150 lines
3.4 KiB
C
150 lines
3.4 KiB
C
/*
|
|
* arch/arm/mm/highmem.c -- ARM highmem support
|
|
*
|
|
* Author: Nicolas Pitre
|
|
* Created: september 8, 2008
|
|
* Copyright: Marvell Semiconductors Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/interrupt.h>
|
|
#include <asm/fixmap.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/tlbflush.h>
|
|
#include "mm.h"
|
|
|
|
static inline void set_fixmap_pte(int idx, pte_t pte)
|
|
{
|
|
unsigned long vaddr = __fix_to_virt(idx);
|
|
pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
|
|
|
|
set_pte_ext(ptep, pte, 0);
|
|
local_flush_tlb_kernel_page(vaddr);
|
|
}
|
|
|
|
static inline pte_t get_fixmap_pte(unsigned long vaddr)
|
|
{
|
|
pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
|
|
|
|
return *ptep;
|
|
}
|
|
|
|
void *kmap(struct page *page)
|
|
{
|
|
might_sleep();
|
|
if (!PageHighMem(page))
|
|
return page_address(page);
|
|
return kmap_high(page);
|
|
}
|
|
EXPORT_SYMBOL(kmap);
|
|
|
|
void kunmap(struct page *page)
|
|
{
|
|
BUG_ON(in_interrupt());
|
|
if (!PageHighMem(page))
|
|
return;
|
|
kunmap_high(page);
|
|
}
|
|
EXPORT_SYMBOL(kunmap);
|
|
|
|
void *kmap_atomic(struct page *page)
|
|
{
|
|
unsigned int idx;
|
|
unsigned long vaddr;
|
|
void *kmap;
|
|
int type;
|
|
|
|
preempt_disable();
|
|
pagefault_disable();
|
|
if (!PageHighMem(page))
|
|
return page_address(page);
|
|
|
|
#ifdef CONFIG_DEBUG_HIGHMEM
|
|
/*
|
|
* There is no cache coherency issue when non VIVT, so force the
|
|
* dedicated kmap usage for better debugging purposes in that case.
|
|
*/
|
|
if (!cache_is_vivt())
|
|
kmap = NULL;
|
|
else
|
|
#endif
|
|
kmap = kmap_high_get(page);
|
|
if (kmap)
|
|
return kmap;
|
|
|
|
type = kmap_atomic_idx_push();
|
|
|
|
idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
|
|
vaddr = __fix_to_virt(idx);
|
|
#ifdef CONFIG_DEBUG_HIGHMEM
|
|
/*
|
|
* With debugging enabled, kunmap_atomic forces that entry to 0.
|
|
* Make sure it was indeed properly unmapped.
|
|
*/
|
|
BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
|
|
#endif
|
|
/*
|
|
* When debugging is off, kunmap_atomic leaves the previous mapping
|
|
* in place, so the contained TLB flush ensures the TLB is updated
|
|
* with the new mapping.
|
|
*/
|
|
set_fixmap_pte(idx, mk_pte(page, kmap_prot));
|
|
|
|
return (void *)vaddr;
|
|
}
|
|
EXPORT_SYMBOL(kmap_atomic);
|
|
|
|
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 = FIX_KMAP_BEGIN + 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(idx));
|
|
set_fixmap_pte(idx, __pte(0));
|
|
#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();
|
|
preempt_enable();
|
|
}
|
|
EXPORT_SYMBOL(__kunmap_atomic);
|
|
|
|
void *kmap_atomic_pfn(unsigned long pfn)
|
|
{
|
|
unsigned long vaddr;
|
|
int idx, type;
|
|
struct page *page = pfn_to_page(pfn);
|
|
|
|
preempt_disable();
|
|
pagefault_disable();
|
|
if (!PageHighMem(page))
|
|
return page_address(page);
|
|
|
|
type = kmap_atomic_idx_push();
|
|
idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
|
|
vaddr = __fix_to_virt(idx);
|
|
#ifdef CONFIG_DEBUG_HIGHMEM
|
|
BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
|
|
#endif
|
|
set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
|
|
|
|
return (void *)vaddr;
|
|
}
|