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 static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss; 107 #if CONFIG_ARM64_PGTABLE_LEVELS > 2 108 static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss; 109 #endif 110 #if CONFIG_ARM64_PGTABLE_LEVELS > 3 111 static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss; 112 #endif 113 114 static inline pud_t * __init early_ioremap_pud(unsigned long addr) 115 { 116 pgd_t *pgd; 117 118 pgd = pgd_offset_k(addr); 119 BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd)); 120 121 return pud_offset(pgd, addr); 122 } 123 124 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) 125 { 126 pud_t *pud = early_ioremap_pud(addr); 127 128 BUG_ON(pud_none(*pud) || pud_bad(*pud)); 129 130 return pmd_offset(pud, addr); 131 } 132 133 static inline pte_t * __init early_ioremap_pte(unsigned long addr) 134 { 135 pmd_t *pmd = early_ioremap_pmd(addr); 136 137 BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd)); 138 139 return pte_offset_kernel(pmd, addr); 140 } 141 142 void __init early_ioremap_init(void) 143 { 144 pgd_t *pgd; 145 pud_t *pud; 146 pmd_t *pmd; 147 unsigned long addr = fix_to_virt(FIX_BTMAP_BEGIN); 148 149 pgd = pgd_offset_k(addr); 150 pgd_populate(&init_mm, pgd, bm_pud); 151 pud = pud_offset(pgd, addr); 152 pud_populate(&init_mm, pud, bm_pmd); 153 pmd = pmd_offset(pud, addr); 154 pmd_populate_kernel(&init_mm, pmd, bm_pte); 155 156 /* 157 * The boot-ioremap range spans multiple pmds, for which 158 * we are not prepared: 159 */ 160 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) 161 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); 162 163 if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) { 164 WARN_ON(1); 165 pr_warn("pmd %p != %p\n", 166 pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))); 167 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", 168 fix_to_virt(FIX_BTMAP_BEGIN)); 169 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", 170 fix_to_virt(FIX_BTMAP_END)); 171 172 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); 173 pr_warn("FIX_BTMAP_BEGIN: %d\n", 174 FIX_BTMAP_BEGIN); 175 } 176 177 early_ioremap_setup(); 178 } 179 180 void __init __early_set_fixmap(enum fixed_addresses idx, 181 phys_addr_t phys, pgprot_t flags) 182 { 183 unsigned long addr = __fix_to_virt(idx); 184 pte_t *pte; 185 186 if (idx >= __end_of_fixed_addresses) { 187 BUG(); 188 return; 189 } 190 191 pte = early_ioremap_pte(addr); 192 193 if (pgprot_val(flags)) 194 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); 195 else { 196 pte_clear(&init_mm, addr, pte); 197 flush_tlb_kernel_range(addr, addr+PAGE_SIZE); 198 } 199 } 200