summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/mm/mem.c
blob: cba29131bccc5e9a51807ddda420a3e8b20220d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 */

#include <linux/export.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/suspend.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/memremap.h>

#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/btext.h>
#include <asm/tlb.h>
#include <asm/sections.h>
#include <asm/sparsemem.h>
#include <asm/vdso.h>
#include <asm/fixmap.h>
#include <asm/swiotlb.h>
#include <asm/rtas.h>

#include <mm/mmu_decl.h>

#ifndef CPU_FTR_COHERENT_ICACHE
#define CPU_FTR_COHERENT_ICACHE	0	/* XXX for now */
#define CPU_FTR_NOEXECUTE	0
#endif

unsigned long long memory_limit;
bool init_mem_is_free;

#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
EXPORT_SYMBOL(kmap_pte);
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);

static inline pte_t *virt_to_kpte(unsigned long vaddr)
{
	return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
			vaddr), vaddr), vaddr);
}
#endif

pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
			      unsigned long size, pgprot_t vma_prot)
{
	if (ppc_md.phys_mem_access_prot)
		return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);

	if (!page_is_ram(pfn))
		vma_prot = pgprot_noncached(vma_prot);

	return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);

#ifdef CONFIG_MEMORY_HOTPLUG

#ifdef CONFIG_NUMA
int memory_add_physaddr_to_nid(u64 start)
{
	return hot_add_scn_to_nid(start);
}
#endif

int __weak create_section_mapping(unsigned long start, unsigned long end, int nid)
{
	return -ENODEV;
}

int __weak remove_section_mapping(unsigned long start, unsigned long end)
{
	return -ENODEV;
}

int __ref arch_add_memory(int nid, u64 start, u64 size,
			struct mhp_restrictions *restrictions)
{
	unsigned long start_pfn = start >> PAGE_SHIFT;
	unsigned long nr_pages = size >> PAGE_SHIFT;
	int rc;

	resize_hpt_for_hotplug(memblock_phys_mem_size());

	start = (unsigned long)__va(start);
	rc = create_section_mapping(start, start + size, nid);
	if (rc) {
		pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
			start, start + size, rc);
		return -EFAULT;
	}
	flush_inval_dcache_range(start, start + size);

	return __add_pages(nid, start_pfn, nr_pages, restrictions);
}

#ifdef CONFIG_MEMORY_HOTREMOVE
void __ref arch_remove_memory(int nid, u64 start, u64 size,
			     struct vmem_altmap *altmap)
{
	unsigned long start_pfn = start >> PAGE_SHIFT;
	unsigned long nr_pages = size >> PAGE_SHIFT;
	struct page *page;
	int ret;

	/*
	 * If we have an altmap then we need to skip over any reserved PFNs
	 * when querying the zone.
	 */
	page = pfn_to_page(start_pfn);
	if (altmap)
		page += vmem_altmap_offset(altmap);

	__remove_pages(page_zone(page), start_pfn, nr_pages, altmap);

	/* Remove htab bolted mappings for this section of memory */
	start = (unsigned long)__va(start);
	flush_inval_dcache_range(start, start + size);
	ret = remove_section_mapping(start, start + size);
	WARN_ON_ONCE(ret);

	/* Ensure all vmalloc mappings are flushed in case they also
	 * hit that section of memory
	 */
	vm_unmap_aliases();

	if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
		pr_warn("Hash collision while resizing HPT\n");
}
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */

#ifndef CONFIG_NEED_MULTIPLE_NODES
void __init mem_topology_setup(void)
{
	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
	max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
#endif

	/* Place all memblock_regions in the same node and merge contiguous
	 * memblock_regions
	 */
	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
}

void __init initmem_init(void)
{
	/* XXX need to clip this if using highmem? */
	sparse_memory_present_with_active_regions(0);
	sparse_init();
}

/* mark pages that don't exist as nosave */
static int __init mark_nonram_nosave(void)
{
	struct memblock_region *reg, *prev = NULL;

	for_each_memblock(memory, reg) {
		if (prev &&
		    memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
			register_nosave_region(memblock_region_memory_end_pfn(prev),
					       memblock_region_memory_base_pfn(reg));
		prev = reg;
	}
	return 0;
}
#else /* CONFIG_NEED_MULTIPLE_NODES */
static int __init mark_nonram_nosave(void)
{
	return 0;
}
#endif

/*
 * Zones usage:
 *
 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
 * everything else. GFP_DMA32 page allocations automatically fall back to
 * ZONE_DMA.
 *
 * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to
 * inform the generic DMA mapping code.  32-bit only devices (if not handled
 * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get
 * otherwise served by ZONE_DMA.
 */
static unsigned long max_zone_pfns[MAX_NR_ZONES];

/*
 * paging_init() sets up the page tables - in fact we've already done this.
 */
void __init paging_init(void)
{
	unsigned long long total_ram = memblock_phys_mem_size();
	phys_addr_t top_of_ram = memblock_end_of_DRAM();

#ifdef CONFIG_PPC32
	unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
	unsigned long end = __fix_to_virt(FIX_HOLE);

	for (; v < end; v += PAGE_SIZE)
		map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
#endif

#ifdef CONFIG_HIGHMEM
	map_kernel_page(PKMAP_BASE, 0, __pgprot(0));	/* XXX gross */
	pkmap_page_table = virt_to_kpte(PKMAP_BASE);

	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
	kmap_prot = PAGE_KERNEL;
#endif /* CONFIG_HIGHMEM */

	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
	       (unsigned long long)top_of_ram, total_ram);
	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
	       (long int)((top_of_ram - total_ram) >> 20));

#ifdef CONFIG_ZONE_DMA
	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT);
#endif
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
	max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
#endif

	free_area_init_nodes(max_zone_pfns);

	mark_nonram_nosave();
}

void __init mem_init(void)
{
	/*
	 * book3s is limited to 16 page sizes due to encoding this in
	 * a 4-bit field for slices.
	 */
	BUILD_BUG_ON(MMU_PAGE_COUNT > 16);

#ifdef CONFIG_SWIOTLB
	swiotlb_init(0);
#endif

	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
	set_max_mapnr(max_pfn);
	memblock_free_all();

#ifdef CONFIG_HIGHMEM
	{
		unsigned long pfn, highmem_mapnr;

		highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
		for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
			phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
			struct page *page = pfn_to_page(pfn);
			if (!memblock_is_reserved(paddr))
				free_highmem_page(page);
		}
	}
#endif /* CONFIG_HIGHMEM */

#if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
	/*
	 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
	 * functions.... do it here for the non-smp case.
	 */
	per_cpu(next_tlbcam_idx, smp_processor_id()) =
		(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
#endif

	mem_init_print_info(NULL);
#ifdef CONFIG_PPC32
	pr_info("Kernel virtual memory layout:\n");
#ifdef CONFIG_KASAN
	pr_info("  * 0x%08lx..0x%08lx  : kasan shadow mem\n",
		KASAN_SHADOW_START, KASAN_SHADOW_END);
#endif
	pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
#ifdef CONFIG_HIGHMEM
	pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
		PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
#endif /* CONFIG_HIGHMEM */
#ifdef CONFIG_NOT_COHERENT_CACHE
	pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
		IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
#endif /* CONFIG_NOT_COHERENT_CACHE */
	pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
		ioremap_bot, IOREMAP_TOP);
	pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
		VMALLOC_START, VMALLOC_END);
#endif /* CONFIG_PPC32 */
}

void free_initmem(void)
{
	ppc_md.progress = ppc_printk_progress;
	mark_initmem_nx();
	init_mem_is_free = true;
	free_initmem_default(POISON_FREE_INITMEM);
}

/*
 * This is called when a page has been modified by the kernel.
 * It just marks the page as not i-cache clean.  We do the i-cache
 * flush later when the page is given to a user process, if necessary.
 */
void flush_dcache_page(struct page *page)
{
	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
		return;
	/* avoid an atomic op if possible */
	if (test_bit(PG_arch_1, &page->flags))
		clear_bit(PG_arch_1, &page->flags);
}
EXPORT_SYMBOL(flush_dcache_page);

void flush_dcache_icache_page(struct page *page)
{
#ifdef CONFIG_HUGETLB_PAGE
	if (PageCompound(page)) {
		flush_dcache_icache_hugepage(page);
		return;
	}
#endif
#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
	/* On 8xx there is no need to kmap since highmem is not supported */
	__flush_dcache_icache(page_address(page));
#else
	if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
		void *start = kmap_atomic(page);
		__flush_dcache_icache(start);
		kunmap_atomic(start);
	} else {
		__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
	}
#endif
}
EXPORT_SYMBOL(flush_dcache_icache_page);

void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
	clear_page(page);

	/*
	 * We shouldn't have to do this, but some versions of glibc
	 * require it (ld.so assumes zero filled pages are icache clean)
	 * - Anton
	 */
	flush_dcache_page(pg);
}
EXPORT_SYMBOL(clear_user_page);

void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
		    struct page *pg)
{
	copy_page(vto, vfrom);

	/*
	 * We should be able to use the following optimisation, however
	 * there are two problems.
	 * Firstly a bug in some versions of binutils meant PLT sections
	 * were not marked executable.
	 * Secondly the first word in the GOT section is blrl, used
	 * to establish the GOT address. Until recently the GOT was
	 * not marked executable.
	 * - Anton
	 */
#if 0
	if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
		return;
#endif

	flush_dcache_page(pg);
}

void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
			     unsigned long addr, int len)
{
	unsigned long maddr;

	maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
	flush_icache_range(maddr, maddr + len);
	kunmap(page);
}
EXPORT_SYMBOL(flush_icache_user_range);

/*
 * This is called at the end of handling a user page fault, when the
 * fault has been handled by updating a PTE in the linux page tables.
 * We use it to preload an HPTE into the hash table corresponding to
 * the updated linux PTE.
 * 
 * This must always be called with the pte lock held.
 */
void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
		      pte_t *ptep)
{
#ifdef CONFIG_PPC_BOOK3S
	/*
	 * We don't need to worry about _PAGE_PRESENT here because we are
	 * called with either mm->page_table_lock held or ptl lock held
	 */
	unsigned long trap;
	bool is_exec;

	if (radix_enabled()) {
		prefetch((void *)address);
		return;
	}

	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
	if (!pte_young(*ptep) || address >= TASK_SIZE)
		return;

	/* We try to figure out if we are coming from an instruction
	 * access fault and pass that down to __hash_page so we avoid
	 * double-faulting on execution of fresh text. We have to test
	 * for regs NULL since init will get here first thing at boot
	 *
	 * We also avoid filling the hash if not coming from a fault
	 */

	trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
	switch (trap) {
	case 0x300:
		is_exec = false;
		break;
	case 0x400:
		is_exec = true;
		break;
	default:
		return;
	}

	hash_preload(vma->vm_mm, address, is_exec, trap);
#endif /* CONFIG_PPC_BOOK3S */
#if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
	&& defined(CONFIG_HUGETLB_PAGE)
	if (is_vm_hugetlb_page(vma))
		book3e_hugetlb_preload(vma, address, *ptep);
#endif
}

/*
 * System memory should not be in /proc/iomem but various tools expect it
 * (eg kdump).
 */
static int __init add_system_ram_resources(void)
{
	struct memblock_region *reg;

	for_each_memblock(memory, reg) {
		struct resource *res;
		unsigned long base = reg->base;
		unsigned long size = reg->size;

		res = kzalloc(sizeof(struct resource), GFP_KERNEL);
		WARN_ON(!res);

		if (res) {
			res->name = "System RAM";
			res->start = base;
			res->end = base + size - 1;
			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
			WARN_ON(request_resource(&iomem_resource, res) < 0);
		}
	}

	return 0;
}
subsys_initcall(add_system_ram_resources);

#ifdef CONFIG_STRICT_DEVMEM
/*
 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
 * is valid. The argument is a physical page number.
 *
 * Access has to be given to non-kernel-ram areas as well, these contain the
 * PCI mmio resources as well as potential bios/acpi data regions.
 */
int devmem_is_allowed(unsigned long pfn)
{
	if (page_is_rtas_user_buf(pfn))
		return 1;
	if (iomem_is_exclusive(PFN_PHYS(pfn)))
		return 0;
	if (!page_is_ram(pfn))
		return 1;
	return 0;
}
#endif /* CONFIG_STRICT_DEVMEM */

/*
 * This is defined in kernel/resource.c but only powerpc needs to export it, for
 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
 */
EXPORT_SYMBOL_GPL(walk_system_ram_range);