While dev_to_shost() is a solid implementation of a runtime type
identification (RTTI) scheme, within the scope of a Scsi_Host
object (e.g. representing a HBA) the answer is always the same!
So cache the answer for the sas_phy and sas_rphy cases. This
should marginally improve the speed of about half the functions
defined in scsi_transport_sas.c .
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
drivers/scsi/scsi_transport_sas.c | 40 +++++++++++++++----------------
include/scsi/scsi_transport_sas.h | 8 +++++--
2 files changed, 26 insertions(+), 22 deletions(-)
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index c9abed8429c9..8d52de5d0957 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -171,7 +171,7 @@ static struct sas_end_device *sas_sdev_to_rdev(struct scsi_device *sdev)
static int sas_smp_dispatch(struct bsg_job *job)
{
- struct Scsi_Host *shost = dev_to_shost(job->dev);
+ struct Scsi_Host *shost;
struct sas_rphy *rphy = NULL;
if (!scsi_is_host_device(job->dev))
@@ -183,6 +183,7 @@ static int sas_smp_dispatch(struct bsg_job *job)
return 0;
}
+ shost = rphy->shost;
to_sas_internal(shost->transportt)->f->smp_handler(job, shost, rphy);
return 0;
}
@@ -462,7 +463,7 @@ store_sas_phy_##field(struct device *dev, \
const char *buf, size_t count) \
{ \
struct sas_phy *phy = transport_class_to_phy(dev); \
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent); \
+ struct Scsi_Host *shost = phy->shost; \
struct sas_internal *i = to_sas_internal(shost->transportt); \
u32 value; \
struct sas_phy_linkrates rates = {0}; \
@@ -494,7 +495,7 @@ show_sas_phy_##field(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct sas_phy *phy = transport_class_to_phy(dev); \
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent); \
+ struct Scsi_Host *shost = phy->shost; \
struct sas_internal *i = to_sas_internal(shost->transportt); \
int error; \
\
@@ -525,7 +526,7 @@ static ssize_t do_sas_phy_enable(struct device *dev,
size_t count, int enable)
{
struct sas_phy *phy = transport_class_to_phy(dev);
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
+ struct Scsi_Host *shost = phy->shost;
struct sas_internal *i = to_sas_internal(shost->transportt);
int error;
@@ -573,8 +574,7 @@ static ssize_t
do_sas_phy_reset(struct device *dev, size_t count, int hard_reset)
{
struct sas_phy *phy = transport_class_to_phy(dev);
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
- struct sas_internal *i = to_sas_internal(shost->transportt);
+ struct sas_internal *i = to_sas_internal(phy->shost->transportt);
int error;
error = i->f->phy_reset(phy, hard_reset);
@@ -621,8 +621,7 @@ static int sas_phy_setup(struct transport_container *tc, struct device *dev,
struct device *cdev)
{
struct sas_phy *phy = dev_to_phy(dev);
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
- struct sas_internal *i = to_sas_internal(shost->transportt);
+ struct sas_internal *i = to_sas_internal(phy->shost->transportt);
if (i->f->phy_setup)
i->f->phy_setup(phy);
@@ -640,7 +639,7 @@ static int sas_phy_match(struct attribute_container *cont, struct device *dev)
if (!scsi_is_sas_phy(dev))
return 0;
- shost = dev_to_shost(dev->parent);
+ shost = dev_to_phy(dev)->shost;
if (!shost->transportt)
return 0;
@@ -655,8 +654,7 @@ static int sas_phy_match(struct attribute_container *cont, struct device *dev)
static void sas_phy_release(struct device *dev)
{
struct sas_phy *phy = dev_to_phy(dev);
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
- struct sas_internal *i = to_sas_internal(shost->transportt);
+ struct sas_internal *i = to_sas_internal(phy->shost->transportt);
if (i->f->phy_release)
i->f->phy_release(phy);
@@ -687,6 +685,7 @@ struct sas_phy *sas_phy_alloc(struct device *parent, int number)
phy->number = number;
phy->enabled = 1;
+ phy->shost = shost;
device_initialize(&phy->dev);
phy->dev.parent = get_device(parent);
@@ -806,6 +805,7 @@ static int sas_port_match(struct attribute_container *cont, struct device *dev)
if (!scsi_is_sas_port(dev))
return 0;
+ /* Could dev_to_sas_port(dev) and if port non-NULL use rphy->shost */
shost = dev_to_shost(dev->parent);
if (!shost->transportt)
@@ -1180,8 +1180,7 @@ show_sas_rphy_enclosure_identifier(struct device *dev,
{
struct sas_rphy *rphy = transport_class_to_rphy(dev);
struct sas_phy *phy = dev_to_phy(rphy->dev.parent);
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
- struct sas_internal *i = to_sas_internal(shost->transportt);
+ struct sas_internal *i = to_sas_internal(phy->shost->transportt);
u64 identifier;
int error;
@@ -1200,8 +1199,7 @@ show_sas_rphy_bay_identifier(struct device *dev,
{
struct sas_rphy *rphy = transport_class_to_rphy(dev);
struct sas_phy *phy = dev_to_phy(rphy->dev.parent);
- struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
- struct sas_internal *i = to_sas_internal(shost->transportt);
+ struct sas_internal *i = to_sas_internal(phy->shost->transportt);
int val;
val = i->f->get_bay_identifier(rphy);
@@ -1327,7 +1325,7 @@ static int sas_rphy_match(struct attribute_container *cont, struct device *dev)
if (!scsi_is_sas_rphy(dev))
return 0;
- shost = dev_to_shost(dev->parent->parent);
+ shost = dev_to_rphy(dev)->shost;
if (!shost->transportt)
return 0;
@@ -1348,8 +1346,8 @@ static int sas_end_dev_match(struct attribute_container *cont,
if (!scsi_is_sas_rphy(dev))
return 0;
- shost = dev_to_shost(dev->parent->parent);
rphy = dev_to_rphy(dev);
+ shost = rphy->shost;
if (!shost->transportt)
return 0;
@@ -1371,8 +1369,8 @@ static int sas_expander_match(struct attribute_container *cont,
if (!scsi_is_sas_rphy(dev))
return 0;
- shost = dev_to_shost(dev->parent->parent);
rphy = dev_to_rphy(dev);
+ shost = rphy->shost;
if (!shost->transportt)
return 0;
@@ -1436,6 +1434,7 @@ struct sas_rphy *sas_end_device_alloc(struct sas_port *parent)
}
device_initialize(&rdev->rphy.dev);
+ rdev->rphy.shost = shost;
rdev->rphy.dev.parent = get_device(&parent->dev);
rdev->rphy.dev.release = sas_end_device_release;
if (scsi_is_sas_expander_device(parent->dev.parent)) {
@@ -1480,6 +1479,7 @@ struct sas_rphy *sas_expander_alloc(struct sas_port *parent,
}
device_initialize(&rdev->rphy.dev);
+ rdev->rphy.shost = shost;
rdev->rphy.dev.parent = get_device(&parent->dev);
rdev->rphy.dev.release = sas_expander_release;
mutex_lock(&sas_host->lock);
@@ -1504,7 +1504,7 @@ EXPORT_SYMBOL(sas_expander_alloc);
int sas_rphy_add(struct sas_rphy *rphy)
{
struct sas_port *parent = dev_to_sas_port(rphy->dev.parent);
- struct Scsi_Host *shost = dev_to_shost(parent->dev.parent);
+ struct Scsi_Host *shost = rphy->shost;
struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
struct sas_identify *identify = &rphy->identify;
int error;
@@ -1563,7 +1563,7 @@ EXPORT_SYMBOL(sas_rphy_add);
void sas_rphy_free(struct sas_rphy *rphy)
{
struct device *dev = &rphy->dev;
- struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent->parent);
+ struct Scsi_Host *shost = rphy->shost;
struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
mutex_lock(&sas_host->lock);
diff --git a/include/scsi/scsi_transport_sas.h b/include/scsi/scsi_transport_sas.h
index 05ec927a3c72..9f4c50358f82 100644
--- a/include/scsi/scsi_transport_sas.h
+++ b/include/scsi/scsi_transport_sas.h
@@ -9,6 +9,7 @@
#include <linux/bsg-lib.h>
struct scsi_transport_template;
+struct Scsi_Host;
struct sas_rphy;
struct request;
@@ -80,6 +81,8 @@ struct sas_phy {
/* for the list of phys belonging to a port */
struct list_head port_siblings;
+ struct Scsi_Host *shost; /* cache to avoid dev_to_shost() walks */
+
/* available to the lldd */
void *hostdata;
};
@@ -89,7 +92,7 @@ struct sas_phy {
#define transport_class_to_phy(dev) \
dev_to_phy((dev)->parent)
#define phy_to_shost(phy) \
- dev_to_shost((phy)->dev.parent)
+ ((phy)->shost)
struct request_queue;
struct sas_rphy {
@@ -97,6 +100,7 @@ struct sas_rphy {
struct sas_identify identify;
struct list_head list;
struct request_queue *q;
+ struct Scsi_Host *shost; /* cache to avoid dev_to_shost() walks */
u32 scsi_target_id;
};
@@ -105,7 +109,7 @@ struct sas_rphy {
#define transport_class_to_rphy(dev) \
dev_to_rphy((dev)->parent)
#define rphy_to_shost(rphy) \
- dev_to_shost((rphy)->dev.parent)
+ ((rphy)->shost)
#define target_to_rphy(targ) \
dev_to_rphy((targ)->dev.parent)
--
2.25.1
