xref: /openbmc/linux/arch/mips/mm/init.c (revision 3b27d139) 
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/mmu_context.h>
41 #include <asm/sections.h>
42 #include <asm/pgtable.h>
43 #include <asm/pgalloc.h>
44 #include <asm/tlb.h>
45 #include <asm/fixmap.h>
46 
47 /*
48  * We have up to 8 empty zeroed pages so we can map one of the right colour
49  * when needed.	 This is necessary only on R4000 / R4400 SC and MC versions
50  * where we have to avoid VCED / VECI exceptions for good performance at
51  * any price.  Since page is never written to after the initialization we
52  * don't have to care about aliases on other CPUs.
53  */
54 unsigned long empty_zero_page, zero_page_mask;
55 EXPORT_SYMBOL_GPL(empty_zero_page);
56 EXPORT_SYMBOL(zero_page_mask);
57 
58 /*
59  * Not static inline because used by IP27 special magic initialization code
60  */
61 void setup_zero_pages(void)
62 {
63 	unsigned int order, i;
64 	struct page *page;
65 
66 	if (cpu_has_vce)
67 		order = 3;
68 	else
69 		order = 0;
70 
71 	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
72 	if (!empty_zero_page)
73 		panic("Oh boy, that early out of memory?");
74 
75 	page = virt_to_page((void *)empty_zero_page);
76 	split_page(page, order);
77 	for (i = 0; i < (1 << order); i++, page++)
78 		mark_page_reserved(page);
79 
80 	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
81 }
82 
83 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
84 {
85 	enum fixed_addresses idx;
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_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
100 	entrylo = pte_to_entrylo(pte.pte_high);
101 #else
102 	entrylo = pte_to_entrylo(pte_val(pte));
103 #endif
104 
105 	local_irq_save(flags);
106 	old_ctx = read_c0_entryhi();
107 	write_c0_entryhi(vaddr & (PAGE_MASK << 1));
108 	write_c0_entrylo0(entrylo);
109 	write_c0_entrylo1(entrylo);
110 #ifdef CONFIG_XPA
111 	entrylo = (pte.pte_low & _PFNX_MASK);
112 	writex_c0_entrylo0(entrylo);
113 	writex_c0_entrylo1(entrylo);
114 #endif
115 	tlbidx = read_c0_wired();
116 	write_c0_wired(tlbidx + 1);
117 	write_c0_index(tlbidx);
118 	mtc0_tlbw_hazard();
119 	tlb_write_indexed();
120 	tlbw_use_hazard();
121 	write_c0_entryhi(old_ctx);
122 	local_irq_restore(flags);
123 
124 	return (void*) vaddr;
125 }
126 
127 void *kmap_coherent(struct page *page, unsigned long addr)
128 {
129 	return __kmap_pgprot(page, addr, PAGE_KERNEL);
130 }
131 
132 void *kmap_noncoherent(struct page *page, unsigned long addr)
133 {
134 	return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
135 }
136 
137 void kunmap_coherent(void)
138 {
139 	unsigned int wired;
140 	unsigned long flags, old_ctx;
141 
142 	local_irq_save(flags);
143 	old_ctx = read_c0_entryhi();
144 	wired = read_c0_wired() - 1;
145 	write_c0_wired(wired);
146 	write_c0_index(wired);
147 	write_c0_entryhi(UNIQUE_ENTRYHI(wired));
148 	write_c0_entrylo0(0);
149 	write_c0_entrylo1(0);
150 	mtc0_tlbw_hazard();
151 	tlb_write_indexed();
152 	tlbw_use_hazard();
153 	write_c0_entryhi(old_ctx);
154 	local_irq_restore(flags);
155 	pagefault_enable();
156 	preempt_enable();
157 }
158 
159 void copy_user_highpage(struct page *to, struct page *from,
160 	unsigned long vaddr, struct vm_area_struct *vma)
161 {
162 	void *vfrom, *vto;
163 
164 	vto = kmap_atomic(to);
165 	if (cpu_has_dc_aliases &&
166 	    page_mapped(from) && !Page_dcache_dirty(from)) {
167 		vfrom = kmap_coherent(from, vaddr);
168 		copy_page(vto, vfrom);
169 		kunmap_coherent();
170 	} else {
171 		vfrom = kmap_atomic(from);
172 		copy_page(vto, vfrom);
173 		kunmap_atomic(vfrom);
174 	}
175 	if ((!cpu_has_ic_fills_f_dc) ||
176 	    pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
177 		flush_data_cache_page((unsigned long)vto);
178 	kunmap_atomic(vto);
179 	/* Make sure this page is cleared on other CPU's too before using it */
180 	smp_wmb();
181 }
182 
183 void copy_to_user_page(struct vm_area_struct *vma,
184 	struct page *page, unsigned long vaddr, void *dst, const void *src,
185 	unsigned long len)
186 {
187 	if (cpu_has_dc_aliases &&
188 	    page_mapped(page) && !Page_dcache_dirty(page)) {
189 		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
190 		memcpy(vto, src, len);
191 		kunmap_coherent();
192 	} else {
193 		memcpy(dst, src, len);
194 		if (cpu_has_dc_aliases)
195 			SetPageDcacheDirty(page);
196 	}
197 	if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
198 		flush_cache_page(vma, vaddr, page_to_pfn(page));
199 }
200 
201 void copy_from_user_page(struct vm_area_struct *vma,
202 	struct page *page, unsigned long vaddr, void *dst, const void *src,
203 	unsigned long len)
204 {
205 	if (cpu_has_dc_aliases &&
206 	    page_mapped(page) && !Page_dcache_dirty(page)) {
207 		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
208 		memcpy(dst, vfrom, len);
209 		kunmap_coherent();
210 	} else {
211 		memcpy(dst, src, len);
212 		if (cpu_has_dc_aliases)
213 			SetPageDcacheDirty(page);
214 	}
215 }
216 EXPORT_SYMBOL_GPL(copy_from_user_page);
217 
218 void __init fixrange_init(unsigned long start, unsigned long end,
219 	pgd_t *pgd_base)
220 {
221 #ifdef CONFIG_HIGHMEM
222 	pgd_t *pgd;
223 	pud_t *pud;
224 	pmd_t *pmd;
225 	pte_t *pte;
226 	int i, j, k;
227 	unsigned long vaddr;
228 
229 	vaddr = start;
230 	i = __pgd_offset(vaddr);
231 	j = __pud_offset(vaddr);
232 	k = __pmd_offset(vaddr);
233 	pgd = pgd_base + i;
234 
235 	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
236 		pud = (pud_t *)pgd;
237 		for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
238 			pmd = (pmd_t *)pud;
239 			for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
240 				if (pmd_none(*pmd)) {
241 					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
242 					set_pmd(pmd, __pmd((unsigned long)pte));
243 					BUG_ON(pte != pte_offset_kernel(pmd, 0));
244 				}
245 				vaddr += PMD_SIZE;
246 			}
247 			k = 0;
248 		}
249 		j = 0;
250 	}
251 #endif
252 }
253 
254 #ifndef CONFIG_NEED_MULTIPLE_NODES
255 int page_is_ram(unsigned long pagenr)
256 {
257 	int i;
258 
259 	for (i = 0; i < boot_mem_map.nr_map; i++) {
260 		unsigned long addr, end;
261 
262 		switch (boot_mem_map.map[i].type) {
263 		case BOOT_MEM_RAM:
264 		case BOOT_MEM_INIT_RAM:
265 			break;
266 		default:
267 			/* not usable memory */
268 			continue;
269 		}
270 
271 		addr = PFN_UP(boot_mem_map.map[i].addr);
272 		end = PFN_DOWN(boot_mem_map.map[i].addr +
273 			       boot_mem_map.map[i].size);
274 
275 		if (pagenr >= addr && pagenr < end)
276 			return 1;
277 	}
278 
279 	return 0;
280 }
281 
282 void __init paging_init(void)
283 {
284 	unsigned long max_zone_pfns[MAX_NR_ZONES];
285 	unsigned long lastpfn __maybe_unused;
286 
287 	pagetable_init();
288 
289 #ifdef CONFIG_HIGHMEM
290 	kmap_init();
291 #endif
292 #ifdef CONFIG_ZONE_DMA
293 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
294 #endif
295 #ifdef CONFIG_ZONE_DMA32
296 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
297 #endif
298 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
299 	lastpfn = max_low_pfn;
300 #ifdef CONFIG_HIGHMEM
301 	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
302 	lastpfn = highend_pfn;
303 
304 	if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
305 		printk(KERN_WARNING "This processor doesn't support highmem."
306 		       " %ldk highmem ignored\n",
307 		       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
308 		max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
309 		lastpfn = max_low_pfn;
310 	}
311 #endif
312 
313 	free_area_init_nodes(max_zone_pfns);
314 }
315 
316 #ifdef CONFIG_64BIT
317 static struct kcore_list kcore_kseg0;
318 #endif
319 
320 static inline void mem_init_free_highmem(void)
321 {
322 #ifdef CONFIG_HIGHMEM
323 	unsigned long tmp;
324 
325 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
326 		struct page *page = pfn_to_page(tmp);
327 
328 		if (!page_is_ram(tmp))
329 			SetPageReserved(page);
330 		else
331 			free_highmem_page(page);
332 	}
333 #endif
334 }
335 
336 unsigned __weak platform_maar_init(unsigned num_maars)
337 {
338 	return 0;
339 }
340 
341 static void maar_init(void)
342 {
343 	unsigned num_maars, used, i;
344 
345 	if (!cpu_has_maar)
346 		return;
347 
348 	/* Detect the number of MAARs */
349 	write_c0_maari(~0);
350 	back_to_back_c0_hazard();
351 	num_maars = read_c0_maari() + 1;
352 
353 	/* MAARs should be in pairs */
354 	WARN_ON(num_maars % 2);
355 
356 	/* Configure the required MAARs */
357 	used = platform_maar_init(num_maars / 2);
358 
359 	/* Disable any further MAARs */
360 	for (i = (used * 2); i < num_maars; i++) {
361 		write_c0_maari(i);
362 		back_to_back_c0_hazard();
363 		write_c0_maar(0);
364 		back_to_back_c0_hazard();
365 	}
366 }
367 
368 void __init mem_init(void)
369 {
370 #ifdef CONFIG_HIGHMEM
371 #ifdef CONFIG_DISCONTIGMEM
372 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
373 #endif
374 	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
375 #else
376 	max_mapnr = max_low_pfn;
377 #endif
378 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
379 
380 	maar_init();
381 	free_all_bootmem();
382 	setup_zero_pages();	/* Setup zeroed pages.  */
383 	mem_init_free_highmem();
384 	mem_init_print_info(NULL);
385 
386 #ifdef CONFIG_64BIT
387 	if ((unsigned long) &_text > (unsigned long) CKSEG0)
388 		/* The -4 is a hack so that user tools don't have to handle
389 		   the overflow.  */
390 		kclist_add(&kcore_kseg0, (void *) CKSEG0,
391 				0x80000000 - 4, KCORE_TEXT);
392 #endif
393 }
394 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
395 
396 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
397 {
398 	unsigned long pfn;
399 
400 	for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
401 		struct page *page = pfn_to_page(pfn);
402 		void *addr = phys_to_virt(PFN_PHYS(pfn));
403 
404 		memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
405 		free_reserved_page(page);
406 	}
407 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
408 }
409 
410 #ifdef CONFIG_BLK_DEV_INITRD
411 void free_initrd_mem(unsigned long start, unsigned long end)
412 {
413 	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
414 			   "initrd");
415 }
416 #endif
417 
418 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
419 
420 void __init_refok free_initmem(void)
421 {
422 	prom_free_prom_memory();
423 	/*
424 	 * Let the platform define a specific function to free the
425 	 * init section since EVA may have used any possible mapping
426 	 * between virtual and physical addresses.
427 	 */
428 	if (free_init_pages_eva)
429 		free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
430 	else
431 		free_initmem_default(POISON_FREE_INITMEM);
432 }
433 
434 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
435 unsigned long pgd_current[NR_CPUS];
436 #endif
437 
438 /*
439  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
440  * are constants.  So we use the variants from asm-offset.h until that gcc
441  * will officially be retired.
442  *
443  * Align swapper_pg_dir in to 64K, allows its address to be loaded
444  * with a single LUI instruction in the TLB handlers.  If we used
445  * __aligned(64K), its size would get rounded up to the alignment
446  * size, and waste space.  So we place it in its own section and align
447  * it in the linker script.
448  */
449 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
450 #ifndef __PAGETABLE_PMD_FOLDED
451 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
452 #endif
453 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
454