net/smc: implement DMB-related operations of loopback-ism

This implements DMB (un)registration and data move operations of
loopback-ism device.

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>

diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
index 0349632a76c42929de70c80c5ec61e2cbb569a0d..d75852549b00732fd06cc8a30983b20666eed9e6 100644 (file)
--- a/net/smc/smc_loopback.c
+++ b/net/smc/smc_loopback.c
@@ -15,10 +15,12 @@
 #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_DMA_ADDR_INVALID   (~(dma_addr_t)0)
 
 static const char smc_lo_dev_name[] = "loopback-ism";
 static struct smc_lo_dev *lo_dev;
@@ -48,6 +50,125 @@ static int smc_lo_query_rgid(struct smcd_dev *smcd, struct smcd_gid *rgid,
        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;
+
+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);
+
+       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 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;
+
+       /* remove dmb from hash table */
+       write_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) {
+               write_unlock_bh(&ldev->dmb_ht_lock);
+               return -EINVAL;
+       }
+       hash_del(&dmb_node->list);
+       write_unlock_bh(&ldev->dmb_ht_lock);
+
+       clear_bit(dmb_node->sba_idx, ldev->sba_idx_mask);
+       kfree(dmb_node->cpu_addr);
+       kfree(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;
+
+       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);
+
+       if (sf) {
+               conn = smcd->conn[rmb_node->sba_idx];
+               if (conn && !conn->killed)
+                       tasklet_schedule(&conn->rx_tsklet);
+               else
+                       return -EPIPE;
+       }
+       return 0;
+}
+
 static int smc_lo_supports_v2(void)
 {
        return SMC_LO_V2_CAPABLE;
@@ -74,14 +195,14 @@ static struct device *smc_lo_get_dev(struct smcd_dev *smcd)
 
 static const struct smcd_ops lo_ops = {
        .query_remote_gid = smc_lo_query_rgid,
-       .register_dmb           = NULL,
-       .unregister_dmb         = NULL,
+       .register_dmb = smc_lo_register_dmb,
+       .unregister_dmb = smc_lo_unregister_dmb,
        .add_vlan_id            = NULL,
        .del_vlan_id            = NULL,
        .set_vlan_required      = NULL,
        .reset_vlan_required    = NULL,
        .signal_event           = NULL,
-       .move_data              = 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,
@@ -146,6 +267,8 @@ static void smcd_lo_unregister_dev(struct smc_lo_dev *ldev)
 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);
        return smcd_lo_register_dev(ldev);
 }
 

diff --git a/net/smc/smc_loopback.h b/net/smc/smc_loopback.h
index d7df79f7bb646aa2017e45545527c97bdc455bd2..b8206338309f3669b376d448a68edf2cad318bf1 100644 (file)
--- a/net/smc/smc_loopback.h
+++ b/net/smc/smc_loopback.h
@@ -20,13 +20,26 @@
 
 #if IS_ENABLED(CONFIG_SMC_LO)
 #define SMC_LO_MAX_DMBS                5000
+#define SMC_LO_DMBS_HASH_BITS  12
 #define SMC_LO_RESERVED_CHID   0xFFFF
 
+struct smc_lo_dmb_node {
+       struct hlist_node list;
+       u64 token;
+       u32 len;
+       u32 sba_idx;
+       void *cpu_addr;
+       dma_addr_t dma_addr;
+};
+
 struct smc_lo_dev {
        struct smcd_dev *smcd;
        struct device dev;
        u16 chid;
        struct smcd_gid local_gid;
+       rwlock_t dmb_ht_lock;
+       DECLARE_BITMAP(sba_idx_mask, SMC_LO_MAX_DMBS);
+       DECLARE_HASHTABLE(dmb_ht, SMC_LO_DMBS_HASH_BITS);
 };
 
 int smc_loopback_init(void);