[PATCH 1/2] ata: libahci: move ahci platform shutdown function to libahci

[Hanna Hawa <hhhawa@amazon.com>]

Move ahci platform shutdown function to libahci as preparation to add
shutdown handler for PCIe AHCI.

Signed-off-by: Hanna Hawa <hhhawa@amazon.com>
---
 drivers/ata/ahci.h             |  1 +
 drivers/ata/libahci.c          | 33 +++++++++++++++++++++++++++++++++
 drivers/ata/libahci_platform.c | 20 +-------------------
 3 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 3dbf398c92ea..df84dfdf9037 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -418,6 +418,7 @@ void ahci_set_em_messages(struct ahci_host_priv *hpriv,
 int ahci_reset_em(struct ata_host *host);
 void ahci_print_info(struct ata_host *host, const char *scc_s);
 int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht);
+void ahci_common_shutdown(struct ata_host *host);
 void ahci_error_handler(struct ata_port *ap);
 u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked);
 
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index bff369d9a1a7..f5dd5d66c442 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -2602,6 +2602,39 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
 }
 EXPORT_SYMBOL_GPL(ahci_host_activate);
 
+/**
+ * ahci_common_shutdown - Disable interrupts and stop DMA for host ports
+ * @host: target ATA host
+ *
+ * This common function is called during system shutdown and performs the
+ * minimal deconfiguration required to ensure that an ahci host cannot corrupt
+ * or otherwise interfere with a new kernel being started with kexec.
+ */
+void ahci_common_shutdown(struct ata_host *host)
+{
+	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_common_shutdown);
+
 MODULE_AUTHOR("Jeff Garzik");
 MODULE_DESCRIPTION("Common AHCI SATA low-level routines");
 MODULE_LICENSE("GPL");
diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index 8befce036af8..dd2bfa3986f8 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -680,26 +680,8 @@ static void ahci_host_stop(struct ata_host *host)
 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);
+	ahci_common_shutdown(host);
 }
 EXPORT_SYMBOL_GPL(ahci_platform_shutdown);
 
-- 
2.17.1