kolibrios/drivers/ddk/linux/kmap.c

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#include <ddk.h>
#include <linux/mm.h>
#include <syscall.h>
#define KMAP_MAX 256
static struct mutex kmap_mutex;
static struct page* kmap_table[KMAP_MAX];
static int kmap_av;
static int kmap_first;
static void* kmap_base;
int kmap_init()
{
kmap_base = AllocKernelSpace(KMAP_MAX*4096);
if(kmap_base == NULL)
return -1;
kmap_av = KMAP_MAX;
MutexInit(&kmap_mutex);
return 0;
};
void *kmap(struct page *page)
{
void *vaddr = NULL;
int i;
do
{
MutexLock(&kmap_mutex);
if(kmap_av != 0)
{
for(i = kmap_first; i < KMAP_MAX; i++)
{
if(kmap_table[i] == NULL)
{
kmap_av--;
kmap_first = i;
kmap_table[i] = page;
vaddr = kmap_base + (i<<12);
MapPage(vaddr,(addr_t)page,3);
break;
};
};
};
MutexUnlock(&kmap_mutex);
}while(vaddr == NULL);
return vaddr;
};
void *kmap_atomic(struct page *page) __attribute__ ((alias ("kmap")));
void kunmap(struct page *page)
{
void *vaddr;
int i;
MutexLock(&kmap_mutex);
for(i = 0; i < KMAP_MAX; i++)
{
if(kmap_table[i] == page)
{
kmap_av++;
if(i < kmap_first)
kmap_first = i;
kmap_table[i] = NULL;
vaddr = kmap_base + (i<<12);
MapPage(vaddr,0,0);
break;
};
};
MutexUnlock(&kmap_mutex);
};
void kunmap_atomic(void *vaddr)
{
int i;
MapPage(vaddr,0,0);
i = (vaddr - kmap_base) >> 12;
MutexLock(&kmap_mutex);
kmap_av++;
if(i < kmap_first)
kmap_first = i;
kmap_table[i] = NULL;
MutexUnlock(&kmap_mutex);
}