e43e8ef7008812f817ba29fb81a1bf1ba30202f4
[linux-2.6.git] / 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  *  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/prom.h>
47 #include <asm/lmb.h>
48 #include <asm/sections.h>
49 #ifdef CONFIG_PPC64
50 #include <asm/vdso.h>
51 #endif
52
53 #include "mmu_decl.h"
54
55 #ifndef CPU_FTR_COHERENT_ICACHE
56 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
57 #define CPU_FTR_NOEXECUTE       0
58 #endif
59
60 int init_bootmem_done;
61 int mem_init_done;
62 unsigned long memory_limit;
63
64 /*
65  * This is called by /dev/mem to know if a given address has to
66  * be mapped non-cacheable or not
67  */
68 int page_is_ram(unsigned long pfn)
69 {
70         unsigned long paddr = (pfn << PAGE_SHIFT);
71
72 #ifndef CONFIG_PPC64    /* XXX for now */
73         return paddr < __pa(high_memory);
74 #else
75         int i;
76         for (i=0; i < lmb.memory.cnt; i++) {
77                 unsigned long base;
78
79                 base = lmb.memory.region[i].base;
80
81                 if ((paddr >= base) &&
82                         (paddr < (base + lmb.memory.region[i].size))) {
83                         return 1;
84                 }
85         }
86
87         return 0;
88 #endif
89 }
90 EXPORT_SYMBOL(page_is_ram);
91
92 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
93                               unsigned long size, pgprot_t vma_prot)
94 {
95         if (ppc_md.phys_mem_access_prot)
96                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
97
98         if (!page_is_ram(pfn))
99                 vma_prot = __pgprot(pgprot_val(vma_prot)
100                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
101         return vma_prot;
102 }
103 EXPORT_SYMBOL(phys_mem_access_prot);
104
105 void show_mem(void)
106 {
107         unsigned long total = 0, reserved = 0;
108         unsigned long shared = 0, cached = 0;
109         unsigned long highmem = 0;
110         struct page *page;
111         pg_data_t *pgdat;
112         unsigned long i;
113
114         printk("Mem-info:\n");
115         show_free_areas();
116         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
117         for_each_pgdat(pgdat) {
118                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
119                         page = pgdat_page_nr(pgdat, i);
120                         total++;
121                         if (PageHighMem(page))
122                                 highmem++;
123                         if (PageReserved(page))
124                                 reserved++;
125                         else if (PageSwapCache(page))
126                                 cached++;
127                         else if (page_count(page))
128                                 shared += page_count(page) - 1;
129                 }
130         }
131         printk("%ld pages of RAM\n", total);
132 #ifdef CONFIG_HIGHMEM
133         printk("%ld pages of HIGHMEM\n", highmem);
134 #endif
135         printk("%ld reserved pages\n", reserved);
136         printk("%ld pages shared\n", shared);
137         printk("%ld pages swap cached\n", cached);
138 }
139
140 /*
141  * Initialize the bootmem system and give it all the memory we
142  * have available.  If we are using highmem, we only put the
143  * lowmem into the bootmem system.
144  */
145 #ifndef CONFIG_NEED_MULTIPLE_NODES
146 void __init do_init_bootmem(void)
147 {
148         unsigned long i;
149         unsigned long start, bootmap_pages;
150         unsigned long total_pages;
151         int boot_mapsize;
152
153         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
154 #ifdef CONFIG_HIGHMEM
155         total_pages = total_lowmem >> PAGE_SHIFT;
156 #endif
157
158         /*
159          * Find an area to use for the bootmem bitmap.  Calculate the size of
160          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
161          * Add 1 additional page in case the address isn't page-aligned.
162          */
163         bootmap_pages = bootmem_bootmap_pages(total_pages);
164
165         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
166         BUG_ON(!start);
167
168         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
169
170         /* Add all physical memory to the bootmem map, mark each area
171          * present.
172          */
173         for (i = 0; i < lmb.memory.cnt; i++) {
174                 unsigned long base = lmb.memory.region[i].base;
175                 unsigned long size = lmb_size_bytes(&lmb.memory, i);
176 #ifdef CONFIG_HIGHMEM
177                 if (base >= total_lowmem)
178                         continue;
179                 if (base + size > total_lowmem)
180                         size = total_lowmem - base;
181 #endif
182                 free_bootmem(base, size);
183         }
184
185         /* reserve the sections we're already using */
186         for (i = 0; i < lmb.reserved.cnt; i++)
187                 reserve_bootmem(lmb.reserved.region[i].base,
188                                 lmb_size_bytes(&lmb.reserved, i));
189
190         /* XXX need to clip this if using highmem? */
191         for (i = 0; i < lmb.memory.cnt; i++)
192                 memory_present(0, lmb_start_pfn(&lmb.memory, i),
193                                lmb_end_pfn(&lmb.memory, i));
194         init_bootmem_done = 1;
195 }
196
197 /*
198  * paging_init() sets up the page tables - in fact we've already done this.
199  */
200 void __init paging_init(void)
201 {
202         unsigned long zones_size[MAX_NR_ZONES];
203         unsigned long zholes_size[MAX_NR_ZONES];
204         unsigned long total_ram = lmb_phys_mem_size();
205         unsigned long top_of_ram = lmb_end_of_DRAM();
206
207 #ifdef CONFIG_HIGHMEM
208         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
209         pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
210                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
211         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
212         kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
213                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
214         kmap_prot = PAGE_KERNEL;
215 #endif /* CONFIG_HIGHMEM */
216
217         printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
218                top_of_ram, total_ram);
219         printk(KERN_INFO "Memory hole size: %ldMB\n",
220                (top_of_ram - total_ram) >> 20);
221         /*
222          * All pages are DMA-able so we put them all in the DMA zone.
223          */
224         memset(zones_size, 0, sizeof(zones_size));
225         memset(zholes_size, 0, sizeof(zholes_size));
226
227         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
228         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
229
230 #ifdef CONFIG_HIGHMEM
231         zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
232         zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
233         zholes_size[ZONE_HIGHMEM] = (top_of_ram - total_ram) >> PAGE_SHIFT;
234 #else
235         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
236         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
237 #endif /* CONFIG_HIGHMEM */
238
239         free_area_init_node(0, NODE_DATA(0), zones_size,
240                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
241 }
242 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
243
244 void __init mem_init(void)
245 {
246 #ifdef CONFIG_NEED_MULTIPLE_NODES
247         int nid;
248 #endif
249         pg_data_t *pgdat;
250         unsigned long i;
251         struct page *page;
252         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
253
254         num_physpages = max_pfn;        /* RAM is assumed contiguous */
255         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
256
257 #ifdef CONFIG_NEED_MULTIPLE_NODES
258         for_each_online_node(nid) {
259                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
260                         printk("freeing bootmem node %x\n", nid);
261                         totalram_pages +=
262                                 free_all_bootmem_node(NODE_DATA(nid));
263                 }
264         }
265 #else
266         max_mapnr = num_physpages;
267         totalram_pages += free_all_bootmem();
268 #endif
269         for_each_pgdat(pgdat) {
270                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
271                         page = pgdat_page_nr(pgdat, i);
272                         if (PageReserved(page))
273                                 reservedpages++;
274                 }
275         }
276
277         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
278         datasize = (unsigned long)&__init_begin - (unsigned long)&_sdata;
279         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
280         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
281
282 #ifdef CONFIG_HIGHMEM
283         {
284                 unsigned long pfn, highmem_mapnr;
285
286                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
287                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
288                         struct page *page = pfn_to_page(pfn);
289
290                         ClearPageReserved(page);
291                         set_page_count(page, 1);
292                         __free_page(page);
293                         totalhigh_pages++;
294                 }
295                 totalram_pages += totalhigh_pages;
296                 printk(KERN_INFO "High memory: %luk\n",
297                        totalhigh_pages << (PAGE_SHIFT-10));
298         }
299 #endif /* CONFIG_HIGHMEM */
300
301         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
302                "%luk reserved, %luk data, %luk bss, %luk init)\n",
303                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
304                 num_physpages << (PAGE_SHIFT-10),
305                 codesize >> 10,
306                 reservedpages << (PAGE_SHIFT-10),
307                 datasize >> 10,
308                 bsssize >> 10,
309                 initsize >> 10);
310
311         mem_init_done = 1;
312
313 #ifdef CONFIG_PPC64
314         /* Initialize the vDSO */
315         vdso_init();
316 #endif
317 }
318
319 /*
320  * This is called when a page has been modified by the kernel.
321  * It just marks the page as not i-cache clean.  We do the i-cache
322  * flush later when the page is given to a user process, if necessary.
323  */
324 void flush_dcache_page(struct page *page)
325 {
326         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
327                 return;
328         /* avoid an atomic op if possible */
329         if (test_bit(PG_arch_1, &page->flags))
330                 clear_bit(PG_arch_1, &page->flags);
331 }
332 EXPORT_SYMBOL(flush_dcache_page);
333
334 void flush_dcache_icache_page(struct page *page)
335 {
336 #ifdef CONFIG_BOOKE
337         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
338         __flush_dcache_icache(start);
339         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
340 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
341         /* On 8xx there is no need to kmap since highmem is not supported */
342         __flush_dcache_icache(page_address(page)); 
343 #else
344         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
345 #endif
346
347 }
348 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
349 {
350         clear_page(page);
351
352         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
353                 return;
354         /*
355          * We shouldnt have to do this, but some versions of glibc
356          * require it (ld.so assumes zero filled pages are icache clean)
357          * - Anton
358          */
359
360         /* avoid an atomic op if possible */
361         if (test_bit(PG_arch_1, &pg->flags))
362                 clear_bit(PG_arch_1, &pg->flags);
363 }
364 EXPORT_SYMBOL(clear_user_page);
365
366 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
367                     struct page *pg)
368 {
369         copy_page(vto, vfrom);
370
371         /*
372          * We should be able to use the following optimisation, however
373          * there are two problems.
374          * Firstly a bug in some versions of binutils meant PLT sections
375          * were not marked executable.
376          * Secondly the first word in the GOT section is blrl, used
377          * to establish the GOT address. Until recently the GOT was
378          * not marked executable.
379          * - Anton
380          */
381 #if 0
382         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
383                 return;
384 #endif
385
386         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
387                 return;
388
389         /* avoid an atomic op if possible */
390         if (test_bit(PG_arch_1, &pg->flags))
391                 clear_bit(PG_arch_1, &pg->flags);
392 }
393
394 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
395                              unsigned long addr, int len)
396 {
397         unsigned long maddr;
398
399         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
400         flush_icache_range(maddr, maddr + len);
401         kunmap(page);
402 }
403 EXPORT_SYMBOL(flush_icache_user_range);
404
405 /*
406  * This is called at the end of handling a user page fault, when the
407  * fault has been handled by updating a PTE in the linux page tables.
408  * We use it to preload an HPTE into the hash table corresponding to
409  * the updated linux PTE.
410  * 
411  * This must always be called with the mm->page_table_lock held
412  */
413 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
414                       pte_t pte)
415 {
416         /* handle i-cache coherency */
417         unsigned long pfn = pte_pfn(pte);
418 #ifdef CONFIG_PPC32
419         pmd_t *pmd;
420 #else
421         unsigned long vsid;
422         void *pgdir;
423         pte_t *ptep;
424         int local = 0;
425         cpumask_t tmp;
426         unsigned long flags;
427 #endif
428
429         /* handle i-cache coherency */
430         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
431             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
432             pfn_valid(pfn)) {
433                 struct page *page = pfn_to_page(pfn);
434                 if (!PageReserved(page)
435                     && !test_bit(PG_arch_1, &page->flags)) {
436                         if (vma->vm_mm == current->active_mm) {
437 #ifdef CONFIG_8xx
438                         /* On 8xx, cache control instructions (particularly 
439                          * "dcbst" from flush_dcache_icache) fault as write 
440                          * operation if there is an unpopulated TLB entry 
441                          * for the address in question. To workaround that, 
442                          * we invalidate the TLB here, thus avoiding dcbst 
443                          * misbehaviour.
444                          */
445                                 _tlbie(address);
446 #endif
447                                 __flush_dcache_icache((void *) address);
448                         } else
449                                 flush_dcache_icache_page(page);
450                         set_bit(PG_arch_1, &page->flags);
451                 }
452         }
453
454 #ifdef CONFIG_PPC_STD_MMU
455         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
456         if (!pte_young(pte) || address >= TASK_SIZE)
457                 return;
458 #ifdef CONFIG_PPC32
459         if (Hash == 0)
460                 return;
461         pmd = pmd_offset(pgd_offset(vma->vm_mm, address), address);
462         if (!pmd_none(*pmd))
463                 add_hash_page(vma->vm_mm->context, address, pmd_val(*pmd));
464 #else
465         pgdir = vma->vm_mm->pgd;
466         if (pgdir == NULL)
467                 return;
468
469         ptep = find_linux_pte(pgdir, address);
470         if (!ptep)
471                 return;
472
473         vsid = get_vsid(vma->vm_mm->context.id, address);
474
475         local_irq_save(flags);
476         tmp = cpumask_of_cpu(smp_processor_id());
477         if (cpus_equal(vma->vm_mm->cpu_vm_mask, tmp))
478                 local = 1;
479
480         __hash_page(address, 0, vsid, ptep, 0x300, local);
481         local_irq_restore(flags);
482 #endif
483 #endif
484 }