added more generic kalloc1k() and kfree1k() to replace allocate_page_…

…table().

include/kalloc.h

@@ -19,5 +19,7 @@ struct PageList {
 void kalloc_init(uint32_t start, uint32_t end);
 void *kalloc();
 void kfree(void *page);
+void *kalloc1k();
+void kfree1k(void *page);
 
 #endif

kernel/kalloc.c

@@ -10,7 +10,8 @@ static struct PageList *page_list_prepend(struct PageList *page_list,
  * list nodes are stored in the beginning of the actual page, because
  * the page is free and we can use it for our purposes.
  */
-static struct PageList *free_list = NULL;
+static struct PageList *free_list_4k = NULL;
+static struct PageList *free_list_1k = NULL;
 
 /* kalloc_init adds the given address range to the free list. */
 void kalloc_init(uint32_t start, uint32_t end)
@@ -23,7 +24,7 @@ void kalloc_init(uint32_t start, uint32_t end)
 	for (current_page = start_address; current_page != end_address;
 	     current_page += PAGE_SIZE)
 	{
-		free_list = page_list_prepend(free_list, current_page);
+		free_list_4k = page_list_prepend(free_list_4k, current_page);
 	}
 }
 
@@ -32,9 +33,9 @@ void *kalloc()
 {
 	void *result = NULL;
 
-	if (free_list != NULL) {
-		result = free_list;
-		free_list = free_list->next;
+	if (free_list_4k != NULL) {
+		result = free_list_4k;
+		free_list_4k = free_list_4k->next;
 	}
 
 	return result;
@@ -43,7 +44,34 @@ void *kalloc()
 /* kfree adds the given page to the free list. */
 void kfree(void *page)
 {
-	free_list = page_list_prepend(free_list, page);
+	free_list_4k = page_list_prepend(free_list_4k, page);
+}
+
+void *kalloc1k()
+{
+	void *result = NULL;
+
+	if (free_list_1k == NULL) {
+		char *page = kalloc();
+		if (page != NULL) {
+			kfree1k(page);
+			kfree1k(page + 1024);
+			kfree1k(page + 2048);
+			kfree1k(page + 3072);
+		}
+	}
+
+	if (free_list_1k != NULL) {
+		result = free_list_1k;
+		free_list_1k = free_list_1k->next;
+	}
+
+	return result;
+}
+
+void kfree1k(void *page)
+{
+	free_list_1k = page_list_prepend(free_list_1k, page);
 }
 
 /*

kernel/memory.c

@@ -7,7 +7,6 @@
 /* forward declarations for local functions */
 static void map_page(struct SectionTableEntry *vm, uint32_t physical,
 		     uint32_t virtual, int access_permissions);
-static struct PageTableEntry *allocate_page_table();
 
 /* kernel virtual to physical memory mappings */
 static struct MemoryMapping kernel_mappings[] = {
@@ -22,9 +21,6 @@ static struct MemoryMapping kernel_mappings[] = {
 
 const int kernel_mapping_count = 6;
 
-static char *page_table_allocated_page = NULL;
-static int page_table_page_offset = 0;
-
 /*
  * memory_init sets up a two level page table. This function only sets
  * up the kernel part of the address space. The user part of the address
@@ -34,9 +30,6 @@ void memory_init(void)
 {
 	struct SectionTableEntry *kernel_vm = NULL;
 
-	page_table_allocated_page = NULL;
-	page_table_page_offset = 0;
-
 	kernel_vm = (void *) ROUND_UP(KERNEL_SECTION_TABLE,
 				      SECTION_TABLE_ALIGNMENT);
 	setup_kernel_vm(kernel_vm);
@@ -100,7 +93,7 @@ static void map_page(struct SectionTableEntry *vm, uint32_t physical,
 
 	/* if this section is not mapped before, map it to a new page table */
 	if (vm[section_index].base_address == 0) {
-		page_table = allocate_page_table();
+		page_table = kalloc1k();
 		memset(page_table, 0, PAGE_TABLE_SIZE);
 
 		vm[section_index].base_address = PAGE_TABLE_TO_BASE(V2P(page_table));
@@ -120,29 +113,6 @@ static void map_page(struct SectionTableEntry *vm, uint32_t physical,
 	page_table[page_index].base_address = PAGE_TO_BASE(physical);
 }
 
-/*
- * allocate_page_table. this function assumes page size is an integer multiple
- * of page table size.
- */
-static struct PageTableEntry *allocate_page_table()
-{
-	void *result = NULL;
-
-	/*
-	 * If this is the first call or the previous page is full, allocate
-	 * a new page.
-	 */
-	if (page_table_allocated_page == NULL || page_table_page_offset == PAGE_SIZE) {
-		page_table_allocated_page = kalloc();
-		page_table_page_offset = 0;
-	}
-
-	result = page_table_allocated_page + page_table_page_offset;
-	page_table_page_offset += PAGE_TABLE_SIZE;
-
-	return result;
-}
-
 /*
  * resolve_physical_address simulates the virtual memory hardware and maps the
  * given virtual address to physical address. This function can be used for