diff options
Diffstat (limited to 'arch/arm64/mm/ioremap.c')
| -rw-r--r-- | arch/arm64/mm/ioremap.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c new file mode 100644 index 00000000000..7ec328392ae --- /dev/null +++ b/arch/arm64/mm/ioremap.c @@ -0,0 +1,185 @@ +/* + * Based on arch/arm/mm/ioremap.c + * + * (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 + * Copyright (C) 2012 ARM Ltd. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> +#include <linux/io.h> + +#include <asm/fixmap.h> +#include <asm/tlbflush.h> +#include <asm/pgalloc.h> + +static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, + pgprot_t prot, void *caller) +{ + unsigned long last_addr; + unsigned long offset = phys_addr & ~PAGE_MASK; + int err; + unsigned long addr; + struct vm_struct *area; + + /* + * Page align the mapping address and size, taking account of any + * offset. + */ + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(size + offset); + + /* + * Don't allow wraparound, zero size or outside PHYS_MASK. + */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK)) + return NULL; + + /* + * Don't allow RAM to be mapped. + */ + if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) + return NULL; + + area = get_vm_area_caller(size, VM_IOREMAP, caller); + if (!area) + return NULL; + addr = (unsigned long)area->addr; + + err = ioremap_page_range(addr, addr + size, phys_addr, prot); + if (err) { + vunmap((void *)addr); + return NULL; + } + + return (void __iomem *)(offset + addr); +} + +void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot) +{ + return __ioremap_caller(phys_addr, size, prot, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(__ioremap); + +void __iounmap(volatile void __iomem *io_addr) +{ + unsigned long addr = (unsigned long)io_addr & PAGE_MASK; + + /* + * We could get an address outside vmalloc range in case + * of ioremap_cache() reusing a RAM mapping. + */ + if (VMALLOC_START <= addr && addr < VMALLOC_END) + vunmap((void *)addr); +} +EXPORT_SYMBOL(__iounmap); + +void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) +{ + /* For normal memory we already have a cacheable mapping. */ + if (pfn_valid(__phys_to_pfn(phys_addr))) + return (void __iomem *)__phys_to_virt(phys_addr); + + return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), + __builtin_return_address(0)); +} +EXPORT_SYMBOL(ioremap_cache); + +#ifndef CONFIG_ARM64_64K_PAGES +static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss; +#endif + +static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) +{ + pgd_t *pgd; + pud_t *pud; + + pgd = pgd_offset_k(addr); + BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd)); + + pud = pud_offset(pgd, addr); + BUG_ON(pud_none(*pud) || pud_bad(*pud)); + + return pmd_offset(pud, addr); +} + +static inline pte_t * __init early_ioremap_pte(unsigned long addr) +{ + pmd_t *pmd = early_ioremap_pmd(addr); + + BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd)); + + return pte_offset_kernel(pmd, addr); +} + +void __init early_ioremap_init(void) +{ + pmd_t *pmd; + + pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); +#ifndef CONFIG_ARM64_64K_PAGES + /* need to populate pmd for 4k pagesize only */ + pmd_populate_kernel(&init_mm, pmd, bm_pte); +#endif + /* + * The boot-ioremap range spans multiple pmds, for which + * we are not prepared: + */ + BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) + != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); + + if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { + WARN_ON(1); + pr_warn("pmd %p != %p\n", + pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); + pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", + fix_to_virt(FIX_BTMAP_BEGIN)); + pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", + fix_to_virt(FIX_BTMAP_END)); + + pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); + pr_warn("FIX_BTMAP_BEGIN: %d\n", + FIX_BTMAP_BEGIN); + } + + early_ioremap_setup(); +} + +void __init __early_set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *pte; + + if (idx >= __end_of_fixed_addresses) { + BUG(); + return; + } + + pte = early_ioremap_pte(addr); + + if (pgprot_val(flags)) + set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); + else { + pte_clear(&init_mm, addr, pte); + flush_tlb_kernel_range(addr, addr+PAGE_SIZE); + } +} |