matos/core/allocArea.c

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C
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2021-02-10 23:22:57 +01:00
#include "allocArea.h"
#include "alloc.h"
#include "assert.h"
#include "kernel.h"
#include "list.h"
#include "mem.h"
#include "stdarg.h"
struct memArea {
vaddr_t startAddr;
uint nbPages;
struct memArea *next;
struct memArea *prev;
};
static struct memArea *freeArea;
static struct memArea *usedArea;
void areaInit(void)
{
list_init(freeArea);
list_init(usedArea);
}
struct memArea *areaFindFit(unsigned int nbPages)
{
struct memArea *area;
int count;
list_foreach(freeArea, area, count)
{
if (area->nbPages >= nbPages)
return area;
}
return NULL;
}
static void insertSorted(struct memArea *list, struct memArea *item)
{
struct memArea *prev, *cur;
int count;
prev = NULL;
list_foreach(list, cur, count)
{
if (cur->startAddr > item->startAddr)
break;
prev = cur;
}
if (prev)
list_insert_after(list, prev, item);
else
list_add_tail(list, item);
}
vaddr_t areaAlloc(unsigned int nbPages)
{
struct memArea *area, *allocated;
area = areaFindFit(nbPages);
if (!area)
return (vaddr_t)NULL;
if (area->nbPages == nbPages) {
list_delete(freeArea, area);
insertSorted(usedArea, area);
allocated = area;
}
struct memArea *newArea = (struct memArea *)malloc(sizeof(struct memArea));
if (!newArea)
return (vaddr_t)NULL;
// Avoid insertSorted(freeArea, newArea) call by modifying area
newArea->nbPages = nbPages;
newArea->startAddr = area->startAddr;
area->nbPages -= nbPages;
area->startAddr += nbPages * PAGE_SIZE;
insertSorted(usedArea, newArea);
allocated = newArea;
for (uint i = 0; i < nbPages; i++) {
paddr_t page = allocPhyPage(1);
if (page) {
pageMap(area->startAddr + i * PAGE_SIZE, page, PAGING_MEM_WRITE);
} else {
// TODO
assert(1);
}
}
return allocated->startAddr;
}
static int areaMergeFreeArea(struct memArea *prev, struct memArea *next)
{
if (prev->startAddr + prev->nbPages * PAGE_SIZE != next->startAddr) {
return -1;
}
prev->nbPages += next->nbPages;
list_delete(freeArea, next);
free(next);
next = prev;
return 0;
}
static struct memArea *areaFindMemArea(struct memArea *list, vaddr_t addr)
{
struct memArea *area;
int count;
list_foreach(list, area, count)
{
if (area->startAddr <= addr && addr <= area->startAddr + area->nbPages * PAGE_SIZE)
return area;
}
return NULL;
}
int areaFree(vaddr_t addr)
{
struct memArea *area;
area = areaFindMemArea(usedArea, addr);
if (!area) {
pr_info("Cannot find memArea associated to %p\n", addr);
return -1;
}
list_delete(usedArea, area);
insertSorted(freeArea, area);
if (area->prev)
areaMergeFreeArea(area->prev, area);
if (area->next)
areaMergeFreeArea(area, area->next);
return 0;
}