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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: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
hifive-unleashed-5.1
Mika Westerberg 2016-02-18 10:54:16 +02:00 committed by Tejun Heo
parent f1d848f9fb
commit bb03c64069
1 changed files with 47 additions and 1 deletions
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48
drivers/ata/libahci.c
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@ -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