This patch will modify the scsi and ata subsystem to allow
users to set a power management policy for the link.
libata drivers can define a function (enable_pm) that will
perform hardware specific actions to enable whatever power
management policy the user sets up if the driver supports
it. This power management policy will be activated after
all disks have been enumerated and intialized.
The scsi subsystem will create a new sysfs file for each
host in /sys/class/scsi_host called "link_power_management_policy".
This file can have 3 possible values:
Value Meaning
-------------------------------------------------------------------
min_power User wishes the link to conserve power as much as
possible, even at the cost of some performance
max_performance User wants priority to be on performance, not power
savings
medium_power User wants power savings, with less performance cost
than min_power (but less power savings as well).
Signed-off-by: Kristen Carlson Accardi <[email protected]>
Index: 2.6-git/drivers/ata/libata-scsi.c
===================================================================
--- 2.6-git.orig/drivers/ata/libata-scsi.c
+++ 2.6-git/drivers/ata/libata-scsi.c
@@ -2890,6 +2890,51 @@ void ata_scsi_simulate(struct ata_device
}
}
+int ata_scsi_set_link_pm_policy(struct Scsi_Host *shost,
+ enum scsi_host_link_pm policy)
+{
+ struct ata_port *ap = ata_shost_to_port(shost);
+ int rc = -EINVAL;
+ int i;
+
+ /*
+ * make sure no broken devices are on this port,
+ * and that all devices support interface power
+ * management
+ */
+ for (i = 0; i < ATA_MAX_DEVICES; i++) {
+ struct ata_device *dev = &ap->device[i];
+
+ /* only check drives which exist */
+ if (!ata_dev_enabled(dev))
+ continue;
+
+ /*
+ * do we need to handle the case where we've hotplugged
+ * a broken drive (since hotplug and ALPM are mutually
+ * exclusive) ?
+ *
+ * If so, if we detect a broken drive on a port with
+ * alpm already enabled, then we should reset the policy
+ * to off for the entire port.
+ */
+ if ((dev->horkage & ATA_HORKAGE_ALPM) ||
+ !(dev->flags & ATA_DFLAG_IPM)) {
+ ata_dev_printk(dev, KERN_ERR,
+ "Unable to set Link PM policy\n");
+ ap->pm_policy = SHOST_MAX_PERFORMANCE;
+ }
+ }
+
+ if (ap->ops->enable_pm)
+ rc = ap->ops->enable_pm(ap, policy);
+
+ if (!rc)
+ shost->shost_link_pm_policy = ap->pm_policy;
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ata_scsi_set_link_pm_policy);
+
int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
{
int i, rc;
@@ -2912,7 +2957,7 @@ int ata_scsi_add_hosts(struct ata_host *
shost->max_lun = 1;
shost->max_channel = 1;
shost->max_cmd_len = 16;
-
+ shost->shost_link_pm_policy = ap->pm_policy;
rc = scsi_add_host(ap->scsi_host, ap->host->dev);
if (rc)
goto err_add;
Index: 2.6-git/drivers/scsi/hosts.c
===================================================================
--- 2.6-git.orig/drivers/scsi/hosts.c
+++ 2.6-git/drivers/scsi/hosts.c
@@ -54,6 +54,25 @@ static struct class shost_class = {
};
/**
+ * scsi_host_set_link_pm - Change the link power management policy
+ * @shost: scsi host to change the policy of.
+ * @policy: policy to change to.
+ *
+ * Returns zero if successful or an error if the requested
+ * transition is illegal.
+ **/
+int scsi_host_set_link_pm(struct Scsi_Host *shost,
+ enum scsi_host_link_pm policy)
+{
+ struct scsi_host_template *sht = shost->hostt;
+ if (sht->set_link_pm_policy)
+ sht->set_link_pm_policy(shost, policy);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(scsi_host_set_link_pm);
+
+/**
* scsi_host_set_state - Take the given host through the host
* state model.
* @shost: scsi host to change the state of.
Index: 2.6-git/drivers/scsi/scsi_sysfs.c
===================================================================
--- 2.6-git.orig/drivers/scsi/scsi_sysfs.c
+++ 2.6-git/drivers/scsi/scsi_sysfs.c
@@ -189,6 +189,74 @@ show_shost_state(struct class_device *cl
static CLASS_DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost_state);
+static const struct {
+ enum scsi_host_link_pm value;
+ char *name;
+} shost_link_pm_policy[] = {
+ { SHOST_NOT_AVAILABLE, "max_performance" },
+ { SHOST_MIN_POWER, "min_power" },
+ { SHOST_MAX_PERFORMANCE, "max_performance" },
+ { SHOST_MEDIUM_POWER, "medium_power" },
+};
+
+const char *scsi_host_link_pm_policy(enum scsi_host_link_pm policy)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < ARRAY_SIZE(shost_link_pm_policy); i++) {
+ if (shost_link_pm_policy[i].value == policy) {
+ name = shost_link_pm_policy[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
+static ssize_t store_link_pm_policy(struct class_device *class_dev,
+ const char *buf, size_t count)
+{
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ enum scsi_host_link_pm policy = 0;
+ int i;
+
+ /*
+ * we are skipping array location 0 on purpose - this
+ * is because a value of SHOST_NOT_AVAILABLE is displayed
+ * to the user as max_performance, but when the user
+ * writes "max_performance", they actually want the
+ * value to match SHOST_MAX_PERFORMANCE.
+ */
+ for (i = 1; i < ARRAY_SIZE(shost_link_pm_policy); i++) {
+ const int len = strlen(shost_link_pm_policy[i].name);
+ if (strncmp(shost_link_pm_policy[i].name, buf, len) == 0 &&
+ buf[len] == '\n') {
+ policy = shost_link_pm_policy[i].value;
+ break;
+ }
+ }
+ if (!policy)
+ return -EINVAL;
+
+ if (scsi_host_set_link_pm(shost, policy))
+ return -EINVAL;
+ return count;
+}
+static ssize_t
+show_link_pm_policy(struct class_device *class_dev, char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ const char *policy =
+ scsi_host_link_pm_policy(shost->shost_link_pm_policy);
+
+ if (!policy)
+ return -EINVAL;
+
+ return snprintf(buf, 23, "%s\n", policy);
+}
+static CLASS_DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
+ show_link_pm_policy, store_link_pm_policy);
+
shost_rd_attr(unique_id, "%u\n");
shost_rd_attr(host_busy, "%hu\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
@@ -207,6 +275,7 @@ static struct class_device_attribute *sc
&class_device_attr_proc_name,
&class_device_attr_scan,
&class_device_attr_state,
+ &class_device_attr_link_power_management_policy,
NULL
};
Index: 2.6-git/include/scsi/scsi_host.h
===================================================================
--- 2.6-git.orig/include/scsi/scsi_host.h
+++ 2.6-git/include/scsi/scsi_host.h
@@ -42,6 +42,16 @@ enum scsi_eh_timer_return {
EH_RESET_TIMER,
};
+/*
+ * shost pm policy: If you alter this, you also need to alter scsi_sysfs.c
+ * (for the ascii descriptions)
+ */
+enum scsi_host_link_pm {
+ SHOST_NOT_AVAILABLE,
+ SHOST_MIN_POWER,
+ SHOST_MAX_PERFORMANCE,
+ SHOST_MEDIUM_POWER,
+};
struct scsi_host_template {
struct module *module;
@@ -345,6 +355,12 @@ struct scsi_host_template {
int (*suspend)(struct scsi_device *, pm_message_t state);
/*
+ * link power management support
+ */
+ int (*set_link_pm_policy)(struct Scsi_Host *, enum scsi_host_link_pm);
+ enum scsi_host_link_pm default_link_pm_policy;
+
+ /*
* Name of proc directory
*/
char *proc_name;
@@ -642,6 +658,7 @@ struct Scsi_Host {
enum scsi_host_state shost_state;
+ enum scsi_host_link_pm shost_link_pm_policy;
/* ldm bits */
struct device shost_gendev;
@@ -749,4 +766,5 @@ extern struct Scsi_Host *scsi_register(s
extern void scsi_unregister(struct Scsi_Host *);
extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
+extern int scsi_host_set_link_pm(struct Scsi_Host *, enum scsi_host_link_pm);
#endif /* _SCSI_SCSI_HOST_H */
Index: 2.6-git/include/linux/libata.h
===================================================================
--- 2.6-git.orig/include/linux/libata.h
+++ 2.6-git/include/linux/libata.h
@@ -136,6 +136,7 @@ enum {
ATA_DFLAG_CDB_INTR = (1 << 2), /* device asserts INTRQ when ready for CDB */
ATA_DFLAG_NCQ = (1 << 3), /* device supports NCQ */
ATA_DFLAG_FLUSH_EXT = (1 << 4), /* do FLUSH_EXT instead of FLUSH */
+ ATA_DFLAG_IPM = (1 << 6), /* device supports interface PM */
ATA_DFLAG_CFG_MASK = (1 << 8) - 1,
ATA_DFLAG_PIO = (1 << 8), /* device limited to PIO mode */
@@ -299,6 +300,7 @@ enum {
ATA_HORKAGE_NONCQ = (1 << 2), /* Don't use NCQ */
ATA_HORKAGE_MAX_SEC_128 = (1 << 3), /* Limit max sects to 128 */
ATA_HORKAGE_DMA_RW_ONLY = (1 << 4), /* ATAPI DMA for RW only */
+ ATA_HORKAGE_ALPM = (1 << 5), /* ALPM problems */
};
enum hsm_task_states {
@@ -547,6 +549,7 @@ struct ata_port {
pm_message_t pm_mesg;
int *pm_result;
+ enum scsi_host_link_pm pm_policy;
void *private_data;
@@ -606,7 +609,7 @@ struct ata_port_operations {
int (*port_suspend) (struct ata_port *ap, pm_message_t mesg);
int (*port_resume) (struct ata_port *ap);
-
+ int (*enable_pm) (struct ata_port *ap, enum scsi_host_link_pm policy);
int (*port_start) (struct ata_port *ap);
void (*port_stop) (struct ata_port *ap);
@@ -811,7 +814,7 @@ extern int ata_cable_40wire(struct ata_p
extern int ata_cable_80wire(struct ata_port *ap);
extern int ata_cable_sata(struct ata_port *ap);
extern int ata_cable_unknown(struct ata_port *ap);
-
+extern int ata_scsi_set_link_pm_policy(struct Scsi_Host *shost, enum scsi_host_link_pm);
/*
* Timing helpers
*/
Index: 2.6-git/drivers/ata/libata-core.c
===================================================================
--- 2.6-git.orig/drivers/ata/libata-core.c
+++ 2.6-git/drivers/ata/libata-core.c
@@ -2019,6 +2019,9 @@ int ata_dev_configure(struct ata_device
if (dev->flags & ATA_DFLAG_LBA48)
dev->max_sectors = ATA_MAX_SECTORS_LBA48;
+ if (ata_id_has_hipm(dev->id))
+ dev->flags |= ATA_DFLAG_IPM;
+
if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
/* Let the user know. We don't want to disallow opens for
rescue purposes, or in case the vendor is just a blithering
@@ -2048,6 +2051,13 @@ int ata_dev_configure(struct ata_device
if (ata_device_blacklisted(dev) & ATA_HORKAGE_DMA_RW_ONLY)
dev->horkage |= ATA_HORKAGE_DMA_RW_ONLY;
+ if (ata_device_blacklisted(dev) & ATA_HORKAGE_ALPM) {
+ dev->horkage |= ATA_HORKAGE_ALPM;
+
+ /* reset link pm_policy for this port to no pm */
+ ap->pm_policy = SHOST_MAX_PERFORMANCE;
+ }
+
if (ap->ops->dev_config)
ap->ops->dev_config(dev);
@@ -6389,6 +6399,8 @@ int ata_host_register(struct ata_host *h
struct ata_port *ap = host->ports[i];
ata_scsi_scan_host(ap);
+ ata_scsi_set_link_pm_policy(ap->scsi_host,
+ ap->pm_policy);
}
return 0;
Index: 2.6-git/Documentation/scsi/link_power_management_policy.txt
===================================================================
--- /dev/null
+++ 2.6-git/Documentation/scsi/link_power_management_policy.txt
@@ -0,0 +1,19 @@
+This parameter allows the user to set the link (interface) power management.
+There are 3 possible options:
+
+Value Effect
+----------------------------------------------------------------------------
+min_power Tell the controller to try to make the link use the
+ least possible power when possible. This may
+ sacrifice some performance due to increased latency
+ when coming out of lower power states.
+
+max_performance Generally, this means no power management. Tell
+ the controller to have performance be a priority
+ over power management.
+
+medium_power Tell the controller to enter a lower power state
+ when possible, but do not enter the lowest power
+ state, thus improving latency over min_power setting.
+
+
Index: 2.6-git/include/linux/ata.h
===================================================================
--- 2.6-git.orig/include/linux/ata.h
+++ 2.6-git/include/linux/ata.h
@@ -320,6 +320,8 @@ struct ata_taskfile {
((u64) (id)[(n) + 0]) )
#define ata_id_cdb_intr(id) (((id)[0] & 0x60) == 0x20)
+#define ata_id_has_hipm(id) ((id)[76] & (1 << 9))
+#define ata_id_has_dipm(id) ((id)[78] & (1 << 3))
static inline unsigned int ata_id_major_version(const u16 *id)
{
--
Kristen Carlson Accardi wrote:
> This patch will modify the scsi and ata subsystem to allow
> users to set a power management policy for the link.
> libata drivers can define a function (enable_pm) that will
> perform hardware specific actions to enable whatever power
> management policy the user sets up if the driver supports
> it. This power management policy will be activated after
> all disks have been enumerated and intialized.
>
> The scsi subsystem will create a new sysfs file for each
> host in /sys/class/scsi_host called "link_power_management_policy".
> This file can have 3 possible values:
>
> Value Meaning
> -------------------------------------------------------------------
> min_power User wishes the link to conserve power as much as
> possible, even at the cost of some performance
>
> max_performance User wants priority to be on performance, not power
> savings
>
> medium_power User wants power savings, with less performance cost
> than min_power (but less power savings as well).
>
>
> Signed-off-by: Kristen Carlson Accardi <[email protected]>
seems OK at first glance, though I request that ata and scsi portions be
split into separate patches
Expose Power Management Policy option to users
This patch will modify the scsi subsystem to allow
users to set a power management policy for the link.
The scsi subsystem will create a new sysfs file for each
host in /sys/class/scsi_host called "link_power_management_policy".
This file can have 3 possible values:
Value Meaning
-------------------------------------------------------------------
min_power User wishes the link to conserve power as much as
possible, even at the cost of some performance
max_performance User wants priority to be on performance, not power
savings
medium_power User wants power savings, with less performance cost
than min_power (but less power savings as well).
Signed-off-by: Kristen Carlson Accardi <[email protected]>
Index: 2.6-git/drivers/scsi/hosts.c
===================================================================
--- 2.6-git.orig/drivers/scsi/hosts.c
+++ 2.6-git/drivers/scsi/hosts.c
@@ -54,6 +54,25 @@ static struct class shost_class = {
};
/**
+ * scsi_host_set_link_pm - Change the link power management policy
+ * @shost: scsi host to change the policy of.
+ * @policy: policy to change to.
+ *
+ * Returns zero if successful or an error if the requested
+ * transition is illegal.
+ **/
+int scsi_host_set_link_pm(struct Scsi_Host *shost,
+ enum scsi_host_link_pm policy)
+{
+ struct scsi_host_template *sht = shost->hostt;
+ if (sht->set_link_pm_policy)
+ sht->set_link_pm_policy(shost, policy);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(scsi_host_set_link_pm);
+
+/**
* scsi_host_set_state - Take the given host through the host
* state model.
* @shost: scsi host to change the state of.
Index: 2.6-git/drivers/scsi/scsi_sysfs.c
===================================================================
--- 2.6-git.orig/drivers/scsi/scsi_sysfs.c
+++ 2.6-git/drivers/scsi/scsi_sysfs.c
@@ -189,6 +189,74 @@ show_shost_state(struct class_device *cl
static CLASS_DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost_state);
+static const struct {
+ enum scsi_host_link_pm value;
+ char *name;
+} shost_link_pm_policy[] = {
+ { SHOST_NOT_AVAILABLE, "max_performance" },
+ { SHOST_MIN_POWER, "min_power" },
+ { SHOST_MAX_PERFORMANCE, "max_performance" },
+ { SHOST_MEDIUM_POWER, "medium_power" },
+};
+
+const char *scsi_host_link_pm_policy(enum scsi_host_link_pm policy)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < ARRAY_SIZE(shost_link_pm_policy); i++) {
+ if (shost_link_pm_policy[i].value == policy) {
+ name = shost_link_pm_policy[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
+static ssize_t store_link_pm_policy(struct class_device *class_dev,
+ const char *buf, size_t count)
+{
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ enum scsi_host_link_pm policy = 0;
+ int i;
+
+ /*
+ * we are skipping array location 0 on purpose - this
+ * is because a value of SHOST_NOT_AVAILABLE is displayed
+ * to the user as max_performance, but when the user
+ * writes "max_performance", they actually want the
+ * value to match SHOST_MAX_PERFORMANCE.
+ */
+ for (i = 1; i < ARRAY_SIZE(shost_link_pm_policy); i++) {
+ const int len = strlen(shost_link_pm_policy[i].name);
+ if (strncmp(shost_link_pm_policy[i].name, buf, len) == 0 &&
+ buf[len] == '\n') {
+ policy = shost_link_pm_policy[i].value;
+ break;
+ }
+ }
+ if (!policy)
+ return -EINVAL;
+
+ if (scsi_host_set_link_pm(shost, policy))
+ return -EINVAL;
+ return count;
+}
+static ssize_t
+show_link_pm_policy(struct class_device *class_dev, char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ const char *policy =
+ scsi_host_link_pm_policy(shost->shost_link_pm_policy);
+
+ if (!policy)
+ return -EINVAL;
+
+ return snprintf(buf, 23, "%s\n", policy);
+}
+static CLASS_DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
+ show_link_pm_policy, store_link_pm_policy);
+
shost_rd_attr(unique_id, "%u\n");
shost_rd_attr(host_busy, "%hu\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
@@ -207,6 +275,7 @@ static struct class_device_attribute *sc
&class_device_attr_proc_name,
&class_device_attr_scan,
&class_device_attr_state,
+ &class_device_attr_link_power_management_policy,
NULL
};
Index: 2.6-git/include/scsi/scsi_host.h
===================================================================
--- 2.6-git.orig/include/scsi/scsi_host.h
+++ 2.6-git/include/scsi/scsi_host.h
@@ -42,6 +42,16 @@ enum scsi_eh_timer_return {
EH_RESET_TIMER,
};
+/*
+ * shost pm policy: If you alter this, you also need to alter scsi_sysfs.c
+ * (for the ascii descriptions)
+ */
+enum scsi_host_link_pm {
+ SHOST_NOT_AVAILABLE,
+ SHOST_MIN_POWER,
+ SHOST_MAX_PERFORMANCE,
+ SHOST_MEDIUM_POWER,
+};
struct scsi_host_template {
struct module *module;
@@ -345,6 +355,12 @@ struct scsi_host_template {
int (*suspend)(struct scsi_device *, pm_message_t state);
/*
+ * link power management support
+ */
+ int (*set_link_pm_policy)(struct Scsi_Host *, enum scsi_host_link_pm);
+ enum scsi_host_link_pm default_link_pm_policy;
+
+ /*
* Name of proc directory
*/
char *proc_name;
@@ -642,6 +658,7 @@ struct Scsi_Host {
enum scsi_host_state shost_state;
+ enum scsi_host_link_pm shost_link_pm_policy;
/* ldm bits */
struct device shost_gendev;
@@ -749,4 +766,5 @@ extern struct Scsi_Host *scsi_register(s
extern void scsi_unregister(struct Scsi_Host *);
extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
+extern int scsi_host_set_link_pm(struct Scsi_Host *, enum scsi_host_link_pm);
#endif /* _SCSI_SCSI_HOST_H */
Index: 2.6-git/Documentation/scsi/link_power_management_policy.txt
===================================================================
--- /dev/null
+++ 2.6-git/Documentation/scsi/link_power_management_policy.txt
@@ -0,0 +1,19 @@
+This parameter allows the user to set the link (interface) power management.
+There are 3 possible options:
+
+Value Effect
+----------------------------------------------------------------------------
+min_power Tell the controller to try to make the link use the
+ least possible power when possible. This may
+ sacrifice some performance due to increased latency
+ when coming out of lower power states.
+
+max_performance Generally, this means no power management. Tell
+ the controller to have performance be a priority
+ over power management.
+
+medium_power Tell the controller to enter a lower power state
+ when possible, but do not enter the lowest power
+ state, thus improving latency over min_power setting.
+
+
Enable link power management for ata drivers
libata drivers can define a function (enable_pm) that will
perform hardware specific actions to enable whatever power
management policy the user set up from the scsi sysfs
interface if the driver supports it. This power management
policy will be activated after all disks have been
enumerated and intialized.
Signed-off-by: Kristen Carlson Accardi <[email protected]>
Index: 2.6-git/drivers/ata/libata-scsi.c
===================================================================
--- 2.6-git.orig/drivers/ata/libata-scsi.c
+++ 2.6-git/drivers/ata/libata-scsi.c
@@ -2890,6 +2890,51 @@ void ata_scsi_simulate(struct ata_device
}
}
+int ata_scsi_set_link_pm_policy(struct Scsi_Host *shost,
+ enum scsi_host_link_pm policy)
+{
+ struct ata_port *ap = ata_shost_to_port(shost);
+ int rc = -EINVAL;
+ int i;
+
+ /*
+ * make sure no broken devices are on this port,
+ * and that all devices support interface power
+ * management
+ */
+ for (i = 0; i < ATA_MAX_DEVICES; i++) {
+ struct ata_device *dev = &ap->device[i];
+
+ /* only check drives which exist */
+ if (!ata_dev_enabled(dev))
+ continue;
+
+ /*
+ * do we need to handle the case where we've hotplugged
+ * a broken drive (since hotplug and ALPM are mutually
+ * exclusive) ?
+ *
+ * If so, if we detect a broken drive on a port with
+ * alpm already enabled, then we should reset the policy
+ * to off for the entire port.
+ */
+ if ((dev->horkage & ATA_HORKAGE_ALPM) ||
+ !(dev->flags & ATA_DFLAG_IPM)) {
+ ata_dev_printk(dev, KERN_ERR,
+ "Unable to set Link PM policy\n");
+ ap->pm_policy = SHOST_MAX_PERFORMANCE;
+ }
+ }
+
+ if (ap->ops->enable_pm)
+ rc = ap->ops->enable_pm(ap, policy);
+
+ if (!rc)
+ shost->shost_link_pm_policy = ap->pm_policy;
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ata_scsi_set_link_pm_policy);
+
int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
{
int i, rc;
@@ -2912,7 +2957,7 @@ int ata_scsi_add_hosts(struct ata_host *
shost->max_lun = 1;
shost->max_channel = 1;
shost->max_cmd_len = 16;
-
+ shost->shost_link_pm_policy = ap->pm_policy;
rc = scsi_add_host(ap->scsi_host, ap->host->dev);
if (rc)
goto err_add;
Index: 2.6-git/include/linux/libata.h
===================================================================
--- 2.6-git.orig/include/linux/libata.h
+++ 2.6-git/include/linux/libata.h
@@ -136,6 +136,7 @@ enum {
ATA_DFLAG_CDB_INTR = (1 << 2), /* device asserts INTRQ when ready for CDB */
ATA_DFLAG_NCQ = (1 << 3), /* device supports NCQ */
ATA_DFLAG_FLUSH_EXT = (1 << 4), /* do FLUSH_EXT instead of FLUSH */
+ ATA_DFLAG_IPM = (1 << 6), /* device supports interface PM */
ATA_DFLAG_CFG_MASK = (1 << 8) - 1,
ATA_DFLAG_PIO = (1 << 8), /* device limited to PIO mode */
@@ -300,6 +301,7 @@ enum {
ATA_HORKAGE_NONCQ = (1 << 2), /* Don't use NCQ */
ATA_HORKAGE_MAX_SEC_128 = (1 << 3), /* Limit max sects to 128 */
ATA_HORKAGE_DMA_RW_ONLY = (1 << 4), /* ATAPI DMA for RW only */
+ ATA_HORKAGE_ALPM = (1 << 5), /* ALPM problems */
};
enum hsm_task_states {
@@ -548,6 +550,7 @@ struct ata_port {
pm_message_t pm_mesg;
int *pm_result;
+ enum scsi_host_link_pm pm_policy;
void *private_data;
@@ -607,7 +610,7 @@ struct ata_port_operations {
int (*port_suspend) (struct ata_port *ap, pm_message_t mesg);
int (*port_resume) (struct ata_port *ap);
-
+ int (*enable_pm) (struct ata_port *ap, enum scsi_host_link_pm policy);
int (*port_start) (struct ata_port *ap);
void (*port_stop) (struct ata_port *ap);
@@ -812,7 +815,7 @@ extern int ata_cable_40wire(struct ata_p
extern int ata_cable_80wire(struct ata_port *ap);
extern int ata_cable_sata(struct ata_port *ap);
extern int ata_cable_unknown(struct ata_port *ap);
-
+extern int ata_scsi_set_link_pm_policy(struct Scsi_Host *shost, enum scsi_host_link_pm);
/*
* Timing helpers
*/
Index: 2.6-git/drivers/ata/libata-core.c
===================================================================
--- 2.6-git.orig/drivers/ata/libata-core.c
+++ 2.6-git/drivers/ata/libata-core.c
@@ -2019,6 +2019,9 @@ int ata_dev_configure(struct ata_device
if (dev->flags & ATA_DFLAG_LBA48)
dev->max_sectors = ATA_MAX_SECTORS_LBA48;
+ if (ata_id_has_hipm(dev->id))
+ dev->flags |= ATA_DFLAG_IPM;
+
if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
/* Let the user know. We don't want to disallow opens for
rescue purposes, or in case the vendor is just a blithering
@@ -2048,6 +2051,13 @@ int ata_dev_configure(struct ata_device
if (ata_device_blacklisted(dev) & ATA_HORKAGE_DMA_RW_ONLY)
dev->horkage |= ATA_HORKAGE_DMA_RW_ONLY;
+ if (ata_device_blacklisted(dev) & ATA_HORKAGE_ALPM) {
+ dev->horkage |= ATA_HORKAGE_ALPM;
+
+ /* reset link pm_policy for this port to no pm */
+ ap->pm_policy = SHOST_MAX_PERFORMANCE;
+ }
+
if (ap->ops->dev_config)
ap->ops->dev_config(dev);
@@ -6394,6 +6404,8 @@ int ata_host_register(struct ata_host *h
struct ata_port *ap = host->ports[i];
ata_scsi_scan_host(ap);
+ ata_scsi_set_link_pm_policy(ap->scsi_host,
+ ap->pm_policy);
}
return 0;
Index: 2.6-git/include/linux/ata.h
===================================================================
--- 2.6-git.orig/include/linux/ata.h
+++ 2.6-git/include/linux/ata.h
@@ -320,6 +320,8 @@ struct ata_taskfile {
((u64) (id)[(n) + 0]) )
#define ata_id_cdb_intr(id) (((id)[0] & 0x60) == 0x20)
+#define ata_id_has_hipm(id) ((id)[76] & (1 << 9))
+#define ata_id_has_dipm(id) ((id)[78] & (1 << 3))
static inline unsigned int ata_id_major_version(const u16 *id)
{
On Tue, 2007-06-12 at 10:46 -0700, Kristen Carlson Accardi wrote:
> Expose Power Management Policy option to users
>
> This patch will modify the scsi subsystem to allow
> users to set a power management policy for the link.
>
> The scsi subsystem will create a new sysfs file for each
> host in /sys/class/scsi_host called "link_power_management_policy".
> This file can have 3 possible values:
I'm afraid the host isn't really the right place to put the link power
management policy (assuming you want to manage the individual links
separately) because there isn't a one to one correspondence between
links and hosts.
To take the model I understand: SAS; the links are managed at the phy
level, so the power policy should be set there and thus should probably
be a property of the phy object, which doesn't even exist in the SCSI
model, it only exists in the transport class. It strikes me that even
for ATA, the same thing is probably true.
Now, I can see that the power management models of all the transports
might share some similarities (particularly at this three stage granular
level); if so, it might make sense to export helpers from the mid-layer
for the transport classes to use for this.
> Value Meaning
> -------------------------------------------------------------------
> min_power User wishes the link to conserve power as much as
> possible, even at the cost of some performance
>
> max_performance User wants priority to be on performance, not power
> savings
>
> medium_power User wants power savings, with less performance cost
> than min_power (but less power savings as well).
These seem like nicely sane and generic values.
James
James Bottomley wrote:
> To take the model I understand: SAS; the links are managed at the phy
> level, so the power policy should be set there and thus should probably
> be a property of the phy object, which doesn't even exist in the SCSI
> model, it only exists in the transport class. It strikes me that even
> for ATA, the same thing is probably true.
>
> Now, I can see that the power management models of all the transports
> might share some similarities (particularly at this three stage granular
> level); if so, it might make sense to export helpers from the mid-layer
> for the transport classes to use for this.
Agreed, in principle.
Jeff
On Wed, 13 Jun 2007 08:26:48 -0700
James Bottomley <[email protected]> wrote:
> On Tue, 2007-06-12 at 10:46 -0700, Kristen Carlson Accardi wrote:
> > Expose Power Management Policy option to users
> >
> > This patch will modify the scsi subsystem to allow
> > users to set a power management policy for the link.
> >
> > The scsi subsystem will create a new sysfs file for each
> > host in /sys/class/scsi_host called "link_power_management_policy".
> > This file can have 3 possible values:
>
> I'm afraid the host isn't really the right place to put the link power
> management policy (assuming you want to manage the individual links
> separately) because there isn't a one to one correspondence between
> links and hosts.
>
> To take the model I understand: SAS; the links are managed at the phy
> level, so the power policy should be set there and thus should probably
> be a property of the phy object, which doesn't even exist in the SCSI
> model, it only exists in the transport class. It strikes me that even
> for ATA, the same thing is probably true.
>
> Now, I can see that the power management models of all the transports
> might share some similarities (particularly at this three stage granular
> level); if so, it might make sense to export helpers from the mid-layer
> for the transport classes to use for this.
Ok - sorry for my ignorance about SCSI - but my sources (i.e. Arjan) tell
me that the problem is that Link in ATA land means something different than
Link in SCSI land, and that what I really need to do is leave this code under
the Host class, but rename it to something that more accurately reflects
what it means under SCSI. So, is the word "segment" more appropriate?
Should I rename the file to "segment_power_management_policy"?
Thanks,
kristen
>
> > Value Meaning
> > -------------------------------------------------------------------
> > min_power User wishes the link to conserve power as much as
> > possible, even at the cost of some performance
> >
> > max_performance User wants priority to be on performance, not power
> > savings
> >
> > medium_power User wants power savings, with less performance cost
> > than min_power (but less power savings as well).
>
> These seem like nicely sane and generic values.
>
> James
>
Kristen Carlson Accardi wrote:
> Ok - sorry for my ignorance about SCSI - but my sources (i.e. Arjan) tell
> me that the problem is that Link in ATA land means something different than
> Link in SCSI land, and that what I really need to do is leave this code under
> the Host class, but rename it to something that more accurately reflects
> what it means under SCSI.
James' analogy holds, and is even more true once SATA Port Multipliers
are in the picture. Then you have remote SATA phys. And James has
essentially stated a long term libata problem: libata wants its own ATA
transport class, and perhaps a cleaning-up and coalescing of the
in-kernel SATA phy objects and processes.
The main difference is that SATA doesn't have to worry about target phys
and initiator phys, largely just the initiator phy. And phys in SATA
don't have unique identifiers (WWNs).
I don't think we should delay ALPM in order to complete phy objects and
an ATA transport class. But OTOH a transport class may be the best
place to put these new sysfs nodes. But#2, that train of logic leads
one down the road of implementing a minimal ATA transport class across
all supported ATA devices, which is something that probably only James
is an expert at (transport classes that is, not ATA).
> Should I rename the file to "segment_power_management_policy"?
No.
Jeff
Enable link power management for ata drivers
libata drivers can define a function (enable_pm) that will
perform hardware specific actions to enable whatever power
management policy the user set up from the scsi sysfs
interface if the driver supports it. This power management
policy will be activated after all disks have been
enumerated and initialized. Drivers should also define
disable_pm, which will turn off link power management, but
not change link power management policy.
Signed-off-by: Kristen Carlson Accardi <[email protected]>
---
I've updated this patch to fix a problem with suspend breaking when
alpm is enabled. To fix this, I've changed the patch to allow drivers
to have a disable_pm function which can be used by the host controller
to turn off link power managment before requesting an PM activity.
We will turn it back on after Resume.
This whole series can be found at:
http://www.kernel.org/pub/linux/kernel/people/kristen/patches/SATA/alpm/
Index: 2.6-git/drivers/ata/libata-scsi.c
===================================================================
--- 2.6-git.orig/drivers/ata/libata-scsi.c
+++ 2.6-git/drivers/ata/libata-scsi.c
@@ -2909,6 +2909,51 @@ void ata_scsi_simulate(struct ata_device
}
}
+int ata_scsi_set_link_pm_policy(struct Scsi_Host *shost,
+ enum scsi_host_link_pm policy)
+{
+ struct ata_port *ap = ata_shost_to_port(shost);
+ int rc = -EINVAL;
+ int i;
+
+ /*
+ * make sure no broken devices are on this port,
+ * and that all devices support interface power
+ * management
+ */
+ for (i = 0; i < ATA_MAX_DEVICES; i++) {
+ struct ata_device *dev = &ap->device[i];
+
+ /* only check drives which exist */
+ if (!ata_dev_enabled(dev))
+ continue;
+
+ /*
+ * do we need to handle the case where we've hotplugged
+ * a broken drive (since hotplug and ALPM are mutually
+ * exclusive) ?
+ *
+ * If so, if we detect a broken drive on a port with
+ * alpm already enabled, then we should reset the policy
+ * to off for the entire port.
+ */
+ if ((dev->horkage & ATA_HORKAGE_ALPM) ||
+ !(dev->flags & ATA_DFLAG_IPM)) {
+ ata_dev_printk(dev, KERN_ERR,
+ "Unable to set Link PM policy\n");
+ ap->pm_policy = SHOST_MAX_PERFORMANCE;
+ }
+ }
+
+ if (ap->ops->enable_pm)
+ rc = ap->ops->enable_pm(ap, policy);
+
+ if (!rc)
+ shost->shost_link_pm_policy = ap->pm_policy;
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ata_scsi_set_link_pm_policy);
+
int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
{
int i, rc;
@@ -2931,7 +2976,7 @@ int ata_scsi_add_hosts(struct ata_host *
shost->max_lun = 1;
shost->max_channel = 1;
shost->max_cmd_len = 16;
-
+ shost->shost_link_pm_policy = ap->pm_policy;
rc = scsi_add_host(ap->scsi_host, ap->host->dev);
if (rc)
goto err_add;
Index: 2.6-git/include/linux/libata.h
===================================================================
--- 2.6-git.orig/include/linux/libata.h
+++ 2.6-git/include/linux/libata.h
@@ -136,6 +136,7 @@ enum {
ATA_DFLAG_CDB_INTR = (1 << 2), /* device asserts INTRQ when ready for CDB */
ATA_DFLAG_NCQ = (1 << 3), /* device supports NCQ */
ATA_DFLAG_FLUSH_EXT = (1 << 4), /* do FLUSH_EXT instead of FLUSH */
+ ATA_DFLAG_IPM = (1 << 6), /* device supports interface PM */
ATA_DFLAG_CFG_MASK = (1 << 8) - 1,
ATA_DFLAG_PIO = (1 << 8), /* device limited to PIO mode */
@@ -299,6 +300,7 @@ enum {
ATA_HORKAGE_NONCQ = (1 << 2), /* Don't use NCQ */
ATA_HORKAGE_MAX_SEC_128 = (1 << 3), /* Limit max sects to 128 */
ATA_HORKAGE_DMA_RW_ONLY = (1 << 4), /* ATAPI DMA for RW only */
+ ATA_HORKAGE_ALPM = (1 << 5), /* ALPM problems */
};
enum hsm_task_states {
@@ -547,6 +549,7 @@ struct ata_port {
pm_message_t pm_mesg;
int *pm_result;
+ enum scsi_host_link_pm pm_policy;
void *private_data;
@@ -606,7 +609,8 @@ struct ata_port_operations {
int (*port_suspend) (struct ata_port *ap, pm_message_t mesg);
int (*port_resume) (struct ata_port *ap);
-
+ int (*enable_pm) (struct ata_port *ap, enum scsi_host_link_pm policy);
+ int (*disable_pm) (struct ata_port *ap);
int (*port_start) (struct ata_port *ap);
void (*port_stop) (struct ata_port *ap);
@@ -812,7 +816,7 @@ extern int ata_cable_40wire(struct ata_p
extern int ata_cable_80wire(struct ata_port *ap);
extern int ata_cable_sata(struct ata_port *ap);
extern int ata_cable_unknown(struct ata_port *ap);
-
+extern int ata_scsi_set_link_pm_policy(struct Scsi_Host *shost, enum scsi_host_link_pm);
/*
* Timing helpers
*/
Index: 2.6-git/drivers/ata/libata-core.c
===================================================================
--- 2.6-git.orig/drivers/ata/libata-core.c
+++ 2.6-git/drivers/ata/libata-core.c
@@ -2021,6 +2021,9 @@ int ata_dev_configure(struct ata_device
if (dev->flags & ATA_DFLAG_LBA48)
dev->max_sectors = ATA_MAX_SECTORS_LBA48;
+ if (ata_id_has_hipm(dev->id))
+ dev->flags |= ATA_DFLAG_IPM;
+
if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
/* Let the user know. We don't want to disallow opens for
rescue purposes, or in case the vendor is just a blithering
@@ -2050,6 +2053,13 @@ int ata_dev_configure(struct ata_device
if (ata_device_blacklisted(dev) & ATA_HORKAGE_DMA_RW_ONLY)
dev->horkage |= ATA_HORKAGE_DMA_RW_ONLY;
+ if (ata_device_blacklisted(dev) & ATA_HORKAGE_ALPM) {
+ dev->horkage |= ATA_HORKAGE_ALPM;
+
+ /* reset link pm_policy for this port to no pm */
+ ap->pm_policy = SHOST_MAX_PERFORMANCE;
+ }
+
if (ap->ops->dev_config)
ap->ops->dev_config(dev);
@@ -5823,6 +5833,28 @@ int ata_flush_cache(struct ata_device *d
return 0;
}
+static void ata_host_disable_link_pm(struct ata_host *host)
+{
+ int i;
+
+ for (i = 0; i < host->n_ports; i++) {
+ struct ata_port *ap = host->ports[i];
+ if (ap->ops->disable_pm)
+ ap->ops->disable_pm(ap);
+ }
+}
+
+static void ata_host_enable_link_pm(struct ata_host *host)
+{
+ int i;
+
+ for (i = 0; i < host->n_ports; i++) {
+ struct ata_port *ap = host->ports[i];
+ ata_scsi_set_link_pm_policy(ap->scsi_host,
+ ap->pm_policy);
+ }
+}
+
#ifdef CONFIG_PM
static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
unsigned int action, unsigned int ehi_flags,
@@ -5890,6 +5922,12 @@ int ata_host_suspend(struct ata_host *ho
{
int rc;
+ /*
+ * disable link pm on all ports before requesting
+ * any pm activity
+ */
+ ata_host_disable_link_pm(host);
+
rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
if (rc == 0)
host->dev->power.power_state = mesg;
@@ -5912,6 +5950,9 @@ void ata_host_resume(struct ata_host *ho
ata_host_request_pm(host, PMSG_ON, ATA_EH_SOFTRESET,
ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 0);
host->dev->power.power_state = PMSG_ON;
+
+ /* reenable link pm */
+ ata_host_enable_link_pm(host);
}
#endif
@@ -6401,6 +6442,8 @@ int ata_host_register(struct ata_host *h
struct ata_port *ap = host->ports[i];
ata_scsi_scan_host(ap);
+ ata_scsi_set_link_pm_policy(ap->scsi_host,
+ ap->pm_policy);
}
return 0;
Index: 2.6-git/include/linux/ata.h
===================================================================
--- 2.6-git.orig/include/linux/ata.h
+++ 2.6-git/include/linux/ata.h
@@ -321,6 +321,8 @@ struct ata_taskfile {
((u64) (id)[(n) + 0]) )
#define ata_id_cdb_intr(id) (((id)[0] & 0x60) == 0x20)
+#define ata_id_has_hipm(id) ((id)[76] & (1 << 9))
+#define ata_id_has_dipm(id) ((id)[78] & (1 << 3))
static inline unsigned int ata_id_major_version(const u16 *id)
{