summaryrefslogtreecommitdiff
path: root/arch/powerpc/mm/init_64.c
blob: db7d4e09215767c8f0389a0519231f1f668d7557 (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
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
/*
 *  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/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 <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <linux/memremap.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 <linux/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_BOOK3S_64
#if H_PGTABLE_RANGE > USER_VSID_RANGE
#warning Limited user VSID range means pagetable space is wasted
#endif
#endif /* CONFIG_PPC_BOOK3S_64 */

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

#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;
	start = (unsigned long)(pfn_to_page(vmemmap_section_start(start)));

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

	return 0;
}

/*
 * vmemmap virtual address space management does not have a traditonal page
 * table to track which virtual struct pages are backed by physical mapping.
 * The virtual to physical mappings are tracked in a simple linked list
 * format. 'vmemmap_list' maintains the entire vmemmap physical mapping at
 * all times where as the 'next' list maintains the available
 * vmemmap_backing structures which have been deleted from the
 * 'vmemmap_global' list during system runtime (memory hotplug remove
 * operation). The freed 'vmemmap_backing' structures are reused later when
 * new requests come in without allocating fresh memory. This pointer also
 * tracks the allocated 'vmemmap_backing' structures as we allocate one
 * full page memory at a time when we dont have any.
 */
struct vmemmap_backing *vmemmap_list;
static struct vmemmap_backing *next;

/*
 * The same pointer 'next' tracks individual chunks inside the allocated
 * full page during the boot time and again tracks the freeed nodes during
 * runtime. It is racy but it does not happen as they are separated by the
 * boot process. Will create problem if some how we have memory hotplug
 * operation during boot !!
 */
static int num_left;
static int num_freed;

static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
{
	struct vmemmap_backing *vmem_back;
	/* get from freed entries first */
	if (num_freed) {
		num_freed--;
		vmem_back = next;
		next = next->list;

		return vmem_back;
	}

	/* allocate a page when required and hand out chunks */
	if (!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(unsigned long start, unsigned long end, int node,
		struct vmem_altmap *altmap)
{
	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 %lx..%lx, node %d\n", start, end, node);

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

		if (vmemmap_populated(start, page_size))
			continue;

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

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

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

		rc = vmemmap_create_mapping(start, page_size, __pa(p));
		if (rc < 0) {
			pr_warning(
				"vmemmap_populate: Unable to create vmemmap mapping: %d\n",
				rc);
			return -EFAULT;
		}
	}

	return 0;
}

#ifdef CONFIG_MEMORY_HOTPLUG
static unsigned long vmemmap_list_free(unsigned long start)
{
	struct vmemmap_backing *vmem_back, *vmem_back_prev;

	vmem_back_prev = vmem_back = vmemmap_list;

	/* look for it with prev pointer recorded */
	for (; vmem_back; vmem_back = vmem_back->list) {
		if (vmem_back->virt_addr == start)
			break;
		vmem_back_prev = vmem_back;
	}

	if (unlikely(!vmem_back)) {
		WARN_ON(1);
		return 0;
	}

	/* remove it from vmemmap_list */
	if (vmem_back == vmemmap_list) /* remove head */
		vmemmap_list = vmem_back->list;
	else
		vmem_back_prev->list = vmem_back->list;

	/* next point to this freed entry */
	vmem_back->list = next;
	next = vmem_back;
	num_freed++;

	return vmem_back->phys;
}

void __ref vmemmap_free(unsigned long start, unsigned long end,
		struct vmem_altmap *altmap)
{
	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
	unsigned long page_order = get_order(page_size);

	start = _ALIGN_DOWN(start, page_size);

	pr_debug("vmemmap_free %lx...%lx\n", start, end);

	for (; start < end; start += page_size) {
		unsigned long nr_pages, addr;
		struct page *section_base;
		struct page *page;

		/*
		 * the section has already be marked as invalid, so
		 * vmemmap_populated() true means some other sections still
		 * in this page, so skip it.
		 */
		if (vmemmap_populated(start, page_size))
			continue;

		addr = vmemmap_list_free(start);
		if (!addr)
			continue;

		page = pfn_to_page(addr >> PAGE_SHIFT);
		section_base = pfn_to_page(vmemmap_section_start(start));
		nr_pages = 1 << page_order;

		if (altmap) {
			vmem_altmap_free(altmap, nr_pages);
		} else if (PageReserved(page)) {
			/* allocated from bootmem */
			if (page_size < PAGE_SIZE) {
				/*
				 * this shouldn't happen, but if it is
				 * the case, leave the memory there
				 */
				WARN_ON_ONCE(1);
			} else {
				while (nr_pages--)
					free_reserved_page(page++);
			}
		} else {
			free_pages((unsigned long)(__va(addr)), page_order);
		}

		vmemmap_remove_mapping(start, page_size);
	}
}
#endif
void register_page_bootmem_memmap(unsigned long section_nr,
				  struct page *start_page, unsigned long size)
{
}

/*
 * We do not have access to the sparsemem vmemmap, so we fallback to
 * walking the list of sparsemem blocks which we already maintain for
 * the sake of crashdump. In the long run, we might want to maintain
 * a tree if performance of that linear walk becomes a problem.
 *
 * realmode_pfn_to_page functions can fail due to:
 * 1) As real sparsemem blocks do not lay in RAM continously (they
 * are in virtual address space which is not available in the real mode),
 * the requested page struct can be split between blocks so get_page/put_page
 * may fail.
 * 2) When huge pages are used, the get_page/put_page API will fail
 * in real mode as the linked addresses in the page struct are virtual
 * too.
 */
struct page *realmode_pfn_to_page(unsigned long pfn)
{
	struct vmemmap_backing *vmem_back;
	struct page *page;
	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
	unsigned long pg_va = (unsigned long) pfn_to_page(pfn);

	for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) {
		if (pg_va < vmem_back->virt_addr)
			continue;

		/* After vmemmap_list entry free is possible, need check all */
		if ((pg_va + sizeof(struct page)) <=
				(vmem_back->virt_addr + page_size)) {
			page = (struct page *) (vmem_back->phys + pg_va -
				vmem_back->virt_addr);
			return page;
		}
	}

	/* Probably that page struct is split between real pages */
	return NULL;
}
EXPORT_SYMBOL_GPL(realmode_pfn_to_page);

#else

struct page *realmode_pfn_to_page(unsigned long pfn)
{
	struct page *page = pfn_to_page(pfn);
	return page;
}
EXPORT_SYMBOL_GPL(realmode_pfn_to_page);

#endif /* CONFIG_SPARSEMEM_VMEMMAP */

#ifdef CONFIG_PPC_BOOK3S_64
static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);

static int __init parse_disable_radix(char *p)
{
	bool val;

	if (strlen(p) == 0)
		val = true;
	else if (kstrtobool(p, &val))
		return -EINVAL;

	disable_radix = val;

	return 0;
}
early_param("disable_radix", parse_disable_radix);

/*
 * If we're running under a hypervisor, we need to check the contents of
 * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
 * radix.  If not, we clear the radix feature bit so we fall back to hash.
 */
static void __init early_check_vec5(void)
{
	unsigned long root, chosen;
	int size;
	const u8 *vec5;
	u8 mmu_supported;

	root = of_get_flat_dt_root();
	chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
	if (chosen == -FDT_ERR_NOTFOUND) {
		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
		return;
	}
	vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
	if (!vec5) {
		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
		return;
	}
	if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
		return;
	}

	/* Check for supported configuration */
	mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
			OV5_FEAT(OV5_MMU_SUPPORT);
	if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
		/* Hypervisor only supports radix - check enabled && GTSE */
		if (!early_radix_enabled()) {
			pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
		}
		if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
						OV5_FEAT(OV5_RADIX_GTSE))) {
			pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n");
		}
		/* Do radix anyway - the hypervisor said we had to */
		cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
	} else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
		/* Hypervisor only supports hash - disable radix */
		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
	}
}

void __init mmu_early_init_devtree(void)
{
	/* Disable radix mode based on kernel command line. */
	if (disable_radix)
		cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;

	/*
	 * Check /chosen/ibm,architecture-vec-5 if running as a guest.
	 * When running bare-metal, we can use radix if we like
	 * even though the ibm,architecture-vec-5 property created by
	 * skiboot doesn't have the necessary bits set.
	 */
	if (!(mfmsr() & MSR_HV))
		early_check_vec5();

	if (early_radix_enabled())
		radix__early_init_devtree();
	else
		hash__early_init_devtree();
}
#endif /* CONFIG_PPC_BOOK3S_64 */