[PATCH 4.19 95/97] ata: ahci: Add shutdown to freeze hardware resources of ahci

[Greg Kroah-Hartman]

From: Prabhakar Kushwaha <pkushwaha@xxxxxxxxxxx>

commit 10a663a1b15134a5a714aa515e11425a44d4fdf7 upstream.

device_shutdown() called from reboot or power_shutdown expect
all devices to be shutdown. Same is true for even ahci pci driver.
As no ahci shutdown function is implemented, the ata subsystem
always remains alive with DMA & interrupt support. File system
related calls should not be honored after device_shutdown().

So defining ahci pci driver shutdown to freeze hardware (mask
interrupt, stop DMA engine and free DMA resources).

Signed-off-by: Prabhakar Kushwaha <pkushwaha@xxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/ata/ahci.c        |    7 +++++++
 drivers/ata/libata-core.c |   21 +++++++++++++++++++++
 include/linux/libata.h    |    1 +
 3 files changed, 29 insertions(+)

--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -96,6 +96,7 @@ enum board_ids {
 
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
 static void ahci_remove_one(struct pci_dev *dev);
+static void ahci_shutdown_one(struct pci_dev *dev);
 static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
 				 unsigned long deadline);
 static int ahci_avn_hardreset(struct ata_link *link, unsigned int *class,
@@ -609,6 +610,7 @@ static struct pci_driver ahci_pci_driver
 	.id_table		= ahci_pci_tbl,
 	.probe			= ahci_init_one,
 	.remove			= ahci_remove_one,
+	.shutdown		= ahci_shutdown_one,
 	.driver = {
 		.pm		= &ahci_pci_pm_ops,
 	},
@@ -1897,6 +1899,11 @@ static int ahci_init_one(struct pci_dev
 	return 0;
 }
 
+static void ahci_shutdown_one(struct pci_dev *pdev)
+{
+	ata_pci_shutdown_one(pdev);
+}
+
 static void ahci_remove_one(struct pci_dev *pdev)
 {
 	pm_runtime_get_noresume(&pdev->dev);
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6780,6 +6780,26 @@ void ata_pci_remove_one(struct pci_dev *
 	ata_host_detach(host);
 }
 
+void ata_pci_shutdown_one(struct pci_dev *pdev)
+{
+	struct ata_host *host = pci_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ata_port *ap = host->ports[i];
+
+		ap->pflags |= ATA_PFLAG_FROZEN;
+
+		/* 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);
+	}
+}
+
 /* move to PCI subsystem */
 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
 {
@@ -7400,6 +7420,7 @@ EXPORT_SYMBOL_GPL(ata_timing_cycle2mode)
 
 #ifdef CONFIG_PCI
 EXPORT_SYMBOL_GPL(pci_test_config_bits);
+EXPORT_SYMBOL_GPL(ata_pci_shutdown_one);
 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
 #ifdef CONFIG_PM
 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1236,6 +1236,7 @@ struct pci_bits {
 };
 
 extern int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits);
+extern void ata_pci_shutdown_one(struct pci_dev *pdev);
 extern void ata_pci_remove_one(struct pci_dev *pdev);
 
 #ifdef CONFIG_PM