[libata] add ata_tf_{to,from}_fis helpers

drivers/scsi/libata-core.c

@@ -439,6 +439,77 @@ u8 ata_check_status_mmio(struct ata_port *ap)
        	return readb((void *) ap->ioaddr.status_addr);
 }
 
+/**
+ *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
+ *	@tf: Taskfile to convert
+ *	@fis: Buffer into which data will output
+ *
+ *	Converts a standard ATA taskfile to a Serial ATA
+ *	FIS structure (Register - Host to Device).
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+void ata_tf_to_fis(struct ata_taskfile *tf, u8 *fis, u8 pmp)
+{
+	fis[0] = 0x27;	/* Register - Host to Device FIS */
+	fis[1] = (pmp & 0xf) | (1 << 7); /* Port multiplier number,
+					    bit 7 indicates Command FIS */
+	fis[2] = tf->command;
+	fis[3] = tf->feature;
+
+	fis[4] = tf->lbal;
+	fis[5] = tf->lbam;
+	fis[6] = tf->lbah;
+	fis[7] = tf->device;
+
+	fis[8] = tf->hob_lbal;
+	fis[9] = tf->hob_lbam;
+	fis[10] = tf->hob_lbah;
+	fis[11] = tf->hob_feature;
+
+	fis[12] = tf->nsect;
+	fis[13] = tf->hob_nsect;
+	fis[14] = 0;
+	fis[15] = tf->ctl;
+
+	fis[16] = 0;
+	fis[17] = 0;
+	fis[18] = 0;
+	fis[19] = 0;
+}
+
+/**
+ *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
+ *	@fis: Buffer from which data will be input
+ *	@tf: Taskfile to output
+ *
+ *	Converts a standard ATA taskfile to a Serial ATA
+ *	FIS structure (Register - Host to Device).
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+void ata_tf_from_fis(u8 *fis, struct ata_taskfile *tf)
+{
+	tf->command	= fis[2];	/* status */
+	tf->feature	= fis[3];	/* error */
+
+	tf->lbal	= fis[4];
+	tf->lbam	= fis[5];
+	tf->lbah	= fis[6];
+	tf->device	= fis[7];
+
+	tf->hob_lbal	= fis[8];
+	tf->hob_lbam	= fis[9];
+	tf->hob_lbah	= fis[10];
+
+	tf->nsect	= fis[12];
+	tf->hob_nsect	= fis[13];
+}
+
 /**
  *	ata_prot_to_cmd - determine which read/write opcodes to use
  *	@protocol: ATA_PROT_xxx taskfile protocol
@@ -3512,6 +3583,8 @@ EXPORT_SYMBOL_GPL(ata_tf_load_pio);
 EXPORT_SYMBOL_GPL(ata_tf_load_mmio);
 EXPORT_SYMBOL_GPL(ata_tf_read_pio);
 EXPORT_SYMBOL_GPL(ata_tf_read_mmio);
+EXPORT_SYMBOL_GPL(ata_tf_to_fis);
+EXPORT_SYMBOL_GPL(ata_tf_from_fis);
 EXPORT_SYMBOL_GPL(ata_check_status_pio);
 EXPORT_SYMBOL_GPL(ata_check_status_mmio);
 EXPORT_SYMBOL_GPL(ata_exec_command_pio);

include/linux/libata.h

@@ -392,6 +392,8 @@ extern void ata_tf_load_pio(struct ata_port *ap, struct ata_taskfile *tf);
 extern void ata_tf_load_mmio(struct ata_port *ap, struct ata_taskfile *tf);
 extern void ata_tf_read_pio(struct ata_port *ap, struct ata_taskfile *tf);
 extern void ata_tf_read_mmio(struct ata_port *ap, struct ata_taskfile *tf);
+extern void ata_tf_to_fis(struct ata_taskfile *tf, u8 *fis, u8 pmp);
+extern void ata_tf_from_fis(u8 *fis, struct ata_taskfile *tf);
 extern u8 ata_check_status_pio(struct ata_port *ap);
 extern u8 ata_check_status_mmio(struct ata_port *ap);
 extern void ata_exec_command_pio(struct ata_port *ap, struct ata_taskfile *tf);