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8574cf4055
linux/net/smc/smc_llc.c
Karsten Graul 8574cf4055 net/smc: allocate index for a new link 
Add smc_llc_alloc_alt_link() to find a free link index for a new link,
depending on the new link group type. And update constants for the
maximum number of links to 3 (2 symmetric and 1 dangling asymmetric link).
These maximum numbers are the same as used by other implementations of the
SMC-R protocol.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:05 -07:00

1026 lines
28 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* Shared Memory Communications over RDMA (SMC-R) and RoCE
*
* Link Layer Control (LLC)
*
* Copyright IBM Corp. 2016
*
* Author(s): Klaus Wacker <Klaus.Wacker@de.ibm.com>
* Ursula Braun <ubraun@linux.vnet.ibm.com>
*/
#include <net/tcp.h>
#include <rdma/ib_verbs.h>
#include "smc.h"
#include "smc_core.h"
#include "smc_clc.h"
#include "smc_llc.h"
#define SMC_LLC_DATA_LEN 40
struct smc_llc_hdr {
struct smc_wr_rx_hdr common;
u8 length; /* 44 */
#if defined(__BIG_ENDIAN_BITFIELD)
u8 reserved:4,
add_link_rej_rsn:4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
u8 add_link_rej_rsn:4,
reserved:4;
#endif
u8 flags;
};
#define SMC_LLC_FLAG_NO_RMBE_EYEC 0x03
struct smc_llc_msg_confirm_link { /* type 0x01 */
struct smc_llc_hdr hd;
u8 sender_mac[ETH_ALEN];
u8 sender_gid[SMC_GID_SIZE];
u8 sender_qp_num[3];
u8 link_num;
u8 link_uid[SMC_LGR_ID_SIZE];
u8 max_links;
u8 reserved[9];
};
#define SMC_LLC_FLAG_ADD_LNK_REJ 0x40
#define SMC_LLC_REJ_RSN_NO_ALT_PATH 1
#define SMC_LLC_ADD_LNK_MAX_LINKS 2
struct smc_llc_msg_add_link { /* type 0x02 */
struct smc_llc_hdr hd;
u8 sender_mac[ETH_ALEN];
u8 reserved2[2];
u8 sender_gid[SMC_GID_SIZE];
u8 sender_qp_num[3];
u8 link_num;
#if defined(__BIG_ENDIAN_BITFIELD)
u8 reserved3 : 4,
qp_mtu : 4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
u8 qp_mtu : 4,
reserved3 : 4;
#endif
u8 initial_psn[3];
u8 reserved[8];
};
#define SMC_LLC_FLAG_DEL_LINK_ALL 0x40
#define SMC_LLC_FLAG_DEL_LINK_ORDERLY 0x20
struct smc_llc_msg_del_link { /* type 0x04 */
struct smc_llc_hdr hd;
u8 link_num;
__be32 reason;
u8 reserved[35];
} __packed; /* format defined in RFC7609 */
struct smc_llc_msg_test_link { /* type 0x07 */
struct smc_llc_hdr hd;
u8 user_data[16];
u8 reserved[24];
};
struct smc_rmb_rtoken {
union {
u8 num_rkeys; /* first rtoken byte of CONFIRM LINK msg */
/* is actually the num of rtokens, first */
/* rtoken is always for the current link */
u8 link_id; /* link id of the rtoken */
};
__be32 rmb_key;
__be64 rmb_vaddr;
} __packed; /* format defined in RFC7609 */
#define SMC_LLC_RKEYS_PER_MSG 3
struct smc_llc_msg_confirm_rkey { /* type 0x06 */
struct smc_llc_hdr hd;
struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
u8 reserved;
};
#define SMC_LLC_DEL_RKEY_MAX 8
#define SMC_LLC_FLAG_RKEY_RETRY 0x10
#define SMC_LLC_FLAG_RKEY_NEG 0x20
struct smc_llc_msg_delete_rkey { /* type 0x09 */
struct smc_llc_hdr hd;
u8 num_rkeys;
u8 err_mask;
u8 reserved[2];
__be32 rkey[8];
u8 reserved2[4];
};
union smc_llc_msg {
struct smc_llc_msg_confirm_link confirm_link;
struct smc_llc_msg_add_link add_link;
struct smc_llc_msg_del_link delete_link;
struct smc_llc_msg_confirm_rkey confirm_rkey;
struct smc_llc_msg_delete_rkey delete_rkey;
struct smc_llc_msg_test_link test_link;
struct {
struct smc_llc_hdr hdr;
u8 data[SMC_LLC_DATA_LEN];
} raw;
};
#define SMC_LLC_FLAG_RESP 0x80
struct smc_llc_qentry {
struct list_head list;
struct smc_link *link;
union smc_llc_msg msg;
};
struct smc_llc_qentry *smc_llc_flow_qentry_clr(struct smc_llc_flow *flow)
{
struct smc_llc_qentry *qentry = flow->qentry;
flow->qentry = NULL;
return qentry;
}
void smc_llc_flow_qentry_del(struct smc_llc_flow *flow)
{
struct smc_llc_qentry *qentry;
if (flow->qentry) {
qentry = flow->qentry;
flow->qentry = NULL;
kfree(qentry);
}
}
static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow,
struct smc_llc_qentry *qentry)
{
flow->qentry = qentry;
}
/* try to start a new llc flow, initiated by an incoming llc msg */
static bool smc_llc_flow_start(struct smc_llc_flow *flow,
struct smc_llc_qentry *qentry)
{
struct smc_link_group *lgr = qentry->link->lgr;
spin_lock_bh(&lgr->llc_flow_lock);
if (flow->type) {
/* a flow is already active */
if ((qentry->msg.raw.hdr.common.type == SMC_LLC_ADD_LINK ||
qentry->msg.raw.hdr.common.type == SMC_LLC_DELETE_LINK) &&
!lgr->delayed_event) {
lgr->delayed_event = qentry;
} else {
/* forget this llc request */
kfree(qentry);
}
spin_unlock_bh(&lgr->llc_flow_lock);
return false;
}
switch (qentry->msg.raw.hdr.common.type) {
case SMC_LLC_ADD_LINK:
flow->type = SMC_LLC_FLOW_ADD_LINK;
break;
case SMC_LLC_DELETE_LINK:
flow->type = SMC_LLC_FLOW_DEL_LINK;
break;
case SMC_LLC_CONFIRM_RKEY:
case SMC_LLC_DELETE_RKEY:
flow->type = SMC_LLC_FLOW_RKEY;
break;
default:
flow->type = SMC_LLC_FLOW_NONE;
}
if (qentry == lgr->delayed_event)
lgr->delayed_event = NULL;
spin_unlock_bh(&lgr->llc_flow_lock);
smc_llc_flow_qentry_set(flow, qentry);
return true;
}
/* start a new local llc flow, wait till current flow finished */
int smc_llc_flow_initiate(struct smc_link_group *lgr,
enum smc_llc_flowtype type)
{
enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE;
int rc;
/* all flows except confirm_rkey and delete_rkey are exclusive,
* confirm/delete rkey flows can run concurrently (local and remote)
*/
if (type == SMC_LLC_FLOW_RKEY)
allowed_remote = SMC_LLC_FLOW_RKEY;
again:
if (list_empty(&lgr->list))
return -ENODEV;
spin_lock_bh(&lgr->llc_flow_lock);
if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
(lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
lgr->llc_flow_rmt.type == allowed_remote)) {
lgr->llc_flow_lcl.type = type;
spin_unlock_bh(&lgr->llc_flow_lock);
return 0;
}
spin_unlock_bh(&lgr->llc_flow_lock);
rc = wait_event_interruptible_timeout(lgr->llc_waiter,
(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
(lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
lgr->llc_flow_rmt.type == allowed_remote)),
SMC_LLC_WAIT_TIME);
if (!rc)
return -ETIMEDOUT;
goto again;
}
/* finish the current llc flow */
void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
{
spin_lock_bh(&lgr->llc_flow_lock);
memset(flow, 0, sizeof(*flow));
flow->type = SMC_LLC_FLOW_NONE;
spin_unlock_bh(&lgr->llc_flow_lock);
if (!list_empty(&lgr->list) && lgr->delayed_event &&
flow == &lgr->llc_flow_lcl)
schedule_work(&lgr->llc_event_work);
else
wake_up_interruptible(&lgr->llc_waiter);
}
/* lnk is optional and used for early wakeup when link goes down, useful in
* cases where we wait for a response on the link after we sent a request
*/
struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
struct smc_link *lnk,
int time_out, u8 exp_msg)
{
struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
wait_event_interruptible_timeout(lgr->llc_waiter,
(flow->qentry ||
(lnk && !smc_link_usable(lnk)) ||
list_empty(&lgr->list)),
time_out);
if (!flow->qentry ||
(lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
smc_llc_flow_qentry_del(flow);
goto out;
}
if (exp_msg && flow->qentry->msg.raw.hdr.common.type != exp_msg) {
if (exp_msg == SMC_LLC_ADD_LINK &&
flow->qentry->msg.raw.hdr.common.type ==
SMC_LLC_DELETE_LINK) {
/* flow_start will delay the unexpected msg */
smc_llc_flow_start(&lgr->llc_flow_lcl,
smc_llc_flow_qentry_clr(flow));
return NULL;
}
smc_llc_flow_qentry_del(flow);
}
out:
return flow->qentry;
}
/********************************** send *************************************/
struct smc_llc_tx_pend {
};
/* handler for send/transmission completion of an LLC msg */
static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
struct smc_link *link,
enum ib_wc_status wc_status)
{
/* future work: handle wc_status error for recovery and failover */
}
/**
* smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
* @link: Pointer to SMC link used for sending LLC control message.
* @wr_buf: Out variable returning pointer to work request payload buffer.
* @pend: Out variable returning pointer to private pending WR tracking.
* It's the context the transmit complete handler will get.
*
* Reserves and pre-fills an entry for a pending work request send/tx.
* Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
* Can sleep due to smc_get_ctrl_buf (if not in softirq context).
*
* Return: 0 on success, otherwise an error value.
*/
static int smc_llc_add_pending_send(struct smc_link *link,
struct smc_wr_buf **wr_buf,
struct smc_wr_tx_pend_priv **pend)
{
int rc;
rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, NULL,
pend);
if (rc < 0)
return rc;
BUILD_BUG_ON_MSG(
sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
"must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
BUILD_BUG_ON_MSG(
sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
"must adapt SMC_WR_TX_SIZE to sizeof(struct smc_llc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()");
BUILD_BUG_ON_MSG(
sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
"must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
return 0;
}
/* high-level API to send LLC confirm link */
int smc_llc_send_confirm_link(struct smc_link *link,
enum smc_llc_reqresp reqresp)
{
struct smc_link_group *lgr = smc_get_lgr(link);
struct smc_llc_msg_confirm_link *confllc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
int rc;
rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
if (rc)
return rc;
confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
memset(confllc, 0, sizeof(*confllc));
confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
if (reqresp == SMC_LLC_RESP)
confllc->hd.flags |= SMC_LLC_FLAG_RESP;
memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
ETH_ALEN);
memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
confllc->link_num = link->link_id;
memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS; /* enforce peer resp. */
/* send llc message */
rc = smc_wr_tx_send(link, pend);
return rc;
}
/* send LLC confirm rkey request */
static int smc_llc_send_confirm_rkey(struct smc_link *send_link,
struct smc_buf_desc *rmb_desc)
{
struct smc_llc_msg_confirm_rkey *rkeyllc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
struct smc_link *link;
int i, rc, rtok_ix;
rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend);
if (rc)
return rc;
rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
memset(rkeyllc, 0, sizeof(*rkeyllc));
rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
rtok_ix = 1;
for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
link = &send_link->lgr->lnk[i];
if (link->state == SMC_LNK_ACTIVE && link != send_link) {
rkeyllc->rtoken[rtok_ix].link_id = link->link_id;
rkeyllc->rtoken[rtok_ix].rmb_key =
htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
rkeyllc->rtoken[rtok_ix].rmb_vaddr = cpu_to_be64(
(u64)sg_dma_address(
rmb_desc->sgt[link->link_idx].sgl));
rtok_ix++;
}
}
/* rkey of send_link is in rtoken[0] */
rkeyllc->rtoken[0].num_rkeys = rtok_ix - 1;
rkeyllc->rtoken[0].rmb_key =
htonl(rmb_desc->mr_rx[send_link->link_idx]->rkey);
rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
(u64)sg_dma_address(rmb_desc->sgt[send_link->link_idx].sgl));
/* send llc message */
rc = smc_wr_tx_send(send_link, pend);
return rc;
}
/* send LLC delete rkey request */
static int smc_llc_send_delete_rkey(struct smc_link *link,
struct smc_buf_desc *rmb_desc)
{
struct smc_llc_msg_delete_rkey *rkeyllc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
int rc;
rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
if (rc)
return rc;
rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
memset(rkeyllc, 0, sizeof(*rkeyllc));
rkeyllc->hd.common.type = SMC_LLC_DELETE_RKEY;
rkeyllc->hd.length = sizeof(struct smc_llc_msg_delete_rkey);
rkeyllc->num_rkeys = 1;
rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
/* send llc message */
rc = smc_wr_tx_send(link, pend);
return rc;
}
/* send ADD LINK request or response */
int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
struct smc_link *link_new,
enum smc_llc_reqresp reqresp)
{
struct smc_llc_msg_add_link *addllc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
int rc;
rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
if (rc)
return rc;
addllc = (struct smc_llc_msg_add_link *)wr_buf;
memset(addllc, 0, sizeof(*addllc));
addllc->hd.common.type = SMC_LLC_ADD_LINK;
addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
if (reqresp == SMC_LLC_RESP)
addllc->hd.flags |= SMC_LLC_FLAG_RESP;
memcpy(addllc->sender_mac, mac, ETH_ALEN);
memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
if (link_new) {
addllc->link_num = link_new->link_id;
hton24(addllc->sender_qp_num, link_new->roce_qp->qp_num);
hton24(addllc->initial_psn, link_new->psn_initial);
if (reqresp == SMC_LLC_REQ)
addllc->qp_mtu = link_new->path_mtu;
else
addllc->qp_mtu = min(link_new->path_mtu,
link_new->peer_mtu);
}
/* send llc message */
rc = smc_wr_tx_send(link, pend);
return rc;
}
/* send DELETE LINK request or response */
int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id,
enum smc_llc_reqresp reqresp, bool orderly,
u32 reason)
{
struct smc_llc_msg_del_link *delllc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
int rc;
rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
if (rc)
return rc;
delllc = (struct smc_llc_msg_del_link *)wr_buf;
memset(delllc, 0, sizeof(*delllc));
delllc->hd.common.type = SMC_LLC_DELETE_LINK;
delllc->hd.length = sizeof(struct smc_llc_msg_del_link);
if (reqresp == SMC_LLC_RESP)
delllc->hd.flags |= SMC_LLC_FLAG_RESP;
if (orderly)
delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
if (link_del_id)
delllc->link_num = link_del_id;
else
delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
delllc->reason = htonl(reason);
/* send llc message */
rc = smc_wr_tx_send(link, pend);
return rc;
}
/* send LLC test link request */
static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
{
struct smc_llc_msg_test_link *testllc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
int rc;
rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
if (rc)
return rc;
testllc = (struct smc_llc_msg_test_link *)wr_buf;
memset(testllc, 0, sizeof(*testllc));
testllc->hd.common.type = SMC_LLC_TEST_LINK;
testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
/* send llc message */
rc = smc_wr_tx_send(link, pend);
return rc;
}
/* schedule an llc send on link, may wait for buffers */
static int smc_llc_send_message(struct smc_link *link, void *llcbuf)
{
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
int rc;
if (!smc_link_usable(link))
return -ENOLINK;
rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
if (rc)
return rc;
memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
return smc_wr_tx_send(link, pend);
}
/********************************* receive ***********************************/
static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
enum smc_lgr_type lgr_new_t)
{
int i;
if (lgr->type == SMC_LGR_SYMMETRIC ||
(lgr->type != SMC_LGR_SINGLE &&
(lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)))
return -EMLINK;
if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
lgr_new_t == SMC_LGR_ASYMMETRIC_PEER) {
for (i = SMC_LINKS_PER_LGR_MAX - 1; i >= 0; i--)
if (lgr->lnk[i].state == SMC_LNK_UNUSED)
return i;
} else {
for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
if (lgr->lnk[i].state == SMC_LNK_UNUSED)
return i;
}
return -EMLINK;
}
static void smc_llc_rx_delete_link(struct smc_link *link,
struct smc_llc_msg_del_link *llc)
{
struct smc_link_group *lgr = smc_get_lgr(link);
smc_lgr_forget(lgr);
if (lgr->role == SMC_SERV) {
/* client asks to delete this link, send request */
smc_llc_send_delete_link(link, 0, SMC_LLC_REQ, true,
SMC_LLC_DEL_PROG_INIT_TERM);
} else {
/* server requests to delete this link, send response */
smc_llc_send_delete_link(link, 0, SMC_LLC_RESP, true,
SMC_LLC_DEL_PROG_INIT_TERM);
}
smcr_link_down_cond(link);
}
/* process a confirm_rkey request from peer, remote flow */
static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
{
struct smc_llc_msg_confirm_rkey *llc;
struct smc_llc_qentry *qentry;
struct smc_link *link;
int num_entries;
int rk_idx;
int i;
qentry = lgr->llc_flow_rmt.qentry;
llc = &qentry->msg.confirm_rkey;
link = qentry->link;
num_entries = llc->rtoken[0].num_rkeys;
/* first rkey entry is for receiving link */
rk_idx = smc_rtoken_add(link,
llc->rtoken[0].rmb_vaddr,
llc->rtoken[0].rmb_key);
if (rk_idx < 0)
goto out_err;
for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
llc->rtoken[i].rmb_vaddr,
llc->rtoken[i].rmb_key);
/* max links is 3 so there is no need to support conf_rkey_cont msgs */
goto out;
out_err:
llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
out:
llc->hd.flags |= SMC_LLC_FLAG_RESP;
smc_llc_send_message(link, &qentry->msg);
smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
}
/* process a delete_rkey request from peer, remote flow */
static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
{
struct smc_llc_msg_delete_rkey *llc;
struct smc_llc_qentry *qentry;
struct smc_link *link;
u8 err_mask = 0;
int i, max;
qentry = lgr->llc_flow_rmt.qentry;
llc = &qentry->msg.delete_rkey;
link = qentry->link;
max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
for (i = 0; i < max; i++) {
if (smc_rtoken_delete(link, llc->rkey[i]))
err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
}
if (err_mask) {
llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
llc->err_mask = err_mask;
}
llc->hd.flags |= SMC_LLC_FLAG_RESP;
smc_llc_send_message(link, &qentry->msg);
smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
}
/* flush the llc event queue */
static void smc_llc_event_flush(struct smc_link_group *lgr)
{
struct smc_llc_qentry *qentry, *q;
spin_lock_bh(&lgr->llc_event_q_lock);
list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
list_del_init(&qentry->list);
kfree(qentry);
}
spin_unlock_bh(&lgr->llc_event_q_lock);
}
static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
{
union smc_llc_msg *llc = &qentry->msg;
struct smc_link *link = qentry->link;
struct smc_link_group *lgr = link->lgr;
if (!smc_link_usable(link))
goto out;
switch (llc->raw.hdr.common.type) {
case SMC_LLC_TEST_LINK:
llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
smc_llc_send_message(link, llc);
break;
case SMC_LLC_ADD_LINK:
if (list_empty(&lgr->list))
goto out; /* lgr is terminating */
if (lgr->role == SMC_CLNT) {
if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK) {
/* a flow is waiting for this message */
smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
qentry);
wake_up_interruptible(&lgr->llc_waiter);
} else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
qentry)) {
/* tbd: schedule_work(&lgr->llc_add_link_work); */
}
} else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
/* as smc server, handle client suggestion */
/* tbd: schedule_work(&lgr->llc_add_link_work); */
}
return;
case SMC_LLC_CONFIRM_LINK:
if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
/* a flow is waiting for this message */
smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
wake_up_interruptible(&lgr->llc_waiter);
return;
}
break;
case SMC_LLC_DELETE_LINK:
smc_llc_rx_delete_link(link, &llc->delete_link);
break;
case SMC_LLC_CONFIRM_RKEY:
/* new request from remote, assign to remote flow */
if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
/* process here, does not wait for more llc msgs */
smc_llc_rmt_conf_rkey(lgr);
smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
}
return;
case SMC_LLC_CONFIRM_RKEY_CONT:
/* not used because max links is 3, and 3 rkeys fit into
* one CONFIRM_RKEY message
*/
break;
case SMC_LLC_DELETE_RKEY:
/* new request from remote, assign to remote flow */
if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
/* process here, does not wait for more llc msgs */
smc_llc_rmt_delete_rkey(lgr);
smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
}
return;
}
out:
kfree(qentry);
}
/* worker to process llc messages on the event queue */
static void smc_llc_event_work(struct work_struct *work)
{
struct smc_link_group *lgr = container_of(work, struct smc_link_group,
llc_event_work);
struct smc_llc_qentry *qentry;
if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
if (smc_link_usable(lgr->delayed_event->link)) {
smc_llc_event_handler(lgr->delayed_event);
} else {
qentry = lgr->delayed_event;
lgr->delayed_event = NULL;
kfree(qentry);
}
}
again:
spin_lock_bh(&lgr->llc_event_q_lock);
if (!list_empty(&lgr->llc_event_q)) {
qentry = list_first_entry(&lgr->llc_event_q,
struct smc_llc_qentry, list);
list_del_init(&qentry->list);
spin_unlock_bh(&lgr->llc_event_q_lock);
smc_llc_event_handler(qentry);
goto again;
}
spin_unlock_bh(&lgr->llc_event_q_lock);
}
/* process llc responses in tasklet context */
static void smc_llc_rx_response(struct smc_link *link,
struct smc_llc_qentry *qentry)
{
u8 llc_type = qentry->msg.raw.hdr.common.type;
switch (llc_type) {
case SMC_LLC_TEST_LINK:
if (link->state == SMC_LNK_ACTIVE)
complete(&link->llc_testlink_resp);
break;
case SMC_LLC_ADD_LINK:
case SMC_LLC_CONFIRM_LINK:
case SMC_LLC_CONFIRM_RKEY:
case SMC_LLC_DELETE_RKEY:
/* assign responses to the local flow, we requested them */
smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
wake_up_interruptible(&link->lgr->llc_waiter);
return;
case SMC_LLC_DELETE_LINK:
if (link->lgr->role == SMC_SERV)
smc_lgr_schedule_free_work_fast(link->lgr);
break;
case SMC_LLC_CONFIRM_RKEY_CONT:
/* not used because max links is 3 */
break;
}
kfree(qentry);
}
static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
{
struct smc_link_group *lgr = link->lgr;
struct smc_llc_qentry *qentry;
unsigned long flags;
qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
if (!qentry)
return;
qentry->link = link;
INIT_LIST_HEAD(&qentry->list);
memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
/* process responses immediately */
if (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) {
smc_llc_rx_response(link, qentry);
return;
}
/* add requests to event queue */
spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
list_add_tail(&qentry->list, &lgr->llc_event_q);
spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
schedule_work(&link->lgr->llc_event_work);
}
/* copy received msg and add it to the event queue */
static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
{
struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
union smc_llc_msg *llc = buf;
if (wc->byte_len < sizeof(*llc))
return; /* short message */
if (llc->raw.hdr.length != sizeof(*llc))
return; /* invalid message */
smc_llc_enqueue(link, llc);
}
/***************************** worker, utils *********************************/
static void smc_llc_testlink_work(struct work_struct *work)
{
struct smc_link *link = container_of(to_delayed_work(work),
struct smc_link, llc_testlink_wrk);
unsigned long next_interval;
unsigned long expire_time;
u8 user_data[16] = { 0 };
int rc;
if (link->state != SMC_LNK_ACTIVE)
return; /* don't reschedule worker */
expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
if (time_is_after_jiffies(expire_time)) {
next_interval = expire_time - jiffies;
goto out;
}
reinit_completion(&link->llc_testlink_resp);
smc_llc_send_test_link(link, user_data);
/* receive TEST LINK response over RoCE fabric */
rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
SMC_LLC_WAIT_TIME);
if (link->state != SMC_LNK_ACTIVE)
return; /* link state changed */
if (rc <= 0) {
smcr_link_down_cond_sched(link);
return;
}
next_interval = link->llc_testlink_time;
out:
schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
}
void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
{
struct net *net = sock_net(smc->clcsock->sk);
INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
INIT_LIST_HEAD(&lgr->llc_event_q);
spin_lock_init(&lgr->llc_event_q_lock);
spin_lock_init(&lgr->llc_flow_lock);
init_waitqueue_head(&lgr->llc_waiter);
mutex_init(&lgr->llc_conf_mutex);
lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time;
}
/* called after lgr was removed from lgr_list */
void smc_llc_lgr_clear(struct smc_link_group *lgr)
{
smc_llc_event_flush(lgr);
wake_up_interruptible_all(&lgr->llc_waiter);
cancel_work_sync(&lgr->llc_event_work);
if (lgr->delayed_event) {
kfree(lgr->delayed_event);
lgr->delayed_event = NULL;
}
}
int smc_llc_link_init(struct smc_link *link)
{
init_completion(&link->llc_testlink_resp);
INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
return 0;
}
void smc_llc_link_active(struct smc_link *link)
{
link->state = SMC_LNK_ACTIVE;
if (link->lgr->llc_testlink_time) {
link->llc_testlink_time = link->lgr->llc_testlink_time * HZ;
schedule_delayed_work(&link->llc_testlink_wrk,
link->llc_testlink_time);
}
}
/* called in worker context */
void smc_llc_link_clear(struct smc_link *link)
{
complete(&link->llc_testlink_resp);
cancel_delayed_work_sync(&link->llc_testlink_wrk);
smc_wr_wakeup_reg_wait(link);
smc_wr_wakeup_tx_wait(link);
}
/* register a new rtoken at the remote peer (for all links) */
int smc_llc_do_confirm_rkey(struct smc_link *send_link,
struct smc_buf_desc *rmb_desc)
{
struct smc_link_group *lgr = send_link->lgr;
struct smc_llc_qentry *qentry = NULL;
int rc = 0;
rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
if (rc)
goto out;
/* receive CONFIRM RKEY response from server over RoCE fabric */
qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
SMC_LLC_CONFIRM_RKEY);
if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
rc = -EFAULT;
out:
if (qentry)
smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
return rc;
}
/* unregister an rtoken at the remote peer */
int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
struct smc_buf_desc *rmb_desc)
{
struct smc_llc_qentry *qentry = NULL;
struct smc_link *send_link;
int rc = 0;
send_link = smc_llc_usable_link(lgr);
if (!send_link)
return -ENOLINK;
/* protected by llc_flow control */
rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
if (rc)
goto out;
/* receive DELETE RKEY response from server over RoCE fabric */
qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
SMC_LLC_DELETE_RKEY);
if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
rc = -EFAULT;
out:
if (qentry)
smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
return rc;
}
/* evaluate confirm link request or response */
int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
enum smc_llc_reqresp type)
{
if (type == SMC_LLC_REQ) /* SMC server assigns link_id */
qentry->link->link_id = qentry->msg.confirm_link.link_num;
if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
return -ENOTSUPP;
return 0;
}
/***************************** init, exit, misc ******************************/
static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_CONFIRM_LINK
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_TEST_LINK
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_ADD_LINK
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_DELETE_LINK
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_CONFIRM_RKEY
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_CONFIRM_RKEY_CONT
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_DELETE_RKEY
},
{
.handler = NULL,
}
};
int __init smc_llc_init(void)
{
struct smc_wr_rx_handler *handler;
int rc = 0;
for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
INIT_HLIST_NODE(&handler->list);
rc = smc_wr_rx_register_handler(handler);
if (rc)
break;
}
return rc;
}
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