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-rw-r--r--net/smc/smc_loopback.c427
1 files changed, 427 insertions, 0 deletions
diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
new file mode 100644
index 0000000000..3c5f64ca41
--- /dev/null
+++ b/net/smc/smc_loopback.c
@@ -0,0 +1,427 @@
+// 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();
+}