esp.c: consolidate DMA and PDMA logic in STATUS and MESSAGE IN phases

This allows the removal of duplicate logic shared between the two implementations.
Note that we restrict esp_raise_drq() to PDMA to help reduce the log verbosity
for normal DMA.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Helge Deller <deller@gmx.de>
Tested-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20240112125420.514425-83-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

hw/scsi/esp.c

@@ -593,12 +593,11 @@ static void esp_do_dma(ESPState *s)
 
                 if (s->dma_memory_write) {
                     s->dma_memory_write(s->dma_opaque, buf, len);
-                    esp_set_tc(s, esp_get_tc(s) - len);
                 } else {
                     fifo8_push_all(&s->fifo, buf, len);
-                    esp_set_tc(s, esp_get_tc(s) - len);
                 }
 
+                esp_set_tc(s, esp_get_tc(s) - len);
                 esp_set_phase(s, STAT_MI);
 
                 if (esp_get_tc(s) > 0) {
@@ -629,12 +628,12 @@ static void esp_do_dma(ESPState *s)
 
                 if (s->dma_memory_write) {
                     s->dma_memory_write(s->dma_opaque, buf, len);
-                    esp_set_tc(s, esp_get_tc(s) - len);
                 } else {
                     fifo8_push_all(&s->fifo, buf, len);
-                    esp_set_tc(s, esp_get_tc(s) - len);
                 }
 
+                esp_set_tc(s, esp_get_tc(s) - len);
+
                 /* Raise end of command interrupt */
                 s->rregs[ESP_RINTR] |= INTR_FC;
                 esp_raise_irq(s);