mirror of https://gitee.com/openkylin/linux.git
401 lines
9.9 KiB
C
401 lines
9.9 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 <asm/cacheflush.h>
|
|
#include <asm/io.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/sizes.h>
|
|
|
|
/*
|
|
* Used by ioremap() and iounmap() code to mark (super)section-mapped
|
|
* I/O regions in vm_struct->flags field.
|
|
*/
|
|
#define VM_ARM_SECTION_MAPPING 0x80000000
|
|
|
|
static inline void
|
|
remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
|
|
unsigned long phys_addr, pgprot_t pgprot)
|
|
{
|
|
unsigned long end;
|
|
|
|
address &= ~PMD_MASK;
|
|
end = address + size;
|
|
if (end > PMD_SIZE)
|
|
end = PMD_SIZE;
|
|
BUG_ON(address >= end);
|
|
do {
|
|
if (!pte_none(*pte))
|
|
goto bad;
|
|
|
|
set_pte(pte, pfn_pte(phys_addr >> PAGE_SHIFT, pgprot));
|
|
address += PAGE_SIZE;
|
|
phys_addr += PAGE_SIZE;
|
|
pte++;
|
|
} while (address && (address < end));
|
|
return;
|
|
|
|
bad:
|
|
printk("remap_area_pte: page already exists\n");
|
|
BUG();
|
|
}
|
|
|
|
static inline int
|
|
remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
|
|
unsigned long phys_addr, unsigned long flags)
|
|
{
|
|
unsigned long end;
|
|
pgprot_t pgprot;
|
|
|
|
address &= ~PGDIR_MASK;
|
|
end = address + size;
|
|
|
|
if (end > PGDIR_SIZE)
|
|
end = PGDIR_SIZE;
|
|
|
|
phys_addr -= address;
|
|
BUG_ON(address >= end);
|
|
|
|
pgprot = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_WRITE | flags);
|
|
do {
|
|
pte_t * pte = pte_alloc_kernel(pmd, address);
|
|
if (!pte)
|
|
return -ENOMEM;
|
|
remap_area_pte(pte, address, end - address, address + phys_addr, pgprot);
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
pmd++;
|
|
} while (address && (address < end));
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
remap_area_pages(unsigned long start, unsigned long pfn,
|
|
unsigned long size, unsigned long flags)
|
|
{
|
|
unsigned long address = start;
|
|
unsigned long end = start + size;
|
|
unsigned long phys_addr = __pfn_to_phys(pfn);
|
|
int err = 0;
|
|
pgd_t * dir;
|
|
|
|
phys_addr -= address;
|
|
dir = pgd_offset(&init_mm, address);
|
|
BUG_ON(address >= end);
|
|
do {
|
|
pmd_t *pmd = pmd_alloc(&init_mm, dir, address);
|
|
if (!pmd) {
|
|
err = -ENOMEM;
|
|
break;
|
|
}
|
|
if (remap_area_pmd(pmd, address, end - address,
|
|
phys_addr + address, flags)) {
|
|
err = -ENOMEM;
|
|
break;
|
|
}
|
|
|
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
|
dir++;
|
|
} while (address && (address < end));
|
|
|
|
return err;
|
|
}
|
|
|
|
|
|
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);
|
|
}
|
|
|
|
#ifndef CONFIG_SMP
|
|
/*
|
|
* 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() 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);
|
|
pgd_t *pgd;
|
|
|
|
flush_cache_vunmap(addr, end);
|
|
pgd = pgd_offset_k(addr);
|
|
do {
|
|
pmd_t pmd, *pmdp = pmd_offset(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);
|
|
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(pmd_page_vaddr(pmd));
|
|
}
|
|
|
|
addr += PGDIR_SIZE;
|
|
pgd++;
|
|
} 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,
|
|
unsigned long size, unsigned long flags)
|
|
{
|
|
unsigned long prot, 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);
|
|
|
|
prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_DOMAIN(DOMAIN_IO) |
|
|
(flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE));
|
|
|
|
/*
|
|
* ARMv6 and above need XN set to prevent speculative prefetches
|
|
* hitting IO.
|
|
*/
|
|
if (cpu_architecture() >= CPU_ARCH_ARMv6)
|
|
prot |= PMD_SECT_XN;
|
|
|
|
pgd = pgd_offset_k(addr);
|
|
do {
|
|
pmd_t *pmd = pmd_offset(pgd, addr);
|
|
|
|
pmd[0] = __pmd(__pfn_to_phys(pfn) | prot);
|
|
pfn += SZ_1M >> PAGE_SHIFT;
|
|
pmd[1] = __pmd(__pfn_to_phys(pfn) | prot);
|
|
pfn += SZ_1M >> PAGE_SHIFT;
|
|
flush_pmd_entry(pmd);
|
|
|
|
addr += PGDIR_SIZE;
|
|
pgd++;
|
|
} while (addr < end);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
remap_area_supersections(unsigned long virt, unsigned long pfn,
|
|
unsigned long size, unsigned long flags)
|
|
{
|
|
unsigned long prot, 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);
|
|
|
|
prot = PMD_TYPE_SECT | PMD_SECT_SUPER | PMD_SECT_AP_WRITE |
|
|
PMD_DOMAIN(DOMAIN_IO) |
|
|
(flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE));
|
|
|
|
/*
|
|
* ARMv6 and above need XN set to prevent speculative prefetches
|
|
* hitting IO.
|
|
*/
|
|
if (cpu_architecture() >= CPU_ARCH_ARMv6)
|
|
prot |= PMD_SECT_XN;
|
|
|
|
pgd = pgd_offset_k(virt);
|
|
do {
|
|
unsigned long super_pmd_val, i;
|
|
|
|
super_pmd_val = __pfn_to_phys(pfn) | prot;
|
|
super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
pmd_t *pmd = pmd_offset(pgd, addr);
|
|
|
|
pmd[0] = __pmd(super_pmd_val);
|
|
pmd[1] = __pmd(super_pmd_val);
|
|
flush_pmd_entry(pmd);
|
|
|
|
addr += PGDIR_SIZE;
|
|
pgd++;
|
|
}
|
|
|
|
pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
|
|
} while (addr < end);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* 'flags' are the extra L_PTE_ flags that you want to specify for this
|
|
* mapping. See include/asm-arm/proc-armv/pgtable.h for more information.
|
|
*/
|
|
void __iomem *
|
|
__ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
|
|
unsigned long flags)
|
|
{
|
|
int err;
|
|
unsigned long addr;
|
|
struct vm_struct * area;
|
|
|
|
/*
|
|
* High mappings must be supersection aligned
|
|
*/
|
|
if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
|
|
return NULL;
|
|
|
|
area = get_vm_area(size, VM_IOREMAP);
|
|
if (!area)
|
|
return NULL;
|
|
addr = (unsigned long)area->addr;
|
|
|
|
#ifndef CONFIG_SMP
|
|
if ((((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
|
|
cpu_is_xsc3()) &&
|
|
!((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
|
|
area->flags |= VM_ARM_SECTION_MAPPING;
|
|
err = remap_area_supersections(addr, pfn, size, flags);
|
|
} else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
|
|
area->flags |= VM_ARM_SECTION_MAPPING;
|
|
err = remap_area_sections(addr, pfn, size, flags);
|
|
} else
|
|
#endif
|
|
err = remap_area_pages(addr, pfn, size, flags);
|
|
|
|
if (err) {
|
|
vunmap((void *)addr);
|
|
return NULL;
|
|
}
|
|
|
|
flush_cache_vmap(addr, addr + size);
|
|
return (void __iomem *) (offset + addr);
|
|
}
|
|
EXPORT_SYMBOL(__ioremap_pfn);
|
|
|
|
void __iomem *
|
|
__ioremap(unsigned long phys_addr, size_t size, unsigned long flags)
|
|
{
|
|
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;
|
|
|
|
/*
|
|
* Page align the mapping size
|
|
*/
|
|
size = PAGE_ALIGN(last_addr + 1) - phys_addr;
|
|
|
|
return __ioremap_pfn(pfn, offset, size, flags);
|
|
}
|
|
EXPORT_SYMBOL(__ioremap);
|
|
|
|
void __iounmap(volatile void __iomem *addr)
|
|
{
|
|
#ifndef CONFIG_SMP
|
|
struct vm_struct **p, *tmp;
|
|
#endif
|
|
unsigned int section_mapping = 0;
|
|
|
|
addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long)addr);
|
|
|
|
#ifndef CONFIG_SMP
|
|
/*
|
|
* If this is a section based mapping we need to handle it
|
|
* specially as the VM subysystem 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.
|
|
*/
|
|
write_lock(&vmlist_lock);
|
|
for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) {
|
|
if((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) {
|
|
if (tmp->flags & VM_ARM_SECTION_MAPPING) {
|
|
*p = tmp->next;
|
|
unmap_area_sections((unsigned long)tmp->addr,
|
|
tmp->size);
|
|
kfree(tmp);
|
|
section_mapping = 1;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
write_unlock(&vmlist_lock);
|
|
#endif
|
|
|
|
if (!section_mapping)
|
|
vunmap((void __force *)addr);
|
|
}
|
|
EXPORT_SYMBOL(__iounmap);
|