From e1e00c951b4c87584c144f6077737314f50a714a Mon Sep 17 00:00:00 2001
From: joevt <joevt@shaw.ca>
Date: Sun, 10 Mar 2024 21:10:40 -0700
Subject: [PATCH] sc53c94: Split real_dma_xfer.

Create real_dma_xfer_out and real_dma_xfer_in methods.
---
 devices/common/scsi/sc53c94.cpp | 59 +++++++++++++++++----------------
 devices/common/scsi/sc53c94.h   |  3 +-
 devices/ioctrl/amic.cpp         |  5 ++-
 3 files changed, 37 insertions(+), 30 deletions(-)

diff --git a/devices/common/scsi/sc53c94.cpp b/devices/common/scsi/sc53c94.cpp
index 07dbac0..e883cd5 100644
--- a/devices/common/scsi/sc53c94.cpp
+++ b/devices/common/scsi/sc53c94.cpp
@@ -632,20 +632,38 @@ bool Sc53C94::rcv_data()
     return true;
 }
 
-void Sc53C94::real_dma_xfer(int direction)
+void Sc53C94::real_dma_xfer_out()
+{
+    // transfer data from host's memory to target
+
+    while (this->xfer_count) {
+        uint32_t got_bytes;
+        uint8_t* src_ptr;
+        this->dma_ch->pull_data(std::min((int)this->xfer_count, DATA_FIFO_MAX),
+                                &got_bytes, &src_ptr);
+        std::memcpy(this->data_fifo, src_ptr, got_bytes);
+        this->data_fifo_pos = got_bytes;
+        this->bus_obj->push_data(this->target_id, this->data_fifo, this->data_fifo_pos);
+
+        this->xfer_count -= this->data_fifo_pos;
+        this->data_fifo_pos = 0;
+        if (!this->xfer_count) {
+            this->status |= STAT_TC; // signal zero transfer count
+            this->cur_state = SeqState::XFER_END;
+            this->sequencer();
+        }
+    }
+}
+
+void Sc53C94::real_dma_xfer_in()
 {
     bool is_done = false;
 
-    if (direction) {
-        uint32_t got_bytes;
-        uint8_t* src_ptr;
+    // transfer data from target to host's memory
 
-        while (this->xfer_count) {
-            this->dma_ch->pull_data(std::min((int)this->xfer_count, DATA_FIFO_MAX),
-                                    &got_bytes, &src_ptr);
-            std::memcpy(this->data_fifo, src_ptr, got_bytes);
-            this->data_fifo_pos = got_bytes;
-            this->bus_obj->push_data(this->target_id, this->data_fifo, this->data_fifo_pos);
+    while (this->xfer_count) {
+        if (this->data_fifo_pos) {
+            this->dma_ch->push_data((char*)this->data_fifo, this->data_fifo_pos);
 
             this->xfer_count -= this->data_fifo_pos;
             this->data_fifo_pos = 0;
@@ -656,25 +674,10 @@ void Sc53C94::real_dma_xfer(int direction)
                 this->sequencer();
             }
         }
-    } else { // transfer data from target to host's memory
-        while (this->xfer_count) {
-            if (this->data_fifo_pos) {
-                this->dma_ch->push_data((char*)this->data_fifo, this->data_fifo_pos);
 
-                this->xfer_count -= this->data_fifo_pos;
-                this->data_fifo_pos = 0;
-                if (!this->xfer_count) {
-                    is_done = true;
-                    this->status |= STAT_TC; // signal zero transfer count
-                    this->cur_state = SeqState::XFER_END;
-                    this->sequencer();
-                }
-            }
-
-            // see if we need to refill FIFO
-            if (!this->data_fifo_pos && !is_done) {
-                this->sequencer();
-            }
+        // see if we need to refill FIFO
+        if (!this->data_fifo_pos && !is_done) {
+            this->sequencer();
         }
     }
 }
diff --git a/devices/common/scsi/sc53c94.h b/devices/common/scsi/sc53c94.h
index 2711baa..da4ab80 100644
--- a/devices/common/scsi/sc53c94.h
+++ b/devices/common/scsi/sc53c94.h
@@ -207,7 +207,8 @@ public:
     void     pseudo_dma_write(uint16_t data);
 
     // real DMA control
-    void     real_dma_xfer(int direction);
+    void real_dma_xfer_out();
+    void real_dma_xfer_in();
 
     void set_dma_channel(DmaBidirChannel *dma_ch) {
         this->dma_ch = dma_ch;
diff --git a/devices/ioctrl/amic.cpp b/devices/ioctrl/amic.cpp
index 11f689b..d8a9882 100644
--- a/devices/ioctrl/amic.cpp
+++ b/devices/ioctrl/amic.cpp
@@ -384,7 +384,10 @@ void AMIC::write(uint32_t rgn_start, uint32_t offset, uint32_t value, int size)
         }
         if (value & 2) { // RUN bit set?
             this->curio_dma->reinit(this->scsi_dma_base);
-            this->scsi->real_dma_xfer((value >> 6) & 1);
+            if (value & (1 << 6))
+                this->scsi->real_dma_xfer_out();
+            else
+                this->scsi->real_dma_xfer_in();
         }
         this->curio_dma->write_ctrl(value);
         break;