1 files changed, 54 insertions, 27 deletions

diff --git a/src/memory/virtalloc.c b/src/memory/virtalloc.c
index 781fc9b..2ab9fc2 100644
--- a/src/memory/virtalloc.c
+++ b/src/memory/virtalloc.c
@@ -1,6 +1,9 @@
+#include "lib.h"
+#include "panic.h"
 #include <stdint.h>
 #include <stddef.h>
 #include <memory.h>
+#include <string.h>
 
 #define MEMORY_INTERNAL
 #include <memory/virtalloc.h>
@@ -10,34 +13,60 @@ struct addr_node {
 	uintptr_t end;
 	struct addr_node *next;
 	struct addr_node *prev;
-	uint8_t is_alloc;
-	uint8_t is_bss;
+	uint8_t is_alloc;        // if node is storing allocated data
+	uint8_t is_used;         // if node is in use by virtalloc
 };
 
-#define BOOTSTRAP_BSS_NODES 16
-static uint8_t bss_nodes = 0;
-static struct addr_node nodes[BOOTSTRAP_BSS_NODES];
+#define BSS_NODES 64
+static struct addr_node bootstrap_nodes[BSS_NODES];
+static struct addr_node *alloc_nodes = NULL;
+static size_t free_node_start = 0;
+static size_t alloc_node_count = 0;
+static size_t used_node_count = 0;
+static bool is_allocating = false;
 
-static struct addr_node *start_node;
+static struct addr_node *start_node = NULL;
 
-static struct addr_node *alloc_node(void) {
-	struct addr_node *node = NULL;
-	if (bss_nodes >= BOOTSTRAP_BSS_NODES) {
-		node = kalloc(sizeof(struct addr_node));
-		if (node == NULL)
-			return NULL;
-		node->is_bss = false;
+static struct addr_node *get_node_idx(int idx) {
+	if (idx < BSS_NODES) {
+		return &bootstrap_nodes[idx];
 	} else {
-		node = &nodes[bss_nodes];
-		bss_nodes += 1;
-		node->is_bss = true;
+		return &alloc_nodes[idx - BSS_NODES];
 	}
-	return node;
+}
+
+static struct addr_node *get_node(void) {
+	size_t count = BSS_NODES + alloc_node_count;
+
+	if (!is_allocating && used_node_count + 16 >= count) {
+		is_allocating = true;
+		int new_alloc = alloc_node_count * 2;
+		if (new_alloc < 8)
+			new_alloc = 8;
+		int allocated = new_alloc - alloc_node_count;
+		int old = new_alloc - allocated;
+		alloc_nodes = krealloc(alloc_nodes, sizeof(struct addr_node) * new_alloc);
+		memset(alloc_nodes + old, 0, sizeof(struct addr_node) + allocated);;
+		alloc_node_count = new_alloc;
+		is_allocating = false;
+		count = BSS_NODES + alloc_node_count;
+	}
+
+	size_t idx = free_node_start;
+	for (; idx < count; idx++) {
+		struct addr_node *node = get_node_idx(idx);
+		if (!node->is_used) {
+			used_node_count++;
+			return node;
+		}
+	}
+
+	panic("could not get virtaddr node");
 }
 
 static void free_node(struct addr_node *node) {
-	if (!node->is_bss)
-		kfree(node);
+	node->is_used = false;
+	used_node_count--;
 }
 
 void virtaddr_init(void) {
@@ -47,11 +76,11 @@ void virtaddr_init(void) {
 		.next = NULL,
 		.prev = NULL,
 		.is_alloc = false,
-		.is_bss = true,
+		.is_used = true,
 	};
-	nodes[0] = init;
-	start_node = &nodes[0];
-	bss_nodes++;
+	memset(bootstrap_nodes, 0, sizeof(bootstrap_nodes));
+	bootstrap_nodes[0] = init;
+	start_node = &bootstrap_nodes[0];
 }
 
 void *virtaddr_alloc(int n_pages) {
@@ -69,10 +98,7 @@ void *virtaddr_alloc(int n_pages) {
 
 		long length = node->end - node->start;
 		if (length >= n_length) {
-			struct addr_node *new = alloc_node();
-			if (node == NULL) {
-				return NULL;
-			}
+			struct addr_node *new = get_node();
 			if (node->prev != NULL) {
 				node->prev->next = new;
 			}
@@ -82,6 +108,7 @@ void *virtaddr_alloc(int n_pages) {
 			new->end = new->start + n_length;
 			node->start = new->end;
 			new->is_alloc = true;
+			new->is_used = true;
 			new->next = node;
 			return (void *) new->start;
 		}