Commit bb03c640 authored by Mika Westerberg's avatar Mika Westerberg Committed by Tejun Heo
Browse files

ahci: Add functions to manage runtime PM of AHCI ports 



Add new functions ahci_rpm_get_port()/ahci_rpm_put_port() that change
runtime PM status of AHCI ports. Depending if the AHCI host has runtime PM
enabled or disabled calling these may trigger runtime suspend/resume of the
host controller.

We also call these functions in appropriate places to make sure host
controller registers are available before using them.

Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent f1d848f9

drivers/ata/libahci.c

+47 −1
Original line number Diff line number Diff line
@@ -225,6 +225,31 @@ static void ahci_enable_ahci(void __iomem *mmio) 
	WARN_ON(1);

}



/**

 *	ahci_rpm_get_port - Make sure the port is powered on

 *	@ap: Port to power on

 *

 *	Whenever there is need to access the AHCI host registers outside of

 *	normal execution paths, call this function to make sure the host is

 *	actually powered on.

 */

static int ahci_rpm_get_port(struct ata_port *ap)

{

	return pm_runtime_get_sync(ap->dev);

}



/**

 *	ahci_rpm_put_port - Undoes ahci_rpm_get_port()

 *	@ap: Port to power down

 *

 *	Undoes ahci_rpm_get_port() and possibly powers down the AHCI host

 *	if it has no more active users.

 */

static void ahci_rpm_put_port(struct ata_port *ap)

{

	pm_runtime_put(ap->dev);

}



static ssize_t ahci_show_host_caps(struct device *dev,

				   struct device_attribute *attr, char *buf)

{
@@ -261,8 +286,13 @@ static ssize_t ahci_show_port_cmd(struct device *dev, 
	struct Scsi_Host *shost = class_to_shost(dev);

	struct ata_port *ap = ata_shost_to_port(shost);

	void __iomem *port_mmio = ahci_port_base(ap);

	ssize_t ret;



	return sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));

	ahci_rpm_get_port(ap);

	ret = sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));

	ahci_rpm_put_port(ap);



	return ret;

}



static ssize_t ahci_read_em_buffer(struct device *dev,
@@ -278,17 +308,20 @@ static ssize_t ahci_read_em_buffer(struct device *dev, 
	size_t count;

	int i;



	ahci_rpm_get_port(ap);

	spin_lock_irqsave(ap->lock, flags);



	em_ctl = readl(mmio + HOST_EM_CTL);

	if (!(ap->flags & ATA_FLAG_EM) || em_ctl & EM_CTL_XMT ||

	    !(hpriv->em_msg_type & EM_MSG_TYPE_SGPIO)) {

		spin_unlock_irqrestore(ap->lock, flags);

		ahci_rpm_put_port(ap);

		return -EINVAL;

	}



	if (!(em_ctl & EM_CTL_MR)) {

		spin_unlock_irqrestore(ap->lock, flags);

		ahci_rpm_put_port(ap);

		return -EAGAIN;

	}
@@ -316,6 +349,7 @@ static ssize_t ahci_read_em_buffer(struct device *dev, 
	}



	spin_unlock_irqrestore(ap->lock, flags);

	ahci_rpm_put_port(ap);



	return i;

}
@@ -340,11 +374,13 @@ static ssize_t ahci_store_em_buffer(struct device *dev, 
	    size % 4 || size > hpriv->em_buf_sz)

		return -EINVAL;



	ahci_rpm_get_port(ap);

	spin_lock_irqsave(ap->lock, flags);



	em_ctl = readl(mmio + HOST_EM_CTL);

	if (em_ctl & EM_CTL_TM) {

		spin_unlock_irqrestore(ap->lock, flags);

		ahci_rpm_put_port(ap);

		return -EBUSY;

	}
@@ -357,6 +393,7 @@ static ssize_t ahci_store_em_buffer(struct device *dev, 
	writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);



	spin_unlock_irqrestore(ap->lock, flags);

	ahci_rpm_put_port(ap);



	return size;

}
@@ -370,7 +407,9 @@ static ssize_t ahci_show_em_supported(struct device *dev, 
	void __iomem *mmio = hpriv->mmio;

	u32 em_ctl;



	ahci_rpm_get_port(ap);

	em_ctl = readl(mmio + HOST_EM_CTL);

	ahci_rpm_put_port(ap);



	return sprintf(buf, "%s%s%s%s\n",

		       em_ctl & EM_CTL_LED ? "led " : "",
@@ -1014,6 +1053,7 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state, 
	else

		return -EINVAL;



	ahci_rpm_get_port(ap);

	spin_lock_irqsave(ap->lock, flags);



	/*
@@ -1023,6 +1063,7 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state, 
	em_ctl = readl(mmio + HOST_EM_CTL);

	if (em_ctl & EM_CTL_TM) {

		spin_unlock_irqrestore(ap->lock, flags);

		ahci_rpm_put_port(ap);

		return -EBUSY;

	}
@@ -1050,6 +1091,8 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state, 
	emp->led_state = state;



	spin_unlock_irqrestore(ap->lock, flags);

	ahci_rpm_put_port(ap);



	return size;

}
@@ -2216,6 +2259,8 @@ static void ahci_pmp_detach(struct ata_port *ap) 


int ahci_port_resume(struct ata_port *ap)

{

	ahci_rpm_get_port(ap);



	ahci_power_up(ap);

	ahci_start_port(ap);
@@ -2242,6 +2287,7 @@ static int ahci_port_suspend(struct ata_port *ap, pm_message_t mesg) 
		ata_port_freeze(ap);

	}



	ahci_rpm_put_port(ap);

	return rc;

}

#endif

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