xref: /openbmc/linux/arch/mips/mm/init.c (revision 03638e62) 
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/export.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/memblock.h>
26 #include <linux/highmem.h>
27 #include <linux/swap.h>
28 #include <linux/proc_fs.h>
29 #include <linux/pfn.h>
30 #include <linux/hardirq.h>
31 #include <linux/gfp.h>
32 #include <linux/kcore.h>
33 #include <linux/initrd.h>
34 
35 #include <asm/bootinfo.h>
36 #include <asm/cachectl.h>
37 #include <asm/cpu.h>
38 #include <asm/dma.h>
39 #include <asm/kmap_types.h>
40 #include <asm/maar.h>
41 #include <asm/mmu_context.h>
42 #include <asm/sections.h>
43 #include <asm/pgtable.h>
44 #include <asm/pgalloc.h>
45 #include <asm/tlb.h>
46 #include <asm/fixmap.h>
47 
48 /*
49  * We have up to 8 empty zeroed pages so we can map one of the right colour
50  * when needed.	 This is necessary only on R4000 / R4400 SC and MC versions
51  * where we have to avoid VCED / VECI exceptions for good performance at
52  * any price.  Since page is never written to after the initialization we
53  * don't have to care about aliases on other CPUs.
54  */
55 unsigned long empty_zero_page, zero_page_mask;
56 EXPORT_SYMBOL_GPL(empty_zero_page);
57 EXPORT_SYMBOL(zero_page_mask);
58 
59 /*
60  * Not static inline because used by IP27 special magic initialization code
61  */
62 void setup_zero_pages(void)
63 {
64 	unsigned int order, i;
65 	struct page *page;
66 
67 	if (cpu_has_vce)
68 		order = 3;
69 	else
70 		order = 0;
71 
72 	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
73 	if (!empty_zero_page)
74 		panic("Oh boy, that early out of memory?");
75 
76 	page = virt_to_page((void *)empty_zero_page);
77 	split_page(page, order);
78 	for (i = 0; i < (1 << order); i++, page++)
79 		mark_page_reserved(page);
80 
81 	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
82 }
83 
84 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
85 {
86 	enum fixed_addresses idx;
87 	unsigned int uninitialized_var(old_mmid);
88 	unsigned long vaddr, flags, entrylo;
89 	unsigned long old_ctx;
90 	pte_t pte;
91 	int tlbidx;
92 
93 	BUG_ON(Page_dcache_dirty(page));
94 
95 	preempt_disable();
96 	pagefault_disable();
97 	idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
98 	idx += in_interrupt() ? FIX_N_COLOURS : 0;
99 	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
100 	pte = mk_pte(page, prot);
101 #if defined(CONFIG_XPA)
102 	entrylo = pte_to_entrylo(pte.pte_high);
103 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
104 	entrylo = pte.pte_high;
105 #else
106 	entrylo = pte_to_entrylo(pte_val(pte));
107 #endif
108 
109 	local_irq_save(flags);
110 	old_ctx = read_c0_entryhi();
111 	write_c0_entryhi(vaddr & (PAGE_MASK << 1));
112 	write_c0_entrylo0(entrylo);
113 	write_c0_entrylo1(entrylo);
114 	if (cpu_has_mmid) {
115 		old_mmid = read_c0_memorymapid();
116 		write_c0_memorymapid(MMID_KERNEL_WIRED);
117 	}
118 #ifdef CONFIG_XPA
119 	if (cpu_has_xpa) {
120 		entrylo = (pte.pte_low & _PFNX_MASK);
121 		writex_c0_entrylo0(entrylo);
122 		writex_c0_entrylo1(entrylo);
123 	}
124 #endif
125 	tlbidx = num_wired_entries();
126 	write_c0_wired(tlbidx + 1);
127 	write_c0_index(tlbidx);
128 	mtc0_tlbw_hazard();
129 	tlb_write_indexed();
130 	tlbw_use_hazard();
131 	write_c0_entryhi(old_ctx);
132 	if (cpu_has_mmid)
133 		write_c0_memorymapid(old_mmid);
134 	local_irq_restore(flags);
135 
136 	return (void*) vaddr;
137 }
138 
139 void *kmap_coherent(struct page *page, unsigned long addr)
140 {
141 	return __kmap_pgprot(page, addr, PAGE_KERNEL);
142 }
143 
144 void *kmap_noncoherent(struct page *page, unsigned long addr)
145 {
146 	return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
147 }
148 
149 void kunmap_coherent(void)
150 {
151 	unsigned int wired;
152 	unsigned long flags, old_ctx;
153 
154 	local_irq_save(flags);
155 	old_ctx = read_c0_entryhi();
156 	wired = num_wired_entries() - 1;
157 	write_c0_wired(wired);
158 	write_c0_index(wired);
159 	write_c0_entryhi(UNIQUE_ENTRYHI(wired));
160 	write_c0_entrylo0(0);
161 	write_c0_entrylo1(0);
162 	mtc0_tlbw_hazard();
163 	tlb_write_indexed();
164 	tlbw_use_hazard();
165 	write_c0_entryhi(old_ctx);
166 	local_irq_restore(flags);
167 	pagefault_enable();
168 	preempt_enable();
169 }
170 
171 void copy_user_highpage(struct page *to, struct page *from,
172 	unsigned long vaddr, struct vm_area_struct *vma)
173 {
174 	void *vfrom, *vto;
175 
176 	vto = kmap_atomic(to);
177 	if (cpu_has_dc_aliases &&
178 	    page_mapcount(from) && !Page_dcache_dirty(from)) {
179 		vfrom = kmap_coherent(from, vaddr);
180 		copy_page(vto, vfrom);
181 		kunmap_coherent();
182 	} else {
183 		vfrom = kmap_atomic(from);
184 		copy_page(vto, vfrom);
185 		kunmap_atomic(vfrom);
186 	}
187 	if ((!cpu_has_ic_fills_f_dc) ||
188 	    pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
189 		flush_data_cache_page((unsigned long)vto);
190 	kunmap_atomic(vto);
191 	/* Make sure this page is cleared on other CPU's too before using it */
192 	smp_wmb();
193 }
194 
195 void copy_to_user_page(struct vm_area_struct *vma,
196 	struct page *page, unsigned long vaddr, void *dst, const void *src,
197 	unsigned long len)
198 {
199 	if (cpu_has_dc_aliases &&
200 	    page_mapcount(page) && !Page_dcache_dirty(page)) {
201 		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
202 		memcpy(vto, src, len);
203 		kunmap_coherent();
204 	} else {
205 		memcpy(dst, src, len);
206 		if (cpu_has_dc_aliases)
207 			SetPageDcacheDirty(page);
208 	}
209 	if (vma->vm_flags & VM_EXEC)
210 		flush_cache_page(vma, vaddr, page_to_pfn(page));
211 }
212 
213 void copy_from_user_page(struct vm_area_struct *vma,
214 	struct page *page, unsigned long vaddr, void *dst, const void *src,
215 	unsigned long len)
216 {
217 	if (cpu_has_dc_aliases &&
218 	    page_mapcount(page) && !Page_dcache_dirty(page)) {
219 		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
220 		memcpy(dst, vfrom, len);
221 		kunmap_coherent();
222 	} else {
223 		memcpy(dst, src, len);
224 		if (cpu_has_dc_aliases)
225 			SetPageDcacheDirty(page);
226 	}
227 }
228 EXPORT_SYMBOL_GPL(copy_from_user_page);
229 
230 void __init fixrange_init(unsigned long start, unsigned long end,
231 	pgd_t *pgd_base)
232 {
233 #ifdef CONFIG_HIGHMEM
234 	pgd_t *pgd;
235 	pud_t *pud;
236 	pmd_t *pmd;
237 	pte_t *pte;
238 	int i, j, k;
239 	unsigned long vaddr;
240 
241 	vaddr = start;
242 	i = __pgd_offset(vaddr);
243 	j = __pud_offset(vaddr);
244 	k = __pmd_offset(vaddr);
245 	pgd = pgd_base + i;
246 
247 	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
248 		pud = (pud_t *)pgd;
249 		for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
250 			pmd = (pmd_t *)pud;
251 			for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
252 				if (pmd_none(*pmd)) {
253 					pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
254 									   PAGE_SIZE);
255 					if (!pte)
256 						panic("%s: Failed to allocate %lu bytes align=%lx\n",
257 						      __func__, PAGE_SIZE,
258 						      PAGE_SIZE);
259 
260 					set_pmd(pmd, __pmd((unsigned long)pte));
261 					BUG_ON(pte != pte_offset_kernel(pmd, 0));
262 				}
263 				vaddr += PMD_SIZE;
264 			}
265 			k = 0;
266 		}
267 		j = 0;
268 	}
269 #endif
270 }
271 
272 unsigned __weak platform_maar_init(unsigned num_pairs)
273 {
274 	struct maar_config cfg[BOOT_MEM_MAP_MAX];
275 	unsigned i, num_configured, num_cfg = 0;
276 
277 	for (i = 0; i < boot_mem_map.nr_map; i++) {
278 		switch (boot_mem_map.map[i].type) {
279 		case BOOT_MEM_RAM:
280 		case BOOT_MEM_INIT_RAM:
281 			break;
282 		default:
283 			continue;
284 		}
285 
286 		/* Round lower up */
287 		cfg[num_cfg].lower = boot_mem_map.map[i].addr;
288 		cfg[num_cfg].lower = (cfg[num_cfg].lower + 0xffff) & ~0xffff;
289 
290 		/* Round upper down */
291 		cfg[num_cfg].upper = boot_mem_map.map[i].addr +
292 					boot_mem_map.map[i].size;
293 		cfg[num_cfg].upper = (cfg[num_cfg].upper & ~0xffff) - 1;
294 
295 		cfg[num_cfg].attrs = MIPS_MAAR_S;
296 		num_cfg++;
297 	}
298 
299 	num_configured = maar_config(cfg, num_cfg, num_pairs);
300 	if (num_configured < num_cfg)
301 		pr_warn("Not enough MAAR pairs (%u) for all bootmem regions (%u)\n",
302 			num_pairs, num_cfg);
303 
304 	return num_configured;
305 }
306 
307 void maar_init(void)
308 {
309 	unsigned num_maars, used, i;
310 	phys_addr_t lower, upper, attr;
311 	static struct {
312 		struct maar_config cfgs[3];
313 		unsigned used;
314 	} recorded = { { { 0 } }, 0 };
315 
316 	if (!cpu_has_maar)
317 		return;
318 
319 	/* Detect the number of MAARs */
320 	write_c0_maari(~0);
321 	back_to_back_c0_hazard();
322 	num_maars = read_c0_maari() + 1;
323 
324 	/* MAARs should be in pairs */
325 	WARN_ON(num_maars % 2);
326 
327 	/* Set MAARs using values we recorded already */
328 	if (recorded.used) {
329 		used = maar_config(recorded.cfgs, recorded.used, num_maars / 2);
330 		BUG_ON(used != recorded.used);
331 	} else {
332 		/* Configure the required MAARs */
333 		used = platform_maar_init(num_maars / 2);
334 	}
335 
336 	/* Disable any further MAARs */
337 	for (i = (used * 2); i < num_maars; i++) {
338 		write_c0_maari(i);
339 		back_to_back_c0_hazard();
340 		write_c0_maar(0);
341 		back_to_back_c0_hazard();
342 	}
343 
344 	if (recorded.used)
345 		return;
346 
347 	pr_info("MAAR configuration:\n");
348 	for (i = 0; i < num_maars; i += 2) {
349 		write_c0_maari(i);
350 		back_to_back_c0_hazard();
351 		upper = read_c0_maar();
352 
353 		write_c0_maari(i + 1);
354 		back_to_back_c0_hazard();
355 		lower = read_c0_maar();
356 
357 		attr = lower & upper;
358 		lower = (lower & MIPS_MAAR_ADDR) << 4;
359 		upper = ((upper & MIPS_MAAR_ADDR) << 4) | 0xffff;
360 
361 		pr_info("  [%d]: ", i / 2);
362 		if (!(attr & MIPS_MAAR_VL)) {
363 			pr_cont("disabled\n");
364 			continue;
365 		}
366 
367 		pr_cont("%pa-%pa", &lower, &upper);
368 
369 		if (attr & MIPS_MAAR_S)
370 			pr_cont(" speculate");
371 
372 		pr_cont("\n");
373 
374 		/* Record the setup for use on secondary CPUs */
375 		if (used <= ARRAY_SIZE(recorded.cfgs)) {
376 			recorded.cfgs[recorded.used].lower = lower;
377 			recorded.cfgs[recorded.used].upper = upper;
378 			recorded.cfgs[recorded.used].attrs = attr;
379 			recorded.used++;
380 		}
381 	}
382 }
383 
384 #ifndef CONFIG_NEED_MULTIPLE_NODES
385 int page_is_ram(unsigned long pagenr)
386 {
387 	int i;
388 
389 	for (i = 0; i < boot_mem_map.nr_map; i++) {
390 		unsigned long addr, end;
391 
392 		switch (boot_mem_map.map[i].type) {
393 		case BOOT_MEM_RAM:
394 		case BOOT_MEM_INIT_RAM:
395 			break;
396 		default:
397 			/* not usable memory */
398 			continue;
399 		}
400 
401 		addr = PFN_UP(boot_mem_map.map[i].addr);
402 		end = PFN_DOWN(boot_mem_map.map[i].addr +
403 			       boot_mem_map.map[i].size);
404 
405 		if (pagenr >= addr && pagenr < end)
406 			return 1;
407 	}
408 
409 	return 0;
410 }
411 
412 void __init paging_init(void)
413 {
414 	unsigned long max_zone_pfns[MAX_NR_ZONES];
415 
416 	pagetable_init();
417 
418 #ifdef CONFIG_HIGHMEM
419 	kmap_init();
420 #endif
421 #ifdef CONFIG_ZONE_DMA
422 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
423 #endif
424 #ifdef CONFIG_ZONE_DMA32
425 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
426 #endif
427 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
428 #ifdef CONFIG_HIGHMEM
429 	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
430 
431 	if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
432 		printk(KERN_WARNING "This processor doesn't support highmem."
433 		       " %ldk highmem ignored\n",
434 		       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
435 		max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
436 	}
437 #endif
438 
439 	free_area_init_nodes(max_zone_pfns);
440 }
441 
442 #ifdef CONFIG_64BIT
443 static struct kcore_list kcore_kseg0;
444 #endif
445 
446 static inline void mem_init_free_highmem(void)
447 {
448 #ifdef CONFIG_HIGHMEM
449 	unsigned long tmp;
450 
451 	if (cpu_has_dc_aliases)
452 		return;
453 
454 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
455 		struct page *page = pfn_to_page(tmp);
456 
457 		if (!page_is_ram(tmp))
458 			SetPageReserved(page);
459 		else
460 			free_highmem_page(page);
461 	}
462 #endif
463 }
464 
465 void __init mem_init(void)
466 {
467 #ifdef CONFIG_HIGHMEM
468 #ifdef CONFIG_DISCONTIGMEM
469 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
470 #endif
471 	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
472 #else
473 	max_mapnr = max_low_pfn;
474 #endif
475 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
476 
477 	maar_init();
478 	memblock_free_all();
479 	setup_zero_pages();	/* Setup zeroed pages.  */
480 	mem_init_free_highmem();
481 	mem_init_print_info(NULL);
482 
483 #ifdef CONFIG_64BIT
484 	if ((unsigned long) &_text > (unsigned long) CKSEG0)
485 		/* The -4 is a hack so that user tools don't have to handle
486 		   the overflow.  */
487 		kclist_add(&kcore_kseg0, (void *) CKSEG0,
488 				0x80000000 - 4, KCORE_TEXT);
489 #endif
490 }
491 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
492 
493 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
494 {
495 	unsigned long pfn;
496 
497 	for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
498 		struct page *page = pfn_to_page(pfn);
499 		void *addr = phys_to_virt(PFN_PHYS(pfn));
500 
501 		memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
502 		free_reserved_page(page);
503 	}
504 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
505 }
506 
507 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
508 
509 void __ref free_initmem(void)
510 {
511 	prom_free_prom_memory();
512 	/*
513 	 * Let the platform define a specific function to free the
514 	 * init section since EVA may have used any possible mapping
515 	 * between virtual and physical addresses.
516 	 */
517 	if (free_init_pages_eva)
518 		free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
519 	else
520 		free_initmem_default(POISON_FREE_INITMEM);
521 }
522 
523 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
524 unsigned long pgd_current[NR_CPUS];
525 #endif
526 
527 /*
528  * Align swapper_pg_dir in to 64K, allows its address to be loaded
529  * with a single LUI instruction in the TLB handlers.  If we used
530  * __aligned(64K), its size would get rounded up to the alignment
531  * size, and waste space.  So we place it in its own section and align
532  * it in the linker script.
533  */
534 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
535 #ifndef __PAGETABLE_PUD_FOLDED
536 pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
537 #endif
538 #ifndef __PAGETABLE_PMD_FOLDED
539 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
540 EXPORT_SYMBOL_GPL(invalid_pmd_table);
541 #endif
542 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
543 EXPORT_SYMBOL(invalid_pte_table);
544