[PATCH net-next 03/14] net/smc: separate find device functions

Karsten Graul
2020-09-26T10:44:54Z

This patch provides better separation of device determinations
in function smc_listen_work(). No functional change.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
net/smc/af_smc.c | 111 ++++++++++++++++++++++++++++------------------
net/smc/smc_clc.c | 6 +--
net/smc/smc_clc.h | 13 +++++-
3 files changed, 84 insertions(+), 46 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 1a02d3665c46..911482741224 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1188,7 +1188,6 @@ static int smc_listen_rdma_init(struct smc_sock *new_smc,

/* listen worker: initialize connection and buffers for SMC-D */
static int smc_listen_ism_init(struct smc_sock *new_smc,
- struct smc_clc_msg_proposal *pclc,
struct smc_init_info *ini)
{
int rc;
@@ -1211,6 +1210,26 @@ static int smc_listen_ism_init(struct smc_sock *new_smc,
return 0;
}

+static void smc_find_ism_device_serv(struct smc_sock *new_smc,
+ struct smc_clc_msg_proposal *pclc,
+ struct smc_init_info *ini)
+{
+ struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
+
+ if (!smcd_indicated(pclc->hdr.typev1))
+ goto not_found;
+ ini->is_smcd = true; /* prepare ISM check */
+ ini->ism_peer_gid = pclc_smcd->gid;
+ if (smc_find_ism_device(new_smc, ini))
+ goto not_found;
+ if (!smc_listen_ism_init(new_smc, ini))
+ return; /* ISM device found */
+
+not_found:
+ ini->ism_dev = NULL;
+ ini->is_smcd = false;
+}
+
/* listen worker: register buffers */
static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
{
@@ -1225,6 +1244,47 @@ static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
return 0;
}

+static int smc_find_rdma_device_serv(struct smc_sock *new_smc,
+ struct smc_clc_msg_proposal *pclc,
+ struct smc_init_info *ini)
+{
+ int rc;
+
+ if (!smcr_indicated(pclc->hdr.typev1))
+ return SMC_CLC_DECL_NOSMCDEV;
+
+ /* prepare RDMA check */
+ ini->ib_lcl = &pclc->lcl;
+ rc = smc_find_rdma_device(new_smc, ini);
+ if (rc) {
+ /* no RDMA device found */
+ if (pclc->hdr.typev1 == SMC_TYPE_B)
+ /* neither ISM nor RDMA device found */
+ rc = SMC_CLC_DECL_NOSMCDEV;
+ return rc;
+ }
+ rc = smc_listen_rdma_init(new_smc, ini);
+ if (rc)
+ return rc;
+ return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
+}
+
+/* determine the local device matching to proposal */
+static int smc_listen_find_device(struct smc_sock *new_smc,
+ struct smc_clc_msg_proposal *pclc,
+ struct smc_init_info *ini)
+{
+ /* check if ISM is available */
+ smc_find_ism_device_serv(new_smc, pclc, ini);
+ if (ini->is_smcd)
+ return 0;
+ if (pclc->hdr.typev1 == SMC_TYPE_D)
+ return SMC_CLC_DECL_NOSMCDDEV; /* skip RDMA and decline */
+
+ /* check if RDMA is available */
+ return smc_find_rdma_device_serv(new_smc, pclc, ini);
+}
+
/* listen worker: finish RDMA setup */
static int smc_listen_rdma_finish(struct smc_sock *new_smc,
struct smc_clc_msg_accept_confirm *cclc,
@@ -1250,7 +1310,7 @@ static int smc_listen_rdma_finish(struct smc_sock *new_smc,
return reason_code;
}

-/* setup for RDMA connection of server */
+/* setup for connection of server */
static void smc_listen_work(struct work_struct *work)
{
struct smc_sock *new_smc = container_of(work, struct smc_sock,
@@ -1260,7 +1320,6 @@ static void smc_listen_work(struct work_struct *work)
struct smc_clc_msg_proposal_area *buf;
struct smc_clc_msg_proposal *pclc;
struct smc_init_info ini = {0};
- bool ism_supported = false;
int rc = 0;

if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
@@ -1315,42 +1374,10 @@ static void smc_listen_work(struct work_struct *work)
smc_rx_init(new_smc);
smc_tx_init(new_smc);

- /* check if ISM is available */
- if (pclc->hdr.typev1 == SMC_TYPE_D || pclc->hdr.typev1 == SMC_TYPE_B) {
- struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
-
- ini.is_smcd = true; /* prepare ISM check */
- ini.ism_peer_gid = pclc_smcd->gid;
- rc = smc_find_ism_device(new_smc, &ini);
- if (!rc)
- rc = smc_listen_ism_init(new_smc, pclc, &ini);
- if (!rc)
- ism_supported = true;
- else if (pclc->hdr.typev1 == SMC_TYPE_D)
- goto out_unlock; /* skip RDMA and decline */
- }
-
- /* check if RDMA is available */
- if (!ism_supported) { /* SMC_TYPE_R or SMC_TYPE_B */
- /* prepare RDMA check */
- ini.is_smcd = false;
- ini.ism_dev = NULL;
- ini.ib_lcl = &pclc->lcl;
- rc = smc_find_rdma_device(new_smc, &ini);
- if (rc) {
- /* no RDMA device found */
- if (pclc->hdr.typev1 == SMC_TYPE_B)
- /* neither ISM nor RDMA device found */
- rc = SMC_CLC_DECL_NOSMCDEV;
- goto out_unlock;
- }
- rc = smc_listen_rdma_init(new_smc, &ini);
- if (rc)
- goto out_unlock;
- rc = smc_listen_rdma_reg(new_smc, ini.first_contact_local);
- if (rc)
- goto out_unlock;
- }
+ /* determine ISM or RoCE device used for connection */
+ rc = smc_listen_find_device(new_smc, pclc, &ini);
+ if (rc)
+ goto out_unlock;

/* send SMC Accept CLC message */
rc = smc_clc_send_accept(new_smc, ini.first_contact_local);
@@ -1358,20 +1385,20 @@ static void smc_listen_work(struct work_struct *work)
goto out_unlock;

/* SMC-D does not need this lock any more */
- if (ism_supported)
+ if (ini.is_smcd)
mutex_unlock(&smc_server_lgr_pending);

/* receive SMC Confirm CLC message */
rc = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
SMC_CLC_CONFIRM, CLC_WAIT_TIME);
if (rc) {
- if (!ism_supported)
+ if (!ini.is_smcd)
goto out_unlock;
goto out_decl;
}

/* finish worker */
- if (!ism_supported) {
+ if (!ini.is_smcd) {
rc = smc_listen_rdma_finish(new_smc, &cclc,
ini.first_contact_local);
if (rc)
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 524d2b225640..85b41c125368 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -450,7 +450,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
pclc_base->hdr.type = SMC_CLC_PROPOSAL;
pclc_base->hdr.version = SMC_V1; /* SMC version */
pclc_base->hdr.typev1 = smc_type;
- if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
+ if (smcr_indicated(smc_type)) {
/* add SMC-R specifics */
memcpy(pclc_base->lcl.id_for_peer, local_systemid,
sizeof(local_systemid));
@@ -459,7 +459,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
ETH_ALEN);
pclc_base->iparea_offset = htons(0);
}
- if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
+ if (smcd_indicated(smc_type)) {
/* add SMC-D specifics */
plen += sizeof(*pclc_smcd);
pclc_base->iparea_offset = htons(sizeof(*pclc_smcd));
@@ -472,7 +472,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
i = 0;
vec[i].iov_base = pclc_base;
vec[i++].iov_len = sizeof(*pclc_base);
- if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
+ if (smcd_indicated(smc_type)) {
vec[i].iov_base = pclc_smcd;
vec[i++].iov_len = sizeof(*pclc_smcd);
}
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 5b2d0582886e..5f9fda15f7ff 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -180,11 +180,22 @@ smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
}

+static inline bool smcr_indicated(int smc_type)
+{
+ return smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B;
+}
+
+static inline bool smcd_indicated(int smc_type)
+{
+ return smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B;
+}
+
/* get SMC-D info from proposal message */
static inline struct smc_clc_msg_smcd *
smc_get_clc_msg_smcd(struct smc_clc_msg_proposal *prop)
{
- if (ntohs(prop->iparea_offset) != sizeof(struct smc_clc_msg_smcd))
+ if (smcd_indicated(prop->hdr.type) &&
+ ntohs(prop->iparea_offset) != sizeof(struct smc_clc_msg_smcd))
return NULL;

return (struct smc_clc_msg_smcd *)(prop + 1);
--
2.17.1