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path: root/drivers/scsi/mac_scsi.c
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Diffstat (limited to 'drivers/scsi/mac_scsi.c')
-rw-r--r--drivers/scsi/mac_scsi.c170
1 files changed, 88 insertions, 82 deletions
diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c
index 53ee8f84d094..f225bb20aa22 100644
--- a/drivers/scsi/mac_scsi.c
+++ b/drivers/scsi/mac_scsi.c
@@ -102,11 +102,15 @@ __setup("mac5380=", mac_scsi_setup);
* Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets
* so bus errors are unavoidable.
*
- * If a MOVE.B instruction faults, we assume that zero bytes were transferred
- * and simply retry. That assumption probably depends on target behaviour but
- * seems to hold up okay. The NOP provides synchronization: without it the
- * fault can sometimes occur after the program counter has moved past the
- * offending instruction. Post-increment addressing can't be used.
+ * If a MOVE.B instruction faults during a receive operation, we assume the
+ * target sent nothing and try again. That assumption probably depends on
+ * target firmware but it seems to hold up okay. If a fault happens during a
+ * send operation, the target may or may not have seen /ACK and got the byte.
+ * It's uncertain so the whole SCSI command gets retried.
+ *
+ * The NOP is needed for synchronization because the fault address in the
+ * exception stack frame may or may not be the instruction that actually
+ * caused the bus error. Post-increment addressing can't be used.
*/
#define MOVE_BYTE(operands) \
@@ -208,8 +212,6 @@ __setup("mac5380=", mac_scsi_setup);
".previous \n" \
: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
-#define MAC_PDMA_DELAY 32
-
static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
{
unsigned char *addr = start;
@@ -245,22 +247,21 @@ static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
if (n >= 1) {
MOVE_BYTE("%0@,%3@");
if (result)
- goto out;
+ return -1;
}
if (n >= 1 && ((unsigned long)addr & 1)) {
MOVE_BYTE("%0@,%3@");
if (result)
- goto out;
+ return -2;
}
while (n >= 32)
MOVE_16_WORDS("%0@+,%3@");
while (n >= 2)
MOVE_WORD("%0@+,%3@");
if (result)
- return start - addr; /* Negated to indicate uncertain length */
+ return start - addr - 1; /* Negated to indicate uncertain length */
if (n == 1)
MOVE_BYTE("%0@,%3@");
-out:
return addr - start;
}
@@ -274,25 +275,56 @@ static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
out_be32(hostdata->io + (CTRL_REG << 4), value);
}
+static inline int macscsi_wait_for_drq(struct NCR5380_hostdata *hostdata)
+{
+ unsigned int n = 1; /* effectively multiplies NCR5380_REG_POLL_TIME */
+ unsigned char basr;
+
+again:
+ basr = NCR5380_read(BUS_AND_STATUS_REG);
+
+ if (!(basr & BASR_PHASE_MATCH))
+ return 1;
+
+ if (basr & BASR_IRQ)
+ return -1;
+
+ if (basr & BASR_DRQ)
+ return 0;
+
+ if (n-- == 0) {
+ NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
+ dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
+ "%s: DRQ timeout\n", __func__);
+ return -1;
+ }
+
+ NCR5380_poll_politely2(hostdata,
+ BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
+ BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0);
+ goto again;
+}
+
static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
unsigned char *dst, int len)
{
u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
unsigned char *d = dst;
- int result = 0;
hostdata->pdma_residual = len;
- while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
- BASR_DRQ | BASR_PHASE_MATCH,
- BASR_DRQ | BASR_PHASE_MATCH, 0)) {
- int bytes;
+ while (macscsi_wait_for_drq(hostdata) == 0) {
+ int bytes, chunk_bytes;
if (macintosh_config->ident == MAC_MODEL_IIFX)
write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
CTRL_INTERRUPTS_ENABLE);
- bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512));
+ chunk_bytes = min(hostdata->pdma_residual, 512);
+ bytes = mac_pdma_recv(s, d, chunk_bytes);
+
+ if (macintosh_config->ident == MAC_MODEL_IIFX)
+ write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
if (bytes > 0) {
d += bytes;
@@ -300,37 +332,25 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
}
if (hostdata->pdma_residual == 0)
- goto out;
+ break;
- if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
- BUS_AND_STATUS_REG, BASR_ACK,
- BASR_ACK, 0) < 0)
- scmd_printk(KERN_DEBUG, hostdata->connected,
- "%s: !REQ and !ACK\n", __func__);
- if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
- goto out;
+ if (bytes > 0)
+ continue;
- if (bytes == 0)
- udelay(MAC_PDMA_DELAY);
+ NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
+ dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
+ "%s: bus error [%d/%d] (%d/%d)\n",
+ __func__, d - dst, len, bytes, chunk_bytes);
- if (bytes >= 0)
+ if (bytes == 0)
continue;
- dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
- "%s: bus error (%d/%d)\n", __func__, d - dst, len);
- NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
- result = -1;
- goto out;
+ if (macscsi_wait_for_drq(hostdata) <= 0)
+ set_host_byte(hostdata->connected, DID_ERROR);
+ break;
}
- scmd_printk(KERN_ERR, hostdata->connected,
- "%s: phase mismatch or !DRQ\n", __func__);
- NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
- result = -1;
-out:
- if (macintosh_config->ident == MAC_MODEL_IIFX)
- write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
- return result;
+ return 0;
}
static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
@@ -338,67 +358,47 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
{
unsigned char *s = src;
u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
- int result = 0;
hostdata->pdma_residual = len;
- while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
- BASR_DRQ | BASR_PHASE_MATCH,
- BASR_DRQ | BASR_PHASE_MATCH, 0)) {
- int bytes;
+ while (macscsi_wait_for_drq(hostdata) == 0) {
+ int bytes, chunk_bytes;
if (macintosh_config->ident == MAC_MODEL_IIFX)
write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
CTRL_INTERRUPTS_ENABLE);
- bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512));
+ chunk_bytes = min(hostdata->pdma_residual, 512);
+ bytes = mac_pdma_send(s, d, chunk_bytes);
+
+ if (macintosh_config->ident == MAC_MODEL_IIFX)
+ write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
if (bytes > 0) {
s += bytes;
hostdata->pdma_residual -= bytes;
}
- if (hostdata->pdma_residual == 0) {
- if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
- TCR_LAST_BYTE_SENT,
- TCR_LAST_BYTE_SENT,
- 0) < 0) {
- scmd_printk(KERN_ERR, hostdata->connected,
- "%s: Last Byte Sent timeout\n", __func__);
- result = -1;
- }
- goto out;
- }
+ if (hostdata->pdma_residual == 0)
+ break;
- if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
- BUS_AND_STATUS_REG, BASR_ACK,
- BASR_ACK, 0) < 0)
- scmd_printk(KERN_DEBUG, hostdata->connected,
- "%s: !REQ and !ACK\n", __func__);
- if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
- goto out;
+ if (bytes > 0)
+ continue;
- if (bytes == 0)
- udelay(MAC_PDMA_DELAY);
+ NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
+ dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
+ "%s: bus error [%d/%d] (%d/%d)\n",
+ __func__, s - src, len, bytes, chunk_bytes);
- if (bytes >= 0)
+ if (bytes == 0)
continue;
- dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
- "%s: bus error (%d/%d)\n", __func__, s - src, len);
- NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
- result = -1;
- goto out;
+ if (macscsi_wait_for_drq(hostdata) <= 0)
+ set_host_byte(hostdata->connected, DID_ERROR);
+ break;
}
- scmd_printk(KERN_ERR, hostdata->connected,
- "%s: phase mismatch or !DRQ\n", __func__);
- NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
- result = -1;
-out:
- if (macintosh_config->ident == MAC_MODEL_IIFX)
- write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
- return result;
+ return 0;
}
static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
@@ -432,7 +432,7 @@ static struct scsi_host_template mac_scsi_template = {
.eh_host_reset_handler = macscsi_host_reset,
.can_queue = 16,
.this_id = 7,
- .sg_tablesize = 1,
+ .sg_tablesize = SG_ALL,
.cmd_per_lun = 2,
.dma_boundary = PAGE_SIZE - 1,
.cmd_size = sizeof(struct NCR5380_cmd),
@@ -470,6 +470,9 @@ static int __init mac_scsi_probe(struct platform_device *pdev)
if (setup_hostid >= 0)
mac_scsi_template.this_id = setup_hostid & 7;
+ if (macintosh_config->ident == MAC_MODEL_IIFX)
+ mac_scsi_template.sg_tablesize = 1;
+
instance = scsi_host_alloc(&mac_scsi_template,
sizeof(struct NCR5380_hostdata));
if (!instance)
@@ -491,6 +494,9 @@ static int __init mac_scsi_probe(struct platform_device *pdev)
host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
+ if (instance->sg_tablesize > 1)
+ host_flags |= FLAG_DMA_FIXUP;
+
error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
if (error)
goto fail_init;
generated by cgit (git 2.34.1) at 2025-05-02 01:27:05 +0000