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: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff 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);

drivers/ata/libata.h

@@ -153,6 +153,11 @@ extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
 extern void ata_scsi_dev_rescan(struct work_struct *work);
 extern int ata_bus_probe(struct ata_port *ap);
 
+/* libata-pmp.c */
+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_attach(struct ata_device *dev);
+
 /* libata-eh.c */
 extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
 extern void ata_scsi_error(struct Scsi_Host *host);

include/linux/libata.h

@@ -944,6 +944,25 @@ extern int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bit
 extern unsigned long ata_pci_default_filter(struct ata_device *, unsigned long);
 #endif /* CONFIG_PCI */
 
+/*
+ * PMP
+ */
+extern void sata_pmp_read_init_tf(struct ata_taskfile *tf,
+				  struct ata_device *dev, int pmp, int reg);
+extern u32 sata_pmp_read_val(const struct ata_taskfile *tf);
+extern void sata_pmp_write_init_tf(struct ata_taskfile *tf,
+				   struct ata_device *dev,
+				   int pmp, int reg, u32 val);
+extern int sata_pmp_std_prereset(struct ata_link *link, unsigned long deadline);
+extern int sata_pmp_std_hardreset(struct ata_link *link, unsigned int *class,
+				  unsigned long deadline);
+extern void sata_pmp_std_postreset(struct ata_link *link, unsigned int *class);
+extern void sata_pmp_do_eh(struct ata_port *ap,
+		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
+		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset,
+		ata_prereset_fn_t pmp_prereset, ata_reset_fn_t pmp_softreset,
+		ata_reset_fn_t pmp_hardreset, ata_postreset_fn_t pmp_postreset);
+
 /*
  * EH
  */