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linux-next/arch/nds32/mm/highmem.c
Greentime Hu 59fd53cd5c nds32: MMU initialization
This patch includes memory initializations and highmem supporting.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2018-02-22 10:44:31 +08:00

80 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/export.h>
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/bootmem.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
void *kmap(struct page *page)
{
unsigned long vaddr;
might_sleep();
if (!PageHighMem(page))
return page_address(page);
vaddr = (unsigned long)kmap_high(page);
return (void *)vaddr;
}
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, pte;
int type;
pte_t *ptep;
preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
pte = (page_to_pfn(page) << PAGE_SHIFT) | (PAGE_KERNEL);
ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
set_pte(ptep, pte);
__nds32__tlbop_inv(vaddr);
__nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
__nds32__tlbop_rwr(pte);
__nds32__isb();
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic);
void __kunmap_atomic(void *kvaddr)
{
if (kvaddr >= (void *)FIXADDR_START) {
unsigned long vaddr = (unsigned long)kvaddr;
pte_t *ptep;
kmap_atomic_idx_pop();
__nds32__tlbop_inv(vaddr);
__nds32__isb();
ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
set_pte(ptep, 0);
}
pagefault_enable();
preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);