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OpenCloudOS-Kernel/net/smc/smc_core.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Shared Memory Communications over RDMA (SMC-R) and RoCE
*
* Basic Transport Functions exploiting Infiniband API
*
* Copyright IBM Corp. 2016
*
* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
*/
#include <linux/socket.h>
#include <linux/if_vlan.h>
#include <linux/random.h>
#include <linux/workqueue.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_cache.h>
#include "smc.h"
#include "smc_clc.h"
#include "smc_core.h"
#include "smc_ib.h"
#include "smc_wr.h"
#include "smc_llc.h"
#include "smc_cdc.h"
#include "smc_close.h"
#include "smc_ism.h"
#define SMC_LGR_NUM_INCR 256
#define SMC_LGR_FREE_DELAY_SERV (600 * HZ)
#define SMC_LGR_FREE_DELAY_CLNT (SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
#define SMC_LGR_FREE_DELAY_FAST (8 * HZ)
static struct smc_lgr_list smc_lgr_list = { /* established link groups */
.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
.list = LIST_HEAD_INIT(smc_lgr_list.list),
.num = 0,
};
static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
struct smc_buf_desc *buf_desc);
static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
{
/* client link group creation always follows the server link group
* creation. For client use a somewhat higher removal delay time,
* otherwise there is a risk of out-of-sync link groups.
*/
mod_delayed_work(system_wq, &lgr->free_work,
(!lgr->is_smcd && lgr->role == SMC_CLNT) ?
SMC_LGR_FREE_DELAY_CLNT : SMC_LGR_FREE_DELAY_SERV);
}
void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr)
{
mod_delayed_work(system_wq, &lgr->free_work, SMC_LGR_FREE_DELAY_FAST);
}
/* Register connection's alert token in our lookup structure.
* To use rbtrees we have to implement our own insert core.
* Requires @conns_lock
* @smc connection to register
* Returns 0 on success, != otherwise.
*/
static void smc_lgr_add_alert_token(struct smc_connection *conn)
{
struct rb_node **link, *parent = NULL;
u32 token = conn->alert_token_local;
link = &conn->lgr->conns_all.rb_node;
while (*link) {
struct smc_connection *cur = rb_entry(*link,
struct smc_connection, alert_node);
parent = *link;
if (cur->alert_token_local > token)
link = &parent->rb_left;
else
link = &parent->rb_right;
}
/* Put the new node there */
rb_link_node(&conn->alert_node, parent, link);
rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
}
/* Register connection in link group by assigning an alert token
* registered in a search tree.
* Requires @conns_lock
* Note that '0' is a reserved value and not assigned.
*/
static void smc_lgr_register_conn(struct smc_connection *conn)
{
struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
static atomic_t nexttoken = ATOMIC_INIT(0);
/* find a new alert_token_local value not yet used by some connection
* in this link group
*/
sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
while (!conn->alert_token_local) {
conn->alert_token_local = atomic_inc_return(&nexttoken);
if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
conn->alert_token_local = 0;
}
smc_lgr_add_alert_token(conn);
conn->lgr->conns_num++;
}
/* Unregister connection and reset the alert token of the given connection<
*/
static void __smc_lgr_unregister_conn(struct smc_connection *conn)
{
struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
struct smc_link_group *lgr = conn->lgr;
rb_erase(&conn->alert_node, &lgr->conns_all);
lgr->conns_num--;
conn->alert_token_local = 0;
sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
}
/* Unregister connection from lgr
*/
static void smc_lgr_unregister_conn(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
if (!lgr)
return;
write_lock_bh(&lgr->conns_lock);
if (conn->alert_token_local) {
__smc_lgr_unregister_conn(conn);
}
write_unlock_bh(&lgr->conns_lock);
}
/* Send delete link, either as client to request the initiation
* of the DELETE LINK sequence from server; or as server to
* initiate the delete processing. See smc_llc_rx_delete_link().
*/
static int smc_link_send_delete(struct smc_link *lnk)
{
if (lnk->state == SMC_LNK_ACTIVE &&
!smc_llc_send_delete_link(lnk, SMC_LLC_REQ, true)) {
smc_llc_link_deleting(lnk);
return 0;
}
return -ENOTCONN;
}
static void smc_lgr_free(struct smc_link_group *lgr);
static void smc_lgr_free_work(struct work_struct *work)
{
struct smc_link_group *lgr = container_of(to_delayed_work(work),
struct smc_link_group,
free_work);
bool conns;
spin_lock_bh(&smc_lgr_list.lock);
read_lock_bh(&lgr->conns_lock);
conns = RB_EMPTY_ROOT(&lgr->conns_all);
read_unlock_bh(&lgr->conns_lock);
if (!conns) { /* number of lgr connections is no longer zero */
spin_unlock_bh(&smc_lgr_list.lock);
return;
}
if (!list_empty(&lgr->list))
list_del_init(&lgr->list); /* remove from smc_lgr_list */
spin_unlock_bh(&smc_lgr_list.lock);
if (!lgr->is_smcd && !lgr->terminating) {
struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
/* try to send del link msg, on error free lgr immediately */
if (lnk->state == SMC_LNK_ACTIVE &&
!smc_link_send_delete(lnk)) {
/* reschedule in case we never receive a response */
smc_lgr_schedule_free_work(lgr);
return;
}
}
if (!delayed_work_pending(&lgr->free_work)) {
struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)
smc_llc_link_inactive(lnk);
if (lgr->is_smcd)
smc_ism_signal_shutdown(lgr);
smc_lgr_free(lgr);
}
}
/* create a new SMC link group */
static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
{
struct smc_link_group *lgr;
struct smc_link *lnk;
u8 rndvec[3];
int rc = 0;
int i;
if (ini->is_smcd && ini->vlan_id) {
if (smc_ism_get_vlan(ini->ism_dev, ini->vlan_id)) {
rc = SMC_CLC_DECL_ISMVLANERR;
goto out;
}
}
lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
if (!lgr) {
rc = SMC_CLC_DECL_MEM;
goto out;
}
lgr->is_smcd = ini->is_smcd;
lgr->sync_err = 0;
lgr->vlan_id = ini->vlan_id;
rwlock_init(&lgr->sndbufs_lock);
rwlock_init(&lgr->rmbs_lock);
rwlock_init(&lgr->conns_lock);
for (i = 0; i < SMC_RMBE_SIZES; i++) {
INIT_LIST_HEAD(&lgr->sndbufs[i]);
INIT_LIST_HEAD(&lgr->rmbs[i]);
}
smc_lgr_list.num += SMC_LGR_NUM_INCR;
memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
lgr->conns_all = RB_ROOT;
if (ini->is_smcd) {
/* SMC-D specific settings */
lgr->peer_gid = ini->ism_gid;
lgr->smcd = ini->ism_dev;
} else {
/* SMC-R specific settings */
lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer,
SMC_SYSTEMID_LEN);
lnk = &lgr->lnk[SMC_SINGLE_LINK];
/* initialize link */
lnk->state = SMC_LNK_ACTIVATING;
lnk->link_id = SMC_SINGLE_LINK;
lnk->smcibdev = ini->ib_dev;
lnk->ibport = ini->ib_port;
lnk->path_mtu =
ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
if (!ini->ib_dev->initialized)
smc_ib_setup_per_ibdev(ini->ib_dev);
get_random_bytes(rndvec, sizeof(rndvec));
lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
(rndvec[2] << 16);
rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
ini->vlan_id, lnk->gid,
&lnk->sgid_index);
if (rc)
goto free_lgr;
rc = smc_llc_link_init(lnk);
if (rc)
goto free_lgr;
rc = smc_wr_alloc_link_mem(lnk);
if (rc)
goto clear_llc_lnk;
rc = smc_ib_create_protection_domain(lnk);
if (rc)
goto free_link_mem;
rc = smc_ib_create_queue_pair(lnk);
if (rc)
goto dealloc_pd;
rc = smc_wr_create_link(lnk);
if (rc)
goto destroy_qp;
}
smc->conn.lgr = lgr;
spin_lock_bh(&smc_lgr_list.lock);
list_add(&lgr->list, &smc_lgr_list.list);
spin_unlock_bh(&smc_lgr_list.lock);
return 0;
destroy_qp:
smc_ib_destroy_queue_pair(lnk);
dealloc_pd:
smc_ib_dealloc_protection_domain(lnk);
free_link_mem:
smc_wr_free_link_mem(lnk);
clear_llc_lnk:
smc_llc_link_clear(lnk);
free_lgr:
kfree(lgr);
out:
if (rc < 0) {
if (rc == -ENOMEM)
rc = SMC_CLC_DECL_MEM;
else
rc = SMC_CLC_DECL_INTERR;
}
return rc;
}
static void smc_buf_unuse(struct smc_connection *conn,
struct smc_link_group *lgr)
{
if (conn->sndbuf_desc)
conn->sndbuf_desc->used = 0;
if (conn->rmb_desc) {
if (!conn->rmb_desc->regerr) {
if (!lgr->is_smcd) {
/* unregister rmb with peer */
smc_llc_do_delete_rkey(
&lgr->lnk[SMC_SINGLE_LINK],
conn->rmb_desc);
}
conn->rmb_desc->used = 0;
} else {
/* buf registration failed, reuse not possible */
write_lock_bh(&lgr->rmbs_lock);
list_del(&conn->rmb_desc->list);
write_unlock_bh(&lgr->rmbs_lock);
smc_buf_free(lgr, true, conn->rmb_desc);
}
}
}
/* remove a finished connection from its link group */
void smc_conn_free(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
if (!lgr)
return;
if (lgr->is_smcd) {
smc_ism_unset_conn(conn);
tasklet_kill(&conn->rx_tsklet);
} else {
smc_cdc_tx_dismiss_slots(conn);
}
smc_lgr_unregister_conn(conn);
smc_buf_unuse(conn, lgr); /* allow buffer reuse */
conn->lgr = NULL;
if (!lgr->conns_num)
smc_lgr_schedule_free_work(lgr);
}
static void smc_link_clear(struct smc_link *lnk)
{
lnk->peer_qpn = 0;
smc_llc_link_clear(lnk);
smc_ib_modify_qp_reset(lnk);
smc_wr_free_link(lnk);
smc_ib_destroy_queue_pair(lnk);
smc_ib_dealloc_protection_domain(lnk);
smc_wr_free_link_mem(lnk);
}
static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
struct smc_buf_desc *buf_desc)
{
struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
if (is_rmb) {
if (buf_desc->mr_rx[SMC_SINGLE_LINK])
smc_ib_put_memory_region(
buf_desc->mr_rx[SMC_SINGLE_LINK]);
smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
DMA_FROM_DEVICE);
} else {
smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
DMA_TO_DEVICE);
}
sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
if (buf_desc->pages)
__free_pages(buf_desc->pages, buf_desc->order);
kfree(buf_desc);
}
static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
struct smc_buf_desc *buf_desc)
{
if (is_dmb) {
/* restore original buf len */
buf_desc->len += sizeof(struct smcd_cdc_msg);
smc_ism_unregister_dmb(lgr->smcd, buf_desc);
} else {
kfree(buf_desc->cpu_addr);
}
kfree(buf_desc);
}
static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
struct smc_buf_desc *buf_desc)
{
if (lgr->is_smcd)
smcd_buf_free(lgr, is_rmb, buf_desc);
else
smcr_buf_free(lgr, is_rmb, buf_desc);
}
static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
{
struct smc_buf_desc *buf_desc, *bf_desc;
struct list_head *buf_list;
int i;
for (i = 0; i < SMC_RMBE_SIZES; i++) {
if (is_rmb)
buf_list = &lgr->rmbs[i];
else
buf_list = &lgr->sndbufs[i];
list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
list) {
list_del(&buf_desc->list);
smc_buf_free(lgr, is_rmb, buf_desc);
}
}
}
static void smc_lgr_free_bufs(struct smc_link_group *lgr)
{
/* free send buffers */
__smc_lgr_free_bufs(lgr, false);
/* free rmbs */
__smc_lgr_free_bufs(lgr, true);
}
/* remove a link group */
static void smc_lgr_free(struct smc_link_group *lgr)
{
smc_lgr_free_bufs(lgr);
if (lgr->is_smcd)
smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
else
smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
kfree(lgr);
}
void smc_lgr_forget(struct smc_link_group *lgr)
{
spin_lock_bh(&smc_lgr_list.lock);
/* do not use this link group for new connections */
if (!list_empty(&lgr->list))
list_del_init(&lgr->list);
spin_unlock_bh(&smc_lgr_list.lock);
}
/* terminate linkgroup abnormally */
static void __smc_lgr_terminate(struct smc_link_group *lgr)
{
struct smc_connection *conn;
struct smc_sock *smc;
struct rb_node *node;
if (lgr->terminating)
return; /* lgr already terminating */
lgr->terminating = 1;
if (!list_empty(&lgr->list)) /* forget lgr */
list_del_init(&lgr->list);
if (!lgr->is_smcd)
smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
write_lock_bh(&lgr->conns_lock);
node = rb_first(&lgr->conns_all);
while (node) {
conn = rb_entry(node, struct smc_connection, alert_node);
smc = container_of(conn, struct smc_sock, conn);
sock_hold(&smc->sk); /* sock_put in close work */
conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
__smc_lgr_unregister_conn(conn);
conn->lgr = NULL;
write_unlock_bh(&lgr->conns_lock);
if (!schedule_work(&conn->close_work))
sock_put(&smc->sk);
write_lock_bh(&lgr->conns_lock);
node = rb_first(&lgr->conns_all);
}
write_unlock_bh(&lgr->conns_lock);
if (!lgr->is_smcd)
wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
smc_lgr_schedule_free_work(lgr);
}
void smc_lgr_terminate(struct smc_link_group *lgr)
{
spin_lock_bh(&smc_lgr_list.lock);
__smc_lgr_terminate(lgr);
spin_unlock_bh(&smc_lgr_list.lock);
}
/* Called when IB port is terminated */
void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
{
struct smc_link_group *lgr, *l;
spin_lock_bh(&smc_lgr_list.lock);
list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
if (!lgr->is_smcd &&
lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
__smc_lgr_terminate(lgr);
}
spin_unlock_bh(&smc_lgr_list.lock);
}
/* Called when SMC-D device is terminated or peer is lost */
void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
{
struct smc_link_group *lgr, *l;
LIST_HEAD(lgr_free_list);
/* run common cleanup function and build free list */
spin_lock_bh(&smc_lgr_list.lock);
list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
if (lgr->is_smcd && lgr->smcd == dev &&
(!peer_gid || lgr->peer_gid == peer_gid) &&
(vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
__smc_lgr_terminate(lgr);
list_move(&lgr->list, &lgr_free_list);
}
}
spin_unlock_bh(&smc_lgr_list.lock);
/* cancel the regular free workers and actually free lgrs */
list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
list_del_init(&lgr->list);
cancel_delayed_work_sync(&lgr->free_work);
if (!peer_gid && vlan == VLAN_VID_MASK) /* dev terminated? */
smc_ism_signal_shutdown(lgr);
smc_lgr_free(lgr);
}
}
/* Determine vlan of internal TCP socket.
* @vlan_id: address to store the determined vlan id into
*/
int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
{
struct dst_entry *dst = sk_dst_get(clcsock->sk);
struct net_device *ndev;
int i, nest_lvl, rc = 0;
ini->vlan_id = 0;
if (!dst) {
rc = -ENOTCONN;
goto out;
}
if (!dst->dev) {
rc = -ENODEV;
goto out_rel;
}
ndev = dst->dev;
if (is_vlan_dev(ndev)) {
ini->vlan_id = vlan_dev_vlan_id(ndev);
goto out_rel;
}
rtnl_lock();
nest_lvl = dev_get_nest_level(ndev);
for (i = 0; i < nest_lvl; i++) {
struct list_head *lower = &ndev->adj_list.lower;
if (list_empty(lower))
break;
lower = lower->next;
ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
if (is_vlan_dev(ndev)) {
ini->vlan_id = vlan_dev_vlan_id(ndev);
break;
}
}
rtnl_unlock();
out_rel:
dst_release(dst);
out:
return rc;
}
static bool smcr_lgr_match(struct smc_link_group *lgr,
struct smc_clc_msg_local *lcl,
enum smc_lgr_role role, u32 clcqpn)
{
return !memcmp(lgr->peer_systemid, lcl->id_for_peer,
SMC_SYSTEMID_LEN) &&
!memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
SMC_GID_SIZE) &&
!memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
sizeof(lcl->mac)) &&
lgr->role == role &&
(lgr->role == SMC_SERV ||
lgr->lnk[SMC_SINGLE_LINK].peer_qpn == clcqpn);
}
static bool smcd_lgr_match(struct smc_link_group *lgr,
struct smcd_dev *smcismdev, u64 peer_gid)
{
return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
}
/* create a new SMC connection (and a new link group if necessary) */
int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
{
struct smc_connection *conn = &smc->conn;
struct smc_link_group *lgr;
enum smc_lgr_role role;
int rc = 0;
ini->cln_first_contact = SMC_FIRST_CONTACT;
role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
if (role == SMC_CLNT && ini->srv_first_contact)
/* create new link group as well */
goto create;
/* determine if an existing link group can be reused */
spin_lock_bh(&smc_lgr_list.lock);
list_for_each_entry(lgr, &smc_lgr_list.list, list) {
write_lock_bh(&lgr->conns_lock);
if ((ini->is_smcd ?
smcd_lgr_match(lgr, ini->ism_dev, ini->ism_gid) :
smcr_lgr_match(lgr, ini->ib_lcl, role, ini->ib_clcqpn)) &&
!lgr->sync_err &&
lgr->vlan_id == ini->vlan_id &&
(role == SMC_CLNT ||
lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
/* link group found */
ini->cln_first_contact = SMC_REUSE_CONTACT;
conn->lgr = lgr;
smc_lgr_register_conn(conn); /* add smc conn to lgr */
if (delayed_work_pending(&lgr->free_work))
cancel_delayed_work(&lgr->free_work);
write_unlock_bh(&lgr->conns_lock);
break;
}
write_unlock_bh(&lgr->conns_lock);
}
spin_unlock_bh(&smc_lgr_list.lock);
if (role == SMC_CLNT && !ini->srv_first_contact &&
ini->cln_first_contact == SMC_FIRST_CONTACT) {
/* Server reuses a link group, but Client wants to start
* a new one
* send out_of_sync decline, reason synchr. error
*/
return SMC_CLC_DECL_SYNCERR;
}
create:
if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
rc = smc_lgr_create(smc, ini);
if (rc)
goto out;
lgr = conn->lgr;
write_lock_bh(&lgr->conns_lock);
smc_lgr_register_conn(conn); /* add smc conn to lgr */
write_unlock_bh(&lgr->conns_lock);
}
conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
conn->urg_state = SMC_URG_READ;
if (ini->is_smcd) {
conn->rx_off = sizeof(struct smcd_cdc_msg);
smcd_cdc_rx_init(conn); /* init tasklet for this conn */
}
#ifndef KERNEL_HAS_ATOMIC64
spin_lock_init(&conn->acurs_lock);
#endif
out:
return rc;
}
/* convert the RMB size into the compressed notation - minimum 16K.
* In contrast to plain ilog2, this rounds towards the next power of 2,
* so the socket application gets at least its desired sndbuf / rcvbuf size.
*/
static u8 smc_compress_bufsize(int size)
{
u8 compressed;
if (size <= SMC_BUF_MIN_SIZE)
return 0;
size = (size - 1) >> 14;
compressed = ilog2(size) + 1;
if (compressed >= SMC_RMBE_SIZES)
compressed = SMC_RMBE_SIZES - 1;
return compressed;
}
/* convert the RMB size from compressed notation into integer */
int smc_uncompress_bufsize(u8 compressed)
{
u32 size;
size = 0x00000001 << (((int)compressed) + 14);
return (int)size;
}
/* try to reuse a sndbuf or rmb description slot for a certain
* buffer size; if not available, return NULL
*/
static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
rwlock_t *lock,
struct list_head *buf_list)
{
struct smc_buf_desc *buf_slot;
read_lock_bh(lock);
list_for_each_entry(buf_slot, buf_list, list) {
if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
read_unlock_bh(lock);
return buf_slot;
}
}
read_unlock_bh(lock);
return NULL;
}
/* one of the conditions for announcing a receiver's current window size is
* that it "results in a minimum increase in the window size of 10% of the
* receive buffer space" [RFC7609]
*/
static inline int smc_rmb_wnd_update_limit(int rmbe_size)
{
return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
}
static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
bool is_rmb, int bufsize)
{
struct smc_buf_desc *buf_desc;
struct smc_link *lnk;
int rc;
/* try to alloc a new buffer */
buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
if (!buf_desc)
return ERR_PTR(-ENOMEM);
buf_desc->order = get_order(bufsize);
buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
__GFP_NOMEMALLOC | __GFP_COMP |
__GFP_NORETRY | __GFP_ZERO,
buf_desc->order);
if (!buf_desc->pages) {
kfree(buf_desc);
return ERR_PTR(-EAGAIN);
}
buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
/* build the sg table from the pages */
lnk = &lgr->lnk[SMC_SINGLE_LINK];
rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
GFP_KERNEL);
if (rc) {
smc_buf_free(lgr, is_rmb, buf_desc);
return ERR_PTR(rc);
}
sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
buf_desc->cpu_addr, bufsize);
/* map sg table to DMA address */
rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
/* SMC protocol depends on mapping to one DMA address only */
if (rc != 1) {
smc_buf_free(lgr, is_rmb, buf_desc);
return ERR_PTR(-EAGAIN);
}
/* create a new memory region for the RMB */
if (is_rmb) {
rc = smc_ib_get_memory_region(lnk->roce_pd,
IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_LOCAL_WRITE,
buf_desc);
if (rc) {
smc_buf_free(lgr, is_rmb, buf_desc);
return ERR_PTR(rc);
}
}
buf_desc->len = bufsize;
return buf_desc;
}
#define SMCD_DMBE_SIZES 7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
bool is_dmb, int bufsize)
{
struct smc_buf_desc *buf_desc;
int rc;
if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
return ERR_PTR(-EAGAIN);
/* try to alloc a new DMB */
buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
if (!buf_desc)
return ERR_PTR(-ENOMEM);
if (is_dmb) {
rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
if (rc) {
kfree(buf_desc);
return ERR_PTR(-EAGAIN);
}
buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
/* CDC header stored in buf. So, pretend it was smaller */
buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
} else {
buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
__GFP_NOWARN | __GFP_NORETRY |
__GFP_NOMEMALLOC);
if (!buf_desc->cpu_addr) {
kfree(buf_desc);
return ERR_PTR(-EAGAIN);
}
buf_desc->len = bufsize;
}
return buf_desc;
}
static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
{
struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
struct smc_connection *conn = &smc->conn;
struct smc_link_group *lgr = conn->lgr;
struct list_head *buf_list;
int bufsize, bufsize_short;
int sk_buf_size;
rwlock_t *lock;
if (is_rmb)
/* use socket recv buffer size (w/o overhead) as start value */
sk_buf_size = smc->sk.sk_rcvbuf / 2;
else
/* use socket send buffer size (w/o overhead) as start value */
sk_buf_size = smc->sk.sk_sndbuf / 2;
for (bufsize_short = smc_compress_bufsize(sk_buf_size);
bufsize_short >= 0; bufsize_short--) {
if (is_rmb) {
lock = &lgr->rmbs_lock;
buf_list = &lgr->rmbs[bufsize_short];
} else {
lock = &lgr->sndbufs_lock;
buf_list = &lgr->sndbufs[bufsize_short];
}
bufsize = smc_uncompress_bufsize(bufsize_short);
if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
continue;
/* check for reusable slot in the link group */
buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
if (buf_desc) {
memset(buf_desc->cpu_addr, 0, bufsize);
break; /* found reusable slot */
}
if (is_smcd)
buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
else
buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
if (PTR_ERR(buf_desc) == -ENOMEM)
break;
if (IS_ERR(buf_desc))
continue;
buf_desc->used = 1;
write_lock_bh(lock);
list_add(&buf_desc->list, buf_list);
write_unlock_bh(lock);
break; /* found */
}
if (IS_ERR(buf_desc))
return -ENOMEM;
if (is_rmb) {
conn->rmb_desc = buf_desc;
conn->rmbe_size_short = bufsize_short;
smc->sk.sk_rcvbuf = bufsize * 2;
atomic_set(&conn->bytes_to_rcv, 0);
conn->rmbe_update_limit =
smc_rmb_wnd_update_limit(buf_desc->len);
if (is_smcd)
smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
} else {
conn->sndbuf_desc = buf_desc;
smc->sk.sk_sndbuf = bufsize * 2;
atomic_set(&conn->sndbuf_space, bufsize);
}
return 0;
}
void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
if (!conn->lgr || conn->lgr->is_smcd)
return;
smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
conn->sndbuf_desc, DMA_TO_DEVICE);
}
void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
if (!conn->lgr || conn->lgr->is_smcd)
return;
smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
conn->sndbuf_desc, DMA_TO_DEVICE);
}
void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
if (!conn->lgr || conn->lgr->is_smcd)
return;
smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
conn->rmb_desc, DMA_FROM_DEVICE);
}
void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
if (!conn->lgr || conn->lgr->is_smcd)
return;
smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
conn->rmb_desc, DMA_FROM_DEVICE);
}
/* create the send and receive buffer for an SMC socket;
* receive buffers are called RMBs;
* (even though the SMC protocol allows more than one RMB-element per RMB,
* the Linux implementation uses just one RMB-element per RMB, i.e. uses an
* extra RMB for every connection in a link group
*/
int smc_buf_create(struct smc_sock *smc, bool is_smcd)
{
int rc;
/* create send buffer */
rc = __smc_buf_create(smc, is_smcd, false);
if (rc)
return rc;
/* create rmb */
rc = __smc_buf_create(smc, is_smcd, true);
if (rc)
smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
return rc;
}
static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
{
int i;
for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
if (!test_and_set_bit(i, lgr->rtokens_used_mask))
return i;
}
return -ENOSPC;
}
/* add a new rtoken from peer */
int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
{
u64 dma_addr = be64_to_cpu(nw_vaddr);
u32 rkey = ntohl(nw_rkey);
int i;
for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
(lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
test_bit(i, lgr->rtokens_used_mask)) {
/* already in list */
return i;
}
}
i = smc_rmb_reserve_rtoken_idx(lgr);
if (i < 0)
return i;
lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
return i;
}
/* delete an rtoken */
int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
{
u32 rkey = ntohl(nw_rkey);
int i;
for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
test_bit(i, lgr->rtokens_used_mask)) {
lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
clear_bit(i, lgr->rtokens_used_mask);
return 0;
}
}
return -ENOENT;
}
/* save rkey and dma_addr received from peer during clc handshake */
int smc_rmb_rtoken_handling(struct smc_connection *conn,
struct smc_clc_msg_accept_confirm *clc)
{
conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
clc->rmb_rkey);
if (conn->rtoken_idx < 0)
return conn->rtoken_idx;
return 0;
}
/* Called (from smc_exit) when module is removed */
void smc_core_exit(void)
{
struct smc_link_group *lgr, *lg;
LIST_HEAD(lgr_freeing_list);
spin_lock_bh(&smc_lgr_list.lock);
if (!list_empty(&smc_lgr_list.list))
list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
spin_unlock_bh(&smc_lgr_list.lock);
list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
list_del_init(&lgr->list);
if (!lgr->is_smcd) {
struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
if (lnk->state == SMC_LNK_ACTIVE)
smc_llc_send_delete_link(lnk, SMC_LLC_REQ,
false);
smc_llc_link_inactive(lnk);
}
cancel_delayed_work_sync(&lgr->free_work);
if (lgr->is_smcd)
smc_ism_signal_shutdown(lgr);
smc_lgr_free(lgr); /* free link group */
}
}
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