mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
fc47897d2c
This patch adds several definitions for device communication, including I/O accessors and ioremap(). The __raw_* accessors are implemented as inline asm to avoid compiler generation of post-indexed accesses (less efficient to emulate in a virtualised environment). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
84 lines
2.2 KiB
C
84 lines
2.2 KiB
C
/*
|
|
* Based on arch/arm/mm/ioremap.c
|
|
*
|
|
* (C) Copyright 1995 1996 Linus Torvalds
|
|
* Hacked for ARM by Phil Blundell <philb@gnu.org>
|
|
* Hacked to allow all architectures to build, and various cleanups
|
|
* by Russell King
|
|
* Copyright (C) 2012 ARM Ltd.
|
|
*
|
|
* 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.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <linux/export.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/io.h>
|
|
|
|
static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
|
|
pgprot_t prot, void *caller)
|
|
{
|
|
unsigned long last_addr;
|
|
unsigned long offset = phys_addr & ~PAGE_MASK;
|
|
int err;
|
|
unsigned long addr;
|
|
struct vm_struct *area;
|
|
|
|
/*
|
|
* Page align the mapping address and size, taking account of any
|
|
* offset.
|
|
*/
|
|
phys_addr &= PAGE_MASK;
|
|
size = PAGE_ALIGN(size + offset);
|
|
|
|
/*
|
|
* Don't allow wraparound, zero size or outside PHYS_MASK.
|
|
*/
|
|
last_addr = phys_addr + size - 1;
|
|
if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
|
|
return NULL;
|
|
|
|
/*
|
|
* Don't allow RAM to be mapped.
|
|
*/
|
|
if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
|
|
return NULL;
|
|
|
|
area = get_vm_area_caller(size, VM_IOREMAP, caller);
|
|
if (!area)
|
|
return NULL;
|
|
addr = (unsigned long)area->addr;
|
|
|
|
err = ioremap_page_range(addr, addr + size, phys_addr, prot);
|
|
if (err) {
|
|
vunmap((void *)addr);
|
|
return NULL;
|
|
}
|
|
|
|
return (void __iomem *)(offset + addr);
|
|
}
|
|
|
|
void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
|
|
{
|
|
return __ioremap_caller(phys_addr, size, prot,
|
|
__builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(__ioremap);
|
|
|
|
void __iounmap(volatile void __iomem *io_addr)
|
|
{
|
|
void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
|
|
|
|
vunmap(addr);
|
|
}
|
|
EXPORT_SYMBOL(__iounmap);
|