libata-pmp: implement Port Multiplier support

Implement Port Multiplier support.  To support PMP, a LLDD has to
supply ops->pmp_read() and pmp_write().  If non-null, ->pmp_attach and
->pmp_detach are called on PMP attach and detach, respectively.

->pmp_read/write() can be called while the port is frozen, so they
must be implemented by polling.  This patch supplies several helpers
to ease ->pmp_read/write() implementation.

Also, irq_handler and error_handler must be PMP aware.  Most of PMP
aware EH can be done by calling ata_pmp_do_eh() with appropriate
methods.  PMP EH uses separate set of reset methods and this patch
implements standard prereset, hardreset and postreset methods.

This patch only implements PMP support.  The next patch will integrate
PMP into the reset of libata and thus enable PMP support.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/Makefile

@@ -71,5 +71,6 @@ obj-$(CONFIG_ATA_GENERIC)	+= ata_generic.o
 # Should be last libata driver
 obj-$(CONFIG_PATA_LEGACY)	+= pata_legacy.o
 
-libata-objs	:= libata-core.o libata-scsi.o libata-sff.o libata-eh.o
+libata-objs	:= libata-core.o libata-scsi.o libata-sff.o libata-eh.o \
+		   libata-pmp.o
 libata-$(CONFIG_ATA_ACPI)	+= libata-acpi.o

drivers/ata/libata-core.c

@@ -3865,6 +3865,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	{ "IOMEGA  ZIP 250       ATAPI", NULL,	ATA_HORKAGE_NODMA }, /* temporary fix */
 	{ "IOMEGA  ZIP 250       ATAPI       Floppy",
 				NULL,		ATA_HORKAGE_NODMA },
+	/* Odd clown on sil3726/4726 PMPs */
+	{ "Config  Disk",	NULL,		ATA_HORKAGE_NODMA |
+						ATA_HORKAGE_SKIP_PM },
 
 	/* Weird ATAPI devices */
 	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 },
@@ -7251,6 +7254,14 @@ EXPORT_SYMBOL_GPL(ata_pci_default_filter);
 EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
 #endif /* CONFIG_PCI */
 
+EXPORT_SYMBOL_GPL(sata_pmp_read_init_tf);
+EXPORT_SYMBOL_GPL(sata_pmp_read_val);
+EXPORT_SYMBOL_GPL(sata_pmp_write_init_tf);
+EXPORT_SYMBOL_GPL(sata_pmp_std_prereset);
+EXPORT_SYMBOL_GPL(sata_pmp_std_hardreset);
+EXPORT_SYMBOL_GPL(sata_pmp_std_postreset);
+EXPORT_SYMBOL_GPL(sata_pmp_do_eh);
+
 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
 EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
 EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);