# HG changeset patch
# User John Tsiombikas <nuclear@mutantstargoat.com>
# Date 1318209361 -10800
# Node ID 0a205396e1a0057769dba7515b610f163e7853bd
# Parent  ebca81749ef5237ab7e891bdb4aa737d792aa5cc
- added a generic red-black tree data structure
- added a VM map as an red-black tree of vm_pages in the process structure
- constructed the vm map of the memory passed by the kernel initially to the first process.

diff -r ebca81749ef5 -r 0a205396e1a0 src/proc.c
--- a/src/proc.c	Sun Oct 09 20:38:35 2011 +0300
+++ b/src/proc.c	Mon Oct 10 04:16:01 2011 +0300
@@ -131,6 +131,9 @@
 	/* make it current */
 	set_current_pid(p->id);
 
+	/* build the current vm map */
+	cons_vmmap(&p->vmmap);
+
 	/* execute a fake return from interrupt with the fake stack frame */
 	intr_ret(ifrm);
 }
diff -r ebca81749ef5 -r 0a205396e1a0 src/proc.h
--- a/src/proc.h	Sun Oct 09 20:38:35 2011 +0300
+++ b/src/proc.h	Mon Oct 10 04:16:01 2011 +0300
@@ -3,6 +3,7 @@
 
 #include <inttypes.h>
 #include "asmops.h"
+#include "rbtree.h"
 
 #define MAX_PROC	128
 
@@ -31,6 +32,9 @@
 
 	int ticks_left;
 
+	/* process vm map */
+	struct rbtree vmmap;
+
 	/* extends of the process heap, increased by sbrk */
 
 	/* first page of the user stack, extends up to KMEM_START */
diff -r ebca81749ef5 -r 0a205396e1a0 src/rbtree.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/rbtree.c	Mon Oct 10 04:16:01 2011 +0300
@@ -0,0 +1,457 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "rbtree.h"
+
+#define INT2PTR(x)	((void*)(x))
+#define PTR2INT(x)	((int)(x))
+
+static int cmpaddr(void *ap, void *bp);
+static int cmpint(void *ap, void *bp);
+
+static int count_nodes(struct rbnode *node);
+static void del_tree(struct rbnode *node, void (*delfunc)(struct rbnode*, void*), void *cls);
+static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data);
+static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key);
+/*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key);*/
+static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls);
+
+struct rbtree *rb_create(rb_cmp_func_t cmp_func)
+{
+	struct rbtree *rb;
+
+	if(!(rb = malloc(sizeof *rb))) {
+		return 0;
+	}
+	if(rb_init(rb, cmp_func) == -1) {
+		free(rb);
+		return 0;
+	}
+	return rb;
+}
+
+void rb_free(struct rbtree *rb)
+{
+	rb_destroy(rb);
+	free(rb);
+}
+
+
+int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func)
+{
+	memset(rb, 0, sizeof *rb);
+
+	if(cmp_func == RB_KEY_INT) {
+		rb->cmp = cmpint;
+	} else if(cmp_func == RB_KEY_STRING) {
+		rb->cmp = (rb_cmp_func_t)strcmp;
+	} else {
+		rb->cmp = cmpaddr;
+	}
+
+	rb->alloc = malloc;
+	rb->free = free;
+	return 0;
+}
+
+void rb_destroy(struct rbtree *rb)
+{
+	del_tree(rb->root, rb->del, rb->del_cls);
+}
+
+void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free)
+{
+	rb->alloc = alloc;
+	rb->free = free;
+}
+
+
+void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func)
+{
+	rb->cmp = func;
+}
+
+void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls)
+{
+	rb->del = func;
+	rb->del_cls = cls;
+}
+
+int rb_size(struct rbtree *rb)
+{
+	return count_nodes(rb->root);
+}
+
+int rb_insert(struct rbtree *rb, void *key, void *data)
+{
+	rb->root = insert(rb, rb->root, key, data);
+	rb->root->red = 0;
+	return 0;
+}
+
+int rb_inserti(struct rbtree *rb, int key, void *data)
+{
+	rb->root = insert(rb, rb->root, INT2PTR(key), data);
+	rb->root->red = 0;
+	return 0;
+}
+
+
+int rb_delete(struct rbtree *rb, void *key)
+{
+	rb->root = delete(rb, rb->root, key);
+	rb->root->red = 0;
+	return 0;
+}
+
+int rb_deletei(struct rbtree *rb, int key)
+{
+	rb->root = delete(rb, rb->root, INT2PTR(key));
+	rb->root->red = 0;
+	return 0;
+}
+
+
+void *rb_find(struct rbtree *rb, void *key)
+{
+	struct rbnode *node = rb->root;
+
+	while(node) {
+		int cmp = rb->cmp(key, node->key);
+		if(cmp == 0) {
+			return node;
+		}
+		node = cmp < 0 ? node->left : node->right;
+	}
+	return 0;
+}
+
+void *rb_findi(struct rbtree *rb, int key)
+{
+	return rb_find(rb, INT2PTR(key));
+}
+
+
+void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls)
+{
+	traverse(rb->root, func, cls);
+}
+
+
+struct rbnode *rb_root(struct rbtree *rb)
+{
+	return rb->root;
+}
+
+void rb_begin(struct rbtree *rb)
+{
+	rb->rstack = 0;
+	rb->iter = rb->root;
+}
+
+#define push(sp, x)		((x)->next = (sp), (sp) = (x))
+#define pop(sp)			((sp) = (sp)->next)
+#define top(sp)			(sp)
+
+struct rbnode *rb_next(struct rbtree *rb)
+{
+	struct rbnode *res = 0;
+
+	while(rb->rstack || rb->iter) {
+		if(rb->iter) {
+			push(rb->rstack, rb->iter);
+			rb->iter = rb->iter->left;
+		} else {
+			rb->iter = top(rb->rstack);
+			pop(rb->rstack);
+			res = rb->iter;
+			rb->iter = rb->iter->right;
+			break;
+		}
+	}
+	return res;
+}
+
+void *rb_node_key(struct rbnode *node)
+{
+	return node ? node->key : 0;
+}
+
+int rb_node_keyi(struct rbnode *node)
+{
+	return node ? PTR2INT(node->key) : 0;
+}
+
+void *rb_node_data(struct rbnode *node)
+{
+	return node ? node->data : 0;
+}
+
+static int cmpaddr(void *ap, void *bp)
+{
+	return ap < bp ? -1 : (ap > bp ? 1 : 0);
+}
+
+static int cmpint(void *ap, void *bp)
+{
+	return PTR2INT(ap) - PTR2INT(bp);
+}
+
+
+/* ---- left-leaning 2-3 red-black implementation ---- */
+
+/* helper prototypes */
+static int is_red(struct rbnode *tree);
+static void color_flip(struct rbnode *tree);
+static struct rbnode *rot_left(struct rbnode *a);
+static struct rbnode *rot_right(struct rbnode *a);
+static struct rbnode *find_min(struct rbnode *tree);
+static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree);
+/*static struct rbnode *move_red_right(struct rbnode *tree);*/
+static struct rbnode *move_red_left(struct rbnode *tree);
+static struct rbnode *fix_up(struct rbnode *tree);
+
+static int count_nodes(struct rbnode *node)
+{
+	if(!node)
+		return 0;
+
+	return 1 + count_nodes(node->left) + count_nodes(node->right);
+}
+
+static void del_tree(struct rbnode *node, rb_del_func_t delfunc, void *cls)
+{
+	if(!node)
+		return;
+
+	del_tree(node->left, delfunc, cls);
+	del_tree(node->right, delfunc, cls);
+
+	delfunc(node, cls);
+	free(node);
+}
+
+static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data)
+{
+	int cmp;
+
+	if(!tree) {
+		struct rbnode *node = rb->alloc(sizeof *node);
+		node->red = 1;
+		node->key = key;
+		node->data = data;
+		node->left = node->right = 0;
+		return node;
+	}
+
+	cmp = rb->cmp(key, tree->key);
+
+	if(cmp < 0) {
+		tree->left = insert(rb, tree->left, key, data);
+	} else if(cmp > 0) {
+		tree->right = insert(rb, tree->right, key, data);
+	} else {
+		tree->data = data;
+	}
+
+	/* fix right-leaning reds */
+	if(is_red(tree->right)) {
+		tree = rot_left(tree);
+	}
+	/* fix two reds in a row */
+	if(is_red(tree->left) && is_red(tree->left->left)) {
+		tree = rot_right(tree);
+	}
+
+	/* if 4-node, split it by color inversion */
+	if(is_red(tree->left) && is_red(tree->right)) {
+		color_flip(tree);
+	}
+
+	return tree;
+}
+
+static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key)
+{
+	int cmp;
+
+	if(!tree) {
+		return 0;
+	}
+
+	cmp = rb->cmp(key, tree->key);
+
+	if(cmp < 0) {
+		if(!is_red(tree->left) && !is_red(tree->left->left)) {
+			tree = move_red_left(tree);
+		}
+		tree->left = delete(rb, tree->left, key);
+	} else {
+		/* need reds on the right */
+		if(is_red(tree->left)) {
+			tree = rot_right(tree);
+		}
+
+		/* found it at the bottom (XXX what certifies left is null?) */
+		if(cmp == 0 && !tree->right) {
+			if(rb->del) {
+				rb->del(tree, rb->del_cls);
+			}
+			rb->free(tree);
+			return 0;
+		}
+
+		if(!is_red(tree->right) && !is_red(tree->right->left)) {
+			tree = move_red_left(tree);
+		}
+
+		if(key == tree->key) {
+			struct rbnode *rmin = find_min(tree->right);
+			tree->key = rmin->key;
+			tree->data = rmin->data;
+			tree->right = del_min(rb, tree->right);
+		} else {
+			tree->right = delete(rb, tree->right, key);
+		}
+	}
+
+	return fix_up(tree);
+}
+
+/*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key)
+{
+	int cmp;
+
+	if(!node)
+		return 0;
+
+	if((cmp = rb->cmp(key, node->key)) == 0) {
+		return node;
+	}
+	return find(rb, cmp < 0 ? node->left : node->right, key);
+}*/
+
+static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls)
+{
+	if(!node)
+		return;
+
+	traverse(node->left, func, cls);
+	func(node, cls);
+	traverse(node->right, func, cls);
+}
+
+/* helpers */
+
+static int is_red(struct rbnode *tree)
+{
+	return tree && tree->red;
+}
+
+static void color_flip(struct rbnode *tree)
+{
+	tree->red = !tree->red;
+	tree->left->red = !tree->left->red;
+	tree->right->red = !tree->right->red;
+}
+
+static struct rbnode *rot_left(struct rbnode *a)
+{
+	struct rbnode *b = a->right;
+	a->right = b->left;
+	b->left = a;
+	b->red = a->red;
+	a->red = 1;
+	return b;
+}
+
+static struct rbnode *rot_right(struct rbnode *a)
+{
+	struct rbnode *b = a->left;
+	a->left = b->right;
+	b->right = a;
+	b->red = a->red;
+	a->red = 1;
+	return b;
+}
+
+static struct rbnode *find_min(struct rbnode *tree)
+{
+	struct rbnode *node;
+
+	if(!tree)
+		return 0;
+
+	while(node->left) {
+		node = node->left;
+	}
+	return node;
+}
+
+static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree)
+{
+	if(!tree->left) {
+		if(rb->del) {
+			rb->del(tree->left, rb->del_cls);
+		}
+		rb->free(tree->left);
+		return 0;
+	}
+
+	/* make sure we've got red (3/4-nodes) at the left side so we can delete at the bottom */
+	if(!is_red(tree->left) && !is_red(tree->left->left)) {
+		tree = move_red_left(tree);
+	}
+	tree->left = del_min(rb, tree->left);
+
+	/* fix right-reds, red-reds, and split 4-nodes on the way up */
+	return fix_up(tree);
+}
+
+#if 0
+/* push a red link on this node to the right */
+static struct rbnode *move_red_right(struct rbnode *tree)
+{
+	/* flipping it makes both children go red, so we have a red to the right */
+	color_flip(tree);
+
+	/* if after the flip we've got a red-red situation to the left, fix it */
+	if(is_red(tree->left->left)) {
+		tree = rot_right(tree);
+		color_flip(tree);
+	}
+	return tree;
+}
+#endif
+
+/* push a red link on this node to the left */
+static struct rbnode *move_red_left(struct rbnode *tree)
+{
+	/* flipping it makes both children go red, so we have a red to the left */
+	color_flip(tree);
+
+	/* if after the flip we've got a red-red on the right-left, fix it */
+	if(is_red(tree->right->left)) {
+		tree->right = rot_right(tree->right);
+		tree = rot_left(tree);
+		color_flip(tree);
+	}
+	return tree;
+}
+
+static struct rbnode *fix_up(struct rbnode *tree)
+{
+	/* fix right-leaning */
+	if(is_red(tree->right)) {
+		tree = rot_left(tree);
+	}
+	/* change invalid red-red pairs into a proper 4-node */
+	if(is_red(tree->left) && is_red(tree->left->left)) {
+		tree = rot_right(tree);
+	}
+	/* split 4-nodes */
+	if(is_red(tree->left) && is_red(tree->right)) {
+		color_flip(tree);
+	}
+	return tree;
+}
diff -r ebca81749ef5 -r 0a205396e1a0 src/rbtree.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/rbtree.h	Mon Oct 10 04:16:01 2011 +0300
@@ -0,0 +1,82 @@
+#ifndef RBTREE_H_
+#define RBTREE_H_
+
+struct rbtree;
+struct rbnode;
+
+
+typedef void *(*rb_alloc_func_t)(size_t);
+typedef void (*rb_free_func_t)(void*);
+
+typedef int (*rb_cmp_func_t)(void*, void*);
+typedef void (*rb_del_func_t)(struct rbnode*, void*);
+
+
+struct rbtree {
+	struct rbnode *root;
+
+	rb_alloc_func_t alloc;
+	rb_free_func_t free;
+
+	rb_cmp_func_t cmp;
+	rb_del_func_t del;
+	void *del_cls;
+
+	struct rbnode *rstack, *iter;
+};
+
+
+struct rbnode {
+	void *key, *data;
+	int red;
+	struct rbnode *left, *right;
+	struct rbnode *next;	/* for iterator stack */
+};
+
+#define RB_KEY_ADDR		(rb_cmp_func_t)(0)
+#define RB_KEY_INT		(rb_cmp_func_t)(1)
+#define RB_KEY_STRING	(rb_cmp_func_t)(3)
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct rbtree *rb_create(rb_cmp_func_t cmp_func);
+void rb_free(struct rbtree *rb);
+
+int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func);
+void rb_destroy(struct rbtree *rb);
+
+void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free);
+void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func);
+void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls);
+
+int rb_size(struct rbtree *rb);
+
+int rb_insert(struct rbtree *rb, void *key, void *data);
+int rb_inserti(struct rbtree *rb, int key, void *data);
+
+int rb_delete(struct rbtree *rb, void *key);
+int rb_deletei(struct rbtree *rb, int key);
+
+void *rb_find(struct rbtree *rb, void *key);
+void *rb_findi(struct rbtree *rb, int key);
+
+void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls);
+
+struct rbnode *rb_root(struct rbtree *rb);
+
+void rb_begin(struct rbtree *rb);
+struct rbnode *rb_next(struct rbtree *rb);
+
+void *rb_node_key(struct rbnode *node);
+int rb_node_keyi(struct rbnode *node);
+void *rb_node_data(struct rbnode *node);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif	/* RBTREE_H_ */
diff -r ebca81749ef5 -r 0a205396e1a0 src/vm.c
--- a/src/vm.c	Sun Oct 09 20:38:35 2011 +0300
+++ b/src/vm.c	Mon Oct 10 04:16:01 2011 +0300
@@ -17,7 +17,6 @@
 
 #define ATTR_PGDIR_MASK	0x3f
 #define ATTR_PGTBL_MASK	0x1ff
-#define ADDR_PGENT_MASK	0xfffff000
 
 #define PAGEFAULT		14
 
@@ -68,7 +67,7 @@
 	map_mem_range(IDMAP_START, idmap_end - IDMAP_START, IDMAP_START, 0);
 
 	/* make the last page directory entry point to the page directory */
-	pgdir[1023] = ((uint32_t)pgdir & ADDR_PGENT_MASK) | PG_PRESENT;
+	pgdir[1023] = ((uint32_t)pgdir & PGENT_ADDR_MASK) | PG_PRESENT;
 	pgdir = (uint32_t*)PGDIR_ADDR;
 
 	/* set the page fault handler */
@@ -149,7 +148,7 @@
 		if(pgon) {
 			pgtbl = PGTBL(diridx);
 		} else {
-			pgtbl = (uint32_t*)(pgdir[diridx] & ADDR_PGENT_MASK);
+			pgtbl = (uint32_t*)(pgdir[diridx] & PGENT_ADDR_MASK);
 		}
 	}
 
@@ -614,7 +613,8 @@
 				 * page table and unset the writable bits.
 				 */
 				for(j=0; j<1024; j++) {
-					PGTBL(i)[j] &= ~(uint32_t)PG_WRITABLE;
+					clear_page_bit(i * 1024 + j, PG_WRITABLE, PAGE_ONLY);
+					/*PGTBL(i)[j] &= ~(uint32_t)PG_WRITABLE;*/
 				}
 			}
 
@@ -699,6 +699,40 @@
 }
 
 
+#define USER_PGDIR_ENTRIES	PAGE_TO_PGTBL(KMEM_START_PAGE)
+int cons_vmmap(struct rbtree *vmmap)
+{
+	int i, j;
+
+	rb_init(vmmap, RB_KEY_INT);
+
+	for(i=0; i<USER_PGDIR_ENTRIES; i++) {
+		if(pgdir[i] & PG_PRESENT) {
+			/* page table is present, iterate through its 1024 pages */
+			uint32_t *pgtbl = PGTBL(i);
+
+			for(j=0; j<1024; j++) {
+				if(pgtbl[j] & PG_PRESENT) {
+					struct vm_page *vmp;
+
+					if(!(vmp = malloc(sizeof *vmp))) {
+						panic("cons_vmap failed to allocate memory");
+					}
+					vmp->vpage = i * 1024 + j;
+					vmp->ppage = ADDR_TO_PAGE(pgtbl[j] & PGENT_ADDR_MASK);
+					vmp->flags = pgtbl[j] & ATTR_PGTBL_MASK;
+					vmp->nref = 1;	/* when first created assume no sharing */
+
+					rb_inserti(vmmap, vmp->ppage, vmp);
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+
 void dbg_print_vm(int area)
 {
 	struct page_range *node;
diff -r ebca81749ef5 -r 0a205396e1a0 src/vm.h
--- a/src/vm.h	Sun Oct 09 20:38:35 2011 +0300
+++ b/src/vm.h	Mon Oct 10 04:16:01 2011 +0300
@@ -3,8 +3,10 @@
 
 #include <stdlib.h>
 #include "mboot.h"
+#include "rbtree.h"
 
 #define KMEM_START		0xc0000000
+#define KMEM_START_PAGE	ADDR_TO_PAGE(KMEM_START)
 
 /* page mapping flags */
 #define PG_PRESENT			(1 << 0)
@@ -44,6 +46,13 @@
 #define PAGE_ONLY		0
 #define WHOLE_PATH		1
 
+struct vm_page {
+	int vpage, ppage;
+	unsigned int flags;
+
+	int nref;
+};
+
 void init_vm(void);
 
 int map_page(int vpage, int ppage, unsigned int attr);
@@ -70,6 +79,9 @@
 void set_page_bit(int pgnum, uint32_t bit, int wholepath);
 void clear_page_bit(int pgnum, uint32_t bit, int wholepath);
 
+/* construct the vm map for the current user mappings */
+int cons_vmmap(struct rbtree *vmmap);
+
 void dbg_print_vm(int area);
 
 /* defined in vm-asm.S */