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net/smc: rkey processing for a new link as SMC client
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Part of the SMC client new link establishment process is the exchange of
rkeys for all used buffers.
Add new LLC message type ADD_LINK_CONTINUE which is used to exchange
rkeys of all current RMB buffers. Add functions to iterate over all
used RMB buffers of the link group, and implement the ADD_LINK_CONTINUE
processing.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Karsten Graul authored and David S. Miller committed May 3, 2020
1 parent 336ba09 commit 87f88cd
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Showing 2 changed files with 157 additions and 1 deletion.
157 changes: 156 additions & 1 deletion net/smc/smc_llc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -70,6 +70,23 @@ struct smc_llc_msg_add_link { /* type 0x02 */
u8 reserved[8];
};

struct smc_llc_msg_add_link_cont_rt {
__be32 rmb_key;
__be32 rmb_key_new;
__be64 rmb_vaddr_new;
};

#define SMC_LLC_RKEYS_PER_CONT_MSG 2

struct smc_llc_msg_add_link_cont { /* type 0x03 */
struct smc_llc_hdr hd;
u8 link_num;
u8 num_rkeys;
u8 reserved2[2];
struct smc_llc_msg_add_link_cont_rt rt[SMC_LLC_RKEYS_PER_CONT_MSG];
u8 reserved[4];
} __packed; /* format defined in RFC7609 */

#define SMC_LLC_FLAG_DEL_LINK_ALL 0x40
#define SMC_LLC_FLAG_DEL_LINK_ORDERLY 0x20

Expand Down Expand Up @@ -121,6 +138,7 @@ struct smc_llc_msg_delete_rkey { /* type 0x09 */
union smc_llc_msg {
struct smc_llc_msg_confirm_link confirm_link;
struct smc_llc_msg_add_link add_link;
struct smc_llc_msg_add_link_cont add_link_cont;
struct smc_llc_msg_del_link delete_link;

struct smc_llc_msg_confirm_rkey confirm_rkey;
Expand Down Expand Up @@ -566,6 +584,137 @@ static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
return -EMLINK;
}

/* return first buffer from any of the next buf lists */
static struct smc_buf_desc *_smc_llc_get_next_rmb(struct smc_link_group *lgr,
int *buf_lst)
{
struct smc_buf_desc *buf_pos;

while (*buf_lst < SMC_RMBE_SIZES) {
buf_pos = list_first_entry_or_null(&lgr->rmbs[*buf_lst],
struct smc_buf_desc, list);
if (buf_pos)
return buf_pos;
(*buf_lst)++;
}
return NULL;
}

/* return next rmb from buffer lists */
static struct smc_buf_desc *smc_llc_get_next_rmb(struct smc_link_group *lgr,
int *buf_lst,
struct smc_buf_desc *buf_pos)
{
struct smc_buf_desc *buf_next;

if (!buf_pos || list_is_last(&buf_pos->list, &lgr->rmbs[*buf_lst])) {
(*buf_lst)++;
return _smc_llc_get_next_rmb(lgr, buf_lst);
}
buf_next = list_next_entry(buf_pos, list);
return buf_next;
}

static struct smc_buf_desc *smc_llc_get_first_rmb(struct smc_link_group *lgr,
int *buf_lst)
{
*buf_lst = 0;
return smc_llc_get_next_rmb(lgr, buf_lst, NULL);
}

/* send one add_link_continue msg */
static int smc_llc_add_link_cont(struct smc_link *link,
struct smc_link *link_new, u8 *num_rkeys_todo,
int *buf_lst, struct smc_buf_desc **buf_pos)
{
struct smc_llc_msg_add_link_cont *addc_llc;
struct smc_link_group *lgr = link->lgr;
int prim_lnk_idx, lnk_idx, i, rc;
struct smc_wr_tx_pend_priv *pend;
struct smc_wr_buf *wr_buf;
struct smc_buf_desc *rmb;
u8 n;

rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
if (rc)
return rc;
addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf;
memset(addc_llc, 0, sizeof(*addc_llc));

prim_lnk_idx = link->link_idx;
lnk_idx = link_new->link_idx;
addc_llc->link_num = link_new->link_id;
addc_llc->num_rkeys = *num_rkeys_todo;
n = *num_rkeys_todo;
for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
if (!*buf_pos) {
addc_llc->num_rkeys = addc_llc->num_rkeys -
*num_rkeys_todo;
*num_rkeys_todo = 0;
break;
}
rmb = *buf_pos;

addc_llc->rt[i].rmb_key = htonl(rmb->mr_rx[prim_lnk_idx]->rkey);
addc_llc->rt[i].rmb_key_new = htonl(rmb->mr_rx[lnk_idx]->rkey);
addc_llc->rt[i].rmb_vaddr_new =
cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));

(*num_rkeys_todo)--;
*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
while (*buf_pos && !(*buf_pos)->used)
*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
}
addc_llc->hd.common.type = SMC_LLC_ADD_LINK_CONT;
addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
if (lgr->role == SMC_CLNT)
addc_llc->hd.flags |= SMC_LLC_FLAG_RESP;
return smc_wr_tx_send(link, pend);
}

static int smc_llc_cli_rkey_exchange(struct smc_link *link,
struct smc_link *link_new)
{
struct smc_llc_msg_add_link_cont *addc_llc;
struct smc_link_group *lgr = link->lgr;
u8 max, num_rkeys_send, num_rkeys_recv;
struct smc_llc_qentry *qentry;
struct smc_buf_desc *buf_pos;
int buf_lst;
int rc = 0;
int i;

mutex_lock(&lgr->rmbs_lock);
num_rkeys_send = lgr->conns_num;
buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
do {
qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_TIME,
SMC_LLC_ADD_LINK_CONT);
if (!qentry) {
rc = -ETIMEDOUT;
break;
}
addc_llc = &qentry->msg.add_link_cont;
num_rkeys_recv = addc_llc->num_rkeys;
max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
for (i = 0; i < max; i++) {
smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
addc_llc->rt[i].rmb_key,
addc_llc->rt[i].rmb_vaddr_new,
addc_llc->rt[i].rmb_key_new);
num_rkeys_recv--;
}
smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
rc = smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
&buf_lst, &buf_pos);
if (rc)
break;
} while (num_rkeys_send || num_rkeys_recv);

mutex_unlock(&lgr->rmbs_lock);
return rc;
}

/* prepare and send an add link reject response */
static int smc_llc_cli_add_link_reject(struct smc_llc_qentry *qentry)
{
Expand Down Expand Up @@ -631,7 +780,7 @@ int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
lnk_new->gid, lnk_new, SMC_LLC_RESP);
if (rc)
goto out_clear_lnk;
/* tbd: rc = smc_llc_cli_rkey_exchange(link, lnk_new); */
rc = smc_llc_cli_rkey_exchange(link, lnk_new);
if (rc) {
rc = 0;
goto out_clear_lnk;
Expand Down Expand Up @@ -794,6 +943,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
}
return;
case SMC_LLC_CONFIRM_LINK:
case SMC_LLC_ADD_LINK_CONT:
if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
/* a flow is waiting for this message */
smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
Expand Down Expand Up @@ -873,6 +1023,7 @@ static void smc_llc_rx_response(struct smc_link *link,
break;
case SMC_LLC_ADD_LINK:
case SMC_LLC_CONFIRM_LINK:
case SMC_LLC_ADD_LINK_CONT:
case SMC_LLC_CONFIRM_RKEY:
case SMC_LLC_DELETE_RKEY:
/* assign responses to the local flow, we requested them */
Expand Down Expand Up @@ -1092,6 +1243,10 @@ static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
.handler = smc_llc_rx_handler,
.type = SMC_LLC_ADD_LINK
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_ADD_LINK_CONT
},
{
.handler = smc_llc_rx_handler,
.type = SMC_LLC_DELETE_LINK
Expand Down
1 change: 1 addition & 0 deletions net/smc/smc_llc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,7 @@ enum smc_llc_reqresp {
enum smc_llc_msg_type {
SMC_LLC_CONFIRM_LINK = 0x01,
SMC_LLC_ADD_LINK = 0x02,
SMC_LLC_ADD_LINK_CONT = 0x03,
SMC_LLC_DELETE_LINK = 0x04,
SMC_LLC_CONFIRM_RKEY = 0x06,
SMC_LLC_TEST_LINK = 0x07,
Expand Down

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