libata: implement LPM support for port multipliers

Port multipliers can do DIPM on fan-out links fine.  Implement support
for it.  Tested w/ SIMG 57xx and marvell PMPs.  Both the host and
fan-out links enter power save modes nicely.

SIMG 37xx and 47xx report link offline on SStatus causing EH to detach
the devices.  Blacklisted.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 55a6f41..7c070a4 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -176,6 +176,8 @@
 #ifdef CONFIG_SATA_PMP
 extern int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *val);
 extern int sata_pmp_scr_write(struct ata_link *link, int reg, u32 val);
+extern int sata_pmp_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
+			    unsigned hints);
 extern int sata_pmp_attach(struct ata_device *dev);
 #else /* CONFIG_SATA_PMP */
 static inline int sata_pmp_scr_read(struct ata_link *link, int reg, u32 *val)
@@ -188,6 +190,12 @@
 	return -EINVAL;
 }
 
+static inline int sata_pmp_set_lpm(struct ata_link *link,
+				   enum ata_lpm_policy policy, unsigned hints)
+{
+	return -EINVAL;
+}
+
 static inline int sata_pmp_attach(struct ata_device *dev)
 {
 	return -EINVAL;