mirror of
https://github.com/torvalds/linux.git
synced 2024-12-30 14:52:05 +00:00
18e780b4e6
Add special hook for architecture to verify addr, size or prot
when ioremap() or iounmap(), which will make the generic ioremap
more useful.
ioremap_allowed() return a bool,
- true means continue to remap
- false means skip remap and return directly
iounmap_allowed() return a bool,
- true means continue to vunmap
- false code means skip vunmap and return directly
Meanwhile, only vunmap the address when it is in vmalloc area
as the generic ioremap only returns vmalloc addresses.
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/20220607125027.44946-5-wangkefeng.wang@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
62 lines
1.4 KiB
C
62 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Re-map IO memory to kernel address space so that we can access it.
|
|
* This is needed for high PCI addresses that aren't mapped in the
|
|
* 640k-1MB IO memory area on PC's
|
|
*
|
|
* (C) Copyright 1995 1996 Linus Torvalds
|
|
*/
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/io.h>
|
|
#include <linux/export.h>
|
|
|
|
void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
|
|
unsigned long prot)
|
|
{
|
|
unsigned long offset, vaddr;
|
|
phys_addr_t last_addr;
|
|
struct vm_struct *area;
|
|
|
|
/* Disallow wrap-around or zero size */
|
|
last_addr = phys_addr + size - 1;
|
|
if (!size || last_addr < phys_addr)
|
|
return NULL;
|
|
|
|
/* Page-align mappings */
|
|
offset = phys_addr & (~PAGE_MASK);
|
|
phys_addr -= offset;
|
|
size = PAGE_ALIGN(size + offset);
|
|
|
|
if (!ioremap_allowed(phys_addr, size, prot))
|
|
return NULL;
|
|
|
|
area = get_vm_area_caller(size, VM_IOREMAP,
|
|
__builtin_return_address(0));
|
|
if (!area)
|
|
return NULL;
|
|
vaddr = (unsigned long)area->addr;
|
|
area->phys_addr = phys_addr;
|
|
|
|
if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
|
|
__pgprot(prot))) {
|
|
free_vm_area(area);
|
|
return NULL;
|
|
}
|
|
|
|
return (void __iomem *)(vaddr + offset);
|
|
}
|
|
EXPORT_SYMBOL(ioremap_prot);
|
|
|
|
void iounmap(volatile void __iomem *addr)
|
|
{
|
|
void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
|
|
|
|
if (!iounmap_allowed(vaddr))
|
|
return;
|
|
|
|
if (is_vmalloc_addr(vaddr))
|
|
vunmap(vaddr);
|
|
}
|
|
EXPORT_SYMBOL(iounmap);
|