esp: introduce esp_get_tc() and esp_set_tc()

These functions simplify reading and writing the TC register value without having to
manually shift each individual 8-bit value.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-10-mark.cave-ayland@ilande.co.uk>

1 files changed, 23 insertions, 15 deletions

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 5365523..dd94f7b 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -98,6 +98,24 @@ void esp_request_cancelled(SCSIRequest *req)
     }
 }
 
+static uint32_t esp_get_tc(ESPState *s)
+{
+    uint32_t dmalen;
+
+    dmalen = s->rregs[ESP_TCLO];
+    dmalen |= s->rregs[ESP_TCMID] << 8;
+    dmalen |= s->rregs[ESP_TCHI] << 16;
+
+    return dmalen;
+}
+
+static void esp_set_tc(ESPState *s, uint32_t dmalen)
+{
+    s->rregs[ESP_TCLO] = dmalen;
+    s->rregs[ESP_TCMID] = dmalen >> 8;
+    s->rregs[ESP_TCHI] = dmalen >> 16;
+}
+
 static void set_pdma(ESPState *s, enum pdma_origin_id origin,
                      uint32_t index, uint32_t len)
 {
@@ -157,9 +175,7 @@ static uint32_t get_cmd(ESPState *s, uint8_t *buf, uint8_t buflen)
 
     target = s->wregs[ESP_WBUSID] & BUSID_DID;
     if (s->dma) {
-        dmalen = s->rregs[ESP_TCLO];
-        dmalen |= s->rregs[ESP_TCMID] << 8;
-        dmalen |= s->rregs[ESP_TCHI] << 16;
+        dmalen = esp_get_tc(s);
         if (dmalen > buflen) {
             return 0;
         }
@@ -348,9 +364,7 @@ static void esp_dma_done(ESPState *s)
     s->rregs[ESP_RINTR] = INTR_BS;
     s->rregs[ESP_RSEQ] = 0;
     s->rregs[ESP_RFLAGS] = 0;
-    s->rregs[ESP_TCLO] = 0;
-    s->rregs[ESP_TCMID] = 0;
-    s->rregs[ESP_TCHI] = 0;
+    esp_set_tc(s, 0);
     esp_raise_irq(s);
 }
 
@@ -535,9 +549,7 @@ static void handle_ti(ESPState *s)
         return;
     }
 
-    dmalen = s->rregs[ESP_TCLO];
-    dmalen |= s->rregs[ESP_TCMID] << 8;
-    dmalen |= s->rregs[ESP_TCHI] << 16;
+    dmalen = esp_get_tc(s);
     if (dmalen == 0) {
         dmalen = 0x10000;
     }
@@ -888,9 +900,7 @@ static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
 
     trace_esp_pdma_write(size);
 
-    dmalen = s->rregs[ESP_TCLO];
-    dmalen |= s->rregs[ESP_TCMID] << 8;
-    dmalen |= s->rregs[ESP_TCHI] << 16;
+    dmalen = esp_get_tc(s);
     if (dmalen == 0 || s->pdma_len == 0) {
         return;
     }
@@ -907,9 +917,7 @@ static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
         dmalen -= 2;
         break;
     }
-    s->rregs[ESP_TCLO] = dmalen & 0xff;
-    s->rregs[ESP_TCMID] = dmalen >> 8;
-    s->rregs[ESP_TCHI] = dmalen >> 16;
+    esp_set_tc(s, dmalen);
     if (s->pdma_len == 0 && s->pdma_cb) {
         esp_lower_drq(s);
         s->pdma_cb(s);