mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-22 20:23:57 +08:00
4368902bb9
Implement ioremap_prot() to allow mapping IO memory with variable protection via TLB. Implementing this allows the /dev/mem driver to use its generic access() VMA callback, which in turn allows ptrace to examine data in memory mapped regions mapped via /dev/mem, such as Arc DCCM. The end result is that it is possible to examine values of variables placed into DCCM in user space programs via GDB. CC: Alexey Brodkin <Alexey.Brodkin@synopsys.com> CC: Noam Camus <noamc@ezchip.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
92 lines
2.3 KiB
C
92 lines
2.3 KiB
C
/*
|
|
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/io.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <asm/cache.h>
|
|
|
|
void __iomem *ioremap(unsigned long paddr, unsigned long size)
|
|
{
|
|
unsigned long end;
|
|
|
|
/* Don't allow wraparound or zero size */
|
|
end = paddr + size - 1;
|
|
if (!size || (end < paddr))
|
|
return NULL;
|
|
|
|
/* If the region is h/w uncached, avoid MMU mappings */
|
|
if (paddr >= ARC_UNCACHED_ADDR_SPACE)
|
|
return (void __iomem *)paddr;
|
|
|
|
return ioremap_prot(paddr, size, PAGE_KERNEL_NO_CACHE);
|
|
}
|
|
EXPORT_SYMBOL(ioremap);
|
|
|
|
/*
|
|
* ioremap with access flags
|
|
* Cache semantics wise it is same as ioremap - "forced" uncached.
|
|
* However unline vanilla ioremap which bypasses ARC MMU for addresses in
|
|
* ARC hardware uncached region, this one still goes thru the MMU as caller
|
|
* might need finer access control (R/W/X)
|
|
*/
|
|
void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
|
|
unsigned long flags)
|
|
{
|
|
void __iomem *vaddr;
|
|
struct vm_struct *area;
|
|
unsigned long off, end;
|
|
pgprot_t prot = __pgprot(flags);
|
|
|
|
/* Don't allow wraparound, zero size */
|
|
end = paddr + size - 1;
|
|
if ((!size) || (end < paddr))
|
|
return NULL;
|
|
|
|
/* An early platform driver might end up here */
|
|
if (!slab_is_available())
|
|
return NULL;
|
|
|
|
/* force uncached */
|
|
prot = pgprot_noncached(prot);
|
|
|
|
/* Mappings have to be page-aligned */
|
|
off = paddr & ~PAGE_MASK;
|
|
paddr &= PAGE_MASK;
|
|
size = PAGE_ALIGN(end + 1) - paddr;
|
|
|
|
/*
|
|
* Ok, go for it..
|
|
*/
|
|
area = get_vm_area(size, VM_IOREMAP);
|
|
if (!area)
|
|
return NULL;
|
|
area->phys_addr = paddr;
|
|
vaddr = (void __iomem *)area->addr;
|
|
if (ioremap_page_range((unsigned long)vaddr,
|
|
(unsigned long)vaddr + size, paddr, prot)) {
|
|
vunmap((void __force *)vaddr);
|
|
return NULL;
|
|
}
|
|
return (void __iomem *)(off + (char __iomem *)vaddr);
|
|
}
|
|
EXPORT_SYMBOL(ioremap_prot);
|
|
|
|
|
|
void iounmap(const void __iomem *addr)
|
|
{
|
|
if (addr >= (void __force __iomem *)ARC_UNCACHED_ADDR_SPACE)
|
|
return;
|
|
|
|
vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
|
|
}
|
|
EXPORT_SYMBOL(iounmap);
|