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iw_cxgb4: complete the cached SRQ buffers
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If TP fetches an SRQ buffer but ends up not using it before the connection
is aborted, then it passes the index of that SRQ buffer to the host in
ABORT_REQ_RSS or ABORT_RPL CPL message.

But, if the srqidx field is zero in the received ABORT_RPL or
ABORT_REQ_RSS CPL, then we need to read the tcb.rq_start field to see if
it really did have an RQE cached. This works around a case where HW does
not include the srqidx in the ABORT_RPL/ABORT_REQ_RSS CPL.

The final value of rq_start is the one present in TCB with the
TF_RX_PDU_OUT bit cleared. So, we need to read the TCB, examine the
TF_RX_PDU_OUT (bit 49 of t_flags) in order to determine if there's a rx
PDU feedback event pending.

Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
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Raju Rangoju authored and Jason Gunthorpe committed Feb 9, 2019
1 parent e381a1c commit 11a27e2
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Showing 3 changed files with 157 additions and 8 deletions.
161 changes: 153 additions & 8 deletions drivers/infiniband/hw/cxgb4/cm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -655,7 +655,33 @@ static int send_halfclose(struct c4iw_ep *ep)
return c4iw_l2t_send(&ep->com.dev->rdev, skb, ep->l2t);
}

static int send_abort(struct c4iw_ep *ep)
void read_tcb(struct c4iw_ep *ep)
{
struct sk_buff *skb;
struct cpl_get_tcb *req;
int wrlen = roundup(sizeof(*req), 16);

skb = get_skb(NULL, sizeof(*req), GFP_KERNEL);
if (WARN_ON(!skb))
return;

set_wr_txq(skb, CPL_PRIORITY_CONTROL, ep->ctrlq_idx);
req = (struct cpl_get_tcb *) skb_put(skb, wrlen);
memset(req, 0, wrlen);
INIT_TP_WR(req, ep->hwtid);
OPCODE_TID(req) = cpu_to_be32(MK_OPCODE_TID(CPL_GET_TCB, ep->hwtid));
req->reply_ctrl = htons(REPLY_CHAN_V(0) | QUEUENO_V(ep->rss_qid));

/*
* keep a ref on the ep so the tcb is not unlocked before this
* cpl completes. The ref is released in read_tcb_rpl().
*/
c4iw_get_ep(&ep->com);
if (WARN_ON(c4iw_ofld_send(&ep->com.dev->rdev, skb)))
c4iw_put_ep(&ep->com);
}

static int send_abort_req(struct c4iw_ep *ep)
{
u32 wrlen = roundup(sizeof(struct cpl_abort_req), 16);
struct sk_buff *req_skb = skb_dequeue(&ep->com.ep_skb_list);
Expand All @@ -670,6 +696,17 @@ static int send_abort(struct c4iw_ep *ep)
return c4iw_l2t_send(&ep->com.dev->rdev, req_skb, ep->l2t);
}

static int send_abort(struct c4iw_ep *ep)
{
if (!ep->com.qp || !ep->com.qp->srq) {
send_abort_req(ep);
return 0;
}
set_bit(ABORT_REQ_IN_PROGRESS, &ep->com.flags);
read_tcb(ep);
return 0;
}

static int send_connect(struct c4iw_ep *ep)
{
struct cpl_act_open_req *req = NULL;
Expand Down Expand Up @@ -1851,14 +1888,11 @@ static int rx_data(struct c4iw_dev *dev, struct sk_buff *skb)
return 0;
}

static void complete_cached_srq_buffers(struct c4iw_ep *ep,
__be32 srqidx_status)
static void complete_cached_srq_buffers(struct c4iw_ep *ep, u32 srqidx)
{
enum chip_type adapter_type;
u32 srqidx;

adapter_type = ep->com.dev->rdev.lldi.adapter_type;
srqidx = ABORT_RSS_SRQIDX_G(be32_to_cpu(srqidx_status));

/*
* If this TCB had a srq buffer cached, then we must complete
Expand All @@ -1876,6 +1910,7 @@ static void complete_cached_srq_buffers(struct c4iw_ep *ep,

static int abort_rpl(struct c4iw_dev *dev, struct sk_buff *skb)
{
u32 srqidx;
struct c4iw_ep *ep;
struct cpl_abort_rpl_rss6 *rpl = cplhdr(skb);
int release = 0;
Expand All @@ -1887,7 +1922,10 @@ static int abort_rpl(struct c4iw_dev *dev, struct sk_buff *skb)
return 0;
}

complete_cached_srq_buffers(ep, rpl->srqidx_status);
if (ep->com.qp && ep->com.qp->srq) {
srqidx = ABORT_RSS_SRQIDX_G(be32_to_cpu(rpl->srqidx_status));
complete_cached_srq_buffers(ep, srqidx ? srqidx : ep->srqe_idx);
}

pr_debug("ep %p tid %u\n", ep, ep->hwtid);
mutex_lock(&ep->com.mutex);
Expand Down Expand Up @@ -2746,6 +2784,21 @@ static int peer_close(struct c4iw_dev *dev, struct sk_buff *skb)
return 0;
}

static void finish_peer_abort(struct c4iw_dev *dev, struct c4iw_ep *ep)
{
complete_cached_srq_buffers(ep, ep->srqe_idx);
if (ep->com.cm_id && ep->com.qp) {
struct c4iw_qp_attributes attrs;

attrs.next_state = C4IW_QP_STATE_ERROR;
c4iw_modify_qp(ep->com.qp->rhp, ep->com.qp,
C4IW_QP_ATTR_NEXT_STATE, &attrs, 1);
}
peer_abort_upcall(ep);
release_ep_resources(ep);
c4iw_put_ep(&ep->com);
}

static int peer_abort(struct c4iw_dev *dev, struct sk_buff *skb)
{
struct cpl_abort_req_rss6 *req = cplhdr(skb);
Expand All @@ -2756,6 +2809,7 @@ static int peer_abort(struct c4iw_dev *dev, struct sk_buff *skb)
int release = 0;
unsigned int tid = GET_TID(req);
u8 status;
u32 srqidx;

u32 len = roundup(sizeof(struct cpl_abort_rpl), 16);

Expand All @@ -2775,8 +2829,6 @@ static int peer_abort(struct c4iw_dev *dev, struct sk_buff *skb)
goto deref_ep;
}

complete_cached_srq_buffers(ep, req->srqidx_status);

pr_debug("ep %p tid %u state %u\n", ep, ep->hwtid,
ep->com.state);
set_bit(PEER_ABORT, &ep->com.history);
Expand Down Expand Up @@ -2825,6 +2877,23 @@ static int peer_abort(struct c4iw_dev *dev, struct sk_buff *skb)
stop_ep_timer(ep);
/*FALLTHROUGH*/
case FPDU_MODE:
if (ep->com.qp && ep->com.qp->srq) {
srqidx = ABORT_RSS_SRQIDX_G(
be32_to_cpu(req->srqidx_status));
if (srqidx) {
complete_cached_srq_buffers(ep,
req->srqidx_status);
} else {
/* Hold ep ref until finish_peer_abort() */
c4iw_get_ep(&ep->com);
__state_set(&ep->com, ABORTING);
set_bit(PEER_ABORT_IN_PROGRESS, &ep->com.flags);
read_tcb(ep);
break;

}
}

if (ep->com.cm_id && ep->com.qp) {
attrs.next_state = C4IW_QP_STATE_ERROR;
ret = c4iw_modify_qp(ep->com.qp->rhp,
Expand Down Expand Up @@ -3726,6 +3795,80 @@ static void passive_ofld_conn_reply(struct c4iw_dev *dev, struct sk_buff *skb,
return;
}

static inline u64 t4_tcb_get_field64(__be64 *tcb, u16 word)
{
u64 tlo = be64_to_cpu(tcb[((31 - word) / 2)]);
u64 thi = be64_to_cpu(tcb[((31 - word) / 2) - 1]);
u64 t;
u32 shift = 32;

t = (thi << shift) | (tlo >> shift);

return t;
}

static inline u32 t4_tcb_get_field32(__be64 *tcb, u16 word, u32 mask, u32 shift)
{
u32 v;
u64 t = be64_to_cpu(tcb[(31 - word) / 2]);

if (word & 0x1)
shift += 32;
v = (t >> shift) & mask;
return v;
}

static int read_tcb_rpl(struct c4iw_dev *dev, struct sk_buff *skb)
{
struct cpl_get_tcb_rpl *rpl = cplhdr(skb);
__be64 *tcb = (__be64 *)(rpl + 1);
unsigned int tid = GET_TID(rpl);
struct c4iw_ep *ep;
u64 t_flags_64;
u32 rx_pdu_out;

ep = get_ep_from_tid(dev, tid);
if (!ep)
return 0;
/* Examine the TF_RX_PDU_OUT (bit 49 of the t_flags) in order to
* determine if there's a rx PDU feedback event pending.
*
* If that bit is set, it means we'll need to re-read the TCB's
* rq_start value. The final value is the one present in a TCB
* with the TF_RX_PDU_OUT bit cleared.
*/

t_flags_64 = t4_tcb_get_field64(tcb, TCB_T_FLAGS_W);
rx_pdu_out = (t_flags_64 & TF_RX_PDU_OUT_V(1)) >> TF_RX_PDU_OUT_S;

c4iw_put_ep(&ep->com); /* from get_ep_from_tid() */
c4iw_put_ep(&ep->com); /* from read_tcb() */

/* If TF_RX_PDU_OUT bit is set, re-read the TCB */
if (rx_pdu_out) {
if (++ep->rx_pdu_out_cnt >= 2) {
WARN_ONCE(1, "tcb re-read() reached the guard limit, finishing the cleanup\n");
goto cleanup;
}
read_tcb(ep);
return 0;
}

ep->srqe_idx = t4_tcb_get_field32(tcb, TCB_RQ_START_W, TCB_RQ_START_W,
TCB_RQ_START_S);
cleanup:
pr_debug("ep %p tid %u %016x\n", ep, ep->hwtid, ep->srqe_idx);

if (test_bit(PEER_ABORT_IN_PROGRESS, &ep->com.flags))
finish_peer_abort(dev, ep);
else if (test_bit(ABORT_REQ_IN_PROGRESS, &ep->com.flags))
send_abort_req(ep);
else
WARN_ONCE(1, "unexpected state!");

return 0;
}

static int deferred_fw6_msg(struct c4iw_dev *dev, struct sk_buff *skb)
{
struct cpl_fw6_msg *rpl = cplhdr(skb);
Expand Down Expand Up @@ -4046,6 +4189,7 @@ static c4iw_handler_func work_handlers[NUM_CPL_CMDS + NUM_FAKE_CPLS] = {
[CPL_CLOSE_CON_RPL] = close_con_rpl,
[CPL_RDMA_TERMINATE] = terminate,
[CPL_FW4_ACK] = fw4_ack,
[CPL_GET_TCB_RPL] = read_tcb_rpl,
[CPL_FW6_MSG] = deferred_fw6_msg,
[CPL_RX_PKT] = rx_pkt,
[FAKE_CPL_PUT_EP_SAFE] = _put_ep_safe,
Expand Down Expand Up @@ -4277,6 +4421,7 @@ c4iw_handler_func c4iw_handlers[NUM_CPL_CMDS] = {
[CPL_RDMA_TERMINATE] = sched,
[CPL_FW4_ACK] = sched,
[CPL_SET_TCB_RPL] = set_tcb_rpl,
[CPL_GET_TCB_RPL] = sched,
[CPL_FW6_MSG] = fw6_msg,
[CPL_RX_PKT] = sched
};
Expand Down
3 changes: 3 additions & 0 deletions drivers/infiniband/hw/cxgb4/iw_cxgb4.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -982,6 +982,9 @@ struct c4iw_ep {
int rcv_win;
u32 snd_wscale;
struct c4iw_ep_stats stats;
u32 srqe_idx;
u32 rx_pdu_out_cnt;
struct sk_buff *peer_abort_skb;
};

static inline struct c4iw_ep *to_ep(struct iw_cm_id *cm_id)
Expand Down
1 change: 1 addition & 0 deletions drivers/infiniband/hw/cxgb4/t4.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@
#include "t4_regs.h"
#include "t4_values.h"
#include "t4_msg.h"
#include "t4_tcb.h"
#include "t4fw_ri_api.h"

#define T4_MAX_NUM_PD 65536
Expand Down

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