linux/arch/nds32/mm/ioremap.c
Greentime Hu 4a64f68dbd nds32: Device specific operations
This patch introduces ioremap implementations.

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 10:44:32 +08:00

63 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/vmalloc.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <asm/pgtable.h>
void __iomem *ioremap(phys_addr_t phys_addr, size_t size);
static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
void *caller)
{
struct vm_struct *area;
unsigned long addr, offset, last_addr;
pgprot_t prot;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* Mappings have to be page-aligned
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr + 1) - phys_addr;
/*
* Ok, go for it..
*/
area = get_vm_area_caller(size, VM_IOREMAP, caller);
if (!area)
return NULL;
area->phys_addr = phys_addr;
addr = (unsigned long)area->addr;
prot = __pgprot(_PAGE_V | _PAGE_M_KRW | _PAGE_D |
_PAGE_G | _PAGE_C_DEV);
if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
vunmap((void *)addr);
return NULL;
}
return (__force void __iomem *)(offset + (char *)addr);
}
void __iomem *ioremap(phys_addr_t phys_addr, size_t size)
{
return __ioremap_caller(phys_addr, size,
__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap);
void iounmap(volatile void __iomem * addr)
{
vunmap((void *)(PAGE_MASK & (unsigned long)addr));
}
EXPORT_SYMBOL(iounmap);