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IB/srp: Preparation for transmit ring response allocation
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The transmit ring in ib_srp (srp_target.tx_ring) is currently only used
for allocating requests sent by the initiator to the target. This patch
prepares using that ring for allocation of both requests and responses.
Also, this patch differentiates the uses of SRP_SQ_SIZE, increases the
size of the IB send completion queue by one element and reserves one
transmit ring slot for SRP_TSK_MGMT requests.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
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Bart Van Assche authored and Roland Dreier committed Oct 23, 2010
1 parent fb50a83 commit dd5e6e3
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Showing 2 changed files with 25 additions and 15 deletions.
27 changes: 15 additions & 12 deletions drivers/infiniband/ulp/srp/ib_srp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -291,7 +291,7 @@ static void srp_free_target_ib(struct srp_target_port *target)

for (i = 0; i < SRP_RQ_SIZE; ++i)
srp_free_iu(target->srp_host, target->rx_ring[i]);
for (i = 0; i < SRP_SQ_SIZE + 1; ++i)
for (i = 0; i < SRP_SQ_SIZE; ++i)
srp_free_iu(target->srp_host, target->tx_ring[i]);
}

Expand Down Expand Up @@ -822,7 +822,7 @@ static int srp_post_recv(struct srp_target_port *target)

spin_lock_irqsave(target->scsi_host->host_lock, flags);

next = target->rx_head & (SRP_RQ_SIZE - 1);
next = target->rx_head & SRP_RQ_MASK;
wr.wr_id = next;
iu = target->rx_ring[next];

Expand Down Expand Up @@ -989,19 +989,19 @@ static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target,
enum srp_request_type req_type)
{
s32 min = (req_type == SRP_REQ_TASK_MGMT) ? 1 : 2;
s32 rsv = (req_type == SRP_REQ_TASK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;

srp_send_completion(target->send_cq, target);

if (target->tx_head - target->tx_tail >= SRP_SQ_SIZE)
return NULL;

if (target->req_lim < min) {
if (target->req_lim <= rsv) {
++target->zero_req_lim;
return NULL;
}

return target->tx_ring[target->tx_head & SRP_SQ_SIZE];
return target->tx_ring[target->tx_head & SRP_SQ_MASK];
}

/*
Expand All @@ -1020,7 +1020,7 @@ static int __srp_post_send(struct srp_target_port *target,
list.lkey = target->srp_host->srp_dev->mr->lkey;

wr.next = NULL;
wr.wr_id = target->tx_head & SRP_SQ_SIZE;
wr.wr_id = target->tx_head & SRP_SQ_MASK;
wr.sg_list = &list;
wr.num_sge = 1;
wr.opcode = IB_WR_SEND;
Expand Down Expand Up @@ -1121,7 +1121,7 @@ static int srp_alloc_iu_bufs(struct srp_target_port *target)
goto err;
}

for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
for (i = 0; i < SRP_SQ_SIZE; ++i) {
target->tx_ring[i] = srp_alloc_iu(target->srp_host,
srp_max_iu_len,
GFP_KERNEL, DMA_TO_DEVICE);
Expand All @@ -1137,7 +1137,7 @@ static int srp_alloc_iu_bufs(struct srp_target_port *target)
target->rx_ring[i] = NULL;
}

for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
for (i = 0; i < SRP_SQ_SIZE; ++i) {
srp_free_iu(target->srp_host, target->tx_ring[i]);
target->tx_ring[i] = NULL;
}
Expand Down Expand Up @@ -1626,9 +1626,9 @@ static struct scsi_host_template srp_template = {
.eh_abort_handler = srp_abort,
.eh_device_reset_handler = srp_reset_device,
.eh_host_reset_handler = srp_reset_host,
.can_queue = SRP_SQ_SIZE,
.can_queue = SRP_CMD_SQ_SIZE,
.this_id = -1,
.cmd_per_lun = SRP_SQ_SIZE,
.cmd_per_lun = SRP_CMD_SQ_SIZE,
.use_clustering = ENABLE_CLUSTERING,
.shost_attrs = srp_host_attrs
};
Expand Down Expand Up @@ -1813,7 +1813,7 @@ static int srp_parse_options(const char *buf, struct srp_target_port *target)
printk(KERN_WARNING PFX "bad max cmd_per_lun parameter '%s'\n", p);
goto out;
}
target->scsi_host->cmd_per_lun = min(token, SRP_SQ_SIZE);
target->scsi_host->cmd_per_lun = min(token, SRP_CMD_SQ_SIZE);
break;

case SRP_OPT_IO_CLASS:
Expand Down Expand Up @@ -1891,7 +1891,7 @@ static ssize_t srp_create_target(struct device *dev,

INIT_LIST_HEAD(&target->free_reqs);
INIT_LIST_HEAD(&target->req_queue);
for (i = 0; i < SRP_SQ_SIZE; ++i) {
for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
target->req_ring[i].index = i;
list_add_tail(&target->req_ring[i].list, &target->free_reqs);
}
Expand Down Expand Up @@ -2159,6 +2159,9 @@ static int __init srp_init_module(void)
{
int ret;

BUILD_BUG_ON_NOT_POWER_OF_2(SRP_SQ_SIZE);
BUILD_BUG_ON_NOT_POWER_OF_2(SRP_RQ_SIZE);

if (srp_sg_tablesize > 255) {
printk(KERN_WARNING PFX "Clamping srp_sg_tablesize to 255\n");
srp_sg_tablesize = 255;
Expand Down
13 changes: 10 additions & 3 deletions drivers/infiniband/ulp/srp/ib_srp.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -59,7 +59,14 @@ enum {

SRP_RQ_SHIFT = 6,
SRP_RQ_SIZE = 1 << SRP_RQ_SHIFT,
SRP_SQ_SIZE = SRP_RQ_SIZE - 1,
SRP_RQ_MASK = SRP_RQ_SIZE - 1,

SRP_SQ_SIZE = SRP_RQ_SIZE,
SRP_SQ_MASK = SRP_SQ_SIZE - 1,
SRP_RSP_SQ_SIZE = 1,
SRP_REQ_SQ_SIZE = SRP_SQ_SIZE - SRP_RSP_SQ_SIZE,
SRP_TSK_MGMT_SQ_SIZE = 1,
SRP_CMD_SQ_SIZE = SRP_REQ_SQ_SIZE - SRP_TSK_MGMT_SQ_SIZE,

SRP_TAG_TSK_MGMT = 1 << (SRP_RQ_SHIFT + 1),

Expand Down Expand Up @@ -144,11 +151,11 @@ struct srp_target_port {

unsigned tx_head;
unsigned tx_tail;
struct srp_iu *tx_ring[SRP_SQ_SIZE + 1];
struct srp_iu *tx_ring[SRP_SQ_SIZE];

struct list_head free_reqs;
struct list_head req_queue;
struct srp_request req_ring[SRP_SQ_SIZE];
struct srp_request req_ring[SRP_CMD_SQ_SIZE];

struct work_struct work;

Expand Down

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