[PATCH 6/9] srp: use the new CQ API

Christoph Hellwig
2015-11-13T13:51:43Z

This also moves recv completion handling from hardirq context into
softirq context.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/infiniband/ulp/srp/ib_srp.c | 198 ++++++++++++++----------------------
drivers/infiniband/ulp/srp/ib_srp.h | 7 +-
2 files changed, 76 insertions(+), 129 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 3027824..57237e1 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -132,8 +132,9 @@ MODULE_PARM_DESC(ch_count,

static void srp_add_one(struct ib_device *device);
static void srp_remove_one(struct ib_device *device, void *client_data);
-static void srp_recv_completion(struct ib_cq *cq, void *ch_ptr);
-static void srp_send_completion(struct ib_cq *cq, void *ch_ptr);
+static void srp_recv_done(struct ib_cq *cq, struct ib_wc *wc);
+static void srp_handle_qp_err(struct ib_cq *cq, struct ib_wc *wc,
+ const char *opname);
static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);

static struct scsi_transport_template *ib_srp_transport_template;
@@ -445,41 +446,6 @@ static struct srp_fr_pool *srp_alloc_fr_pool(struct srp_target_port *target)
dev->max_pages_per_mr);
}

-/**
- * srp_destroy_qp() - destroy an RDMA queue pair
- * @ch: SRP RDMA channel.
- *
- * Change a queue pair into the error state and wait until all receive
- * completions have been processed before destroying it. This avoids that
- * the receive completion handler can access the queue pair while it is
- * being destroyed.
- */
-static void srp_destroy_qp(struct srp_rdma_ch *ch)
-{
- static struct ib_qp_attr attr = { .qp_state = IB_QPS_ERR };
- static struct ib_recv_wr wr = { 0 };
- struct ib_recv_wr *bad_wr;
- int ret;
-
- wr.wr_id = SRP_LAST_WR_ID;
- /* Destroying a QP and reusing ch->done is only safe if not connected */
- WARN_ON_ONCE(ch->connected);
-
- ret = ib_modify_qp(ch->qp, &attr, IB_QP_STATE);
- WARN_ONCE(ret, "ib_cm_init_qp_attr() returned %d\n", ret);
- if (ret)
- goto out;
-
- init_completion(&ch->done);
- ret = ib_post_recv(ch->qp, &wr, &bad_wr);
- WARN_ONCE(ret, "ib_post_recv() returned %d\n", ret);
- if (ret == 0)
- wait_for_completion(&ch->done);
-
-out:
- ib_destroy_qp(ch->qp);
-}
-
static int srp_create_ch_ib(struct srp_rdma_ch *ch)
{
struct srp_target_port *target = ch->target;
@@ -490,34 +456,27 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch)
struct ib_fmr_pool *fmr_pool = NULL;
struct srp_fr_pool *fr_pool = NULL;
const int m = 1 + dev->use_fast_reg;
- struct ib_cq_init_attr cq_attr = {};
int ret;

init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
if (!init_attr)
return -ENOMEM;

- /* + 1 for SRP_LAST_WR_ID */
- cq_attr.cqe = target->queue_size + 1;
- cq_attr.comp_vector = ch->comp_vector;
- recv_cq = ib_create_cq(dev->dev, srp_recv_completion, NULL, ch,
- &cq_attr);
+ /* queue_size + 1 for ib_drain_qp */
+ recv_cq = ib_alloc_cq(dev->dev, ch, target->queue_size + 1, ch->comp_vector,
+ IB_POLL_SOFTIRQ);
if (IS_ERR(recv_cq)) {
ret = PTR_ERR(recv_cq);
goto err;
}

- cq_attr.cqe = m * target->queue_size;
- cq_attr.comp_vector = ch->comp_vector;
- send_cq = ib_create_cq(dev->dev, srp_send_completion, NULL, ch,
- &cq_attr);
+ send_cq = ib_alloc_cq(dev->dev, ch, m * target->queue_size, ch->comp_vector,
+ IB_POLL_DIRECT);
if (IS_ERR(send_cq)) {
ret = PTR_ERR(send_cq);
goto err_recv_cq;
}

- ib_req_notify_cq(recv_cq, IB_CQ_NEXT_COMP);
-
init_attr->event_handler = srp_qp_event;
init_attr->cap.max_send_wr = m * target->queue_size;
init_attr->cap.max_recv_wr = target->queue_size + 1;
@@ -557,11 +516,11 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch)
}

if (ch->qp)
- srp_destroy_qp(ch);
+ ib_destroy_qp(ch->qp);
if (ch->recv_cq)
- ib_destroy_cq(ch->recv_cq);
+ ib_free_cq(ch->recv_cq);
if (ch->send_cq)
- ib_destroy_cq(ch->send_cq);
+ ib_free_cq(ch->send_cq);

ch->qp = qp;
ch->recv_cq = recv_cq;
@@ -584,10 +543,10 @@ err_qp:
ib_destroy_qp(qp);

err_send_cq:
- ib_destroy_cq(send_cq);
+ ib_free_cq(send_cq);

err_recv_cq:
- ib_destroy_cq(recv_cq);
+ ib_free_cq(recv_cq);

err:
kfree(init_attr);
@@ -623,9 +582,11 @@ static void srp_free_ch_ib(struct srp_target_port *target,
if (ch->fmr_pool)
ib_destroy_fmr_pool(ch->fmr_pool);
}
- srp_destroy_qp(ch);
- ib_destroy_cq(ch->send_cq);
- ib_destroy_cq(ch->recv_cq);
+
+ ib_drain_qp(ch->qp);
+ ib_destroy_qp(ch->qp);
+ ib_free_cq(ch->send_cq);
+ ib_free_cq(ch->recv_cq);

/*
* Avoid that the SCSI error handler tries to use this channel after
@@ -1038,7 +999,13 @@ static int srp_connect_ch(struct srp_rdma_ch *ch, bool multich)
}
}

-static int srp_inv_rkey(struct srp_rdma_ch *ch, u32 rkey)
+static void srp_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ srp_handle_qp_err(cq, wc, "INV RKEY");
+}
+
+static int srp_inv_rkey(struct srp_request *req, struct srp_rdma_ch *ch,
+ u32 rkey)
{
struct ib_send_wr *bad_wr;
struct ib_send_wr wr = {
@@ -1049,8 +1016,8 @@ static int srp_inv_rkey(struct srp_rdma_ch *ch, u32 rkey)
.ex.invalidate_rkey = rkey,
};

- wr.wr_id = LOCAL_INV_WR_ID_MASK;
-
+ wr.wr_cqe = &req->reg_cqe;
+ req->reg_cqe.done = srp_inv_rkey_done;
return ib_post_send(ch->qp, &wr, &bad_wr);
}

@@ -1072,7 +1039,7 @@ static void srp_unmap_data(struct scsi_cmnd *scmnd,
struct srp_fr_desc **pfr;

for (i = req->nmdesc, pfr = req->fr_list; i > 0; i--, pfr++) {
- res = srp_inv_rkey(ch, (*pfr)->mr->rkey);
+ res = srp_inv_rkey(req, ch, (*pfr)->mr->rkey);
if (res < 0) {
shost_printk(KERN_ERR, target->scsi_host, PFX
"Queueing INV WR for rkey %#x failed (%d)\n",
@@ -1310,7 +1277,13 @@ reset_state:
return 0;
}

+static void srp_reg_mr_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ srp_handle_qp_err(cq, wc, "FAST REG");
+}
+
static int srp_map_finish_fr(struct srp_map_state *state,
+ struct srp_request *req,
struct srp_rdma_ch *ch)
{
struct srp_target_port *target = ch->target;
@@ -1348,9 +1321,11 @@ static int srp_map_finish_fr(struct srp_map_state *state,
if (unlikely(n < 0))
return n;

+ req->reg_cqe.done = srp_reg_mr_done;
+
wr.wr.next = NULL;
wr.wr.opcode = IB_WR_REG_MR;
- wr.wr.wr_id = FAST_REG_WR_ID_MASK;
+ wr.wr.wr_cqe = &req->reg_cqe;
wr.wr.num_sge = 0;
wr.wr.send_flags = 0;
wr.mr = desc->mr;
@@ -1455,7 +1430,7 @@ static int srp_map_sg_fr(struct srp_map_state *state, struct srp_rdma_ch *ch,
while (state->sg_nents) {
int i, n;

- n = srp_map_finish_fr(state, ch);
+ n = srp_map_finish_fr(state, req, ch);
if (unlikely(n < 0))
return n;

@@ -1522,7 +1497,7 @@ static int srp_map_idb(struct srp_rdma_ch *ch, struct srp_request *req,
state.sg_nents = 1;
sg_set_buf(idb_sg, req->indirect_desc, idb_len);
idb_sg->dma_address = req->indirect_dma_addr; /* hack! */
- ret = srp_map_finish_fr(&state, ch);
+ ret = srp_map_finish_fr(&state, req, ch);
if (ret < 0)
return ret;
} else if (dev->use_fmr) {
@@ -1717,7 +1692,7 @@ static struct srp_iu *__srp_get_tx_iu(struct srp_rdma_ch *ch,
s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
struct srp_iu *iu;

- srp_send_completion(ch->send_cq, ch);
+ ib_process_cq_direct(ch->send_cq);

if (list_empty(&ch->free_tx))
return NULL;
@@ -1737,6 +1712,19 @@ static struct srp_iu *__srp_get_tx_iu(struct srp_rdma_ch *ch,
return iu;
}

+static void srp_send_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct srp_iu *iu = container_of(wc->wr_cqe, struct srp_iu, cqe);
+ struct srp_rdma_ch *ch = cq->cq_context;
+
+ if (likely(wc->status != IB_WC_SUCCESS)) {
+ srp_handle_qp_err(cq, wc, "SEND");
+ return;
+ }
+
+ list_add(&iu->list, &ch->free_tx);
+}
+
static int srp_post_send(struct srp_rdma_ch *ch, struct srp_iu *iu, int len)
{
struct srp_target_port *target = ch->target;
@@ -1747,8 +1735,10 @@ static int srp_post_send(struct srp_rdma_ch *ch, struct srp_iu *iu, int len)
list.length = len;
list.lkey = target->lkey;

+ iu->cqe.done = srp_send_done;
+
wr.next = NULL;
- wr.wr_id = (uintptr_t) iu;
+ wr.wr_cqe = &iu->cqe;
wr.sg_list = &list;
wr.num_sge = 1;
wr.opcode = IB_WR_SEND;
@@ -1767,8 +1757,10 @@ static int srp_post_recv(struct srp_rdma_ch *ch, struct srp_iu *iu)
list.length = iu->size;
list.lkey = target->lkey;

+ iu->cqe.done = srp_recv_done;
+
wr.next = NULL;
- wr.wr_id = (uintptr_t) iu;
+ wr.wr_cqe = &iu->cqe;
wr.sg_list = &list;
wr.num_sge = 1;

@@ -1900,14 +1892,20 @@ static void srp_process_aer_req(struct srp_rdma_ch *ch,
"problems processing SRP_AER_REQ\n");
}

-static void srp_handle_recv(struct srp_rdma_ch *ch, struct ib_wc *wc)
+static void srp_recv_done(struct ib_cq *cq, struct ib_wc *wc)
{
+ struct srp_iu *iu = container_of(wc->wr_cqe, struct srp_iu, cqe);
+ struct srp_rdma_ch *ch = cq->cq_context;
struct srp_target_port *target = ch->target;
struct ib_device *dev = target->srp_host->srp_dev->dev;
- struct srp_iu *iu = (struct srp_iu *) (uintptr_t) wc->wr_id;
int res;
u8 opcode;

+ if (unlikely(wc->status != IB_WC_SUCCESS)) {
+ srp_handle_qp_err(cq, wc, "RECV");
+ return;
+ }
+
ib_dma_sync_single_for_cpu(dev, iu->dma, ch->max_ti_iu_len,
DMA_FROM_DEVICE);

@@ -1970,68 +1968,22 @@ static void srp_tl_err_work(struct work_struct *work)
srp_start_tl_fail_timers(target->rport);
}

-static void srp_handle_qp_err(u64 wr_id, enum ib_wc_status wc_status,
- bool send_err, struct srp_rdma_ch *ch)
+static void srp_handle_qp_err(struct ib_cq *cq, struct ib_wc *wc,
+ const char *opname)
{
+ struct srp_rdma_ch *ch = cq->cq_context;
struct srp_target_port *target = ch->target;

- if (wr_id == SRP_LAST_WR_ID) {
- complete(&ch->done);
- return;
- }
-
if (ch->connected && !target->qp_in_error) {
- if (wr_id & LOCAL_INV_WR_ID_MASK) {
- shost_printk(KERN_ERR, target->scsi_host, PFX
- "LOCAL_INV failed with status %s (%d)\n",
- ib_wc_status_msg(wc_status), wc_status);
- } else if (wr_id & FAST_REG_WR_ID_MASK) {
- shost_printk(KERN_ERR, target->scsi_host, PFX
- "FAST_REG_MR failed status %s (%d)\n",
- ib_wc_status_msg(wc_status), wc_status);
- } else {
- shost_printk(KERN_ERR, target->scsi_host,
- PFX "failed %s status %s (%d) for iu %p\n",
- send_err ? "send" : "receive",
- ib_wc_status_msg(wc_status), wc_status,
- (void *)(uintptr_t)wr_id);
- }
+ shost_printk(KERN_ERR, target->scsi_host,
+ PFX "failed %s status %s (%d) for CQE %p\n",
+ opname, ib_wc_status_msg(wc->status), wc->status,
+ wc->wr_cqe);
queue_work(system_long_wq, &target->tl_err_work);
}
target->qp_in_error = true;
}

-static void srp_recv_completion(struct ib_cq *cq, void *ch_ptr)
-{
- struct srp_rdma_ch *ch = ch_ptr;
- struct ib_wc wc;
-
- ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
- while (ib_poll_cq(cq, 1, &wc) > 0) {
- if (likely(wc.status == IB_WC_SUCCESS)) {
- srp_handle_recv(ch, &wc);
- } else {
- srp_handle_qp_err(wc.wr_id, wc.status, false, ch);
- }
- }
-}
-
-static void srp_send_completion(struct ib_cq *cq, void *ch_ptr)
-{
- struct srp_rdma_ch *ch = ch_ptr;
- struct ib_wc wc;
- struct srp_iu *iu;
-
- while (ib_poll_cq(cq, 1, &wc) > 0) {
- if (likely(wc.status == IB_WC_SUCCESS)) {
- iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
- list_add(&iu->list, &ch->free_tx);
- } else {
- srp_handle_qp_err(wc.wr_id, wc.status, true, ch);
- }
- }
-}
-
static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
{
struct srp_target_port *target = host_to_target(shost);
@@ -3576,8 +3528,6 @@ static int __init srp_init_module(void)
{
int ret;

- BUILD_BUG_ON(FIELD_SIZEOF(struct ib_wc, wr_id) < sizeof(void *));
-
if (srp_sg_tablesize) {
pr_warn("srp_sg_tablesize is deprecated, please use cmd_sg_entries\n");
if (!cmd_sg_entries)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index 87a2a91..7fec482 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -66,11 +66,6 @@ enum {
SRP_TAG_TSK_MGMT = 1U << 31,

SRP_MAX_PAGES_PER_MR = 512,
-
- LOCAL_INV_WR_ID_MASK = 1,
- FAST_REG_WR_ID_MASK = 2,
-
- SRP_LAST_WR_ID = 0xfffffffcU,
};

enum srp_target_state {
@@ -128,6 +123,7 @@ struct srp_request {
struct srp_direct_buf *indirect_desc;
dma_addr_t indirect_dma_addr;
short nmdesc;
+ struct ib_cqe reg_cqe;
};

/**
@@ -231,6 +227,7 @@ struct srp_iu {
void *buf;
size_t size;
enum dma_data_direction direction;
+ struct ib_cqe cqe;
};

/**
--
1.9.1