[PATCH v2] virtio_mmio: pm: Add notification handlers for restore and freeze

[Mikhail Golubev <Mikhail.Golubev@opensynergy.com>]

From: Yurii Danilovskyi <glyd@opensynergy.com>

Handle restore and freeze notifications from the PM core. Expose
these to individual virtio drivers that can quiesce and resume vq
operations.

Signed-off-by: Yurii Danilovskyi <glyd@opensynergy.com>
Signed-off-by: Mikhail Golubev <Mikhail.Golubev@opensynergy.com>
---
v2: fix build for defconfigs with CONFIG_PM/CONFIG_PM_SLEEP disabled

 drivers/virtio/virtio_mmio.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 56128b9c46eb..d5a2e8d2f31d 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -762,6 +762,26 @@ static void vm_unregister_cmdline_devices(void)
 
 #endif
 
+#ifdef CONFIG_PM_SLEEP
+static int virtio_mmio_freeze(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
+
+	return virtio_device_freeze(&vm_dev->vdev);
+}
+
+static int virtio_mmio_restore(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
+
+	return virtio_device_restore(&vm_dev->vdev);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(virtio_mmio_pm_ops, virtio_mmio_freeze, virtio_mmio_restore);
+
 /* Platform driver */
 
 static const struct of_device_id virtio_mmio_match[] = {
@@ -785,6 +805,7 @@ static struct platform_driver virtio_mmio_driver = {
 		.name	= "virtio-mmio",
 		.of_match_table	= virtio_mmio_match,
 		.acpi_match_table = ACPI_PTR(virtio_mmio_acpi_match),
+		.pm = &virtio_mmio_pm_ops,
 	},
 };
 
-- 
2.34.1


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