[SCSI] aic79xx: make driver respect nvram for IU and QAS settings

This patch allows the Adaptec firmware to pass on its values for Packetize and
QAS.  To do this, the settings max_iu and max_qas have been introduced into
the SPI transport class and populated from the adaptec NVram tables.  Domain
validation in the SPI transport class will respect the max settings when
configuring to the highest possible speed for testing.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/aic7xxx/aic79xx_osm.c

@@ -627,19 +627,15 @@ ahd_linux_target_alloc(struct scsi_target *starget)
 					    starget->id, &tstate);
 
 		if ((flags  & CFPACKETIZED) == 0) {
-			/* Do not negotiate packetized transfers */
-			spi_rd_strm(starget) = 0;
-			spi_pcomp_en(starget) = 0;
-			spi_rti(starget) = 0;
-			spi_wr_flow(starget) = 0;
-			spi_hold_mcs(starget) = 0;
+			/* don't negotiate packetized (IU) transfers */
+			spi_max_iu(starget) = 0;
 		} else {
 			if ((ahd->features & AHD_RTI) == 0)
 				spi_rti(starget) = 0;
 		}
 
 		if ((flags & CFQAS) == 0)
-			spi_qas(starget) = 0;
+			spi_max_qas(starget) = 0;
 
 		/* Transinfo values have been set to BIOS settings */
 		spi_max_width(starget) = (flags & CFWIDEB) ? 1 : 0;

drivers/scsi/scsi_transport_spi.c

@@ -234,8 +234,10 @@ static int spi_setup_transport_attrs(struct transport_container *tc,
 	spi_width(starget) = 0;	/* narrow */
 	spi_max_width(starget) = 1;
 	spi_iu(starget) = 0;	/* no IU */
+	spi_max_iu(starget) = 1;
 	spi_dt(starget) = 0;	/* ST */
 	spi_qas(starget) = 0;
+	spi_max_qas(starget) = 1;
 	spi_wr_flow(starget) = 0;
 	spi_rd_strm(starget) = 0;
 	spi_rti(starget) = 0;
@@ -360,9 +362,9 @@ static DEVICE_ATTR(field, S_IRUGO,				\
 /* The Parallel SCSI Tranport Attributes: */
 spi_transport_max_attr(offset, "%d\n");
 spi_transport_max_attr(width, "%d\n");
-spi_transport_rd_attr(iu, "%d\n");
+spi_transport_max_attr(iu, "%d\n");
 spi_transport_rd_attr(dt, "%d\n");
-spi_transport_rd_attr(qas, "%d\n");
+spi_transport_max_attr(qas, "%d\n");
 spi_transport_rd_attr(wr_flow, "%d\n");
 spi_transport_rd_attr(rd_strm, "%d\n");
 spi_transport_rd_attr(rti, "%d\n");
@@ -874,13 +876,13 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
 
 	/* try QAS requests; this should be harmless to set if the
 	 * target supports it */
-	if (scsi_device_qas(sdev)) {
+	if (scsi_device_qas(sdev) && spi_max_qas(starget)) {
 		DV_SET(qas, 1);
 	} else {
 		DV_SET(qas, 0);
 	}
 
-	if (scsi_device_ius(sdev) && min_period < 9) {
+	if (scsi_device_ius(sdev) && spi_max_iu(starget) && min_period < 9) {
 		/* This u320 (or u640). Set IU transfers */
 		DV_SET(iu, 1);
 		/* Then set the optional parameters */
@@ -1412,12 +1414,18 @@ static mode_t target_attribute_is_visible(struct kobject *kobj,
 	else if (attr == &dev_attr_iu.attr &&
 		 spi_support_ius(starget))
 		return TARGET_ATTRIBUTE_HELPER(iu);
+	else if (attr == &dev_attr_max_iu.attr &&
+		 spi_support_ius(starget))
+		return TARGET_ATTRIBUTE_HELPER(iu);
 	else if (attr == &dev_attr_dt.attr &&
 		 spi_support_dt(starget))
 		return TARGET_ATTRIBUTE_HELPER(dt);
 	else if (attr == &dev_attr_qas.attr &&
 		 spi_support_qas(starget))
 		return TARGET_ATTRIBUTE_HELPER(qas);
+	else if (attr == &dev_attr_max_qas.attr &&
+		 spi_support_qas(starget))
+		return TARGET_ATTRIBUTE_HELPER(qas);
 	else if (attr == &dev_attr_wr_flow.attr &&
 		 spi_support_ius(starget))
 		return TARGET_ATTRIBUTE_HELPER(wr_flow);
@@ -1447,8 +1455,10 @@ static struct attribute *target_attributes[] = {
 	&dev_attr_width.attr,
 	&dev_attr_max_width.attr,
 	&dev_attr_iu.attr,
+	&dev_attr_max_iu.attr,
 	&dev_attr_dt.attr,
 	&dev_attr_qas.attr,
+	&dev_attr_max_qas.attr,
 	&dev_attr_wr_flow.attr,
 	&dev_attr_rd_strm.attr,
 	&dev_attr_rti.attr,

include/scsi/scsi_transport_spi.h

@@ -36,8 +36,10 @@ struct spi_transport_attrs {
 	unsigned int width:1;	/* 0 - narrow, 1 - wide */
 	unsigned int max_width:1;
 	unsigned int iu:1;	/* Information Units enabled */
+	unsigned int max_iu:1;
 	unsigned int dt:1;	/* DT clocking enabled */
 	unsigned int qas:1;	/* Quick Arbitration and Selection enabled */
+	unsigned int max_qas:1;
 	unsigned int wr_flow:1;	/* Write Flow control enabled */
 	unsigned int rd_strm:1;	/* Read streaming enabled */
 	unsigned int rti:1;	/* Retain Training Information */
@@ -77,8 +79,10 @@ struct spi_host_attrs {
 #define spi_width(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->width)
 #define spi_max_width(x) (((struct spi_transport_attrs *)&(x)->starget_data)->max_width)
 #define spi_iu(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->iu)
+#define spi_max_iu(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->max_iu)
 #define spi_dt(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->dt)
 #define spi_qas(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->qas)
+#define spi_max_qas(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->max_qas)
 #define spi_wr_flow(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->wr_flow)
 #define spi_rd_strm(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->rd_strm)
 #define spi_rti(x)	(((struct spi_transport_attrs *)&(x)->starget_data)->rti)