Define .init_cmd_priv and .exit_cmd_priv callback functions in struct
scsi_host_template. Set .cmd_size such that the SCSI core allocates
per-command private data. Use scsi_cmd_priv() to access that private
data. Remove the req_ring pointer from struct srp_rdma_ch since it is
no longer necessary. Convert srp_alloc_req_data() and srp_free_req_data()
into functions that initialize one instance of the SRP-private command
data. This is a micro-optimization since this patch removes several
pointer dereferences from the hot path.
Note: due to commit e73a5e8e8003 ("scsi: core: Only return started requests
from scsi_host_find_tag()"), it is no longer necessary to protect the
completion path against duplicate responses.
Cc: Nicolas Morey-Chaisemartin <nmoreychaisemartin@xxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
drivers/infiniband/ulp/srp/ib_srp.c | 153 ++++++++++++----------------
drivers/infiniband/ulp/srp/ib_srp.h | 2 -
2 files changed, 63 insertions(+), 92 deletions(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 70107ab0179a..71405b01b85e 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -965,67 +965,52 @@ static void srp_disconnect_target(struct srp_target_port *target)
}
}
-static void srp_free_req_data(struct srp_target_port *target,
- struct srp_rdma_ch *ch)
+static int srp_exit_cmd_priv(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
+ struct srp_target_port *target = host_to_target(shost);
struct srp_device *dev = target->srp_host->srp_dev;
struct ib_device *ibdev = dev->dev;
- struct srp_request *req;
- int i;
+ struct srp_request *req = scsi_cmd_priv(cmd);
- if (!ch->req_ring)
- return;
-
- for (i = 0; i < target->req_ring_size; ++i) {
- req = &ch->req_ring[i];
- if (dev->use_fast_reg)
- kfree(req->fr_list);
- if (req->indirect_dma_addr) {
- ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
- target->indirect_size,
- DMA_TO_DEVICE);
- }
- kfree(req->indirect_desc);
+ kfree(req->fr_list);
+ if (req->indirect_dma_addr) {
+ ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
+ target->indirect_size,
+ DMA_TO_DEVICE);
}
+ kfree(req->indirect_desc);
- kfree(ch->req_ring);
- ch->req_ring = NULL;
+ return 0;
}
-static int srp_alloc_req_data(struct srp_rdma_ch *ch)
+static int srp_init_cmd_priv(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
- struct srp_target_port *target = ch->target;
+ struct srp_target_port *target = host_to_target(shost);
struct srp_device *srp_dev = target->srp_host->srp_dev;
struct ib_device *ibdev = srp_dev->dev;
- struct srp_request *req;
+ struct srp_request *req = scsi_cmd_priv(cmd);
dma_addr_t dma_addr;
- int i, ret = -ENOMEM;
+ int ret = -ENOMEM;
- ch->req_ring = kcalloc(target->req_ring_size, sizeof(*ch->req_ring),
- GFP_KERNEL);
- if (!ch->req_ring)
- goto out;
-
- for (i = 0; i < target->req_ring_size; ++i) {
- req = &ch->req_ring[i];
- if (srp_dev->use_fast_reg) {
- req->fr_list = kmalloc_array(target->mr_per_cmd,
- sizeof(void *), GFP_KERNEL);
- if (!req->fr_list)
- goto out;
- }
- req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
- if (!req->indirect_desc)
- goto out;
-
- dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
- target->indirect_size,
- DMA_TO_DEVICE);
- if (ib_dma_mapping_error(ibdev, dma_addr))
+ if (srp_dev->use_fast_reg) {
+ req->fr_list = kmalloc_array(target->mr_per_cmd, sizeof(void *),
+ GFP_KERNEL);
+ if (!req->fr_list)
goto out;
+ }
+ req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
+ if (!req->indirect_desc)
+ goto out;
- req->indirect_dma_addr = dma_addr;
+ dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
+ target->indirect_size,
+ DMA_TO_DEVICE);
+ if (ib_dma_mapping_error(ibdev, dma_addr)) {
+ srp_exit_cmd_priv(shost, cmd);
+ goto out;
}
+
+ req->indirect_dma_addr = dma_addr;
ret = 0;
out:
@@ -1067,10 +1052,6 @@ static void srp_remove_target(struct srp_target_port *target)
}
cancel_work_sync(&target->tl_err_work);
srp_rport_put(target->rport);
- for (i = 0; i < target->ch_count; i++) {
- ch = &target->ch[i];
- srp_free_req_data(target, ch);
- }
kfree(target->ch);
target->ch = NULL;
@@ -1289,22 +1270,32 @@ static void srp_finish_req(struct srp_rdma_ch *ch, struct srp_request *req,
}
}
-static void srp_terminate_io(struct srp_rport *rport)
+struct srp_terminate_context {
+ struct srp_target_port *srp_target;
+ int scsi_result;
+};
+
+static bool srp_terminate_cmd(struct scsi_cmnd *scmnd, void *context_ptr,
+ bool reserved)
{
- struct srp_target_port *target = rport->lld_data;
- struct srp_rdma_ch *ch;
- int i, j;
+ struct srp_terminate_context *context = context_ptr;
+ struct srp_target_port *target = context->srp_target;
+ u32 tag = blk_mq_unique_tag(scmnd->request);
+ struct srp_rdma_ch *ch = &target->ch[blk_mq_unique_tag_to_hwq(tag)];
+ struct srp_request *req = scsi_cmd_priv(scmnd);
- for (i = 0; i < target->ch_count; i++) {
- ch = &target->ch[i];
+ srp_finish_req(ch, req, NULL, context->scsi_result);
- for (j = 0; j < target->req_ring_size; ++j) {
- struct srp_request *req = &ch->req_ring[j];
+ return true;
+}
- srp_finish_req(ch, req, NULL,
- DID_TRANSPORT_FAILFAST << 16);
- }
- }
+static void srp_terminate_io(struct srp_rport *rport)
+{
+ struct srp_target_port *target = rport->lld_data;
+ struct srp_terminate_context context = { .srp_target = target,
+ .scsi_result = DID_TRANSPORT_FAILFAST << 16 };
+
+ scsi_host_busy_iter(target->scsi_host, srp_terminate_cmd, &context);
}
/* Calculate maximum initiator to target information unit length. */
@@ -1360,13 +1351,12 @@ static int srp_rport_reconnect(struct srp_rport *rport)
ch = &target->ch[i];
ret += srp_new_cm_id(ch);
}
- for (i = 0; i < target->ch_count; i++) {
- ch = &target->ch[i];
- for (j = 0; j < target->req_ring_size; ++j) {
- struct srp_request *req = &ch->req_ring[j];
+ {
+ struct srp_terminate_context context = {
+ .srp_target = target, .scsi_result = DID_RESET << 16};
- srp_finish_req(ch, req, NULL, DID_RESET << 16);
- }
+ scsi_host_busy_iter(target->scsi_host, srp_terminate_cmd,
+ &context);
}
for (i = 0; i < target->ch_count; i++) {
ch = &target->ch[i];
@@ -1962,13 +1952,10 @@ static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)
spin_unlock_irqrestore(&ch->lock, flags);
} else {
scmnd = scsi_host_find_tag(target->scsi_host, rsp->tag);
- if (scmnd && scmnd->host_scribble) {
- req = (void *)scmnd->host_scribble;
+ if (scmnd) {
+ req = scsi_cmd_priv(scmnd);
scmnd = srp_claim_req(ch, req, NULL, scmnd);
} else {
- scmnd = NULL;
- }
- if (!scmnd) {
shost_printk(KERN_ERR, target->scsi_host,
"Null scmnd for RSP w/tag %#016llx received on ch %td / QP %#x\n",
rsp->tag, ch - target->ch, ch->qp->qp_num);
@@ -2000,7 +1987,6 @@ static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)
srp_free_req(ch, req, scmnd,
be32_to_cpu(rsp->req_lim_delta));
- scmnd->host_scribble = NULL;
scmnd->scsi_done(scmnd);
}
}
@@ -2168,13 +2154,12 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
{
struct srp_target_port *target = host_to_target(shost);
struct srp_rdma_ch *ch;
- struct srp_request *req;
+ struct srp_request *req = scsi_cmd_priv(scmnd);
struct srp_iu *iu;
struct srp_cmd *cmd;
struct ib_device *dev;
unsigned long flags;
u32 tag;
- u16 idx;
int len, ret;
scmnd->result = srp_chkready(target->rport);
@@ -2184,10 +2169,6 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
WARN_ON_ONCE(scmnd->request->tag < 0);
tag = blk_mq_unique_tag(scmnd->request);
ch = &target->ch[blk_mq_unique_tag_to_hwq(tag)];
- idx = blk_mq_unique_tag_to_tag(tag);
- WARN_ONCE(idx >= target->req_ring_size, "%s: tag %#x: idx %d >= %d\n",
- dev_name(&shost->shost_gendev), tag, idx,
- target->req_ring_size);
spin_lock_irqsave(&ch->lock, flags);
iu = __srp_get_tx_iu(ch, SRP_IU_CMD);
@@ -2196,13 +2177,10 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
if (!iu)
goto err;
- req = &ch->req_ring[idx];
dev = target->srp_host->srp_dev->dev;
ib_dma_sync_single_for_cpu(dev, iu->dma, ch->max_it_iu_len,
DMA_TO_DEVICE);
- scmnd->host_scribble = (void *) req;
-
cmd = iu->buf;
memset(cmd, 0, sizeof *cmd);
@@ -3083,6 +3061,8 @@ static struct scsi_host_template srp_template = {
.target_alloc = srp_target_alloc,
.slave_configure = srp_slave_configure,
.info = srp_target_info,
+ .init_cmd_priv = srp_init_cmd_priv,
+ .exit_cmd_priv = srp_exit_cmd_priv,
.queuecommand = srp_queuecommand,
.change_queue_depth = srp_change_queue_depth,
.eh_timed_out = srp_timed_out,
@@ -3096,6 +3076,7 @@ static struct scsi_host_template srp_template = {
.cmd_per_lun = SRP_DEFAULT_CMD_SQ_SIZE,
.shost_attrs = srp_host_attrs,
.track_queue_depth = 1,
+ .cmd_size = sizeof(struct srp_request),
};
static int srp_sdev_count(struct Scsi_Host *host)
@@ -3675,8 +3656,6 @@ static ssize_t srp_create_target(struct device *dev,
if (ret)
goto out;
- target->req_ring_size = target->queue_size - SRP_TSK_MGMT_SQ_SIZE;
-
if (!srp_conn_unique(target->srp_host, target)) {
if (target->using_rdma_cm) {
shost_printk(KERN_INFO, target->scsi_host,
@@ -3779,10 +3758,6 @@ static ssize_t srp_create_target(struct device *dev,
if (ret)
goto err_disconnect;
- ret = srp_alloc_req_data(ch);
- if (ret)
- goto err_disconnect;
-
ret = srp_connect_ch(ch, max_iu_len, multich);
if (ret) {
char dst[64];
@@ -3801,7 +3776,6 @@ static ssize_t srp_create_target(struct device *dev,
goto free_ch;
} else {
srp_free_ch_ib(target, ch);
- srp_free_req_data(target, ch);
target->ch_count = ch - target->ch;
goto connected;
}
@@ -3862,7 +3836,6 @@ static ssize_t srp_create_target(struct device *dev,
for (i = 0; i < target->ch_count; i++) {
ch = &target->ch[i];
srp_free_ch_ib(target, ch);
- srp_free_req_data(target, ch);
}
kfree(target->ch);
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index 6818cac0a3b7..abccddeea1e3 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -174,7 +174,6 @@ struct srp_rdma_ch {
struct srp_iu **tx_ring;
struct srp_iu **rx_ring;
- struct srp_request *req_ring;
int comp_vector;
u64 tsk_mgmt_tag;
@@ -220,7 +219,6 @@ struct srp_target_port {
int mr_pool_size;
int mr_per_cmd;
int queue_size;
- int req_ring_size;
int comp_vector;
int tl_retry_count;
