Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux-2.6] / arch / powerpc / mm / mem.c
1 /*
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  *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
9  *
10  *  Derived from "arch/i386/mm/init.c"
11  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
12  *
13  *  This program is free software; you can redistribute it and/or
14  *  modify it under the terms of the GNU General Public License
15  *  as published by the Free Software Foundation; either version
16  *  2 of the License, or (at your option) any later version.
17  *
18  */
19
20 #include <linux/module.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/string.h>
25 #include <linux/types.h>
26 #include <linux/mm.h>
27 #include <linux/stddef.h>
28 #include <linux/init.h>
29 #include <linux/bootmem.h>
30 #include <linux/highmem.h>
31 #include <linux/initrd.h>
32 #include <linux/pagemap.h>
33 #include <linux/suspend.h>
34 #include <linux/lmb.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/sections.h>
47 #include <asm/vdso.h>
48
49 #include "mmu_decl.h"
50
51 #ifndef CPU_FTR_COHERENT_ICACHE
52 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
53 #define CPU_FTR_NOEXECUTE       0
54 #endif
55
56 int init_bootmem_done;
57 int mem_init_done;
58 unsigned long memory_limit;
59
60 int page_is_ram(unsigned long pfn)
61 {
62         unsigned long paddr = (pfn << PAGE_SHIFT);
63
64 #ifndef CONFIG_PPC64    /* XXX for now */
65         return paddr < __pa(high_memory);
66 #else
67         int i;
68         for (i=0; i < lmb.memory.cnt; i++) {
69                 unsigned long base;
70
71                 base = lmb.memory.region[i].base;
72
73                 if ((paddr >= base) &&
74                         (paddr < (base + lmb.memory.region[i].size))) {
75                         return 1;
76                 }
77         }
78
79         return 0;
80 #endif
81 }
82
83 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
84                               unsigned long size, pgprot_t vma_prot)
85 {
86         if (ppc_md.phys_mem_access_prot)
87                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
88
89         if (!page_is_ram(pfn))
90                 vma_prot = __pgprot(pgprot_val(vma_prot)
91                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
92         return vma_prot;
93 }
94 EXPORT_SYMBOL(phys_mem_access_prot);
95
96 #ifdef CONFIG_MEMORY_HOTPLUG
97
98 void online_page(struct page *page)
99 {
100         ClearPageReserved(page);
101         init_page_count(page);
102         __free_page(page);
103         totalram_pages++;
104         num_physpages++;
105 }
106
107 #ifdef CONFIG_NUMA
108 int memory_add_physaddr_to_nid(u64 start)
109 {
110         return hot_add_scn_to_nid(start);
111 }
112 #endif
113
114 int arch_add_memory(int nid, u64 start, u64 size)
115 {
116         struct pglist_data *pgdata;
117         struct zone *zone;
118         unsigned long start_pfn = start >> PAGE_SHIFT;
119         unsigned long nr_pages = size >> PAGE_SHIFT;
120
121         pgdata = NODE_DATA(nid);
122
123         start = (unsigned long)__va(start);
124         create_section_mapping(start, start + size);
125
126         /* this should work for most non-highmem platforms */
127         zone = pgdata->node_zones;
128
129         return __add_pages(zone, start_pfn, nr_pages);
130 }
131
132 #ifdef CONFIG_MEMORY_HOTREMOVE
133 int remove_memory(u64 start, u64 size)
134 {
135         unsigned long start_pfn, end_pfn;
136         int ret;
137
138         start_pfn = start >> PAGE_SHIFT;
139         end_pfn = start_pfn + (size >> PAGE_SHIFT);
140         ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
141         if (ret)
142                 goto out;
143         /* Arch-specific calls go here - next patch */
144 out:
145         return ret;
146 }
147 #endif /* CONFIG_MEMORY_HOTREMOVE */
148
149 /*
150  * walk_memory_resource() needs to make sure there is no holes in a given
151  * memory range. On PPC64, since this range comes from /sysfs, the range
152  * is guaranteed to be valid, non-overlapping and can not contain any
153  * holes. By the time we get here (memory add or remove), /proc/device-tree
154  * is updated and correct. Only reason we need to check against device-tree
155  * would be if we allow user-land to specify a memory range through a
156  * system call/ioctl etc. instead of doing offline/online through /sysfs.
157  */
158 int
159 walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
160                         int (*func)(unsigned long, unsigned long, void *))
161 {
162         return  (*func)(start_pfn, nr_pages, arg);
163 }
164
165 #endif /* CONFIG_MEMORY_HOTPLUG */
166
167 void show_mem(void)
168 {
169         unsigned long total = 0, reserved = 0;
170         unsigned long shared = 0, cached = 0;
171         unsigned long highmem = 0;
172         struct page *page;
173         pg_data_t *pgdat;
174         unsigned long i;
175
176         printk("Mem-info:\n");
177         show_free_areas();
178         for_each_online_pgdat(pgdat) {
179                 unsigned long flags;
180                 pgdat_resize_lock(pgdat, &flags);
181                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
182                         if (!pfn_valid(pgdat->node_start_pfn + i))
183                                 continue;
184                         page = pgdat_page_nr(pgdat, i);
185                         total++;
186                         if (PageHighMem(page))
187                                 highmem++;
188                         if (PageReserved(page))
189                                 reserved++;
190                         else if (PageSwapCache(page))
191                                 cached++;
192                         else if (page_count(page))
193                                 shared += page_count(page) - 1;
194                 }
195                 pgdat_resize_unlock(pgdat, &flags);
196         }
197         printk("%ld pages of RAM\n", total);
198 #ifdef CONFIG_HIGHMEM
199         printk("%ld pages of HIGHMEM\n", highmem);
200 #endif
201         printk("%ld reserved pages\n", reserved);
202         printk("%ld pages shared\n", shared);
203         printk("%ld pages swap cached\n", cached);
204 }
205
206 /*
207  * Initialize the bootmem system and give it all the memory we
208  * have available.  If we are using highmem, we only put the
209  * lowmem into the bootmem system.
210  */
211 #ifndef CONFIG_NEED_MULTIPLE_NODES
212 void __init do_init_bootmem(void)
213 {
214         unsigned long i;
215         unsigned long start, bootmap_pages;
216         unsigned long total_pages;
217         int boot_mapsize;
218
219         max_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
220         total_pages = (lmb_end_of_DRAM() - memstart_addr) >> PAGE_SHIFT;
221 #ifdef CONFIG_HIGHMEM
222         total_pages = total_lowmem >> PAGE_SHIFT;
223         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
224 #endif
225
226         /*
227          * Find an area to use for the bootmem bitmap.  Calculate the size of
228          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
229          * Add 1 additional page in case the address isn't page-aligned.
230          */
231         bootmap_pages = bootmem_bootmap_pages(total_pages);
232
233         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
234
235         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
236
237         /* Add active regions with valid PFNs */
238         for (i = 0; i < lmb.memory.cnt; i++) {
239                 unsigned long start_pfn, end_pfn;
240                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
241                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
242                 add_active_range(0, start_pfn, end_pfn);
243         }
244
245         /* Add all physical memory to the bootmem map, mark each area
246          * present.
247          */
248 #ifdef CONFIG_HIGHMEM
249         free_bootmem_with_active_regions(0, lowmem_end_addr >> PAGE_SHIFT);
250
251         /* reserve the sections we're already using */
252         for (i = 0; i < lmb.reserved.cnt; i++) {
253                 unsigned long addr = lmb.reserved.region[i].base +
254                                      lmb_size_bytes(&lmb.reserved, i) - 1;
255                 if (addr < lowmem_end_addr)
256                         reserve_bootmem(lmb.reserved.region[i].base,
257                                         lmb_size_bytes(&lmb.reserved, i),
258                                         BOOTMEM_DEFAULT);
259                 else if (lmb.reserved.region[i].base < lowmem_end_addr) {
260                         unsigned long adjusted_size = lowmem_end_addr -
261                                       lmb.reserved.region[i].base;
262                         reserve_bootmem(lmb.reserved.region[i].base,
263                                         adjusted_size, BOOTMEM_DEFAULT);
264                 }
265         }
266 #else
267         free_bootmem_with_active_regions(0, max_pfn);
268
269         /* reserve the sections we're already using */
270         for (i = 0; i < lmb.reserved.cnt; i++)
271                 reserve_bootmem(lmb.reserved.region[i].base,
272                                 lmb_size_bytes(&lmb.reserved, i),
273                                 BOOTMEM_DEFAULT);
274
275 #endif
276         /* XXX need to clip this if using highmem? */
277         sparse_memory_present_with_active_regions(0);
278
279         init_bootmem_done = 1;
280 }
281
282 /* mark pages that don't exist as nosave */
283 static int __init mark_nonram_nosave(void)
284 {
285         unsigned long lmb_next_region_start_pfn,
286                       lmb_region_max_pfn;
287         int i;
288
289         for (i = 0; i < lmb.memory.cnt - 1; i++) {
290                 lmb_region_max_pfn =
291                         (lmb.memory.region[i].base >> PAGE_SHIFT) +
292                         (lmb.memory.region[i].size >> PAGE_SHIFT);
293                 lmb_next_region_start_pfn =
294                         lmb.memory.region[i+1].base >> PAGE_SHIFT;
295
296                 if (lmb_region_max_pfn < lmb_next_region_start_pfn)
297                         register_nosave_region(lmb_region_max_pfn,
298                                                lmb_next_region_start_pfn);
299         }
300
301         return 0;
302 }
303
304 /*
305  * paging_init() sets up the page tables - in fact we've already done this.
306  */
307 void __init paging_init(void)
308 {
309         unsigned long total_ram = lmb_phys_mem_size();
310         unsigned long top_of_ram = lmb_end_of_DRAM();
311         unsigned long max_zone_pfns[MAX_NR_ZONES];
312
313 #ifdef CONFIG_HIGHMEM
314         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
315         pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
316                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
317         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
318         kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
319                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
320                          KMAP_FIX_BEGIN);
321         kmap_prot = PAGE_KERNEL;
322 #endif /* CONFIG_HIGHMEM */
323
324         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
325                top_of_ram, total_ram);
326         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
327                (top_of_ram - total_ram) >> 20);
328         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
329 #ifdef CONFIG_HIGHMEM
330         max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;
331         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
332 #else
333         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
334 #endif
335         free_area_init_nodes(max_zone_pfns);
336
337         mark_nonram_nosave();
338 }
339 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
340
341 void __init mem_init(void)
342 {
343 #ifdef CONFIG_NEED_MULTIPLE_NODES
344         int nid;
345 #endif
346         pg_data_t *pgdat;
347         unsigned long i;
348         struct page *page;
349         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
350
351         num_physpages = lmb.memory.size >> PAGE_SHIFT;
352         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
353
354 #ifdef CONFIG_NEED_MULTIPLE_NODES
355         for_each_online_node(nid) {
356                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
357                         printk("freeing bootmem node %d\n", nid);
358                         totalram_pages +=
359                                 free_all_bootmem_node(NODE_DATA(nid));
360                 }
361         }
362 #else
363         max_mapnr = max_pfn;
364         totalram_pages += free_all_bootmem();
365 #endif
366         for_each_online_pgdat(pgdat) {
367                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
368                         if (!pfn_valid(pgdat->node_start_pfn + i))
369                                 continue;
370                         page = pgdat_page_nr(pgdat, i);
371                         if (PageReserved(page))
372                                 reservedpages++;
373                 }
374         }
375
376         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
377         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
378         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
379         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
380
381 #ifdef CONFIG_HIGHMEM
382         {
383                 unsigned long pfn, highmem_mapnr;
384
385                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
386                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
387                         struct page *page = pfn_to_page(pfn);
388                         if (lmb_is_reserved(pfn << PAGE_SHIFT))
389                                 continue;
390                         ClearPageReserved(page);
391                         init_page_count(page);
392                         __free_page(page);
393                         totalhigh_pages++;
394                         reservedpages--;
395                 }
396                 totalram_pages += totalhigh_pages;
397                 printk(KERN_DEBUG "High memory: %luk\n",
398                        totalhigh_pages << (PAGE_SHIFT-10));
399         }
400 #endif /* CONFIG_HIGHMEM */
401
402         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
403                "%luk reserved, %luk data, %luk bss, %luk init)\n",
404                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
405                 num_physpages << (PAGE_SHIFT-10),
406                 codesize >> 10,
407                 reservedpages << (PAGE_SHIFT-10),
408                 datasize >> 10,
409                 bsssize >> 10,
410                 initsize >> 10);
411
412         mem_init_done = 1;
413 }
414
415 /*
416  * This is called when a page has been modified by the kernel.
417  * It just marks the page as not i-cache clean.  We do the i-cache
418  * flush later when the page is given to a user process, if necessary.
419  */
420 void flush_dcache_page(struct page *page)
421 {
422         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
423                 return;
424         /* avoid an atomic op if possible */
425         if (test_bit(PG_arch_1, &page->flags))
426                 clear_bit(PG_arch_1, &page->flags);
427 }
428 EXPORT_SYMBOL(flush_dcache_page);
429
430 void flush_dcache_icache_page(struct page *page)
431 {
432 #ifdef CONFIG_BOOKE
433         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
434         __flush_dcache_icache(start);
435         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
436 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
437         /* On 8xx there is no need to kmap since highmem is not supported */
438         __flush_dcache_icache(page_address(page)); 
439 #else
440         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
441 #endif
442
443 }
444 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
445 {
446         clear_page(page);
447
448         /*
449          * We shouldnt have to do this, but some versions of glibc
450          * require it (ld.so assumes zero filled pages are icache clean)
451          * - Anton
452          */
453         flush_dcache_page(pg);
454 }
455 EXPORT_SYMBOL(clear_user_page);
456
457 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
458                     struct page *pg)
459 {
460         copy_page(vto, vfrom);
461
462         /*
463          * We should be able to use the following optimisation, however
464          * there are two problems.
465          * Firstly a bug in some versions of binutils meant PLT sections
466          * were not marked executable.
467          * Secondly the first word in the GOT section is blrl, used
468          * to establish the GOT address. Until recently the GOT was
469          * not marked executable.
470          * - Anton
471          */
472 #if 0
473         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
474                 return;
475 #endif
476
477         flush_dcache_page(pg);
478 }
479
480 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
481                              unsigned long addr, int len)
482 {
483         unsigned long maddr;
484
485         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
486         flush_icache_range(maddr, maddr + len);
487         kunmap(page);
488 }
489 EXPORT_SYMBOL(flush_icache_user_range);
490
491 /*
492  * This is called at the end of handling a user page fault, when the
493  * fault has been handled by updating a PTE in the linux page tables.
494  * We use it to preload an HPTE into the hash table corresponding to
495  * the updated linux PTE.
496  * 
497  * This must always be called with the pte lock held.
498  */
499 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
500                       pte_t pte)
501 {
502 #ifdef CONFIG_PPC_STD_MMU
503         unsigned long access = 0, trap;
504 #endif
505         unsigned long pfn = pte_pfn(pte);
506
507         /* handle i-cache coherency */
508         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
509             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
510             pfn_valid(pfn)) {
511                 struct page *page = pfn_to_page(pfn);
512 #ifdef CONFIG_8xx
513                 /* On 8xx, cache control instructions (particularly
514                  * "dcbst" from flush_dcache_icache) fault as write
515                  * operation if there is an unpopulated TLB entry
516                  * for the address in question. To workaround that,
517                  * we invalidate the TLB here, thus avoiding dcbst
518                  * misbehaviour.
519                  */
520                 _tlbie(address, 0 /* 8xx doesn't care about PID */);
521 #endif
522                 /* The _PAGE_USER test should really be _PAGE_EXEC, but
523                  * older glibc versions execute some code from no-exec
524                  * pages, which for now we are supporting.  If exec-only
525                  * pages are ever implemented, this will have to change.
526                  */
527                 if (!PageReserved(page) && (pte_val(pte) & _PAGE_USER)
528                     && !test_bit(PG_arch_1, &page->flags)) {
529                         if (vma->vm_mm == current->active_mm) {
530                                 __flush_dcache_icache((void *) address);
531                         } else
532                                 flush_dcache_icache_page(page);
533                         set_bit(PG_arch_1, &page->flags);
534                 }
535         }
536
537 #ifdef CONFIG_PPC_STD_MMU
538         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
539         if (!pte_young(pte) || address >= TASK_SIZE)
540                 return;
541
542         /* We try to figure out if we are coming from an instruction
543          * access fault and pass that down to __hash_page so we avoid
544          * double-faulting on execution of fresh text. We have to test
545          * for regs NULL since init will get here first thing at boot
546          *
547          * We also avoid filling the hash if not coming from a fault
548          */
549         if (current->thread.regs == NULL)
550                 return;
551         trap = TRAP(current->thread.regs);
552         if (trap == 0x400)
553                 access |= _PAGE_EXEC;
554         else if (trap != 0x300)
555                 return;
556         hash_preload(vma->vm_mm, address, access, trap);
557 #endif /* CONFIG_PPC_STD_MMU */
558 }