xref: /openbmc/linux/arch/powerpc/mm/mem.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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 extern void hash_preload(struct mm_struct *mm, unsigned long ea,
65 			 unsigned long access, unsigned long trap);
66 
67 /*
68  * This is called by /dev/mem to know if a given address has to
69  * be mapped non-cacheable or not
70  */
71 int page_is_ram(unsigned long pfn)
72 {
73 	unsigned long paddr = (pfn << PAGE_SHIFT);
74 
75 #ifndef CONFIG_PPC64	/* XXX for now */
76 	return paddr < __pa(high_memory);
77 #else
78 	int i;
79 	for (i=0; i < lmb.memory.cnt; i++) {
80 		unsigned long base;
81 
82 		base = lmb.memory.region[i].base;
83 
84 		if ((paddr >= base) &&
85 			(paddr < (base + lmb.memory.region[i].size))) {
86 			return 1;
87 		}
88 	}
89 
90 	return 0;
91 #endif
92 }
93 EXPORT_SYMBOL(page_is_ram);
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(pgprot_val(vma_prot)
103 				    | _PAGE_GUARDED | _PAGE_NO_CACHE);
104 	return vma_prot;
105 }
106 EXPORT_SYMBOL(phys_mem_access_prot);
107 
108 #ifdef CONFIG_MEMORY_HOTPLUG
109 
110 void online_page(struct page *page)
111 {
112 	ClearPageReserved(page);
113 	free_cold_page(page);
114 	totalram_pages++;
115 	num_physpages++;
116 }
117 
118 /*
119  * This works only for the non-NUMA case.  Later, we'll need a lookup
120  * to convert from real physical addresses to nid, that doesn't use
121  * pfn_to_nid().
122  */
123 int __devinit add_memory(u64 start, u64 size)
124 {
125 	struct pglist_data *pgdata = NODE_DATA(0);
126 	struct zone *zone;
127 	unsigned long start_pfn = start >> PAGE_SHIFT;
128 	unsigned long nr_pages = size >> PAGE_SHIFT;
129 
130 	/* this should work for most non-highmem platforms */
131 	zone = pgdata->node_zones;
132 
133 	return __add_pages(zone, start_pfn, nr_pages);
134 
135 	return 0;
136 }
137 
138 /*
139  * First pass at this code will check to determine if the remove
140  * request is within the RMO.  Do not allow removal within the RMO.
141  */
142 int __devinit remove_memory(u64 start, u64 size)
143 {
144 	struct zone *zone;
145 	unsigned long start_pfn, end_pfn, nr_pages;
146 
147 	start_pfn = start >> PAGE_SHIFT;
148 	nr_pages = size >> PAGE_SHIFT;
149 	end_pfn = start_pfn + nr_pages;
150 
151 	printk("%s(): Attempting to remove memoy in range "
152 			"%lx to %lx\n", __func__, start, start+size);
153 	/*
154 	 * check for range within RMO
155 	 */
156 	zone = page_zone(pfn_to_page(start_pfn));
157 
158 	printk("%s(): memory will be removed from "
159 			"the %s zone\n", __func__, zone->name);
160 
161 	/*
162 	 * not handling removing memory ranges that
163 	 * overlap multiple zones yet
164 	 */
165 	if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
166 		goto overlap;
167 
168 	/* make sure it is NOT in RMO */
169 	if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
170 		printk("%s(): range to be removed must NOT be in RMO!\n",
171 			__func__);
172 		goto in_rmo;
173 	}
174 
175 	return __remove_pages(zone, start_pfn, nr_pages);
176 
177 overlap:
178 	printk("%s(): memory range to be removed overlaps "
179 		"multiple zones!!!\n", __func__);
180 in_rmo:
181 	return -1;
182 }
183 #endif /* CONFIG_MEMORY_HOTPLUG */
184 
185 void show_mem(void)
186 {
187 	unsigned long total = 0, reserved = 0;
188 	unsigned long shared = 0, cached = 0;
189 	unsigned long highmem = 0;
190 	struct page *page;
191 	pg_data_t *pgdat;
192 	unsigned long i;
193 
194 	printk("Mem-info:\n");
195 	show_free_areas();
196 	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
197 	for_each_pgdat(pgdat) {
198 		unsigned long flags;
199 		pgdat_resize_lock(pgdat, &flags);
200 		for (i = 0; i < pgdat->node_spanned_pages; i++) {
201 			page = pgdat_page_nr(pgdat, i);
202 			total++;
203 			if (PageHighMem(page))
204 				highmem++;
205 			if (PageReserved(page))
206 				reserved++;
207 			else if (PageSwapCache(page))
208 				cached++;
209 			else if (page_count(page))
210 				shared += page_count(page) - 1;
211 		}
212 		pgdat_resize_unlock(pgdat, &flags);
213 	}
214 	printk("%ld pages of RAM\n", total);
215 #ifdef CONFIG_HIGHMEM
216 	printk("%ld pages of HIGHMEM\n", highmem);
217 #endif
218 	printk("%ld reserved pages\n", reserved);
219 	printk("%ld pages shared\n", shared);
220 	printk("%ld pages swap cached\n", cached);
221 }
222 
223 /*
224  * Initialize the bootmem system and give it all the memory we
225  * have available.  If we are using highmem, we only put the
226  * lowmem into the bootmem system.
227  */
228 #ifndef CONFIG_NEED_MULTIPLE_NODES
229 void __init do_init_bootmem(void)
230 {
231 	unsigned long i;
232 	unsigned long start, bootmap_pages;
233 	unsigned long total_pages;
234 	int boot_mapsize;
235 
236 	max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
237 #ifdef CONFIG_HIGHMEM
238 	total_pages = total_lowmem >> PAGE_SHIFT;
239 #endif
240 
241 	/*
242 	 * Find an area to use for the bootmem bitmap.  Calculate the size of
243 	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
244 	 * Add 1 additional page in case the address isn't page-aligned.
245 	 */
246 	bootmap_pages = bootmem_bootmap_pages(total_pages);
247 
248 	start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
249 	BUG_ON(!start);
250 
251 	boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
252 
253 	/* Add all physical memory to the bootmem map, mark each area
254 	 * present.
255 	 */
256 	for (i = 0; i < lmb.memory.cnt; i++) {
257 		unsigned long base = lmb.memory.region[i].base;
258 		unsigned long size = lmb_size_bytes(&lmb.memory, i);
259 #ifdef CONFIG_HIGHMEM
260 		if (base >= total_lowmem)
261 			continue;
262 		if (base + size > total_lowmem)
263 			size = total_lowmem - base;
264 #endif
265 		free_bootmem(base, size);
266 	}
267 
268 	/* reserve the sections we're already using */
269 	for (i = 0; i < lmb.reserved.cnt; i++)
270 		reserve_bootmem(lmb.reserved.region[i].base,
271 				lmb_size_bytes(&lmb.reserved, i));
272 
273 	/* XXX need to clip this if using highmem? */
274 	for (i = 0; i < lmb.memory.cnt; i++)
275 		memory_present(0, lmb_start_pfn(&lmb.memory, i),
276 			       lmb_end_pfn(&lmb.memory, i));
277 	init_bootmem_done = 1;
278 }
279 
280 /*
281  * paging_init() sets up the page tables - in fact we've already done this.
282  */
283 void __init paging_init(void)
284 {
285 	unsigned long zones_size[MAX_NR_ZONES];
286 	unsigned long zholes_size[MAX_NR_ZONES];
287 	unsigned long total_ram = lmb_phys_mem_size();
288 	unsigned long top_of_ram = lmb_end_of_DRAM();
289 
290 #ifdef CONFIG_HIGHMEM
291 	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
292 	pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
293 			(PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
294 	map_page(KMAP_FIX_BEGIN, 0, 0);	/* XXX gross */
295 	kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
296 			(KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
297 	kmap_prot = PAGE_KERNEL;
298 #endif /* CONFIG_HIGHMEM */
299 
300 	printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
301 	       top_of_ram, total_ram);
302 	printk(KERN_INFO "Memory hole size: %ldMB\n",
303 	       (top_of_ram - total_ram) >> 20);
304 	/*
305 	 * All pages are DMA-able so we put them all in the DMA zone.
306 	 */
307 	memset(zones_size, 0, sizeof(zones_size));
308 	memset(zholes_size, 0, sizeof(zholes_size));
309 
310 	zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
311 	zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
312 
313 #ifdef CONFIG_HIGHMEM
314 	zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
315 	zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
316 	zholes_size[ZONE_HIGHMEM] = (top_of_ram - total_ram) >> PAGE_SHIFT;
317 #else
318 	zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
319 	zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
320 #endif /* CONFIG_HIGHMEM */
321 
322 	free_area_init_node(0, NODE_DATA(0), zones_size,
323 			    __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
324 }
325 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
326 
327 void __init mem_init(void)
328 {
329 #ifdef CONFIG_NEED_MULTIPLE_NODES
330 	int nid;
331 #endif
332 	pg_data_t *pgdat;
333 	unsigned long i;
334 	struct page *page;
335 	unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
336 
337 	num_physpages = max_pfn;	/* RAM is assumed contiguous */
338 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
339 
340 #ifdef CONFIG_NEED_MULTIPLE_NODES
341         for_each_online_node(nid) {
342 		if (NODE_DATA(nid)->node_spanned_pages != 0) {
343 			printk("freeing bootmem node %x\n", nid);
344 			totalram_pages +=
345 				free_all_bootmem_node(NODE_DATA(nid));
346 		}
347 	}
348 #else
349 	max_mapnr = num_physpages;
350 	totalram_pages += free_all_bootmem();
351 #endif
352 	for_each_pgdat(pgdat) {
353 		for (i = 0; i < pgdat->node_spanned_pages; i++) {
354 			page = pgdat_page_nr(pgdat, i);
355 			if (PageReserved(page))
356 				reservedpages++;
357 		}
358 	}
359 
360 	codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
361 	datasize = (unsigned long)&__init_begin - (unsigned long)&_sdata;
362 	initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
363 	bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
364 
365 #ifdef CONFIG_HIGHMEM
366 	{
367 		unsigned long pfn, highmem_mapnr;
368 
369 		highmem_mapnr = total_lowmem >> PAGE_SHIFT;
370 		for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
371 			struct page *page = pfn_to_page(pfn);
372 
373 			ClearPageReserved(page);
374 			set_page_count(page, 1);
375 			__free_page(page);
376 			totalhigh_pages++;
377 		}
378 		totalram_pages += totalhigh_pages;
379 		printk(KERN_INFO "High memory: %luk\n",
380 		       totalhigh_pages << (PAGE_SHIFT-10));
381 	}
382 #endif /* CONFIG_HIGHMEM */
383 
384 	printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
385 	       "%luk reserved, %luk data, %luk bss, %luk init)\n",
386 		(unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
387 		num_physpages << (PAGE_SHIFT-10),
388 		codesize >> 10,
389 		reservedpages << (PAGE_SHIFT-10),
390 		datasize >> 10,
391 		bsssize >> 10,
392 		initsize >> 10);
393 
394 	mem_init_done = 1;
395 
396 #ifdef CONFIG_PPC64
397 	/* Initialize the vDSO */
398 	vdso_init();
399 #endif
400 }
401 
402 /*
403  * This is called when a page has been modified by the kernel.
404  * It just marks the page as not i-cache clean.  We do the i-cache
405  * flush later when the page is given to a user process, if necessary.
406  */
407 void flush_dcache_page(struct page *page)
408 {
409 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
410 		return;
411 	/* avoid an atomic op if possible */
412 	if (test_bit(PG_arch_1, &page->flags))
413 		clear_bit(PG_arch_1, &page->flags);
414 }
415 EXPORT_SYMBOL(flush_dcache_page);
416 
417 void flush_dcache_icache_page(struct page *page)
418 {
419 #ifdef CONFIG_BOOKE
420 	void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
421 	__flush_dcache_icache(start);
422 	kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
423 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
424 	/* On 8xx there is no need to kmap since highmem is not supported */
425 	__flush_dcache_icache(page_address(page));
426 #else
427 	__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
428 #endif
429 
430 }
431 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
432 {
433 	clear_page(page);
434 
435 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
436 		return;
437 	/*
438 	 * We shouldnt have to do this, but some versions of glibc
439 	 * require it (ld.so assumes zero filled pages are icache clean)
440 	 * - Anton
441 	 */
442 
443 	/* avoid an atomic op if possible */
444 	if (test_bit(PG_arch_1, &pg->flags))
445 		clear_bit(PG_arch_1, &pg->flags);
446 }
447 EXPORT_SYMBOL(clear_user_page);
448 
449 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
450 		    struct page *pg)
451 {
452 	copy_page(vto, vfrom);
453 
454 	/*
455 	 * We should be able to use the following optimisation, however
456 	 * there are two problems.
457 	 * Firstly a bug in some versions of binutils meant PLT sections
458 	 * were not marked executable.
459 	 * Secondly the first word in the GOT section is blrl, used
460 	 * to establish the GOT address. Until recently the GOT was
461 	 * not marked executable.
462 	 * - Anton
463 	 */
464 #if 0
465 	if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
466 		return;
467 #endif
468 
469 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
470 		return;
471 
472 	/* avoid an atomic op if possible */
473 	if (test_bit(PG_arch_1, &pg->flags))
474 		clear_bit(PG_arch_1, &pg->flags);
475 }
476 
477 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
478 			     unsigned long addr, int len)
479 {
480 	unsigned long maddr;
481 
482 	maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
483 	flush_icache_range(maddr, maddr + len);
484 	kunmap(page);
485 }
486 EXPORT_SYMBOL(flush_icache_user_range);
487 
488 /*
489  * This is called at the end of handling a user page fault, when the
490  * fault has been handled by updating a PTE in the linux page tables.
491  * We use it to preload an HPTE into the hash table corresponding to
492  * the updated linux PTE.
493  *
494  * This must always be called with the mm->page_table_lock held
495  */
496 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
497 		      pte_t pte)
498 {
499 #ifdef CONFIG_PPC_STD_MMU
500 	unsigned long access = 0, trap;
501 #endif
502 	unsigned long pfn = pte_pfn(pte);
503 
504 	/* handle i-cache coherency */
505 	if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
506 	    !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
507 	    pfn_valid(pfn)) {
508 		struct page *page = pfn_to_page(pfn);
509 		if (!PageReserved(page)
510 		    && !test_bit(PG_arch_1, &page->flags)) {
511 			if (vma->vm_mm == current->active_mm) {
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);
521 #endif
522 				__flush_dcache_icache((void *) address);
523 			} else
524 				flush_dcache_icache_page(page);
525 			set_bit(PG_arch_1, &page->flags);
526 		}
527 	}
528 
529 #ifdef CONFIG_PPC_STD_MMU
530 	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
531 	if (!pte_young(pte) || address >= TASK_SIZE)
532 		return;
533 
534 	/* We try to figure out if we are coming from an instruction
535 	 * access fault and pass that down to __hash_page so we avoid
536 	 * double-faulting on execution of fresh text. We have to test
537 	 * for regs NULL since init will get here first thing at boot
538 	 *
539 	 * We also avoid filling the hash if not coming from a fault
540 	 */
541 	if (current->thread.regs == NULL)
542 		return;
543 	trap = TRAP(current->thread.regs);
544 	if (trap == 0x400)
545 		access |= _PAGE_EXEC;
546 	else if (trap != 0x300)
547 		return;
548 	hash_preload(vma->vm_mm, address, access, trap);
549 #endif /* CONFIG_PPC_STD_MMU */
550 }
551