Kernel page allocator and heap use new algorithms

include/heap.h

@@ -8,13 +8,11 @@
  * This function contructs the heap's internal tables, allocating pages as needed
  * to do so.
  * 
- * @param page_stack Pointer to the page stack descriptor
  * @param base Base location of the heap to contruct
  * @param heap_size Total size in bytes of the heap
- * @param block_size Size in bytes of a single unit of allocation
  * @return a status code
  */
-int kminit(void *base, void* start, size_t heap_size, size_t block_size);
+int kminit(void *base, size_t heap_size);
 
 /**
  * @brief Allocates a block of memory containing at least `size` bytes.

src/heap.c

@@ -1,34 +1,24 @@
 #include <stdbool.h>
-#include <libmalloc/bitmap_alloc.h>
+#include <libmalloc/list_alloc.h>
 #include "heap.h"
 #include "mmgr.h"
 #include "math.h"
 #include "stdio.h"
 #include "types/status.h"
 
-bitmap_heap_descriptor_t system_heap;
+list_alloc_descriptor_t system_heap;
-
-static int map_block(void *location, unsigned long size)
-{
-    for(int n = 0; n < size; n += page_size)
-    {
-        if(!(page_type(location + n) & PAGE_PRESENT))
-        {
-            int status = map_page(location + n, reserve_page(), PAGE_RW);
-            if(status)
-            {
-                return status;
-            }
-        }
-    }
-    return ENONE;
-}
 
 static int mmap_callback(void *location, unsigned long size)
 {
+    size += (unsigned long)location % page_size;
+    location -= (unsigned long)location % page_size;
     int status = ENONE;
     for(unsigned long i = 0; i < size; i += page_size)
     {
+        if((page_type(location + i) & PAGE_PRESENT))
+        {
+            continue;
+        }
         physaddr_t frame = reserve_page();
         if(frame == ENOMEM)
         {
@@ -42,44 +32,44 @@ static int mmap_callback(void *location, unsigned long size)
     return status;
 }
 
-int kminit(void *base, void* start, size_t heap_size, size_t block_size)
+int kminit(void *base, size_t heap_size)
 {
-    static unsigned long heap_cache[16];
-    system_heap.bitmap = NULL;
-    system_heap.cache = heap_cache;
-    system_heap.cache_capacity = 16;
-    system_heap.block_bits = 4;
-    system_heap.block_size = block_size;
-    system_heap.offset = (unsigned long)base;
     memory_region_t map_array[8];
     memory_map_t map = {
         .array = map_array,
         .capacity = 8,
         .size = 0
     };
-    memmap_insert_region(&map, 0, heap_size, M_AVAILABLE);
+    memmap_insert_region(&map, base, heap_size, M_AVAILABLE);
-    memmap_insert_region(&map, 0, start - base, M_UNAVAILABLE);
+    for(void *p = base; p < (base + heap_size); p += page_size)
-    return initialize_heap(&system_heap, &map, mmap_callback);
+    {
+        if((page_type(p) & PAGE_PRESENT))
+        {
+            continue;
+        }
+        physaddr_t frame = reserve_page();
+        if(frame == ENOMEM || map_page(p, frame, PAGE_RW))
+        {
+            return ENOMEM;
+        }
+    }
+    return list_alloc_init(&system_heap, &map);
 }
 
 void *kmalloc(size_t size)
 {
-    unsigned long loc = reserve_region(&system_heap, size);
+    void *p = list_alloc_reserve(&system_heap, size);
-    if(loc == NOMEM)
+    if(p == NOMEM)
-    {
-        return NULL;
-    }
-    else if(map_block((void*)loc, size))
     {
         return NULL;
     }
     else
     {
-        return (void*)loc;
+        return p;
     }
 }
 
 void kfree(void *ptr)
 {
-    free_region(&system_heap, (unsigned long)ptr, 0);
+    list_alloc_free(&system_heap, (unsigned long)ptr);
 }

src/kernel.c

@@ -41,7 +41,9 @@ void kernel_initialize(struct boot_info_t *boot_info)
         panic("Failed to initialize page allocator.");
     }
 
-    if(kminit(&_kernel_start, page_map_end(), 0xFFC00000 - (size_t)&_kernel_start, 64))
+    printf("End of page map: %08x\n", page_map_end);
+
+    if(kminit(page_map_end(), 0xFFC00000 - (size_t)page_map_end()))
     {
         panic("Failed to initialize heap.");
     }

src/mmgr.c

@@ -4,17 +4,17 @@
 #include "platform/paging.h"
 #include "types/status.h"
 #include "stdio.h"
-#include <libmalloc/bitmap_alloc.h>
+#include <libmalloc/buddy_alloc.h>
 #include <stdint.h>
 #include <stdbool.h>
 
-#define MAX_CACHE_SIZE 32
+#define AVAIL_LIST_SIZE 20
 
-bitmap_heap_descriptor_t page_map;
+buddy_descriptor_t page_alloc;
 
 physaddr_t reserve_pages(size_t size)
 {
-    unsigned long location = reserve_region(&page_map, size);
+    unsigned long location = buddy_reserve(&page_alloc, size);
     if(location != NOMEM)
     {
         return location;
@@ -27,61 +27,60 @@ physaddr_t reserve_pages(size_t size)
 
 int free_pages(physaddr_t location, size_t size)
 {
-    free_region(&page_map, location, size);
+    buddy_free_size(&page_alloc, location, size);
     return ENONE;
 }
 
 physaddr_t reserve_page()
 {
-    unsigned long loc = reserve_region(&page_map, page_size);
+    unsigned long loc = buddy_reserve(&page_alloc, page_size);
+    printf("Reserved %08x\n", loc);
     if(loc == NOMEM)
     {
         return ENOMEM;
     }
     else
     {
-        printf("Reserved %08x\n", loc);
         return loc;
     }
 }
 
 int free_page(physaddr_t location)
 {
-    free_region(&page_map, location, page_size);
+    buddy_free_size(&page_alloc, location, page_size);
     return ENONE;
 }
 
 size_t free_page_count()
 {
-    return page_map.free_block_count;
+    return page_alloc.free_block_count;
 }
 
 void *page_map_base()
 {
-    return (void*)page_map.bitmap;
+    return (void*)page_alloc.block_map;
 }
 
 void *page_map_end()
 {
-    return (void*)page_map.bitmap + page_map.bitmap_size;
+    return (void*)page_alloc.block_map + page_alloc.block_map_size;
 }
 
 error_t initialize_page_map(memory_map_t *map, void *base, size_t memory_size, unsigned long block_size)
 {
-    static unsigned long page_map_cache[MAX_CACHE_SIZE];
+    static unsigned long avail_list[AVAIL_LIST_SIZE];
     // Round memory_size up to nearest power of 2
     memory_size = 1 << llog2(memory_size);
 
-    page_map.block_size = block_size;
+    page_alloc.avail = avail_list;
-    page_map.block_bits = 1;
+    page_alloc.block_map = (buddy_block_t*) base;
-    page_map.offset = 0;
+    page_alloc.block_size = block_size;
-    page_map.cache = page_map_cache;
+    page_alloc.mmap = NULL;
-    page_map.cache_capacity = MAX_CACHE_SIZE;
+    page_alloc.offset = 0;
-    page_map.bitmap = (unsigned long*) base;
 
     /* Allocate pages for bitmap */
     int pages_mapped = 0;
-    int pages_needed = (bitmap_size(map, block_size, 1) + page_size - 1) / page_size;
+    int pages_needed = (buddy_map_size(map, block_size) + page_size - 1) / page_size;
     for(int i = 0; i < map->size && (pages_mapped < pages_needed); i++)
     {
         if(map->array[i].type != M_AVAILABLE)
@@ -92,7 +91,7 @@ error_t initialize_page_map(memory_map_t *map, void *base, size_t memory_size, u
         physaddr_t region_end = map->array[i].location + map->array[i].size;
         while(location + page_size <= region_end && (pages_mapped < pages_needed))
         {
-            void *page = (void*)page_map.bitmap + pages_mapped * page_size;
+            void *page = (void*)page_alloc.block_map + pages_mapped * page_size;
             for(int level = 0; level < page_table_levels; level++)
             {
                 if(!(get_pte_type(page, level) & PAGE_PRESENT))
@@ -117,13 +116,30 @@ error_t initialize_page_map(memory_map_t *map, void *base, size_t memory_size, u
             continue;
         }
     }
+
+    printf("Initializing page allocator...\n");
  
-    if(initialize_heap(&page_map, map, NULL))
+    if(buddy_alloc_init(&page_alloc, map))
     {
         return ENOMEM;
     }
     else
     {
+        printf("page_alloc = {\n\t" \ 
+            "avail = %08x\n\t" \
+            "block_map = %08x\n\t" \
+            "block_map_size = %08x\n\t" \
+            "max_kval = %i\n\t" \
+            "block_size = %i\n\t" \
+            "offset = %08x\n\t" \
+            "free_block_count = %08x\n}",
+            page_alloc.avail, 
+            page_alloc.block_map, 
+            page_alloc.block_map_size, 
+            page_alloc.max_kval, 
+            page_alloc.block_size, 
+            page_alloc.offset, 
+            page_alloc.free_block_count);
         return ENONE;
     }
 }