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1/*
2 * Copyright (C) 1995 Linus Torvalds
3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation, version 2.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
12 * NON INFRINGEMENT. See the GNU General Public License for
13 * more details.
14 */
15
16#include <linux/module.h>
17#include <linux/signal.h>
18#include <linux/sched.h>
19#include <linux/kernel.h>
20#include <linux/errno.h>
21#include <linux/string.h>
22#include <linux/types.h>
23#include <linux/ptrace.h>
24#include <linux/mman.h>
25#include <linux/mm.h>
26#include <linux/hugetlb.h>
27#include <linux/swap.h>
28#include <linux/smp.h>
29#include <linux/init.h>
30#include <linux/highmem.h>
31#include <linux/pagemap.h>
32#include <linux/poison.h>
33#include <linux/bootmem.h>
34#include <linux/slab.h>
35#include <linux/proc_fs.h>
36#include <linux/efi.h>
37#include <linux/memory_hotplug.h>
38#include <linux/uaccess.h>
39#include <asm/mmu_context.h>
40#include <asm/processor.h>
41#include <asm/system.h>
42#include <asm/pgtable.h>
43#include <asm/pgalloc.h>
44#include <asm/dma.h>
45#include <asm/fixmap.h>
46#include <asm/tlb.h>
47#include <asm/tlbflush.h>
48#include <asm/sections.h>
49#include <asm/setup.h>
50#include <asm/homecache.h>
51#include <hv/hypervisor.h>
52#include <arch/chip.h>
53
54#include "migrate.h"
55
56#define clear_pgd(pmdptr) (*(pmdptr) = hv_pte(0))
57
58#ifndef __tilegx__
59unsigned long VMALLOC_RESERVE = CONFIG_VMALLOC_RESERVE;
60EXPORT_SYMBOL(VMALLOC_RESERVE);
61#endif
62
63/* Create an L2 page table */
64static pte_t * __init alloc_pte(void)
65{
66 return __alloc_bootmem(L2_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
67}
68
69/*
70 * L2 page tables per controller. We allocate these all at once from
71 * the bootmem allocator and store them here. This saves on kernel L2
72 * page table memory, compared to allocating a full 64K page per L2
73 * page table, and also means that in cases where we use huge pages,
74 * we are guaranteed to later be able to shatter those huge pages and
75 * switch to using these page tables instead, without requiring
76 * further allocation. Each l2_ptes[] entry points to the first page
77 * table for the first hugepage-size piece of memory on the
78 * controller; other page tables are just indexed directly, i.e. the
79 * L2 page tables are contiguous in memory for each controller.
80 */
81static pte_t *l2_ptes[MAX_NUMNODES];
82static int num_l2_ptes[MAX_NUMNODES];
83
84static void init_prealloc_ptes(int node, int pages)
85{
86 BUG_ON(pages & (HV_L2_ENTRIES-1));
87 if (pages) {
88 num_l2_ptes[node] = pages;
89 l2_ptes[node] = __alloc_bootmem(pages * sizeof(pte_t),
90 HV_PAGE_TABLE_ALIGN, 0);
91 }
92}
93
94pte_t *get_prealloc_pte(unsigned long pfn)
95{
96 int node = pfn_to_nid(pfn);
97 pfn &= ~(-1UL << (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT));
98 BUG_ON(node >= MAX_NUMNODES);
99 BUG_ON(pfn >= num_l2_ptes[node]);
100 return &l2_ptes[node][pfn];
101}
102
103/*
104 * What caching do we expect pages from the heap to have when
105 * they are allocated during bootup? (Once we've installed the
106 * "real" swapper_pg_dir.)
107 */
108static int initial_heap_home(void)
109{
110#if CHIP_HAS_CBOX_HOME_MAP()
111 if (hash_default)
112 return PAGE_HOME_HASH;
113#endif
114 return smp_processor_id();
115}
116
117/*
118 * Place a pointer to an L2 page table in a middle page
119 * directory entry.
120 */
121static void __init assign_pte(pmd_t *pmd, pte_t *page_table)
122{
123 phys_addr_t pa = __pa(page_table);
124 unsigned long l2_ptfn = pa >> HV_LOG2_PAGE_TABLE_ALIGN;
125 pte_t pteval = hv_pte_set_ptfn(__pgprot(_PAGE_TABLE), l2_ptfn);
126 BUG_ON((pa & (HV_PAGE_TABLE_ALIGN-1)) != 0);
127 pteval = pte_set_home(pteval, initial_heap_home());
128 *(pte_t *)pmd = pteval;
129 if (page_table != (pte_t *)pmd_page_vaddr(*pmd))
130 BUG();
131}
132
133#ifdef __tilegx__
134
135#if HV_L1_SIZE != HV_L2_SIZE
136# error Rework assumption that L1 and L2 page tables are same size.
137#endif
138
139/* Since pmd_t arrays and pte_t arrays are the same size, just use casts. */
140static inline pmd_t *alloc_pmd(void)
141{
142 return (pmd_t *)alloc_pte();
143}
144
145static inline void assign_pmd(pud_t *pud, pmd_t *pmd)
146{
147 assign_pte((pmd_t *)pud, (pte_t *)pmd);
148}
149
150#endif /* __tilegx__ */
151
152/* Replace the given pmd with a full PTE table. */
153void __init shatter_pmd(pmd_t *pmd)
154{
155 pte_t *pte = get_prealloc_pte(pte_pfn(*(pte_t *)pmd));
156 assign_pte(pmd, pte);
157}
158
159#ifdef CONFIG_HIGHMEM
160/*
161 * This function initializes a certain range of kernel virtual memory
162 * with new bootmem page tables, everywhere page tables are missing in
163 * the given range.
164 */
165
166/*
167 * NOTE: The pagetables are allocated contiguous on the physical space
168 * so we can cache the place of the first one and move around without
169 * checking the pgd every time.
170 */
171static void __init page_table_range_init(unsigned long start,
172 unsigned long end, pgd_t *pgd_base)
173{
174 pgd_t *pgd;
175 int pgd_idx;
176 unsigned long vaddr;
177
178 vaddr = start;
179 pgd_idx = pgd_index(vaddr);
180 pgd = pgd_base + pgd_idx;
181
182 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
183 pmd_t *pmd = pmd_offset(pud_offset(pgd, vaddr), vaddr);
184 if (pmd_none(*pmd))
185 assign_pte(pmd, alloc_pte());
186 vaddr += PMD_SIZE;
187 }
188}
189#endif /* CONFIG_HIGHMEM */
190
191
192#if CHIP_HAS_CBOX_HOME_MAP()
193
194static int __initdata ktext_hash = 1; /* .text pages */
195static int __initdata kdata_hash = 1; /* .data and .bss pages */
196int __write_once hash_default = 1; /* kernel allocator pages */
197EXPORT_SYMBOL(hash_default);
198int __write_once kstack_hash = 1; /* if no homecaching, use h4h */
199#endif /* CHIP_HAS_CBOX_HOME_MAP */
200
201/*
202 * CPUs to use to for striping the pages of kernel data. If hash-for-home
203 * is available, this is only relevant if kcache_hash sets up the
204 * .data and .bss to be page-homed, and we don't want the default mode
205 * of using the full set of kernel cpus for the striping.
206 */
207static __initdata struct cpumask kdata_mask;
208static __initdata int kdata_arg_seen;
209
210int __write_once kdata_huge; /* if no homecaching, small pages */
211
212
213/* Combine a generic pgprot_t with cache home to get a cache-aware pgprot. */
214static pgprot_t __init construct_pgprot(pgprot_t prot, int home)
215{
216 prot = pte_set_home(prot, home);
217#if CHIP_HAS_CBOX_HOME_MAP()
218 if (home == PAGE_HOME_IMMUTABLE) {
219 if (ktext_hash)
220 prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_HASH_L3);
221 else
222 prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_NO_L3);
223 }
224#endif
225 return prot;
226}
227
228/*
229 * For a given kernel data VA, how should it be cached?
230 * We return the complete pgprot_t with caching bits set.
231 */
232static pgprot_t __init init_pgprot(ulong address)
233{
234 int cpu;
235 unsigned long page;
236 enum { CODE_DELTA = MEM_SV_INTRPT - PAGE_OFFSET };
237
238#if CHIP_HAS_CBOX_HOME_MAP()
239 /* For kdata=huge, everything is just hash-for-home. */
240 if (kdata_huge)
241 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
242#endif
243
244 /* We map the aliased pages of permanent text inaccessible. */
245 if (address < (ulong) _sinittext - CODE_DELTA)
246 return PAGE_NONE;
247
248 /*
249 * We map read-only data non-coherent for performance. We could
250 * use neighborhood caching on TILE64, but it's not clear it's a win.
251 */
252 if ((address >= (ulong) __start_rodata &&
253 address < (ulong) __end_rodata) ||
254 address == (ulong) empty_zero_page) {
255 return construct_pgprot(PAGE_KERNEL_RO, PAGE_HOME_IMMUTABLE);
256 }
257
258 /* As a performance optimization, keep the boot init stack here. */
259 if (address >= (ulong)&init_thread_union &&
260 address < (ulong)&init_thread_union + THREAD_SIZE)
261 return construct_pgprot(PAGE_KERNEL, smp_processor_id());
262
263#ifndef __tilegx__
264#if !ATOMIC_LOCKS_FOUND_VIA_TABLE()
265 /* Force the atomic_locks[] array page to be hash-for-home. */
266 if (address == (ulong) atomic_locks)
267 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
268#endif
269#endif
270
271 /*
272 * Everything else that isn't data or bss is heap, so mark it
273 * with the initial heap home (hash-for-home, or this cpu). This
274 * includes any addresses after the loaded image and any address before
275 * _einitdata, since we already captured the case of text before
276 * _sinittext, and __pa(einittext) is approximately __pa(sinitdata).
277 *
278 * All the LOWMEM pages that we mark this way will get their
279 * struct page homecache properly marked later, in set_page_homes().
280 * The HIGHMEM pages we leave with a default zero for their
281 * homes, but with a zero free_time we don't have to actually
282 * do a flush action the first time we use them, either.
283 */
284 if (address >= (ulong) _end || address < (ulong) _einitdata)
285 return construct_pgprot(PAGE_KERNEL, initial_heap_home());
286
287#if CHIP_HAS_CBOX_HOME_MAP()
288 /* Use hash-for-home if requested for data/bss. */
289 if (kdata_hash)
290 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
291#endif
292
293 /*
294 * Make the w1data homed like heap to start with, to avoid
295 * making it part of the page-striped data area when we're just
296 * going to convert it to read-only soon anyway.
297 */
298 if (address >= (ulong)__w1data_begin && address < (ulong)__w1data_end)
299 return construct_pgprot(PAGE_KERNEL, initial_heap_home());
300
301 /*
302 * Otherwise we just hand out consecutive cpus. To avoid
303 * requiring this function to hold state, we just walk forward from
304 * _sdata by PAGE_SIZE, skipping the readonly and init data, to reach
305 * the requested address, while walking cpu home around kdata_mask.
306 * This is typically no more than a dozen or so iterations.
307 */
308 page = (((ulong)__w1data_end) + PAGE_SIZE - 1) & PAGE_MASK;
309 BUG_ON(address < page || address >= (ulong)_end);
310 cpu = cpumask_first(&kdata_mask);
311 for (; page < address; page += PAGE_SIZE) {
312 if (page >= (ulong)&init_thread_union &&
313 page < (ulong)&init_thread_union + THREAD_SIZE)
314 continue;
315 if (page == (ulong)empty_zero_page)
316 continue;
317#ifndef __tilegx__
318#if !ATOMIC_LOCKS_FOUND_VIA_TABLE()
319 if (page == (ulong)atomic_locks)
320 continue;
321#endif
322#endif
323 cpu = cpumask_next(cpu, &kdata_mask);
324 if (cpu == NR_CPUS)
325 cpu = cpumask_first(&kdata_mask);
326 }
327 return construct_pgprot(PAGE_KERNEL, cpu);
328}
329
330/*
331 * This function sets up how we cache the kernel text. If we have
332 * hash-for-home support, normally that is used instead (see the
333 * kcache_hash boot flag for more information). But if we end up
334 * using a page-based caching technique, this option sets up the
335 * details of that. In addition, the "ktext=nocache" option may
336 * always be used to disable local caching of text pages, if desired.
337 */
338
339static int __initdata ktext_arg_seen;
340static int __initdata ktext_small;
341static int __initdata ktext_local;
342static int __initdata ktext_all;
343static int __initdata ktext_nondataplane;
344static int __initdata ktext_nocache;
345static struct cpumask __initdata ktext_mask;
346
347static int __init setup_ktext(char *str)
348{
349 if (str == NULL)
350 return -EINVAL;
351
352 /* If you have a leading "nocache", turn off ktext caching */
353 if (strncmp(str, "nocache", 7) == 0) {
354 ktext_nocache = 1;
355 pr_info("ktext: disabling local caching of kernel text\n");
356 str += 7;
357 if (*str == ',')
358 ++str;
359 if (*str == '\0')
360 return 0;
361 }
362
363 ktext_arg_seen = 1;
364
365 /* Default setting on Tile64: use a huge page */
366 if (strcmp(str, "huge") == 0)
367 pr_info("ktext: using one huge locally cached page\n");
368
369 /* Pay TLB cost but get no cache benefit: cache small pages locally */
370 else if (strcmp(str, "local") == 0) {
371 ktext_small = 1;
372 ktext_local = 1;
373 pr_info("ktext: using small pages with local caching\n");
374 }
375
376 /* Neighborhood cache ktext pages on all cpus. */
377 else if (strcmp(str, "all") == 0) {
378 ktext_small = 1;
379 ktext_all = 1;
380 pr_info("ktext: using maximal caching neighborhood\n");
381 }
382
383
384 /* Neighborhood ktext pages on specified mask */
385 else if (cpulist_parse(str, &ktext_mask) == 0) {
386 char buf[NR_CPUS * 5];
387 cpulist_scnprintf(buf, sizeof(buf), &ktext_mask);
388 if (cpumask_weight(&ktext_mask) > 1) {
389 ktext_small = 1;
390 pr_info("ktext: using caching neighborhood %s "
391 "with small pages\n", buf);
392 } else {
393 pr_info("ktext: caching on cpu %s with one huge page\n",
394 buf);
395 }
396 }
397
398 else if (*str)
399 return -EINVAL;
400
401 return 0;
402}
403
404early_param("ktext", setup_ktext);
405
406
407static inline pgprot_t ktext_set_nocache(pgprot_t prot)
408{
409 if (!ktext_nocache)
410 prot = hv_pte_set_nc(prot);
411#if CHIP_HAS_NC_AND_NOALLOC_BITS()
412 else
413 prot = hv_pte_set_no_alloc_l2(prot);
414#endif
415 return prot;
416}
417
418#ifndef __tilegx__
419static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
420{
421 return pmd_offset(pud_offset(&pgtables[pgd_index(va)], va), va);
422}
423#else
424static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
425{
426 pud_t *pud = pud_offset(&pgtables[pgd_index(va)], va);
427 if (pud_none(*pud))
428 assign_pmd(pud, alloc_pmd());
429 return pmd_offset(pud, va);
430}
431#endif
432
433/* Temporary page table we use for staging. */
434static pgd_t pgtables[PTRS_PER_PGD]
435 __attribute__((aligned(HV_PAGE_TABLE_ALIGN)));
436
437/*
438 * This maps the physical memory to kernel virtual address space, a total
439 * of max_low_pfn pages, by creating page tables starting from address
440 * PAGE_OFFSET.
441 *
442 * This routine transitions us from using a set of compiled-in large
443 * pages to using some more precise caching, including removing access
444 * to code pages mapped at PAGE_OFFSET (executed only at MEM_SV_START)
445 * marking read-only data as locally cacheable, striping the remaining
446 * .data and .bss across all the available tiles, and removing access
447 * to pages above the top of RAM (thus ensuring a page fault from a bad
448 * virtual address rather than a hypervisor shoot down for accessing
449 * memory outside the assigned limits).
450 */
451static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
452{
453 unsigned long address, pfn;
454 pmd_t *pmd;
455 pte_t *pte;
456 int pte_ofs;
457 const struct cpumask *my_cpu_mask = cpumask_of(smp_processor_id());
458 struct cpumask kstripe_mask;
459 int rc, i;
460
461#if CHIP_HAS_CBOX_HOME_MAP()
462 if (ktext_arg_seen && ktext_hash) {
463 pr_warning("warning: \"ktext\" boot argument ignored"
464 " if \"kcache_hash\" sets up text hash-for-home\n");
465 ktext_small = 0;
466 }
467
468 if (kdata_arg_seen && kdata_hash) {
469 pr_warning("warning: \"kdata\" boot argument ignored"
470 " if \"kcache_hash\" sets up data hash-for-home\n");
471 }
472
473 if (kdata_huge && !hash_default) {
474 pr_warning("warning: disabling \"kdata=huge\"; requires"
475 " kcache_hash=all or =allbutstack\n");
476 kdata_huge = 0;
477 }
478#endif
479
480 /*
481 * Set up a mask for cpus to use for kernel striping.
482 * This is normally all cpus, but minus dataplane cpus if any.
483 * If the dataplane covers the whole chip, we stripe over
484 * the whole chip too.
485 */
486 cpumask_copy(&kstripe_mask, cpu_possible_mask);
487 if (!kdata_arg_seen)
488 kdata_mask = kstripe_mask;
489
490 /* Allocate and fill in L2 page tables */
491 for (i = 0; i < MAX_NUMNODES; ++i) {
492#ifdef CONFIG_HIGHMEM
493 unsigned long end_pfn = node_lowmem_end_pfn[i];
494#else
495 unsigned long end_pfn = node_end_pfn[i];
496#endif
497 unsigned long end_huge_pfn = 0;
498
499 /* Pre-shatter the last huge page to allow per-cpu pages. */
500 if (kdata_huge)
501 end_huge_pfn = end_pfn - (HPAGE_SIZE >> PAGE_SHIFT);
502
503 pfn = node_start_pfn[i];
504
505 /* Allocate enough memory to hold L2 page tables for node. */
506 init_prealloc_ptes(i, end_pfn - pfn);
507
508 address = (unsigned long) pfn_to_kaddr(pfn);
509 while (pfn < end_pfn) {
510 BUG_ON(address & (HPAGE_SIZE-1));
511 pmd = get_pmd(pgtables, address);
512 pte = get_prealloc_pte(pfn);
513 if (pfn < end_huge_pfn) {
514 pgprot_t prot = init_pgprot(address);
515 *(pte_t *)pmd = pte_mkhuge(pfn_pte(pfn, prot));
516 for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
517 pfn++, pte_ofs++, address += PAGE_SIZE)
518 pte[pte_ofs] = pfn_pte(pfn, prot);
519 } else {
520 if (kdata_huge)
521 printk(KERN_DEBUG "pre-shattered huge"
522 " page at %#lx\n", address);
523 for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
524 pfn++, pte_ofs++, address += PAGE_SIZE) {
525 pgprot_t prot = init_pgprot(address);
526 pte[pte_ofs] = pfn_pte(pfn, prot);
527 }
528 assign_pte(pmd, pte);
529 }
530 }
531 }
532
533 /*
534 * Set or check ktext_map now that we have cpu_possible_mask
535 * and kstripe_mask to work with.
536 */
537 if (ktext_all)
538 cpumask_copy(&ktext_mask, cpu_possible_mask);
539 else if (ktext_nondataplane)
540 ktext_mask = kstripe_mask;
541 else if (!cpumask_empty(&ktext_mask)) {
542 /* Sanity-check any mask that was requested */
543 struct cpumask bad;
544 cpumask_andnot(&bad, &ktext_mask, cpu_possible_mask);
545 cpumask_and(&ktext_mask, &ktext_mask, cpu_possible_mask);
546 if (!cpumask_empty(&bad)) {
547 char buf[NR_CPUS * 5];
548 cpulist_scnprintf(buf, sizeof(buf), &bad);
549 pr_info("ktext: not using unavailable cpus %s\n", buf);
550 }
551 if (cpumask_empty(&ktext_mask)) {
552 pr_warning("ktext: no valid cpus; caching on %d.\n",
553 smp_processor_id());
554 cpumask_copy(&ktext_mask,
555 cpumask_of(smp_processor_id()));
556 }
557 }
558
559 address = MEM_SV_INTRPT;
560 pmd = get_pmd(pgtables, address);
561 if (ktext_small) {
562 /* Allocate an L2 PTE for the kernel text */
563 int cpu = 0;
564 pgprot_t prot = construct_pgprot(PAGE_KERNEL_EXEC,
565 PAGE_HOME_IMMUTABLE);
566
567 if (ktext_local) {
568 if (ktext_nocache)
569 prot = hv_pte_set_mode(prot,
570 HV_PTE_MODE_UNCACHED);
571 else
572 prot = hv_pte_set_mode(prot,
573 HV_PTE_MODE_CACHE_NO_L3);
574 } else {
575 prot = hv_pte_set_mode(prot,
576 HV_PTE_MODE_CACHE_TILE_L3);
577 cpu = cpumask_first(&ktext_mask);
578
579 prot = ktext_set_nocache(prot);
580 }
581
582 BUG_ON(address != (unsigned long)_stext);
583 pfn = 0; /* code starts at PA 0 */
584 pte = alloc_pte();
585 for (pte_ofs = 0; address < (unsigned long)_einittext;
586 pfn++, pte_ofs++, address += PAGE_SIZE) {
587 if (!ktext_local) {
588 prot = set_remote_cache_cpu(prot, cpu);
589 cpu = cpumask_next(cpu, &ktext_mask);
590 if (cpu == NR_CPUS)
591 cpu = cpumask_first(&ktext_mask);
592 }
593 pte[pte_ofs] = pfn_pte(pfn, prot);
594 }
595 assign_pte(pmd, pte);
596 } else {
597 pte_t pteval = pfn_pte(0, PAGE_KERNEL_EXEC);
598 pteval = pte_mkhuge(pteval);
599#if CHIP_HAS_CBOX_HOME_MAP()
600 if (ktext_hash) {
601 pteval = hv_pte_set_mode(pteval,
602 HV_PTE_MODE_CACHE_HASH_L3);
603 pteval = ktext_set_nocache(pteval);
604 } else
605#endif /* CHIP_HAS_CBOX_HOME_MAP() */
606 if (cpumask_weight(&ktext_mask) == 1) {
607 pteval = set_remote_cache_cpu(pteval,
608 cpumask_first(&ktext_mask));
609 pteval = hv_pte_set_mode(pteval,
610 HV_PTE_MODE_CACHE_TILE_L3);
611 pteval = ktext_set_nocache(pteval);
612 } else if (ktext_nocache)
613 pteval = hv_pte_set_mode(pteval,
614 HV_PTE_MODE_UNCACHED);
615 else
616 pteval = hv_pte_set_mode(pteval,
617 HV_PTE_MODE_CACHE_NO_L3);
618 *(pte_t *)pmd = pteval;
619 }
620
621 /* Set swapper_pgprot here so it is flushed to memory right away. */
622 swapper_pgprot = init_pgprot((unsigned long)swapper_pg_dir);
623
624 /*
625 * Since we may be changing the caching of the stack and page
626 * table itself, we invoke an assembly helper to do the
627 * following steps:
628 *
629 * - flush the cache so we start with an empty slate
630 * - install pgtables[] as the real page table
631 * - flush the TLB so the new page table takes effect
632 */
633 rc = flush_and_install_context(__pa(pgtables),
634 init_pgprot((unsigned long)pgtables),
635 __get_cpu_var(current_asid),
636 cpumask_bits(my_cpu_mask));
637 BUG_ON(rc != 0);
638
639 /* Copy the page table back to the normal swapper_pg_dir. */
640 memcpy(pgd_base, pgtables, sizeof(pgtables));
641 __install_page_table(pgd_base, __get_cpu_var(current_asid),
642 swapper_pgprot);
643
644 /*
645 * We just read swapper_pgprot and thus brought it into the cache,
646 * with its new home & caching mode. When we start the other CPUs,
647 * they're going to reference swapper_pgprot via their initial fake
648 * VA-is-PA mappings, which cache everything locally. At that
649 * time, if it's in our cache with a conflicting home, the
650 * simulator's coherence checker will complain. So, flush it out
651 * of our cache; we're not going to ever use it again anyway.
652 */
653 __insn_finv(&swapper_pgprot);
654}
655
656/*
657 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
658 * is valid. The argument is a physical page number.
659 *
660 * On Tile, the only valid things for which we can just hand out unchecked
661 * PTEs are the kernel code and data. Anything else might change its
662 * homing with time, and we wouldn't know to adjust the /dev/mem PTEs.
663 * Note that init_thread_union is released to heap soon after boot,
664 * so we include it in the init data.
665 *
666 * For TILE-Gx, we might want to consider allowing access to PA
667 * regions corresponding to PCI space, etc.
668 */
669int devmem_is_allowed(unsigned long pagenr)
670{
671 return pagenr < kaddr_to_pfn(_end) &&
672 !(pagenr >= kaddr_to_pfn(&init_thread_union) ||
673 pagenr < kaddr_to_pfn(_einitdata)) &&
674 !(pagenr >= kaddr_to_pfn(_sinittext) ||
675 pagenr <= kaddr_to_pfn(_einittext-1));
676}
677
678#ifdef CONFIG_HIGHMEM
679static void __init permanent_kmaps_init(pgd_t *pgd_base)
680{
681 pgd_t *pgd;
682 pud_t *pud;
683 pmd_t *pmd;
684 pte_t *pte;
685 unsigned long vaddr;
686
687 vaddr = PKMAP_BASE;
688 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
689
690 pgd = swapper_pg_dir + pgd_index(vaddr);
691 pud = pud_offset(pgd, vaddr);
692 pmd = pmd_offset(pud, vaddr);
693 pte = pte_offset_kernel(pmd, vaddr);
694 pkmap_page_table = pte;
695}
696#endif /* CONFIG_HIGHMEM */
697
698
699static void __init init_free_pfn_range(unsigned long start, unsigned long end)
700{
701 unsigned long pfn;
702 struct page *page = pfn_to_page(start);
703
704 for (pfn = start; pfn < end; ) {
705 /* Optimize by freeing pages in large batches */
706 int order = __ffs(pfn);
707 int count, i;
708 struct page *p;
709
710 if (order >= MAX_ORDER)
711 order = MAX_ORDER-1;
712 count = 1 << order;
713 while (pfn + count > end) {
714 count >>= 1;
715 --order;
716 }
717 for (p = page, i = 0; i < count; ++i, ++p) {
718 __ClearPageReserved(p);
719 /*
720 * Hacky direct set to avoid unnecessary
721 * lock take/release for EVERY page here.
722 */
723 p->_count.counter = 0;
724 p->_mapcount.counter = -1;
725 }
726 init_page_count(page);
727 __free_pages(page, order);
728 totalram_pages += count;
729
730 page += count;
731 pfn += count;
732 }
733}
734
735static void __init set_non_bootmem_pages_init(void)
736{
737 struct zone *z;
738 for_each_zone(z) {
739 unsigned long start, end;
740 int nid = z->zone_pgdat->node_id;
741 int idx = zone_idx(z);
742
743 start = z->zone_start_pfn;
744 if (start == 0)
745 continue; /* bootmem */
746 end = start + z->spanned_pages;
747 if (idx == ZONE_NORMAL) {
748 BUG_ON(start != node_start_pfn[nid]);
749 start = node_free_pfn[nid];
750 }
751#ifdef CONFIG_HIGHMEM
752 if (idx == ZONE_HIGHMEM)
753 totalhigh_pages += z->spanned_pages;
754#endif
755 if (kdata_huge) {
756 unsigned long percpu_pfn = node_percpu_pfn[nid];
757 if (start < percpu_pfn && end > percpu_pfn)
758 end = percpu_pfn;
759 }
760#ifdef CONFIG_PCI
761 if (start <= pci_reserve_start_pfn &&
762 end > pci_reserve_start_pfn) {
763 if (end > pci_reserve_end_pfn)
764 init_free_pfn_range(pci_reserve_end_pfn, end);
765 end = pci_reserve_start_pfn;
766 }
767#endif
768 init_free_pfn_range(start, end);
769 }
770}
771
772/*
773 * paging_init() sets up the page tables - note that all of lowmem is
774 * already mapped by head.S.
775 */
776void __init paging_init(void)
777{
778#ifdef CONFIG_HIGHMEM
779 unsigned long vaddr, end;
780#endif
781#ifdef __tilegx__
782 pud_t *pud;
783#endif
784 pgd_t *pgd_base = swapper_pg_dir;
785
786 kernel_physical_mapping_init(pgd_base);
787
788#ifdef CONFIG_HIGHMEM
789 /*
790 * Fixed mappings, only the page table structure has to be
791 * created - mappings will be set by set_fixmap():
792 */
793 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
794 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
795 page_table_range_init(vaddr, end, pgd_base);
796 permanent_kmaps_init(pgd_base);
797#endif
798
799#ifdef __tilegx__
800 /*
801 * Since GX allocates just one pmd_t array worth of vmalloc space,
802 * we go ahead and allocate it statically here, then share it
803 * globally. As a result we don't have to worry about any task
804 * changing init_mm once we get up and running, and there's no
805 * need for e.g. vmalloc_sync_all().
806 */
807 BUILD_BUG_ON(pgd_index(VMALLOC_START) != pgd_index(VMALLOC_END));
808 pud = pud_offset(pgd_base + pgd_index(VMALLOC_START), VMALLOC_START);
809 assign_pmd(pud, alloc_pmd());
810#endif
811}
812
813
814/*
815 * Walk the kernel page tables and derive the page_home() from
816 * the PTEs, so that set_pte() can properly validate the caching
817 * of all PTEs it sees.
818 */
819void __init set_page_homes(void)
820{
821}
822
823static void __init set_max_mapnr_init(void)
824{
825#ifdef CONFIG_FLATMEM
826 max_mapnr = max_low_pfn;
827#endif
828}
829
830void __init mem_init(void)
831{
832 int codesize, datasize, initsize;
833 int i;
834#ifndef __tilegx__
835 void *last;
836#endif
837
838#ifdef CONFIG_FLATMEM
839 BUG_ON(!mem_map);
840#endif
841
842#ifdef CONFIG_HIGHMEM
843 /* check that fixmap and pkmap do not overlap */
844 if (PKMAP_ADDR(LAST_PKMAP-1) >= FIXADDR_START) {
845 pr_err("fixmap and kmap areas overlap"
846 " - this will crash\n");
847 pr_err("pkstart: %lxh pkend: %lxh fixstart %lxh\n",
848 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP-1),
849 FIXADDR_START);
850 BUG();
851 }
852#endif
853
854 set_max_mapnr_init();
855
856 /* this will put all bootmem onto the freelists */
857 totalram_pages += free_all_bootmem();
858
859 /* count all remaining LOWMEM and give all HIGHMEM to page allocator */
860 set_non_bootmem_pages_init();
861
862 codesize = (unsigned long)&_etext - (unsigned long)&_text;
863 datasize = (unsigned long)&_end - (unsigned long)&_sdata;
864 initsize = (unsigned long)&_einittext - (unsigned long)&_sinittext;
865 initsize += (unsigned long)&_einitdata - (unsigned long)&_sinitdata;
866
867 pr_info("Memory: %luk/%luk available (%dk kernel code, %dk data, %dk init, %ldk highmem)\n",
868 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
869 num_physpages << (PAGE_SHIFT-10),
870 codesize >> 10,
871 datasize >> 10,
872 initsize >> 10,
873 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
874 );
875
876 /*
877 * In debug mode, dump some interesting memory mappings.
878 */
879#ifdef CONFIG_HIGHMEM
880 printk(KERN_DEBUG " KMAP %#lx - %#lx\n",
881 FIXADDR_START, FIXADDR_TOP + PAGE_SIZE - 1);
882 printk(KERN_DEBUG " PKMAP %#lx - %#lx\n",
883 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP) - 1);
884#endif
885#ifdef CONFIG_HUGEVMAP
886 printk(KERN_DEBUG " HUGEMAP %#lx - %#lx\n",
887 HUGE_VMAP_BASE, HUGE_VMAP_END - 1);
888#endif
889 printk(KERN_DEBUG " VMALLOC %#lx - %#lx\n",
890 _VMALLOC_START, _VMALLOC_END - 1);
891#ifdef __tilegx__
892 for (i = MAX_NUMNODES-1; i >= 0; --i) {
893 struct pglist_data *node = &node_data[i];
894 if (node->node_present_pages) {
895 unsigned long start = (unsigned long)
896 pfn_to_kaddr(node->node_start_pfn);
897 unsigned long end = start +
898 (node->node_present_pages << PAGE_SHIFT);
899 printk(KERN_DEBUG " MEM%d %#lx - %#lx\n",
900 i, start, end - 1);
901 }
902 }
903#else
904 last = high_memory;
905 for (i = MAX_NUMNODES-1; i >= 0; --i) {
906 if ((unsigned long)vbase_map[i] != -1UL) {
907 printk(KERN_DEBUG " LOWMEM%d %#lx - %#lx\n",
908 i, (unsigned long) (vbase_map[i]),
909 (unsigned long) (last-1));
910 last = vbase_map[i];
911 }
912 }
913#endif
914
915#ifndef __tilegx__
916 /*
917 * Convert from using one lock for all atomic operations to
918 * one per cpu.
919 */
920 __init_atomic_per_cpu();
921#endif
922}
923
924/*
925 * this is for the non-NUMA, single node SMP system case.
926 * Specifically, in the case of x86, we will always add
927 * memory to the highmem for now.
928 */
929#ifndef CONFIG_NEED_MULTIPLE_NODES
930int arch_add_memory(u64 start, u64 size)
931{
932 struct pglist_data *pgdata = &contig_page_data;
933 struct zone *zone = pgdata->node_zones + MAX_NR_ZONES-1;
934 unsigned long start_pfn = start >> PAGE_SHIFT;
935 unsigned long nr_pages = size >> PAGE_SHIFT;
936
937 return __add_pages(zone, start_pfn, nr_pages);
938}
939
940int remove_memory(u64 start, u64 size)
941{
942 return -EINVAL;
943}
944#endif
945
946struct kmem_cache *pgd_cache;
947
948void __init pgtable_cache_init(void)
949{
950 pgd_cache = kmem_cache_create("pgd", SIZEOF_PGD, SIZEOF_PGD, 0, NULL);
951 if (!pgd_cache)
952 panic("pgtable_cache_init(): Cannot create pgd cache");
953}
954
955#if !CHIP_HAS_COHERENT_LOCAL_CACHE()
956/*
957 * The __w1data area holds data that is only written during initialization,
958 * and is read-only and thus freely cacheable thereafter. Fix the page
959 * table entries that cover that region accordingly.
960 */
961static void mark_w1data_ro(void)
962{
963 /* Loop over page table entries */
964 unsigned long addr = (unsigned long)__w1data_begin;
965 BUG_ON((addr & (PAGE_SIZE-1)) != 0);
966 for (; addr <= (unsigned long)__w1data_end - 1; addr += PAGE_SIZE) {
967 unsigned long pfn = kaddr_to_pfn((void *)addr);
968 pte_t *ptep = virt_to_pte(NULL, addr);
969 BUG_ON(pte_huge(*ptep)); /* not relevant for kdata_huge */
970 set_pte_at(&init_mm, addr, ptep, pfn_pte(pfn, PAGE_KERNEL_RO));
971 }
972}
973#endif
974
975#ifdef CONFIG_DEBUG_PAGEALLOC
976static long __write_once initfree;
977#else
978static long __write_once initfree = 1;
979#endif
980
981/* Select whether to free (1) or mark unusable (0) the __init pages. */
982static int __init set_initfree(char *str)
983{
984 long val;
985 if (strict_strtol(str, 0, &val) == 0) {
986 initfree = val;
987 pr_info("initfree: %s free init pages\n",
988 initfree ? "will" : "won't");
989 }
990 return 1;
991}
992__setup("initfree=", set_initfree);
993
994static void free_init_pages(char *what, unsigned long begin, unsigned long end)
995{
996 unsigned long addr = (unsigned long) begin;
997
998 if (kdata_huge && !initfree) {
999 pr_warning("Warning: ignoring initfree=0:"
1000 " incompatible with kdata=huge\n");
1001 initfree = 1;
1002 }
1003 end = (end + PAGE_SIZE - 1) & PAGE_MASK;
1004 local_flush_tlb_pages(NULL, begin, PAGE_SIZE, end - begin);
1005 for (addr = begin; addr < end; addr += PAGE_SIZE) {
1006 /*
1007 * Note we just reset the home here directly in the
1008 * page table. We know this is safe because our caller
1009 * just flushed the caches on all the other cpus,
1010 * and they won't be touching any of these pages.
1011 */
1012 int pfn = kaddr_to_pfn((void *)addr);
1013 struct page *page = pfn_to_page(pfn);
1014 pte_t *ptep = virt_to_pte(NULL, addr);
1015 if (!initfree) {
1016 /*
1017 * If debugging page accesses then do not free
1018 * this memory but mark them not present - any
1019 * buggy init-section access will create a
1020 * kernel page fault:
1021 */
1022 pte_clear(&init_mm, addr, ptep);
1023 continue;
1024 }
1025 __ClearPageReserved(page);
1026 init_page_count(page);
1027 if (pte_huge(*ptep))
1028 BUG_ON(!kdata_huge);
1029 else
1030 set_pte_at(&init_mm, addr, ptep,
1031 pfn_pte(pfn, PAGE_KERNEL));
1032 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
1033 free_page(addr);
1034 totalram_pages++;
1035 }
1036 pr_info("Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
1037}
1038
1039void free_initmem(void)
1040{
1041 const unsigned long text_delta = MEM_SV_INTRPT - PAGE_OFFSET;
1042
1043 /*
1044 * Evict the dirty initdata on the boot cpu, evict the w1data
1045 * wherever it's homed, and evict all the init code everywhere.
1046 * We are guaranteed that no one will touch the init pages any
1047 * more, and although other cpus may be touching the w1data,
1048 * we only actually change the caching on tile64, which won't
1049 * be keeping local copies in the other tiles' caches anyway.
1050 */
1051 homecache_evict(&cpu_cacheable_map);
1052
1053 /* Free the data pages that we won't use again after init. */
1054 free_init_pages("unused kernel data",
1055 (unsigned long)_sinitdata,
1056 (unsigned long)_einitdata);
1057
1058 /*
1059 * Free the pages mapped from 0xc0000000 that correspond to code
1060 * pages from MEM_SV_INTRPT that we won't use again after init.
1061 */
1062 free_init_pages("unused kernel text",
1063 (unsigned long)_sinittext - text_delta,
1064 (unsigned long)_einittext - text_delta);
1065
1066#if !CHIP_HAS_COHERENT_LOCAL_CACHE()
1067 /*
1068 * Upgrade the .w1data section to globally cached.
1069 * We don't do this on tilepro, since the cache architecture
1070 * pretty much makes it irrelevant, and in any case we end
1071 * up having racing issues with other tiles that may touch
1072 * the data after we flush the cache but before we update
1073 * the PTEs and flush the TLBs, causing sharer shootdowns
1074 * later. Even though this is to clean data, it seems like
1075 * an unnecessary complication.
1076 */
1077 mark_w1data_ro();
1078#endif
1079
1080 /* Do a global TLB flush so everyone sees the changes. */
1081 flush_tlb_all();
1082}
1/*
2 * Copyright (C) 1995 Linus Torvalds
3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation, version 2.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
12 * NON INFRINGEMENT. See the GNU General Public License for
13 * more details.
14 */
15
16#include <linux/module.h>
17#include <linux/signal.h>
18#include <linux/sched.h>
19#include <linux/kernel.h>
20#include <linux/errno.h>
21#include <linux/string.h>
22#include <linux/types.h>
23#include <linux/ptrace.h>
24#include <linux/mman.h>
25#include <linux/mm.h>
26#include <linux/hugetlb.h>
27#include <linux/swap.h>
28#include <linux/smp.h>
29#include <linux/init.h>
30#include <linux/highmem.h>
31#include <linux/pagemap.h>
32#include <linux/poison.h>
33#include <linux/bootmem.h>
34#include <linux/slab.h>
35#include <linux/proc_fs.h>
36#include <linux/efi.h>
37#include <linux/memory_hotplug.h>
38#include <linux/uaccess.h>
39#include <asm/mmu_context.h>
40#include <asm/processor.h>
41#include <asm/pgtable.h>
42#include <asm/pgalloc.h>
43#include <asm/dma.h>
44#include <asm/fixmap.h>
45#include <asm/tlb.h>
46#include <asm/tlbflush.h>
47#include <asm/sections.h>
48#include <asm/setup.h>
49#include <asm/homecache.h>
50#include <hv/hypervisor.h>
51#include <arch/chip.h>
52
53#include "migrate.h"
54
55#define clear_pgd(pmdptr) (*(pmdptr) = hv_pte(0))
56
57#ifndef __tilegx__
58unsigned long VMALLOC_RESERVE = CONFIG_VMALLOC_RESERVE;
59EXPORT_SYMBOL(VMALLOC_RESERVE);
60#endif
61
62/* Create an L2 page table */
63static pte_t * __init alloc_pte(void)
64{
65 return __alloc_bootmem(L2_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
66}
67
68/*
69 * L2 page tables per controller. We allocate these all at once from
70 * the bootmem allocator and store them here. This saves on kernel L2
71 * page table memory, compared to allocating a full 64K page per L2
72 * page table, and also means that in cases where we use huge pages,
73 * we are guaranteed to later be able to shatter those huge pages and
74 * switch to using these page tables instead, without requiring
75 * further allocation. Each l2_ptes[] entry points to the first page
76 * table for the first hugepage-size piece of memory on the
77 * controller; other page tables are just indexed directly, i.e. the
78 * L2 page tables are contiguous in memory for each controller.
79 */
80static pte_t *l2_ptes[MAX_NUMNODES];
81static int num_l2_ptes[MAX_NUMNODES];
82
83static void init_prealloc_ptes(int node, int pages)
84{
85 BUG_ON(pages & (PTRS_PER_PTE - 1));
86 if (pages) {
87 num_l2_ptes[node] = pages;
88 l2_ptes[node] = __alloc_bootmem(pages * sizeof(pte_t),
89 HV_PAGE_TABLE_ALIGN, 0);
90 }
91}
92
93pte_t *get_prealloc_pte(unsigned long pfn)
94{
95 int node = pfn_to_nid(pfn);
96 pfn &= ~(-1UL << (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT));
97 BUG_ON(node >= MAX_NUMNODES);
98 BUG_ON(pfn >= num_l2_ptes[node]);
99 return &l2_ptes[node][pfn];
100}
101
102/*
103 * What caching do we expect pages from the heap to have when
104 * they are allocated during bootup? (Once we've installed the
105 * "real" swapper_pg_dir.)
106 */
107static int initial_heap_home(void)
108{
109 if (hash_default)
110 return PAGE_HOME_HASH;
111 return smp_processor_id();
112}
113
114/*
115 * Place a pointer to an L2 page table in a middle page
116 * directory entry.
117 */
118static void __init assign_pte(pmd_t *pmd, pte_t *page_table)
119{
120 phys_addr_t pa = __pa(page_table);
121 unsigned long l2_ptfn = pa >> HV_LOG2_PAGE_TABLE_ALIGN;
122 pte_t pteval = hv_pte_set_ptfn(__pgprot(_PAGE_TABLE), l2_ptfn);
123 BUG_ON((pa & (HV_PAGE_TABLE_ALIGN-1)) != 0);
124 pteval = pte_set_home(pteval, initial_heap_home());
125 *(pte_t *)pmd = pteval;
126 if (page_table != (pte_t *)pmd_page_vaddr(*pmd))
127 BUG();
128}
129
130#ifdef __tilegx__
131
132static inline pmd_t *alloc_pmd(void)
133{
134 return __alloc_bootmem(L1_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
135}
136
137static inline void assign_pmd(pud_t *pud, pmd_t *pmd)
138{
139 assign_pte((pmd_t *)pud, (pte_t *)pmd);
140}
141
142#endif /* __tilegx__ */
143
144/* Replace the given pmd with a full PTE table. */
145void __init shatter_pmd(pmd_t *pmd)
146{
147 pte_t *pte = get_prealloc_pte(pte_pfn(*(pte_t *)pmd));
148 assign_pte(pmd, pte);
149}
150
151#ifdef __tilegx__
152static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
153{
154 pud_t *pud = pud_offset(&pgtables[pgd_index(va)], va);
155 if (pud_none(*pud))
156 assign_pmd(pud, alloc_pmd());
157 return pmd_offset(pud, va);
158}
159#else
160static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
161{
162 return pmd_offset(pud_offset(&pgtables[pgd_index(va)], va), va);
163}
164#endif
165
166/*
167 * This function initializes a certain range of kernel virtual memory
168 * with new bootmem page tables, everywhere page tables are missing in
169 * the given range.
170 */
171
172/*
173 * NOTE: The pagetables are allocated contiguous on the physical space
174 * so we can cache the place of the first one and move around without
175 * checking the pgd every time.
176 */
177static void __init page_table_range_init(unsigned long start,
178 unsigned long end, pgd_t *pgd)
179{
180 unsigned long vaddr;
181 start = round_down(start, PMD_SIZE);
182 end = round_up(end, PMD_SIZE);
183 for (vaddr = start; vaddr < end; vaddr += PMD_SIZE) {
184 pmd_t *pmd = get_pmd(pgd, vaddr);
185 if (pmd_none(*pmd))
186 assign_pte(pmd, alloc_pte());
187 }
188}
189
190
191static int __initdata ktext_hash = 1; /* .text pages */
192static int __initdata kdata_hash = 1; /* .data and .bss pages */
193int __ro_after_init hash_default = 1; /* kernel allocator pages */
194EXPORT_SYMBOL(hash_default);
195int __ro_after_init kstack_hash = 1; /* if no homecaching, use h4h */
196
197/*
198 * CPUs to use to for striping the pages of kernel data. If hash-for-home
199 * is available, this is only relevant if kcache_hash sets up the
200 * .data and .bss to be page-homed, and we don't want the default mode
201 * of using the full set of kernel cpus for the striping.
202 */
203static __initdata struct cpumask kdata_mask;
204static __initdata int kdata_arg_seen;
205
206int __ro_after_init kdata_huge; /* if no homecaching, small pages */
207
208
209/* Combine a generic pgprot_t with cache home to get a cache-aware pgprot. */
210static pgprot_t __init construct_pgprot(pgprot_t prot, int home)
211{
212 prot = pte_set_home(prot, home);
213 if (home == PAGE_HOME_IMMUTABLE) {
214 if (ktext_hash)
215 prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_HASH_L3);
216 else
217 prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_NO_L3);
218 }
219 return prot;
220}
221
222/*
223 * For a given kernel data VA, how should it be cached?
224 * We return the complete pgprot_t with caching bits set.
225 */
226static pgprot_t __init init_pgprot(ulong address)
227{
228 int cpu;
229 unsigned long page;
230 enum { CODE_DELTA = MEM_SV_START - PAGE_OFFSET };
231
232 /* For kdata=huge, everything is just hash-for-home. */
233 if (kdata_huge)
234 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
235
236 /*
237 * We map the aliased pages of permanent text so we can
238 * update them if necessary, for ftrace, etc.
239 */
240 if (address < (ulong) _sinittext - CODE_DELTA)
241 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
242
243 /* We map read-only data non-coherent for performance. */
244 if ((address >= (ulong) __start_rodata &&
245 address < (ulong) __end_rodata) ||
246 address == (ulong) empty_zero_page) {
247 return construct_pgprot(PAGE_KERNEL_RO, PAGE_HOME_IMMUTABLE);
248 }
249
250#ifndef __tilegx__
251 /* Force the atomic_locks[] array page to be hash-for-home. */
252 if (address == (ulong) atomic_locks)
253 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
254#endif
255
256 /*
257 * Everything else that isn't data or bss is heap, so mark it
258 * with the initial heap home (hash-for-home, or this cpu). This
259 * includes any addresses after the loaded image and any address before
260 * __init_end, since we already captured the case of text before
261 * _sinittext, and __pa(einittext) is approximately __pa(__init_begin).
262 *
263 * All the LOWMEM pages that we mark this way will get their
264 * struct page homecache properly marked later, in set_page_homes().
265 * The HIGHMEM pages we leave with a default zero for their
266 * homes, but with a zero free_time we don't have to actually
267 * do a flush action the first time we use them, either.
268 */
269 if (address >= (ulong) _end || address < (ulong) __init_end)
270 return construct_pgprot(PAGE_KERNEL, initial_heap_home());
271
272 /* Use hash-for-home if requested for data/bss. */
273 if (kdata_hash)
274 return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
275
276 /*
277 * Otherwise we just hand out consecutive cpus. To avoid
278 * requiring this function to hold state, we just walk forward from
279 * __end_rodata by PAGE_SIZE, skipping the readonly and init data, to
280 * reach the requested address, while walking cpu home around
281 * kdata_mask. This is typically no more than a dozen or so iterations.
282 */
283 page = (((ulong)__end_rodata) + PAGE_SIZE - 1) & PAGE_MASK;
284 BUG_ON(address < page || address >= (ulong)_end);
285 cpu = cpumask_first(&kdata_mask);
286 for (; page < address; page += PAGE_SIZE) {
287 if (page >= (ulong)&init_thread_union &&
288 page < (ulong)&init_thread_union + THREAD_SIZE)
289 continue;
290 if (page == (ulong)empty_zero_page)
291 continue;
292#ifndef __tilegx__
293 if (page == (ulong)atomic_locks)
294 continue;
295#endif
296 cpu = cpumask_next(cpu, &kdata_mask);
297 if (cpu == NR_CPUS)
298 cpu = cpumask_first(&kdata_mask);
299 }
300 return construct_pgprot(PAGE_KERNEL, cpu);
301}
302
303/*
304 * This function sets up how we cache the kernel text. If we have
305 * hash-for-home support, normally that is used instead (see the
306 * kcache_hash boot flag for more information). But if we end up
307 * using a page-based caching technique, this option sets up the
308 * details of that. In addition, the "ktext=nocache" option may
309 * always be used to disable local caching of text pages, if desired.
310 */
311
312static int __initdata ktext_arg_seen;
313static int __initdata ktext_small;
314static int __initdata ktext_local;
315static int __initdata ktext_all;
316static int __initdata ktext_nondataplane;
317static int __initdata ktext_nocache;
318static struct cpumask __initdata ktext_mask;
319
320static int __init setup_ktext(char *str)
321{
322 if (str == NULL)
323 return -EINVAL;
324
325 /* If you have a leading "nocache", turn off ktext caching */
326 if (strncmp(str, "nocache", 7) == 0) {
327 ktext_nocache = 1;
328 pr_info("ktext: disabling local caching of kernel text\n");
329 str += 7;
330 if (*str == ',')
331 ++str;
332 if (*str == '\0')
333 return 0;
334 }
335
336 ktext_arg_seen = 1;
337
338 /* Default setting: use a huge page */
339 if (strcmp(str, "huge") == 0)
340 pr_info("ktext: using one huge locally cached page\n");
341
342 /* Pay TLB cost but get no cache benefit: cache small pages locally */
343 else if (strcmp(str, "local") == 0) {
344 ktext_small = 1;
345 ktext_local = 1;
346 pr_info("ktext: using small pages with local caching\n");
347 }
348
349 /* Neighborhood cache ktext pages on all cpus. */
350 else if (strcmp(str, "all") == 0) {
351 ktext_small = 1;
352 ktext_all = 1;
353 pr_info("ktext: using maximal caching neighborhood\n");
354 }
355
356
357 /* Neighborhood ktext pages on specified mask */
358 else if (cpulist_parse(str, &ktext_mask) == 0) {
359 if (cpumask_weight(&ktext_mask) > 1) {
360 ktext_small = 1;
361 pr_info("ktext: using caching neighborhood %*pbl with small pages\n",
362 cpumask_pr_args(&ktext_mask));
363 } else {
364 pr_info("ktext: caching on cpu %*pbl with one huge page\n",
365 cpumask_pr_args(&ktext_mask));
366 }
367 }
368
369 else if (*str)
370 return -EINVAL;
371
372 return 0;
373}
374
375early_param("ktext", setup_ktext);
376
377
378static inline pgprot_t ktext_set_nocache(pgprot_t prot)
379{
380 if (!ktext_nocache)
381 prot = hv_pte_set_nc(prot);
382 else
383 prot = hv_pte_set_no_alloc_l2(prot);
384 return prot;
385}
386
387/* Temporary page table we use for staging. */
388static pgd_t pgtables[PTRS_PER_PGD]
389 __attribute__((aligned(HV_PAGE_TABLE_ALIGN)));
390
391/*
392 * This maps the physical memory to kernel virtual address space, a total
393 * of max_low_pfn pages, by creating page tables starting from address
394 * PAGE_OFFSET.
395 *
396 * This routine transitions us from using a set of compiled-in large
397 * pages to using some more precise caching, including removing access
398 * to code pages mapped at PAGE_OFFSET (executed only at MEM_SV_START)
399 * marking read-only data as locally cacheable, striping the remaining
400 * .data and .bss across all the available tiles, and removing access
401 * to pages above the top of RAM (thus ensuring a page fault from a bad
402 * virtual address rather than a hypervisor shoot down for accessing
403 * memory outside the assigned limits).
404 */
405static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
406{
407 unsigned long long irqmask;
408 unsigned long address, pfn;
409 pmd_t *pmd;
410 pte_t *pte;
411 int pte_ofs;
412 const struct cpumask *my_cpu_mask = cpumask_of(smp_processor_id());
413 struct cpumask kstripe_mask;
414 int rc, i;
415
416 if (ktext_arg_seen && ktext_hash) {
417 pr_warn("warning: \"ktext\" boot argument ignored if \"kcache_hash\" sets up text hash-for-home\n");
418 ktext_small = 0;
419 }
420
421 if (kdata_arg_seen && kdata_hash) {
422 pr_warn("warning: \"kdata\" boot argument ignored if \"kcache_hash\" sets up data hash-for-home\n");
423 }
424
425 if (kdata_huge && !hash_default) {
426 pr_warn("warning: disabling \"kdata=huge\"; requires kcache_hash=all or =allbutstack\n");
427 kdata_huge = 0;
428 }
429
430 /*
431 * Set up a mask for cpus to use for kernel striping.
432 * This is normally all cpus, but minus dataplane cpus if any.
433 * If the dataplane covers the whole chip, we stripe over
434 * the whole chip too.
435 */
436 cpumask_copy(&kstripe_mask, cpu_possible_mask);
437 if (!kdata_arg_seen)
438 kdata_mask = kstripe_mask;
439
440 /* Allocate and fill in L2 page tables */
441 for (i = 0; i < MAX_NUMNODES; ++i) {
442#ifdef CONFIG_HIGHMEM
443 unsigned long end_pfn = node_lowmem_end_pfn[i];
444#else
445 unsigned long end_pfn = node_end_pfn[i];
446#endif
447 unsigned long end_huge_pfn = 0;
448
449 /* Pre-shatter the last huge page to allow per-cpu pages. */
450 if (kdata_huge)
451 end_huge_pfn = end_pfn - (HPAGE_SIZE >> PAGE_SHIFT);
452
453 pfn = node_start_pfn[i];
454
455 /* Allocate enough memory to hold L2 page tables for node. */
456 init_prealloc_ptes(i, end_pfn - pfn);
457
458 address = (unsigned long) pfn_to_kaddr(pfn);
459 while (pfn < end_pfn) {
460 BUG_ON(address & (HPAGE_SIZE-1));
461 pmd = get_pmd(pgtables, address);
462 pte = get_prealloc_pte(pfn);
463 if (pfn < end_huge_pfn) {
464 pgprot_t prot = init_pgprot(address);
465 *(pte_t *)pmd = pte_mkhuge(pfn_pte(pfn, prot));
466 for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
467 pfn++, pte_ofs++, address += PAGE_SIZE)
468 pte[pte_ofs] = pfn_pte(pfn, prot);
469 } else {
470 if (kdata_huge)
471 printk(KERN_DEBUG "pre-shattered huge page at %#lx\n",
472 address);
473 for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
474 pfn++, pte_ofs++, address += PAGE_SIZE) {
475 pgprot_t prot = init_pgprot(address);
476 pte[pte_ofs] = pfn_pte(pfn, prot);
477 }
478 assign_pte(pmd, pte);
479 }
480 }
481 }
482
483 /*
484 * Set or check ktext_map now that we have cpu_possible_mask
485 * and kstripe_mask to work with.
486 */
487 if (ktext_all)
488 cpumask_copy(&ktext_mask, cpu_possible_mask);
489 else if (ktext_nondataplane)
490 ktext_mask = kstripe_mask;
491 else if (!cpumask_empty(&ktext_mask)) {
492 /* Sanity-check any mask that was requested */
493 struct cpumask bad;
494 cpumask_andnot(&bad, &ktext_mask, cpu_possible_mask);
495 cpumask_and(&ktext_mask, &ktext_mask, cpu_possible_mask);
496 if (!cpumask_empty(&bad))
497 pr_info("ktext: not using unavailable cpus %*pbl\n",
498 cpumask_pr_args(&bad));
499 if (cpumask_empty(&ktext_mask)) {
500 pr_warn("ktext: no valid cpus; caching on %d\n",
501 smp_processor_id());
502 cpumask_copy(&ktext_mask,
503 cpumask_of(smp_processor_id()));
504 }
505 }
506
507 address = MEM_SV_START;
508 pmd = get_pmd(pgtables, address);
509 pfn = 0; /* code starts at PA 0 */
510 if (ktext_small) {
511 /* Allocate an L2 PTE for the kernel text */
512 int cpu = 0;
513 pgprot_t prot = construct_pgprot(PAGE_KERNEL_EXEC,
514 PAGE_HOME_IMMUTABLE);
515
516 if (ktext_local) {
517 if (ktext_nocache)
518 prot = hv_pte_set_mode(prot,
519 HV_PTE_MODE_UNCACHED);
520 else
521 prot = hv_pte_set_mode(prot,
522 HV_PTE_MODE_CACHE_NO_L3);
523 } else {
524 prot = hv_pte_set_mode(prot,
525 HV_PTE_MODE_CACHE_TILE_L3);
526 cpu = cpumask_first(&ktext_mask);
527
528 prot = ktext_set_nocache(prot);
529 }
530
531 BUG_ON(address != (unsigned long)_text);
532 pte = NULL;
533 for (; address < (unsigned long)_einittext;
534 pfn++, address += PAGE_SIZE) {
535 pte_ofs = pte_index(address);
536 if (pte_ofs == 0) {
537 if (pte)
538 assign_pte(pmd++, pte);
539 pte = alloc_pte();
540 }
541 if (!ktext_local) {
542 prot = set_remote_cache_cpu(prot, cpu);
543 cpu = cpumask_next(cpu, &ktext_mask);
544 if (cpu == NR_CPUS)
545 cpu = cpumask_first(&ktext_mask);
546 }
547 pte[pte_ofs] = pfn_pte(pfn, prot);
548 }
549 if (pte)
550 assign_pte(pmd, pte);
551 } else {
552 pte_t pteval = pfn_pte(0, PAGE_KERNEL_EXEC);
553 pteval = pte_mkhuge(pteval);
554 if (ktext_hash) {
555 pteval = hv_pte_set_mode(pteval,
556 HV_PTE_MODE_CACHE_HASH_L3);
557 pteval = ktext_set_nocache(pteval);
558 } else
559 if (cpumask_weight(&ktext_mask) == 1) {
560 pteval = set_remote_cache_cpu(pteval,
561 cpumask_first(&ktext_mask));
562 pteval = hv_pte_set_mode(pteval,
563 HV_PTE_MODE_CACHE_TILE_L3);
564 pteval = ktext_set_nocache(pteval);
565 } else if (ktext_nocache)
566 pteval = hv_pte_set_mode(pteval,
567 HV_PTE_MODE_UNCACHED);
568 else
569 pteval = hv_pte_set_mode(pteval,
570 HV_PTE_MODE_CACHE_NO_L3);
571 for (; address < (unsigned long)_einittext;
572 pfn += PFN_DOWN(HPAGE_SIZE), address += HPAGE_SIZE)
573 *(pte_t *)(pmd++) = pfn_pte(pfn, pteval);
574 }
575
576 /* Set swapper_pgprot here so it is flushed to memory right away. */
577 swapper_pgprot = init_pgprot((unsigned long)swapper_pg_dir);
578
579 /*
580 * Since we may be changing the caching of the stack and page
581 * table itself, we invoke an assembly helper to do the
582 * following steps:
583 *
584 * - flush the cache so we start with an empty slate
585 * - install pgtables[] as the real page table
586 * - flush the TLB so the new page table takes effect
587 */
588 irqmask = interrupt_mask_save_mask();
589 interrupt_mask_set_mask(-1ULL);
590 rc = flush_and_install_context(__pa(pgtables),
591 init_pgprot((unsigned long)pgtables),
592 __this_cpu_read(current_asid),
593 cpumask_bits(my_cpu_mask));
594 interrupt_mask_restore_mask(irqmask);
595 BUG_ON(rc != 0);
596
597 /* Copy the page table back to the normal swapper_pg_dir. */
598 memcpy(pgd_base, pgtables, sizeof(pgtables));
599 __install_page_table(pgd_base, __this_cpu_read(current_asid),
600 swapper_pgprot);
601
602 /*
603 * We just read swapper_pgprot and thus brought it into the cache,
604 * with its new home & caching mode. When we start the other CPUs,
605 * they're going to reference swapper_pgprot via their initial fake
606 * VA-is-PA mappings, which cache everything locally. At that
607 * time, if it's in our cache with a conflicting home, the
608 * simulator's coherence checker will complain. So, flush it out
609 * of our cache; we're not going to ever use it again anyway.
610 */
611 __insn_finv(&swapper_pgprot);
612}
613
614/*
615 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
616 * is valid. The argument is a physical page number.
617 *
618 * On Tile, the only valid things for which we can just hand out unchecked
619 * PTEs are the kernel code and data. Anything else might change its
620 * homing with time, and we wouldn't know to adjust the /dev/mem PTEs.
621 * Note that init_thread_union is released to heap soon after boot,
622 * so we include it in the init data.
623 *
624 * For TILE-Gx, we might want to consider allowing access to PA
625 * regions corresponding to PCI space, etc.
626 */
627int devmem_is_allowed(unsigned long pagenr)
628{
629 return pagenr < kaddr_to_pfn(_end) &&
630 !(pagenr >= kaddr_to_pfn(&init_thread_union) ||
631 pagenr < kaddr_to_pfn(__init_end)) &&
632 !(pagenr >= kaddr_to_pfn(_sinittext) ||
633 pagenr <= kaddr_to_pfn(_einittext-1));
634}
635
636#ifdef CONFIG_HIGHMEM
637static void __init permanent_kmaps_init(pgd_t *pgd_base)
638{
639 pgd_t *pgd;
640 pud_t *pud;
641 pmd_t *pmd;
642 pte_t *pte;
643 unsigned long vaddr;
644
645 vaddr = PKMAP_BASE;
646 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
647
648 pgd = swapper_pg_dir + pgd_index(vaddr);
649 pud = pud_offset(pgd, vaddr);
650 pmd = pmd_offset(pud, vaddr);
651 pte = pte_offset_kernel(pmd, vaddr);
652 pkmap_page_table = pte;
653}
654#endif /* CONFIG_HIGHMEM */
655
656
657#ifndef CONFIG_64BIT
658static void __init init_free_pfn_range(unsigned long start, unsigned long end)
659{
660 unsigned long pfn;
661 struct page *page = pfn_to_page(start);
662
663 for (pfn = start; pfn < end; ) {
664 /* Optimize by freeing pages in large batches */
665 int order = __ffs(pfn);
666 int count, i;
667 struct page *p;
668
669 if (order >= MAX_ORDER)
670 order = MAX_ORDER-1;
671 count = 1 << order;
672 while (pfn + count > end) {
673 count >>= 1;
674 --order;
675 }
676 for (p = page, i = 0; i < count; ++i, ++p) {
677 __ClearPageReserved(p);
678 /*
679 * Hacky direct set to avoid unnecessary
680 * lock take/release for EVERY page here.
681 */
682 p->_refcount.counter = 0;
683 p->_mapcount.counter = -1;
684 }
685 init_page_count(page);
686 __free_pages(page, order);
687 adjust_managed_page_count(page, count);
688
689 page += count;
690 pfn += count;
691 }
692}
693
694static void __init set_non_bootmem_pages_init(void)
695{
696 struct zone *z;
697 for_each_zone(z) {
698 unsigned long start, end;
699 int nid = z->zone_pgdat->node_id;
700#ifdef CONFIG_HIGHMEM
701 int idx = zone_idx(z);
702#endif
703
704 start = z->zone_start_pfn;
705 end = start + z->spanned_pages;
706 start = max(start, node_free_pfn[nid]);
707 start = max(start, max_low_pfn);
708
709#ifdef CONFIG_HIGHMEM
710 if (idx == ZONE_HIGHMEM)
711 totalhigh_pages += z->spanned_pages;
712#endif
713 if (kdata_huge) {
714 unsigned long percpu_pfn = node_percpu_pfn[nid];
715 if (start < percpu_pfn && end > percpu_pfn)
716 end = percpu_pfn;
717 }
718#ifdef CONFIG_PCI
719 if (start <= pci_reserve_start_pfn &&
720 end > pci_reserve_start_pfn) {
721 if (end > pci_reserve_end_pfn)
722 init_free_pfn_range(pci_reserve_end_pfn, end);
723 end = pci_reserve_start_pfn;
724 }
725#endif
726 init_free_pfn_range(start, end);
727 }
728}
729#endif
730
731/*
732 * paging_init() sets up the page tables - note that all of lowmem is
733 * already mapped by head.S.
734 */
735void __init paging_init(void)
736{
737#ifdef __tilegx__
738 pud_t *pud;
739#endif
740 pgd_t *pgd_base = swapper_pg_dir;
741
742 kernel_physical_mapping_init(pgd_base);
743
744 /* Fixed mappings, only the page table structure has to be created. */
745 page_table_range_init(fix_to_virt(__end_of_fixed_addresses - 1),
746 FIXADDR_TOP, pgd_base);
747
748#ifdef CONFIG_HIGHMEM
749 permanent_kmaps_init(pgd_base);
750#endif
751
752#ifdef __tilegx__
753 /*
754 * Since GX allocates just one pmd_t array worth of vmalloc space,
755 * we go ahead and allocate it statically here, then share it
756 * globally. As a result we don't have to worry about any task
757 * changing init_mm once we get up and running, and there's no
758 * need for e.g. vmalloc_sync_all().
759 */
760 BUILD_BUG_ON(pgd_index(VMALLOC_START) != pgd_index(VMALLOC_END - 1));
761 pud = pud_offset(pgd_base + pgd_index(VMALLOC_START), VMALLOC_START);
762 assign_pmd(pud, alloc_pmd());
763#endif
764}
765
766
767/*
768 * Walk the kernel page tables and derive the page_home() from
769 * the PTEs, so that set_pte() can properly validate the caching
770 * of all PTEs it sees.
771 */
772void __init set_page_homes(void)
773{
774}
775
776static void __init set_max_mapnr_init(void)
777{
778#ifdef CONFIG_FLATMEM
779 max_mapnr = max_low_pfn;
780#endif
781}
782
783void __init mem_init(void)
784{
785 int i;
786#ifndef __tilegx__
787 void *last;
788#endif
789
790#ifdef CONFIG_FLATMEM
791 BUG_ON(!mem_map);
792#endif
793
794#ifdef CONFIG_HIGHMEM
795 /* check that fixmap and pkmap do not overlap */
796 if (PKMAP_ADDR(LAST_PKMAP-1) >= FIXADDR_START) {
797 pr_err("fixmap and kmap areas overlap - this will crash\n");
798 pr_err("pkstart: %lxh pkend: %lxh fixstart %lxh\n",
799 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP-1), FIXADDR_START);
800 BUG();
801 }
802#endif
803
804 set_max_mapnr_init();
805
806 /* this will put all bootmem onto the freelists */
807 free_all_bootmem();
808
809#ifndef CONFIG_64BIT
810 /* count all remaining LOWMEM and give all HIGHMEM to page allocator */
811 set_non_bootmem_pages_init();
812#endif
813
814 mem_init_print_info(NULL);
815
816 /*
817 * In debug mode, dump some interesting memory mappings.
818 */
819#ifdef CONFIG_HIGHMEM
820 printk(KERN_DEBUG " KMAP %#lx - %#lx\n",
821 FIXADDR_START, FIXADDR_TOP + PAGE_SIZE - 1);
822 printk(KERN_DEBUG " PKMAP %#lx - %#lx\n",
823 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP) - 1);
824#endif
825 printk(KERN_DEBUG " VMALLOC %#lx - %#lx\n",
826 _VMALLOC_START, _VMALLOC_END - 1);
827#ifdef __tilegx__
828 for (i = MAX_NUMNODES-1; i >= 0; --i) {
829 struct pglist_data *node = &node_data[i];
830 if (node->node_present_pages) {
831 unsigned long start = (unsigned long)
832 pfn_to_kaddr(node->node_start_pfn);
833 unsigned long end = start +
834 (node->node_present_pages << PAGE_SHIFT);
835 printk(KERN_DEBUG " MEM%d %#lx - %#lx\n",
836 i, start, end - 1);
837 }
838 }
839#else
840 last = high_memory;
841 for (i = MAX_NUMNODES-1; i >= 0; --i) {
842 if ((unsigned long)vbase_map[i] != -1UL) {
843 printk(KERN_DEBUG " LOWMEM%d %#lx - %#lx\n",
844 i, (unsigned long) (vbase_map[i]),
845 (unsigned long) (last-1));
846 last = vbase_map[i];
847 }
848 }
849#endif
850
851#ifndef __tilegx__
852 /*
853 * Convert from using one lock for all atomic operations to
854 * one per cpu.
855 */
856 __init_atomic_per_cpu();
857#endif
858}
859
860/*
861 * this is for the non-NUMA, single node SMP system case.
862 * Specifically, in the case of x86, we will always add
863 * memory to the highmem for now.
864 */
865#ifndef CONFIG_NEED_MULTIPLE_NODES
866int arch_add_memory(u64 start, u64 size, bool for_device)
867{
868 struct pglist_data *pgdata = &contig_page_data;
869 struct zone *zone = pgdata->node_zones + MAX_NR_ZONES-1;
870 unsigned long start_pfn = start >> PAGE_SHIFT;
871 unsigned long nr_pages = size >> PAGE_SHIFT;
872
873 return __add_pages(zone, start_pfn, nr_pages);
874}
875
876int remove_memory(u64 start, u64 size)
877{
878 return -EINVAL;
879}
880
881#ifdef CONFIG_MEMORY_HOTREMOVE
882int arch_remove_memory(u64 start, u64 size)
883{
884 /* TODO */
885 return -EBUSY;
886}
887#endif
888#endif
889
890struct kmem_cache *pgd_cache;
891
892void __init pgtable_cache_init(void)
893{
894 pgd_cache = kmem_cache_create("pgd", SIZEOF_PGD, SIZEOF_PGD, 0, NULL);
895 if (!pgd_cache)
896 panic("pgtable_cache_init(): Cannot create pgd cache");
897}
898
899static long __ro_after_init initfree = 1;
900static bool __ro_after_init set_initfree_done;
901
902/* Select whether to free (1) or mark unusable (0) the __init pages. */
903static int __init set_initfree(char *str)
904{
905 long val;
906 if (kstrtol(str, 0, &val) == 0) {
907 set_initfree_done = true;
908 initfree = val;
909 pr_info("initfree: %s free init pages\n",
910 initfree ? "will" : "won't");
911 }
912 return 1;
913}
914__setup("initfree=", set_initfree);
915
916static void free_init_pages(char *what, unsigned long begin, unsigned long end)
917{
918 unsigned long addr = (unsigned long) begin;
919
920 /* Prefer user request first */
921 if (!set_initfree_done) {
922 if (debug_pagealloc_enabled())
923 initfree = 0;
924 }
925 if (kdata_huge && !initfree) {
926 pr_warn("Warning: ignoring initfree=0: incompatible with kdata=huge\n");
927 initfree = 1;
928 }
929 end = (end + PAGE_SIZE - 1) & PAGE_MASK;
930 local_flush_tlb_pages(NULL, begin, PAGE_SIZE, end - begin);
931 for (addr = begin; addr < end; addr += PAGE_SIZE) {
932 /*
933 * Note we just reset the home here directly in the
934 * page table. We know this is safe because our caller
935 * just flushed the caches on all the other cpus,
936 * and they won't be touching any of these pages.
937 */
938 int pfn = kaddr_to_pfn((void *)addr);
939 struct page *page = pfn_to_page(pfn);
940 pte_t *ptep = virt_to_kpte(addr);
941 if (!initfree) {
942 /*
943 * If debugging page accesses then do not free
944 * this memory but mark them not present - any
945 * buggy init-section access will create a
946 * kernel page fault:
947 */
948 pte_clear(&init_mm, addr, ptep);
949 continue;
950 }
951 if (pte_huge(*ptep))
952 BUG_ON(!kdata_huge);
953 else
954 set_pte_at(&init_mm, addr, ptep,
955 pfn_pte(pfn, PAGE_KERNEL));
956 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
957 free_reserved_page(page);
958 }
959 pr_info("Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
960}
961
962void free_initmem(void)
963{
964 const unsigned long text_delta = MEM_SV_START - PAGE_OFFSET;
965
966 /*
967 * Evict the cache on all cores to avoid incoherence.
968 * We are guaranteed that no one will touch the init pages any more.
969 */
970 homecache_evict(&cpu_cacheable_map);
971
972 /* Free the data pages that we won't use again after init. */
973 free_init_pages("unused kernel data",
974 (unsigned long)__init_begin,
975 (unsigned long)__init_end);
976
977 /*
978 * Free the pages mapped from 0xc0000000 that correspond to code
979 * pages from MEM_SV_START that we won't use again after init.
980 */
981 free_init_pages("unused kernel text",
982 (unsigned long)_sinittext - text_delta,
983 (unsigned long)_einittext - text_delta);
984 /* Do a global TLB flush so everyone sees the changes. */
985 flush_tlb_all();
986}