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Linux/arch/powerpc/mm/mem.c

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  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/export.h>
 21 #include <linux/sched.h>
 22 #include <linux/kernel.h>
 23 #include <linux/errno.h>
 24 #include <linux/string.h>
 25 #include <linux/gfp.h>
 26 #include <linux/types.h>
 27 #include <linux/mm.h>
 28 #include <linux/stddef.h>
 29 #include <linux/init.h>
 30 #include <linux/bootmem.h>
 31 #include <linux/highmem.h>
 32 #include <linux/initrd.h>
 33 #include <linux/pagemap.h>
 34 #include <linux/suspend.h>
 35 #include <linux/memblock.h>
 36 #include <linux/hugetlb.h>
 37 #include <linux/slab.h>
 38 
 39 #include <asm/pgalloc.h>
 40 #include <asm/prom.h>
 41 #include <asm/io.h>
 42 #include <asm/mmu_context.h>
 43 #include <asm/pgtable.h>
 44 #include <asm/mmu.h>
 45 #include <asm/smp.h>
 46 #include <asm/machdep.h>
 47 #include <asm/btext.h>
 48 #include <asm/tlb.h>
 49 #include <asm/sections.h>
 50 #include <asm/sparsemem.h>
 51 #include <asm/vdso.h>
 52 #include <asm/fixmap.h>
 53 #include <asm/swiotlb.h>
 54 #include <asm/rtas.h>
 55 
 56 #include "mmu_decl.h"
 57 
 58 #ifndef CPU_FTR_COHERENT_ICACHE
 59 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
 60 #define CPU_FTR_NOEXECUTE       0
 61 #endif
 62 
 63 int init_bootmem_done;
 64 int mem_init_done;
 65 unsigned long long memory_limit;
 66 
 67 #ifdef CONFIG_HIGHMEM
 68 pte_t *kmap_pte;
 69 EXPORT_SYMBOL(kmap_pte);
 70 pgprot_t kmap_prot;
 71 EXPORT_SYMBOL(kmap_prot);
 72 
 73 static inline pte_t *virt_to_kpte(unsigned long vaddr)
 74 {
 75         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
 76                         vaddr), vaddr), vaddr);
 77 }
 78 #endif
 79 
 80 int page_is_ram(unsigned long pfn)
 81 {
 82 #ifndef CONFIG_PPC64    /* XXX for now */
 83         return pfn < max_pfn;
 84 #else
 85         unsigned long paddr = (pfn << PAGE_SHIFT);
 86         struct memblock_region *reg;
 87 
 88         for_each_memblock(memory, reg)
 89                 if (paddr >= reg->base && paddr < (reg->base + reg->size))
 90                         return 1;
 91         return 0;
 92 #endif
 93 }
 94 
 95 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 96                               unsigned long size, pgprot_t vma_prot)
 97 {
 98         if (ppc_md.phys_mem_access_prot)
 99                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
100 
101         if (!page_is_ram(pfn))
102                 vma_prot = pgprot_noncached(vma_prot);
103 
104         return vma_prot;
105 }
106 EXPORT_SYMBOL(phys_mem_access_prot);
107 
108 #ifdef CONFIG_MEMORY_HOTPLUG
109 
110 #ifdef CONFIG_NUMA
111 int memory_add_physaddr_to_nid(u64 start)
112 {
113         return hot_add_scn_to_nid(start);
114 }
115 #endif
116 
117 int arch_add_memory(int nid, u64 start, u64 size)
118 {
119         struct pglist_data *pgdata;
120         struct zone *zone;
121         unsigned long start_pfn = start >> PAGE_SHIFT;
122         unsigned long nr_pages = size >> PAGE_SHIFT;
123 
124         pgdata = NODE_DATA(nid);
125 
126         start = (unsigned long)__va(start);
127         if (create_section_mapping(start, start + size))
128                 return -EINVAL;
129 
130         /* this should work for most non-highmem platforms */
131         zone = pgdata->node_zones;
132 
133         return __add_pages(nid, zone, start_pfn, nr_pages);
134 }
135 
136 #ifdef CONFIG_MEMORY_HOTREMOVE
137 int arch_remove_memory(u64 start, u64 size)
138 {
139         unsigned long start_pfn = start >> PAGE_SHIFT;
140         unsigned long nr_pages = size >> PAGE_SHIFT;
141         struct zone *zone;
142 
143         zone = page_zone(pfn_to_page(start_pfn));
144         return __remove_pages(zone, start_pfn, nr_pages);
145 }
146 #endif
147 #endif /* CONFIG_MEMORY_HOTPLUG */
148 
149 /*
150  * walk_memory_resource() needs to make sure there is no holes in a given
151  * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
152  * Instead it maintains it in memblock.memory structures.  Walk through the
153  * memory regions, find holes and callback for contiguous regions.
154  */
155 int
156 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
157                 void *arg, int (*func)(unsigned long, unsigned long, void *))
158 {
159         struct memblock_region *reg;
160         unsigned long end_pfn = start_pfn + nr_pages;
161         unsigned long tstart, tend;
162         int ret = -1;
163 
164         for_each_memblock(memory, reg) {
165                 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
166                 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
167                 if (tstart >= tend)
168                         continue;
169                 ret = (*func)(tstart, tend - tstart, arg);
170                 if (ret)
171                         break;
172         }
173         return ret;
174 }
175 EXPORT_SYMBOL_GPL(walk_system_ram_range);
176 
177 /*
178  * Initialize the bootmem system and give it all the memory we
179  * have available.  If we are using highmem, we only put the
180  * lowmem into the bootmem system.
181  */
182 #ifndef CONFIG_NEED_MULTIPLE_NODES
183 void __init do_init_bootmem(void)
184 {
185         unsigned long start, bootmap_pages;
186         unsigned long total_pages;
187         struct memblock_region *reg;
188         int boot_mapsize;
189 
190         max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
191         total_pages = (memblock_end_of_DRAM() - memstart_addr) >> PAGE_SHIFT;
192 #ifdef CONFIG_HIGHMEM
193         total_pages = total_lowmem >> PAGE_SHIFT;
194         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
195 #endif
196 
197         /*
198          * Find an area to use for the bootmem bitmap.  Calculate the size of
199          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
200          * Add 1 additional page in case the address isn't page-aligned.
201          */
202         bootmap_pages = bootmem_bootmap_pages(total_pages);
203 
204         start = memblock_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
205 
206         min_low_pfn = MEMORY_START >> PAGE_SHIFT;
207         boot_mapsize = init_bootmem_node(NODE_DATA(0), start >> PAGE_SHIFT, min_low_pfn, max_low_pfn);
208 
209         /* Place all memblock_regions in the same node and merge contiguous
210          * memblock_regions
211          */
212         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
213 
214         /* Add all physical memory to the bootmem map, mark each area
215          * present.
216          */
217 #ifdef CONFIG_HIGHMEM
218         free_bootmem_with_active_regions(0, lowmem_end_addr >> PAGE_SHIFT);
219 
220         /* reserve the sections we're already using */
221         for_each_memblock(reserved, reg) {
222                 unsigned long top = reg->base + reg->size - 1;
223                 if (top < lowmem_end_addr)
224                         reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
225                 else if (reg->base < lowmem_end_addr) {
226                         unsigned long trunc_size = lowmem_end_addr - reg->base;
227                         reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT);
228                 }
229         }
230 #else
231         free_bootmem_with_active_regions(0, max_pfn);
232 
233         /* reserve the sections we're already using */
234         for_each_memblock(reserved, reg)
235                 reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
236 #endif
237         /* XXX need to clip this if using highmem? */
238         sparse_memory_present_with_active_regions(0);
239 
240         init_bootmem_done = 1;
241 }
242 
243 /* mark pages that don't exist as nosave */
244 static int __init mark_nonram_nosave(void)
245 {
246         struct memblock_region *reg, *prev = NULL;
247 
248         for_each_memblock(memory, reg) {
249                 if (prev &&
250                     memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
251                         register_nosave_region(memblock_region_memory_end_pfn(prev),
252                                                memblock_region_memory_base_pfn(reg));
253                 prev = reg;
254         }
255         return 0;
256 }
257 
258 /*
259  * paging_init() sets up the page tables - in fact we've already done this.
260  */
261 void __init paging_init(void)
262 {
263         unsigned long long total_ram = memblock_phys_mem_size();
264         phys_addr_t top_of_ram = memblock_end_of_DRAM();
265         unsigned long max_zone_pfns[MAX_NR_ZONES];
266 
267 #ifdef CONFIG_PPC32
268         unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
269         unsigned long end = __fix_to_virt(FIX_HOLE);
270 
271         for (; v < end; v += PAGE_SIZE)
272                 map_page(v, 0, 0); /* XXX gross */
273 #endif
274 
275 #ifdef CONFIG_HIGHMEM
276         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
277         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
278 
279         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
280         kmap_prot = PAGE_KERNEL;
281 #endif /* CONFIG_HIGHMEM */
282 
283         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
284                (unsigned long long)top_of_ram, total_ram);
285         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
286                (long int)((top_of_ram - total_ram) >> 20));
287         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
288 #ifdef CONFIG_HIGHMEM
289         max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;
290         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
291 #else
292         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
293 #endif
294         free_area_init_nodes(max_zone_pfns);
295 
296         mark_nonram_nosave();
297 }
298 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
299 
300 void __init mem_init(void)
301 {
302 #ifdef CONFIG_NEED_MULTIPLE_NODES
303         int nid;
304 #endif
305         pg_data_t *pgdat;
306         unsigned long i;
307         struct page *page;
308         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
309 
310 #ifdef CONFIG_SWIOTLB
311         swiotlb_init(0);
312 #endif
313 
314         num_physpages = memblock_phys_mem_size() >> PAGE_SHIFT;
315         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
316 
317 #ifdef CONFIG_NEED_MULTIPLE_NODES
318         for_each_online_node(nid) {
319                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
320                         printk("freeing bootmem node %d\n", nid);
321                         totalram_pages +=
322                                 free_all_bootmem_node(NODE_DATA(nid));
323                 }
324         }
325 #else
326         max_mapnr = max_pfn;
327         totalram_pages += free_all_bootmem();
328 #endif
329         for_each_online_pgdat(pgdat) {
330                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
331                         if (!pfn_valid(pgdat->node_start_pfn + i))
332                                 continue;
333                         page = pgdat_page_nr(pgdat, i);
334                         if (PageReserved(page))
335                                 reservedpages++;
336                 }
337         }
338 
339         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
340         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
341         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
342         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
343 
344 #ifdef CONFIG_HIGHMEM
345         {
346                 unsigned long pfn, highmem_mapnr;
347 
348                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
349                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
350                         phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
351                         struct page *page = pfn_to_page(pfn);
352                         if (memblock_is_reserved(paddr))
353                                 continue;
354                         free_highmem_page(page);
355                         reservedpages--;
356                 }
357                 printk(KERN_DEBUG "High memory: %luk\n",
358                        totalhigh_pages << (PAGE_SHIFT-10));
359         }
360 #endif /* CONFIG_HIGHMEM */
361 
362 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
363         /*
364          * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
365          * functions.... do it here for the non-smp case.
366          */
367         per_cpu(next_tlbcam_idx, smp_processor_id()) =
368                 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
369 #endif
370 
371         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
372                "%luk reserved, %luk data, %luk bss, %luk init)\n",
373                 nr_free_pages() << (PAGE_SHIFT-10),
374                 num_physpages << (PAGE_SHIFT-10),
375                 codesize >> 10,
376                 reservedpages << (PAGE_SHIFT-10),
377                 datasize >> 10,
378                 bsssize >> 10,
379                 initsize >> 10);
380 
381 #ifdef CONFIG_PPC32
382         pr_info("Kernel virtual memory layout:\n");
383         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
384 #ifdef CONFIG_HIGHMEM
385         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
386                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
387 #endif /* CONFIG_HIGHMEM */
388 #ifdef CONFIG_NOT_COHERENT_CACHE
389         pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
390                 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
391 #endif /* CONFIG_NOT_COHERENT_CACHE */
392         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
393                 ioremap_bot, IOREMAP_TOP);
394         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
395                 VMALLOC_START, VMALLOC_END);
396 #endif /* CONFIG_PPC32 */
397 
398         mem_init_done = 1;
399 }
400 
401 void free_initmem(void)
402 {
403         ppc_md.progress = ppc_printk_progress;
404         free_initmem_default(POISON_FREE_INITMEM);
405 }
406 
407 #ifdef CONFIG_BLK_DEV_INITRD
408 void __init free_initrd_mem(unsigned long start, unsigned long end)
409 {
410         free_reserved_area(start, end, 0, "initrd");
411 }
412 #endif
413 
414 /*
415  * This is called when a page has been modified by the kernel.
416  * It just marks the page as not i-cache clean.  We do the i-cache
417  * flush later when the page is given to a user process, if necessary.
418  */
419 void flush_dcache_page(struct page *page)
420 {
421         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
422                 return;
423         /* avoid an atomic op if possible */
424         if (test_bit(PG_arch_1, &page->flags))
425                 clear_bit(PG_arch_1, &page->flags);
426 }
427 EXPORT_SYMBOL(flush_dcache_page);
428 
429 void flush_dcache_icache_page(struct page *page)
430 {
431 #ifdef CONFIG_HUGETLB_PAGE
432         if (PageCompound(page)) {
433                 flush_dcache_icache_hugepage(page);
434                 return;
435         }
436 #endif
437 #ifdef CONFIG_BOOKE
438         {
439                 void *start = kmap_atomic(page);
440                 __flush_dcache_icache(start);
441                 kunmap_atomic(start);
442         }
443 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
444         /* On 8xx there is no need to kmap since highmem is not supported */
445         __flush_dcache_icache(page_address(page)); 
446 #else
447         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
448 #endif
449 }
450 EXPORT_SYMBOL(flush_dcache_icache_page);
451 
452 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
453 {
454         clear_page(page);
455 
456         /*
457          * We shouldn't have to do this, but some versions of glibc
458          * require it (ld.so assumes zero filled pages are icache clean)
459          * - Anton
460          */
461         flush_dcache_page(pg);
462 }
463 EXPORT_SYMBOL(clear_user_page);
464 
465 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
466                     struct page *pg)
467 {
468         copy_page(vto, vfrom);
469 
470         /*
471          * We should be able to use the following optimisation, however
472          * there are two problems.
473          * Firstly a bug in some versions of binutils meant PLT sections
474          * were not marked executable.
475          * Secondly the first word in the GOT section is blrl, used
476          * to establish the GOT address. Until recently the GOT was
477          * not marked executable.
478          * - Anton
479          */
480 #if 0
481         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
482                 return;
483 #endif
484 
485         flush_dcache_page(pg);
486 }
487 
488 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
489                              unsigned long addr, int len)
490 {
491         unsigned long maddr;
492 
493         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
494         flush_icache_range(maddr, maddr + len);
495         kunmap(page);
496 }
497 EXPORT_SYMBOL(flush_icache_user_range);
498 
499 /*
500  * This is called at the end of handling a user page fault, when the
501  * fault has been handled by updating a PTE in the linux page tables.
502  * We use it to preload an HPTE into the hash table corresponding to
503  * the updated linux PTE.
504  * 
505  * This must always be called with the pte lock held.
506  */
507 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
508                       pte_t *ptep)
509 {
510 #ifdef CONFIG_PPC_STD_MMU
511         unsigned long access = 0, trap;
512 
513         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
514         if (!pte_young(*ptep) || address >= TASK_SIZE)
515                 return;
516 
517         /* We try to figure out if we are coming from an instruction
518          * access fault and pass that down to __hash_page so we avoid
519          * double-faulting on execution of fresh text. We have to test
520          * for regs NULL since init will get here first thing at boot
521          *
522          * We also avoid filling the hash if not coming from a fault
523          */
524         if (current->thread.regs == NULL)
525                 return;
526         trap = TRAP(current->thread.regs);
527         if (trap == 0x400)
528                 access |= _PAGE_EXEC;
529         else if (trap != 0x300)
530                 return;
531         hash_preload(vma->vm_mm, address, access, trap);
532 #endif /* CONFIG_PPC_STD_MMU */
533 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
534         && defined(CONFIG_HUGETLB_PAGE)
535         if (is_vm_hugetlb_page(vma))
536                 book3e_hugetlb_preload(vma, address, *ptep);
537 #endif
538 }
539 
540 /*
541  * System memory should not be in /proc/iomem but various tools expect it
542  * (eg kdump).
543  */
544 static int add_system_ram_resources(void)
545 {
546         struct memblock_region *reg;
547 
548         for_each_memblock(memory, reg) {
549                 struct resource *res;
550                 unsigned long base = reg->base;
551                 unsigned long size = reg->size;
552 
553                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
554                 WARN_ON(!res);
555 
556                 if (res) {
557                         res->name = "System RAM";
558                         res->start = base;
559                         res->end = base + size - 1;
560                         res->flags = IORESOURCE_MEM;
561                         WARN_ON(request_resource(&iomem_resource, res) < 0);
562                 }
563         }
564 
565         return 0;
566 }
567 subsys_initcall(add_system_ram_resources);
568 
569 #ifdef CONFIG_STRICT_DEVMEM
570 /*
571  * devmem_is_allowed(): check to see if /dev/mem access to a certain address
572  * is valid. The argument is a physical page number.
573  *
574  * Access has to be given to non-kernel-ram areas as well, these contain the
575  * PCI mmio resources as well as potential bios/acpi data regions.
576  */
577 int devmem_is_allowed(unsigned long pfn)
578 {
579         if (iomem_is_exclusive(pfn << PAGE_SHIFT))
580                 return 0;
581         if (!page_is_ram(pfn))
582                 return 1;
583         if (page_is_rtas_user_buf(pfn))
584                 return 1;
585         return 0;
586 }
587 #endif /* CONFIG_STRICT_DEVMEM */
588 

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