WSL2-Linux-Kernel/arch/sh/mm/pg-sh4.c

130 строки
3.0 KiB
C

/*
* 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 <linux/highmem.h>
#include <linux/module.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);
clear_page(to);
if ((((address & PAGE_MASK) ^ (unsigned long)to) & CACHE_ALIAS))
__flush_wback_region(to, PAGE_SIZE);
}
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
void *vto;
__set_bit(PG_mapped, &page->flags);
vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
memcpy(vto, src, len);
kunmap_coherent(vto);
if (vma->vm_flags & VM_EXEC)
flush_cache_page(vma, vaddr, page_to_pfn(page));
}
void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
void *vfrom;
__set_bit(PG_mapped, &page->flags);
vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
memcpy(dst, vfrom, len);
kunmap_coherent(vfrom);
}
void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
void *vfrom, *vto;
__set_bit(PG_mapped, &to->flags);
vto = kmap_atomic(to, KM_USER1);
vfrom = kmap_coherent(from, vaddr);
copy_page(vto, vfrom);
kunmap_coherent(vfrom);
if (((vaddr ^ (unsigned long)vto) & CACHE_ALIAS))
__flush_wback_region(vto, PAGE_SIZE);
kunmap_atomic(vto, KM_USER1);
/* Make sure this page is cleared on other CPU's too before using it */
smp_wmb();
}
EXPORT_SYMBOL(copy_user_highpage);
/*
* 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;
}