2 * This file contains the routines setting up the linux page tables.
5 * Derived from arch/ppc/mm/init.c:
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
8 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
9 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
10 * Copyright (C) 1996 Paul Mackerras
11 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
13 * Derived from "arch/i386/mm/init.c"
14 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/types.h>
27 #include <linux/vmalloc.h>
28 #include <linux/init.h>
29 #include <linux/highmem.h>
31 #include <asm/pgtable.h>
32 #include <asm/pgalloc.h>
37 unsigned long ioremap_base;
38 unsigned long ioremap_bot;
41 #if defined(CONFIG_6xx)
45 extern char etext[], _stext[];
48 extern void hash_page_sync(void);
52 extern unsigned long v_mapped_by_bats(unsigned long va);
53 extern unsigned long p_mapped_by_bats(unsigned long pa);
54 void setbat(int index, unsigned long virt, unsigned long phys,
55 unsigned int size, int flags);
57 #else /* !HAVE_BATS */
58 #define v_mapped_by_bats(x) (0UL)
59 #define p_mapped_by_bats(x) (0UL)
60 #endif /* HAVE_BATS */
62 #ifdef CONFIG_PTE_64BIT
63 /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
69 pgd_t *pgd_alloc(struct mm_struct *mm)
73 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
77 void pgd_free(pgd_t *pgd)
79 free_pages((unsigned long)pgd, PGDIR_ORDER);
82 __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
85 extern int mem_init_done;
86 extern void *early_get_page(void);
89 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
91 pte = (pte_t *)early_get_page();
98 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
100 struct page *ptepage;
102 #ifdef CONFIG_HIGHPTE
103 gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
105 gfp_t flags = GFP_KERNEL | __GFP_REPEAT;
108 ptepage = alloc_pages(flags, 0);
110 clear_highpage(ptepage);
114 void pte_free_kernel(pte_t *pte)
119 free_page((unsigned long)pte);
122 void pte_free(struct page *ptepage)
127 __free_page(ptepage);
130 #ifndef CONFIG_PHYS_64BIT
132 ioremap(phys_addr_t addr, unsigned long size)
134 return __ioremap(addr, size, _PAGE_NO_CACHE);
136 #else /* CONFIG_PHYS_64BIT */
138 ioremap64(unsigned long long addr, unsigned long size)
140 return __ioremap(addr, size, _PAGE_NO_CACHE);
144 ioremap(phys_addr_t addr, unsigned long size)
146 phys_addr_t addr64 = fixup_bigphys_addr(addr, size);
148 return ioremap64(addr64, size);
150 #endif /* CONFIG_PHYS_64BIT */
153 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
160 * Choose an address to map it to.
161 * Once the vmalloc system is running, we use it.
162 * Before then, we use space going down from ioremap_base
163 * (ioremap_bot records where we're up to).
165 p = addr & PAGE_MASK;
166 size = PAGE_ALIGN(addr + size) - p;
169 * If the address lies within the first 16 MB, assume it's in ISA
172 if (p < 16*1024*1024)
176 * Don't allow anybody to remap normal RAM that we're using.
177 * mem_init() sets high_memory so only do the check after that.
179 if ( mem_init_done && (p < virt_to_phys(high_memory)) )
181 printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p,
182 __builtin_return_address(0));
190 * Is it already mapped? Perhaps overlapped by a previous
191 * BAT mapping. If the whole area is mapped then we're done,
192 * otherwise remap it since we want to keep the virt addrs for
193 * each request contiguous.
195 * We make the assumption here that if the bottom and top
196 * of the range we want are mapped then it's mapped to the
197 * same virt address (and this is contiguous).
200 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
204 struct vm_struct *area;
205 area = get_vm_area(size, VM_IOREMAP);
208 v = (unsigned long) area->addr;
210 v = (ioremap_bot -= size);
213 if ((flags & _PAGE_PRESENT) == 0)
214 flags |= _PAGE_KERNEL;
215 if (flags & _PAGE_NO_CACHE)
216 flags |= _PAGE_GUARDED;
219 * Should check if it is a candidate for a BAT mapping
223 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
224 err = map_page(v+i, p+i, flags);
232 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
235 void iounmap(volatile void __iomem *addr)
238 * If mapped by BATs then there is nothing to do.
239 * Calling vfree() generates a benign warning.
241 if (v_mapped_by_bats((unsigned long)addr)) return;
243 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
244 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
247 void __iomem *ioport_map(unsigned long port, unsigned int len)
249 return (void __iomem *) (port + _IO_BASE);
252 void ioport_unmap(void __iomem *addr)
256 EXPORT_SYMBOL(ioport_map);
257 EXPORT_SYMBOL(ioport_unmap);
260 map_page(unsigned long va, phys_addr_t pa, int flags)
266 /* Use upper 10 bits of VA to index the first level map */
267 pd = pmd_offset(pgd_offset_k(va), va);
268 /* Use middle 10 bits of VA to index the second-level map */
269 pg = pte_alloc_kernel(pd, va);
272 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
274 flush_HPTE(0, va, pmd_val(*pd));
280 * Map in all of physical memory starting at KERNELBASE.
282 void __init mapin_ram(void)
284 unsigned long v, p, s, f;
288 p = PPC_MEMSTART + s;
289 for (; s < total_lowmem; s += PAGE_SIZE) {
290 if ((char *) v >= _stext && (char *) v < etext)
300 /* is x a power of 4? */
301 #define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1)
304 * Set up a mapping for a block of I/O.
305 * virt, phys, size must all be page-aligned.
306 * This should only be called before ioremap is called.
308 void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
309 unsigned int size, int flags)
313 if (virt > KERNELBASE && virt < ioremap_bot)
314 ioremap_bot = ioremap_base = virt;
318 * Use a BAT for this if possible...
320 if (io_bat_index < 2 && is_power_of_2(size)
321 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
322 setbat(io_bat_index, virt, phys, size, flags);
326 #endif /* HAVE_BATS */
328 /* No BATs available, put it in the page tables. */
329 for (i = 0; i < size; i += PAGE_SIZE)
330 map_page(virt + i, phys + i, flags);
333 /* Scan the real Linux page tables and return a PTE pointer for
334 * a virtual address in a context.
335 * Returns true (1) if PTE was found, zero otherwise. The pointer to
336 * the PTE pointer is unmodified if PTE is not found.
339 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
346 pgd = pgd_offset(mm, addr & PAGE_MASK);
348 pmd = pmd_offset(pgd, addr & PAGE_MASK);
349 if (pmd_present(*pmd)) {
350 pte = pte_offset_map(pmd, addr & PAGE_MASK);
356 /* XXX caller needs to do pte_unmap, yuck */
363 /* Find physical address for this virtual address. Normally used by
364 * I/O functions, but anyone can call it.
366 unsigned long iopa(unsigned long addr)
370 /* I don't know why this won't work on PMacs or CHRP. It
371 * appears there is some bug, or there is some implicit
372 * mapping done not properly represented by BATs or in page
373 * tables.......I am actively working on resolving this, but
374 * can't hold up other stuff. -- Dan
377 struct mm_struct *mm;
380 pa = v_mapped_by_bats(addr);
384 /* Allow mapping of user addresses (within the thread)
385 * for DMA if necessary.
387 if (addr < TASK_SIZE)
393 if (get_pteptr(mm, addr, &pte, NULL)) {
394 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);