blob: 0a5cd20275c46cbdb7cb1d33085e9ee5b6b2a336 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file contains the routines setting up the linux page tables.
3 * -- paulus
4 *
5 * Derived from arch/ppc/mm/init.c:
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 *
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).
12 *
13 * Derived from "arch/i386/mm/init.c"
14 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
15 *
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.
20 *
21 */
22
23#include <linux/config.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/types.h>
27#include <linux/mm.h>
28#include <linux/vmalloc.h>
29#include <linux/init.h>
30#include <linux/highmem.h>
31
32#include <asm/pgtable.h>
33#include <asm/pgalloc.h>
34#include <asm/io.h>
35
36#include "mmu_decl.h"
37
38unsigned long ioremap_base;
39unsigned long ioremap_bot;
40int io_bat_index;
41
42#if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
43#define HAVE_BATS 1
44#endif
45
46#if defined(CONFIG_FSL_BOOKE)
47#define HAVE_TLBCAM 1
48#endif
49
50extern char etext[], _stext[];
51
52#ifdef CONFIG_SMP
53extern void hash_page_sync(void);
54#endif
55
56#ifdef HAVE_BATS
57extern unsigned long v_mapped_by_bats(unsigned long va);
58extern unsigned long p_mapped_by_bats(unsigned long pa);
59void setbat(int index, unsigned long virt, unsigned long phys,
60 unsigned int size, int flags);
61
62#else /* !HAVE_BATS */
63#define v_mapped_by_bats(x) (0UL)
64#define p_mapped_by_bats(x) (0UL)
65#endif /* HAVE_BATS */
66
67#ifdef HAVE_TLBCAM
68extern unsigned int tlbcam_index;
69extern unsigned int num_tlbcam_entries;
70extern unsigned long v_mapped_by_tlbcam(unsigned long va);
71extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
72#else /* !HAVE_TLBCAM */
73#define v_mapped_by_tlbcam(x) (0UL)
74#define p_mapped_by_tlbcam(x) (0UL)
75#endif /* HAVE_TLBCAM */
76
77#ifdef CONFIG_44x
78/* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
79#define PGDIR_ORDER 1
80#else
81#define PGDIR_ORDER 0
82#endif
83
84pgd_t *pgd_alloc(struct mm_struct *mm)
85{
86 pgd_t *ret;
87
88 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
89 return ret;
90}
91
92void pgd_free(pgd_t *pgd)
93{
94 free_pages((unsigned long)pgd, PGDIR_ORDER);
95}
96
97pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
98{
99 pte_t *pte;
100 extern int mem_init_done;
101 extern void *early_get_page(void);
102
103 if (mem_init_done) {
104 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
105 } else {
106 pte = (pte_t *)early_get_page();
107 if (pte)
108 clear_page(pte);
109 }
110 return pte;
111}
112
113struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
114{
115 struct page *ptepage;
116
117#ifdef CONFIG_HIGHPTE
118 int flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
119#else
120 int flags = GFP_KERNEL | __GFP_REPEAT;
121#endif
122
123 ptepage = alloc_pages(flags, 0);
124 if (ptepage)
125 clear_highpage(ptepage);
126 return ptepage;
127}
128
129void pte_free_kernel(pte_t *pte)
130{
131#ifdef CONFIG_SMP
132 hash_page_sync();
133#endif
134 free_page((unsigned long)pte);
135}
136
137void pte_free(struct page *ptepage)
138{
139#ifdef CONFIG_SMP
140 hash_page_sync();
141#endif
142 __free_page(ptepage);
143}
144
145#ifndef CONFIG_44x
146void __iomem *
147ioremap(phys_addr_t addr, unsigned long size)
148{
149 return __ioremap(addr, size, _PAGE_NO_CACHE);
150}
151#else /* CONFIG_44x */
152void __iomem *
153ioremap64(unsigned long long addr, unsigned long size)
154{
155 return __ioremap(addr, size, _PAGE_NO_CACHE);
156}
157
158void __iomem *
159ioremap(phys_addr_t addr, unsigned long size)
160{
161 phys_addr_t addr64 = fixup_bigphys_addr(addr, size);
162
163 return ioremap64(addr64, size);
164}
165#endif /* CONFIG_44x */
166
167void __iomem *
168__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
169{
170 unsigned long v, i;
171 phys_addr_t p;
172 int err;
173
174 /*
175 * Choose an address to map it to.
176 * Once the vmalloc system is running, we use it.
177 * Before then, we use space going down from ioremap_base
178 * (ioremap_bot records where we're up to).
179 */
180 p = addr & PAGE_MASK;
181 size = PAGE_ALIGN(addr + size) - p;
182
183 /*
184 * If the address lies within the first 16 MB, assume it's in ISA
185 * memory space
186 */
187 if (p < 16*1024*1024)
188 p += _ISA_MEM_BASE;
189
190 /*
191 * Don't allow anybody to remap normal RAM that we're using.
192 * mem_init() sets high_memory so only do the check after that.
193 */
194 if ( mem_init_done && (p < virt_to_phys(high_memory)) )
195 {
196 printk("__ioremap(): phys addr "PTE_FMT" is RAM lr %p\n", p,
197 __builtin_return_address(0));
198 return NULL;
199 }
200
201 if (size == 0)
202 return NULL;
203
204 /*
205 * Is it already mapped? Perhaps overlapped by a previous
206 * BAT mapping. If the whole area is mapped then we're done,
207 * otherwise remap it since we want to keep the virt addrs for
208 * each request contiguous.
209 *
210 * We make the assumption here that if the bottom and top
211 * of the range we want are mapped then it's mapped to the
212 * same virt address (and this is contiguous).
213 * -- Cort
214 */
215 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
216 goto out;
217
218 if ((v = p_mapped_by_tlbcam(p)))
219 goto out;
220
221 if (mem_init_done) {
222 struct vm_struct *area;
223 area = get_vm_area(size, VM_IOREMAP);
224 if (area == 0)
225 return NULL;
226 v = (unsigned long) area->addr;
227 } else {
228 v = (ioremap_bot -= size);
229 }
230
231 if ((flags & _PAGE_PRESENT) == 0)
232 flags |= _PAGE_KERNEL;
233 if (flags & _PAGE_NO_CACHE)
234 flags |= _PAGE_GUARDED;
235
236 /*
237 * Should check if it is a candidate for a BAT mapping
238 */
239
240 err = 0;
241 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
242 err = map_page(v+i, p+i, flags);
243 if (err) {
244 if (mem_init_done)
245 vunmap((void *)v);
246 return NULL;
247 }
248
249out:
250 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
251}
252
253void iounmap(volatile void __iomem *addr)
254{
255 /*
256 * If mapped by BATs then there is nothing to do.
257 * Calling vfree() generates a benign warning.
258 */
259 if (v_mapped_by_bats((unsigned long)addr)) return;
260
261 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
262 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
263}
264
265void __iomem *ioport_map(unsigned long port, unsigned int len)
266{
267 return (void __iomem *) (port + _IO_BASE);
268}
269
270void ioport_unmap(void __iomem *addr)
271{
272 /* Nothing to do */
273}
274EXPORT_SYMBOL(ioport_map);
275EXPORT_SYMBOL(ioport_unmap);
276
277int
278map_page(unsigned long va, phys_addr_t pa, int flags)
279{
280 pmd_t *pd;
281 pte_t *pg;
282 int err = -ENOMEM;
283
284 spin_lock(&init_mm.page_table_lock);
285 /* Use upper 10 bits of VA to index the first level map */
286 pd = pmd_offset(pgd_offset_k(va), va);
287 /* Use middle 10 bits of VA to index the second-level map */
288 pg = pte_alloc_kernel(&init_mm, pd, va);
289 if (pg != 0) {
290 err = 0;
291 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
292 if (mem_init_done)
293 flush_HPTE(0, va, pmd_val(*pd));
294 }
295 spin_unlock(&init_mm.page_table_lock);
296 return err;
297}
298
299/*
300 * Map in all of physical memory starting at KERNELBASE.
301 */
302void __init mapin_ram(void)
303{
304 unsigned long v, p, s, f;
305
306 s = mmu_mapin_ram();
307 v = KERNELBASE + s;
308 p = PPC_MEMSTART + s;
309 for (; s < total_lowmem; s += PAGE_SIZE) {
310 if ((char *) v >= _stext && (char *) v < etext)
311 f = _PAGE_RAM_TEXT;
312 else
313 f = _PAGE_RAM;
314 map_page(v, p, f);
315 v += PAGE_SIZE;
316 p += PAGE_SIZE;
317 }
318}
319
320/* is x a power of 2? */
321#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
322
323/* is x a power of 4? */
324#define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1))
325
326/*
327 * Set up a mapping for a block of I/O.
328 * virt, phys, size must all be page-aligned.
329 * This should only be called before ioremap is called.
330 */
331void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
332 unsigned int size, int flags)
333{
334 int i;
335
336 if (virt > KERNELBASE && virt < ioremap_bot)
337 ioremap_bot = ioremap_base = virt;
338
339#ifdef HAVE_BATS
340 /*
341 * Use a BAT for this if possible...
342 */
343 if (io_bat_index < 2 && is_power_of_2(size)
344 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
345 setbat(io_bat_index, virt, phys, size, flags);
346 ++io_bat_index;
347 return;
348 }
349#endif /* HAVE_BATS */
350
351#ifdef HAVE_TLBCAM
352 /*
353 * Use a CAM for this if possible...
354 */
355 if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size)
356 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
357 settlbcam(tlbcam_index, virt, phys, size, flags, 0);
358 ++tlbcam_index;
359 return;
360 }
361#endif /* HAVE_TLBCAM */
362
363 /* No BATs available, put it in the page tables. */
364 for (i = 0; i < size; i += PAGE_SIZE)
365 map_page(virt + i, phys + i, flags);
366}
367
368/* Scan the real Linux page tables and return a PTE pointer for
369 * a virtual address in a context.
370 * Returns true (1) if PTE was found, zero otherwise. The pointer to
371 * the PTE pointer is unmodified if PTE is not found.
372 */
373int
374get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
375{
376 pgd_t *pgd;
377 pmd_t *pmd;
378 pte_t *pte;
379 int retval = 0;
380
381 pgd = pgd_offset(mm, addr & PAGE_MASK);
382 if (pgd) {
383 pmd = pmd_offset(pgd, addr & PAGE_MASK);
384 if (pmd_present(*pmd)) {
385 pte = pte_offset_map(pmd, addr & PAGE_MASK);
386 if (pte) {
387 retval = 1;
388 *ptep = pte;
389 /* XXX caller needs to do pte_unmap, yuck */
390 }
391 }
392 }
393 return(retval);
394}
395
396/* Find physical address for this virtual address. Normally used by
397 * I/O functions, but anyone can call it.
398 */
399unsigned long iopa(unsigned long addr)
400{
401 unsigned long pa;
402
403 /* I don't know why this won't work on PMacs or CHRP. It
404 * appears there is some bug, or there is some implicit
405 * mapping done not properly represented by BATs or in page
406 * tables.......I am actively working on resolving this, but
407 * can't hold up other stuff. -- Dan
408 */
409 pte_t *pte;
410 struct mm_struct *mm;
411
412 /* Check the BATs */
413 pa = v_mapped_by_bats(addr);
414 if (pa)
415 return pa;
416
417 /* Allow mapping of user addresses (within the thread)
418 * for DMA if necessary.
419 */
420 if (addr < TASK_SIZE)
421 mm = current->mm;
422 else
423 mm = &init_mm;
424
425 pa = 0;
426 if (get_pteptr(mm, addr, &pte)) {
427 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
428 pte_unmap(pte);
429 }
430
431 return(pa);
432}
433
434/* This is will find the virtual address for a physical one....
435 * Swiped from APUS, could be dangerous :-).
436 * This is only a placeholder until I really find a way to make this
437 * work. -- Dan
438 */
439unsigned long
440mm_ptov (unsigned long paddr)
441{
442 unsigned long ret;
443#if 0
444 if (paddr < 16*1024*1024)
445 ret = ZTWO_VADDR(paddr);
446 else {
447 int i;
448
449 for (i = 0; i < kmap_chunk_count;){
450 unsigned long phys = kmap_chunks[i++];
451 unsigned long size = kmap_chunks[i++];
452 unsigned long virt = kmap_chunks[i++];
453 if (paddr >= phys
454 && paddr < (phys + size)){
455 ret = virt + paddr - phys;
456 goto exit;
457 }
458 }
459
460 ret = (unsigned long) __va(paddr);
461 }
462exit:
463#ifdef DEBUGPV
464 printk ("PTOV(%lx)=%lx\n", paddr, ret);
465#endif
466#else
467 ret = (unsigned long)paddr + KERNELBASE;
468#endif
469 return ret;
470}
471