linux/arch/arm/mm/ioremap.c
Linus Torvalds 0e51793e16 Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King:
 "This is the first chunk of ARM updates for this merge window.
  Conflicts are expected in two files - asm/timex.h and
  mach-integrator/integrator_cp.c.  Nothing particularly stands out more
  than anything else.

  Most of the growth is down to the opcodes stuff from Dave Martin,
  which is countered by Rob's patches to use more of the asm-generic
  headers on ARM."

(A few more conflicts grew since then, but it all looked fairly trivial)

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (44 commits)
  ARM: 7548/1: include linux/sched.h in syscall.h
  ARM: 7541/1: Add ARM ERRATA 775420 workaround
  ARM: ensure vm_struct has its phys_addr member filled in
  ARM: 7540/1: kexec: Check segment memory addresses
  ARM: 7539/1: kexec: scan for dtb magic in segments
  ARM: 7538/1: delay: add registration mechanism for delay timer sources
  ARM: 7536/1: smp: Formalize an IPI for wakeup
  ARM: 7525/1: ptrace: use updated syscall number for syscall auditing
  ARM: 7524/1: support syscall tracing
  ARM: 7519/1: integrator: convert platform devices to Device Tree
  ARM: 7518/1: integrator: convert AMBA devices to device tree
  ARM: 7517/1: integrator: initial device tree support
  ARM: 7516/1: plat-versatile: add DT support to FPGA IRQ
  ARM: 7515/1: integrator: check PL010 base address from resource
  ARM: 7514/1: integrator: call common init function from machine
  ARM: 7522/1: arch_timers: register a time/cycle counter
  ARM: 7523/1: arch_timers: enable the use of the virtual timer
  ARM: 7531/1: mark kernelmode mem{cpy,set} non-experimental
  ARM: 7520/1: Build dtb files in all target
  ARM: Fix build warning in arch/arm/mm/alignment.c
  ...
2012-10-07 21:20:57 +09:00

401 lines
10 KiB
C

/*
* linux/arch/arm/mm/ioremap.c
*
* Re-map IO memory to kernel address space so that we can access it.
*
* (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
*
* 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 the ARM 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 <linux/sizes.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/system_info.h>
#include <asm/mach/map.h>
#include <asm/mach/pci.h>
#include "mm.h"
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);
void __check_kvm_seq(struct mm_struct *mm)
{
unsigned int seq;
do {
seq = init_mm.context.kvm_seq;
memcpy(pgd_offset(mm, VMALLOC_START),
pgd_offset_k(VMALLOC_START),
sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
pgd_index(VMALLOC_START)));
mm->context.kvm_seq = seq;
} while (seq != init_mm.context.kvm_seq);
}
#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
/*
* 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 1MB 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_1M - 1));
pgd_t *pgd;
pud_t *pud;
pmd_t *pmdp;
flush_cache_vunmap(addr, end);
pgd = pgd_offset_k(addr);
pud = pud_offset(pgd, addr);
pmdp = pmd_offset(pud, addr);
do {
pmd_t 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);
init_mm.context.kvm_seq++;
/*
* 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 += PMD_SIZE;
pmdp += 2;
} while (addr < end);
/*
* Ensure that the active_mm is up to date - we want to
* catch any use-after-iounmap cases.
*/
if (current->active_mm->context.kvm_seq != init_mm.context.kvm_seq)
__check_kvm_seq(current->active_mm);
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;
pud_t *pud;
pmd_t *pmd;
/*
* Remove and free any PTE-based mapping, and
* sync the current kernel mapping.
*/
unmap_area_sections(virt, size);
pgd = pgd_offset_k(addr);
pud = pud_offset(pgd, addr);
pmd = pmd_offset(pud, addr);
do {
pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
pfn += SZ_1M >> PAGE_SHIFT;
pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
pfn += SZ_1M >> PAGE_SHIFT;
flush_pmd_entry(pmd);
addr += PMD_SIZE;
pmd += 2;
} while (addr < end);
return 0;
}
static int
remap_area_supersections(unsigned long virt, unsigned long pfn,
size_t size, const struct mem_type *type)
{
unsigned long addr = virt, end = virt + size;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
/*
* Remove and free any PTE-based mapping, and
* sync the current kernel mapping.
*/
unmap_area_sections(virt, size);
pgd = pgd_offset_k(virt);
pud = pud_offset(pgd, addr);
pmd = pmd_offset(pud, addr);
do {
unsigned long super_pmd_val, i;
super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect |
PMD_SECT_SUPER;
super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
for (i = 0; i < 8; i++) {
pmd[0] = __pmd(super_pmd_val);
pmd[1] = __pmd(super_pmd_val);
flush_pmd_entry(pmd);
addr += PMD_SIZE;
pmd += 2;
}
pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
} while (addr < end);
return 0;
}
#endif
void __iomem * __arm_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;
#ifndef CONFIG_ARM_LPAE
/*
* High mappings must be supersection aligned
*/
if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
return NULL;
#endif
type = get_mem_type(mtype);
if (!type)
return NULL;
/*
* Page align the mapping size, taking account of any offset.
*/
size = PAGE_ALIGN(offset + size);
/*
* Try to reuse one of the static mapping whenever possible.
*/
read_lock(&vmlist_lock);
for (area = vmlist; area; area = area->next) {
if (!size || (sizeof(phys_addr_t) == 4 && pfn >= 0x100000))
break;
if (!(area->flags & VM_ARM_STATIC_MAPPING))
continue;
if ((area->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
continue;
if (__phys_to_pfn(area->phys_addr) > pfn ||
__pfn_to_phys(pfn) + size-1 > area->phys_addr + area->size-1)
continue;
/* we can drop the lock here as we know *area is static */
read_unlock(&vmlist_lock);
addr = (unsigned long)area->addr;
addr += __pfn_to_phys(pfn) - area->phys_addr;
return (void __iomem *) (offset + addr);
}
read_unlock(&vmlist_lock);
/*
* Don't allow RAM to be mapped - this causes problems with ARMv6+
*/
if (WARN_ON(pfn_valid(pfn)))
return NULL;
area = get_vm_area_caller(size, VM_IOREMAP, caller);
if (!area)
return NULL;
addr = (unsigned long)area->addr;
area->phys_addr = __pfn_to_phys(pfn);
#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
if (DOMAIN_IO == 0 &&
(((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
cpu_is_xsc3()) && pfn >= 0x100000 &&
!((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
area->flags |= VM_ARM_SECTION_MAPPING;
err = remap_area_supersections(addr, pfn, size, type);
} else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
area->flags |= VM_ARM_SECTION_MAPPING;
err = remap_area_sections(addr, pfn, size, type);
} else
#endif
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 *__arm_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 __arm_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 *
__arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
unsigned int mtype)
{
return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
__builtin_return_address(0));
}
EXPORT_SYMBOL(__arm_ioremap_pfn);
void __iomem * (*arch_ioremap_caller)(unsigned long, size_t,
unsigned int, void *) =
__arm_ioremap_caller;
void __iomem *
__arm_ioremap(unsigned long phys_addr, size_t size, unsigned int mtype)
{
return arch_ioremap_caller(phys_addr, size, mtype,
__builtin_return_address(0));
}
EXPORT_SYMBOL(__arm_ioremap);
/*
* Remap an arbitrary physical address space into the kernel virtual
* address space as memory. Needed when the kernel wants to execute
* code in external memory. This is needed for reprogramming source
* clocks that would affect normal memory for example. Please see
* CONFIG_GENERIC_ALLOCATOR for allocating external memory.
*/
void __iomem *
__arm_ioremap_exec(unsigned long phys_addr, size_t size, bool cached)
{
unsigned int mtype;
if (cached)
mtype = MT_MEMORY;
else
mtype = MT_MEMORY_NONCACHED;
return __arm_ioremap_caller(phys_addr, size, mtype,
__builtin_return_address(0));
}
void __iounmap(volatile void __iomem *io_addr)
{
void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
struct vm_struct *vm;
read_lock(&vmlist_lock);
for (vm = vmlist; vm; vm = vm->next) {
if (vm->addr > addr)
break;
if (!(vm->flags & VM_IOREMAP))
continue;
/* If this is a static mapping we must leave it alone */
if ((vm->flags & VM_ARM_STATIC_MAPPING) &&
(vm->addr <= addr) && (vm->addr + vm->size > addr)) {
read_unlock(&vmlist_lock);
return;
}
#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
/*
* 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.
*/
if ((vm->addr == addr) &&
(vm->flags & VM_ARM_SECTION_MAPPING)) {
unmap_area_sections((unsigned long)vm->addr, vm->size);
break;
}
#endif
}
read_unlock(&vmlist_lock);
vunmap(addr);
}
void (*arch_iounmap)(volatile void __iomem *) = __iounmap;
void __arm_iounmap(volatile void __iomem *io_addr)
{
arch_iounmap(io_addr);
}
EXPORT_SYMBOL(__arm_iounmap);
#ifdef CONFIG_PCI
int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
{
BUG_ON(offset + SZ_64K > IO_SPACE_LIMIT);
return ioremap_page_range(PCI_IO_VIRT_BASE + offset,
PCI_IO_VIRT_BASE + offset + SZ_64K,
phys_addr,
__pgprot(get_mem_type(MT_DEVICE)->prot_pte));
}
EXPORT_SYMBOL_GPL(pci_ioremap_io);
#endif