The newly introduced ahci_platform_shutdown() method is called during system shutdown to disable host controller DMA and interrupts in order to avoid potentially corrupting or otherwise interfering with a new kernel being started with kexec.
Signed-off-by: Nate Watterson <[email protected]> --- drivers/ata/ahci_platform.c | 1 + drivers/ata/libahci_platform.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/ahci_platform.h | 2 ++ 3 files changed, 37 insertions(+) diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c index 62a04c8..99f9a89 100644 --- a/drivers/ata/ahci_platform.c +++ b/drivers/ata/ahci_platform.c @@ -93,6 +93,7 @@ static SIMPLE_DEV_PM_OPS(ahci_pm_ops, ahci_platform_suspend, static struct platform_driver ahci_driver = { .probe = ahci_probe, .remove = ata_platform_remove_one, + .shutdown = ahci_platform_shutdown, .driver = { .name = DRV_NAME, .of_match_table = ahci_of_match, diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c index cd2eab6..a270a11 100644 --- a/drivers/ata/libahci_platform.c +++ b/drivers/ata/libahci_platform.c @@ -602,6 +602,40 @@ static void ahci_host_stop(struct ata_host *host) ahci_platform_disable_resources(hpriv); } +/** + * ahci_platform_shutdown - Disable interrupts and stop DMA for host ports + * @dev: platform device pointer for the host + * + * This function is called during system shutdown and performs the minimal + * deconfiguration required to ensure that an ahci_platform host cannot + * corrupt or otherwise interfere with a new kernel being started with kexec. + */ +void ahci_platform_shutdown(struct platform_device *pdev) +{ + struct ata_host *host = platform_get_drvdata(pdev); + struct ahci_host_priv *hpriv = host->private_data; + void __iomem *mmio = hpriv->mmio; + int i; + + for (i = 0; i < host->n_ports; i++) { + struct ata_port *ap = host->ports[i]; + + /* Disable port interrupts */ + if (ap->ops->freeze) + ap->ops->freeze(ap); + + /* Stop the port DMA engines */ + if (ap->ops->port_stop) + ap->ops->port_stop(ap); + } + + /* Disable and clear host interrupts */ + writel(readl(mmio + HOST_CTL) & ~HOST_IRQ_EN, mmio + HOST_CTL); + readl(mmio + HOST_CTL); /* flush */ + writel(GENMASK(host->n_ports, 0), mmio + HOST_IRQ_STAT); +} +EXPORT_SYMBOL_GPL(ahci_platform_shutdown); + #ifdef CONFIG_PM_SLEEP /** * ahci_platform_suspend_host - Suspend an ahci-platform host diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h index a270f25e..1b0a17b 100644 --- a/include/linux/ahci_platform.h +++ b/include/linux/ahci_platform.h @@ -36,6 +36,8 @@ int ahci_platform_init_host(struct platform_device *pdev, const struct ata_port_info *pi_template, struct scsi_host_template *sht); +void ahci_platform_shutdown(struct platform_device *pdev); + int ahci_platform_suspend_host(struct device *dev); int ahci_platform_resume_host(struct device *dev); int ahci_platform_suspend(struct device *dev); -- Qualcomm Datacenter Technologies, Inc. on behalf of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
