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qla2xxx: Convert to percpu_ida session tag pre-allocation
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This patch converts qla2xxx target code to use generic percpu_ida
tag allocation provided by target-core, thus removing the original
kmem_cache_zalloc() for each struct qla_tgt_cmd descriptor in the
incoming ATIO packet fast-path.

This includes the conversion of qlt_handle_cmd_for_atio() to perform
qla_tgt_sess lookup before dispatching a command descriptor into
qla_tgt_wq process context, along with handling the case where no
active session exists, and subsequently kicking off a seperate
process context for qlt_create_sess_from_atio() to create a new one.

It also includes moving tag allocation into generic code within
qlt_get_tag(), so that the same logic can be shared between
qlt_handle_cmd_for_atio() + qlt_create_sess_from_atio() contexts.
Also, __qlt_do_work() has been made generic between both normal
process context in qlt_do_work() + qlt_create_sess_from_atio().

Next, update qlt_free_cmd() to release the percpu-ida tags, and
drop the now-unused global qla_tgt_cmd_cachep.

Finally in tcm_qla2xxx code, tcm_qla2xxx_check_initiator_node_acl()
has been updated to use transport_init_session_tags() along with a
hardcoded TCM_QLA2XXX_DEFAULT_TAGS=2088 as the number of qla_tgt_cmd
descriptors to pre-allocate per qla_tgt_sess instance.

(Use ha->fw_xcb_count if available to calculate num_tags, and
 also factor in extra pad tags - Quinn)

Cc: Saurav Kashyap <saurav.kashyap@qlogic.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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Nicholas Bellinger committed Jun 4, 2014
1 parent e6dc783 commit 51a07f8
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Showing 4 changed files with 147 additions and 65 deletions.
195 changes: 131 additions & 64 deletions drivers/scsi/qla2xxx/qla_target.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -104,7 +104,6 @@ static void qlt_reject_free_srr_imm(struct scsi_qla_host *ha,
/*
* Global Variables
*/
static struct kmem_cache *qla_tgt_cmd_cachep;
static struct kmem_cache *qla_tgt_mgmt_cmd_cachep;
static mempool_t *qla_tgt_mgmt_cmd_mempool;
static struct workqueue_struct *qla_tgt_wq;
Expand Down Expand Up @@ -2165,11 +2164,18 @@ static void qlt_send_term_exchange(struct scsi_qla_host *vha,

void qlt_free_cmd(struct qla_tgt_cmd *cmd)
{
struct qla_tgt_sess *sess = cmd->sess;

BUG_ON(cmd->sg_mapped);

if (unlikely(cmd->free_sg))
kfree(cmd->sg);
kmem_cache_free(qla_tgt_cmd_cachep, cmd);

if (!sess || !sess->se_sess) {
WARN_ON(1);
return;
}
percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
}
EXPORT_SYMBOL(qlt_free_cmd);

Expand Down Expand Up @@ -2489,13 +2495,12 @@ static struct qla_tgt_sess *qlt_make_local_sess(struct scsi_qla_host *,
/*
* Process context for I/O path into tcm_qla2xxx code
*/
static void qlt_do_work(struct work_struct *work)
static void __qlt_do_work(struct qla_tgt_cmd *cmd)
{
struct qla_tgt_cmd *cmd = container_of(work, struct qla_tgt_cmd, work);
scsi_qla_host_t *vha = cmd->vha;
struct qla_hw_data *ha = vha->hw;
struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
struct qla_tgt_sess *sess = NULL;
struct qla_tgt_sess *sess = cmd->sess;
struct atio_from_isp *atio = &cmd->atio;
unsigned char *cdb;
unsigned long flags;
Expand All @@ -2505,41 +2510,6 @@ static void qlt_do_work(struct work_struct *work)
if (tgt->tgt_stop)
goto out_term;

spin_lock_irqsave(&ha->hardware_lock, flags);
sess = ha->tgt.tgt_ops->find_sess_by_s_id(vha,
atio->u.isp24.fcp_hdr.s_id);
/* Do kref_get() before dropping qla_hw_data->hardware_lock. */
if (sess)
kref_get(&sess->se_sess->sess_kref);
spin_unlock_irqrestore(&ha->hardware_lock, flags);

if (unlikely(!sess)) {
uint8_t *s_id = atio->u.isp24.fcp_hdr.s_id;

ql_dbg(ql_dbg_tgt_mgt, vha, 0xf022,
"qla_target(%d): Unable to find wwn login"
" (s_id %x:%x:%x), trying to create it manually\n",
vha->vp_idx, s_id[0], s_id[1], s_id[2]);

if (atio->u.raw.entry_count > 1) {
ql_dbg(ql_dbg_tgt_mgt, vha, 0xf023,
"Dropping multy entry cmd %p\n", cmd);
goto out_term;
}

mutex_lock(&vha->vha_tgt.tgt_mutex);
sess = qlt_make_local_sess(vha, s_id);
/* sess has an extra creation ref. */
mutex_unlock(&vha->vha_tgt.tgt_mutex);

if (!sess)
goto out_term;
}

cmd->sess = sess;
cmd->loop_id = sess->loop_id;
cmd->conf_compl_supported = sess->conf_compl_supported;

cdb = &atio->u.isp24.fcp_cmnd.cdb[0];
cmd->tag = atio->u.isp24.exchange_addr;
cmd->unpacked_lun = scsilun_to_int(
Expand All @@ -2566,8 +2536,8 @@ static void qlt_do_work(struct work_struct *work)
"qla_target: START qla command: %p lun: 0x%04x (tag %d)\n",
cmd, cmd->unpacked_lun, cmd->tag);

ret = vha->hw->tgt.tgt_ops->handle_cmd(vha, cmd, cdb, data_length,
fcp_task_attr, data_dir, bidi);
ret = ha->tgt.tgt_ops->handle_cmd(vha, cmd, cdb, data_length,
fcp_task_attr, data_dir, bidi);
if (ret != 0)
goto out_term;
/*
Expand All @@ -2586,17 +2556,114 @@ static void qlt_do_work(struct work_struct *work)
*/
spin_lock_irqsave(&ha->hardware_lock, flags);
qlt_send_term_exchange(vha, NULL, &cmd->atio, 1);
kmem_cache_free(qla_tgt_cmd_cachep, cmd);
if (sess)
percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
ha->tgt.tgt_ops->put_sess(sess);
spin_unlock_irqrestore(&ha->hardware_lock, flags);
}

static void qlt_do_work(struct work_struct *work)
{
struct qla_tgt_cmd *cmd = container_of(work, struct qla_tgt_cmd, work);

__qlt_do_work(cmd);
}

static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha,
struct qla_tgt_sess *sess,
struct atio_from_isp *atio)
{
struct se_session *se_sess = sess->se_sess;
struct qla_tgt_cmd *cmd;
int tag;

tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
if (tag < 0)
return NULL;

cmd = &((struct qla_tgt_cmd *)se_sess->sess_cmd_map)[tag];
memset(cmd, 0, sizeof(struct qla_tgt_cmd));

memcpy(&cmd->atio, atio, sizeof(*atio));
cmd->state = QLA_TGT_STATE_NEW;
cmd->tgt = vha->vha_tgt.qla_tgt;
cmd->vha = vha;
cmd->se_cmd.map_tag = tag;
cmd->sess = sess;
cmd->loop_id = sess->loop_id;
cmd->conf_compl_supported = sess->conf_compl_supported;

return cmd;
}

static void qlt_send_busy(struct scsi_qla_host *, struct atio_from_isp *,
uint16_t);

static void qlt_create_sess_from_atio(struct work_struct *work)
{
struct qla_tgt_sess_op *op = container_of(work,
struct qla_tgt_sess_op, work);
scsi_qla_host_t *vha = op->vha;
struct qla_hw_data *ha = vha->hw;
struct qla_tgt_sess *sess;
struct qla_tgt_cmd *cmd;
unsigned long flags;
uint8_t *s_id = op->atio.u.isp24.fcp_hdr.s_id;

ql_dbg(ql_dbg_tgt_mgt, vha, 0xf022,
"qla_target(%d): Unable to find wwn login"
" (s_id %x:%x:%x), trying to create it manually\n",
vha->vp_idx, s_id[0], s_id[1], s_id[2]);

if (op->atio.u.raw.entry_count > 1) {
ql_dbg(ql_dbg_tgt_mgt, vha, 0xf023,
"Dropping multy entry atio %p\n", &op->atio);
goto out_term;
}

mutex_lock(&vha->vha_tgt.tgt_mutex);
sess = qlt_make_local_sess(vha, s_id);
/* sess has an extra creation ref. */
mutex_unlock(&vha->vha_tgt.tgt_mutex);

if (!sess)
goto out_term;
/*
* Now obtain a pre-allocated session tag using the original op->atio
* packet header, and dispatch into __qlt_do_work() using the existing
* process context.
*/
cmd = qlt_get_tag(vha, sess, &op->atio);
if (!cmd) {
spin_lock_irqsave(&ha->hardware_lock, flags);
qlt_send_busy(vha, &op->atio, SAM_STAT_BUSY);
ha->tgt.tgt_ops->put_sess(sess);
spin_unlock_irqrestore(&ha->hardware_lock, flags);
kfree(op);
return;
}
/*
* __qlt_do_work() will call ha->tgt.tgt_ops->put_sess() to release
* the extra reference taken above by qlt_make_local_sess()
*/
__qlt_do_work(cmd);
kfree(op);
return;

out_term:
spin_lock_irqsave(&ha->hardware_lock, flags);
qlt_send_term_exchange(vha, NULL, &op->atio, 1);
spin_unlock_irqrestore(&ha->hardware_lock, flags);
kfree(op);

}

/* ha->hardware_lock supposed to be held on entry */
static int qlt_handle_cmd_for_atio(struct scsi_qla_host *vha,
struct atio_from_isp *atio)
{
struct qla_hw_data *ha = vha->hw;
struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
struct qla_tgt_sess *sess;
struct qla_tgt_cmd *cmd;

if (unlikely(tgt->tgt_stop)) {
Expand All @@ -2605,18 +2672,31 @@ static int qlt_handle_cmd_for_atio(struct scsi_qla_host *vha,
return -EFAULT;
}

cmd = kmem_cache_zalloc(qla_tgt_cmd_cachep, GFP_ATOMIC);
sess = ha->tgt.tgt_ops->find_sess_by_s_id(vha, atio->u.isp24.fcp_hdr.s_id);
if (unlikely(!sess)) {
struct qla_tgt_sess_op *op = kzalloc(sizeof(struct qla_tgt_sess_op),
GFP_ATOMIC);
if (!op)
return -ENOMEM;

memcpy(&op->atio, atio, sizeof(*atio));
INIT_WORK(&op->work, qlt_create_sess_from_atio);
queue_work(qla_tgt_wq, &op->work);
return 0;
}
/*
* Do kref_get() before returning + dropping qla_hw_data->hardware_lock.
*/
kref_get(&sess->se_sess->sess_kref);

cmd = qlt_get_tag(vha, sess, atio);
if (!cmd) {
ql_dbg(ql_dbg_tgt_mgt, vha, 0xf05e,
"qla_target(%d): Allocation of cmd failed\n", vha->vp_idx);
ha->tgt.tgt_ops->put_sess(sess);
return -ENOMEM;
}

memcpy(&cmd->atio, atio, sizeof(*atio));
cmd->state = QLA_TGT_STATE_NEW;
cmd->tgt = vha->vha_tgt.qla_tgt;
cmd->vha = vha;

INIT_WORK(&cmd->work, qlt_do_work);
queue_work(qla_tgt_wq, &cmd->work);
return 0;
Expand Down Expand Up @@ -4911,23 +4991,13 @@ int __init qlt_init(void)
if (!QLA_TGT_MODE_ENABLED())
return 0;

qla_tgt_cmd_cachep = kmem_cache_create("qla_tgt_cmd_cachep",
sizeof(struct qla_tgt_cmd), __alignof__(struct qla_tgt_cmd), 0,
NULL);
if (!qla_tgt_cmd_cachep) {
ql_log(ql_log_fatal, NULL, 0xe06c,
"kmem_cache_create for qla_tgt_cmd_cachep failed\n");
return -ENOMEM;
}

qla_tgt_mgmt_cmd_cachep = kmem_cache_create("qla_tgt_mgmt_cmd_cachep",
sizeof(struct qla_tgt_mgmt_cmd), __alignof__(struct
qla_tgt_mgmt_cmd), 0, NULL);
if (!qla_tgt_mgmt_cmd_cachep) {
ql_log(ql_log_fatal, NULL, 0xe06d,
"kmem_cache_create for qla_tgt_mgmt_cmd_cachep failed\n");
ret = -ENOMEM;
goto out;
return -ENOMEM;
}

qla_tgt_mgmt_cmd_mempool = mempool_create(25, mempool_alloc_slab,
Expand Down Expand Up @@ -4955,8 +5025,6 @@ int __init qlt_init(void)
mempool_destroy(qla_tgt_mgmt_cmd_mempool);
out_mgmt_cmd_cachep:
kmem_cache_destroy(qla_tgt_mgmt_cmd_cachep);
out:
kmem_cache_destroy(qla_tgt_cmd_cachep);
return ret;
}

Expand All @@ -4968,5 +5036,4 @@ void qlt_exit(void)
destroy_workqueue(qla_tgt_wq);
mempool_destroy(qla_tgt_mgmt_cmd_mempool);
kmem_cache_destroy(qla_tgt_mgmt_cmd_cachep);
kmem_cache_destroy(qla_tgt_cmd_cachep);
}
6 changes: 6 additions & 0 deletions drivers/scsi/qla2xxx/qla_target.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -805,6 +805,12 @@ struct qla_tgt {
struct list_head tgt_list_entry;
};

struct qla_tgt_sess_op {
struct scsi_qla_host *vha;
struct atio_from_isp atio;
struct work_struct work;
};

/*
* Equivilant to IT Nexus (Initiator-Target)
*/
Expand Down
6 changes: 5 additions & 1 deletion drivers/scsi/qla2xxx/tcm_qla2xxx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1465,6 +1465,8 @@ static int tcm_qla2xxx_check_initiator_node_acl(
struct qla_tgt_sess *sess = qla_tgt_sess;
unsigned char port_name[36];
unsigned long flags;
int num_tags = (ha->fw_xcb_count) ? ha->fw_xcb_count :
TCM_QLA2XXX_DEFAULT_TAGS;

lport = vha->vha_tgt.target_lport_ptr;
if (!lport) {
Expand All @@ -1482,7 +1484,9 @@ static int tcm_qla2xxx_check_initiator_node_acl(
}
se_tpg = &tpg->se_tpg;

se_sess = transport_init_session(TARGET_PROT_NORMAL);
se_sess = transport_init_session_tags(num_tags,
sizeof(struct qla_tgt_cmd),
TARGET_PROT_NORMAL);
if (IS_ERR(se_sess)) {
pr_err("Unable to initialize struct se_session\n");
return PTR_ERR(se_sess);
Expand Down
5 changes: 5 additions & 0 deletions drivers/scsi/qla2xxx/tcm_qla2xxx.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,11 @@
#define TCM_QLA2XXX_VERSION "v0.1"
/* length of ASCII WWPNs including pad */
#define TCM_QLA2XXX_NAMELEN 32
/*
* Number of pre-allocated per-session tags, based upon the worst-case
* per port number of iocbs
*/
#define TCM_QLA2XXX_DEFAULT_TAGS 2088

#include "qla_target.h"

Expand Down

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