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9ab9e4fce4
The generic memremap() falls back to using ioremap_cache() to create MEMREMAP_WB mappings if the requested region is not already covered by the linear mapping, unless the architecture provides an implementation of arch_memremap_wb(). Since ioremap_cache() is not appropriate on ARM to map memory with the same attributes used for the linear mapping, implement arch_memremap_wb() which does exactly that. Also, relax the WARN() check to allow MT_MEMORY_RW mappings of pfn_valid() pages. Cc: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
493 lines
12 KiB
C
493 lines
12 KiB
C
/*
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* linux/arch/arm/mm/ioremap.c
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*
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* Re-map IO memory to kernel address space so that we can access it.
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*
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* (C) Copyright 1995 1996 Linus Torvalds
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*
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* Hacked for ARM by Phil Blundell <philb@gnu.org>
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* Hacked to allow all architectures to build, and various cleanups
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* by Russell King
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*
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* This allows a driver to remap an arbitrary region of bus memory into
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* virtual space. One should *only* use readl, writel, memcpy_toio and
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* so on with such remapped areas.
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*
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* Because the ARM only has a 32-bit address space we can't address the
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* whole of the (physical) PCI space at once. PCI huge-mode addressing
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* allows us to circumvent this restriction by splitting PCI space into
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* two 2GB chunks and mapping only one at a time into processor memory.
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* We use MMU protection domains to trap any attempt to access the bank
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* that is not currently mapped. (This isn't fully implemented yet.)
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/io.h>
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#include <linux/sizes.h>
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#include <asm/cp15.h>
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#include <asm/cputype.h>
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#include <asm/cacheflush.h>
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#include <asm/early_ioremap.h>
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#include <asm/mmu_context.h>
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#include <asm/pgalloc.h>
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#include <asm/tlbflush.h>
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#include <asm/system_info.h>
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#include <asm/mach/map.h>
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#include <asm/mach/pci.h>
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#include "mm.h"
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LIST_HEAD(static_vmlist);
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static struct static_vm *find_static_vm_paddr(phys_addr_t paddr,
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size_t size, unsigned int mtype)
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{
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struct static_vm *svm;
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struct vm_struct *vm;
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list_for_each_entry(svm, &static_vmlist, list) {
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vm = &svm->vm;
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if (!(vm->flags & VM_ARM_STATIC_MAPPING))
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continue;
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if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
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continue;
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if (vm->phys_addr > paddr ||
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paddr + size - 1 > vm->phys_addr + vm->size - 1)
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continue;
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return svm;
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}
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return NULL;
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}
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struct static_vm *find_static_vm_vaddr(void *vaddr)
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{
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struct static_vm *svm;
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struct vm_struct *vm;
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list_for_each_entry(svm, &static_vmlist, list) {
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vm = &svm->vm;
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/* static_vmlist is ascending order */
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if (vm->addr > vaddr)
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break;
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if (vm->addr <= vaddr && vm->addr + vm->size > vaddr)
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return svm;
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}
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return NULL;
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}
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void __init add_static_vm_early(struct static_vm *svm)
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{
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struct static_vm *curr_svm;
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struct vm_struct *vm;
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void *vaddr;
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vm = &svm->vm;
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vm_area_add_early(vm);
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vaddr = vm->addr;
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list_for_each_entry(curr_svm, &static_vmlist, list) {
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vm = &curr_svm->vm;
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if (vm->addr > vaddr)
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break;
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}
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list_add_tail(&svm->list, &curr_svm->list);
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}
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int ioremap_page(unsigned long virt, unsigned long phys,
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const struct mem_type *mtype)
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{
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return ioremap_page_range(virt, virt + PAGE_SIZE, phys,
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__pgprot(mtype->prot_pte));
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}
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EXPORT_SYMBOL(ioremap_page);
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void __check_vmalloc_seq(struct mm_struct *mm)
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{
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unsigned int seq;
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do {
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seq = init_mm.context.vmalloc_seq;
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memcpy(pgd_offset(mm, VMALLOC_START),
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pgd_offset_k(VMALLOC_START),
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sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
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pgd_index(VMALLOC_START)));
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mm->context.vmalloc_seq = seq;
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} while (seq != init_mm.context.vmalloc_seq);
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}
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#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
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/*
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* Section support is unsafe on SMP - If you iounmap and ioremap a region,
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* the other CPUs will not see this change until their next context switch.
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* Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
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* which requires the new ioremap'd region to be referenced, the CPU will
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* reference the _old_ region.
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*
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* Note that get_vm_area_caller() allocates a guard 4K page, so we need to
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* mask the size back to 1MB aligned or we will overflow in the loop below.
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*/
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static void unmap_area_sections(unsigned long virt, unsigned long size)
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{
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unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1));
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmdp;
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flush_cache_vunmap(addr, end);
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pgd = pgd_offset_k(addr);
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pud = pud_offset(pgd, addr);
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pmdp = pmd_offset(pud, addr);
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do {
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pmd_t pmd = *pmdp;
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if (!pmd_none(pmd)) {
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/*
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* Clear the PMD from the page table, and
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* increment the vmalloc sequence so others
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* notice this change.
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*
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* Note: this is still racy on SMP machines.
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*/
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pmd_clear(pmdp);
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init_mm.context.vmalloc_seq++;
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/*
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* Free the page table, if there was one.
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*/
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if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
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pte_free_kernel(&init_mm, pmd_page_vaddr(pmd));
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}
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addr += PMD_SIZE;
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pmdp += 2;
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} while (addr < end);
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/*
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* Ensure that the active_mm is up to date - we want to
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* catch any use-after-iounmap cases.
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*/
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if (current->active_mm->context.vmalloc_seq != init_mm.context.vmalloc_seq)
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__check_vmalloc_seq(current->active_mm);
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flush_tlb_kernel_range(virt, end);
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}
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static int
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remap_area_sections(unsigned long virt, unsigned long pfn,
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size_t size, const struct mem_type *type)
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{
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unsigned long addr = virt, end = virt + size;
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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/*
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* Remove and free any PTE-based mapping, and
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* sync the current kernel mapping.
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*/
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unmap_area_sections(virt, size);
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pgd = pgd_offset_k(addr);
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pud = pud_offset(pgd, addr);
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pmd = pmd_offset(pud, addr);
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do {
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pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
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pfn += SZ_1M >> PAGE_SHIFT;
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pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
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pfn += SZ_1M >> PAGE_SHIFT;
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flush_pmd_entry(pmd);
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addr += PMD_SIZE;
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pmd += 2;
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} while (addr < end);
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return 0;
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}
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static int
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remap_area_supersections(unsigned long virt, unsigned long pfn,
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size_t size, const struct mem_type *type)
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{
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unsigned long addr = virt, end = virt + size;
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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/*
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* Remove and free any PTE-based mapping, and
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* sync the current kernel mapping.
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*/
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unmap_area_sections(virt, size);
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pgd = pgd_offset_k(virt);
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pud = pud_offset(pgd, addr);
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pmd = pmd_offset(pud, addr);
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do {
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unsigned long super_pmd_val, i;
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super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect |
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PMD_SECT_SUPER;
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super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
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for (i = 0; i < 8; i++) {
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pmd[0] = __pmd(super_pmd_val);
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pmd[1] = __pmd(super_pmd_val);
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flush_pmd_entry(pmd);
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addr += PMD_SIZE;
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pmd += 2;
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}
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pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
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} while (addr < end);
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return 0;
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}
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#endif
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static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
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unsigned long offset, size_t size, unsigned int mtype, void *caller)
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{
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const struct mem_type *type;
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int err;
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unsigned long addr;
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struct vm_struct *area;
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phys_addr_t paddr = __pfn_to_phys(pfn);
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#ifndef CONFIG_ARM_LPAE
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/*
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* High mappings must be supersection aligned
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*/
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if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK))
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return NULL;
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#endif
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type = get_mem_type(mtype);
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if (!type)
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return NULL;
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/*
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* Page align the mapping size, taking account of any offset.
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*/
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size = PAGE_ALIGN(offset + size);
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/*
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* Try to reuse one of the static mapping whenever possible.
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*/
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if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) {
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struct static_vm *svm;
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svm = find_static_vm_paddr(paddr, size, mtype);
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if (svm) {
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addr = (unsigned long)svm->vm.addr;
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addr += paddr - svm->vm.phys_addr;
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return (void __iomem *) (offset + addr);
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}
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}
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/*
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* Don't allow RAM to be mapped with mismatched attributes - this
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* causes problems with ARMv6+
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*/
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if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW))
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return NULL;
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area = get_vm_area_caller(size, VM_IOREMAP, caller);
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if (!area)
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return NULL;
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addr = (unsigned long)area->addr;
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area->phys_addr = paddr;
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#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
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if (DOMAIN_IO == 0 &&
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(((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
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cpu_is_xsc3()) && pfn >= 0x100000 &&
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!((paddr | size | addr) & ~SUPERSECTION_MASK)) {
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area->flags |= VM_ARM_SECTION_MAPPING;
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err = remap_area_supersections(addr, pfn, size, type);
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} else if (!((paddr | size | addr) & ~PMD_MASK)) {
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area->flags |= VM_ARM_SECTION_MAPPING;
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err = remap_area_sections(addr, pfn, size, type);
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} else
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#endif
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err = ioremap_page_range(addr, addr + size, paddr,
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__pgprot(type->prot_pte));
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if (err) {
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vunmap((void *)addr);
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return NULL;
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}
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flush_cache_vmap(addr, addr + size);
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return (void __iomem *) (offset + addr);
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}
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void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size,
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unsigned int mtype, void *caller)
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{
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phys_addr_t last_addr;
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unsigned long offset = phys_addr & ~PAGE_MASK;
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unsigned long pfn = __phys_to_pfn(phys_addr);
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/*
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* Don't allow wraparound or zero size
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*/
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last_addr = phys_addr + size - 1;
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if (!size || last_addr < phys_addr)
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return NULL;
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return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
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caller);
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}
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/*
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* Remap an arbitrary physical address space into the kernel virtual
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* address space. Needed when the kernel wants to access high addresses
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* directly.
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*
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* NOTE! We need to allow non-page-aligned mappings too: we will obviously
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* have to convert them into an offset in a page-aligned mapping, but the
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* caller shouldn't need to know that small detail.
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*/
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void __iomem *
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__arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
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unsigned int mtype)
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{
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return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
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__builtin_return_address(0));
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}
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EXPORT_SYMBOL(__arm_ioremap_pfn);
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void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,
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unsigned int, void *) =
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__arm_ioremap_caller;
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void __iomem *ioremap(resource_size_t res_cookie, size_t size)
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{
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return arch_ioremap_caller(res_cookie, size, MT_DEVICE,
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__builtin_return_address(0));
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}
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EXPORT_SYMBOL(ioremap);
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void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size)
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__alias(ioremap_cached);
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void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size)
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{
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return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED,
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__builtin_return_address(0));
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}
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EXPORT_SYMBOL(ioremap_cache);
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EXPORT_SYMBOL(ioremap_cached);
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void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size)
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{
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return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC,
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__builtin_return_address(0));
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}
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EXPORT_SYMBOL(ioremap_wc);
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/*
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* Remap an arbitrary physical address space into the kernel virtual
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* address space as memory. Needed when the kernel wants to execute
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* code in external memory. This is needed for reprogramming source
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* clocks that would affect normal memory for example. Please see
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* CONFIG_GENERIC_ALLOCATOR for allocating external memory.
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*/
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void __iomem *
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__arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached)
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{
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unsigned int mtype;
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if (cached)
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mtype = MT_MEMORY_RWX;
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else
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mtype = MT_MEMORY_RWX_NONCACHED;
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return __arm_ioremap_caller(phys_addr, size, mtype,
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__builtin_return_address(0));
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}
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void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
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{
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return (__force void *)arch_ioremap_caller(phys_addr, size,
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MT_MEMORY_RW,
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__builtin_return_address(0));
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}
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void __iounmap(volatile void __iomem *io_addr)
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{
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void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
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struct static_vm *svm;
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/* If this is a static mapping, we must leave it alone */
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svm = find_static_vm_vaddr(addr);
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if (svm)
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return;
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#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
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{
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struct vm_struct *vm;
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vm = find_vm_area(addr);
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/*
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* If this is a section based mapping we need to handle it
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* specially as the VM subsystem does not know how to handle
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* such a beast.
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*/
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if (vm && (vm->flags & VM_ARM_SECTION_MAPPING))
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unmap_area_sections((unsigned long)vm->addr, vm->size);
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}
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#endif
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vunmap(addr);
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}
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void (*arch_iounmap)(volatile void __iomem *) = __iounmap;
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void iounmap(volatile void __iomem *cookie)
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{
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arch_iounmap(cookie);
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}
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EXPORT_SYMBOL(iounmap);
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#ifdef CONFIG_PCI
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static int pci_ioremap_mem_type = MT_DEVICE;
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void pci_ioremap_set_mem_type(int mem_type)
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{
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pci_ioremap_mem_type = mem_type;
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}
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int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
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{
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BUG_ON(offset + SZ_64K > IO_SPACE_LIMIT);
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return ioremap_page_range(PCI_IO_VIRT_BASE + offset,
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PCI_IO_VIRT_BASE + offset + SZ_64K,
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phys_addr,
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__pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte));
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}
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EXPORT_SYMBOL_GPL(pci_ioremap_io);
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#endif
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/*
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* Must be called after early_fixmap_init
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*/
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void __init early_ioremap_init(void)
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{
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early_ioremap_setup();
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}
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