1 /* 2 * Based on arch/arm/mm/ioremap.c 3 * 4 * (C) Copyright 1995 1996 Linus Torvalds 5 * Hacked for ARM by Phil Blundell <philb@gnu.org> 6 * Hacked to allow all architectures to build, and various cleanups 7 * by Russell King 8 * Copyright (C) 2012 ARM Ltd. 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program. If not, see <http://www.gnu.org/licenses/>. 21 */ 22 23 #include <linux/export.h> 24 #include <linux/mm.h> 25 #include <linux/vmalloc.h> 26 #include <linux/io.h> 27 28 #include <asm/fixmap.h> 29 #include <asm/tlbflush.h> 30 #include <asm/pgalloc.h> 31 32 static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, 33 pgprot_t prot, void *caller) 34 { 35 unsigned long last_addr; 36 unsigned long offset = phys_addr & ~PAGE_MASK; 37 int err; 38 unsigned long addr; 39 struct vm_struct *area; 40 41 /* 42 * Page align the mapping address and size, taking account of any 43 * offset. 44 */ 45 phys_addr &= PAGE_MASK; 46 size = PAGE_ALIGN(size + offset); 47 48 /* 49 * Don't allow wraparound, zero size or outside PHYS_MASK. 50 */ 51 last_addr = phys_addr + size - 1; 52 if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK)) 53 return NULL; 54 55 /* 56 * Don't allow RAM to be mapped. 57 */ 58 if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) 59 return NULL; 60 61 area = get_vm_area_caller(size, VM_IOREMAP, caller); 62 if (!area) 63 return NULL; 64 addr = (unsigned long)area->addr; 65 66 err = ioremap_page_range(addr, addr + size, phys_addr, prot); 67 if (err) { 68 vunmap((void *)addr); 69 return NULL; 70 } 71 72 return (void __iomem *)(offset + addr); 73 } 74 75 void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot) 76 { 77 return __ioremap_caller(phys_addr, size, prot, 78 __builtin_return_address(0)); 79 } 80 EXPORT_SYMBOL(__ioremap); 81 82 void __iounmap(volatile void __iomem *io_addr) 83 { 84 unsigned long addr = (unsigned long)io_addr & PAGE_MASK; 85 86 /* 87 * We could get an address outside vmalloc range in case 88 * of ioremap_cache() reusing a RAM mapping. 89 */ 90 if (VMALLOC_START <= addr && addr < VMALLOC_END) 91 vunmap((void *)addr); 92 } 93 EXPORT_SYMBOL(__iounmap); 94 95 void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) 96 { 97 /* For normal memory we already have a cacheable mapping. */ 98 if (pfn_valid(__phys_to_pfn(phys_addr))) 99 return (void __iomem *)__phys_to_virt(phys_addr); 100 101 return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), 102 __builtin_return_address(0)); 103 } 104 EXPORT_SYMBOL(ioremap_cache); 105 106 #ifndef CONFIG_ARM64_64K_PAGES 107 static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss; 108 #endif 109 110 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) 111 { 112 pgd_t *pgd; 113 pud_t *pud; 114 115 pgd = pgd_offset_k(addr); 116 BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd)); 117 118 pud = pud_offset(pgd, addr); 119 BUG_ON(pud_none(*pud) || pud_bad(*pud)); 120 121 return pmd_offset(pud, addr); 122 } 123 124 static inline pte_t * __init early_ioremap_pte(unsigned long addr) 125 { 126 pmd_t *pmd = early_ioremap_pmd(addr); 127 128 BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd)); 129 130 return pte_offset_kernel(pmd, addr); 131 } 132 133 void __init early_ioremap_init(void) 134 { 135 pmd_t *pmd; 136 137 pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); 138 #ifndef CONFIG_ARM64_64K_PAGES 139 /* need to populate pmd for 4k pagesize only */ 140 pmd_populate_kernel(&init_mm, pmd, bm_pte); 141 #endif 142 /* 143 * The boot-ioremap range spans multiple pmds, for which 144 * we are not prepared: 145 */ 146 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) 147 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); 148 149 if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { 150 WARN_ON(1); 151 pr_warn("pmd %p != %p\n", 152 pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); 153 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", 154 fix_to_virt(FIX_BTMAP_BEGIN)); 155 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", 156 fix_to_virt(FIX_BTMAP_END)); 157 158 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); 159 pr_warn("FIX_BTMAP_BEGIN: %d\n", 160 FIX_BTMAP_BEGIN); 161 } 162 163 early_ioremap_setup(); 164 } 165 166 void __init __early_set_fixmap(enum fixed_addresses idx, 167 phys_addr_t phys, pgprot_t flags) 168 { 169 unsigned long addr = __fix_to_virt(idx); 170 pte_t *pte; 171 172 if (idx >= __end_of_fixed_addresses) { 173 BUG(); 174 return; 175 } 176 177 pte = early_ioremap_pte(addr); 178 179 if (pgprot_val(flags)) 180 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); 181 else { 182 pte_clear(&init_mm, addr, pte); 183 flush_tlb_kernel_range(addr, addr+PAGE_SIZE); 184 } 185 } 186