Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PowerPC version
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 *
6 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
7 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
8 * Copyright (C) 1996 Paul Mackerras
9 *
10 * Derived from "arch/i386/mm/init.c"
11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
12 *
13 * Dave Engebretsen <engebret@us.ibm.com>
14 * Rework for PPC64 port.
15 */
16
17#undef DEBUG
18
19#include <linux/signal.h>
20#include <linux/sched.h>
21#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/string.h>
24#include <linux/types.h>
25#include <linux/mman.h>
26#include <linux/mm.h>
27#include <linux/swap.h>
28#include <linux/stddef.h>
29#include <linux/vmalloc.h>
30#include <linux/init.h>
31#include <linux/delay.h>
32#include <linux/highmem.h>
33#include <linux/idr.h>
34#include <linux/nodemask.h>
35#include <linux/module.h>
36#include <linux/poison.h>
37#include <linux/memblock.h>
38#include <linux/hugetlb.h>
39#include <linux/slab.h>
40#include <linux/of_fdt.h>
41#include <linux/libfdt.h>
42#include <linux/memremap.h>
43#include <linux/memory.h>
44
45#include <asm/pgalloc.h>
46#include <asm/page.h>
47#include <asm/prom.h>
48#include <asm/rtas.h>
49#include <asm/io.h>
50#include <asm/mmu_context.h>
51#include <asm/mmu.h>
52#include <linux/uaccess.h>
53#include <asm/smp.h>
54#include <asm/machdep.h>
55#include <asm/tlb.h>
56#include <asm/eeh.h>
57#include <asm/processor.h>
58#include <asm/mmzone.h>
59#include <asm/cputable.h>
60#include <asm/sections.h>
61#include <asm/iommu.h>
62#include <asm/vdso.h>
63#include <asm/hugetlb.h>
64
65#include <mm/mmu_decl.h>
66
67#ifdef CONFIG_SPARSEMEM_VMEMMAP
68/*
69 * Given an address within the vmemmap, determine the page that
70 * represents the start of the subsection it is within. Note that we have to
71 * do this by hand as the proffered address may not be correctly aligned.
72 * Subtraction of non-aligned pointers produces undefined results.
73 */
74static struct page * __meminit vmemmap_subsection_start(unsigned long vmemmap_addr)
75{
76 unsigned long start_pfn;
77 unsigned long offset = vmemmap_addr - ((unsigned long)(vmemmap));
78
79 /* Return the pfn of the start of the section. */
80 start_pfn = (offset / sizeof(struct page)) & PAGE_SUBSECTION_MASK;
81 return pfn_to_page(start_pfn);
82}
83
84/*
85 * Since memory is added in sub-section chunks, before creating a new vmemmap
86 * mapping, the kernel should check whether there is an existing memmap mapping
87 * covering the new subsection added. This is needed because kernel can map
88 * vmemmap area using 16MB pages which will cover a memory range of 16G. Such
89 * a range covers multiple subsections (2M)
90 *
91 * If any subsection in the 16G range mapped by vmemmap is valid we consider the
92 * vmemmap populated (There is a page table entry already present). We can't do
93 * a page table lookup here because with the hash translation we don't keep
94 * vmemmap details in linux page table.
95 */
96int __meminit vmemmap_populated(unsigned long vmemmap_addr, int vmemmap_map_size)
97{
98 struct page *start;
99 unsigned long vmemmap_end = vmemmap_addr + vmemmap_map_size;
100 start = vmemmap_subsection_start(vmemmap_addr);
101
102 for (; (unsigned long)start < vmemmap_end; start += PAGES_PER_SUBSECTION)
103 /*
104 * pfn valid check here is intended to really check
105 * whether we have any subsection already initialized
106 * in this range.
107 */
108 if (pfn_valid(page_to_pfn(start)))
109 return 1;
110
111 return 0;
112}
113
114/*
115 * vmemmap virtual address space management does not have a traditional page
116 * table to track which virtual struct pages are backed by physical mapping.
117 * The virtual to physical mappings are tracked in a simple linked list
118 * format. 'vmemmap_list' maintains the entire vmemmap physical mapping at
119 * all times where as the 'next' list maintains the available
120 * vmemmap_backing structures which have been deleted from the
121 * 'vmemmap_global' list during system runtime (memory hotplug remove
122 * operation). The freed 'vmemmap_backing' structures are reused later when
123 * new requests come in without allocating fresh memory. This pointer also
124 * tracks the allocated 'vmemmap_backing' structures as we allocate one
125 * full page memory at a time when we dont have any.
126 */
127struct vmemmap_backing *vmemmap_list;
128static struct vmemmap_backing *next;
129
130/*
131 * The same pointer 'next' tracks individual chunks inside the allocated
132 * full page during the boot time and again tracks the freed nodes during
133 * runtime. It is racy but it does not happen as they are separated by the
134 * boot process. Will create problem if some how we have memory hotplug
135 * operation during boot !!
136 */
137static int num_left;
138static int num_freed;
139
140static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
141{
142 struct vmemmap_backing *vmem_back;
143 /* get from freed entries first */
144 if (num_freed) {
145 num_freed--;
146 vmem_back = next;
147 next = next->list;
148
149 return vmem_back;
150 }
151
152 /* allocate a page when required and hand out chunks */
153 if (!num_left) {
154 next = vmemmap_alloc_block(PAGE_SIZE, node);
155 if (unlikely(!next)) {
156 WARN_ON(1);
157 return NULL;
158 }
159 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
160 }
161
162 num_left--;
163
164 return next++;
165}
166
167static __meminit int vmemmap_list_populate(unsigned long phys,
168 unsigned long start,
169 int node)
170{
171 struct vmemmap_backing *vmem_back;
172
173 vmem_back = vmemmap_list_alloc(node);
174 if (unlikely(!vmem_back)) {
175 pr_debug("vmemap list allocation failed\n");
176 return -ENOMEM;
177 }
178
179 vmem_back->phys = phys;
180 vmem_back->virt_addr = start;
181 vmem_back->list = vmemmap_list;
182
183 vmemmap_list = vmem_back;
184 return 0;
185}
186
187bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start,
188 unsigned long page_size)
189{
190 unsigned long nr_pfn = page_size / sizeof(struct page);
191 unsigned long start_pfn = page_to_pfn((struct page *)start);
192
193 if ((start_pfn + nr_pfn - 1) > altmap->end_pfn)
194 return true;
195
196 if (start_pfn < altmap->base_pfn)
197 return true;
198
199 return false;
200}
201
202static int __meminit __vmemmap_populate(unsigned long start, unsigned long end, int node,
203 struct vmem_altmap *altmap)
204{
205 bool altmap_alloc;
206 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
207
208 /* Align to the page size of the linear mapping. */
209 start = ALIGN_DOWN(start, page_size);
210
211 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
212
213 for (; start < end; start += page_size) {
214 void *p = NULL;
215 int rc;
216
217 /*
218 * This vmemmap range is backing different subsections. If any
219 * of that subsection is marked valid, that means we already
220 * have initialized a page table covering this range and hence
221 * the vmemmap range is populated.
222 */
223 if (vmemmap_populated(start, page_size))
224 continue;
225
226 /*
227 * Allocate from the altmap first if we have one. This may
228 * fail due to alignment issues when using 16MB hugepages, so
229 * fall back to system memory if the altmap allocation fail.
230 */
231 if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
232 p = vmemmap_alloc_block_buf(page_size, node, altmap);
233 if (!p)
234 pr_debug("altmap block allocation failed, falling back to system memory");
235 else
236 altmap_alloc = true;
237 }
238 if (!p) {
239 p = vmemmap_alloc_block_buf(page_size, node, NULL);
240 altmap_alloc = false;
241 }
242 if (!p)
243 return -ENOMEM;
244
245 if (vmemmap_list_populate(__pa(p), start, node)) {
246 /*
247 * If we don't populate vmemap list, we don't have
248 * the ability to free the allocated vmemmap
249 * pages in section_deactivate. Hence free them
250 * here.
251 */
252 int nr_pfns = page_size >> PAGE_SHIFT;
253 unsigned long page_order = get_order(page_size);
254
255 if (altmap_alloc)
256 vmem_altmap_free(altmap, nr_pfns);
257 else
258 free_pages((unsigned long)p, page_order);
259 return -ENOMEM;
260 }
261
262 pr_debug(" * %016lx..%016lx allocated at %p\n",
263 start, start + page_size, p);
264
265 rc = vmemmap_create_mapping(start, page_size, __pa(p));
266 if (rc < 0) {
267 pr_warn("%s: Unable to create vmemmap mapping: %d\n",
268 __func__, rc);
269 return -EFAULT;
270 }
271 }
272
273 return 0;
274}
275
276int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
277 struct vmem_altmap *altmap)
278{
279
280#ifdef CONFIG_PPC_BOOK3S_64
281 if (radix_enabled())
282 return radix__vmemmap_populate(start, end, node, altmap);
283#endif
284
285 return __vmemmap_populate(start, end, node, altmap);
286}
287
288#ifdef CONFIG_MEMORY_HOTPLUG
289static unsigned long vmemmap_list_free(unsigned long start)
290{
291 struct vmemmap_backing *vmem_back, *vmem_back_prev;
292
293 vmem_back_prev = vmem_back = vmemmap_list;
294
295 /* look for it with prev pointer recorded */
296 for (; vmem_back; vmem_back = vmem_back->list) {
297 if (vmem_back->virt_addr == start)
298 break;
299 vmem_back_prev = vmem_back;
300 }
301
302 if (unlikely(!vmem_back))
303 return 0;
304
305 /* remove it from vmemmap_list */
306 if (vmem_back == vmemmap_list) /* remove head */
307 vmemmap_list = vmem_back->list;
308 else
309 vmem_back_prev->list = vmem_back->list;
310
311 /* next point to this freed entry */
312 vmem_back->list = next;
313 next = vmem_back;
314 num_freed++;
315
316 return vmem_back->phys;
317}
318
319static void __ref __vmemmap_free(unsigned long start, unsigned long end,
320 struct vmem_altmap *altmap)
321{
322 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
323 unsigned long page_order = get_order(page_size);
324 unsigned long alt_start = ~0, alt_end = ~0;
325 unsigned long base_pfn;
326
327 start = ALIGN_DOWN(start, page_size);
328 if (altmap) {
329 alt_start = altmap->base_pfn;
330 alt_end = altmap->base_pfn + altmap->reserve + altmap->free;
331 }
332
333 pr_debug("vmemmap_free %lx...%lx\n", start, end);
334
335 for (; start < end; start += page_size) {
336 unsigned long nr_pages, addr;
337 struct page *page;
338
339 /*
340 * We have already marked the subsection we are trying to remove
341 * invalid. So if we want to remove the vmemmap range, we
342 * need to make sure there is no subsection marked valid
343 * in this range.
344 */
345 if (vmemmap_populated(start, page_size))
346 continue;
347
348 addr = vmemmap_list_free(start);
349 if (!addr)
350 continue;
351
352 page = pfn_to_page(addr >> PAGE_SHIFT);
353 nr_pages = 1 << page_order;
354 base_pfn = PHYS_PFN(addr);
355
356 if (base_pfn >= alt_start && base_pfn < alt_end) {
357 vmem_altmap_free(altmap, nr_pages);
358 } else if (PageReserved(page)) {
359 /* allocated from bootmem */
360 if (page_size < PAGE_SIZE) {
361 /*
362 * this shouldn't happen, but if it is
363 * the case, leave the memory there
364 */
365 WARN_ON_ONCE(1);
366 } else {
367 while (nr_pages--)
368 free_reserved_page(page++);
369 }
370 } else {
371 free_pages((unsigned long)(__va(addr)), page_order);
372 }
373
374 vmemmap_remove_mapping(start, page_size);
375 }
376}
377
378void __ref vmemmap_free(unsigned long start, unsigned long end,
379 struct vmem_altmap *altmap)
380{
381#ifdef CONFIG_PPC_BOOK3S_64
382 if (radix_enabled())
383 return radix__vmemmap_free(start, end, altmap);
384#endif
385 return __vmemmap_free(start, end, altmap);
386}
387
388#endif
389void register_page_bootmem_memmap(unsigned long section_nr,
390 struct page *start_page, unsigned long size)
391{
392}
393
394#endif /* CONFIG_SPARSEMEM_VMEMMAP */
395
396#ifdef CONFIG_PPC_BOOK3S_64
397unsigned int mmu_lpid_bits;
398#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
399EXPORT_SYMBOL_GPL(mmu_lpid_bits);
400#endif
401unsigned int mmu_pid_bits;
402
403static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
404
405static int __init parse_disable_radix(char *p)
406{
407 bool val;
408
409 if (!p)
410 val = true;
411 else if (kstrtobool(p, &val))
412 return -EINVAL;
413
414 disable_radix = val;
415
416 return 0;
417}
418early_param("disable_radix", parse_disable_radix);
419
420/*
421 * If we're running under a hypervisor, we need to check the contents of
422 * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
423 * radix. If not, we clear the radix feature bit so we fall back to hash.
424 */
425static void __init early_check_vec5(void)
426{
427 unsigned long root, chosen;
428 int size;
429 const u8 *vec5;
430 u8 mmu_supported;
431
432 root = of_get_flat_dt_root();
433 chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
434 if (chosen == -FDT_ERR_NOTFOUND) {
435 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
436 return;
437 }
438 vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
439 if (!vec5) {
440 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
441 return;
442 }
443 if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
444 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
445 return;
446 }
447
448 /* Check for supported configuration */
449 mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
450 OV5_FEAT(OV5_MMU_SUPPORT);
451 if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
452 /* Hypervisor only supports radix - check enabled && GTSE */
453 if (!early_radix_enabled()) {
454 pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
455 }
456 if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
457 OV5_FEAT(OV5_RADIX_GTSE))) {
458 cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
459 } else
460 cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
461 /* Do radix anyway - the hypervisor said we had to */
462 cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
463 } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
464 /* Hypervisor only supports hash - disable radix */
465 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
466 cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
467 }
468}
469
470static int __init dt_scan_mmu_pid_width(unsigned long node,
471 const char *uname, int depth,
472 void *data)
473{
474 int size = 0;
475 const __be32 *prop;
476 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
477
478 /* We are scanning "cpu" nodes only */
479 if (type == NULL || strcmp(type, "cpu") != 0)
480 return 0;
481
482 /* Find MMU LPID, PID register size */
483 prop = of_get_flat_dt_prop(node, "ibm,mmu-lpid-bits", &size);
484 if (prop && size == 4)
485 mmu_lpid_bits = be32_to_cpup(prop);
486
487 prop = of_get_flat_dt_prop(node, "ibm,mmu-pid-bits", &size);
488 if (prop && size == 4)
489 mmu_pid_bits = be32_to_cpup(prop);
490
491 if (!mmu_pid_bits && !mmu_lpid_bits)
492 return 0;
493
494 return 1;
495}
496
497/*
498 * Outside hotplug the kernel uses this value to map the kernel direct map
499 * with radix. To be compatible with older kernels, let's keep this value
500 * as 16M which is also SECTION_SIZE with SPARSEMEM. We can ideally map
501 * things with 1GB size in the case where we don't support hotplug.
502 */
503#ifndef CONFIG_MEMORY_HOTPLUG
504#define DEFAULT_MEMORY_BLOCK_SIZE SZ_16M
505#else
506#define DEFAULT_MEMORY_BLOCK_SIZE MIN_MEMORY_BLOCK_SIZE
507#endif
508
509static void update_memory_block_size(unsigned long *block_size, unsigned long mem_size)
510{
511 unsigned long min_memory_block_size = DEFAULT_MEMORY_BLOCK_SIZE;
512
513 for (; *block_size > min_memory_block_size; *block_size >>= 2) {
514 if ((mem_size & *block_size) == 0)
515 break;
516 }
517}
518
519static int __init probe_memory_block_size(unsigned long node, const char *uname, int
520 depth, void *data)
521{
522 const char *type;
523 unsigned long *block_size = (unsigned long *)data;
524 const __be32 *reg, *endp;
525 int l;
526
527 if (depth != 1)
528 return 0;
529 /*
530 * If we have dynamic-reconfiguration-memory node, use the
531 * lmb value.
532 */
533 if (strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0) {
534
535 const __be32 *prop;
536
537 prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
538
539 if (!prop || l < dt_root_size_cells * sizeof(__be32))
540 /*
541 * Nothing in the device tree
542 */
543 *block_size = DEFAULT_MEMORY_BLOCK_SIZE;
544 else
545 *block_size = of_read_number(prop, dt_root_size_cells);
546 /*
547 * We have found the final value. Don't probe further.
548 */
549 return 1;
550 }
551 /*
552 * Find all the device tree nodes of memory type and make sure
553 * the area can be mapped using the memory block size value
554 * we end up using. We start with 1G value and keep reducing
555 * it such that we can map the entire area using memory_block_size.
556 * This will be used on powernv and older pseries that don't
557 * have ibm,lmb-size node.
558 * For ex: with P5 we can end up with
559 * memory@0 -> 128MB
560 * memory@128M -> 64M
561 * This will end up using 64MB memory block size value.
562 */
563 type = of_get_flat_dt_prop(node, "device_type", NULL);
564 if (type == NULL || strcmp(type, "memory") != 0)
565 return 0;
566
567 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
568 if (!reg)
569 reg = of_get_flat_dt_prop(node, "reg", &l);
570 if (!reg)
571 return 0;
572
573 endp = reg + (l / sizeof(__be32));
574 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
575 const char *compatible;
576 u64 size;
577
578 dt_mem_next_cell(dt_root_addr_cells, ®);
579 size = dt_mem_next_cell(dt_root_size_cells, ®);
580
581 if (size) {
582 update_memory_block_size(block_size, size);
583 continue;
584 }
585 /*
586 * ibm,coherent-device-memory with linux,usable-memory = 0
587 * Force 256MiB block size. Work around for GPUs on P9 PowerNV
588 * linux,usable-memory == 0 implies driver managed memory and
589 * we can't use large memory block size due to hotplug/unplug
590 * limitations.
591 */
592 compatible = of_get_flat_dt_prop(node, "compatible", NULL);
593 if (compatible && !strcmp(compatible, "ibm,coherent-device-memory")) {
594 if (*block_size > SZ_256M)
595 *block_size = SZ_256M;
596 /*
597 * We keep 256M as the upper limit with GPU present.
598 */
599 return 0;
600 }
601 }
602 /* continue looking for other memory device types */
603 return 0;
604}
605
606/*
607 * start with 1G memory block size. Early init will
608 * fix this with correct value.
609 */
610unsigned long memory_block_size __ro_after_init = 1UL << 30;
611static void __init early_init_memory_block_size(void)
612{
613 /*
614 * We need to do memory_block_size probe early so that
615 * radix__early_init_mmu() can use this as limit for
616 * mapping page size.
617 */
618 of_scan_flat_dt(probe_memory_block_size, &memory_block_size);
619}
620
621void __init mmu_early_init_devtree(void)
622{
623 bool hvmode = !!(mfmsr() & MSR_HV);
624
625 /* Disable radix mode based on kernel command line. */
626 if (disable_radix) {
627 if (IS_ENABLED(CONFIG_PPC_64S_HASH_MMU))
628 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
629 else
630 pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
631 }
632
633 of_scan_flat_dt(dt_scan_mmu_pid_width, NULL);
634 if (hvmode && !mmu_lpid_bits) {
635 if (early_cpu_has_feature(CPU_FTR_ARCH_207S))
636 mmu_lpid_bits = 12; /* POWER8-10 */
637 else
638 mmu_lpid_bits = 10; /* POWER7 */
639 }
640 if (!mmu_pid_bits) {
641 if (early_cpu_has_feature(CPU_FTR_ARCH_300))
642 mmu_pid_bits = 20; /* POWER9-10 */
643 }
644
645 /*
646 * Check /chosen/ibm,architecture-vec-5 if running as a guest.
647 * When running bare-metal, we can use radix if we like
648 * even though the ibm,architecture-vec-5 property created by
649 * skiboot doesn't have the necessary bits set.
650 */
651 if (!hvmode)
652 early_check_vec5();
653
654 early_init_memory_block_size();
655
656 if (early_radix_enabled()) {
657 radix__early_init_devtree();
658
659 /*
660 * We have finalized the translation we are going to use by now.
661 * Radix mode is not limited by RMA / VRMA addressing.
662 * Hence don't limit memblock allocations.
663 */
664 ppc64_rma_size = ULONG_MAX;
665 memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
666 } else
667 hash__early_init_devtree();
668
669 if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
670 hugetlbpage_init_defaultsize();
671
672 if (!(cur_cpu_spec->mmu_features & MMU_FTR_HPTE_TABLE) &&
673 !(cur_cpu_spec->mmu_features & MMU_FTR_TYPE_RADIX))
674 panic("kernel does not support any MMU type offered by platform");
675}
676#endif /* CONFIG_PPC_BOOK3S_64 */
1/*
2 * PowerPC version
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
6 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
7 * Copyright (C) 1996 Paul Mackerras
8 *
9 * Derived from "arch/i386/mm/init.c"
10 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
11 *
12 * Dave Engebretsen <engebret@us.ibm.com>
13 * Rework for PPC64 port.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 *
20 */
21
22#undef DEBUG
23
24#include <linux/signal.h>
25#include <linux/sched.h>
26#include <linux/kernel.h>
27#include <linux/errno.h>
28#include <linux/string.h>
29#include <linux/types.h>
30#include <linux/mman.h>
31#include <linux/mm.h>
32#include <linux/swap.h>
33#include <linux/stddef.h>
34#include <linux/vmalloc.h>
35#include <linux/init.h>
36#include <linux/delay.h>
37#include <linux/bootmem.h>
38#include <linux/highmem.h>
39#include <linux/idr.h>
40#include <linux/nodemask.h>
41#include <linux/module.h>
42#include <linux/poison.h>
43#include <linux/memblock.h>
44#include <linux/hugetlb.h>
45#include <linux/slab.h>
46
47#include <asm/pgalloc.h>
48#include <asm/page.h>
49#include <asm/prom.h>
50#include <asm/rtas.h>
51#include <asm/io.h>
52#include <asm/mmu_context.h>
53#include <asm/pgtable.h>
54#include <asm/mmu.h>
55#include <asm/uaccess.h>
56#include <asm/smp.h>
57#include <asm/machdep.h>
58#include <asm/tlb.h>
59#include <asm/eeh.h>
60#include <asm/processor.h>
61#include <asm/mmzone.h>
62#include <asm/cputable.h>
63#include <asm/sections.h>
64#include <asm/iommu.h>
65#include <asm/vdso.h>
66
67#include "mmu_decl.h"
68
69#ifdef CONFIG_PPC_STD_MMU_64
70#if PGTABLE_RANGE > USER_VSID_RANGE
71#warning Limited user VSID range means pagetable space is wasted
72#endif
73
74#if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE)
75#warning TASK_SIZE is smaller than it needs to be.
76#endif
77#endif /* CONFIG_PPC_STD_MMU_64 */
78
79phys_addr_t memstart_addr = ~0;
80EXPORT_SYMBOL_GPL(memstart_addr);
81phys_addr_t kernstart_addr;
82EXPORT_SYMBOL_GPL(kernstart_addr);
83
84static void pgd_ctor(void *addr)
85{
86 memset(addr, 0, PGD_TABLE_SIZE);
87}
88
89static void pmd_ctor(void *addr)
90{
91#ifdef CONFIG_TRANSPARENT_HUGEPAGE
92 memset(addr, 0, PMD_TABLE_SIZE * 2);
93#else
94 memset(addr, 0, PMD_TABLE_SIZE);
95#endif
96}
97
98struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
99
100/*
101 * Create a kmem_cache() for pagetables. This is not used for PTE
102 * pages - they're linked to struct page, come from the normal free
103 * pages pool and have a different entry size (see real_pte_t) to
104 * everything else. Caches created by this function are used for all
105 * the higher level pagetables, and for hugepage pagetables.
106 */
107void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
108{
109 char *name;
110 unsigned long table_size = sizeof(void *) << shift;
111 unsigned long align = table_size;
112
113 /* When batching pgtable pointers for RCU freeing, we store
114 * the index size in the low bits. Table alignment must be
115 * big enough to fit it.
116 *
117 * Likewise, hugeapge pagetable pointers contain a (different)
118 * shift value in the low bits. All tables must be aligned so
119 * as to leave enough 0 bits in the address to contain it. */
120 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
121 HUGEPD_SHIFT_MASK + 1);
122 struct kmem_cache *new;
123
124 /* It would be nice if this was a BUILD_BUG_ON(), but at the
125 * moment, gcc doesn't seem to recognize is_power_of_2 as a
126 * constant expression, so so much for that. */
127 BUG_ON(!is_power_of_2(minalign));
128 BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE));
129
130 if (PGT_CACHE(shift))
131 return; /* Already have a cache of this size */
132
133 align = max_t(unsigned long, align, minalign);
134 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
135 new = kmem_cache_create(name, table_size, align, 0, ctor);
136 pgtable_cache[shift - 1] = new;
137 pr_debug("Allocated pgtable cache for order %d\n", shift);
138}
139
140
141void pgtable_cache_init(void)
142{
143 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
144 pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor);
145 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_CACHE_INDEX))
146 panic("Couldn't allocate pgtable caches");
147 /* In all current configs, when the PUD index exists it's the
148 * same size as either the pgd or pmd index. Verify that the
149 * initialization above has also created a PUD cache. This
150 * will need re-examiniation if we add new possibilities for
151 * the pagetable layout. */
152 BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE));
153}
154
155#ifdef CONFIG_SPARSEMEM_VMEMMAP
156/*
157 * Given an address within the vmemmap, determine the pfn of the page that
158 * represents the start of the section it is within. Note that we have to
159 * do this by hand as the proffered address may not be correctly aligned.
160 * Subtraction of non-aligned pointers produces undefined results.
161 */
162static unsigned long __meminit vmemmap_section_start(unsigned long page)
163{
164 unsigned long offset = page - ((unsigned long)(vmemmap));
165
166 /* Return the pfn of the start of the section. */
167 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
168}
169
170/*
171 * Check if this vmemmap page is already initialised. If any section
172 * which overlaps this vmemmap page is initialised then this page is
173 * initialised already.
174 */
175static int __meminit vmemmap_populated(unsigned long start, int page_size)
176{
177 unsigned long end = start + page_size;
178
179 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
180 if (pfn_valid(vmemmap_section_start(start)))
181 return 1;
182
183 return 0;
184}
185
186/* On hash-based CPUs, the vmemmap is bolted in the hash table.
187 *
188 * On Book3E CPUs, the vmemmap is currently mapped in the top half of
189 * the vmalloc space using normal page tables, though the size of
190 * pages encoded in the PTEs can be different
191 */
192
193#ifdef CONFIG_PPC_BOOK3E
194static void __meminit vmemmap_create_mapping(unsigned long start,
195 unsigned long page_size,
196 unsigned long phys)
197{
198 /* Create a PTE encoding without page size */
199 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
200 _PAGE_KERNEL_RW;
201
202 /* PTEs only contain page size encodings up to 32M */
203 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
204
205 /* Encode the size in the PTE */
206 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
207
208 /* For each PTE for that area, map things. Note that we don't
209 * increment phys because all PTEs are of the large size and
210 * thus must have the low bits clear
211 */
212 for (i = 0; i < page_size; i += PAGE_SIZE)
213 BUG_ON(map_kernel_page(start + i, phys, flags));
214}
215#else /* CONFIG_PPC_BOOK3E */
216static void __meminit vmemmap_create_mapping(unsigned long start,
217 unsigned long page_size,
218 unsigned long phys)
219{
220 int mapped = htab_bolt_mapping(start, start + page_size, phys,
221 pgprot_val(PAGE_KERNEL),
222 mmu_vmemmap_psize,
223 mmu_kernel_ssize);
224 BUG_ON(mapped < 0);
225}
226#endif /* CONFIG_PPC_BOOK3E */
227
228struct vmemmap_backing *vmemmap_list;
229
230static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
231{
232 static struct vmemmap_backing *next;
233 static int num_left;
234
235 /* allocate a page when required and hand out chunks */
236 if (!next || !num_left) {
237 next = vmemmap_alloc_block(PAGE_SIZE, node);
238 if (unlikely(!next)) {
239 WARN_ON(1);
240 return NULL;
241 }
242 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
243 }
244
245 num_left--;
246
247 return next++;
248}
249
250static __meminit void vmemmap_list_populate(unsigned long phys,
251 unsigned long start,
252 int node)
253{
254 struct vmemmap_backing *vmem_back;
255
256 vmem_back = vmemmap_list_alloc(node);
257 if (unlikely(!vmem_back)) {
258 WARN_ON(1);
259 return;
260 }
261
262 vmem_back->phys = phys;
263 vmem_back->virt_addr = start;
264 vmem_back->list = vmemmap_list;
265
266 vmemmap_list = vmem_back;
267}
268
269int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
270{
271 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
272
273 /* Align to the page size of the linear mapping. */
274 start = _ALIGN_DOWN(start, page_size);
275
276 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
277
278 for (; start < end; start += page_size) {
279 void *p;
280
281 if (vmemmap_populated(start, page_size))
282 continue;
283
284 p = vmemmap_alloc_block(page_size, node);
285 if (!p)
286 return -ENOMEM;
287
288 vmemmap_list_populate(__pa(p), start, node);
289
290 pr_debug(" * %016lx..%016lx allocated at %p\n",
291 start, start + page_size, p);
292
293 vmemmap_create_mapping(start, page_size, __pa(p));
294 }
295
296 return 0;
297}
298
299void vmemmap_free(unsigned long start, unsigned long end)
300{
301}
302
303void register_page_bootmem_memmap(unsigned long section_nr,
304 struct page *start_page, unsigned long size)
305{
306}
307
308/*
309 * We do not have access to the sparsemem vmemmap, so we fallback to
310 * walking the list of sparsemem blocks which we already maintain for
311 * the sake of crashdump. In the long run, we might want to maintain
312 * a tree if performance of that linear walk becomes a problem.
313 *
314 * realmode_pfn_to_page functions can fail due to:
315 * 1) As real sparsemem blocks do not lay in RAM continously (they
316 * are in virtual address space which is not available in the real mode),
317 * the requested page struct can be split between blocks so get_page/put_page
318 * may fail.
319 * 2) When huge pages are used, the get_page/put_page API will fail
320 * in real mode as the linked addresses in the page struct are virtual
321 * too.
322 */
323struct page *realmode_pfn_to_page(unsigned long pfn)
324{
325 struct vmemmap_backing *vmem_back;
326 struct page *page;
327 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
328 unsigned long pg_va = (unsigned long) pfn_to_page(pfn);
329
330 for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) {
331 if (pg_va < vmem_back->virt_addr)
332 continue;
333
334 /* Check that page struct is not split between real pages */
335 if ((pg_va + sizeof(struct page)) >
336 (vmem_back->virt_addr + page_size))
337 return NULL;
338
339 page = (struct page *) (vmem_back->phys + pg_va -
340 vmem_back->virt_addr);
341 return page;
342 }
343
344 return NULL;
345}
346EXPORT_SYMBOL_GPL(realmode_pfn_to_page);
347
348#elif defined(CONFIG_FLATMEM)
349
350struct page *realmode_pfn_to_page(unsigned long pfn)
351{
352 struct page *page = pfn_to_page(pfn);
353 return page;
354}
355EXPORT_SYMBOL_GPL(realmode_pfn_to_page);
356
357#endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */