1 /* 2 * This file contains ioremap and related functions for 64-bit machines. 3 * 4 * Derived from arch/ppc64/mm/init.c 5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 6 * 7 * Modifications by Paul Mackerras (PowerMac) (paulus@samba.org) 8 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 9 * Copyright (C) 1996 Paul Mackerras 10 * 11 * Derived from "arch/i386/mm/init.c" 12 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 13 * 14 * Dave Engebretsen <engebret@us.ibm.com> 15 * Rework for PPC64 port. 16 * 17 * This program is free software; you can redistribute it and/or 18 * modify it under the terms of the GNU General Public License 19 * as published by the Free Software Foundation; either version 20 * 2 of the License, or (at your option) any later version. 21 * 22 */ 23 24 #include <linux/signal.h> 25 #include <linux/sched.h> 26 #include <linux/kernel.h> 27 #include <linux/errno.h> 28 #include <linux/string.h> 29 #include <linux/types.h> 30 #include <linux/mman.h> 31 #include <linux/mm.h> 32 #include <linux/swap.h> 33 #include <linux/stddef.h> 34 #include <linux/vmalloc.h> 35 #include <linux/init.h> 36 37 #include <asm/pgalloc.h> 38 #include <asm/page.h> 39 #include <asm/prom.h> 40 #include <asm/io.h> 41 #include <asm/mmu_context.h> 42 #include <asm/pgtable.h> 43 #include <asm/mmu.h> 44 #include <asm/smp.h> 45 #include <asm/machdep.h> 46 #include <asm/tlb.h> 47 #include <asm/processor.h> 48 #include <asm/cputable.h> 49 #include <asm/sections.h> 50 #include <asm/system.h> 51 #include <asm/abs_addr.h> 52 #include <asm/firmware.h> 53 54 #include "mmu_decl.h" 55 56 unsigned long ioremap_bot = IOREMAP_BASE; 57 58 /* 59 * map_io_page currently only called by __ioremap 60 * map_io_page adds an entry to the ioremap page table 61 * and adds an entry to the HPT, possibly bolting it 62 */ 63 static int map_io_page(unsigned long ea, unsigned long pa, int flags) 64 { 65 pgd_t *pgdp; 66 pud_t *pudp; 67 pmd_t *pmdp; 68 pte_t *ptep; 69 70 if (mem_init_done) { 71 pgdp = pgd_offset_k(ea); 72 pudp = pud_alloc(&init_mm, pgdp, ea); 73 if (!pudp) 74 return -ENOMEM; 75 pmdp = pmd_alloc(&init_mm, pudp, ea); 76 if (!pmdp) 77 return -ENOMEM; 78 ptep = pte_alloc_kernel(pmdp, ea); 79 if (!ptep) 80 return -ENOMEM; 81 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, 82 __pgprot(flags))); 83 } else { 84 /* 85 * If the mm subsystem is not fully up, we cannot create a 86 * linux page table entry for this mapping. Simply bolt an 87 * entry in the hardware page table. 88 * 89 */ 90 if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags, 91 mmu_io_psize, mmu_kernel_ssize)) { 92 printk(KERN_ERR "Failed to do bolted mapping IO " 93 "memory at %016lx !\n", pa); 94 return -ENOMEM; 95 } 96 } 97 return 0; 98 } 99 100 101 /** 102 * __ioremap_at - Low level function to establish the page tables 103 * for an IO mapping 104 */ 105 void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size, 106 unsigned long flags) 107 { 108 unsigned long i; 109 110 if ((flags & _PAGE_PRESENT) == 0) 111 flags |= pgprot_val(PAGE_KERNEL); 112 113 WARN_ON(pa & ~PAGE_MASK); 114 WARN_ON(((unsigned long)ea) & ~PAGE_MASK); 115 WARN_ON(size & ~PAGE_MASK); 116 117 for (i = 0; i < size; i += PAGE_SIZE) 118 if (map_io_page((unsigned long)ea+i, pa+i, flags)) 119 return NULL; 120 121 return (void __iomem *)ea; 122 } 123 124 /** 125 * __iounmap_from - Low level function to tear down the page tables 126 * for an IO mapping. This is used for mappings that 127 * are manipulated manually, like partial unmapping of 128 * PCI IOs or ISA space. 129 */ 130 void __iounmap_at(void *ea, unsigned long size) 131 { 132 WARN_ON(((unsigned long)ea) & ~PAGE_MASK); 133 WARN_ON(size & ~PAGE_MASK); 134 135 unmap_kernel_range((unsigned long)ea, size); 136 } 137 138 void __iomem * __ioremap(phys_addr_t addr, unsigned long size, 139 unsigned long flags) 140 { 141 phys_addr_t paligned; 142 void __iomem *ret; 143 144 /* 145 * Choose an address to map it to. 146 * Once the imalloc system is running, we use it. 147 * Before that, we map using addresses going 148 * up from ioremap_bot. imalloc will use 149 * the addresses from ioremap_bot through 150 * IMALLOC_END 151 * 152 */ 153 paligned = addr & PAGE_MASK; 154 size = PAGE_ALIGN(addr + size) - paligned; 155 156 if ((size == 0) || (paligned == 0)) 157 return NULL; 158 159 if (mem_init_done) { 160 struct vm_struct *area; 161 162 area = __get_vm_area(size, VM_IOREMAP, 163 ioremap_bot, IOREMAP_END); 164 if (area == NULL) 165 return NULL; 166 ret = __ioremap_at(paligned, area->addr, size, flags); 167 if (!ret) 168 vunmap(area->addr); 169 } else { 170 ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags); 171 if (ret) 172 ioremap_bot += size; 173 } 174 175 if (ret) 176 ret += addr & ~PAGE_MASK; 177 return ret; 178 } 179 180 181 void __iomem * ioremap(phys_addr_t addr, unsigned long size) 182 { 183 unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED; 184 185 if (ppc_md.ioremap) 186 return ppc_md.ioremap(addr, size, flags); 187 return __ioremap(addr, size, flags); 188 } 189 190 void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size, 191 unsigned long flags) 192 { 193 if (ppc_md.ioremap) 194 return ppc_md.ioremap(addr, size, flags); 195 return __ioremap(addr, size, flags); 196 } 197 198 199 /* 200 * Unmap an IO region and remove it from imalloc'd list. 201 * Access to IO memory should be serialized by driver. 202 */ 203 void __iounmap(volatile void __iomem *token) 204 { 205 void *addr; 206 207 if (!mem_init_done) 208 return; 209 210 addr = (void *) ((unsigned long __force) 211 PCI_FIX_ADDR(token) & PAGE_MASK); 212 if ((unsigned long)addr < ioremap_bot) { 213 printk(KERN_WARNING "Attempt to iounmap early bolted mapping" 214 " at 0x%p\n", addr); 215 return; 216 } 217 vunmap(addr); 218 } 219 220 void iounmap(volatile void __iomem *token) 221 { 222 if (ppc_md.iounmap) 223 ppc_md.iounmap(token); 224 else 225 __iounmap(token); 226 } 227 228 EXPORT_SYMBOL(ioremap); 229 EXPORT_SYMBOL(ioremap_flags); 230 EXPORT_SYMBOL(__ioremap); 231 EXPORT_SYMBOL(__ioremap_at); 232 EXPORT_SYMBOL(iounmap); 233 EXPORT_SYMBOL(__iounmap); 234 EXPORT_SYMBOL(__iounmap_at); 235