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 */
54unsigned long empty_zero_page, zero_page_mask;
55EXPORT_SYMBOL_GPL(empty_zero_page);
56EXPORT_SYMBOL(zero_page_mask);
57
58/*
59 * Not static inline because used by IP27 special magic initialization code
60 */
61void 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
83static 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	pagefault_disable();
94	idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
95	idx += in_interrupt() ? FIX_N_COLOURS : 0;
96	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
97	pte = mk_pte(page, prot);
98#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
99	entrylo = pte_to_entrylo(pte.pte_high);
100#else
101	entrylo = pte_to_entrylo(pte_val(pte));
102#endif
103
104	local_irq_save(flags);
105	old_ctx = read_c0_entryhi();
106	write_c0_entryhi(vaddr & (PAGE_MASK << 1));
107	write_c0_entrylo0(entrylo);
108	write_c0_entrylo1(entrylo);
109#ifdef CONFIG_XPA
110	entrylo = (pte.pte_low & _PFNX_MASK);
111	writex_c0_entrylo0(entrylo);
112	writex_c0_entrylo1(entrylo);
113#endif
114	tlbidx = read_c0_wired();
115	write_c0_wired(tlbidx + 1);
116	write_c0_index(tlbidx);
117	mtc0_tlbw_hazard();
118	tlb_write_indexed();
119	tlbw_use_hazard();
120	write_c0_entryhi(old_ctx);
121	local_irq_restore(flags);
122
123	return (void*) vaddr;
124}
125
126void *kmap_coherent(struct page *page, unsigned long addr)
127{
128	return __kmap_pgprot(page, addr, PAGE_KERNEL);
129}
130
131void *kmap_noncoherent(struct page *page, unsigned long addr)
132{
133	return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
134}
135
136void kunmap_coherent(void)
137{
138	unsigned int wired;
139	unsigned long flags, old_ctx;
140
141	local_irq_save(flags);
142	old_ctx = read_c0_entryhi();
143	wired = read_c0_wired() - 1;
144	write_c0_wired(wired);
145	write_c0_index(wired);
146	write_c0_entryhi(UNIQUE_ENTRYHI(wired));
147	write_c0_entrylo0(0);
148	write_c0_entrylo1(0);
149	mtc0_tlbw_hazard();
150	tlb_write_indexed();
151	tlbw_use_hazard();
152	write_c0_entryhi(old_ctx);
153	local_irq_restore(flags);
154	pagefault_enable();
155}
156
157void copy_user_highpage(struct page *to, struct page *from,
158	unsigned long vaddr, struct vm_area_struct *vma)
159{
160	void *vfrom, *vto;
161
162	vto = kmap_atomic(to);
163	if (cpu_has_dc_aliases &&
164	    page_mapped(from) && !Page_dcache_dirty(from)) {
165		vfrom = kmap_coherent(from, vaddr);
166		copy_page(vto, vfrom);
167		kunmap_coherent();
168	} else {
169		vfrom = kmap_atomic(from);
170		copy_page(vto, vfrom);
171		kunmap_atomic(vfrom);
172	}
173	if ((!cpu_has_ic_fills_f_dc) ||
174	    pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
175		flush_data_cache_page((unsigned long)vto);
176	kunmap_atomic(vto);
177	/* Make sure this page is cleared on other CPU's too before using it */
178	smp_wmb();
179}
180
181void copy_to_user_page(struct vm_area_struct *vma,
182	struct page *page, unsigned long vaddr, void *dst, const void *src,
183	unsigned long len)
184{
185	if (cpu_has_dc_aliases &&
186	    page_mapped(page) && !Page_dcache_dirty(page)) {
187		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
188		memcpy(vto, src, len);
189		kunmap_coherent();
190	} else {
191		memcpy(dst, src, len);
192		if (cpu_has_dc_aliases)
193			SetPageDcacheDirty(page);
194	}
195	if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
196		flush_cache_page(vma, vaddr, page_to_pfn(page));
197}
198
199void copy_from_user_page(struct vm_area_struct *vma,
200	struct page *page, unsigned long vaddr, void *dst, const void *src,
201	unsigned long len)
202{
203	if (cpu_has_dc_aliases &&
204	    page_mapped(page) && !Page_dcache_dirty(page)) {
205		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
206		memcpy(dst, vfrom, len);
207		kunmap_coherent();
208	} else {
209		memcpy(dst, src, len);
210		if (cpu_has_dc_aliases)
211			SetPageDcacheDirty(page);
212	}
213}
214EXPORT_SYMBOL_GPL(copy_from_user_page);
215
216void __init fixrange_init(unsigned long start, unsigned long end,
217	pgd_t *pgd_base)
218{
219#ifdef CONFIG_HIGHMEM
220	pgd_t *pgd;
221	pud_t *pud;
222	pmd_t *pmd;
223	pte_t *pte;
224	int i, j, k;
225	unsigned long vaddr;
226
227	vaddr = start;
228	i = __pgd_offset(vaddr);
229	j = __pud_offset(vaddr);
230	k = __pmd_offset(vaddr);
231	pgd = pgd_base + i;
232
233	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
234		pud = (pud_t *)pgd;
235		for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
236			pmd = (pmd_t *)pud;
237			for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
238				if (pmd_none(*pmd)) {
239					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
240					set_pmd(pmd, __pmd((unsigned long)pte));
241					BUG_ON(pte != pte_offset_kernel(pmd, 0));
242				}
243				vaddr += PMD_SIZE;
244			}
245			k = 0;
246		}
247		j = 0;
248	}
249#endif
250}
251
252#ifndef CONFIG_NEED_MULTIPLE_NODES
253int page_is_ram(unsigned long pagenr)
254{
255	int i;
256
257	for (i = 0; i < boot_mem_map.nr_map; i++) {
258		unsigned long addr, end;
259
260		switch (boot_mem_map.map[i].type) {
261		case BOOT_MEM_RAM:
262		case BOOT_MEM_INIT_RAM:
263			break;
264		default:
265			/* not usable memory */
266			continue;
267		}
268
269		addr = PFN_UP(boot_mem_map.map[i].addr);
270		end = PFN_DOWN(boot_mem_map.map[i].addr +
271			       boot_mem_map.map[i].size);
272
273		if (pagenr >= addr && pagenr < end)
274			return 1;
275	}
276
277	return 0;
278}
279
280void __init paging_init(void)
281{
282	unsigned long max_zone_pfns[MAX_NR_ZONES];
283	unsigned long lastpfn __maybe_unused;
284
285	pagetable_init();
286
287#ifdef CONFIG_HIGHMEM
288	kmap_init();
289#endif
290#ifdef CONFIG_ZONE_DMA
291	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
292#endif
293#ifdef CONFIG_ZONE_DMA32
294	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
295#endif
296	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
297	lastpfn = max_low_pfn;
298#ifdef CONFIG_HIGHMEM
299	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
300	lastpfn = highend_pfn;
301
302	if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
303		printk(KERN_WARNING "This processor doesn't support highmem."
304		       " %ldk highmem ignored\n",
305		       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
306		max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
307		lastpfn = max_low_pfn;
308	}
309#endif
310
311	free_area_init_nodes(max_zone_pfns);
312}
313
314#ifdef CONFIG_64BIT
315static struct kcore_list kcore_kseg0;
316#endif
317
318static inline void mem_init_free_highmem(void)
319{
320#ifdef CONFIG_HIGHMEM
321	unsigned long tmp;
322
323	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
324		struct page *page = pfn_to_page(tmp);
325
326		if (!page_is_ram(tmp))
327			SetPageReserved(page);
328		else
329			free_highmem_page(page);
330	}
331#endif
332}
333
334unsigned __weak platform_maar_init(unsigned num_maars)
335{
336	return 0;
337}
338
339static void maar_init(void)
340{
341	unsigned num_maars, used, i;
342
343	if (!cpu_has_maar)
344		return;
345
346	/* Detect the number of MAARs */
347	write_c0_maari(~0);
348	back_to_back_c0_hazard();
349	num_maars = read_c0_maari() + 1;
350
351	/* MAARs should be in pairs */
352	WARN_ON(num_maars % 2);
353
354	/* Configure the required MAARs */
355	used = platform_maar_init(num_maars / 2);
356
357	/* Disable any further MAARs */
358	for (i = (used * 2); i < num_maars; i++) {
359		write_c0_maari(i);
360		back_to_back_c0_hazard();
361		write_c0_maar(0);
362		back_to_back_c0_hazard();
363	}
364}
365
366void __init mem_init(void)
367{
368#ifdef CONFIG_HIGHMEM
369#ifdef CONFIG_DISCONTIGMEM
370#error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
371#endif
372	max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
373#else
374	max_mapnr = max_low_pfn;
375#endif
376	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
377
378	maar_init();
379	free_all_bootmem();
380	setup_zero_pages();	/* Setup zeroed pages.  */
381	mem_init_free_highmem();
382	mem_init_print_info(NULL);
383
384#ifdef CONFIG_64BIT
385	if ((unsigned long) &_text > (unsigned long) CKSEG0)
386		/* The -4 is a hack so that user tools don't have to handle
387		   the overflow.  */
388		kclist_add(&kcore_kseg0, (void *) CKSEG0,
389				0x80000000 - 4, KCORE_TEXT);
390#endif
391}
392#endif /* !CONFIG_NEED_MULTIPLE_NODES */
393
394void free_init_pages(const char *what, unsigned long begin, unsigned long end)
395{
396	unsigned long pfn;
397
398	for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
399		struct page *page = pfn_to_page(pfn);
400		void *addr = phys_to_virt(PFN_PHYS(pfn));
401
402		memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
403		free_reserved_page(page);
404	}
405	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
406}
407
408#ifdef CONFIG_BLK_DEV_INITRD
409void free_initrd_mem(unsigned long start, unsigned long end)
410{
411	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
412			   "initrd");
413}
414#endif
415
416void (*free_init_pages_eva)(void *begin, void *end) = NULL;
417
418void __init_refok free_initmem(void)
419{
420	prom_free_prom_memory();
421	/*
422	 * Let the platform define a specific function to free the
423	 * init section since EVA may have used any possible mapping
424	 * between virtual and physical addresses.
425	 */
426	if (free_init_pages_eva)
427		free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
428	else
429		free_initmem_default(POISON_FREE_INITMEM);
430}
431
432#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
433unsigned long pgd_current[NR_CPUS];
434#endif
435
436/*
437 * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
438 * are constants.  So we use the variants from asm-offset.h until that gcc
439 * will officially be retired.
440 *
441 * Align swapper_pg_dir in to 64K, allows its address to be loaded
442 * with a single LUI instruction in the TLB handlers.  If we used
443 * __aligned(64K), its size would get rounded up to the alignment
444 * size, and waste space.  So we place it in its own section and align
445 * it in the linker script.
446 */
447pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
448#ifndef __PAGETABLE_PMD_FOLDED
449pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
450#endif
451pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
452