ata: parport_pc: add 16-bit and 8-bit fast EPP transfer flags

PARPORT_EPP_FAST flag currently uses 32-bit I/O port access for data
read/write (insl/outsl).
Add PARPORT_EPP_FAST_16 and PARPORT_EPP_FAST_8 that use insw/outsw
and insb/outsb (and PARPORT_EPP_FAST_32 as alias for PARPORT_EPP_FAST).
Signed-off-by: Ondrej Zary <linux@zary.sk>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

drivers/parport/parport_pc.c

@@ -305,9 +305,15 @@ static size_t parport_pc_epp_read_data(struct parport *port, void *buf,
 		}
 		return got;
 	}
-	if ((flags & PARPORT_EPP_FAST) && (length > 1)) {
-		if (!(((long)buf | length) & 0x03))
+	if ((length > 1) && ((flags & PARPORT_EPP_FAST_32)
+			   || flags & PARPORT_EPP_FAST_16
+			   || flags & PARPORT_EPP_FAST_8)) {
+		if ((flags & PARPORT_EPP_FAST_32)
+		    && !(((long)buf | length) & 0x03))
 			insl(EPPDATA(port), buf, (length >> 2));
+		else if ((flags & PARPORT_EPP_FAST_16)
+			 && !(((long)buf | length) & 0x01))
+			insw(EPPDATA(port), buf, length >> 1);
 		else
 			insb(EPPDATA(port), buf, length);
 		if (inb(STATUS(port)) & 0x01) {
@@ -334,9 +340,15 @@ static size_t parport_pc_epp_write_data(struct parport *port, const void *buf,
 {
 	size_t written = 0;
 
-	if ((flags & PARPORT_EPP_FAST) && (length > 1)) {
-		if (!(((long)buf | length) & 0x03))
+	if ((length > 1) && ((flags & PARPORT_EPP_FAST_32)
+			   || flags & PARPORT_EPP_FAST_16
+			   || flags & PARPORT_EPP_FAST_8)) {
+		if ((flags & PARPORT_EPP_FAST_32)
+		    && !(((long)buf | length) & 0x03))
 			outsl(EPPDATA(port), buf, (length >> 2));
+		else if ((flags & PARPORT_EPP_FAST_16)
+			 && !(((long)buf | length) & 0x01))
+			outsw(EPPDATA(port), buf, length >> 1);
 		else
 			outsb(EPPDATA(port), buf, length);
 		if (inb(STATUS(port)) & 0x01) {

include/uapi/linux/parport.h

@@ -90,6 +90,9 @@ typedef enum {
 /* Flags for block transfer operations. */
 #define PARPORT_EPP_FAST		(1<<0) /* Unreliable counts. */
 #define PARPORT_W91284PIC		(1<<1) /* have a Warp9 w91284pic in the device */
+#define PARPORT_EPP_FAST_32		PARPORT_EPP_FAST /* 32-bit EPP transfers */
+#define PARPORT_EPP_FAST_16		(1<<2) /* 16-bit EPP transfers */
+#define PARPORT_EPP_FAST_8		(1<<3) /* 8-bit EPP transfers */
 
 /* The rest is for the kernel only */
 #endif /* _UAPI_PARPORT_H_ */