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esp: rework write_response() to avoid using the FIFO for DMA transactions

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The code for write_response() has always used the FIFO to store the data for
the status/message in phases, even for DMA transactions. Switch to using a
separate buffer that can be used directly for DMA transactions and restrict
the FIFO use to the non-DMA case.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210407195801.685-3-mark.cave-ayland@ilande.co.uk>
This commit is contained in:
Mark Cave-Ayland 2021-04-07 20:57:51 +01:00
parent 0db895361b
commit e392255766
1 changed files with 6 additions and 7 deletions
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13
hw/scsi/esp.c
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@ -445,18 +445,16 @@ static void write_response_pdma_cb(ESPState *s)
static void write_response(ESPState *s)
{
uint32_t n;
uint8_t buf[2];
trace_esp_write_response(s->status);
fifo8_reset(&s->fifo);
esp_fifo_push(s, s->status);
esp_fifo_push(s, 0);
buf[0] = s->status;
buf[1] = 0;
if (s->dma) {
if (s->dma_memory_write) {
s->dma_memory_write(s->dma_opaque,
(uint8_t *)fifo8_pop_buf(&s->fifo, 2, &n), 2);
s->dma_memory_write(s->dma_opaque, buf, 2);
s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
s->rregs[ESP_RSEQ] = SEQ_CD;
@ -466,7 +464,8 @@ static void write_response(ESPState *s)
return;
}
} else {
s->ti_size = 2;
fifo8_reset(&s->fifo);
fifo8_push_all(&s->fifo, buf, 2);
s->rregs[ESP_RFLAGS] = 2;
}
esp_raise_irq(s);