Commit acbf167d authored by Darrick J. Wong's avatar Darrick J. Wong Committed by James Bottomley
Browse files

[SCSI] libsas: Add a sysfs knob to enable/disable a phy 



This patch lets a user arbitrarily enable or disable a phy via sysfs.
Potential applications include shutting down a phy to replace one
lane of wide port, and (more importantly) providing a method for the
libata SATL to control the phy.

Signed-off-by: default avatarDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent b218a0d8

drivers/scsi/libsas/sas_init.c

+33 −2
Original line number Diff line number Diff line
@@ -146,6 +146,36 @@ static int sas_get_linkerrors(struct sas_phy *phy) 
	return sas_smp_get_phy_events(phy);

}



int sas_phy_enable(struct sas_phy *phy, int enable)

{

	int ret;

	enum phy_func command;



	if (enable)

		command = PHY_FUNC_LINK_RESET;

	else

		command = PHY_FUNC_DISABLE;



	if (scsi_is_sas_phy_local(phy)) {

		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);

		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);

		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];

		struct sas_internal *i =

			to_sas_internal(sas_ha->core.shost->transportt);



		if (!enable) {

			sas_phy_disconnected(asd_phy);

			sas_ha->notify_phy_event(asd_phy, PHYE_LOSS_OF_SIGNAL);

		}

		ret = i->dft->lldd_control_phy(asd_phy, command, NULL);

	} else {

		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);

		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);

		ret = sas_smp_phy_control(ddev, phy->number, command, NULL);

	}

	return ret;

}



int sas_phy_reset(struct sas_phy *phy, int hard_reset)

{

	int ret;
@@ -172,7 +202,7 @@ int sas_phy_reset(struct sas_phy *phy, int hard_reset) 
	return ret;

}



static int sas_set_phy_speed(struct sas_phy *phy,

int sas_set_phy_speed(struct sas_phy *phy,

		      struct sas_phy_linkrates *rates)

{

	int ret;
@@ -212,6 +242,7 @@ static int sas_set_phy_speed(struct sas_phy *phy, 
}



static struct sas_function_template sft = {

	.phy_enable = sas_phy_enable,

	.phy_reset = sas_phy_reset,

	.set_phy_speed = sas_set_phy_speed,

	.get_linkerrors = sas_get_linkerrors,

drivers/scsi/libsas/sas_scsi_host.c

+1 −0
Original line number Diff line number Diff line
@@ -875,3 +875,4 @@ EXPORT_SYMBOL_GPL(sas_change_queue_type); 
EXPORT_SYMBOL_GPL(sas_bios_param);

EXPORT_SYMBOL_GPL(sas_task_abort);

EXPORT_SYMBOL_GPL(sas_phy_reset);

EXPORT_SYMBOL_GPL(sas_phy_enable);

drivers/scsi/scsi_transport_sas.c

+51 −0
Original line number Diff line number Diff line
@@ -336,6 +336,51 @@ show_sas_device_type(struct class_device *cdev, char *buf) 
}

static CLASS_DEVICE_ATTR(device_type, S_IRUGO, show_sas_device_type, NULL);



static ssize_t do_sas_phy_enable(struct class_device *cdev,

		size_t count, int enable)

{

	struct sas_phy *phy = transport_class_to_phy(cdev);

	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);

	struct sas_internal *i = to_sas_internal(shost->transportt);

	int error;



	error = i->f->phy_enable(phy, enable);

	if (error)

		return error;

	phy->enabled = enable;

	return count;

};



static ssize_t store_sas_phy_enable(struct class_device *cdev,

		const char *buf, size_t count)

{

	if (count < 1)

		return -EINVAL;



	switch (buf[0]) {

	case '0':

		do_sas_phy_enable(cdev, count, 0);

		break;

	case '1':

		do_sas_phy_enable(cdev, count, 1);

		break;

	default:

		return -EINVAL;

	}



	return count;

}



static ssize_t show_sas_phy_enable(struct class_device *cdev, char *buf)

{

	struct sas_phy *phy = transport_class_to_phy(cdev);



	return snprintf(buf, 20, "%d", phy->enabled);

}



static CLASS_DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, show_sas_phy_enable,

			 store_sas_phy_enable);



static ssize_t do_sas_phy_reset(struct class_device *cdev,

		size_t count, int hard_reset)

{
@@ -435,6 +480,7 @@ struct sas_phy *sas_phy_alloc(struct device *parent, int number) 
		return NULL;



	phy->number = number;

	phy->enabled = 1;



	device_initialize(&phy->dev);

	phy->dev.parent = get_device(parent);
@@ -1389,6 +1435,10 @@ static int sas_user_scan(struct Scsi_Host *shost, uint channel, 
	SETUP_TEMPLATE_RW(phy_attrs, field, S_IRUGO | S_IWUSR, 1,	\

			!i->f->set_phy_speed, S_IRUGO)



#define SETUP_OPTIONAL_PHY_ATTRIBUTE_RW(field, func)			\

	SETUP_TEMPLATE_RW(phy_attrs, field, S_IRUGO | S_IWUSR, 1,	\

			  !i->f->func, S_IRUGO)



#define SETUP_PORT_ATTRIBUTE(field)					\

	SETUP_TEMPLATE(port_attrs, field, S_IRUGO, 1)
@@ -1479,6 +1529,7 @@ sas_attach_transport(struct sas_function_template *ft) 
	SETUP_PHY_ATTRIBUTE(phy_reset_problem_count);

	SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(link_reset, phy_reset);

	SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(hard_reset, phy_reset);

	SETUP_OPTIONAL_PHY_ATTRIBUTE_RW(enable, phy_enable);

	i->phy_attrs[count] = NULL;



	count = 0;

include/scsi/libsas.h

+3 −0
Original line number Diff line number Diff line
@@ -614,6 +614,9 @@ struct sas_domain_function_template { 
extern int sas_register_ha(struct sas_ha_struct *);

extern int sas_unregister_ha(struct sas_ha_struct *);



int sas_set_phy_speed(struct sas_phy *phy,

		      struct sas_phy_linkrates *rates);

int sas_phy_enable(struct sas_phy *phy, int enabled);

int sas_phy_reset(struct sas_phy *phy, int hard_reset);

extern int sas_queuecommand(struct scsi_cmnd *,

		     void (*scsi_done)(struct scsi_cmnd *));

include/scsi/scsi_transport_sas.h

+2 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ struct sas_identify { 
struct sas_phy {

	struct device		dev;

	int			number;

	int			enabled;



	/* phy identification */

	struct sas_identify	identify;
@@ -163,6 +164,7 @@ struct sas_function_template { 
	int (*get_enclosure_identifier)(struct sas_rphy *, u64 *);

	int (*get_bay_identifier)(struct sas_rphy *);

	int (*phy_reset)(struct sas_phy *, int);

	int (*phy_enable)(struct sas_phy *, int);

	int (*set_phy_speed)(struct sas_phy *, struct sas_phy_linkrates *);

};

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