHTOOL_RING_USE_RX_PUSH = BIT(3),
	104	+ ETHTOOL_RING_USE_TX_PUSH_BUF_LEN = BIT(4),
99	105	};
100	106
101	107	#define __ETH_RSS_HASH_BIT(bit) ((u32)1 << (bit))

include/uapi/linux/ethtool_netlink.h+2−0

@@ -357,6 +357,8 @@ enum { · 356 unmodified lines
357	357	ETHTOOL_A_RINGS_CQE_SIZE, /* u32 */
358	358	ETHTOOL_A_RINGS_TX_PUSH, /* u8 */
359	359	ETHTOOL_A_RINGS_RX_PUSH, /* u8 */
	360	+ ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN, /* u32 */
	361	+ ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX, /* u32 */
360	362
361	363	/* add new constants above here */
362	364	__ETHTOOL_A_RINGS_CNT,

net/ethtool/netlink.h+1−1

@@ -413,7 +413,7 @@ extern const struct nla_policy ethnl_features_set_policy[ETHTOOL_A_FEATURES_WANT · 412 unmodified lines
413	413	extern const struct nla_policy ethnl_privflags_get_policy[ETHTOOL_A_PRIVFLAGS_HEADER + 1];
414	414	extern const struct nla_policy ethnl_privflags_set_policy[ETHTOOL_A_PRIVFLAGS_FLAGS + 1];
415	415	extern const struct nla_policy ethnl_rings_get_policy[ETHTOOL_A_RINGS_HEADER + 1];
416		−extern const struct nla_policy ethnl_rings_set_policy[ETHTOOL_A_RINGS_RX_PUSH + 1];
	416	+extern const struct nla_policy ethnl_rings_set_policy[ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX + 1];
417	417	extern const struct nla_policy ethnl_channels_get_policy[ETHTOOL_A_CHANNELS_HEADER + 1];
418	418	extern const struct nla_policy ethnl_channels_set_policy[ETHTOOL_A_CHANNELS_COMBINED_COUNT + 1];
419	419	extern const struct nla_policy ethnl_coalesce_get_policy[ETHTOOL_A_COALESCE_HEADER + 1];

net/ethtool/rings.c+32−2

@@ -11,6 +11,7 @@ struct rings_reply_data { · 10 unmodified lines
11	11	struct ethnl_reply_data base;
12	12	struct ethtool_ringparam ringparam;
13	13	struct kernel_ethtool_ringparam kernel_ringparam;
	14	+ u32 supported_ring_params;
14	15	};
15	16
16	17	#define RINGS_REPDATA(__reply_base) \
@@ -32,6 +33,8 @@ static int rings_prepare_data(const struct ethnl_req_info *req_base, · 15 unmodified lines
32	33
33	34	if (!dev->ethtool_ops->get_ringparam)
34	35	return -EOPNOTSUPP;
	36	+
	37	+ data->supported_ring_params = dev->ethtool_ops->supported_ring_params;
35	38	ret = ethnl_ops_begin(dev);
36	39	if (ret < 0)
37	40	return ret;
@@ -57,7 +60,9 @@ static int rings_reply_size(const struct ethnl_req_info *req_base, · 19 unmodified lines
57	60	nla_total_size(sizeof(u8)) + /* _RINGS_TCP_DATA_SPLIT */
58	61	nla_total_size(sizeof(u32) + /* _RINGS_CQE_SIZE */
59	62	nla_total_size(sizeof(u8)) + /* _RINGS_TX_PUSH */
60		− nla_total_size(sizeof(u8))); /* _RINGS_RX_PUSH */
	63	+ nla_total_size(sizeof(u8))) + /* _RINGS_RX_PUSH */
	64	+ nla_total_size(sizeof(u32)) + /* _RINGS_TX_PUSH_BUF_LEN */
	65	+ nla_total_size(sizeof(u32)); /* _RINGS_TX_PUSH_BUF_LEN_MAX */
61	66	}
62	67
63	68	static int rings_fill_reply(struct sk_buff *skb,
@@ -67,6 +72,7 @@ static int rings_fill_reply(struct sk_buff *skb, · 3 unmodified lines
67	72	const struct rings_reply_data *data = RINGS_REPDATA(reply_base);
68	73	const struct kernel_ethtool_ringparam *kr = &data->kernel_ringparam;
69	74	const struct ethtool_ringparam *ringparam = &data->ringparam;
	75	+ u32 supported_ring_params = data->supported_ring_params;
70	76
71	77	WARN_ON(kr->tcp_data_split > ETHTOOL_TCP_DATA_SPLIT_ENABLED);
72	78
@@ -98,7 +104,12 @@ static int rings_fill_reply(struct sk_buff *skb, · 25 unmodified lines
98	104	(kr->cqe_size &&
99	105	(nla_put_u32(skb, ETHTOOL_A_RINGS_CQE_SIZE, kr->cqe_size))) \|\|
100	106	nla_put_u8(skb, ETHTOOL_A_RINGS_TX_PUSH, !!kr->tx_push) \|\|
101		− nla_put_u8(skb, ETHTOOL_A_RINGS_RX_PUSH, !!kr->rx_push))
	107	+ nla_put_u8(skb, ETHTOOL_A_RINGS_RX_PUSH, !!kr->rx_push) \|\|
	108	+ ((supported_ring_params & ETHTOOL_RING_USE_TX_PUSH_BUF_LEN) &&
	109	+ (nla_put_u32(skb, ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX,
	110	+ kr->tx_push_buf_max_len) \|\|
	111	+ nla_put_u32(skb, ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN,
	112	+ kr->tx_push_buf_len))))
102	113	return -EMSGSIZE;
103	114
104	115	return 0;
@@ -117,6 +128,7 @@ const struct nla_policy ethnl_rings_set_policy[] = { · 12 unmodified lines
117	128	[ETHTOOL_A_RINGS_CQE_SIZE] = NLA_POLICY_MIN(NLA_U32, 1),
118	129	[ETHTOOL_A_RINGS_TX_PUSH] = NLA_POLICY_MAX(NLA_U8, 1),
119	130	[ETHTOOL_A_RINGS_RX_PUSH] = NLA_POLICY_MAX(NLA_U8, 1),
	131	+ [ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN] = { .type = NLA_U32 },
120	132	};
121	133
122	134	static int
@@ -158,6 +170,14 @@ ethnl_set_rings_validate(struct ethnl_req_info *req_info, · 35 unmodified lines
158	170	return -EOPNOTSUPP;
159	171	}
160	172
	173	+ if (tb[ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN] &&
	174	+ !(ops->supported_ring_params & ETHTOOL_RING_USE_TX_PUSH_BUF_LEN)) {
	175	+ NL_SET_ERR_MSG_ATTR(info->extack,
	176	+ tb[ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN],
	177	+ "setting tx push buf len is not supported");
	178	+ return -EOPNOTSUPP;
	179	+ }
	180	+
161	181	return ops->get_ringparam && ops->set_ringparam ? 1 : -EOPNOTSUPP;
162	182	}
163	183
@@ -189,6 +209,8 @@ ethnl_set_rings(struct ethnl_req_info req_info, struct genl_info info) · 25 unmodified lines
189	209	tb[ETHTOOL_A_RINGS_TX_PUSH], &mod);
190	210	ethnl_update_u8(&kernel_ringparam.rx_push,
191	211	tb[ETHTOOL_A_RINGS_RX_PUSH], &mod);
	212	+ ethnl_update_u32(&kernel_ringparam.tx_push_buf_len,
	213	+ tb[ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN], &mod);
192	214	if (!mod)
193	215	return 0;
194	216
@@ -209,6 +231,14 @@ ethnl_set_rings(struct ethnl_req_info req_info, struct genl_info info) · 14 unmodified lines
209	231	return -EINVAL;
210	232	}
211	233
	234	+ if (kernel_ringparam.tx_push_buf_len > kernel_ringparam.tx_push_buf_max_len) {
	235	+ NL_SET_ERR_MSG_ATTR_FMT(info->extack, tb[ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN],
	236	+ "Requested TX push buffer exceeds the maximum of %u",
	237	+ kernel_ringparam.tx_push_buf_max_len);
	238	+
	239	+ return -EINVAL;
	240	+ }
	241	+
212	242	ret = dev->ethtool_ops->set_ringparam(dev, &ringparam,
213	243	&kernel_ringparam, info->extack);
214	244	return ret < 0 ? ret : 1;

ethtool: Add support for configuring tx_push_buf_len

Keyboard shortcuts

General

Issues and pull requests

Issues, pull requests and Inbox

Repository code