summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/mm/init_64.c
blob: 95a45293e5ac0dd2c6b343f1aa7a81ed8b69b666 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  Dave Engebretsen <engebret@us.ibm.com>
 *      Rework for PPC64 port.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#undef DEBUG

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/idr.h>
#include <linux/nodemask.h>
#include <linux/module.h>
#include <linux/poison.h>
#include <linux/memblock.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>

#include <asm/pgalloc.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/uaccess.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/tlb.h>
#include <asm/eeh.h>
#include <asm/processor.h>
#include <asm/mmzone.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/iommu.h>
#include <asm/vdso.h>

#include "mmu_decl.h"

#ifdef CONFIG_PPC_STD_MMU_64
#if PGTABLE_RANGE > USER_VSID_RANGE
#warning Limited user VSID range means pagetable space is wasted
#endif

#if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE)
#warning TASK_SIZE is smaller than it needs to be.
#endif
#endif /* CONFIG_PPC_STD_MMU_64 */

phys_addr_t memstart_addr = ~0;
EXPORT_SYMBOL_GPL(memstart_addr);
phys_addr_t kernstart_addr;
EXPORT_SYMBOL_GPL(kernstart_addr);

static void pgd_ctor(void *addr)
{
	memset(addr, 0, PGD_TABLE_SIZE);
}

static void pmd_ctor(void *addr)
{
	memset(addr, 0, PMD_TABLE_SIZE);
}

struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];

/*
 * Create a kmem_cache() for pagetables.  This is not used for PTE
 * pages - they're linked to struct page, come from the normal free
 * pages pool and have a different entry size (see real_pte_t) to
 * everything else.  Caches created by this function are used for all
 * the higher level pagetables, and for hugepage pagetables.
 */
void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
{
	char *name;
	unsigned long table_size = sizeof(void *) << shift;
	unsigned long align = table_size;

	/* When batching pgtable pointers for RCU freeing, we store
	 * the index size in the low bits.  Table alignment must be
	 * big enough to fit it.
	 *
	 * Likewise, hugeapge pagetable pointers contain a (different)
	 * shift value in the low bits.  All tables must be aligned so
	 * as to leave enough 0 bits in the address to contain it. */
	unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
				     HUGEPD_SHIFT_MASK + 1);
	struct kmem_cache *new;

	/* It would be nice if this was a BUILD_BUG_ON(), but at the
	 * moment, gcc doesn't seem to recognize is_power_of_2 as a
	 * constant expression, so so much for that. */
	BUG_ON(!is_power_of_2(minalign));
	BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE));

	if (PGT_CACHE(shift))
		return; /* Already have a cache of this size */

	align = max_t(unsigned long, align, minalign);
	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
	new = kmem_cache_create(name, table_size, align, 0, ctor);
	PGT_CACHE(shift) = new;

	pr_debug("Allocated pgtable cache for order %d\n", shift);
}


void pgtable_cache_init(void)
{
	pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
	pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor);
	if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE))
		panic("Couldn't allocate pgtable caches");

	/* In all current configs, when the PUD index exists it's the
	 * same size as either the pgd or pmd index.  Verify that the
	 * initialization above has also created a PUD cache.  This
	 * will need re-examiniation if we add new possibilities for
	 * the pagetable layout. */
	BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE));
}

#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
 * Given an address within the vmemmap, determine the pfn of the page that
 * represents the start of the section it is within.  Note that we have to
 * do this by hand as the proffered address may not be correctly aligned.
 * Subtraction of non-aligned pointers produces undefined results.
 */
static unsigned long __meminit vmemmap_section_start(unsigned long page)
{
	unsigned long offset = page - ((unsigned long)(vmemmap));

	/* Return the pfn of the start of the section. */
	return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
}

/*
 * Check if this vmemmap page is already initialised.  If any section
 * which overlaps this vmemmap page is initialised then this page is
 * initialised already.
 */
static int __meminit vmemmap_populated(unsigned long start, int page_size)
{
	unsigned long end = start + page_size;

	for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
		if (pfn_valid(vmemmap_section_start(start)))
			return 1;

	return 0;
}

/* On hash-based CPUs, the vmemmap is bolted in the hash table.
 *
 * On Book3E CPUs, the vmemmap is currently mapped in the top half of
 * the vmalloc space using normal page tables, though the size of
 * pages encoded in the PTEs can be different
 */

#ifdef CONFIG_PPC_BOOK3E
static void __meminit vmemmap_create_mapping(unsigned long start,
					     unsigned long page_size,
					     unsigned long phys)
{
	/* Create a PTE encoding without page size */
	unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
		_PAGE_KERNEL_RW;

	/* PTEs only contain page size encodings up to 32M */
	BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);

	/* Encode the size in the PTE */
	flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;

	/* For each PTE for that area, map things. Note that we don't
	 * increment phys because all PTEs are of the large size and
	 * thus must have the low bits clear
	 */
	for (i = 0; i < page_size; i += PAGE_SIZE)
		BUG_ON(map_kernel_page(start + i, phys, flags));
}
#else /* CONFIG_PPC_BOOK3E */
static void __meminit vmemmap_create_mapping(unsigned long start,
					     unsigned long page_size,
					     unsigned long phys)
{
	int  mapped = htab_bolt_mapping(start, start + page_size, phys,
					PAGE_KERNEL, mmu_vmemmap_psize,
					mmu_kernel_ssize);
	BUG_ON(mapped < 0);
}
#endif /* CONFIG_PPC_BOOK3E */

struct vmemmap_backing *vmemmap_list;

static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
{
	static struct vmemmap_backing *next;
	static int num_left;

	/* allocate a page when required and hand out chunks */
	if (!next || !num_left) {
		next = vmemmap_alloc_block(PAGE_SIZE, node);
		if (unlikely(!next)) {
			WARN_ON(1);
			return NULL;
		}
		num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
	}

	num_left--;

	return next++;
}

static __meminit void vmemmap_list_populate(unsigned long phys,
					    unsigned long start,
					    int node)
{
	struct vmemmap_backing *vmem_back;

	vmem_back = vmemmap_list_alloc(node);
	if (unlikely(!vmem_back)) {
		WARN_ON(1);
		return;
	}

	vmem_back->phys = phys;
	vmem_back->virt_addr = start;
	vmem_back->list = vmemmap_list;

	vmemmap_list = vmem_back;
}

int __meminit vmemmap_populate(struct page *start_page,
			       unsigned long nr_pages, int node)
{
	unsigned long start = (unsigned long)start_page;
	unsigned long end = (unsigned long)(start_page + nr_pages);
	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;

	/* Align to the page size of the linear mapping. */
	start = _ALIGN_DOWN(start, page_size);

	pr_debug("vmemmap_populate page %p, %ld pages, node %d\n",
		 start_page, nr_pages, node);
	pr_debug(" -> map %lx..%lx\n", start, end);

	for (; start < end; start += page_size) {
		void *p;

		if (vmemmap_populated(start, page_size))
			continue;

		p = vmemmap_alloc_block(page_size, node);
		if (!p)
			return -ENOMEM;

		vmemmap_list_populate(__pa(p), start, node);

		pr_debug("      * %016lx..%016lx allocated at %p\n",
			 start, start + page_size, p);

		vmemmap_create_mapping(start, page_size, __pa(p));
	}

	return 0;
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */