linux/net/smc/smc_loopback.c
Wen Gu c3a910f238 net/smc: implement DMB-merged operations of loopback-ism
This implements operations related to merging sndbuf with peer DMB in
loopback-ism. The DMB won't be freed until no sndbuf is attached to it.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-30 13:24:49 +02:00

428 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Shared Memory Communications Direct over loopback-ism device.
*
* Functions for loopback-ism device.
*
* Copyright (c) 2024, Alibaba Inc.
*
* Author: Wen Gu <guwen@linux.alibaba.com>
* Tony Lu <tonylu@linux.alibaba.com>
*
*/
#include <linux/device.h>
#include <linux/types.h>
#include <net/smc.h>
#include "smc_cdc.h"
#include "smc_ism.h"
#include "smc_loopback.h"
#define SMC_LO_V2_CAPABLE 0x1 /* loopback-ism acts as ISMv2 */
#define SMC_LO_SUPPORT_NOCOPY 0x1
#define SMC_DMA_ADDR_INVALID (~(dma_addr_t)0)
static const char smc_lo_dev_name[] = "loopback-ism";
static struct smc_lo_dev *lo_dev;
static void smc_lo_generate_ids(struct smc_lo_dev *ldev)
{
struct smcd_gid *lgid = &ldev->local_gid;
uuid_t uuid;
uuid_gen(&uuid);
memcpy(&lgid->gid, &uuid, sizeof(lgid->gid));
memcpy(&lgid->gid_ext, (u8 *)&uuid + sizeof(lgid->gid),
sizeof(lgid->gid_ext));
ldev->chid = SMC_LO_RESERVED_CHID;
}
static int smc_lo_query_rgid(struct smcd_dev *smcd, struct smcd_gid *rgid,
u32 vid_valid, u32 vid)
{
struct smc_lo_dev *ldev = smcd->priv;
/* rgid should be the same as lgid */
if (!ldev || rgid->gid != ldev->local_gid.gid ||
rgid->gid_ext != ldev->local_gid.gid_ext)
return -ENETUNREACH;
return 0;
}
static int smc_lo_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb,
void *client_priv)
{
struct smc_lo_dmb_node *dmb_node, *tmp_node;
struct smc_lo_dev *ldev = smcd->priv;
int sba_idx, rc;
/* check space for new dmb */
for_each_clear_bit(sba_idx, ldev->sba_idx_mask, SMC_LO_MAX_DMBS) {
if (!test_and_set_bit(sba_idx, ldev->sba_idx_mask))
break;
}
if (sba_idx == SMC_LO_MAX_DMBS)
return -ENOSPC;
dmb_node = kzalloc(sizeof(*dmb_node), GFP_KERNEL);
if (!dmb_node) {
rc = -ENOMEM;
goto err_bit;
}
dmb_node->sba_idx = sba_idx;
dmb_node->len = dmb->dmb_len;
dmb_node->cpu_addr = kzalloc(dmb_node->len, GFP_KERNEL |
__GFP_NOWARN | __GFP_NORETRY |
__GFP_NOMEMALLOC);
if (!dmb_node->cpu_addr) {
rc = -ENOMEM;
goto err_node;
}
dmb_node->dma_addr = SMC_DMA_ADDR_INVALID;
refcount_set(&dmb_node->refcnt, 1);
again:
/* add new dmb into hash table */
get_random_bytes(&dmb_node->token, sizeof(dmb_node->token));
write_lock_bh(&ldev->dmb_ht_lock);
hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_node->token) {
if (tmp_node->token == dmb_node->token) {
write_unlock_bh(&ldev->dmb_ht_lock);
goto again;
}
}
hash_add(ldev->dmb_ht, &dmb_node->list, dmb_node->token);
write_unlock_bh(&ldev->dmb_ht_lock);
atomic_inc(&ldev->dmb_cnt);
dmb->sba_idx = dmb_node->sba_idx;
dmb->dmb_tok = dmb_node->token;
dmb->cpu_addr = dmb_node->cpu_addr;
dmb->dma_addr = dmb_node->dma_addr;
dmb->dmb_len = dmb_node->len;
return 0;
err_node:
kfree(dmb_node);
err_bit:
clear_bit(sba_idx, ldev->sba_idx_mask);
return rc;
}
static void __smc_lo_unregister_dmb(struct smc_lo_dev *ldev,
struct smc_lo_dmb_node *dmb_node)
{
/* remove dmb from hash table */
write_lock_bh(&ldev->dmb_ht_lock);
hash_del(&dmb_node->list);
write_unlock_bh(&ldev->dmb_ht_lock);
clear_bit(dmb_node->sba_idx, ldev->sba_idx_mask);
kvfree(dmb_node->cpu_addr);
kfree(dmb_node);
if (atomic_dec_and_test(&ldev->dmb_cnt))
wake_up(&ldev->ldev_release);
}
static int smc_lo_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
{
struct smc_lo_dmb_node *dmb_node = NULL, *tmp_node;
struct smc_lo_dev *ldev = smcd->priv;
/* find dmb from hash table */
read_lock_bh(&ldev->dmb_ht_lock);
hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb->dmb_tok) {
if (tmp_node->token == dmb->dmb_tok) {
dmb_node = tmp_node;
break;
}
}
if (!dmb_node) {
read_unlock_bh(&ldev->dmb_ht_lock);
return -EINVAL;
}
read_unlock_bh(&ldev->dmb_ht_lock);
if (refcount_dec_and_test(&dmb_node->refcnt))
__smc_lo_unregister_dmb(ldev, dmb_node);
return 0;
}
static int smc_lo_support_dmb_nocopy(struct smcd_dev *smcd)
{
return SMC_LO_SUPPORT_NOCOPY;
}
static int smc_lo_attach_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
{
struct smc_lo_dmb_node *dmb_node = NULL, *tmp_node;
struct smc_lo_dev *ldev = smcd->priv;
/* find dmb_node according to dmb->dmb_tok */
read_lock_bh(&ldev->dmb_ht_lock);
hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb->dmb_tok) {
if (tmp_node->token == dmb->dmb_tok) {
dmb_node = tmp_node;
break;
}
}
if (!dmb_node) {
read_unlock_bh(&ldev->dmb_ht_lock);
return -EINVAL;
}
read_unlock_bh(&ldev->dmb_ht_lock);
if (!refcount_inc_not_zero(&dmb_node->refcnt))
/* the dmb is being unregistered, but has
* not been removed from the hash table.
*/
return -EINVAL;
/* provide dmb information */
dmb->sba_idx = dmb_node->sba_idx;
dmb->dmb_tok = dmb_node->token;
dmb->cpu_addr = dmb_node->cpu_addr;
dmb->dma_addr = dmb_node->dma_addr;
dmb->dmb_len = dmb_node->len;
return 0;
}
static int smc_lo_detach_dmb(struct smcd_dev *smcd, u64 token)
{
struct smc_lo_dmb_node *dmb_node = NULL, *tmp_node;
struct smc_lo_dev *ldev = smcd->priv;
/* find dmb_node according to dmb->dmb_tok */
read_lock_bh(&ldev->dmb_ht_lock);
hash_for_each_possible(ldev->dmb_ht, tmp_node, list, token) {
if (tmp_node->token == token) {
dmb_node = tmp_node;
break;
}
}
if (!dmb_node) {
read_unlock_bh(&ldev->dmb_ht_lock);
return -EINVAL;
}
read_unlock_bh(&ldev->dmb_ht_lock);
if (refcount_dec_and_test(&dmb_node->refcnt))
__smc_lo_unregister_dmb(ldev, dmb_node);
return 0;
}
static int smc_lo_move_data(struct smcd_dev *smcd, u64 dmb_tok,
unsigned int idx, bool sf, unsigned int offset,
void *data, unsigned int size)
{
struct smc_lo_dmb_node *rmb_node = NULL, *tmp_node;
struct smc_lo_dev *ldev = smcd->priv;
struct smc_connection *conn;
if (!sf)
/* since sndbuf is merged with peer DMB, there is
* no need to copy data from sndbuf to peer DMB.
*/
return 0;
read_lock_bh(&ldev->dmb_ht_lock);
hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_tok) {
if (tmp_node->token == dmb_tok) {
rmb_node = tmp_node;
break;
}
}
if (!rmb_node) {
read_unlock_bh(&ldev->dmb_ht_lock);
return -EINVAL;
}
memcpy((char *)rmb_node->cpu_addr + offset, data, size);
read_unlock_bh(&ldev->dmb_ht_lock);
conn = smcd->conn[rmb_node->sba_idx];
if (!conn || conn->killed)
return -EPIPE;
tasklet_schedule(&conn->rx_tsklet);
return 0;
}
static int smc_lo_supports_v2(void)
{
return SMC_LO_V2_CAPABLE;
}
static void smc_lo_get_local_gid(struct smcd_dev *smcd,
struct smcd_gid *smcd_gid)
{
struct smc_lo_dev *ldev = smcd->priv;
smcd_gid->gid = ldev->local_gid.gid;
smcd_gid->gid_ext = ldev->local_gid.gid_ext;
}
static u16 smc_lo_get_chid(struct smcd_dev *smcd)
{
return ((struct smc_lo_dev *)smcd->priv)->chid;
}
static struct device *smc_lo_get_dev(struct smcd_dev *smcd)
{
return &((struct smc_lo_dev *)smcd->priv)->dev;
}
static const struct smcd_ops lo_ops = {
.query_remote_gid = smc_lo_query_rgid,
.register_dmb = smc_lo_register_dmb,
.unregister_dmb = smc_lo_unregister_dmb,
.support_dmb_nocopy = smc_lo_support_dmb_nocopy,
.attach_dmb = smc_lo_attach_dmb,
.detach_dmb = smc_lo_detach_dmb,
.add_vlan_id = NULL,
.del_vlan_id = NULL,
.set_vlan_required = NULL,
.reset_vlan_required = NULL,
.signal_event = NULL,
.move_data = smc_lo_move_data,
.supports_v2 = smc_lo_supports_v2,
.get_local_gid = smc_lo_get_local_gid,
.get_chid = smc_lo_get_chid,
.get_dev = smc_lo_get_dev,
};
static struct smcd_dev *smcd_lo_alloc_dev(const struct smcd_ops *ops,
int max_dmbs)
{
struct smcd_dev *smcd;
smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
if (!smcd)
return NULL;
smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
GFP_KERNEL);
if (!smcd->conn)
goto out_smcd;
smcd->ops = ops;
spin_lock_init(&smcd->lock);
spin_lock_init(&smcd->lgr_lock);
INIT_LIST_HEAD(&smcd->vlan);
INIT_LIST_HEAD(&smcd->lgr_list);
init_waitqueue_head(&smcd->lgrs_deleted);
return smcd;
out_smcd:
kfree(smcd);
return NULL;
}
static int smcd_lo_register_dev(struct smc_lo_dev *ldev)
{
struct smcd_dev *smcd;
smcd = smcd_lo_alloc_dev(&lo_ops, SMC_LO_MAX_DMBS);
if (!smcd)
return -ENOMEM;
ldev->smcd = smcd;
smcd->priv = ldev;
smc_ism_set_v2_capable();
mutex_lock(&smcd_dev_list.mutex);
list_add(&smcd->list, &smcd_dev_list.list);
mutex_unlock(&smcd_dev_list.mutex);
pr_warn_ratelimited("smc: adding smcd device %s\n",
dev_name(&ldev->dev));
return 0;
}
static void smcd_lo_unregister_dev(struct smc_lo_dev *ldev)
{
struct smcd_dev *smcd = ldev->smcd;
pr_warn_ratelimited("smc: removing smcd device %s\n",
dev_name(&ldev->dev));
smcd->going_away = 1;
smc_smcd_terminate_all(smcd);
mutex_lock(&smcd_dev_list.mutex);
list_del_init(&smcd->list);
mutex_unlock(&smcd_dev_list.mutex);
kfree(smcd->conn);
kfree(smcd);
}
static int smc_lo_dev_init(struct smc_lo_dev *ldev)
{
smc_lo_generate_ids(ldev);
rwlock_init(&ldev->dmb_ht_lock);
hash_init(ldev->dmb_ht);
atomic_set(&ldev->dmb_cnt, 0);
init_waitqueue_head(&ldev->ldev_release);
return smcd_lo_register_dev(ldev);
}
static void smc_lo_dev_exit(struct smc_lo_dev *ldev)
{
smcd_lo_unregister_dev(ldev);
if (atomic_read(&ldev->dmb_cnt))
wait_event(ldev->ldev_release, !atomic_read(&ldev->dmb_cnt));
}
static void smc_lo_dev_release(struct device *dev)
{
struct smc_lo_dev *ldev =
container_of(dev, struct smc_lo_dev, dev);
kfree(ldev);
}
static int smc_lo_dev_probe(void)
{
struct smc_lo_dev *ldev;
int ret;
ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
if (!ldev)
return -ENOMEM;
ldev->dev.parent = NULL;
ldev->dev.release = smc_lo_dev_release;
device_initialize(&ldev->dev);
dev_set_name(&ldev->dev, smc_lo_dev_name);
ret = smc_lo_dev_init(ldev);
if (ret)
goto free_dev;
lo_dev = ldev; /* global loopback device */
return 0;
free_dev:
put_device(&ldev->dev);
return ret;
}
static void smc_lo_dev_remove(void)
{
if (!lo_dev)
return;
smc_lo_dev_exit(lo_dev);
put_device(&lo_dev->dev); /* device_initialize in smc_lo_dev_probe */
}
int smc_loopback_init(void)
{
return smc_lo_dev_probe();
}
void smc_loopback_exit(void)
{
smc_lo_dev_remove();
}