[PATCH] libata: interrupt driven pio for libata-core

- add PIO_ST_FIRST for the state before sending ATAPI CDB or sending
"ATA PIO data out" first data block.
- add ATA_TFLAG_POLLING and ATA_DFLAG_CDB_INTR flags
- remove the ATA_FLAG_NOINTR flag since the interrupt handler is now
aware of the states
- modify ata_pio_sector() and atapi_pio_bytes() to work in the interrupt
context
- modify the ata_host_intr() to handle PIO interrupts
- modify ata_qc_issue_prot() to initialize states
- atapi_packet_task() changed to handle "ATA PIO data out" first data block
- support the pre-ATA4 ATAPI device which raise interrupt when ready to
receive CDB

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

include/linux/ata.h

@@ -181,6 +181,7 @@ enum {
 	ATA_TFLAG_ISADDR	= (1 << 1), /* enable r/w to nsect/lba regs */
 	ATA_TFLAG_DEVICE	= (1 << 2), /* enable r/w to device reg */
 	ATA_TFLAG_WRITE		= (1 << 3), /* data dir: host->dev==1 (write) */
+	ATA_TFLAG_POLLING	= (1 << 4), /* set nIEN to 1 and use polling */
 };
 
 enum ata_tf_protocols {
@@ -250,6 +251,8 @@ struct ata_taskfile {
 	  ((u64) (id)[(n) + 1] << 16) |	\
 	  ((u64) (id)[(n) + 0]) )
 
+#define ata_id_cdb_intr(id)	(((id)[0] & 0x60) == 0x20)
+
 static inline int atapi_cdb_len(u16 *dev_id)
 {
 	u16 tmp = dev_id[0] & 0x3;

include/linux/libata.h

@@ -97,6 +97,7 @@ enum {
 	ATA_DFLAG_LBA48		= (1 << 0), /* device supports LBA48 */
 	ATA_DFLAG_PIO		= (1 << 1), /* device currently in PIO mode */
 	ATA_DFLAG_LOCK_SECTORS	= (1 << 2), /* don't adjust max_sectors */
+	ATA_DFLAG_CDB_INTR	= (1 << 3), /* device asserts INTRQ when ready for CDB */
 
 	ATA_DEV_UNKNOWN		= 0,	/* unknown device */
 	ATA_DEV_ATA		= 1,	/* ATA device */
@@ -115,8 +116,6 @@ enum {
 	ATA_FLAG_MMIO		= (1 << 6), /* use MMIO, not PIO */
 	ATA_FLAG_SATA_RESET	= (1 << 7), /* use COMRESET */
 	ATA_FLAG_PIO_DMA	= (1 << 8), /* PIO cmds via DMA */
-	ATA_FLAG_NOINTR		= (1 << 9), /* FIXME: Remove this once
-					     * proper HSM is in place. */
 
 	ATA_QCFLAG_ACTIVE	= (1 << 1), /* cmd not yet ack'd to scsi lyer */
 	ATA_QCFLAG_SG		= (1 << 3), /* have s/g table? */
@@ -165,6 +164,7 @@ enum hsm_task_states {
 	HSM_ST_LAST,
 	HSM_ST_LAST_POLL,
 	HSM_ST_ERR,
+	HSM_ST_FIRST,
 };
 
 /* forward declarations */