mirror of https://gitee.com/openkylin/linux.git
211 lines
5.0 KiB
C
211 lines
5.0 KiB
C
/*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*
|
|
* (C) Copyright 1995 1996 Linus Torvalds
|
|
* (C) Copyright 2001, 2002 Ralf Baechle
|
|
*/
|
|
#include <linux/export.h>
|
|
#include <asm/addrspace.h>
|
|
#include <asm/byteorder.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/mm_types.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/io.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
static inline void remap_area_pte(pte_t * pte, unsigned long address,
|
|
phys_addr_t size, phys_addr_t phys_addr, unsigned long flags)
|
|
{
|
|
phys_addr_t end;
|
|
unsigned long pfn;
|
|
pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE
|
|
| __WRITEABLE | flags);
|
|
|
|
address &= ~PMD_MASK;
|
|
end = address + size;
|
|
if (end > PMD_SIZE)
|
|
end = PMD_SIZE;
|
|
BUG_ON(address >= end);
|
|
pfn = phys_addr >> PAGE_SHIFT;
|
|
do {
|
|
if (!pte_none(*pte)) {
|
|
printk("remap_area_pte: page already exists\n");
|
|
BUG();
|
|
}
|
|
set_pte(pte, pfn_pte(pfn, pgprot));
|
|
address += PAGE_SIZE;
|
|
pfn++;
|
|
pte++;
|
|
} while (address && (address < end));
|
|
}
|
|
|
|
static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
|
|
phys_addr_t size, phys_addr_t phys_addr, unsigned long flags)
|
|
{
|
|
phys_addr_t end;
|
|
|
|
address &= ~PGDIR_MASK;
|
|
end = address + size;
|
|
if (end > PGDIR_SIZE)
|
|
end = PGDIR_SIZE;
|
|
phys_addr -= address;
|
|
BUG_ON(address >= end);
|
|
do {
|
|
pte_t * pte = pte_alloc_kernel(pmd, address);
|
|
if (!pte)
|
|
return -ENOMEM;
|
|
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
pmd++;
|
|
} while (address && (address < end));
|
|
return 0;
|
|
}
|
|
|
|
static int remap_area_pages(unsigned long address, phys_addr_t phys_addr,
|
|
phys_addr_t size, unsigned long flags)
|
|
{
|
|
int error;
|
|
pgd_t * dir;
|
|
unsigned long end = address + size;
|
|
|
|
phys_addr -= address;
|
|
dir = pgd_offset(&init_mm, address);
|
|
flush_cache_all();
|
|
BUG_ON(address >= end);
|
|
do {
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
|
|
error = -ENOMEM;
|
|
p4d = p4d_alloc(&init_mm, dir, address);
|
|
if (!p4d)
|
|
break;
|
|
pud = pud_alloc(&init_mm, p4d, address);
|
|
if (!pud)
|
|
break;
|
|
pmd = pmd_alloc(&init_mm, pud, address);
|
|
if (!pmd)
|
|
break;
|
|
if (remap_area_pmd(pmd, address, end - address,
|
|
phys_addr + address, flags))
|
|
break;
|
|
error = 0;
|
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
|
dir++;
|
|
} while (address && (address < end));
|
|
flush_tlb_all();
|
|
return error;
|
|
}
|
|
|
|
static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
|
|
void *arg)
|
|
{
|
|
unsigned long i;
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
if (pfn_valid(start_pfn + i) &&
|
|
!PageReserved(pfn_to_page(start_pfn + i)))
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Generic mapping function (not visible outside):
|
|
*/
|
|
|
|
/*
|
|
* Remap an arbitrary physical address space into the kernel virtual
|
|
* address space. Needed when the kernel wants to access high addresses
|
|
* directly.
|
|
*
|
|
* NOTE! We need to allow non-page-aligned mappings too: we will obviously
|
|
* have to convert them into an offset in a page-aligned mapping, but the
|
|
* caller shouldn't need to know that small detail.
|
|
*/
|
|
|
|
#define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
|
|
|
|
void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long flags)
|
|
{
|
|
unsigned long offset, pfn, last_pfn;
|
|
struct vm_struct * area;
|
|
phys_addr_t last_addr;
|
|
void * addr;
|
|
|
|
phys_addr = fixup_bigphys_addr(phys_addr, size);
|
|
|
|
/* Don't allow wraparound or zero size */
|
|
last_addr = phys_addr + size - 1;
|
|
if (!size || last_addr < phys_addr)
|
|
return NULL;
|
|
|
|
/*
|
|
* Map uncached objects in the low 512mb of address space using KSEG1,
|
|
* otherwise map using page tables.
|
|
*/
|
|
if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
|
|
flags == _CACHE_UNCACHED)
|
|
return (void __iomem *) CKSEG1ADDR(phys_addr);
|
|
|
|
/*
|
|
* Don't allow anybody to remap RAM that may be allocated by the page
|
|
* allocator, since that could lead to races & data clobbering.
|
|
*/
|
|
pfn = PFN_DOWN(phys_addr);
|
|
last_pfn = PFN_DOWN(last_addr);
|
|
if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
|
|
__ioremap_check_ram) == 1) {
|
|
WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
|
|
&phys_addr, &last_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(size, VM_IOREMAP);
|
|
if (!area)
|
|
return NULL;
|
|
addr = area->addr;
|
|
if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
|
|
vunmap(addr);
|
|
return NULL;
|
|
}
|
|
|
|
return (void __iomem *) (offset + (char *)addr);
|
|
}
|
|
|
|
#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
|
|
|
|
void __iounmap(const volatile void __iomem *addr)
|
|
{
|
|
struct vm_struct *p;
|
|
|
|
if (IS_KSEG1(addr))
|
|
return;
|
|
|
|
p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
|
|
if (!p)
|
|
printk(KERN_ERR "iounmap: bad address %p\n", addr);
|
|
|
|
kfree(p);
|
|
}
|
|
|
|
EXPORT_SYMBOL(__ioremap);
|
|
EXPORT_SYMBOL(__iounmap);
|