ncr5380: Implement NCR5380_dma_xfer_len and remove LIMIT_TRANSFERSIZE macro

Follow the example of the atari_NCR5380.c core driver and adopt the
NCR5380_dma_xfer_len() hook. Implement NCR5380_dma_xfer_len() for dtc.c
and g_NCR5380.c to take care of the limitations of these cards. Keep the
default for drivers using PSEUDO_DMA.

Eliminate the unused macro LIMIT_TRANSFERSIZE.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

11 files changed, 56 insertions, 31 deletions

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 6a030139b41f..91eac63b5239 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -201,11 +201,6 @@
  * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
  *      override-configure an IRQ.
  *
- * LIMIT_TRANSFERSIZE - if defined, limit the pseudo-dma transfers to 512
- *      bytes at a time.  Since interrupts are disabled by default during
- *      these transfers, we might need this to give reasonable interrupt
- *      service time if the transfer size gets too large.
- *
  * LINKED - if defined, linked commands are supported.
  *
  * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
@@ -2000,29 +1995,12 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance) {
                                  */
 
 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
-                                /* KLL
-                                 * PSEUDO_DMA is defined here. If this is the g_NCR5380
-                                 * driver then it will always be defined, so the
-                                 * FLAG_NO_PSEUDO_DMA is used to inhibit PDMA in the base
-                                 * NCR5380 case.  I think this is a fairly clean solution.
-                                 * We supplement these 2 if's with the flag.
-                                 */
-#ifdef NCR5380_dma_xfer_len
-                                if (!cmd->device->borken && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && (transfersize = NCR5380_dma_xfer_len(instance, cmd)) != 0) {
-#else
-                                transfersize = cmd->transfersize;
-
-#ifdef LIMIT_TRANSFERSIZE       /* If we have problems with interrupt service */
-                                if (transfersize > 512)
-                                        transfersize = 512;
-#endif                          /* LIMIT_TRANSFERSIZE */
-
-                                if (!cmd->device->borken && transfersize && !(hostdata->flags & FLAG_NO_PSEUDO_DMA) && cmd->SCp.this_residual && !(cmd->SCp.this_residual % transfersize)) {
-                                        /* Limit transfers to 32K, for xx400 & xx406
-                                         * pseudoDMA that transfers in 128 bytes blocks. */
-                                        if (transfersize > 32 * 1024)
-                                                transfersize = 32 * 1024;
-#endif
+                                transfersize = 0;
+                                if (!cmd->device->borken &&
+                                    !(hostdata->flags & FLAG_NO_PSEUDO_DMA))
+                                        transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);
+
+                                if (transfersize) {
                                         len = transfersize;
                                         if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
                                                 /*
diff --git a/drivers/scsi/arm/cumana_1.c b/drivers/scsi/arm/cumana_1.c
index 0d0cb62b8cdb..f9fb8dabdbbd 100644
--- a/drivers/scsi/arm/cumana_1.c
+++ b/drivers/scsi/arm/cumana_1.c
@@ -22,6 +22,9 @@
 #define priv(host)                      ((struct NCR5380_hostdata *)(host)->hostdata)
 #define NCR5380_read(reg)               cumanascsi_read(instance, reg)
 #define NCR5380_write(reg, value)       cumanascsi_write(instance, reg, value)
+
+#define NCR5380_dma_xfer_len(instance, cmd, phase)      (cmd->transfersize)
+
 #define NCR5380_intr                    cumanascsi_intr
 #define NCR5380_queue_command           cumanascsi_queue_command
 #define NCR5380_info                    cumanascsi_info
diff --git a/drivers/scsi/arm/oak.c b/drivers/scsi/arm/oak.c
index db337b998299..d95a1d4f4e02 100644
--- a/drivers/scsi/arm/oak.c
+++ b/drivers/scsi/arm/oak.c
@@ -26,6 +26,8 @@
 #define NCR5380_write(reg, value) \
         writeb(value, priv(instance)->base + ((reg) << 2))
 
+#define NCR5380_dma_xfer_len(instance, cmd, phase)      (cmd->transfersize)
+
 #define NCR5380_queue_command           oakscsi_queue_command
 #define NCR5380_info                    oakscsi_info
 #define NCR5380_show_info               oakscsi_show_info
diff --git a/drivers/scsi/atari_NCR5380.c b/drivers/scsi/atari_NCR5380.c
index 64ee92090de3..59b378057198 100644
--- a/drivers/scsi/atari_NCR5380.c
+++ b/drivers/scsi/atari_NCR5380.c
@@ -2170,11 +2170,13 @@ static void NCR5380_information_transfer(struct Scsi_Host *instance)
                                  */
 
 #if defined(REAL_DMA)
-                                if (
 #if !defined(CONFIG_SUN3)
-                                    !cmd->device->borken &&
+                                transfersize = 0;
+                                if (!cmd->device->borken)
 #endif
-                                    (transfersize = NCR5380_dma_xfer_len(instance, cmd, phase)) >= DMA_MIN_SIZE) {
+                                        transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);
+
+                                if (transfersize >= DMA_MIN_SIZE) {
                                         len = transfersize;
                                         cmd->SCp.phase = phase;
                                         if (NCR5380_transfer_dma(instance, &phase,
diff --git a/drivers/scsi/dtc.c b/drivers/scsi/dtc.c
index bc856c8ba0dd..010d9b13aae7 100644
--- a/drivers/scsi/dtc.c
+++ b/drivers/scsi/dtc.c
@@ -419,6 +419,20 @@ static inline int NCR5380_pwrite(struct Scsi_Host *instance, unsigned char *src,
         return (0);
 }
 
+static int dtc_dma_xfer_len(struct scsi_cmnd *cmd)
+{
+        int transfersize = cmd->transfersize;
+
+        /* Limit transfers to 32K, for xx400 & xx406
+         * pseudoDMA that transfers in 128 bytes blocks.
+         */
+        if (transfersize > 32 * 1024 && cmd->SCp.this_residual &&
+            !(cmd->SCp.this_residual % transfersize))
+                transfersize = 32 * 1024;
+
+        return transfersize;
+}
+
 MODULE_LICENSE("GPL");
 
 #include "NCR5380.c"
diff --git a/drivers/scsi/dtc.h b/drivers/scsi/dtc.h
index 07b0ac98817c..e6c09a9174ce 100644
--- a/drivers/scsi/dtc.h
+++ b/drivers/scsi/dtc.h
@@ -27,6 +27,9 @@
 #define NCR5380_read(reg) (readb(DTC_address(reg)))
 #define NCR5380_write(reg, value) (writeb(value, DTC_address(reg)))
 
+#define NCR5380_dma_xfer_len(instance, cmd, phase) \
+        dtc_dma_xfer_len(cmd)
+
 #define NCR5380_intr                    dtc_intr
 #define NCR5380_queue_command           dtc_queue_command
 #define NCR5380_abort                   dtc_abort
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index afd092ff0c2e..5b3e03ad50ce 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -699,6 +699,21 @@ static inline int NCR5380_pwrite(struct Scsi_Host *instance, unsigned char *src,
                 ;       // TIMEOUT
         return 0;
 }
+
+static int generic_NCR5380_dma_xfer_len(struct scsi_cmnd *cmd)
+{
+        int transfersize = cmd->transfersize;
+
+        /* Limit transfers to 32K, for xx400 & xx406
+         * pseudoDMA that transfers in 128 bytes blocks.
+         */
+        if (transfersize > 32 * 1024 && cmd->SCp.this_residual &&
+            !(cmd->SCp.this_residual % transfersize))
+                transfersize = 32 * 1024;
+
+        return transfersize;
+}
+
 #endif /* PSEUDO_DMA */
 
 /*
diff --git a/drivers/scsi/g_NCR5380.h b/drivers/scsi/g_NCR5380.h
index 5c656f163beb..0056790a9cbe 100644
--- a/drivers/scsi/g_NCR5380.h
+++ b/drivers/scsi/g_NCR5380.h
@@ -73,6 +73,9 @@
 
 #endif
 
+#define NCR5380_dma_xfer_len(instance, cmd, phase) \
+        generic_NCR5380_dma_xfer_len(cmd)
+
 #define NCR5380_intr generic_NCR5380_intr
 #define NCR5380_queue_command generic_NCR5380_queue_command
 #define NCR5380_abort generic_NCR5380_abort
diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c
index 1317f54bab92..f8ed2acd1456 100644
--- a/drivers/scsi/mac_scsi.c
+++ b/drivers/scsi/mac_scsi.c
@@ -38,6 +38,7 @@
 
 #define NCR5380_pread                   macscsi_pread
 #define NCR5380_pwrite                  macscsi_pwrite
+#define NCR5380_dma_xfer_len(instance, cmd, phase)      (cmd->transfersize)
 
 #define NCR5380_intr                    macscsi_intr
 #define NCR5380_queue_command           macscsi_queue_command
diff --git a/drivers/scsi/pas16.h b/drivers/scsi/pas16.h
index 7247b67fb111..a827a7c1c133 100644
--- a/drivers/scsi/pas16.h
+++ b/drivers/scsi/pas16.h
@@ -110,6 +110,8 @@
 #define NCR5380_read(reg) ( inb(PAS16_io_port(reg)) )
 #define NCR5380_write(reg, value) ( outb((value),PAS16_io_port(reg)) )
 
+#define NCR5380_dma_xfer_len(instance, cmd, phase)      (cmd->transfersize)
+
 #define NCR5380_intr pas16_intr
 #define NCR5380_queue_command pas16_queue_command
 #define NCR5380_abort pas16_abort
diff --git a/drivers/scsi/t128.h b/drivers/scsi/t128.h
index ca93c97cf4ba..16691d5fb81b 100644
--- a/drivers/scsi/t128.h
+++ b/drivers/scsi/t128.h
@@ -84,6 +84,8 @@
 #define NCR5380_read(reg) readb(T128_address(reg))
 #define NCR5380_write(reg, value) writeb((value),(T128_address(reg)))
 
+#define NCR5380_dma_xfer_len(instance, cmd, phase)      (cmd->transfersize)
+
 #define NCR5380_intr t128_intr
 #define NCR5380_queue_command t128_queue_command
 #define NCR5380_abort t128_abort