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 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
9 *
10 * Derived from "arch/i386/mm/init.c"
11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
17 *
18 */
19
20 #include <linux/export.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/string.h>
25 #include <linux/gfp.h>
26 #include <linux/types.h>
27 #include <linux/mm.h>
28 #include <linux/stddef.h>
29 #include <linux/init.h>
30 #include <linux/bootmem.h>
31 #include <linux/highmem.h>
32 #include <linux/initrd.h>
33 #include <linux/pagemap.h>
34 #include <linux/suspend.h>
35 #include <linux/memblock.h>
36 #include <linux/hugetlb.h>
37 #include <linux/slab.h>
38 #include <linux/vmalloc.h>
39
40 #include <asm/pgalloc.h>
41 #include <asm/prom.h>
42 #include <asm/io.h>
43 #include <asm/mmu_context.h>
44 #include <asm/pgtable.h>
45 #include <asm/mmu.h>
46 #include <asm/smp.h>
47 #include <asm/machdep.h>
48 #include <asm/btext.h>
49 #include <asm/tlb.h>
50 #include <asm/sections.h>
51 #include <asm/sparsemem.h>
52 #include <asm/vdso.h>
53 #include <asm/fixmap.h>
54 #include <asm/swiotlb.h>
55 #include <asm/rtas.h>
56
57 #include "mmu_decl.h"
58
59 #ifndef CPU_FTR_COHERENT_ICACHE
60 #define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
61 #define CPU_FTR_NOEXECUTE 0
62 #endif
63
64 unsigned long long memory_limit;
65 bool init_mem_is_free;
66
67 #ifdef CONFIG_HIGHMEM
68 pte_t *kmap_pte;
69 EXPORT_SYMBOL(kmap_pte);
70 pgprot_t kmap_prot;
71 EXPORT_SYMBOL(kmap_prot);
72
virt_to_kpte(unsigned long vaddr)73 static inline pte_t *virt_to_kpte(unsigned long vaddr)
74 {
75 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
76 vaddr), vaddr), vaddr);
77 }
78 #endif
79
page_is_ram(unsigned long pfn)80 int page_is_ram(unsigned long pfn)
81 {
82 #ifndef CONFIG_PPC64 /* XXX for now */
83 return pfn < max_pfn;
84 #else
85 unsigned long paddr = (pfn << PAGE_SHIFT);
86 struct memblock_region *reg;
87
88 for_each_memblock(memory, reg)
89 if (paddr >= reg->base && paddr < (reg->base + reg->size))
90 return 1;
91 return 0;
92 #endif
93 }
94
phys_mem_access_prot(struct file * file,unsigned long pfn,unsigned long size,pgprot_t vma_prot)95 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
96 unsigned long size, pgprot_t vma_prot)
97 {
98 if (ppc_md.phys_mem_access_prot)
99 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
100
101 if (!page_is_ram(pfn))
102 vma_prot = pgprot_noncached(vma_prot);
103
104 return vma_prot;
105 }
106 EXPORT_SYMBOL(phys_mem_access_prot);
107
108 #ifdef CONFIG_MEMORY_HOTPLUG
109
110 #ifdef CONFIG_NUMA
memory_add_physaddr_to_nid(u64 start)111 int memory_add_physaddr_to_nid(u64 start)
112 {
113 return hot_add_scn_to_nid(start);
114 }
115 #endif
116
arch_add_memory(int nid,u64 start,u64 size,bool for_device)117 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
118 {
119 struct pglist_data *pgdata;
120 struct zone *zone;
121 unsigned long start_pfn = start >> PAGE_SHIFT;
122 unsigned long nr_pages = size >> PAGE_SHIFT;
123
124 pgdata = NODE_DATA(nid);
125
126 start = (unsigned long)__va(start);
127 if (create_section_mapping(start, start + size))
128 return -EINVAL;
129
130 /* this should work for most non-highmem platforms */
131 zone = pgdata->node_zones +
132 zone_for_memory(nid, start, size, 0, for_device);
133
134 return __add_pages(nid, zone, start_pfn, nr_pages);
135 }
136
137 #ifdef CONFIG_MEMORY_HOTREMOVE
arch_remove_memory(u64 start,u64 size)138 int arch_remove_memory(u64 start, u64 size)
139 {
140 unsigned long start_pfn = start >> PAGE_SHIFT;
141 unsigned long nr_pages = size >> PAGE_SHIFT;
142 struct zone *zone;
143 int ret;
144
145 zone = page_zone(pfn_to_page(start_pfn));
146 ret = __remove_pages(zone, start_pfn, nr_pages);
147 if (ret)
148 return ret;
149
150 /* Remove htab bolted mappings for this section of memory */
151 start = (unsigned long)__va(start);
152 ret = remove_section_mapping(start, start + size);
153
154 /* Ensure all vmalloc mappings are flushed in case they also
155 * hit that section of memory
156 */
157 vm_unmap_aliases();
158
159 return ret;
160 }
161 #endif
162 #endif /* CONFIG_MEMORY_HOTPLUG */
163
164 /*
165 * walk_memory_resource() needs to make sure there is no holes in a given
166 * memory range. PPC64 does not maintain the memory layout in /proc/iomem.
167 * Instead it maintains it in memblock.memory structures. Walk through the
168 * memory regions, find holes and callback for contiguous regions.
169 */
170 int
walk_system_ram_range(unsigned long start_pfn,unsigned long nr_pages,void * arg,int (* func)(unsigned long,unsigned long,void *))171 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
172 void *arg, int (*func)(unsigned long, unsigned long, void *))
173 {
174 struct memblock_region *reg;
175 unsigned long end_pfn = start_pfn + nr_pages;
176 unsigned long tstart, tend;
177 int ret = -1;
178
179 for_each_memblock(memory, reg) {
180 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
181 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
182 if (tstart >= tend)
183 continue;
184 ret = (*func)(tstart, tend - tstart, arg);
185 if (ret)
186 break;
187 }
188 return ret;
189 }
190 EXPORT_SYMBOL_GPL(walk_system_ram_range);
191
192 #ifndef CONFIG_NEED_MULTIPLE_NODES
initmem_init(void)193 void __init initmem_init(void)
194 {
195 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
196 min_low_pfn = MEMORY_START >> PAGE_SHIFT;
197 #ifdef CONFIG_HIGHMEM
198 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
199 #endif
200
201 /* Place all memblock_regions in the same node and merge contiguous
202 * memblock_regions
203 */
204 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
205
206 /* XXX need to clip this if using highmem? */
207 sparse_memory_present_with_active_regions(0);
208 sparse_init();
209 }
210
211 /* mark pages that don't exist as nosave */
mark_nonram_nosave(void)212 static int __init mark_nonram_nosave(void)
213 {
214 struct memblock_region *reg, *prev = NULL;
215
216 for_each_memblock(memory, reg) {
217 if (prev &&
218 memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
219 register_nosave_region(memblock_region_memory_end_pfn(prev),
220 memblock_region_memory_base_pfn(reg));
221 prev = reg;
222 }
223 return 0;
224 }
225 #else /* CONFIG_NEED_MULTIPLE_NODES */
mark_nonram_nosave(void)226 static int __init mark_nonram_nosave(void)
227 {
228 return 0;
229 }
230 #endif
231
232 static bool zone_limits_final;
233
234 static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
235 [0 ... MAX_NR_ZONES - 1] = ~0UL
236 };
237
238 /*
239 * Restrict the specified zone and all more restrictive zones
240 * to be below the specified pfn. May not be called after
241 * paging_init().
242 */
limit_zone_pfn(enum zone_type zone,unsigned long pfn_limit)243 void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
244 {
245 int i;
246
247 if (WARN_ON(zone_limits_final))
248 return;
249
250 for (i = zone; i >= 0; i--) {
251 if (max_zone_pfns[i] > pfn_limit)
252 max_zone_pfns[i] = pfn_limit;
253 }
254 }
255
256 /*
257 * Find the least restrictive zone that is entirely below the
258 * specified pfn limit. Returns < 0 if no suitable zone is found.
259 *
260 * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
261 * systems -- the DMA limit can be higher than any possible real pfn.
262 */
dma_pfn_limit_to_zone(u64 pfn_limit)263 int dma_pfn_limit_to_zone(u64 pfn_limit)
264 {
265 enum zone_type top_zone = ZONE_NORMAL;
266 int i;
267
268 #ifdef CONFIG_HIGHMEM
269 top_zone = ZONE_HIGHMEM;
270 #endif
271
272 for (i = top_zone; i >= 0; i--) {
273 if (max_zone_pfns[i] <= pfn_limit)
274 return i;
275 }
276
277 return -EPERM;
278 }
279
280 /*
281 * paging_init() sets up the page tables - in fact we've already done this.
282 */
paging_init(void)283 void __init paging_init(void)
284 {
285 unsigned long long total_ram = memblock_phys_mem_size();
286 phys_addr_t top_of_ram = memblock_end_of_DRAM();
287 enum zone_type top_zone;
288
289 #ifdef CONFIG_PPC32
290 unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
291 unsigned long end = __fix_to_virt(FIX_HOLE);
292
293 for (; v < end; v += PAGE_SIZE)
294 map_page(v, 0, 0); /* XXX gross */
295 #endif
296
297 #ifdef CONFIG_HIGHMEM
298 map_page(PKMAP_BASE, 0, 0); /* XXX gross */
299 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
300
301 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
302 kmap_prot = PAGE_KERNEL;
303 #endif /* CONFIG_HIGHMEM */
304
305 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
306 (unsigned long long)top_of_ram, total_ram);
307 printk(KERN_DEBUG "Memory hole size: %ldMB\n",
308 (long int)((top_of_ram - total_ram) >> 20));
309
310 #ifdef CONFIG_HIGHMEM
311 top_zone = ZONE_HIGHMEM;
312 limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
313 #else
314 top_zone = ZONE_NORMAL;
315 #endif
316
317 limit_zone_pfn(top_zone, top_of_ram >> PAGE_SHIFT);
318 zone_limits_final = true;
319 free_area_init_nodes(max_zone_pfns);
320
321 mark_nonram_nosave();
322 }
323
mem_init(void)324 void __init mem_init(void)
325 {
326 /*
327 * book3s is limited to 16 page sizes due to encoding this in
328 * a 4-bit field for slices.
329 */
330 BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
331
332 #ifdef CONFIG_SWIOTLB
333 /*
334 * Some platforms (e.g. 85xx) limit DMA-able memory way below
335 * 4G. We force memblock to bottom-up mode to ensure that the
336 * memory allocated in swiotlb_init() is DMA-able.
337 * As it's the last memblock allocation, no need to reset it
338 * back to to-down.
339 */
340 memblock_set_bottom_up(true);
341 swiotlb_init(0);
342 #endif
343
344 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
345 set_max_mapnr(max_pfn);
346 free_all_bootmem();
347
348 #ifdef CONFIG_HIGHMEM
349 {
350 unsigned long pfn, highmem_mapnr;
351
352 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
353 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
354 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
355 struct page *page = pfn_to_page(pfn);
356 if (!memblock_is_reserved(paddr))
357 free_highmem_page(page);
358 }
359 }
360 #endif /* CONFIG_HIGHMEM */
361
362 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
363 /*
364 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
365 * functions.... do it here for the non-smp case.
366 */
367 per_cpu(next_tlbcam_idx, smp_processor_id()) =
368 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
369 #endif
370
371 mem_init_print_info(NULL);
372 #ifdef CONFIG_PPC32
373 pr_info("Kernel virtual memory layout:\n");
374 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
375 #ifdef CONFIG_HIGHMEM
376 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
377 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
378 #endif /* CONFIG_HIGHMEM */
379 #ifdef CONFIG_NOT_COHERENT_CACHE
380 pr_info(" * 0x%08lx..0x%08lx : consistent mem\n",
381 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
382 #endif /* CONFIG_NOT_COHERENT_CACHE */
383 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
384 ioremap_bot, IOREMAP_TOP);
385 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
386 VMALLOC_START, VMALLOC_END);
387 #endif /* CONFIG_PPC32 */
388 }
389
free_initmem(void)390 void free_initmem(void)
391 {
392 ppc_md.progress = ppc_printk_progress;
393 init_mem_is_free = true;
394 free_initmem_default(POISON_FREE_INITMEM);
395 }
396
397 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)398 void __init free_initrd_mem(unsigned long start, unsigned long end)
399 {
400 free_reserved_area((void *)start, (void *)end, -1, "initrd");
401 }
402 #endif
403
404 /*
405 * This is called when a page has been modified by the kernel.
406 * It just marks the page as not i-cache clean. We do the i-cache
407 * flush later when the page is given to a user process, if necessary.
408 */
flush_dcache_page(struct page * page)409 void flush_dcache_page(struct page *page)
410 {
411 if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
412 return;
413 /* avoid an atomic op if possible */
414 if (test_bit(PG_arch_1, &page->flags))
415 clear_bit(PG_arch_1, &page->flags);
416 }
417 EXPORT_SYMBOL(flush_dcache_page);
418
flush_dcache_icache_page(struct page * page)419 void flush_dcache_icache_page(struct page *page)
420 {
421 #ifdef CONFIG_HUGETLB_PAGE
422 if (PageCompound(page)) {
423 flush_dcache_icache_hugepage(page);
424 return;
425 }
426 #endif
427 #if defined(CONFIG_8xx) || defined(CONFIG_PPC64)
428 /* On 8xx there is no need to kmap since highmem is not supported */
429 __flush_dcache_icache(page_address(page));
430 #else
431 if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
432 void *start = kmap_atomic(page);
433 __flush_dcache_icache(start);
434 kunmap_atomic(start);
435 } else {
436 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
437 }
438 #endif
439 }
440 EXPORT_SYMBOL(flush_dcache_icache_page);
441
clear_user_page(void * page,unsigned long vaddr,struct page * pg)442 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
443 {
444 clear_page(page);
445
446 /*
447 * We shouldn't have to do this, but some versions of glibc
448 * require it (ld.so assumes zero filled pages are icache clean)
449 * - Anton
450 */
451 flush_dcache_page(pg);
452 }
453 EXPORT_SYMBOL(clear_user_page);
454
copy_user_page(void * vto,void * vfrom,unsigned long vaddr,struct page * pg)455 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
456 struct page *pg)
457 {
458 copy_page(vto, vfrom);
459
460 /*
461 * We should be able to use the following optimisation, however
462 * there are two problems.
463 * Firstly a bug in some versions of binutils meant PLT sections
464 * were not marked executable.
465 * Secondly the first word in the GOT section is blrl, used
466 * to establish the GOT address. Until recently the GOT was
467 * not marked executable.
468 * - Anton
469 */
470 #if 0
471 if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
472 return;
473 #endif
474
475 flush_dcache_page(pg);
476 }
477
flush_icache_user_range(struct vm_area_struct * vma,struct page * page,unsigned long addr,int len)478 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
479 unsigned long addr, int len)
480 {
481 unsigned long maddr;
482
483 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
484 flush_icache_range(maddr, maddr + len);
485 kunmap(page);
486 }
487 EXPORT_SYMBOL(flush_icache_user_range);
488
489 /*
490 * This is called at the end of handling a user page fault, when the
491 * fault has been handled by updating a PTE in the linux page tables.
492 * We use it to preload an HPTE into the hash table corresponding to
493 * the updated linux PTE.
494 *
495 * This must always be called with the pte lock held.
496 */
update_mmu_cache(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)497 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
498 pte_t *ptep)
499 {
500 #ifdef CONFIG_PPC_STD_MMU
501 /*
502 * We don't need to worry about _PAGE_PRESENT here because we are
503 * called with either mm->page_table_lock held or ptl lock held
504 */
505 unsigned long access = 0, trap;
506
507 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
508 if (!pte_young(*ptep) || address >= TASK_SIZE)
509 return;
510
511 /* We try to figure out if we are coming from an instruction
512 * access fault and pass that down to __hash_page so we avoid
513 * double-faulting on execution of fresh text. We have to test
514 * for regs NULL since init will get here first thing at boot
515 *
516 * We also avoid filling the hash if not coming from a fault
517 */
518 if (current->thread.regs == NULL)
519 return;
520 trap = TRAP(current->thread.regs);
521 if (trap == 0x400)
522 access |= _PAGE_EXEC;
523 else if (trap != 0x300)
524 return;
525 hash_preload(vma->vm_mm, address, access, trap);
526 #endif /* CONFIG_PPC_STD_MMU */
527 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
528 && defined(CONFIG_HUGETLB_PAGE)
529 if (is_vm_hugetlb_page(vma))
530 book3e_hugetlb_preload(vma, address, *ptep);
531 #endif
532 }
533
534 /*
535 * System memory should not be in /proc/iomem but various tools expect it
536 * (eg kdump).
537 */
add_system_ram_resources(void)538 static int __init add_system_ram_resources(void)
539 {
540 struct memblock_region *reg;
541
542 for_each_memblock(memory, reg) {
543 struct resource *res;
544 unsigned long base = reg->base;
545 unsigned long size = reg->size;
546
547 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
548 WARN_ON(!res);
549
550 if (res) {
551 res->name = "System RAM";
552 res->start = base;
553 res->end = base + size - 1;
554 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
555 WARN_ON(request_resource(&iomem_resource, res) < 0);
556 }
557 }
558
559 return 0;
560 }
561 subsys_initcall(add_system_ram_resources);
562
563 #ifdef CONFIG_STRICT_DEVMEM
564 /*
565 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
566 * is valid. The argument is a physical page number.
567 *
568 * Access has to be given to non-kernel-ram areas as well, these contain the
569 * PCI mmio resources as well as potential bios/acpi data regions.
570 */
devmem_is_allowed(unsigned long pfn)571 int devmem_is_allowed(unsigned long pfn)
572 {
573 if (iomem_is_exclusive(PFN_PHYS(pfn)))
574 return 0;
575 if (!page_is_ram(pfn))
576 return 1;
577 if (page_is_rtas_user_buf(pfn))
578 return 1;
579 return 0;
580 }
581 #endif /* CONFIG_STRICT_DEVMEM */
582