xref: /openbmc/linux/arch/powerpc/mm/mem.c (revision 545e4006)
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/sparsemem.h>
48 #include <asm/vdso.h>
49 #include <asm/fixmap.h>
50 
51 #include "mmu_decl.h"
52 
53 #ifndef CPU_FTR_COHERENT_ICACHE
54 #define CPU_FTR_COHERENT_ICACHE	0	/* XXX for now */
55 #define CPU_FTR_NOEXECUTE	0
56 #endif
57 
58 int init_bootmem_done;
59 int mem_init_done;
60 unsigned long memory_limit;
61 
62 #ifdef CONFIG_HIGHMEM
63 pte_t *kmap_pte;
64 pgprot_t kmap_prot;
65 
66 EXPORT_SYMBOL(kmap_prot);
67 EXPORT_SYMBOL(kmap_pte);
68 
69 static inline pte_t *virt_to_kpte(unsigned long vaddr)
70 {
71 	return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
72 			vaddr), vaddr), vaddr);
73 }
74 #endif
75 
76 int page_is_ram(unsigned long pfn)
77 {
78 	unsigned long paddr = (pfn << PAGE_SHIFT);
79 
80 #ifndef CONFIG_PPC64	/* XXX for now */
81 	return paddr < __pa(high_memory);
82 #else
83 	int i;
84 	for (i=0; i < lmb.memory.cnt; i++) {
85 		unsigned long base;
86 
87 		base = lmb.memory.region[i].base;
88 
89 		if ((paddr >= base) &&
90 			(paddr < (base + lmb.memory.region[i].size))) {
91 			return 1;
92 		}
93 	}
94 
95 	return 0;
96 #endif
97 }
98 
99 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
100 			      unsigned long size, pgprot_t vma_prot)
101 {
102 	if (ppc_md.phys_mem_access_prot)
103 		return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
104 
105 	if (!page_is_ram(pfn))
106 		vma_prot = __pgprot(pgprot_val(vma_prot)
107 				    | _PAGE_GUARDED | _PAGE_NO_CACHE);
108 	return vma_prot;
109 }
110 EXPORT_SYMBOL(phys_mem_access_prot);
111 
112 #ifdef CONFIG_MEMORY_HOTPLUG
113 
114 #ifdef CONFIG_NUMA
115 int memory_add_physaddr_to_nid(u64 start)
116 {
117 	return hot_add_scn_to_nid(start);
118 }
119 #endif
120 
121 int arch_add_memory(int nid, u64 start, u64 size)
122 {
123 	struct pglist_data *pgdata;
124 	struct zone *zone;
125 	unsigned long start_pfn = start >> PAGE_SHIFT;
126 	unsigned long nr_pages = size >> PAGE_SHIFT;
127 
128 	pgdata = NODE_DATA(nid);
129 
130 	start = (unsigned long)__va(start);
131 	create_section_mapping(start, start + size);
132 
133 	/* this should work for most non-highmem platforms */
134 	zone = pgdata->node_zones;
135 
136 	return __add_pages(zone, start_pfn, nr_pages);
137 }
138 
139 #ifdef CONFIG_MEMORY_HOTREMOVE
140 int remove_memory(u64 start, u64 size)
141 {
142 	unsigned long start_pfn, end_pfn;
143 	int ret;
144 
145 	start_pfn = start >> PAGE_SHIFT;
146 	end_pfn = start_pfn + (size >> PAGE_SHIFT);
147 	ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
148 	if (ret)
149 		goto out;
150 	/* Arch-specific calls go here - next patch */
151 out:
152 	return ret;
153 }
154 #endif /* CONFIG_MEMORY_HOTREMOVE */
155 #endif /* CONFIG_MEMORY_HOTPLUG */
156 
157 /*
158  * walk_memory_resource() needs to make sure there is no holes in a given
159  * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
160  * Instead it maintains it in lmb.memory structures.  Walk through the
161  * memory regions, find holes and callback for contiguous regions.
162  */
163 int
164 walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
165 			int (*func)(unsigned long, unsigned long, void *))
166 {
167 	struct lmb_property res;
168 	unsigned long pfn, len;
169 	u64 end;
170 	int ret = -1;
171 
172 	res.base = (u64) start_pfn << PAGE_SHIFT;
173 	res.size = (u64) nr_pages << PAGE_SHIFT;
174 
175 	end = res.base + res.size - 1;
176 	while ((res.base < end) && (lmb_find(&res) >= 0)) {
177 		pfn = (unsigned long)(res.base >> PAGE_SHIFT);
178 		len = (unsigned long)(res.size >> PAGE_SHIFT);
179 		ret = (*func)(pfn, len, arg);
180 		if (ret)
181 			break;
182 		res.base += (res.size + 1);
183 		res.size = (end - res.base + 1);
184 	}
185 	return ret;
186 }
187 EXPORT_SYMBOL_GPL(walk_memory_resource);
188 
189 void show_mem(void)
190 {
191 	unsigned long total = 0, reserved = 0;
192 	unsigned long shared = 0, cached = 0;
193 	unsigned long highmem = 0;
194 	struct page *page;
195 	pg_data_t *pgdat;
196 	unsigned long i;
197 
198 	printk("Mem-info:\n");
199 	show_free_areas();
200 	for_each_online_pgdat(pgdat) {
201 		unsigned long flags;
202 		pgdat_resize_lock(pgdat, &flags);
203 		for (i = 0; i < pgdat->node_spanned_pages; i++) {
204 			if (!pfn_valid(pgdat->node_start_pfn + i))
205 				continue;
206 			page = pgdat_page_nr(pgdat, i);
207 			total++;
208 			if (PageHighMem(page))
209 				highmem++;
210 			if (PageReserved(page))
211 				reserved++;
212 			else if (PageSwapCache(page))
213 				cached++;
214 			else if (page_count(page))
215 				shared += page_count(page) - 1;
216 		}
217 		pgdat_resize_unlock(pgdat, &flags);
218 	}
219 	printk("%ld pages of RAM\n", total);
220 #ifdef CONFIG_HIGHMEM
221 	printk("%ld pages of HIGHMEM\n", highmem);
222 #endif
223 	printk("%ld reserved pages\n", reserved);
224 	printk("%ld pages shared\n", shared);
225 	printk("%ld pages swap cached\n", cached);
226 }
227 
228 /*
229  * Initialize the bootmem system and give it all the memory we
230  * have available.  If we are using highmem, we only put the
231  * lowmem into the bootmem system.
232  */
233 #ifndef CONFIG_NEED_MULTIPLE_NODES
234 void __init do_init_bootmem(void)
235 {
236 	unsigned long i;
237 	unsigned long start, bootmap_pages;
238 	unsigned long total_pages;
239 	int boot_mapsize;
240 
241 	max_low_pfn = max_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
242 	total_pages = (lmb_end_of_DRAM() - memstart_addr) >> PAGE_SHIFT;
243 #ifdef CONFIG_HIGHMEM
244 	total_pages = total_lowmem >> PAGE_SHIFT;
245 	max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
246 #endif
247 
248 	/*
249 	 * Find an area to use for the bootmem bitmap.  Calculate the size of
250 	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
251 	 * Add 1 additional page in case the address isn't page-aligned.
252 	 */
253 	bootmap_pages = bootmem_bootmap_pages(total_pages);
254 
255 	start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
256 
257 	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
258 	boot_mapsize = init_bootmem_node(NODE_DATA(0), start >> PAGE_SHIFT, min_low_pfn, max_low_pfn);
259 
260 	/* Add active regions with valid PFNs */
261 	for (i = 0; i < lmb.memory.cnt; i++) {
262 		unsigned long start_pfn, end_pfn;
263 		start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
264 		end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
265 		add_active_range(0, start_pfn, end_pfn);
266 	}
267 
268 	/* Add all physical memory to the bootmem map, mark each area
269 	 * present.
270 	 */
271 #ifdef CONFIG_HIGHMEM
272 	free_bootmem_with_active_regions(0, lowmem_end_addr >> PAGE_SHIFT);
273 
274 	/* reserve the sections we're already using */
275 	for (i = 0; i < lmb.reserved.cnt; i++) {
276 		unsigned long addr = lmb.reserved.region[i].base +
277 				     lmb_size_bytes(&lmb.reserved, i) - 1;
278 		if (addr < lowmem_end_addr)
279 			reserve_bootmem(lmb.reserved.region[i].base,
280 					lmb_size_bytes(&lmb.reserved, i),
281 					BOOTMEM_DEFAULT);
282 		else if (lmb.reserved.region[i].base < lowmem_end_addr) {
283 			unsigned long adjusted_size = lowmem_end_addr -
284 				      lmb.reserved.region[i].base;
285 			reserve_bootmem(lmb.reserved.region[i].base,
286 					adjusted_size, BOOTMEM_DEFAULT);
287 		}
288 	}
289 #else
290 	free_bootmem_with_active_regions(0, max_pfn);
291 
292 	/* reserve the sections we're already using */
293 	for (i = 0; i < lmb.reserved.cnt; i++)
294 		reserve_bootmem(lmb.reserved.region[i].base,
295 				lmb_size_bytes(&lmb.reserved, i),
296 				BOOTMEM_DEFAULT);
297 
298 #endif
299 	/* XXX need to clip this if using highmem? */
300 	sparse_memory_present_with_active_regions(0);
301 
302 	init_bootmem_done = 1;
303 }
304 
305 /* mark pages that don't exist as nosave */
306 static int __init mark_nonram_nosave(void)
307 {
308 	unsigned long lmb_next_region_start_pfn,
309 		      lmb_region_max_pfn;
310 	int i;
311 
312 	for (i = 0; i < lmb.memory.cnt - 1; i++) {
313 		lmb_region_max_pfn =
314 			(lmb.memory.region[i].base >> PAGE_SHIFT) +
315 			(lmb.memory.region[i].size >> PAGE_SHIFT);
316 		lmb_next_region_start_pfn =
317 			lmb.memory.region[i+1].base >> PAGE_SHIFT;
318 
319 		if (lmb_region_max_pfn < lmb_next_region_start_pfn)
320 			register_nosave_region(lmb_region_max_pfn,
321 					       lmb_next_region_start_pfn);
322 	}
323 
324 	return 0;
325 }
326 
327 /*
328  * paging_init() sets up the page tables - in fact we've already done this.
329  */
330 void __init paging_init(void)
331 {
332 	unsigned long total_ram = lmb_phys_mem_size();
333 	phys_addr_t top_of_ram = lmb_end_of_DRAM();
334 	unsigned long max_zone_pfns[MAX_NR_ZONES];
335 
336 #ifdef CONFIG_PPC32
337 	unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
338 	unsigned long end = __fix_to_virt(FIX_HOLE);
339 
340 	for (; v < end; v += PAGE_SIZE)
341 		map_page(v, 0, 0); /* XXX gross */
342 #endif
343 
344 #ifdef CONFIG_HIGHMEM
345 	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
346 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
347 
348 	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
349 	kmap_prot = PAGE_KERNEL;
350 #endif /* CONFIG_HIGHMEM */
351 
352 	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%lx\n",
353 	       (u64)top_of_ram, total_ram);
354 	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
355 	       (long int)((top_of_ram - total_ram) >> 20));
356 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
357 #ifdef CONFIG_HIGHMEM
358 	max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;
359 	max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
360 #else
361 	max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
362 #endif
363 	free_area_init_nodes(max_zone_pfns);
364 
365 	mark_nonram_nosave();
366 }
367 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
368 
369 void __init mem_init(void)
370 {
371 #ifdef CONFIG_NEED_MULTIPLE_NODES
372 	int nid;
373 #endif
374 	pg_data_t *pgdat;
375 	unsigned long i;
376 	struct page *page;
377 	unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
378 
379 	num_physpages = lmb.memory.size >> PAGE_SHIFT;
380 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
381 
382 #ifdef CONFIG_NEED_MULTIPLE_NODES
383         for_each_online_node(nid) {
384 		if (NODE_DATA(nid)->node_spanned_pages != 0) {
385 			printk("freeing bootmem node %d\n", nid);
386 			totalram_pages +=
387 				free_all_bootmem_node(NODE_DATA(nid));
388 		}
389 	}
390 #else
391 	max_mapnr = max_pfn;
392 	totalram_pages += free_all_bootmem();
393 #endif
394 	for_each_online_pgdat(pgdat) {
395 		for (i = 0; i < pgdat->node_spanned_pages; i++) {
396 			if (!pfn_valid(pgdat->node_start_pfn + i))
397 				continue;
398 			page = pgdat_page_nr(pgdat, i);
399 			if (PageReserved(page))
400 				reservedpages++;
401 		}
402 	}
403 
404 	codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
405 	datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
406 	initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
407 	bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
408 
409 #ifdef CONFIG_HIGHMEM
410 	{
411 		unsigned long pfn, highmem_mapnr;
412 
413 		highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
414 		for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
415 			struct page *page = pfn_to_page(pfn);
416 			if (lmb_is_reserved(pfn << PAGE_SHIFT))
417 				continue;
418 			ClearPageReserved(page);
419 			init_page_count(page);
420 			__free_page(page);
421 			totalhigh_pages++;
422 			reservedpages--;
423 		}
424 		totalram_pages += totalhigh_pages;
425 		printk(KERN_DEBUG "High memory: %luk\n",
426 		       totalhigh_pages << (PAGE_SHIFT-10));
427 	}
428 #endif /* CONFIG_HIGHMEM */
429 
430 	printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
431 	       "%luk reserved, %luk data, %luk bss, %luk init)\n",
432 		(unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
433 		num_physpages << (PAGE_SHIFT-10),
434 		codesize >> 10,
435 		reservedpages << (PAGE_SHIFT-10),
436 		datasize >> 10,
437 		bsssize >> 10,
438 		initsize >> 10);
439 
440 	mem_init_done = 1;
441 }
442 
443 /*
444  * This is called when a page has been modified by the kernel.
445  * It just marks the page as not i-cache clean.  We do the i-cache
446  * flush later when the page is given to a user process, if necessary.
447  */
448 void flush_dcache_page(struct page *page)
449 {
450 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
451 		return;
452 	/* avoid an atomic op if possible */
453 	if (test_bit(PG_arch_1, &page->flags))
454 		clear_bit(PG_arch_1, &page->flags);
455 }
456 EXPORT_SYMBOL(flush_dcache_page);
457 
458 void flush_dcache_icache_page(struct page *page)
459 {
460 #ifdef CONFIG_BOOKE
461 	void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
462 	__flush_dcache_icache(start);
463 	kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
464 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
465 	/* On 8xx there is no need to kmap since highmem is not supported */
466 	__flush_dcache_icache(page_address(page));
467 #else
468 	__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
469 #endif
470 
471 }
472 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
473 {
474 	clear_page(page);
475 
476 	/*
477 	 * We shouldnt have to do this, but some versions of glibc
478 	 * require it (ld.so assumes zero filled pages are icache clean)
479 	 * - Anton
480 	 */
481 	flush_dcache_page(pg);
482 }
483 EXPORT_SYMBOL(clear_user_page);
484 
485 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
486 		    struct page *pg)
487 {
488 	copy_page(vto, vfrom);
489 
490 	/*
491 	 * We should be able to use the following optimisation, however
492 	 * there are two problems.
493 	 * Firstly a bug in some versions of binutils meant PLT sections
494 	 * were not marked executable.
495 	 * Secondly the first word in the GOT section is blrl, used
496 	 * to establish the GOT address. Until recently the GOT was
497 	 * not marked executable.
498 	 * - Anton
499 	 */
500 #if 0
501 	if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
502 		return;
503 #endif
504 
505 	flush_dcache_page(pg);
506 }
507 
508 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
509 			     unsigned long addr, int len)
510 {
511 	unsigned long maddr;
512 
513 	maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
514 	flush_icache_range(maddr, maddr + len);
515 	kunmap(page);
516 }
517 EXPORT_SYMBOL(flush_icache_user_range);
518 
519 /*
520  * This is called at the end of handling a user page fault, when the
521  * fault has been handled by updating a PTE in the linux page tables.
522  * We use it to preload an HPTE into the hash table corresponding to
523  * the updated linux PTE.
524  *
525  * This must always be called with the pte lock held.
526  */
527 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
528 		      pte_t pte)
529 {
530 #ifdef CONFIG_PPC_STD_MMU
531 	unsigned long access = 0, trap;
532 #endif
533 	unsigned long pfn = pte_pfn(pte);
534 
535 	/* handle i-cache coherency */
536 	if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
537 	    !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
538 	    pfn_valid(pfn)) {
539 		struct page *page = pfn_to_page(pfn);
540 #ifdef CONFIG_8xx
541 		/* On 8xx, cache control instructions (particularly
542 		 * "dcbst" from flush_dcache_icache) fault as write
543 		 * operation if there is an unpopulated TLB entry
544 		 * for the address in question. To workaround that,
545 		 * we invalidate the TLB here, thus avoiding dcbst
546 		 * misbehaviour.
547 		 */
548 		_tlbie(address, 0 /* 8xx doesn't care about PID */);
549 #endif
550 		/* The _PAGE_USER test should really be _PAGE_EXEC, but
551 		 * older glibc versions execute some code from no-exec
552 		 * pages, which for now we are supporting.  If exec-only
553 		 * pages are ever implemented, this will have to change.
554 		 */
555 		if (!PageReserved(page) && (pte_val(pte) & _PAGE_USER)
556 		    && !test_bit(PG_arch_1, &page->flags)) {
557 			if (vma->vm_mm == current->active_mm) {
558 				__flush_dcache_icache((void *) address);
559 			} else
560 				flush_dcache_icache_page(page);
561 			set_bit(PG_arch_1, &page->flags);
562 		}
563 	}
564 
565 #ifdef CONFIG_PPC_STD_MMU
566 	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
567 	if (!pte_young(pte) || address >= TASK_SIZE)
568 		return;
569 
570 	/* We try to figure out if we are coming from an instruction
571 	 * access fault and pass that down to __hash_page so we avoid
572 	 * double-faulting on execution of fresh text. We have to test
573 	 * for regs NULL since init will get here first thing at boot
574 	 *
575 	 * We also avoid filling the hash if not coming from a fault
576 	 */
577 	if (current->thread.regs == NULL)
578 		return;
579 	trap = TRAP(current->thread.regs);
580 	if (trap == 0x400)
581 		access |= _PAGE_EXEC;
582 	else if (trap != 0x300)
583 		return;
584 	hash_preload(vma->vm_mm, address, access, trap);
585 #endif /* CONFIG_PPC_STD_MMU */
586 }
587