FIFO tagged functions

Co-Authored-By: Miran Grča <oubattler@gmail.com>

src/fifo.c

@@ -10,7 +10,7 @@
  *
  * Authors: Miran Grca, <mgrca8@gmail.com>
  *
- *          Copyright 2023 Miran Grca.
+ *          Copyright 2023-2025 Miran Grca.
  */
 #include <stdarg.h>
 #include <stdint.h>
@@ -84,6 +84,31 @@ fifo_write(uint8_t val, void *priv)
     }
 }
 
+void
+fifo_write_tagged(uint8_t tag, uint8_t val, void *priv)
+{
+    fifo_t *fifo = (fifo_t *) priv;
+
+    fifo->d_full  = fifo->d_empty = 0;
+    fifo->d_ready = fifo->d_overrun = 0;
+
+    if (fifo->full)
+        fifo->overrun = 1;
+    else {
+        fifo->buf[fifo->end] = val;
+        fifo->tag[fifo->end] = tag;
+        fifo->end            = (fifo->end + 1) % fifo->len;
+
+        if (fifo->end == fifo->start)
+            fifo->full = 1;
+
+        fifo->empty = 0;
+
+        if (fifo_get_count(fifo) >= fifo->trigger_len)
+            fifo->ready = 1;
+    }
+}
+
 void
 fifo_write_evt(uint8_t val, void *priv)
 {
@@ -122,6 +147,45 @@ fifo_write_evt(uint8_t val, void *priv)
     }
 }
 
+void
+fifo_write_evt_tagged(uint8_t tag, uint8_t val, void *priv)
+{
+    fifo_t *fifo = (fifo_t *) priv;
+
+    fifo->d_full  = fifo->d_empty = 0;
+    fifo->d_ready = fifo->d_overrun = 0;
+
+    if (fifo->full) {
+        fifo->d_overrun = (fifo->overrun != 1);
+        fifo->overrun   = 1;
+        if (fifo->d_overrun && (fifo->d_overrun_evt != NULL))
+            fifo->d_overrun_evt(fifo->priv);
+    } else {
+        fifo->buf[fifo->end] = val;
+        fifo->tag[fifo->end] = tag;
+        fifo->end            = (fifo->end + 1) % fifo->len;
+
+        if (fifo->end == fifo->start) {
+            fifo->d_full = (fifo->full != 1);
+            fifo->full   = 1;
+            if (fifo->d_full && (fifo->d_full_evt != NULL))
+                fifo->d_full_evt(fifo->priv);
+        }
+
+        fifo->d_empty = (fifo->empty != 0);
+        fifo->empty = 0;
+        if (fifo->d_empty && (fifo->d_empty_evt != NULL))
+            fifo->d_empty_evt(fifo->priv);
+
+        if (fifo_get_count(fifo) >= fifo->trigger_len) {
+            fifo->d_ready = (fifo->ready != 1);
+            fifo->ready   = 1;
+            if (fifo->d_ready && (fifo->d_ready_evt != NULL))
+                fifo->d_ready_evt(fifo->priv);
+        }
+    }
+}
+
 uint8_t
 fifo_read(void *priv)
 {
@@ -148,6 +212,35 @@ fifo_read(void *priv)
     return ret;
 }
 
+uint8_t
+fifo_read_tagged(uint8_t *tag, void *priv)
+{
+    fifo_t *fifo = (fifo_t *) priv;
+    uint8_t ret  = 0x00;
+    int     count;
+
+    if (!fifo->empty) {
+        ret         = fifo->buf[fifo->start];
+        *tag        = fifo->tag[fifo->start];
+
+        fifo->start = (fifo->start + 1) % fifo->len;
+
+        fifo->full = 0;
+
+        count = fifo_get_count(fifo);
+
+        if (count < fifo->trigger_len) {
+            fifo->ready = 0;
+
+            if (count == 0)
+                fifo->empty = 1;
+        }
+    } else
+        *tag        = 0x00;
+
+    return ret;
+}
+
 uint8_t
 fifo_read_evt(void *priv)
 {
@@ -187,6 +280,48 @@ fifo_read_evt(void *priv)
     return ret;
 }
 
+uint8_t
+fifo_read_evt_tagged(uint8_t *tag, void *priv)
+{
+    fifo_t *fifo = (fifo_t *) priv;
+    uint8_t ret = 0x00;
+    int     count;
+
+    fifo->d_full = fifo->d_empty = 0;
+    fifo->d_ready = 0;
+
+    if (!fifo->empty) {
+        ret         = fifo->buf[fifo->start];
+        *tag        = fifo->tag[fifo->start];
+
+        fifo->start = (fifo->start + 1) % fifo->len;
+
+        fifo->d_full = (fifo->full != 0);
+        fifo->full   = 0;
+        if (fifo->d_full && (fifo->d_full_evt != NULL))
+            fifo->d_full_evt(fifo->priv);
+
+        count = fifo_get_count(fifo);
+
+        if (count < fifo->trigger_len) {
+            fifo->d_ready = (fifo->ready != 0);
+            fifo->ready   = 0;
+            if (fifo->d_ready && (fifo->d_ready_evt != NULL))
+                fifo->d_ready_evt(fifo->priv);
+
+            if (count == 0) {
+                fifo->d_empty = (fifo->empty != 1);
+                fifo->empty   = 1;
+                if (fifo->d_empty && (fifo->d_empty_evt != NULL))
+                    fifo->d_empty_evt(fifo->priv);
+            }
+        }
+    } else
+        *tag        = 0x00;
+
+    return ret;
+}
+
 void
 fifo_clear_overrun(void *priv)
 {

src/include/86box/fifo.h

@@ -1,6 +1,3 @@
-#ifndef FIFO_H
-#define FIFO_H
-
 /*
  * 86Box    A hypervisor and IBM PC system emulator that specializes in
  *          running old operating systems and software designed for IBM
@@ -13,8 +10,11 @@
  *
  * Authors: Miran Grca, <mgrca8@gmail.com>
  *
- *          Copyright 2023 Miran Grca.
+ *          Copyright 2023-2025 Miran Grca.
  */
+#ifndef FIFO_H
+#define FIFO_H
+
 #define FIFO(size)                      \
     typedef struct {                    \
         int     start;                  \
@@ -37,6 +37,7 @@
         void  (*d_full_evt)(void *);    \
         void  (*d_ready_evt)(void *);   \
                                         \
+        uint8_t tag[64];                \
         uint8_t buf[size];              \
     } fifo## size ##_t;
 
@@ -50,9 +51,13 @@ FIFO(64)
 
 extern int        fifo_get_count(void *priv);
 extern void       fifo_write(uint8_t val, void *priv);
+extern void       fifo_write_tagged(uint8_t tag, uint8_t val, void *priv);
 extern void       fifo_write_evt(uint8_t val, void *priv);
+extern void       fifo_write_evt_tagged(uint8_t tag, uint8_t val, void *priv);
 extern uint8_t    fifo_read(void *priv);
+extern uint8_t    fifo_read_tagged(uint8_t *tag, void *priv);
 extern uint8_t    fifo_read_evt(void *priv);
+extern uint8_t    fifo_read_evt_tagged(uint8_t *tag, void *priv);
 extern void       fifo_clear_overrun(void *priv);
 extern int        fifo_get_full(void *priv);
 extern int        fifo_get_d_full(void *priv);