[PATCH 28/29] atari_NCR5380: Refactor Falcon special cases

Finn Thain
2014-10-02T06:56:56Z

[-- Attachment #1: atari_NCR5380-refactor-falcon-special-case --]
[-- Type: text/plain, Size: 8539 bytes --]

Make the atari_NCR5380.c core driver usable by sun3_scsi, mac_scsi and others
by moving some of the Falcon-specific code out of the core driver: !IS_A_TT,
atari_read_overruns and falcon_dont_release. Replace these with hostdata
variables and flags. FLAG_CHECK_LAST_BYTE_SENT is unused in atari_NCR5380.c
so don't set it.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>

---
drivers/scsi/NCR5380.h | 4 ++++
drivers/scsi/atari_NCR5380.c | 30 +++++++++++++++---------------
drivers/scsi/atari_scsi.c | 21 ++++++++++++---------
3 files changed, 31 insertions(+), 24 deletions(-)

Index: linux/drivers/scsi/atari_scsi.c
===================================================================
--- linux.orig/drivers/scsi/atari_scsi.c 2014-10-02 16:56:24.000000000 +1000
+++ linux/drivers/scsi/atari_scsi.c 2014-10-02 16:56:25.000000000 +1000
@@ -196,8 +196,6 @@ static char *atari_dma_orig_addr;
/* mask for address bits that can't be used with the ST-DMA */
static unsigned long atari_dma_stram_mask;
#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
-/* number of bytes to cut from a transfer to handle NCR overruns */
-static int atari_read_overruns;
#endif

static int setup_can_queue = -1;
@@ -446,8 +444,6 @@ static void atari_scsi_fetch_restbytes(v
#endif /* REAL_DMA */

-static int falcon_dont_release = 0;
-
/* This function releases the lock on the DMA chip if there is no
* connected command and the disconnected queue is empty.
*/
@@ -464,7 +460,7 @@ static void falcon_release_lock_if_possi
if (!hostdata->disconnected_queue &&
!hostdata->issue_queue &&
!hostdata->connected &&
- !falcon_dont_release &&
+ !hostdata->retain_dma_intr &&
stdma_is_locked_by(scsi_falcon_intr))
stdma_release();

@@ -846,6 +842,7 @@ static int __init atari_scsi_probe(struc
{
struct Scsi_Host *instance;
int error;
+ int host_flags = 0;

if (!MACH_IS_ATARI)
return -ENODEV;
@@ -945,7 +942,9 @@ static int __init atari_scsi_probe(struc
else
instance->irq = IRQ_NONE;

- NCR5380_init(instance, 0);
+ host_flags |= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP;
+
+ NCR5380_init(instance, host_flags);

if (IS_A_TT()) {
error = request_irq(instance->irq, scsi_tt_intr, 0,
@@ -968,12 +967,16 @@ static int __init atari_scsi_probe(struc
*
* In principle it should be sufficient to do max. 1 byte with
* PIO, but there is another problem on the Medusa with the DMA
- * rest data register. So 'atari_read_overruns' is currently set
+ * rest data register. So read_overruns is currently set
* to 4 to avoid having transfers that aren't a multiple of 4.
* If the rest data bug is fixed, this can be lowered to 1.
*/
- if (MACH_IS_MEDUSA)
- atari_read_overruns = 4;
+ if (MACH_IS_MEDUSA) {
+ struct NCR5380_hostdata *hostdata =
+ shost_priv(instance);
+
+ hostdata->read_overruns = 4;
+ }
#endif
} else {
/* Nothing to do for the interrupt: the ST-DMA is initialized
Index: linux/drivers/scsi/NCR5380.h
===================================================================
--- linux.orig/drivers/scsi/NCR5380.h 2014-10-02 16:56:14.000000000 +1000
+++ linux/drivers/scsi/NCR5380.h 2014-10-02 16:56:25.000000000 +1000
@@ -237,6 +237,7 @@
#define FLAG_NCR53C400 4 /* NCR53c400 */
#define FLAG_NO_PSEUDO_DMA 8 /* Inhibit DMA */
#define FLAG_DTC3181E 16 /* DTC3181E */
+#define FLAG_LATE_DMA_SETUP 32 /* Setup NCR before DMA H/W */

#ifndef ASM
struct NCR5380_hostdata {
@@ -265,6 +266,9 @@ struct NCR5380_hostdata {
struct delayed_work coroutine; /* our co-routine */
struct scsi_eh_save ses;
char info[256];
+ int read_overruns; /* number of bytes to cut from a
+ * transfer to handle chip overruns */
+ int retain_dma_intr;
#ifdef PSEUDO_DMA
unsigned spin_max_r;
unsigned spin_max_w;
Index: linux/drivers/scsi/atari_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/atari_NCR5380.c 2014-10-02 16:56:24.000000000 +1000
+++ linux/drivers/scsi/atari_NCR5380.c 2014-10-02 16:56:25.000000000 +1000
@@ -837,7 +837,7 @@ static int __init NCR5380_init(struct Sc
hostdata->connected = NULL;
hostdata->issue_queue = NULL;
hostdata->disconnected_queue = NULL;
- hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
+ hostdata->flags = flags;

if (!the_template) {
the_template = instance->hostt;
@@ -1053,7 +1053,7 @@ static void NCR5380_main(struct work_str
hostdata->issue_queue = NEXT(tmp);
}
SET_NEXT(tmp, NULL);
- falcon_dont_release++;
+ hostdata->retain_dma_intr++;

/* reenable interrupts after finding one */
local_irq_restore(flags);
@@ -1081,7 +1081,7 @@ static void NCR5380_main(struct work_str
cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
#endif
if (!NCR5380_select(instance, tmp)) {
- falcon_dont_release--;
+ hostdata->retain_dma_intr--;
/* release if target did not response! */
falcon_release_lock_if_possible(hostdata);
break;
@@ -1093,7 +1093,7 @@ static void NCR5380_main(struct work_str
#ifdef SUPPORT_TAGS
cmd_free_tag(tmp);
#endif
- falcon_dont_release--;
+ hostdata->retain_dma_intr--;
local_irq_restore(flags);
dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
"returned to issue_queue\n", HOSTNO);
@@ -1150,7 +1150,7 @@ static void NCR5380_dma_complete(struct
return;
}

- if (atari_read_overruns) {
+ if (hostdata->read_overruns) {
p = hostdata->connected->SCp.phase;
if (p & SR_IO) {
udelay(10);
@@ -1180,9 +1180,9 @@ static void NCR5380_dma_complete(struct
*data += transfered;
*count -= transfered;

- if (atari_read_overruns) {
+ if (hostdata->read_overruns) {
if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
- cnt = toPIO = atari_read_overruns;
+ cnt = toPIO = hostdata->read_overruns;
if (overrun) {
dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
*(*data)++ = saved_data;
@@ -1837,8 +1837,8 @@ static int NCR5380_transfer_dma(struct S
return -1;
}

- if (atari_read_overruns && (p & SR_IO))
- c -= atari_read_overruns;
+ if (hostdata->read_overruns && (p & SR_IO))
+ c -= hostdata->read_overruns;

dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
HOSTNO, (p & SR_IO) ? "reading" : "writing",
@@ -1850,7 +1850,7 @@ static int NCR5380_transfer_dma(struct S
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
#endif /* def REAL_DMA */

- if (IS_A_TT()) {
+ if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
/* On the Medusa, it is a must to initialize the DMA before
* starting the NCR. This is also the cleaner way for the TT.
*/
@@ -1868,7 +1868,7 @@ static int NCR5380_transfer_dma(struct S
NCR5380_write(START_DMA_SEND_REG, 0);
}

- if (!IS_A_TT()) {
+ if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
/* On the Falcon, the DMA setup must be done after the last */
/* NCR access, else the DMA setup gets trashed!
*/
@@ -2083,7 +2083,7 @@ static void NCR5380_information_transfer
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/* ++guenther: possible race with Falcon locking */
- falcon_dont_release++;
+ hostdata->retain_dma_intr++;
hostdata->connected = NULL;
dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d, lun %d "
"completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
@@ -2166,7 +2166,7 @@ static void NCR5380_information_transfer
while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
barrier();

- falcon_dont_release--;
+ hostdata->retain_dma_intr--;
/* ++roman: For Falcon SCSI, release the lock on the
* ST-DMA here if no other commands are waiting on the
* disconnected queue.
@@ -2473,7 +2473,7 @@ static void NCR5380_reselect(struct Scsi
#endif
) {
/* ++guenther: prevent race with falcon_release_lock */
- falcon_dont_release++;
+ hostdata->retain_dma_intr++;
if (prev) {
REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
SET_NEXT(prev, NEXT(tmp));
@@ -2511,7 +2511,7 @@ static void NCR5380_reselect(struct Scsi
hostdata->connected = tmp;
dprintk(NDEBUG_RESELECTION, "scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
- falcon_dont_release--;
+ hostdata->retain_dma_intr--;
}