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/**
* @file virtalloc.h
*
* @author Freya Murphy <freya@freyacat.org>
*
* Virtural address allocator functions
*/
#ifndef VIRTALLOC_H_
#define VIRTALLOC_H_
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#define BOOTSTRAP_VIRT_ALLOC_NODES 256
struct virt_addr_node {
/// first virtural address
uintptr_t start;
/// last virtural address
uintptr_t end;
/// next node in linked list
struct virt_addr_node *next;
/// prev node in linked list
struct virt_addr_node *prev;
/// if this node is storing any allocated data
uint8_t is_alloc;
/// if this node is in use by virtalloc
uint8_t is_used;
};
struct virt_ctx {
/// bootstrap nodes for the context (not in heap)
struct virt_addr_node bootstrap_nodes[BOOTSTRAP_VIRT_ALLOC_NODES];
/// heap allocated nodes
struct virt_addr_node *alloc_nodes;
/// start node
struct virt_addr_node *start_node;
/// index of first free node
size_t free_node_start;
/// number of heap allocated nodes
size_t alloc_node_count;
/// number of used nodes
size_t used_node_count;
/// if we are currently allocating (recursion check)
bool is_allocating;
};
/**
* Initalizes the virtual address allocator
*/
void virtaddr_init(struct virt_ctx *ctx);
/**
* Clone the virtual address allocator
*/
int virtaddr_clone(struct virt_ctx *old, struct virt_ctx *new);
/**
* Allocate a virtual address of length x pages
* @param pages - x pages
* @returns virt addr
*/
void *virtaddr_alloc(struct virt_ctx *ctx, int pages);
/**
* Take (yoink) a predefined virtual address of length x pages
* @param virt - the start of the vitural address to take
* @param pages - x pages
* @returns 0 on success, 1 on err
*/
int virtaddr_take(struct virt_ctx *ctx, const void *virt, int pages);
/**
* Free the virtual address from virtaddr_alloc
* @param virtaddr - the addr to free
* @returns number of pages used for virtaddr
*/
long virtaddr_free(struct virt_ctx *ctx, const void *virtaddr);
/**
* Cleans up heap allocations and frees the virtalloc context
*/
void virtaddr_cleanup(struct virt_ctx *ctx);
#endif /* virtalloc.h */
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