![Andrew Morton](/assets/img/avatar_default.png)
__uc32_ioremap_pfn_caller() should return NULL when the pfn is found to be invalid. From a recommendation by Guan Xuetao. Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
255 lines
6.8 KiB
C
255 lines
6.8 KiB
C
/*
|
|
* linux/arch/unicore32/mm/ioremap.c
|
|
*
|
|
* Code specific to PKUnity SoC and UniCore ISA
|
|
*
|
|
* Copyright (C) 2001-2010 GUAN Xue-tao
|
|
*
|
|
* 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.
|
|
*
|
|
*
|
|
* Re-map IO memory to kernel address space so that we can access it.
|
|
*
|
|
* This allows a driver to remap an arbitrary region of bus memory into
|
|
* virtual space. One should *only* use readl, writel, memcpy_toio and
|
|
* so on with such remapped areas.
|
|
*
|
|
* Because UniCore only has a 32-bit address space we can't address the
|
|
* whole of the (physical) PCI space at once. PCI huge-mode addressing
|
|
* allows us to circumvent this restriction by splitting PCI space into
|
|
* two 2GB chunks and mapping only one at a time into processor memory.
|
|
* We use MMU protection domains to trap any attempt to access the bank
|
|
* that is not currently mapped. (This isn't fully implemented yet.)
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/io.h>
|
|
|
|
#include <asm/cputype.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/sizes.h>
|
|
|
|
#include <mach/map.h>
|
|
#include "mm.h"
|
|
|
|
/*
|
|
* Used by ioremap() and iounmap() code to mark (super)section-mapped
|
|
* I/O regions in vm_struct->flags field.
|
|
*/
|
|
#define VM_UNICORE_SECTION_MAPPING 0x80000000
|
|
|
|
int ioremap_page(unsigned long virt, unsigned long phys,
|
|
const struct mem_type *mtype)
|
|
{
|
|
return ioremap_page_range(virt, virt + PAGE_SIZE, phys,
|
|
__pgprot(mtype->prot_pte));
|
|
}
|
|
EXPORT_SYMBOL(ioremap_page);
|
|
|
|
/*
|
|
* Section support is unsafe on SMP - If you iounmap and ioremap a region,
|
|
* the other CPUs will not see this change until their next context switch.
|
|
* Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
|
|
* which requires the new ioremap'd region to be referenced, the CPU will
|
|
* reference the _old_ region.
|
|
*
|
|
* Note that get_vm_area_caller() allocates a guard 4K page, so we need to
|
|
* mask the size back to 4MB aligned or we will overflow in the loop below.
|
|
*/
|
|
static void unmap_area_sections(unsigned long virt, unsigned long size)
|
|
{
|
|
unsigned long addr = virt, end = virt + (size & ~(SZ_4M - 1));
|
|
pgd_t *pgd;
|
|
|
|
flush_cache_vunmap(addr, end);
|
|
pgd = pgd_offset_k(addr);
|
|
do {
|
|
pmd_t pmd, *pmdp = pmd_offset((pud_t *)pgd, addr);
|
|
|
|
pmd = *pmdp;
|
|
if (!pmd_none(pmd)) {
|
|
/*
|
|
* Clear the PMD from the page table, and
|
|
* increment the kvm sequence so others
|
|
* notice this change.
|
|
*
|
|
* Note: this is still racy on SMP machines.
|
|
*/
|
|
pmd_clear(pmdp);
|
|
|
|
/*
|
|
* Free the page table, if there was one.
|
|
*/
|
|
if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
|
|
pte_free_kernel(&init_mm, pmd_page_vaddr(pmd));
|
|
}
|
|
|
|
addr += PGDIR_SIZE;
|
|
pgd++;
|
|
} while (addr < end);
|
|
|
|
flush_tlb_kernel_range(virt, end);
|
|
}
|
|
|
|
static int
|
|
remap_area_sections(unsigned long virt, unsigned long pfn,
|
|
size_t size, const struct mem_type *type)
|
|
{
|
|
unsigned long addr = virt, end = virt + size;
|
|
pgd_t *pgd;
|
|
|
|
/*
|
|
* Remove and free any PTE-based mapping, and
|
|
* sync the current kernel mapping.
|
|
*/
|
|
unmap_area_sections(virt, size);
|
|
|
|
pgd = pgd_offset_k(addr);
|
|
do {
|
|
pmd_t *pmd = pmd_offset((pud_t *)pgd, addr);
|
|
|
|
set_pmd(pmd, __pmd(__pfn_to_phys(pfn) | type->prot_sect));
|
|
pfn += SZ_4M >> PAGE_SHIFT;
|
|
flush_pmd_entry(pmd);
|
|
|
|
addr += PGDIR_SIZE;
|
|
pgd++;
|
|
} while (addr < end);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void __iomem *__uc32_ioremap_pfn_caller(unsigned long pfn,
|
|
unsigned long offset, size_t size, unsigned int mtype, void *caller)
|
|
{
|
|
const struct mem_type *type;
|
|
int err;
|
|
unsigned long addr;
|
|
struct vm_struct *area;
|
|
|
|
/*
|
|
* High mappings must be section aligned
|
|
*/
|
|
if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SECTION_MASK))
|
|
return NULL;
|
|
|
|
/*
|
|
* Don't allow RAM to be mapped
|
|
*/
|
|
if (pfn_valid(pfn)) {
|
|
WARN(1, "BUG: Your driver calls ioremap() on\n"
|
|
"system memory. This leads to architecturally\n"
|
|
"unpredictable behaviour, and ioremap() will fail in\n"
|
|
"the next kernel release. Please fix your driver.\n");
|
|
return NULL;
|
|
}
|
|
|
|
type = get_mem_type(mtype);
|
|
if (!type)
|
|
return NULL;
|
|
|
|
/*
|
|
* Page align the mapping size, taking account of any offset.
|
|
*/
|
|
size = PAGE_ALIGN(offset + size);
|
|
|
|
area = get_vm_area_caller(size, VM_IOREMAP, caller);
|
|
if (!area)
|
|
return NULL;
|
|
addr = (unsigned long)area->addr;
|
|
|
|
if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
|
|
area->flags |= VM_UNICORE_SECTION_MAPPING;
|
|
err = remap_area_sections(addr, pfn, size, type);
|
|
} else
|
|
err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn),
|
|
__pgprot(type->prot_pte));
|
|
|
|
if (err) {
|
|
vunmap((void *)addr);
|
|
return NULL;
|
|
}
|
|
|
|
flush_cache_vmap(addr, addr + size);
|
|
return (void __iomem *) (offset + addr);
|
|
}
|
|
|
|
void __iomem *__uc32_ioremap_caller(unsigned long phys_addr, size_t size,
|
|
unsigned int mtype, void *caller)
|
|
{
|
|
unsigned long last_addr;
|
|
unsigned long offset = phys_addr & ~PAGE_MASK;
|
|
unsigned long pfn = __phys_to_pfn(phys_addr);
|
|
|
|
/*
|
|
* Don't allow wraparound or zero size
|
|
*/
|
|
last_addr = phys_addr + size - 1;
|
|
if (!size || last_addr < phys_addr)
|
|
return NULL;
|
|
|
|
return __uc32_ioremap_pfn_caller(pfn, offset, size, mtype, caller);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
void __iomem *
|
|
__uc32_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
|
|
unsigned int mtype)
|
|
{
|
|
return __uc32_ioremap_pfn_caller(pfn, offset, size, mtype,
|
|
__builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(__uc32_ioremap_pfn);
|
|
|
|
void __iomem *
|
|
__uc32_ioremap(unsigned long phys_addr, size_t size)
|
|
{
|
|
return __uc32_ioremap_caller(phys_addr, size, MT_DEVICE,
|
|
__builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(__uc32_ioremap);
|
|
|
|
void __iomem *
|
|
__uc32_ioremap_cached(unsigned long phys_addr, size_t size)
|
|
{
|
|
return __uc32_ioremap_caller(phys_addr, size, MT_DEVICE_CACHED,
|
|
__builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(__uc32_ioremap_cached);
|
|
|
|
void __uc32_iounmap(volatile void __iomem *io_addr)
|
|
{
|
|
void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
|
|
struct vm_struct *vm;
|
|
|
|
/*
|
|
* If this is a section based mapping we need to handle it
|
|
* specially as the VM subsystem does not know how to handle
|
|
* such a beast. We need the lock here b/c we need to clear
|
|
* all the mappings before the area can be reclaimed
|
|
* by someone else.
|
|
*/
|
|
vm = find_vm_area(addr);
|
|
if (vm && (vm->flags & VM_IOREMAP) &&
|
|
(vm->flags & VM_UNICORE_SECTION_MAPPING))
|
|
unmap_area_sections((unsigned long)vm->addr, vm->size);
|
|
|
|
vunmap(addr);
|
|
}
|
|
EXPORT_SYMBOL(__uc32_iounmap);
|