esp.c: rework esp_cdb_length() into esp_cdb_ready()

The esp_cdb_length() function is only used as part of a calculation to determine
whether the cmdfifo contains an entire SCSI CDB. Rework esp_cdb_length() into a
new esp_cdb_ready() function which both enables us to handle the case where
scsi_cdb_length() returns -1, plus simplify the logic for its callers.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20240324191707.623175-12-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
This commit is contained in:
Mark Cave-Ayland 2024-03-24 19:17:00 +00:00
parent 5a50644e47
commit 5aa0df4067

View File

@ -425,20 +425,20 @@ static void write_response(ESPState *s)
} }
} }
static int esp_cdb_length(ESPState *s) static bool esp_cdb_ready(ESPState *s)
{ {
int len = fifo8_num_used(&s->cmdfifo) - s->cmdfifo_cdb_offset;
const uint8_t *pbuf; const uint8_t *pbuf;
int cmdlen, len; int cdblen;
cmdlen = fifo8_num_used(&s->cmdfifo); if (len <= 0) {
if (cmdlen < s->cmdfifo_cdb_offset) { return false;
return 0;
} }
pbuf = fifo8_peek_buf(&s->cmdfifo, cmdlen, NULL); pbuf = fifo8_peek_buf(&s->cmdfifo, len, NULL);
len = scsi_cdb_length((uint8_t *)&pbuf[s->cmdfifo_cdb_offset]); cdblen = scsi_cdb_length((uint8_t *)&pbuf[s->cmdfifo_cdb_offset]);
return len; return cdblen < 0 ? false : (len >= cdblen);
} }
static void esp_dma_ti_check(ESPState *s) static void esp_dma_ti_check(ESPState *s)
@ -806,10 +806,9 @@ static void esp_do_nodma(ESPState *s)
trace_esp_handle_ti_cmd(cmdlen); trace_esp_handle_ti_cmd(cmdlen);
/* CDB may be transferred in one or more TI commands */ /* CDB may be transferred in one or more TI commands */
if (esp_cdb_length(s) && esp_cdb_length(s) == if (esp_cdb_ready(s)) {
fifo8_num_used(&s->cmdfifo) - s->cmdfifo_cdb_offset) { /* Command has been received */
/* Command has been received */ do_cmd(s);
do_cmd(s);
} else { } else {
/* /*
* If data was transferred from the FIFO then raise bus * If data was transferred from the FIFO then raise bus
@ -832,10 +831,9 @@ static void esp_do_nodma(ESPState *s)
fifo8_push_all(&s->cmdfifo, buf, len); fifo8_push_all(&s->cmdfifo, buf, len);
/* Handle when DMA transfer is terminated by non-DMA FIFO write */ /* Handle when DMA transfer is terminated by non-DMA FIFO write */
if (esp_cdb_length(s) && esp_cdb_length(s) == if (esp_cdb_ready(s)) {
fifo8_num_used(&s->cmdfifo) - s->cmdfifo_cdb_offset) { /* Command has been received */
/* Command has been received */ do_cmd(s);
do_cmd(s);
} }
break; break;