resources: introduce generic page_is_ram()
[linux-3.10.git] / arch / mips / mm / init.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 - 2000 Ralf Baechle
7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
9  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
10  */
11 #include <linux/bug.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/signal.h>
15 #include <linux/sched.h>
16 #include <linux/smp.h>
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/types.h>
21 #include <linux/pagemap.h>
22 #include <linux/ptrace.h>
23 #include <linux/mman.h>
24 #include <linux/mm.h>
25 #include <linux/bootmem.h>
26 #include <linux/highmem.h>
27 #include <linux/swap.h>
28 #include <linux/proc_fs.h>
29 #include <linux/pfn.h>
30
31 #include <asm/asm-offsets.h>
32 #include <asm/bootinfo.h>
33 #include <asm/cachectl.h>
34 #include <asm/cpu.h>
35 #include <asm/dma.h>
36 #include <asm/kmap_types.h>
37 #include <asm/mmu_context.h>
38 #include <asm/sections.h>
39 #include <asm/pgtable.h>
40 #include <asm/pgalloc.h>
41 #include <asm/tlb.h>
42 #include <asm/fixmap.h>
43
44 /* Atomicity and interruptability */
45 #ifdef CONFIG_MIPS_MT_SMTC
46
47 #include <asm/mipsmtregs.h>
48
49 #define ENTER_CRITICAL(flags) \
50         { \
51         unsigned int mvpflags; \
52         local_irq_save(flags);\
53         mvpflags = dvpe()
54 #define EXIT_CRITICAL(flags) \
55         evpe(mvpflags); \
56         local_irq_restore(flags); \
57         }
58 #else
59
60 #define ENTER_CRITICAL(flags) local_irq_save(flags)
61 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
62
63 #endif /* CONFIG_MIPS_MT_SMTC */
64
65 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
66
67 /*
68  * We have up to 8 empty zeroed pages so we can map one of the right colour
69  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
70  * where we have to avoid VCED / VECI exceptions for good performance at
71  * any price.  Since page is never written to after the initialization we
72  * don't have to care about aliases on other CPUs.
73  */
74 unsigned long empty_zero_page, zero_page_mask;
75 EXPORT_SYMBOL_GPL(empty_zero_page);
76
77 /*
78  * Not static inline because used by IP27 special magic initialization code
79  */
80 unsigned long setup_zero_pages(void)
81 {
82         unsigned int order;
83         unsigned long size;
84         struct page *page;
85
86         if (cpu_has_vce)
87                 order = 3;
88         else
89                 order = 0;
90
91         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
92         if (!empty_zero_page)
93                 panic("Oh boy, that early out of memory?");
94
95         page = virt_to_page((void *)empty_zero_page);
96         split_page(page, order);
97         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
98                 SetPageReserved(page);
99                 page++;
100         }
101
102         size = PAGE_SIZE << order;
103         zero_page_mask = (size - 1) & PAGE_MASK;
104
105         return 1UL << order;
106 }
107
108 #ifdef CONFIG_MIPS_MT_SMTC
109 static pte_t *kmap_coherent_pte;
110 static void __init kmap_coherent_init(void)
111 {
112         unsigned long vaddr;
113
114         /* cache the first coherent kmap pte */
115         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
116         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
117 }
118 #else
119 static inline void kmap_coherent_init(void) {}
120 #endif
121
122 void *kmap_coherent(struct page *page, unsigned long addr)
123 {
124         enum fixed_addresses idx;
125         unsigned long vaddr, flags, entrylo;
126         unsigned long old_ctx;
127         pte_t pte;
128         int tlbidx;
129
130         BUG_ON(Page_dcache_dirty(page));
131
132         inc_preempt_count();
133         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
134 #ifdef CONFIG_MIPS_MT_SMTC
135         idx += FIX_N_COLOURS * smp_processor_id();
136 #endif
137         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
138         pte = mk_pte(page, PAGE_KERNEL);
139 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
140         entrylo = pte.pte_high;
141 #else
142         entrylo = pte_val(pte) >> 6;
143 #endif
144
145         ENTER_CRITICAL(flags);
146         old_ctx = read_c0_entryhi();
147         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
148         write_c0_entrylo0(entrylo);
149         write_c0_entrylo1(entrylo);
150 #ifdef CONFIG_MIPS_MT_SMTC
151         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
152         /* preload TLB instead of local_flush_tlb_one() */
153         mtc0_tlbw_hazard();
154         tlb_probe();
155         tlb_probe_hazard();
156         tlbidx = read_c0_index();
157         mtc0_tlbw_hazard();
158         if (tlbidx < 0)
159                 tlb_write_random();
160         else
161                 tlb_write_indexed();
162 #else
163         tlbidx = read_c0_wired();
164         write_c0_wired(tlbidx + 1);
165         write_c0_index(tlbidx);
166         mtc0_tlbw_hazard();
167         tlb_write_indexed();
168 #endif
169         tlbw_use_hazard();
170         write_c0_entryhi(old_ctx);
171         EXIT_CRITICAL(flags);
172
173         return (void*) vaddr;
174 }
175
176 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
177
178 void kunmap_coherent(void)
179 {
180 #ifndef CONFIG_MIPS_MT_SMTC
181         unsigned int wired;
182         unsigned long flags, old_ctx;
183
184         ENTER_CRITICAL(flags);
185         old_ctx = read_c0_entryhi();
186         wired = read_c0_wired() - 1;
187         write_c0_wired(wired);
188         write_c0_index(wired);
189         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
190         write_c0_entrylo0(0);
191         write_c0_entrylo1(0);
192         mtc0_tlbw_hazard();
193         tlb_write_indexed();
194         tlbw_use_hazard();
195         write_c0_entryhi(old_ctx);
196         EXIT_CRITICAL(flags);
197 #endif
198         dec_preempt_count();
199         preempt_check_resched();
200 }
201
202 void copy_user_highpage(struct page *to, struct page *from,
203         unsigned long vaddr, struct vm_area_struct *vma)
204 {
205         void *vfrom, *vto;
206
207         vto = kmap_atomic(to, KM_USER1);
208         if (cpu_has_dc_aliases &&
209             page_mapped(from) && !Page_dcache_dirty(from)) {
210                 vfrom = kmap_coherent(from, vaddr);
211                 copy_page(vto, vfrom);
212                 kunmap_coherent();
213         } else {
214                 vfrom = kmap_atomic(from, KM_USER0);
215                 copy_page(vto, vfrom);
216                 kunmap_atomic(vfrom, KM_USER0);
217         }
218         if ((!cpu_has_ic_fills_f_dc) ||
219             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
220                 flush_data_cache_page((unsigned long)vto);
221         kunmap_atomic(vto, KM_USER1);
222         /* Make sure this page is cleared on other CPU's too before using it */
223         smp_wmb();
224 }
225
226 void copy_to_user_page(struct vm_area_struct *vma,
227         struct page *page, unsigned long vaddr, void *dst, const void *src,
228         unsigned long len)
229 {
230         if (cpu_has_dc_aliases &&
231             page_mapped(page) && !Page_dcache_dirty(page)) {
232                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
233                 memcpy(vto, src, len);
234                 kunmap_coherent();
235         } else {
236                 memcpy(dst, src, len);
237                 if (cpu_has_dc_aliases)
238                         SetPageDcacheDirty(page);
239         }
240         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
241                 flush_cache_page(vma, vaddr, page_to_pfn(page));
242 }
243
244 void copy_from_user_page(struct vm_area_struct *vma,
245         struct page *page, unsigned long vaddr, void *dst, const void *src,
246         unsigned long len)
247 {
248         if (cpu_has_dc_aliases &&
249             page_mapped(page) && !Page_dcache_dirty(page)) {
250                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
251                 memcpy(dst, vfrom, len);
252                 kunmap_coherent();
253         } else {
254                 memcpy(dst, src, len);
255                 if (cpu_has_dc_aliases)
256                         SetPageDcacheDirty(page);
257         }
258 }
259
260 void __init fixrange_init(unsigned long start, unsigned long end,
261         pgd_t *pgd_base)
262 {
263 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
264         pgd_t *pgd;
265         pud_t *pud;
266         pmd_t *pmd;
267         pte_t *pte;
268         int i, j, k;
269         unsigned long vaddr;
270
271         vaddr = start;
272         i = __pgd_offset(vaddr);
273         j = __pud_offset(vaddr);
274         k = __pmd_offset(vaddr);
275         pgd = pgd_base + i;
276
277         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
278                 pud = (pud_t *)pgd;
279                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
280                         pmd = (pmd_t *)pud;
281                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
282                                 if (pmd_none(*pmd)) {
283                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
284                                         set_pmd(pmd, __pmd((unsigned long)pte));
285                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
286                                 }
287                                 vaddr += PMD_SIZE;
288                         }
289                         k = 0;
290                 }
291                 j = 0;
292         }
293 #endif
294 }
295
296 #ifndef CONFIG_NEED_MULTIPLE_NODES
297 int page_is_ram(unsigned long pagenr)
298 {
299         int i;
300
301         for (i = 0; i < boot_mem_map.nr_map; i++) {
302                 unsigned long addr, end;
303
304                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
305                         /* not usable memory */
306                         continue;
307
308                 addr = PFN_UP(boot_mem_map.map[i].addr);
309                 end = PFN_DOWN(boot_mem_map.map[i].addr +
310                                boot_mem_map.map[i].size);
311
312                 if (pagenr >= addr && pagenr < end)
313                         return 1;
314         }
315
316         return 0;
317 }
318
319 void __init paging_init(void)
320 {
321         unsigned long max_zone_pfns[MAX_NR_ZONES];
322         unsigned long lastpfn;
323
324         pagetable_init();
325
326 #ifdef CONFIG_HIGHMEM
327         kmap_init();
328 #endif
329         kmap_coherent_init();
330
331 #ifdef CONFIG_ZONE_DMA
332         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
333 #endif
334 #ifdef CONFIG_ZONE_DMA32
335         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
336 #endif
337         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
338         lastpfn = max_low_pfn;
339 #ifdef CONFIG_HIGHMEM
340         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
341         lastpfn = highend_pfn;
342
343         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
344                 printk(KERN_WARNING "This processor doesn't support highmem."
345                        " %ldk highmem ignored\n",
346                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
347                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
348                 lastpfn = max_low_pfn;
349         }
350 #endif
351
352         free_area_init_nodes(max_zone_pfns);
353 }
354
355 #ifdef CONFIG_64BIT
356 static struct kcore_list kcore_kseg0;
357 #endif
358
359 void __init mem_init(void)
360 {
361         unsigned long codesize, reservedpages, datasize, initsize;
362         unsigned long tmp, ram;
363
364 #ifdef CONFIG_HIGHMEM
365 #ifdef CONFIG_DISCONTIGMEM
366 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
367 #endif
368         max_mapnr = highend_pfn;
369 #else
370         max_mapnr = max_low_pfn;
371 #endif
372         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
373
374         totalram_pages += free_all_bootmem();
375         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
376
377         reservedpages = ram = 0;
378         for (tmp = 0; tmp < max_low_pfn; tmp++)
379                 if (page_is_ram(tmp)) {
380                         ram++;
381                         if (PageReserved(pfn_to_page(tmp)))
382                                 reservedpages++;
383                 }
384         num_physpages = ram;
385
386 #ifdef CONFIG_HIGHMEM
387         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
388                 struct page *page = pfn_to_page(tmp);
389
390                 if (!page_is_ram(tmp)) {
391                         SetPageReserved(page);
392                         continue;
393                 }
394                 ClearPageReserved(page);
395                 init_page_count(page);
396                 __free_page(page);
397                 totalhigh_pages++;
398         }
399         totalram_pages += totalhigh_pages;
400         num_physpages += totalhigh_pages;
401 #endif
402
403         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
404         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
405         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
406
407 #ifdef CONFIG_64BIT
408         if ((unsigned long) &_text > (unsigned long) CKSEG0)
409                 /* The -4 is a hack so that user tools don't have to handle
410                    the overflow.  */
411                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
412                                 0x80000000 - 4, KCORE_TEXT);
413 #endif
414
415         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
416                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
417                nr_free_pages() << (PAGE_SHIFT-10),
418                ram << (PAGE_SHIFT-10),
419                codesize >> 10,
420                reservedpages << (PAGE_SHIFT-10),
421                datasize >> 10,
422                initsize >> 10,
423                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
424 }
425 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
426
427 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
428 {
429         unsigned long pfn;
430
431         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
432                 struct page *page = pfn_to_page(pfn);
433                 void *addr = phys_to_virt(PFN_PHYS(pfn));
434
435                 ClearPageReserved(page);
436                 init_page_count(page);
437                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
438                 __free_page(page);
439                 totalram_pages++;
440         }
441         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
442 }
443
444 #ifdef CONFIG_BLK_DEV_INITRD
445 void free_initrd_mem(unsigned long start, unsigned long end)
446 {
447         free_init_pages("initrd memory",
448                         virt_to_phys((void *)start),
449                         virt_to_phys((void *)end));
450 }
451 #endif
452
453 void __init_refok free_initmem(void)
454 {
455         prom_free_prom_memory();
456         free_init_pages("unused kernel memory",
457                         __pa_symbol(&__init_begin),
458                         __pa_symbol(&__init_end));
459 }
460
461 unsigned long pgd_current[NR_CPUS];
462 /*
463  * On 64-bit we've got three-level pagetables with a slightly
464  * different layout ...
465  */
466 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
467
468 /*
469  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
470  * are constants.  So we use the variants from asm-offset.h until that gcc
471  * will officially be retired.
472  */
473 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
474 #ifdef CONFIG_64BIT
475 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
476 #endif
477 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);