soc: descriptive part occupy whole component

components/soc/lldesc.c

@@ -0,0 +1,46 @@
+#include "soc/lldesc.h"
+
+void lldesc_setup_link(lldesc_t *dmadesc, const void *data, int len, bool isrx)
+{
+    int n = 0;
+    while (len) {
+        int dmachunklen = len;
+        if (dmachunklen > LLDESC_MAX_NUM_PER_DESC) {
+            dmachunklen = LLDESC_MAX_NUM_PER_DESC;
+        }
+        if (isrx) {
+            //Receive needs DMA length rounded to next 32-bit boundary
+            dmadesc[n].size = (dmachunklen + 3) & (~3);
+            dmadesc[n].length = (dmachunklen + 3) & (~3);
+        } else {
+            dmadesc[n].size = dmachunklen;
+            dmadesc[n].length = dmachunklen;
+        }
+        dmadesc[n].buf = (uint8_t *)data;
+        dmadesc[n].eof = 0;
+        dmadesc[n].sosf = 0;
+        dmadesc[n].owner = 1;
+        dmadesc[n].qe.stqe_next = &dmadesc[n + 1];
+        len -= dmachunklen;
+        data += dmachunklen;
+        n++;
+    }
+    dmadesc[n - 1].eof = 1; //Mark last DMA desc as end of stream.
+    dmadesc[n - 1].qe.stqe_next = NULL;
+}
+
+int lldesc_get_received_len(lldesc_t* head, lldesc_t** out_next)
+{
+    lldesc_t* desc = head;
+    int len = 0;
+    while(desc) {
+        len += desc->length;
+        bool eof = desc->eof;
+        desc = STAILQ_NEXT(desc, qe);
+        if (eof) break;
+    }
+    if (out_next) {
+        *out_next = desc;
+    }
+    return len;
+}