libata: implement ata_platform_remove_one()

This relatively simple boiler-plate code is repeated in several platform
drivers. We should implement a common version in libata.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/libata-core.c

@@ -67,6 +67,7 @@
 #include <linux/cdrom.h>
 #include <linux/ratelimit.h>
 #include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
 
 #include "libata.h"
 #include "libata-transport.h"
@@ -6382,6 +6383,26 @@ int ata_pci_device_resume(struct pci_dev *pdev)
 
 #endif /* CONFIG_PCI */
 
+/**
+ *	ata_platform_remove_one - Platform layer callback for device removal
+ *	@pdev: Platform device that was removed
+ *
+ *	Platform layer indicates to libata via this hook that hot-unplug or
+ *	module unload event has occurred.  Detach all ports.  Resource
+ *	release is handled via devres.
+ *
+ *	LOCKING:
+ *	Inherited from platform layer (may sleep).
+ */
+int ata_platform_remove_one(struct platform_device *pdev)
+{
+	struct ata_host *host = platform_get_drvdata(pdev);
+
+	ata_host_detach(host);
+
+	return 0;
+}
+
 static int __init ata_parse_force_one(char **cur,
 				      struct ata_force_ent *force_ent,
 				      const char **reason)
@@ -6877,6 +6898,8 @@ EXPORT_SYMBOL_GPL(ata_pci_device_resume);
 #endif /* CONFIG_PM */
 #endif /* CONFIG_PCI */
 
+EXPORT_SYMBOL_GPL(ata_platform_remove_one);
+
 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
 EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
 EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);