linux/arch/sh/mm/pg-sh4.c

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/*
* arch/sh/mm/pg-sh4.c
*
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
* Copyright (C) 2002 - 2007 Paul Mundt
*
* Released under the terms of the GNU GPL v2.0.
*/
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
#define CACHE_ALIAS (current_cpu_data.dcache.alias_mask)
static inline void *kmap_coherent(struct page *page, unsigned long addr)
{
enum fixed_addresses idx;
unsigned long vaddr, flags;
pte_t pte;
inc_preempt_count();
idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
vaddr = __fix_to_virt(FIX_CMAP_END - idx);
pte = mk_pte(page, PAGE_KERNEL);
local_irq_save(flags);
flush_tlb_one(get_asid(), vaddr);
local_irq_restore(flags);
update_mmu_cache(NULL, vaddr, pte);
return (void *)vaddr;
}
static inline void kunmap_coherent(struct page *page)
{
dec_preempt_count();
preempt_check_resched();
}
/*
* clear_user_page
* @to: P1 address
* @address: U0 address to be mapped
* @page: page (virt_to_page(to))
*/
void clear_user_page(void *to, unsigned long address, struct page *page)
{
__set_bit(PG_mapped, &page->flags);
if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
clear_page(to);
else {
void *vto = kmap_coherent(page, address);
__clear_user_page(vto, to);
kunmap_coherent(vto);
}
}
/*
* copy_user_page
* @to: P1 address
* @from: P1 address
* @address: U0 address to be mapped
* @page: page (virt_to_page(to))
*/
void copy_user_page(void *to, void *from, unsigned long address,
struct page *page)
{
__set_bit(PG_mapped, &page->flags);
if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
copy_page(to, from);
else {
void *vfrom = kmap_coherent(page, address);
__copy_user_page(vfrom, from, to);
kunmap_coherent(vfrom);
}
}
/*
* For SH-4, we have our own implementation for ptep_get_and_clear
*/
inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
pte_t pte = *ptep;
pte_clear(mm, addr, ptep);
if (!pte_not_present(pte)) {
unsigned long pfn = pte_pfn(pte);
if (pfn_valid(pfn)) {
struct page *page = pfn_to_page(pfn);
struct address_space *mapping = page_mapping(page);
if (!mapping || !mapping_writably_mapped(mapping))
__clear_bit(PG_mapped, &page->flags);
}
}
return pte;
}