xref: /linux/arch/mips/mm/init.c (revision e1a3e724a25761a2b2e9e0e059e33afac6409a76) 
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/module.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/bootmem.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 
34 #include <asm/asm-offsets.h>
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 long vaddr, flags, entrylo;
88 	unsigned long old_ctx;
89 	pte_t pte;
90 	int tlbidx;
91 
92 	BUG_ON(Page_dcache_dirty(page));
93 
94 	preempt_disable();
95 	pagefault_disable();
96 	idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
97 	idx += in_interrupt() ? FIX_N_COLOURS : 0;
98 	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
99 	pte = mk_pte(page, prot);
100 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
101 	entrylo = pte_to_entrylo(pte.pte_high);
102 #else
103 	entrylo = pte_to_entrylo(pte_val(pte));
104 #endif
105 
106 	local_irq_save(flags);
107 	old_ctx = read_c0_entryhi();
108 	write_c0_entryhi(vaddr & (PAGE_MASK << 1));
109 	write_c0_entrylo0(entrylo);
110 	write_c0_entrylo1(entrylo);
111 #ifdef CONFIG_XPA
112 	entrylo = (pte.pte_low & _PFNX_MASK);
113 	writex_c0_entrylo0(entrylo);
114 	writex_c0_entrylo1(entrylo);
115 #endif
116 	tlbidx = read_c0_wired();
117 	write_c0_wired(tlbidx + 1);
118 	write_c0_index(tlbidx);
119 	mtc0_tlbw_hazard();
120 	tlb_write_indexed();
121 	tlbw_use_hazard();
122 	write_c0_entryhi(old_ctx);
123 	local_irq_restore(flags);
124 
125 	return (void*) vaddr;
126 }
127 
128 void *kmap_coherent(struct page *page, unsigned long addr)
129 {
130 	return __kmap_pgprot(page, addr, PAGE_KERNEL);
131 }
132 
133 void *kmap_noncoherent(struct page *page, unsigned long addr)
134 {
135 	return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
136 }
137 
138 void kunmap_coherent(void)
139 {
140 	unsigned int wired;
141 	unsigned long flags, old_ctx;
142 
143 	local_irq_save(flags);
144 	old_ctx = read_c0_entryhi();
145 	wired = read_c0_wired() - 1;
146 	write_c0_wired(wired);
147 	write_c0_index(wired);
148 	write_c0_entryhi(UNIQUE_ENTRYHI(wired));
149 	write_c0_entrylo0(0);
150 	write_c0_entrylo1(0);
151 	mtc0_tlbw_hazard();
152 	tlb_write_indexed();
153 	tlbw_use_hazard();
154 	write_c0_entryhi(old_ctx);
155 	local_irq_restore(flags);
156 	pagefault_enable();
157 	preempt_enable();
158 }
159 
160 void copy_user_highpage(struct page *to, struct page *from,
161 	unsigned long vaddr, struct vm_area_struct *vma)
162 {
163 	void *vfrom, *vto;
164 
165 	vto = kmap_atomic(to);
166 	if (cpu_has_dc_aliases &&
167 	    page_mapped(from) && !Page_dcache_dirty(from)) {
168 		vfrom = kmap_coherent(from, vaddr);
169 		copy_page(vto, vfrom);
170 		kunmap_coherent();
171 	} else {
172 		vfrom = kmap_atomic(from);
173 		copy_page(vto, vfrom);
174 		kunmap_atomic(vfrom);
175 	}
176 	if ((!cpu_has_ic_fills_f_dc) ||
177 	    pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
178 		flush_data_cache_page((unsigned long)vto);
179 	kunmap_atomic(vto);
180 	/* Make sure this page is cleared on other CPU's too before using it */
181 	smp_wmb();
182 }
183 
184 void copy_to_user_page(struct vm_area_struct *vma,
185 	struct page *page, unsigned long vaddr, void *dst, const void *src,
186 	unsigned long len)
187 {
188 	if (cpu_has_dc_aliases &&
189 	    page_mapped(page) && !Page_dcache_dirty(page)) {
190 		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
191 		memcpy(vto, src, len);
192 		kunmap_coherent();
193 	} else {
194 		memcpy(dst, src, len);
195 		if (cpu_has_dc_aliases)
196 			SetPageDcacheDirty(page);
197 	}
198 	if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
199 		flush_cache_page(vma, vaddr, page_to_pfn(page));
200 }
201 
202 void copy_from_user_page(struct vm_area_struct *vma,
203 	struct page *page, unsigned long vaddr, void *dst, const void *src,
204 	unsigned long len)
205 {
206 	if (cpu_has_dc_aliases &&
207 	    page_mapped(page) && !Page_dcache_dirty(page)) {
208 		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
209 		memcpy(dst, vfrom, len);
210 		kunmap_coherent();
211 	} else {
212 		memcpy(dst, src, len);
213 		if (cpu_has_dc_aliases)
214 			SetPageDcacheDirty(page);
215 	}
216 }
217 EXPORT_SYMBOL_GPL(copy_from_user_page);
218 
219 void __init fixrange_init(unsigned long start, unsigned long end,
220 	pgd_t *pgd_base)
221 {
222 #ifdef CONFIG_HIGHMEM
223 	pgd_t *pgd;
224 	pud_t *pud;
225 	pmd_t *pmd;
226 	pte_t *pte;
227 	int i, j, k;
228 	unsigned long vaddr;
229 
230 	vaddr = start;
231 	i = __pgd_offset(vaddr);
232 	j = __pud_offset(vaddr);
233 	k = __pmd_offset(vaddr);
234 	pgd = pgd_base + i;
235 
236 	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
237 		pud = (pud_t *)pgd;
238 		for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
239 			pmd = (pmd_t *)pud;
240 			for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
241 				if (pmd_none(*pmd)) {
242 					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
243 					set_pmd(pmd, __pmd((unsigned long)pte));
244 					BUG_ON(pte != pte_offset_kernel(pmd, 0));
245 				}
246 				vaddr += PMD_SIZE;
247 			}
248 			k = 0;
249 		}
250 		j = 0;
251 	}
252 #endif
253 }
254 
255 #ifndef CONFIG_NEED_MULTIPLE_NODES
256 int page_is_ram(unsigned long pagenr)
257 {
258 	int i;
259 
260 	for (i = 0; i < boot_mem_map.nr_map; i++) {
261 		unsigned long addr, end;
262 
263 		switch (boot_mem_map.map[i].type) {
264 		case BOOT_MEM_RAM:
265 		case BOOT_MEM_INIT_RAM:
266 			break;
267 		default:
268 			/* not usable memory */
269 			continue;
270 		}
271 
272 		addr = PFN_UP(boot_mem_map.map[i].addr);
273 		end = PFN_DOWN(boot_mem_map.map[i].addr +
274 			       boot_mem_map.map[i].size);
275 
276 		if (pagenr >= addr && pagenr < end)
277 			return 1;
278 	}
279 
280 	return 0;
281 }
282 
283 void __init paging_init(void)
284 {
285 	unsigned long max_zone_pfns[MAX_NR_ZONES];
286 	unsigned long lastpfn __maybe_unused;
287 
288 	pagetable_init();
289 
290 #ifdef CONFIG_HIGHMEM
291 	kmap_init();
292 #endif
293 #ifdef CONFIG_ZONE_DMA
294 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
295 #endif
296 #ifdef CONFIG_ZONE_DMA32
297 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
298 #endif
299 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
300 	lastpfn = max_low_pfn;
301 #ifdef CONFIG_HIGHMEM
302 	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
303 	lastpfn = highend_pfn;
304 
305 	if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
306 		printk(KERN_WARNING "This processor doesn't support highmem."
307 		       " %ldk highmem ignored\n",
308 		       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
309 		max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
310 		lastpfn = max_low_pfn;
311 	}
312 #endif
313 
314 	free_area_init_nodes(max_zone_pfns);
315 }
316 
317 #ifdef CONFIG_64BIT
318 static struct kcore_list kcore_kseg0;
319 #endif
320 
321 static inline void mem_init_free_highmem(void)
322 {
323 #ifdef CONFIG_HIGHMEM
324 	unsigned long tmp;
325 
326 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
327 		struct page *page = pfn_to_page(tmp);
328 
329 		if (!page_is_ram(tmp))
330 			SetPageReserved(page);
331 		else
332 			free_highmem_page(page);
333 	}
334 #endif
335 }
336 
337 unsigned __weak platform_maar_init(unsigned num_pairs)
338 {
339 	struct maar_config cfg[BOOT_MEM_MAP_MAX];
340 	unsigned i, num_configured, num_cfg = 0;
341 	phys_addr_t skip;
342 
343 	for (i = 0; i < boot_mem_map.nr_map; i++) {
344 		switch (boot_mem_map.map[i].type) {
345 		case BOOT_MEM_RAM:
346 		case BOOT_MEM_INIT_RAM:
347 			break;
348 		default:
349 			continue;
350 		}
351 
352 		skip = 0x10000 - (boot_mem_map.map[i].addr & 0xffff);
353 
354 		cfg[num_cfg].lower = boot_mem_map.map[i].addr;
355 		cfg[num_cfg].lower += skip;
356 
357 		cfg[num_cfg].upper = cfg[num_cfg].lower;
358 		cfg[num_cfg].upper += boot_mem_map.map[i].size - 1;
359 		cfg[num_cfg].upper -= skip;
360 
361 		cfg[num_cfg].attrs = MIPS_MAAR_S;
362 		num_cfg++;
363 	}
364 
365 	num_configured = maar_config(cfg, num_cfg, num_pairs);
366 	if (num_configured < num_cfg)
367 		pr_warn("Not enough MAAR pairs (%u) for all bootmem regions (%u)\n",
368 			num_pairs, num_cfg);
369 
370 	return num_configured;
371 }
372 
373 static void maar_init(void)
374 {
375 	unsigned num_maars, used, i;
376 
377 	if (!cpu_has_maar)
378 		return;
379 
380 	/* Detect the number of MAARs */
381 	write_c0_maari(~0);
382 	back_to_back_c0_hazard();
383 	num_maars = read_c0_maari() + 1;
384 
385 	/* MAARs should be in pairs */
386 	WARN_ON(num_maars % 2);
387 
388 	/* Configure the required MAARs */
389 	used = platform_maar_init(num_maars / 2);
390 
391 	/* Disable any further MAARs */
392 	for (i = (used * 2); i < num_maars; i++) {
393 		write_c0_maari(i);
394 		back_to_back_c0_hazard();
395 		write_c0_maar(0);
396 		back_to_back_c0_hazard();
397 	}
398 }
399 
400 void __init mem_init(void)
401 {
402 #ifdef CONFIG_HIGHMEM
403 #ifdef CONFIG_DISCONTIGMEM
404 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
405 #endif
406 	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
407 #else
408 	max_mapnr = max_low_pfn;
409 #endif
410 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
411 
412 	maar_init();
413 	free_all_bootmem();
414 	setup_zero_pages();	/* Setup zeroed pages.  */
415 	mem_init_free_highmem();
416 	mem_init_print_info(NULL);
417 
418 #ifdef CONFIG_64BIT
419 	if ((unsigned long) &_text > (unsigned long) CKSEG0)
420 		/* The -4 is a hack so that user tools don't have to handle
421 		   the overflow.  */
422 		kclist_add(&kcore_kseg0, (void *) CKSEG0,
423 				0x80000000 - 4, KCORE_TEXT);
424 #endif
425 }
426 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
427 
428 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
429 {
430 	unsigned long pfn;
431 
432 	for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
433 		struct page *page = pfn_to_page(pfn);
434 		void *addr = phys_to_virt(PFN_PHYS(pfn));
435 
436 		memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
437 		free_reserved_page(page);
438 	}
439 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
440 }
441 
442 #ifdef CONFIG_BLK_DEV_INITRD
443 void free_initrd_mem(unsigned long start, unsigned long end)
444 {
445 	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
446 			   "initrd");
447 }
448 #endif
449 
450 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
451 
452 void __init_refok free_initmem(void)
453 {
454 	prom_free_prom_memory();
455 	/*
456 	 * Let the platform define a specific function to free the
457 	 * init section since EVA may have used any possible mapping
458 	 * between virtual and physical addresses.
459 	 */
460 	if (free_init_pages_eva)
461 		free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
462 	else
463 		free_initmem_default(POISON_FREE_INITMEM);
464 }
465 
466 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
467 unsigned long pgd_current[NR_CPUS];
468 #endif
469 
470 /*
471  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
472  * are constants.  So we use the variants from asm-offset.h until that gcc
473  * will officially be retired.
474  *
475  * Align swapper_pg_dir in to 64K, allows its address to be loaded
476  * with a single LUI instruction in the TLB handlers.  If we used
477  * __aligned(64K), its size would get rounded up to the alignment
478  * size, and waste space.  So we place it in its own section and align
479  * it in the linker script.
480  */
481 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
482 #ifndef __PAGETABLE_PMD_FOLDED
483 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
484 #endif
485 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
486