Currently any write to the ESP FIFO in the MESSAGE OUT or COMMAND phases will
manually raise the bus service interrupt. Instead of duplicating the interrupt
logic in esp_reg_write(), update esp_do_nodma() to correctly process incoming
FIFO data during the MESSAGE OUT and COMMAND phases. Part of this change is to
call esp_nodma_ti_dataout() from handle_ti() to ensure that the DATA OUT phase
FIFO transfer only occurs when executing a non-DMA TI command instead of for
each byte entering the FIFO.
One slight complication is that NextSTEP uses multiple TI commands to transfer
the CDB one byte at a time (as opposed to loading the FIFO and using a single
TI command), so it is necessary to determine the expected length of the SCSI
CDB being received. This is handled by the introduction of a new
esp_cdb_length() function which returns the expected SCSI CDB length based
upon the first command byte.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
hw/scsi/esp.c | 121 +++++++++++++++++++++++++++++++++++---------------
1 file changed, 86 insertions(+), 35 deletions(-)
diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 97e48e9526..5bb8cc4ea7 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -420,6 +420,7 @@ static void handle_satn_stop(ESPState *s)
esp_set_phase(s, STAT_MO);
s->rregs[ESP_RSEQ] = SEQ_MO;
+ s->cmdfifo_cdb_offset = 0;
if (s->dma) {
esp_do_dma(s);
@@ -454,6 +455,22 @@ static void write_response(ESPState *s)
}
}
+static int esp_cdb_length(ESPState *s)
+{
+ const uint8_t *pbuf;
+ int cmdlen, len;
+
+ cmdlen = fifo8_num_used(&s->cmdfifo);
+ if (cmdlen < s->cmdfifo_cdb_offset) {
+ return 0;
+ }
+
+ pbuf = fifo8_peek_buf(&s->cmdfifo, cmdlen, NULL);
+ len = scsi_cdb_length((uint8_t *)&pbuf[s->cmdfifo_cdb_offset]);
+
+ return len;
+}
+
static void esp_dma_ti_check(ESPState *s)
{
if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
@@ -738,16 +755,40 @@ static void esp_do_nodma(ESPState *s)
fifo8_push_all(&s->cmdfifo, buf, n);
s->cmdfifo_cdb_offset += n;
- /*
- * Extra message out bytes received: update cmdfifo_cdb_offset
- * and then switch to command phase
- */
- s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
- esp_set_phase(s, STAT_CD);
- s->rregs[ESP_CMD] = 0;
- s->rregs[ESP_RSEQ] = SEQ_CD;
- s->rregs[ESP_RINTR] |= INTR_BS;
- esp_raise_irq(s);
+ switch (s->rregs[ESP_CMD]) {
+ case CMD_SELATN:
+ if (fifo8_num_used(&s->cmdfifo) >= 1) {
+ /* First byte received, switch to command phase */
+ esp_set_phase(s, STAT_CD);
+ s->cmdfifo_cdb_offset = 1;
+
+ if (fifo8_num_used(&s->cmdfifo) > 1) {
+ /* Process any additional command phase data */
+ esp_do_nodma(s);
+ }
+ }
+ break;
+
+ case CMD_SELATNS:
+ if (fifo8_num_used(&s->cmdfifo) == 1) {
+ /* First byte received, stop in message out phase */
+ s->cmdfifo_cdb_offset = 1;
+
+ /* Raise command completion interrupt */
+ s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
+ esp_raise_irq(s);
+ }
+ break;
+
+ case CMD_TI:
+ /* ATN remains asserted until FIFO empty */
+ s->cmdfifo_cdb_offset = fifo8_num_used(&s->cmdfifo);
+ esp_set_phase(s, STAT_CD);
+ s->rregs[ESP_CMD] = 0;
+ s->rregs[ESP_RINTR] |= INTR_BS;
+ esp_raise_irq(s);
+ break;
+ }
break;
case STAT_CD:
@@ -756,21 +797,40 @@ static void esp_do_nodma(ESPState *s)
n = MIN(fifo8_num_free(&s->cmdfifo), n);
fifo8_push_all(&s->cmdfifo, buf, n);
- cmdlen = fifo8_num_used(&s->cmdfifo);
- trace_esp_handle_ti_cmd(cmdlen);
- s->ti_size = 0;
+ switch (s->rregs[ESP_CMD]) {
+ case CMD_TI:
+ cmdlen = fifo8_num_used(&s->cmdfifo);
+ trace_esp_handle_ti_cmd(cmdlen);
+
+ /* CDB may be transferred in one or more TI commands */
+ if (esp_cdb_length(s) && esp_cdb_length(s) ==
+ fifo8_num_used(&s->cmdfifo) - s->cmdfifo_cdb_offset) {
+ /* Command has been received */
+ do_cmd(s);
+ } else {
+ /*
+ * If data was transferred from the FIFO then raise bus
+ * service interrupt to indicate transfer complete. Otherwise
+ * defer until the next FIFO write.
+ */
+ if (n) {
+ /* Raise interrupt to indicate transfer complete */
+ s->rregs[ESP_RINTR] |= INTR_BS;
+ esp_raise_irq(s);
+ }
+ }
+ break;
- /* No command received */
- if (s->cmdfifo_cdb_offset == fifo8_num_used(&s->cmdfifo)) {
- return;
+ case CMD_SEL:
+ case CMD_SELATN:
+ /* FIFO already contain entire CDB */
+ do_cmd(s);
+ break;
}
-
- /* Command has been received */
- do_cmd(s);
break;
case STAT_DO:
- esp_nodma_ti_dataout(s);
+ /* Accumulate data in FIFO until non-DMA TI is executed */
break;
case STAT_DI:
@@ -945,6 +1005,10 @@ static void handle_ti(ESPState *s)
} else {
trace_esp_handle_ti(s->ti_size);
esp_do_nodma(s);
+
+ if (esp_get_phase(s) == STAT_DO) {
+ esp_nodma_ti_dataout(s);
+ }
}
}
@@ -1141,23 +1205,10 @@ void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val)
s->rregs[ESP_RSTAT] &= ~STAT_TC;
break;
case ESP_FIFO:
- if (esp_get_phase(s) == STAT_MO || esp_get_phase(s) == STAT_CD) {
- if (!fifo8_is_full(&s->fifo)) {
- esp_fifo_push(&s->fifo, val);
- esp_fifo_push(&s->cmdfifo, fifo8_pop(&s->fifo));
- }
-
- /*
- * If any unexpected message out/command phase data is
- * transferred using non-DMA, raise the interrupt
- */
- if (s->rregs[ESP_CMD] == CMD_TI) {
- s->rregs[ESP_RINTR] |= INTR_BS;
- esp_raise_irq(s);
- }
- } else {
+ if (!fifo8_is_full(&s->fifo)) {
esp_fifo_push(&s->fifo, val);
}
+ esp_do_nodma(s);
break;
case ESP_CMD:
s->rregs[saddr] = val;
--
2.39.2