void __kunmap_atomic(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int idx, type;
if (kvaddr >= (void *)FIXADDR_START) {
type = kmap_atomic_idx();
idx = type + KM_TYPE_NR * smp_processor_id();
if (cache_is_vivt())
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
set_pte_ext(TOP_PTE(vaddr), __pte(0), 0);
local_flush_tlb_kernel_page(vaddr);
#else
(void) idx; /* to kill a warning */
#endif
kmap_atomic_idx_pop();
} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
/* this address was obtained through kmap_high_get() */
kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
}
pagefault_enable();
}
struct page *kmap_to_page(void *ptr)
{
struct page *page;
if ((unsigned long)ptr < PKMAP_ADDR(0))
return virt_to_page(ptr);
page = pte_page(pkmap_page_table[PKMAP_NR((unsigned long)ptr)]);
return page;
}
void kunmap_virt(void *ptr)
{
struct page *page;
if ((unsigned long)ptr < PKMAP_ADDR(0))
return;
page = pte_page(pkmap_page_table[PKMAP_NR((unsigned long)ptr)]);
kunmap(page);
}
void fastcall *kmap_high(struct page *page)
{
unsigned long vaddr;
/*
* For highmem pages, we can't trust "virtual" until
* after we have the lock.
*
* We cannot call this from interrupts, as it may block
*/
spin_lock(&kmap_lock);
vaddr = (unsigned long)page_address(page);
if (!vaddr)
vaddr = map_new_virtual(page);
pkmap_count[PKMAP_NR(vaddr)]++;
if (pkmap_count[PKMAP_NR(vaddr)] < 2)
BUG();
spin_unlock(&kmap_lock);
return (void*) vaddr;
}
struct page *kmap_atomic_to_page(const void *ptr)
{
unsigned long vaddr = (unsigned long)ptr;
pte_t *pte;
if (vaddr < FIXADDR_START) {
if (vaddr >= PKMAP_ADDR(0) &&
vaddr < PKMAP_ADDR(LAST_PKMAP))
return pte_page(pkmap_page_table[PKMAP_NR(vaddr)]);
else
return virt_to_page(ptr);
}
pte = TOP_PTE(vaddr);
return pte_page(*pte);
}
void fastcall kunmap_high(struct page *page)
{
unsigned long vaddr;
unsigned long nr;
int need_wakeup;
spin_lock(&kmap_lock);
vaddr = (unsigned long)page_address(page);
if (!vaddr)
BUG();
nr = PKMAP_NR(vaddr);
/*
* A count must never go down to zero
* without a TLB flush!
*/
need_wakeup = 0;
switch (--pkmap_count[nr]) {
case 0:
BUG();
case 1:
/*
* Avoid an unnecessary wake_up() function call.
* The common case is pkmap_count[] == 1, but
* no waiters.
* The tasks queued in the wait-queue are guarded
* by both the lock in the wait-queue-head and by
* the kmap_lock. As the kmap_lock is held here,
* no need for the wait-queue-head's lock. Simply
* test if the queue is empty.
*/
need_wakeup = waitqueue_active(&pkmap_map_wait);
}
spin_unlock(&kmap_lock);
/* do wake-up, if needed, race-free outside of the spin lock */
if (need_wakeup)
wake_up(&pkmap_map_wait);
}
