// SPDX-License-Identifier: GPL-2.0-only
/*
* 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 <[email protected]>
* 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 <linux/memblock.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
#include <asm/cacheflush.h>
#include <asm/early_ioremap.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/set_memory.h>
#include <asm/system_info.h>
#include <asm/mach/map.h>
#include <asm/mach/pci.h>
#include "mm.h"
LIST_HEAD(static_vmlist);
static struct static_vm *find_static_vm_paddr(phys_addr_t paddr,
size_t size, unsigned int mtype)
{
struct static_vm *svm;
struct vm_struct *vm;
list_for_each_entry(svm, &static_vmlist, list) {
vm = &svm->vm;
if (!(vm->flags & VM_ARM_STATIC_MAPPING))
continue;
if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
continue;
if (vm->phys_addr > paddr ||
paddr + size - 1 > vm->phys_addr + vm->size - 1)
continue;
return svm;
}
return NULL;
}
struct static_vm *find_static_vm_vaddr(void *vaddr)
{
struct static_vm *svm;
struct vm_struct *vm;
list_for_each_entry(svm, &static_vmlist, list) {
vm = &svm->vm;
/* static_vmlist is ascending order */
if (vm->addr > vaddr)
break;
if (vm->addr <= vaddr && vm->addr + vm->size > vaddr)
return svm;
}
return NULL;
}
void __init add_static_vm_early(struct static_vm *svm)
{
struct static_vm *curr_svm;
struct vm_struct *vm;
void *vaddr;
vm = &svm->vm;
vm_area_add_early(vm);
vaddr = vm->addr;
list_for_each_entry(curr_svm, &static_vmlist, list) {
vm = &curr_svm->vm;
if (vm->addr > vaddr)
break;
}
list_add_tail(&svm->list, &curr_svm->list);
}
int ioremap_page(unsigned long virt, unsigned long phys,
const struct mem_type *mtype)
{
return vmap_page_range(virt, virt + PAGE_SIZE, phys,
__pgprot(mtype->prot_pte));
}
EXPORT_SYMBOL(ioremap_page);
void __check_vmalloc_seq(struct mm_struct *mm)
{
int seq;
do {
seq = atomic_read(&init_mm.context.vmalloc_seq);
memcpy(pgd_offset(mm, VMALLOC_START),
pgd_offset_k(VMALLOC_START),
sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
pgd_index(VMALLOC_START)));
/*
* Use a store-release so that other CPUs that observe the
* counter's new value are guaranteed to see the results of the
* memcpy as well.
*/
atomic_set_release(&mm->context.vmalloc_seq, seq);
} while (seq != atomic_read(&init_mm.context.vmalloc_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));
pmd_t *pmdp = pmd_off_k(addr);
do {
pmd_t pmd = *pmdp;
if (!pmd_none(pmd)) {
/*
* Clear the PMD from the page table, and
* increment the vmalloc sequence so others
* notice this change.
*
* Note: this is still racy on SMP machines.
*/
pmd_clear(pmdp);
atomic_inc_return_release(&init_mm.context.vmalloc_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.
*/
check_vmalloc_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;
pmd_t *pmd = pmd_off_k(addr);
/*
* Remove and free any PTE-based mapping, and
* sync the current kernel mapping.
*/
unmap_area_sections(virt, size);
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;
pmd_t *pmd = pmd_off_k(addr);
/*
* Remove and free any PTE-based mapping, and
* sync the current kernel mapping.
*/
unmap_area_sections(virt, size);
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
static 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;
phys_addr_t paddr = __pfn_to_phys(pfn);
#ifndef CONFIG_ARM_LPAE
/*
* High mappings must be supersection aligned
*/
if (pfn >= 0x100000 && (paddr & ~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.
*/
if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) {
struct static_vm *svm;
svm = find_static_vm_paddr(paddr, size, mtype);
if (svm) {
addr = (unsigned long)svm->vm.addr;
addr += paddr - svm->vm.phys_addr;
return (void __iomem *) (offset + addr);
}
}
/*
* Don't allow RAM to be mapped with mismatched attributes - this
* causes problems with ARMv6+
*/
if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) &&
mtype != MT_MEMORY_RW))
return NULL;
area = get_vm_area_caller(size, VM_IOREMAP, caller);
if (!area)
return NULL;
addr = (unsigned long)area->addr;
area->phys_addr = paddr;
#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 &&
!((paddr | size | addr) & ~SUPERSECTION_MASK)) {
area->flags |= VM_ARM_SECTION_MAPPING;
err = remap_area_supersections(addr, pfn, size, type);
} else if (!((paddr | 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, paddr,
__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(phys_addr_t phys_addr, size_t size,
unsigned int mtype, void *caller)
{
phys_addr_t 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)(phys_addr_t, size_t,
unsigned int, void *) =
__arm_ioremap_caller;
void __iomem *ioremap(resource_size_t res_cookie, size_t size)
{
return arch_ioremap_caller(res_cookie, size, MT_DEVICE,
__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap);
void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size)
{
return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED,
__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_cache);
void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size)
{
return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC,
__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_wc);
/*
* 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(phys_addr_t phys_addr, size_t size, bool cached)
{
unsigned int mtype;
if (cached)
mtype = MT_MEMORY_RWX;
else
mtype = MT_MEMORY_RWX_NONCACHED;
return __arm_ioremap_caller(phys_addr, size, mtype,
__builtin_return_address(0));
}
void __arm_iomem_set_ro(void __iomem *ptr, size_t size)
{
set_memory_ro((unsigned long)ptr, PAGE_ALIGN(size) / PAGE_SIZE);
}
void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
{
return (__force void *)arch_ioremap_caller(phys_addr, size,
MT_MEMORY_RW,
__builtin_return_address(0));
}
void iounmap(volatile void __iomem *io_addr)
{
void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
struct static_vm *svm;
/* If this is a static mapping, we must leave it alone */
svm = find_static_vm_vaddr(addr);
if (svm)
return;
#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
{
struct vm_struct *vm;
vm = find_vm_area(addr);
/*
* 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 && (vm->flags & VM_ARM_SECTION_MAPPING))
unmap_area_sections((unsigned long)vm->addr, vm->size);
}
#endif
vunmap(addr);
}
EXPORT_SYMBOL(iounmap);
#if defined(CONFIG_PCI) || IS_ENABLED(CONFIG_PCMCIA)
static int pci_ioremap_mem_type = MT_DEVICE;
void pci_ioremap_set_mem_type(int mem_type)
{
pci_ioremap_mem_type = mem_type;
}
int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
{
unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
if (!(res->flags & IORESOURCE_IO))
return -EINVAL;
if (res->end > IO_SPACE_LIMIT)
return -EINVAL;
return vmap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
__pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte));
}
EXPORT_SYMBOL(pci_remap_iospace);
void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size)
{
return arch_ioremap_caller(res_cookie, size, MT_UNCACHED,
__builtin_return_address(0));
}
EXPORT_SYMBOL_GPL(pci_remap_cfgspace);
#endif
/*
* Must be called after early_fixmap_init
*/
void __init early_ioremap_init(void)
{
early_ioremap_setup();
}
bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
unsigned long flags)
{
unsigned long pfn = PHYS_PFN(offset);
return memblock_is_map_memory(pfn);
}
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