xref: /openbmc/linux/arch/mips/mm/init.c (revision b04b4f78)
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/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/string.h>
19 #include <linux/types.h>
20 #include <linux/pagemap.h>
21 #include <linux/ptrace.h>
22 #include <linux/mman.h>
23 #include <linux/mm.h>
24 #include <linux/bootmem.h>
25 #include <linux/highmem.h>
26 #include <linux/swap.h>
27 #include <linux/proc_fs.h>
28 #include <linux/pfn.h>
29 
30 #include <asm/asm-offsets.h>
31 #include <asm/bootinfo.h>
32 #include <asm/cachectl.h>
33 #include <asm/cpu.h>
34 #include <asm/dma.h>
35 #include <asm/kmap_types.h>
36 #include <asm/mmu_context.h>
37 #include <asm/sections.h>
38 #include <asm/pgtable.h>
39 #include <asm/pgalloc.h>
40 #include <asm/tlb.h>
41 #include <asm/fixmap.h>
42 
43 /* Atomicity and interruptability */
44 #ifdef CONFIG_MIPS_MT_SMTC
45 
46 #include <asm/mipsmtregs.h>
47 
48 #define ENTER_CRITICAL(flags) \
49 	{ \
50 	unsigned int mvpflags; \
51 	local_irq_save(flags);\
52 	mvpflags = dvpe()
53 #define EXIT_CRITICAL(flags) \
54 	evpe(mvpflags); \
55 	local_irq_restore(flags); \
56 	}
57 #else
58 
59 #define ENTER_CRITICAL(flags) local_irq_save(flags)
60 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
61 
62 #endif /* CONFIG_MIPS_MT_SMTC */
63 
64 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
65 
66 /*
67  * We have up to 8 empty zeroed pages so we can map one of the right colour
68  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
69  * where we have to avoid VCED / VECI exceptions for good performance at
70  * any price.  Since page is never written to after the initialization we
71  * don't have to care about aliases on other CPUs.
72  */
73 unsigned long empty_zero_page, zero_page_mask;
74 EXPORT_SYMBOL_GPL(empty_zero_page);
75 
76 /*
77  * Not static inline because used by IP27 special magic initialization code
78  */
79 unsigned long setup_zero_pages(void)
80 {
81 	unsigned int order;
82 	unsigned long size;
83 	struct page *page;
84 
85 	if (cpu_has_vce)
86 		order = 3;
87 	else
88 		order = 0;
89 
90 	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
91 	if (!empty_zero_page)
92 		panic("Oh boy, that early out of memory?");
93 
94 	page = virt_to_page((void *)empty_zero_page);
95 	split_page(page, order);
96 	while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
97 		SetPageReserved(page);
98 		page++;
99 	}
100 
101 	size = PAGE_SIZE << order;
102 	zero_page_mask = (size - 1) & PAGE_MASK;
103 
104 	return 1UL << order;
105 }
106 
107 /*
108  * These are almost like kmap_atomic / kunmap_atmic except they take an
109  * additional address argument as the hint.
110  */
111 
112 #define kmap_get_fixmap_pte(vaddr)					\
113 	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
114 
115 #ifdef CONFIG_MIPS_MT_SMTC
116 static pte_t *kmap_coherent_pte;
117 static void __init kmap_coherent_init(void)
118 {
119 	unsigned long vaddr;
120 
121 	/* cache the first coherent kmap pte */
122 	vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
123 	kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
124 }
125 #else
126 static inline void kmap_coherent_init(void) {}
127 #endif
128 
129 void *kmap_coherent(struct page *page, unsigned long addr)
130 {
131 	enum fixed_addresses idx;
132 	unsigned long vaddr, flags, entrylo;
133 	unsigned long old_ctx;
134 	pte_t pte;
135 	int tlbidx;
136 
137 	BUG_ON(Page_dcache_dirty(page));
138 
139 	inc_preempt_count();
140 	idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
141 #ifdef CONFIG_MIPS_MT_SMTC
142 	idx += FIX_N_COLOURS * smp_processor_id();
143 #endif
144 	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
145 	pte = mk_pte(page, PAGE_KERNEL);
146 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
147 	entrylo = pte.pte_high;
148 #else
149 	entrylo = pte_val(pte) >> 6;
150 #endif
151 
152 	ENTER_CRITICAL(flags);
153 	old_ctx = read_c0_entryhi();
154 	write_c0_entryhi(vaddr & (PAGE_MASK << 1));
155 	write_c0_entrylo0(entrylo);
156 	write_c0_entrylo1(entrylo);
157 #ifdef CONFIG_MIPS_MT_SMTC
158 	set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
159 	/* preload TLB instead of local_flush_tlb_one() */
160 	mtc0_tlbw_hazard();
161 	tlb_probe();
162 	tlb_probe_hazard();
163 	tlbidx = read_c0_index();
164 	mtc0_tlbw_hazard();
165 	if (tlbidx < 0)
166 		tlb_write_random();
167 	else
168 		tlb_write_indexed();
169 #else
170 	tlbidx = read_c0_wired();
171 	write_c0_wired(tlbidx + 1);
172 	write_c0_index(tlbidx);
173 	mtc0_tlbw_hazard();
174 	tlb_write_indexed();
175 #endif
176 	tlbw_use_hazard();
177 	write_c0_entryhi(old_ctx);
178 	EXIT_CRITICAL(flags);
179 
180 	return (void*) vaddr;
181 }
182 
183 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
184 
185 void kunmap_coherent(void)
186 {
187 #ifndef CONFIG_MIPS_MT_SMTC
188 	unsigned int wired;
189 	unsigned long flags, old_ctx;
190 
191 	ENTER_CRITICAL(flags);
192 	old_ctx = read_c0_entryhi();
193 	wired = read_c0_wired() - 1;
194 	write_c0_wired(wired);
195 	write_c0_index(wired);
196 	write_c0_entryhi(UNIQUE_ENTRYHI(wired));
197 	write_c0_entrylo0(0);
198 	write_c0_entrylo1(0);
199 	mtc0_tlbw_hazard();
200 	tlb_write_indexed();
201 	tlbw_use_hazard();
202 	write_c0_entryhi(old_ctx);
203 	EXIT_CRITICAL(flags);
204 #endif
205 	dec_preempt_count();
206 	preempt_check_resched();
207 }
208 
209 void copy_user_highpage(struct page *to, struct page *from,
210 	unsigned long vaddr, struct vm_area_struct *vma)
211 {
212 	void *vfrom, *vto;
213 
214 	vto = kmap_atomic(to, KM_USER1);
215 	if (cpu_has_dc_aliases &&
216 	    page_mapped(from) && !Page_dcache_dirty(from)) {
217 		vfrom = kmap_coherent(from, vaddr);
218 		copy_page(vto, vfrom);
219 		kunmap_coherent();
220 	} else {
221 		vfrom = kmap_atomic(from, KM_USER0);
222 		copy_page(vto, vfrom);
223 		kunmap_atomic(vfrom, KM_USER0);
224 	}
225 	if ((!cpu_has_ic_fills_f_dc) ||
226 	    pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
227 		flush_data_cache_page((unsigned long)vto);
228 	kunmap_atomic(vto, KM_USER1);
229 	/* Make sure this page is cleared on other CPU's too before using it */
230 	smp_wmb();
231 }
232 
233 void copy_to_user_page(struct vm_area_struct *vma,
234 	struct page *page, unsigned long vaddr, void *dst, const void *src,
235 	unsigned long len)
236 {
237 	if (cpu_has_dc_aliases &&
238 	    page_mapped(page) && !Page_dcache_dirty(page)) {
239 		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
240 		memcpy(vto, src, len);
241 		kunmap_coherent();
242 	} else {
243 		memcpy(dst, src, len);
244 		if (cpu_has_dc_aliases)
245 			SetPageDcacheDirty(page);
246 	}
247 	if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
248 		flush_cache_page(vma, vaddr, page_to_pfn(page));
249 }
250 
251 void copy_from_user_page(struct vm_area_struct *vma,
252 	struct page *page, unsigned long vaddr, void *dst, const void *src,
253 	unsigned long len)
254 {
255 	if (cpu_has_dc_aliases &&
256 	    page_mapped(page) && !Page_dcache_dirty(page)) {
257 		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
258 		memcpy(dst, vfrom, len);
259 		kunmap_coherent();
260 	} else {
261 		memcpy(dst, src, len);
262 		if (cpu_has_dc_aliases)
263 			SetPageDcacheDirty(page);
264 	}
265 }
266 
267 #ifdef CONFIG_HIGHMEM
268 unsigned long highstart_pfn, highend_pfn;
269 
270 pte_t *kmap_pte;
271 pgprot_t kmap_prot;
272 
273 static void __init kmap_init(void)
274 {
275 	unsigned long kmap_vstart;
276 
277 	/* cache the first kmap pte */
278 	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
279 	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
280 
281 	kmap_prot = PAGE_KERNEL;
282 }
283 #endif /* CONFIG_HIGHMEM */
284 
285 void __init fixrange_init(unsigned long start, unsigned long end,
286 	pgd_t *pgd_base)
287 {
288 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
289 	pgd_t *pgd;
290 	pud_t *pud;
291 	pmd_t *pmd;
292 	pte_t *pte;
293 	int i, j, k;
294 	unsigned long vaddr;
295 
296 	vaddr = start;
297 	i = __pgd_offset(vaddr);
298 	j = __pud_offset(vaddr);
299 	k = __pmd_offset(vaddr);
300 	pgd = pgd_base + i;
301 
302 	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
303 		pud = (pud_t *)pgd;
304 		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
305 			pmd = (pmd_t *)pud;
306 			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
307 				if (pmd_none(*pmd)) {
308 					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
309 					set_pmd(pmd, __pmd((unsigned long)pte));
310 					BUG_ON(pte != pte_offset_kernel(pmd, 0));
311 				}
312 				vaddr += PMD_SIZE;
313 			}
314 			k = 0;
315 		}
316 		j = 0;
317 	}
318 #endif
319 }
320 
321 #ifndef CONFIG_NEED_MULTIPLE_NODES
322 static int __init page_is_ram(unsigned long pagenr)
323 {
324 	int i;
325 
326 	for (i = 0; i < boot_mem_map.nr_map; i++) {
327 		unsigned long addr, end;
328 
329 		if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
330 			/* not usable memory */
331 			continue;
332 
333 		addr = PFN_UP(boot_mem_map.map[i].addr);
334 		end = PFN_DOWN(boot_mem_map.map[i].addr +
335 			       boot_mem_map.map[i].size);
336 
337 		if (pagenr >= addr && pagenr < end)
338 			return 1;
339 	}
340 
341 	return 0;
342 }
343 
344 void __init paging_init(void)
345 {
346 	unsigned long max_zone_pfns[MAX_NR_ZONES];
347 	unsigned long lastpfn;
348 
349 	pagetable_init();
350 
351 #ifdef CONFIG_HIGHMEM
352 	kmap_init();
353 #endif
354 	kmap_coherent_init();
355 
356 #ifdef CONFIG_ZONE_DMA
357 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
358 #endif
359 #ifdef CONFIG_ZONE_DMA32
360 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
361 #endif
362 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
363 	lastpfn = max_low_pfn;
364 #ifdef CONFIG_HIGHMEM
365 	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
366 	lastpfn = highend_pfn;
367 
368 	if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
369 		printk(KERN_WARNING "This processor doesn't support highmem."
370 		       " %ldk highmem ignored\n",
371 		       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
372 		max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
373 		lastpfn = max_low_pfn;
374 	}
375 #endif
376 
377 	free_area_init_nodes(max_zone_pfns);
378 }
379 
380 static struct kcore_list kcore_mem, kcore_vmalloc;
381 #ifdef CONFIG_64BIT
382 static struct kcore_list kcore_kseg0;
383 #endif
384 
385 void __init mem_init(void)
386 {
387 	unsigned long codesize, reservedpages, datasize, initsize;
388 	unsigned long tmp, ram;
389 
390 #ifdef CONFIG_HIGHMEM
391 #ifdef CONFIG_DISCONTIGMEM
392 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
393 #endif
394 	max_mapnr = highend_pfn;
395 #else
396 	max_mapnr = max_low_pfn;
397 #endif
398 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
399 
400 	totalram_pages += free_all_bootmem();
401 	totalram_pages -= setup_zero_pages();	/* Setup zeroed pages.  */
402 
403 	reservedpages = ram = 0;
404 	for (tmp = 0; tmp < max_low_pfn; tmp++)
405 		if (page_is_ram(tmp)) {
406 			ram++;
407 			if (PageReserved(pfn_to_page(tmp)))
408 				reservedpages++;
409 		}
410 	num_physpages = ram;
411 
412 #ifdef CONFIG_HIGHMEM
413 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
414 		struct page *page = pfn_to_page(tmp);
415 
416 		if (!page_is_ram(tmp)) {
417 			SetPageReserved(page);
418 			continue;
419 		}
420 		ClearPageReserved(page);
421 		init_page_count(page);
422 		__free_page(page);
423 		totalhigh_pages++;
424 	}
425 	totalram_pages += totalhigh_pages;
426 	num_physpages += totalhigh_pages;
427 #endif
428 
429 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
430 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
431 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
432 
433 #ifdef CONFIG_64BIT
434 	if ((unsigned long) &_text > (unsigned long) CKSEG0)
435 		/* The -4 is a hack so that user tools don't have to handle
436 		   the overflow.  */
437 		kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
438 #endif
439 	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
440 	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
441 		   VMALLOC_END-VMALLOC_START);
442 
443 	printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
444 	       "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
445 	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
446 	       ram << (PAGE_SHIFT-10),
447 	       codesize >> 10,
448 	       reservedpages << (PAGE_SHIFT-10),
449 	       datasize >> 10,
450 	       initsize >> 10,
451 	       (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
452 }
453 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
454 
455 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
456 {
457 	unsigned long pfn;
458 
459 	for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
460 		struct page *page = pfn_to_page(pfn);
461 		void *addr = phys_to_virt(PFN_PHYS(pfn));
462 
463 		ClearPageReserved(page);
464 		init_page_count(page);
465 		memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
466 		__free_page(page);
467 		totalram_pages++;
468 	}
469 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
470 }
471 
472 #ifdef CONFIG_BLK_DEV_INITRD
473 void free_initrd_mem(unsigned long start, unsigned long end)
474 {
475 	free_init_pages("initrd memory",
476 			virt_to_phys((void *)start),
477 			virt_to_phys((void *)end));
478 }
479 #endif
480 
481 void __init_refok free_initmem(void)
482 {
483 	prom_free_prom_memory();
484 	free_init_pages("unused kernel memory",
485 			__pa_symbol(&__init_begin),
486 			__pa_symbol(&__init_end));
487 }
488 
489 unsigned long pgd_current[NR_CPUS];
490 /*
491  * On 64-bit we've got three-level pagetables with a slightly
492  * different layout ...
493  */
494 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
495 
496 /*
497  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
498  * are constants.  So we use the variants from asm-offset.h until that gcc
499  * will officially be retired.
500  */
501 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
502 #ifdef CONFIG_64BIT
503 #ifdef MODULE_START
504 pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
505 #endif
506 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
507 #endif
508 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
509