2 * This file contains ioremap and related functions for 64-bit machines.
4 * Derived from arch/ppc64/mm/init.c
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
12 * Derived from "arch/i386/mm/init.c"
13 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
15 * Dave Engebretsen <engebret@us.ibm.com>
16 * Rework for PPC64 port.
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
25 #include <linux/signal.h>
26 #include <linux/sched.h>
27 #include <linux/kernel.h>
28 #include <linux/errno.h>
29 #include <linux/string.h>
30 #include <linux/types.h>
31 #include <linux/mman.h>
33 #include <linux/swap.h>
34 #include <linux/stddef.h>
35 #include <linux/vmalloc.h>
36 #include <linux/init.h>
38 #include <asm/pgalloc.h>
42 #include <asm/mmu_context.h>
43 #include <asm/pgtable.h>
46 #include <asm/machdep.h>
48 #include <asm/processor.h>
49 #include <asm/cputable.h>
50 #include <asm/sections.h>
51 #include <asm/system.h>
52 #include <asm/abs_addr.h>
53 #include <asm/firmware.h>
57 unsigned long ioremap_bot = IOREMAP_BASE;
60 * map_io_page currently only called by __ioremap
61 * map_io_page adds an entry to the ioremap page table
62 * and adds an entry to the HPT, possibly bolting it
64 static int map_io_page(unsigned long ea, unsigned long pa, int flags)
72 pgdp = pgd_offset_k(ea);
73 pudp = pud_alloc(&init_mm, pgdp, ea);
76 pmdp = pmd_alloc(&init_mm, pudp, ea);
79 ptep = pte_alloc_kernel(pmdp, ea);
82 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
86 * If the mm subsystem is not fully up, we cannot create a
87 * linux page table entry for this mapping. Simply bolt an
88 * entry in the hardware page table.
91 if (htab_bolt_mapping(ea, (unsigned long)ea + PAGE_SIZE,
92 pa, flags, mmu_io_psize)) {
93 printk(KERN_ERR "Failed to do bolted mapping IO "
94 "memory at %016lx !\n", pa);
103 * __ioremap_at - Low level function to establish the page tables
106 void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
111 if ((flags & _PAGE_PRESENT) == 0)
112 flags |= pgprot_val(PAGE_KERNEL);
114 WARN_ON(pa & ~PAGE_MASK);
115 WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
116 WARN_ON(size & ~PAGE_MASK);
118 for (i = 0; i < size; i += PAGE_SIZE)
119 if (map_io_page((unsigned long)ea+i, pa+i, flags))
122 return (void __iomem *)ea;
126 * __iounmap_from - Low level function to tear down the page tables
127 * for an IO mapping. This is used for mappings that
128 * are manipulated manually, like partial unmapping of
129 * PCI IOs or ISA space.
131 void __iounmap_at(void *ea, unsigned long size)
133 WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
134 WARN_ON(size & ~PAGE_MASK);
136 unmap_kernel_range((unsigned long)ea, size);
139 void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
142 phys_addr_t paligned;
146 * Choose an address to map it to.
147 * Once the imalloc system is running, we use it.
148 * Before that, we map using addresses going
149 * up from ioremap_bot. imalloc will use
150 * the addresses from ioremap_bot through
154 paligned = addr & PAGE_MASK;
155 size = PAGE_ALIGN(addr + size) - paligned;
157 if ((size == 0) || (paligned == 0))
161 struct vm_struct *area;
163 area = __get_vm_area(size, VM_IOREMAP,
164 ioremap_bot, IOREMAP_END);
167 ret = __ioremap_at(paligned, area->addr, size, flags);
171 ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
177 ret += addr & ~PAGE_MASK;
182 void __iomem * ioremap(phys_addr_t addr, unsigned long size)
184 unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
187 return ppc_md.ioremap(addr, size, flags);
188 return __ioremap(addr, size, flags);
191 void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size,
195 return ppc_md.ioremap(addr, size, flags);
196 return __ioremap(addr, size, flags);
201 * Unmap an IO region and remove it from imalloc'd list.
202 * Access to IO memory should be serialized by driver.
204 void __iounmap(volatile void __iomem *token)
211 addr = (void *) ((unsigned long __force)
212 PCI_FIX_ADDR(token) & PAGE_MASK);
213 if ((unsigned long)addr < ioremap_bot) {
214 printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
221 void iounmap(volatile void __iomem *token)
224 ppc_md.iounmap(token);
229 EXPORT_SYMBOL(ioremap);
230 EXPORT_SYMBOL(ioremap_flags);
231 EXPORT_SYMBOL(__ioremap);
232 EXPORT_SYMBOL(iounmap);
233 EXPORT_SYMBOL(__iounmap);