WIP: implement basic of alloc area

core/allocArea.c

@@ -0,0 +1,146 @@
+#include "allocArea.h"
+#include "alloc.h"
+#include "assert.h"
+#include "kernel.h"
+#include "list.h"
+#include "mem.h"
+#include "stdarg.h"
+
+struct memArea {
+    vaddr_t startAddr;
+    uint nbPages;
+    struct memArea *next;
+    struct memArea *prev;
+};
+
+static struct memArea *freeArea;
+static struct memArea *usedArea;
+
+void areaInit(void)
+{
+    list_init(freeArea);
+    list_init(usedArea);
+}
+
+struct memArea *areaFindFit(unsigned int nbPages)
+{
+    struct memArea *area;
+    int count;
+
+    list_foreach(freeArea, area, count)
+    {
+        if (area->nbPages >= nbPages)
+            return area;
+    }
+    return NULL;
+}
+
+static void insertSorted(struct memArea *list, struct memArea *item)
+{
+    struct memArea *prev, *cur;
+    int count;
+    prev = NULL;
+
+    list_foreach(list, cur, count)
+    {
+        if (cur->startAddr > item->startAddr)
+            break;
+        prev = cur;
+    }
+    if (prev)
+        list_insert_after(list, prev, item);
+    else
+        list_add_tail(list, item);
+}
+
+vaddr_t areaAlloc(unsigned int nbPages)
+{
+    struct memArea *area, *allocated;
+
+    area = areaFindFit(nbPages);
+    if (!area)
+        return (vaddr_t)NULL;
+
+    if (area->nbPages == nbPages) {
+        list_delete(freeArea, area);
+        insertSorted(usedArea, area);
+        allocated = area;
+    }
+
+    struct memArea *newArea = (struct memArea *)malloc(sizeof(struct memArea));
+    if (!newArea)
+        return (vaddr_t)NULL;
+
+    // Avoid insertSorted(freeArea, newArea) call by modifying area
+
+    newArea->nbPages   = nbPages;
+    newArea->startAddr = area->startAddr;
+
+    area->nbPages -= nbPages;
+    area->startAddr += nbPages * PAGE_SIZE;
+
+    insertSorted(usedArea, newArea);
+
+    allocated = newArea;
+
+    for (uint i = 0; i < nbPages; i++) {
+        paddr_t page = allocPhyPage(1);
+        if (page) {
+            pageMap(area->startAddr + i * PAGE_SIZE, page, PAGING_MEM_WRITE);
+        } else {
+            // TODO
+            assert(1);
+        }
+    }
+
+    return allocated->startAddr;
+}
+
+static int areaMergeFreeArea(struct memArea *prev, struct memArea *next)
+{
+    if (prev->startAddr + prev->nbPages * PAGE_SIZE != next->startAddr) {
+        return -1;
+    }
+
+    prev->nbPages += next->nbPages;
+    list_delete(freeArea, next);
+    free(next);
+
+    next = prev;
+
+    return 0;
+}
+
+static struct memArea *areaFindMemArea(struct memArea *list, vaddr_t addr)
+{
+    struct memArea *area;
+    int count;
+    list_foreach(list, area, count)
+    {
+        if (area->startAddr <= addr && addr <= area->startAddr + area->nbPages * PAGE_SIZE)
+            return area;
+    }
+
+    return NULL;
+}
+
+int areaFree(vaddr_t addr)
+{
+    struct memArea *area;
+
+    area = areaFindMemArea(usedArea, addr);
+    if (!area) {
+        pr_info("Cannot find memArea associated to %p\n", addr);
+        return -1;
+    }
+    list_delete(usedArea, area);
+    insertSorted(freeArea, area);
+
+    if (area->prev)
+        areaMergeFreeArea(area->prev, area);
+
+    if (area->next)
+        areaMergeFreeArea(area, area->next);
+
+    return 0;
+}

core/allocArea.h

@@ -0,0 +1,4 @@
+#pragma once
+#include "paging.h"
+
+void areaInit(void);