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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * PowerPC version
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
6 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
7 * Copyright (C) 1996 Paul Mackerras
8 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
9 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
10 *
11 * Derived from "arch/i386/mm/init.c"
12 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21#include <linux/config.h>
22#include <linux/module.h>
23#include <linux/sched.h>
24#include <linux/kernel.h>
25#include <linux/errno.h>
26#include <linux/string.h>
27#include <linux/types.h>
28#include <linux/mm.h>
29#include <linux/stddef.h>
30#include <linux/init.h>
31#include <linux/bootmem.h>
32#include <linux/highmem.h>
33#include <linux/initrd.h>
34#include <linux/pagemap.h>
35
36#include <asm/pgalloc.h>
37#include <asm/prom.h>
38#include <asm/io.h>
39#include <asm/mmu_context.h>
40#include <asm/pgtable.h>
41#include <asm/mmu.h>
42#include <asm/smp.h>
43#include <asm/machdep.h>
44#include <asm/btext.h>
45#include <asm/tlb.h>
46#include <asm/bootinfo.h>
47
48#include "mem_pieces.h"
49#include "mmu_decl.h"
50
51#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
52/* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */
53#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE))
54#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
55#endif
56#endif
57#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
58
59DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
60
61unsigned long total_memory;
62unsigned long total_lowmem;
63
64unsigned long ppc_memstart;
65unsigned long ppc_memoffset = PAGE_OFFSET;
66
67int mem_init_done;
68int init_bootmem_done;
69int boot_mapsize;
70#ifdef CONFIG_PPC_PMAC
71unsigned long agp_special_page;
72#endif
73
74extern char _end[];
75extern char etext[], _stext[];
76extern char __init_begin, __init_end;
77extern char __prep_begin, __prep_end;
78extern char __chrp_begin, __chrp_end;
79extern char __pmac_begin, __pmac_end;
80extern char __openfirmware_begin, __openfirmware_end;
81
82#ifdef CONFIG_HIGHMEM
83pte_t *kmap_pte;
84pgprot_t kmap_prot;
85
86EXPORT_SYMBOL(kmap_prot);
87EXPORT_SYMBOL(kmap_pte);
88#endif
89
90void MMU_init(void);
91void set_phys_avail(unsigned long total_ram);
92
93/* XXX should be in current.h -- paulus */
94extern struct task_struct *current_set[NR_CPUS];
95
96char *klimit = _end;
97struct mem_pieces phys_avail;
98
99extern char *sysmap;
100extern unsigned long sysmap_size;
101
102/*
103 * this tells the system to map all of ram with the segregs
104 * (i.e. page tables) instead of the bats.
105 * -- Cort
106 */
107int __map_without_bats;
108int __map_without_ltlbs;
109
110/* max amount of RAM to use */
111unsigned long __max_memory;
112/* max amount of low RAM to map in */
113unsigned long __max_low_memory = MAX_LOW_MEM;
114
115void show_mem(void)
116{
117 int i,free = 0,total = 0,reserved = 0;
118 int shared = 0, cached = 0;
119 int highmem = 0;
120
121 printk("Mem-info:\n");
122 show_free_areas();
123 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
124 i = max_mapnr;
125 while (i-- > 0) {
126 total++;
127 if (PageHighMem(mem_map+i))
128 highmem++;
129 if (PageReserved(mem_map+i))
130 reserved++;
131 else if (PageSwapCache(mem_map+i))
132 cached++;
133 else if (!page_count(mem_map+i))
134 free++;
135 else
136 shared += page_count(mem_map+i) - 1;
137 }
138 printk("%d pages of RAM\n",total);
139 printk("%d pages of HIGHMEM\n", highmem);
140 printk("%d free pages\n",free);
141 printk("%d reserved pages\n",reserved);
142 printk("%d pages shared\n",shared);
143 printk("%d pages swap cached\n",cached);
144}
145
146/* Free up now-unused memory */
147static void free_sec(unsigned long start, unsigned long end, const char *name)
148{
149 unsigned long cnt = 0;
150
151 while (start < end) {
152 ClearPageReserved(virt_to_page(start));
153 set_page_count(virt_to_page(start), 1);
154 free_page(start);
155 cnt++;
156 start += PAGE_SIZE;
157 }
158 if (cnt) {
159 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
160 totalram_pages += cnt;
161 }
162}
163
164void free_initmem(void)
165{
166#define FREESEC(TYPE) \
167 free_sec((unsigned long)(&__ ## TYPE ## _begin), \
168 (unsigned long)(&__ ## TYPE ## _end), \
169 #TYPE);
170
171 printk ("Freeing unused kernel memory:");
172 FREESEC(init);
173 if (_machine != _MACH_Pmac)
174 FREESEC(pmac);
175 if (_machine != _MACH_chrp)
176 FREESEC(chrp);
177 if (_machine != _MACH_prep)
178 FREESEC(prep);
179 if (!have_of)
180 FREESEC(openfirmware);
181 printk("\n");
182#undef FREESEC
183}
184
185#ifdef CONFIG_BLK_DEV_INITRD
186void free_initrd_mem(unsigned long start, unsigned long end)
187{
188 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
189
190 for (; start < end; start += PAGE_SIZE) {
191 ClearPageReserved(virt_to_page(start));
192 set_page_count(virt_to_page(start), 1);
193 free_page(start);
194 totalram_pages++;
195 }
196}
197#endif
198
199/*
200 * Check for command-line options that affect what MMU_init will do.
201 */
202void MMU_setup(void)
203{
204 /* Check for nobats option (used in mapin_ram). */
205 if (strstr(cmd_line, "nobats")) {
206 __map_without_bats = 1;
207 }
208
209 if (strstr(cmd_line, "noltlbs")) {
210 __map_without_ltlbs = 1;
211 }
212
213 /* Look for mem= option on command line */
214 if (strstr(cmd_line, "mem=")) {
215 char *p, *q;
216 unsigned long maxmem = 0;
217
218 for (q = cmd_line; (p = strstr(q, "mem=")) != 0; ) {
219 q = p + 4;
220 if (p > cmd_line && p[-1] != ' ')
221 continue;
222 maxmem = simple_strtoul(q, &q, 0);
223 if (*q == 'k' || *q == 'K') {
224 maxmem <<= 10;
225 ++q;
226 } else if (*q == 'm' || *q == 'M') {
227 maxmem <<= 20;
228 ++q;
229 }
230 }
231 __max_memory = maxmem;
232 }
233}
234
235/*
236 * MMU_init sets up the basic memory mappings for the kernel,
237 * including both RAM and possibly some I/O regions,
238 * and sets up the page tables and the MMU hardware ready to go.
239 */
240void __init MMU_init(void)
241{
242 if (ppc_md.progress)
243 ppc_md.progress("MMU:enter", 0x111);
244
245 /* parse args from command line */
246 MMU_setup();
247
248 /*
249 * Figure out how much memory we have, how much
250 * is lowmem, and how much is highmem. If we were
251 * passed the total memory size from the bootloader,
252 * just use it.
253 */
254 if (boot_mem_size)
255 total_memory = boot_mem_size;
256 else
257 total_memory = ppc_md.find_end_of_memory();
258
259 if (__max_memory && total_memory > __max_memory)
260 total_memory = __max_memory;
261 total_lowmem = total_memory;
262#ifdef CONFIG_FSL_BOOKE
263 /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
264 * entries, so we need to adjust lowmem to match the amount we can map
265 * in the fixed entries */
266 adjust_total_lowmem();
267#endif /* CONFIG_FSL_BOOKE */
268 if (total_lowmem > __max_low_memory) {
269 total_lowmem = __max_low_memory;
270#ifndef CONFIG_HIGHMEM
271 total_memory = total_lowmem;
272#endif /* CONFIG_HIGHMEM */
273 }
274 set_phys_avail(total_lowmem);
275
276 /* Initialize the MMU hardware */
277 if (ppc_md.progress)
278 ppc_md.progress("MMU:hw init", 0x300);
279 MMU_init_hw();
280
281 /* Map in all of RAM starting at KERNELBASE */
282 if (ppc_md.progress)
283 ppc_md.progress("MMU:mapin", 0x301);
284 mapin_ram();
285
286#ifdef CONFIG_HIGHMEM
287 ioremap_base = PKMAP_BASE;
288#else
289 ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
290#endif /* CONFIG_HIGHMEM */
291 ioremap_bot = ioremap_base;
292
293 /* Map in I/O resources */
294 if (ppc_md.progress)
295 ppc_md.progress("MMU:setio", 0x302);
296 if (ppc_md.setup_io_mappings)
297 ppc_md.setup_io_mappings();
298
299 /* Initialize the context management stuff */
300 mmu_context_init();
301
302 if (ppc_md.progress)
303 ppc_md.progress("MMU:exit", 0x211);
304
305#ifdef CONFIG_BOOTX_TEXT
306 /* By default, we are no longer mapped */
307 boot_text_mapped = 0;
308 /* Must be done last, or ppc_md.progress will die. */
309 map_boot_text();
310#endif
311}
312
313/* This is only called until mem_init is done. */
314void __init *early_get_page(void)
315{
316 void *p;
317
318 if (init_bootmem_done) {
319 p = alloc_bootmem_pages(PAGE_SIZE);
320 } else {
321 p = mem_pieces_find(PAGE_SIZE, PAGE_SIZE);
322 }
323 return p;
324}
325
326/*
327 * Initialize the bootmem system and give it all the memory we
328 * have available.
329 */
330void __init do_init_bootmem(void)
331{
332 unsigned long start, size;
333 int i;
334
335 /*
336 * Find an area to use for the bootmem bitmap.
337 * We look for the first area which is at least
338 * 128kB in length (128kB is enough for a bitmap
339 * for 4GB of memory, using 4kB pages), plus 1 page
340 * (in case the address isn't page-aligned).
341 */
342 start = 0;
343 size = 0;
344 for (i = 0; i < phys_avail.n_regions; ++i) {
345 unsigned long a = phys_avail.regions[i].address;
346 unsigned long s = phys_avail.regions[i].size;
347 if (s <= size)
348 continue;
349 start = a;
350 size = s;
351 if (s >= 33 * PAGE_SIZE)
352 break;
353 }
354 start = PAGE_ALIGN(start);
355
356 min_low_pfn = start >> PAGE_SHIFT;
357 max_low_pfn = (PPC_MEMSTART + total_lowmem) >> PAGE_SHIFT;
358 max_pfn = (PPC_MEMSTART + total_memory) >> PAGE_SHIFT;
359 boot_mapsize = init_bootmem_node(&contig_page_data, min_low_pfn,
360 PPC_MEMSTART >> PAGE_SHIFT,
361 max_low_pfn);
362
363 /* remove the bootmem bitmap from the available memory */
364 mem_pieces_remove(&phys_avail, start, boot_mapsize, 1);
365
366 /* add everything in phys_avail into the bootmem map */
367 for (i = 0; i < phys_avail.n_regions; ++i)
368 free_bootmem(phys_avail.regions[i].address,
369 phys_avail.regions[i].size);
370
371 init_bootmem_done = 1;
372}
373
374/*
375 * paging_init() sets up the page tables - in fact we've already done this.
376 */
377void __init paging_init(void)
378{
379 unsigned long zones_size[MAX_NR_ZONES], i;
380
381#ifdef CONFIG_HIGHMEM
382 map_page(PKMAP_BASE, 0, 0); /* XXX gross */
383 pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
384 (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
385 map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
386 kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
387 (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
388 kmap_prot = PAGE_KERNEL;
389#endif /* CONFIG_HIGHMEM */
390
391 /*
392 * All pages are DMA-able so we put them all in the DMA zone.
393 */
394 zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
395 for (i = 1; i < MAX_NR_ZONES; i++)
396 zones_size[i] = 0;
397
398#ifdef CONFIG_HIGHMEM
399 zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
400#endif /* CONFIG_HIGHMEM */
401
402 free_area_init(zones_size);
403}
404
405void __init mem_init(void)
406{
407 unsigned long addr;
408 int codepages = 0;
409 int datapages = 0;
410 int initpages = 0;
411#ifdef CONFIG_HIGHMEM
412 unsigned long highmem_mapnr;
413
414 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
415#endif /* CONFIG_HIGHMEM */
416 max_mapnr = total_memory >> PAGE_SHIFT;
417
418 high_memory = (void *) __va(PPC_MEMSTART + total_lowmem);
419 num_physpages = max_mapnr; /* RAM is assumed contiguous */
420
421 totalram_pages += free_all_bootmem();
422
423#ifdef CONFIG_BLK_DEV_INITRD
424 /* if we are booted from BootX with an initial ramdisk,
425 make sure the ramdisk pages aren't reserved. */
426 if (initrd_start) {
427 for (addr = initrd_start; addr < initrd_end; addr += PAGE_SIZE)
428 ClearPageReserved(virt_to_page(addr));
429 }
430#endif /* CONFIG_BLK_DEV_INITRD */
431
432#ifdef CONFIG_PPC_OF
433 /* mark the RTAS pages as reserved */
434 if ( rtas_data )
435 for (addr = (ulong)__va(rtas_data);
436 addr < PAGE_ALIGN((ulong)__va(rtas_data)+rtas_size) ;
437 addr += PAGE_SIZE)
438 SetPageReserved(virt_to_page(addr));
439#endif
440#ifdef CONFIG_PPC_PMAC
441 if (agp_special_page)
442 SetPageReserved(virt_to_page(agp_special_page));
443#endif
444 if ( sysmap )
445 for (addr = (unsigned long)sysmap;
446 addr < PAGE_ALIGN((unsigned long)sysmap+sysmap_size) ;
447 addr += PAGE_SIZE)
448 SetPageReserved(virt_to_page(addr));
449
450 for (addr = PAGE_OFFSET; addr < (unsigned long)high_memory;
451 addr += PAGE_SIZE) {
452 if (!PageReserved(virt_to_page(addr)))
453 continue;
454 if (addr < (ulong) etext)
455 codepages++;
456 else if (addr >= (unsigned long)&__init_begin
457 && addr < (unsigned long)&__init_end)
458 initpages++;
459 else if (addr < (ulong) klimit)
460 datapages++;
461 }
462
463#ifdef CONFIG_HIGHMEM
464 {
465 unsigned long pfn;
466
467 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
468 struct page *page = mem_map + pfn;
469
470 ClearPageReserved(page);
471 set_bit(PG_highmem, &page->flags);
472 set_page_count(page, 1);
473 __free_page(page);
474 totalhigh_pages++;
475 }
476 totalram_pages += totalhigh_pages;
477 }
478#endif /* CONFIG_HIGHMEM */
479
480 printk("Memory: %luk available (%dk kernel code, %dk data, %dk init, %ldk highmem)\n",
481 (unsigned long)nr_free_pages()<< (PAGE_SHIFT-10),
482 codepages<< (PAGE_SHIFT-10), datapages<< (PAGE_SHIFT-10),
483 initpages<< (PAGE_SHIFT-10),
484 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
485 if (sysmap)
486 printk("System.map loaded at 0x%08x for debugger, size: %ld bytes\n",
487 (unsigned int)sysmap, sysmap_size);
488#ifdef CONFIG_PPC_PMAC
489 if (agp_special_page)
490 printk(KERN_INFO "AGP special page: 0x%08lx\n", agp_special_page);
491#endif
492
493 mem_init_done = 1;
494}
495
496/*
497 * Set phys_avail to the amount of physical memory,
498 * less the kernel text/data/bss.
499 */
500void __init
501set_phys_avail(unsigned long total_memory)
502{
503 unsigned long kstart, ksize;
504
505 /*
506 * Initially, available physical memory is equivalent to all
507 * physical memory.
508 */
509
510 phys_avail.regions[0].address = PPC_MEMSTART;
511 phys_avail.regions[0].size = total_memory;
512 phys_avail.n_regions = 1;
513
514 /*
515 * Map out the kernel text/data/bss from the available physical
516 * memory.
517 */
518
519 kstart = __pa(_stext); /* should be 0 */
520 ksize = PAGE_ALIGN(klimit - _stext);
521
522 mem_pieces_remove(&phys_avail, kstart, ksize, 0);
523 mem_pieces_remove(&phys_avail, 0, 0x4000, 0);
524
525#if defined(CONFIG_BLK_DEV_INITRD)
526 /* Remove the init RAM disk from the available memory. */
527 if (initrd_start) {
528 mem_pieces_remove(&phys_avail, __pa(initrd_start),
529 initrd_end - initrd_start, 1);
530 }
531#endif /* CONFIG_BLK_DEV_INITRD */
532#ifdef CONFIG_PPC_OF
533 /* remove the RTAS pages from the available memory */
534 if (rtas_data)
535 mem_pieces_remove(&phys_avail, rtas_data, rtas_size, 1);
536#endif
537 /* remove the sysmap pages from the available memory */
538 if (sysmap)
539 mem_pieces_remove(&phys_avail, __pa(sysmap), sysmap_size, 1);
540#ifdef CONFIG_PPC_PMAC
541 /* Because of some uninorth weirdness, we need a page of
542 * memory as high as possible (it must be outside of the
543 * bus address seen as the AGP aperture). It will be used
544 * by the r128 DRM driver
545 *
546 * FIXME: We need to make sure that page doesn't overlap any of the\
547 * above. This could be done by improving mem_pieces_find to be able
548 * to do a backward search from the end of the list.
549 */
550 if (_machine == _MACH_Pmac && find_devices("uni-north-agp")) {
551 agp_special_page = (total_memory - PAGE_SIZE);
552 mem_pieces_remove(&phys_avail, agp_special_page, PAGE_SIZE, 0);
553 agp_special_page = (unsigned long)__va(agp_special_page);
554 }
555#endif /* CONFIG_PPC_PMAC */
556}
557
558/* Mark some memory as reserved by removing it from phys_avail. */
559void __init reserve_phys_mem(unsigned long start, unsigned long size)
560{
561 mem_pieces_remove(&phys_avail, start, size, 1);
562}
563
564/*
565 * This is called when a page has been modified by the kernel.
566 * It just marks the page as not i-cache clean. We do the i-cache
567 * flush later when the page is given to a user process, if necessary.
568 */
569void flush_dcache_page(struct page *page)
570{
571 clear_bit(PG_arch_1, &page->flags);
572}
573
574void flush_dcache_icache_page(struct page *page)
575{
576#ifdef CONFIG_BOOKE
577 __flush_dcache_icache(kmap(page));
578 kunmap(page);
579#else
580 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
581#endif
582
583}
584void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
585{
586 clear_page(page);
587 clear_bit(PG_arch_1, &pg->flags);
588}
589
590void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
591 struct page *pg)
592{
593 copy_page(vto, vfrom);
594 clear_bit(PG_arch_1, &pg->flags);
595}
596
597void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
598 unsigned long addr, int len)
599{
600 unsigned long maddr;
601
602 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
603 flush_icache_range(maddr, maddr + len);
604 kunmap(page);
605}
606
607/*
608 * This is called at the end of handling a user page fault, when the
609 * fault has been handled by updating a PTE in the linux page tables.
610 * We use it to preload an HPTE into the hash table corresponding to
611 * the updated linux PTE.
612 */
613void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
614 pte_t pte)
615{
616 /* handle i-cache coherency */
617 unsigned long pfn = pte_pfn(pte);
618
619 if (pfn_valid(pfn)) {
620 struct page *page = pfn_to_page(pfn);
621 if (!PageReserved(page)
622 && !test_bit(PG_arch_1, &page->flags)) {
623 if (vma->vm_mm == current->active_mm)
624 __flush_dcache_icache((void *) address);
625 else
626 flush_dcache_icache_page(page);
627 set_bit(PG_arch_1, &page->flags);
628 }
629 }
630
631#ifdef CONFIG_PPC_STD_MMU
632 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
633 if (Hash != 0 && pte_young(pte)) {
634 struct mm_struct *mm;
635 pmd_t *pmd;
636
637 mm = (address < TASK_SIZE)? vma->vm_mm: &init_mm;
638 pmd = pmd_offset(pgd_offset(mm, address), address);
639 if (!pmd_none(*pmd))
640 add_hash_page(mm->context, address, pmd_val(*pmd));
641 }
642#endif
643}
644
645/*
646 * This is called by /dev/mem to know if a given address has to
647 * be mapped non-cacheable or not
648 */
649int page_is_ram(unsigned long pfn)
650{
651 unsigned long paddr = (pfn << PAGE_SHIFT);
652
653 return paddr < __pa(high_memory);
654}
655
656pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
657 unsigned long size, pgprot_t vma_prot)
658{
659 if (ppc_md.phys_mem_access_prot)
660 return ppc_md.phys_mem_access_prot(file, addr, size, vma_prot);
661
662 if (!page_is_ram(addr >> PAGE_SHIFT))
663 vma_prot = __pgprot(pgprot_val(vma_prot)
664 | _PAGE_GUARDED | _PAGE_NO_CACHE);
665 return vma_prot;
666}
667EXPORT_SYMBOL(phys_mem_access_prot);