xref: /openbmc/linux/arch/mips/mm/init.c (revision 9dbbc3b9) 
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/maar.h>
40 #include <asm/mmu_context.h>
41 #include <asm/sections.h>
42 #include <asm/pgalloc.h>
43 #include <asm/tlb.h>
44 #include <asm/fixmap.h>
45 
46 /*
47  * We have up to 8 empty zeroed pages so we can map one of the right colour
48  * when needed.	 This is necessary only on R4000 / R4400 SC and MC versions
49  * where we have to avoid VCED / VECI exceptions for good performance at
50  * any price.  Since page is never written to after the initialization we
51  * don't have to care about aliases on other CPUs.
52  */
53 unsigned long empty_zero_page, zero_page_mask;
54 EXPORT_SYMBOL_GPL(empty_zero_page);
55 EXPORT_SYMBOL(zero_page_mask);
56 
57 /*
58  * Not static inline because used by IP27 special magic initialization code
59  */
60 void setup_zero_pages(void)
61 {
62 	unsigned int order, i;
63 	struct page *page;
64 
65 	if (cpu_has_vce)
66 		order = 3;
67 	else
68 		order = 0;
69 
70 	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
71 	if (!empty_zero_page)
72 		panic("Oh boy, that early out of memory?");
73 
74 	page = virt_to_page((void *)empty_zero_page);
75 	split_page(page, order);
76 	for (i = 0; i < (1 << order); i++, page++)
77 		mark_page_reserved(page);
78 
79 	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
80 }
81 
82 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
83 {
84 	enum fixed_addresses idx;
85 	unsigned int old_mmid;
86 	unsigned long vaddr, flags, entrylo;
87 	unsigned long old_ctx;
88 	pte_t pte;
89 	int tlbidx;
90 
91 	BUG_ON(Page_dcache_dirty(page));
92 
93 	preempt_disable();
94 	pagefault_disable();
95 	idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
96 	idx += in_interrupt() ? FIX_N_COLOURS : 0;
97 	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
98 	pte = mk_pte(page, prot);
99 #if defined(CONFIG_XPA)
100 	entrylo = pte_to_entrylo(pte.pte_high);
101 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
102 	entrylo = pte.pte_high;
103 #else
104 	entrylo = pte_to_entrylo(pte_val(pte));
105 #endif
106 
107 	local_irq_save(flags);
108 	old_ctx = read_c0_entryhi();
109 	write_c0_entryhi(vaddr & (PAGE_MASK << 1));
110 	write_c0_entrylo0(entrylo);
111 	write_c0_entrylo1(entrylo);
112 	if (cpu_has_mmid) {
113 		old_mmid = read_c0_memorymapid();
114 		write_c0_memorymapid(MMID_KERNEL_WIRED);
115 	}
116 #ifdef CONFIG_XPA
117 	if (cpu_has_xpa) {
118 		entrylo = (pte.pte_low & _PFNX_MASK);
119 		writex_c0_entrylo0(entrylo);
120 		writex_c0_entrylo1(entrylo);
121 	}
122 #endif
123 	tlbidx = num_wired_entries();
124 	write_c0_wired(tlbidx + 1);
125 	write_c0_index(tlbidx);
126 	mtc0_tlbw_hazard();
127 	tlb_write_indexed();
128 	tlbw_use_hazard();
129 	write_c0_entryhi(old_ctx);
130 	if (cpu_has_mmid)
131 		write_c0_memorymapid(old_mmid);
132 	local_irq_restore(flags);
133 
134 	return (void*) vaddr;
135 }
136 
137 void *kmap_coherent(struct page *page, unsigned long addr)
138 {
139 	return __kmap_pgprot(page, addr, PAGE_KERNEL);
140 }
141 
142 void *kmap_noncoherent(struct page *page, unsigned long addr)
143 {
144 	return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
145 }
146 
147 void kunmap_coherent(void)
148 {
149 	unsigned int wired;
150 	unsigned long flags, old_ctx;
151 
152 	local_irq_save(flags);
153 	old_ctx = read_c0_entryhi();
154 	wired = num_wired_entries() - 1;
155 	write_c0_wired(wired);
156 	write_c0_index(wired);
157 	write_c0_entryhi(UNIQUE_ENTRYHI(wired));
158 	write_c0_entrylo0(0);
159 	write_c0_entrylo1(0);
160 	mtc0_tlbw_hazard();
161 	tlb_write_indexed();
162 	tlbw_use_hazard();
163 	write_c0_entryhi(old_ctx);
164 	local_irq_restore(flags);
165 	pagefault_enable();
166 	preempt_enable();
167 }
168 
169 void copy_user_highpage(struct page *to, struct page *from,
170 	unsigned long vaddr, struct vm_area_struct *vma)
171 {
172 	void *vfrom, *vto;
173 
174 	vto = kmap_atomic(to);
175 	if (cpu_has_dc_aliases &&
176 	    page_mapcount(from) && !Page_dcache_dirty(from)) {
177 		vfrom = kmap_coherent(from, vaddr);
178 		copy_page(vto, vfrom);
179 		kunmap_coherent();
180 	} else {
181 		vfrom = kmap_atomic(from);
182 		copy_page(vto, vfrom);
183 		kunmap_atomic(vfrom);
184 	}
185 	if ((!cpu_has_ic_fills_f_dc) ||
186 	    pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
187 		flush_data_cache_page((unsigned long)vto);
188 	kunmap_atomic(vto);
189 	/* Make sure this page is cleared on other CPU's too before using it */
190 	smp_wmb();
191 }
192 
193 void copy_to_user_page(struct vm_area_struct *vma,
194 	struct page *page, unsigned long vaddr, void *dst, const void *src,
195 	unsigned long len)
196 {
197 	if (cpu_has_dc_aliases &&
198 	    page_mapcount(page) && !Page_dcache_dirty(page)) {
199 		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
200 		memcpy(vto, src, len);
201 		kunmap_coherent();
202 	} else {
203 		memcpy(dst, src, len);
204 		if (cpu_has_dc_aliases)
205 			SetPageDcacheDirty(page);
206 	}
207 	if (vma->vm_flags & VM_EXEC)
208 		flush_cache_page(vma, vaddr, page_to_pfn(page));
209 }
210 
211 void copy_from_user_page(struct vm_area_struct *vma,
212 	struct page *page, unsigned long vaddr, void *dst, const void *src,
213 	unsigned long len)
214 {
215 	if (cpu_has_dc_aliases &&
216 	    page_mapcount(page) && !Page_dcache_dirty(page)) {
217 		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
218 		memcpy(dst, vfrom, len);
219 		kunmap_coherent();
220 	} else {
221 		memcpy(dst, src, len);
222 		if (cpu_has_dc_aliases)
223 			SetPageDcacheDirty(page);
224 	}
225 }
226 EXPORT_SYMBOL_GPL(copy_from_user_page);
227 
228 void __init fixrange_init(unsigned long start, unsigned long end,
229 	pgd_t *pgd_base)
230 {
231 #ifdef CONFIG_HIGHMEM
232 	pgd_t *pgd;
233 	pud_t *pud;
234 	pmd_t *pmd;
235 	pte_t *pte;
236 	int i, j, k;
237 	unsigned long vaddr;
238 
239 	vaddr = start;
240 	i = pgd_index(vaddr);
241 	j = pud_index(vaddr);
242 	k = pmd_index(vaddr);
243 	pgd = pgd_base + i;
244 
245 	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
246 		pud = (pud_t *)pgd;
247 		for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
248 			pmd = (pmd_t *)pud;
249 			for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
250 				if (pmd_none(*pmd)) {
251 					pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
252 									   PAGE_SIZE);
253 					if (!pte)
254 						panic("%s: Failed to allocate %lu bytes align=%lx\n",
255 						      __func__, PAGE_SIZE,
256 						      PAGE_SIZE);
257 
258 					set_pmd(pmd, __pmd((unsigned long)pte));
259 					BUG_ON(pte != pte_offset_kernel(pmd, 0));
260 				}
261 				vaddr += PMD_SIZE;
262 			}
263 			k = 0;
264 		}
265 		j = 0;
266 	}
267 #endif
268 }
269 
270 struct maar_walk_info {
271 	struct maar_config cfg[16];
272 	unsigned int num_cfg;
273 };
274 
275 static int maar_res_walk(unsigned long start_pfn, unsigned long nr_pages,
276 			 void *data)
277 {
278 	struct maar_walk_info *wi = data;
279 	struct maar_config *cfg = &wi->cfg[wi->num_cfg];
280 	unsigned int maar_align;
281 
282 	/* MAAR registers hold physical addresses right shifted by 4 bits */
283 	maar_align = BIT(MIPS_MAAR_ADDR_SHIFT + 4);
284 
285 	/* Fill in the MAAR config entry */
286 	cfg->lower = ALIGN(PFN_PHYS(start_pfn), maar_align);
287 	cfg->upper = ALIGN_DOWN(PFN_PHYS(start_pfn + nr_pages), maar_align) - 1;
288 	cfg->attrs = MIPS_MAAR_S;
289 
290 	/* Ensure we don't overflow the cfg array */
291 	if (!WARN_ON(wi->num_cfg >= ARRAY_SIZE(wi->cfg)))
292 		wi->num_cfg++;
293 
294 	return 0;
295 }
296 
297 
298 unsigned __weak platform_maar_init(unsigned num_pairs)
299 {
300 	unsigned int num_configured;
301 	struct maar_walk_info wi;
302 
303 	wi.num_cfg = 0;
304 	walk_system_ram_range(0, max_pfn, &wi, maar_res_walk);
305 
306 	num_configured = maar_config(wi.cfg, wi.num_cfg, num_pairs);
307 	if (num_configured < wi.num_cfg)
308 		pr_warn("Not enough MAAR pairs (%u) for all memory regions (%u)\n",
309 			num_pairs, wi.num_cfg);
310 
311 	return num_configured;
312 }
313 
314 void maar_init(void)
315 {
316 	unsigned num_maars, used, i;
317 	phys_addr_t lower, upper, attr;
318 	static struct {
319 		struct maar_config cfgs[3];
320 		unsigned used;
321 	} recorded = { { { 0 } }, 0 };
322 
323 	if (!cpu_has_maar)
324 		return;
325 
326 	/* Detect the number of MAARs */
327 	write_c0_maari(~0);
328 	back_to_back_c0_hazard();
329 	num_maars = read_c0_maari() + 1;
330 
331 	/* MAARs should be in pairs */
332 	WARN_ON(num_maars % 2);
333 
334 	/* Set MAARs using values we recorded already */
335 	if (recorded.used) {
336 		used = maar_config(recorded.cfgs, recorded.used, num_maars / 2);
337 		BUG_ON(used != recorded.used);
338 	} else {
339 		/* Configure the required MAARs */
340 		used = platform_maar_init(num_maars / 2);
341 	}
342 
343 	/* Disable any further MAARs */
344 	for (i = (used * 2); i < num_maars; i++) {
345 		write_c0_maari(i);
346 		back_to_back_c0_hazard();
347 		write_c0_maar(0);
348 		back_to_back_c0_hazard();
349 	}
350 
351 	if (recorded.used)
352 		return;
353 
354 	pr_info("MAAR configuration:\n");
355 	for (i = 0; i < num_maars; i += 2) {
356 		write_c0_maari(i);
357 		back_to_back_c0_hazard();
358 		upper = read_c0_maar();
359 #ifdef CONFIG_XPA
360 		upper |= (phys_addr_t)readx_c0_maar() << MIPS_MAARX_ADDR_SHIFT;
361 #endif
362 
363 		write_c0_maari(i + 1);
364 		back_to_back_c0_hazard();
365 		lower = read_c0_maar();
366 #ifdef CONFIG_XPA
367 		lower |= (phys_addr_t)readx_c0_maar() << MIPS_MAARX_ADDR_SHIFT;
368 #endif
369 
370 		attr = lower & upper;
371 		lower = (lower & MIPS_MAAR_ADDR) << 4;
372 		upper = ((upper & MIPS_MAAR_ADDR) << 4) | 0xffff;
373 
374 		pr_info("  [%d]: ", i / 2);
375 		if ((attr & MIPS_MAAR_V) != MIPS_MAAR_V) {
376 			pr_cont("disabled\n");
377 			continue;
378 		}
379 
380 		pr_cont("%pa-%pa", &lower, &upper);
381 
382 		if (attr & MIPS_MAAR_S)
383 			pr_cont(" speculate");
384 
385 		pr_cont("\n");
386 
387 		/* Record the setup for use on secondary CPUs */
388 		if (used <= ARRAY_SIZE(recorded.cfgs)) {
389 			recorded.cfgs[recorded.used].lower = lower;
390 			recorded.cfgs[recorded.used].upper = upper;
391 			recorded.cfgs[recorded.used].attrs = attr;
392 			recorded.used++;
393 		}
394 	}
395 }
396 
397 #ifndef CONFIG_NUMA
398 void __init paging_init(void)
399 {
400 	unsigned long max_zone_pfns[MAX_NR_ZONES];
401 
402 	pagetable_init();
403 
404 #ifdef CONFIG_ZONE_DMA
405 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
406 #endif
407 #ifdef CONFIG_ZONE_DMA32
408 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
409 #endif
410 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
411 #ifdef CONFIG_HIGHMEM
412 	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
413 
414 	if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
415 		printk(KERN_WARNING "This processor doesn't support highmem."
416 		       " %ldk highmem ignored\n",
417 		       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
418 		max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
419 	}
420 #endif
421 
422 	free_area_init(max_zone_pfns);
423 }
424 
425 #ifdef CONFIG_64BIT
426 static struct kcore_list kcore_kseg0;
427 #endif
428 
429 static inline void __init mem_init_free_highmem(void)
430 {
431 #ifdef CONFIG_HIGHMEM
432 	unsigned long tmp;
433 
434 	if (cpu_has_dc_aliases)
435 		return;
436 
437 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
438 		struct page *page = pfn_to_page(tmp);
439 
440 		if (!memblock_is_memory(PFN_PHYS(tmp)))
441 			SetPageReserved(page);
442 		else
443 			free_highmem_page(page);
444 	}
445 #endif
446 }
447 
448 void __init mem_init(void)
449 {
450 	/*
451 	 * When _PFN_SHIFT is greater than PAGE_SHIFT we won't have enough PTE
452 	 * bits to hold a full 32b physical address on MIPS32 systems.
453 	 */
454 	BUILD_BUG_ON(IS_ENABLED(CONFIG_32BIT) && (_PFN_SHIFT > PAGE_SHIFT));
455 
456 #ifdef CONFIG_HIGHMEM
457 	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
458 #else
459 	max_mapnr = max_low_pfn;
460 #endif
461 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
462 
463 	maar_init();
464 	memblock_free_all();
465 	setup_zero_pages();	/* Setup zeroed pages.  */
466 	mem_init_free_highmem();
467 
468 #ifdef CONFIG_64BIT
469 	if ((unsigned long) &_text > (unsigned long) CKSEG0)
470 		/* The -4 is a hack so that user tools don't have to handle
471 		   the overflow.  */
472 		kclist_add(&kcore_kseg0, (void *) CKSEG0,
473 				0x80000000 - 4, KCORE_TEXT);
474 #endif
475 }
476 #endif /* !CONFIG_NUMA */
477 
478 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
479 {
480 	unsigned long pfn;
481 
482 	for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
483 		struct page *page = pfn_to_page(pfn);
484 		void *addr = phys_to_virt(PFN_PHYS(pfn));
485 
486 		memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
487 		free_reserved_page(page);
488 	}
489 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
490 }
491 
492 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
493 
494 void __weak __init prom_free_prom_memory(void)
495 {
496 	/* nothing to do */
497 }
498 
499 void __ref free_initmem(void)
500 {
501 	prom_free_prom_memory();
502 	/*
503 	 * Let the platform define a specific function to free the
504 	 * init section since EVA may have used any possible mapping
505 	 * between virtual and physical addresses.
506 	 */
507 	if (free_init_pages_eva)
508 		free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
509 	else
510 		free_initmem_default(POISON_FREE_INITMEM);
511 }
512 
513 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
514 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
515 EXPORT_SYMBOL(__per_cpu_offset);
516 
517 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
518 {
519 	return node_distance(cpu_to_node(from), cpu_to_node(to));
520 }
521 
522 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size,
523 				       size_t align)
524 {
525 	return memblock_alloc_try_nid(size, align, __pa(MAX_DMA_ADDRESS),
526 				      MEMBLOCK_ALLOC_ACCESSIBLE,
527 				      cpu_to_node(cpu));
528 }
529 
530 static void __init pcpu_fc_free(void *ptr, size_t size)
531 {
532 	memblock_free_early(__pa(ptr), size);
533 }
534 
535 void __init setup_per_cpu_areas(void)
536 {
537 	unsigned long delta;
538 	unsigned int cpu;
539 	int rc;
540 
541 	/*
542 	 * Always reserve area for module percpu variables.  That's
543 	 * what the legacy allocator did.
544 	 */
545 	rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
546 				    PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
547 				    pcpu_cpu_distance,
548 				    pcpu_fc_alloc, pcpu_fc_free);
549 	if (rc < 0)
550 		panic("Failed to initialize percpu areas.");
551 
552 	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
553 	for_each_possible_cpu(cpu)
554 		__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
555 }
556 #endif
557 
558 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
559 unsigned long pgd_current[NR_CPUS];
560 #endif
561 
562 /*
563  * Align swapper_pg_dir in to 64K, allows its address to be loaded
564  * with a single LUI instruction in the TLB handlers.  If we used
565  * __aligned(64K), its size would get rounded up to the alignment
566  * size, and waste space.  So we place it in its own section and align
567  * it in the linker script.
568  */
569 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
570 #ifndef __PAGETABLE_PUD_FOLDED
571 pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
572 #endif
573 #ifndef __PAGETABLE_PMD_FOLDED
574 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
575 EXPORT_SYMBOL_GPL(invalid_pmd_table);
576 #endif
577 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
578 EXPORT_SYMBOL(invalid_pte_table);
579