arm64: add support for kernel ASLR
[linux-2.6-block.git] / arch / arm64 / mm / init.c
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1/*
2 * Based on arch/arm/mm/init.c
3 *
4 * Copyright (C) 1995-2005 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/kernel.h>
21#include <linux/export.h>
22#include <linux/errno.h>
23#include <linux/swap.h>
24#include <linux/init.h>
25#include <linux/bootmem.h>
26#include <linux/mman.h>
27#include <linux/nodemask.h>
28#include <linux/initrd.h>
29#include <linux/gfp.h>
30#include <linux/memblock.h>
31#include <linux/sort.h>
32#include <linux/of_fdt.h>
19e7640d 33#include <linux/dma-mapping.h>
6ac2104d 34#include <linux/dma-contiguous.h>
86c8b27a 35#include <linux/efi.h>
a1e50a82 36#include <linux/swiotlb.h>
c1cc1552 37
a7f8de16 38#include <asm/boot.h>
08375198 39#include <asm/fixmap.h>
f9040773 40#include <asm/kasan.h>
a7f8de16 41#include <asm/kernel-pgtable.h>
aa03c428 42#include <asm/memory.h>
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43#include <asm/sections.h>
44#include <asm/setup.h>
45#include <asm/sizes.h>
46#include <asm/tlb.h>
e039ee4e 47#include <asm/alternative.h>
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48
49#include "mm.h"
50
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51/*
52 * We need to be able to catch inadvertent references to memstart_addr
53 * that occur (potentially in generic code) before arm64_memblock_init()
54 * executes, which assigns it its actual value. So use a default value
55 * that cannot be mistaken for a real physical address.
56 */
57phys_addr_t memstart_addr __read_mostly = ~0ULL;
a1e50a82 58phys_addr_t arm64_dma_phys_limit __read_mostly;
c1cc1552 59
ec2eaa73 60#ifdef CONFIG_BLK_DEV_INITRD
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61static int __init early_initrd(char *p)
62{
63 unsigned long start, size;
64 char *endp;
65
66 start = memparse(p, &endp);
67 if (*endp == ',') {
68 size = memparse(endp + 1, NULL);
69
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70 initrd_start = start;
71 initrd_end = start + size;
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72 }
73 return 0;
74}
75early_param("initrd", early_initrd);
ec2eaa73 76#endif
c1cc1552 77
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78/*
79 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
80 * currently assumes that for memory starting above 4G, 32-bit devices will
81 * use a DMA offset.
82 */
a7c61a34 83static phys_addr_t __init max_zone_dma_phys(void)
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84{
85 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
86 return min(offset + (1ULL << 32), memblock_end_of_DRAM());
87}
88
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89static void __init zone_sizes_init(unsigned long min, unsigned long max)
90{
91 struct memblock_region *reg;
92 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
19e7640d 93 unsigned long max_dma = min;
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94
95 memset(zone_size, 0, sizeof(zone_size));
96
c1cc1552 97 /* 4GB maximum for 32-bit only capable devices */
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98#ifdef CONFIG_ZONE_DMA
99 max_dma = PFN_DOWN(arm64_dma_phys_limit);
100 zone_size[ZONE_DMA] = max_dma - min;
101#endif
19e7640d 102 zone_size[ZONE_NORMAL] = max - max_dma;
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103
104 memcpy(zhole_size, zone_size, sizeof(zhole_size));
105
106 for_each_memblock(memory, reg) {
107 unsigned long start = memblock_region_memory_base_pfn(reg);
108 unsigned long end = memblock_region_memory_end_pfn(reg);
109
110 if (start >= max)
111 continue;
19e7640d 112
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113#ifdef CONFIG_ZONE_DMA
114 if (start < max_dma) {
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115 unsigned long dma_end = min(end, max_dma);
116 zhole_size[ZONE_DMA] -= dma_end - start;
c1cc1552 117 }
86a5906e 118#endif
19e7640d 119 if (end > max_dma) {
c1cc1552 120 unsigned long normal_end = min(end, max);
19e7640d 121 unsigned long normal_start = max(start, max_dma);
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122 zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
123 }
124 }
125
126 free_area_init_node(0, zone_size, min, zhole_size);
127}
128
129#ifdef CONFIG_HAVE_ARCH_PFN_VALID
130int pfn_valid(unsigned long pfn)
131{
68709f45 132 return memblock_is_map_memory(pfn << PAGE_SHIFT);
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133}
134EXPORT_SYMBOL(pfn_valid);
135#endif
136
137#ifndef CONFIG_SPARSEMEM
a7c61a34 138static void __init arm64_memory_present(void)
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139{
140}
141#else
a7c61a34 142static void __init arm64_memory_present(void)
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143{
144 struct memblock_region *reg;
145
146 for_each_memblock(memory, reg)
147 memory_present(0, memblock_region_memory_base_pfn(reg),
148 memblock_region_memory_end_pfn(reg));
149}
150#endif
151
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152static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
153
154/*
155 * Limit the memory size that was specified via FDT.
156 */
157static int __init early_mem(char *p)
158{
159 if (!p)
160 return 1;
161
162 memory_limit = memparse(p, &p) & PAGE_MASK;
163 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
164
165 return 0;
166}
167early_param("mem", early_mem);
168
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169void __init arm64_memblock_init(void)
170{
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171 const s64 linear_region_size = -(s64)PAGE_OFFSET;
172
173 /*
174 * Select a suitable value for the base of physical memory.
175 */
176 memstart_addr = round_down(memblock_start_of_DRAM(),
177 ARM64_MEMSTART_ALIGN);
178
179 /*
180 * Remove the memory that we will not be able to cover with the
181 * linear mapping. Take care not to clip the kernel which may be
182 * high in memory.
183 */
184 memblock_remove(max(memstart_addr + linear_region_size, __pa(_end)),
185 ULLONG_MAX);
186 if (memblock_end_of_DRAM() > linear_region_size)
187 memblock_remove(0, memblock_end_of_DRAM() - linear_region_size);
188
189 /*
190 * Apply the memory limit if it was set. Since the kernel may be loaded
191 * high up in memory, add back the kernel region that must be accessible
192 * via the linear mapping.
193 */
194 if (memory_limit != (phys_addr_t)ULLONG_MAX) {
195 memblock_enforce_memory_limit(memory_limit);
196 memblock_add(__pa(_text), (u64)(_end - _text));
197 }
6083fe74 198
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199 /*
200 * Register the kernel text, kernel data, initrd, and initial
201 * pagetables with memblock.
202 */
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203 memblock_reserve(__pa(_text), _end - _text);
204#ifdef CONFIG_BLK_DEV_INITRD
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205 if (initrd_start) {
206 memblock_reserve(initrd_start, initrd_end - initrd_start);
207
208 /* the generic initrd code expects virtual addresses */
209 initrd_start = __phys_to_virt(initrd_start);
210 initrd_end = __phys_to_virt(initrd_end);
211 }
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212#endif
213
0ceac9e0 214 early_init_fdt_scan_reserved_mem();
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215
216 /* 4GB maximum for 32-bit only capable devices */
217 if (IS_ENABLED(CONFIG_ZONE_DMA))
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218 arm64_dma_phys_limit = max_zone_dma_phys();
219 else
220 arm64_dma_phys_limit = PHYS_MASK + 1;
221 dma_contiguous_reserve(arm64_dma_phys_limit);
6ac2104d 222
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223 memblock_allow_resize();
224 memblock_dump_all();
225}
226
227void __init bootmem_init(void)
228{
229 unsigned long min, max;
230
231 min = PFN_UP(memblock_start_of_DRAM());
232 max = PFN_DOWN(memblock_end_of_DRAM());
233
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234 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
235
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236 /*
237 * Sparsemem tries to allocate bootmem in memory_present(), so must be
238 * done after the fixed reservations.
239 */
240 arm64_memory_present();
241
242 sparse_init();
243 zone_sizes_init(min, max);
244
245 high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
246 max_pfn = max_low_pfn = max;
247}
248
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249#ifndef CONFIG_SPARSEMEM_VMEMMAP
250static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
251{
252 struct page *start_pg, *end_pg;
253 unsigned long pg, pgend;
254
255 /*
256 * Convert start_pfn/end_pfn to a struct page pointer.
257 */
258 start_pg = pfn_to_page(start_pfn - 1) + 1;
259 end_pg = pfn_to_page(end_pfn - 1) + 1;
260
261 /*
262 * Convert to physical addresses, and round start upwards and end
263 * downwards.
264 */
265 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
266 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
267
268 /*
269 * If there are free pages between these, free the section of the
270 * memmap array.
271 */
272 if (pg < pgend)
273 free_bootmem(pg, pgend - pg);
274}
275
276/*
277 * The mem_map array can get very big. Free the unused area of the memory map.
278 */
279static void __init free_unused_memmap(void)
280{
281 unsigned long start, prev_end = 0;
282 struct memblock_region *reg;
283
284 for_each_memblock(memory, reg) {
285 start = __phys_to_pfn(reg->base);
286
287#ifdef CONFIG_SPARSEMEM
288 /*
289 * Take care not to free memmap entries that don't exist due
290 * to SPARSEMEM sections which aren't present.
291 */
292 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
293#endif
294 /*
295 * If we had a previous bank, and there is a space between the
296 * current bank and the previous, free it.
297 */
298 if (prev_end && prev_end < start)
299 free_memmap(prev_end, start);
300
301 /*
302 * Align up here since the VM subsystem insists that the
303 * memmap entries are valid from the bank end aligned to
304 * MAX_ORDER_NR_PAGES.
305 */
b9bcc919 306 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
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307 MAX_ORDER_NR_PAGES);
308 }
309
310#ifdef CONFIG_SPARSEMEM
311 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
312 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
313#endif
314}
315#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
316
317/*
318 * mem_init() marks the free areas in the mem_map and tells us how much memory
319 * is free. This is done after various parts of the system have claimed their
320 * memory after the kernel image.
321 */
322void __init mem_init(void)
323{
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324 swiotlb_init(1);
325
a6583c7c 326 set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
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327
328#ifndef CONFIG_SPARSEMEM_VMEMMAP
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329 free_unused_memmap();
330#endif
bee4ebd1 331 /* this will put all unused low memory onto the freelists */
0c988534 332 free_all_bootmem();
c1cc1552 333
6879ea83 334 mem_init_print_info(NULL);
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335
336#define MLK(b, t) b, t, ((t) - (b)) >> 10
337#define MLM(b, t) b, t, ((t) - (b)) >> 20
08375198 338#define MLG(b, t) b, t, ((t) - (b)) >> 30
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339#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
340
341 pr_notice("Virtual kernel memory layout:\n"
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342#ifdef CONFIG_KASAN
343 " kasan : 0x%16lx - 0x%16lx (%6ld GB)\n"
344#endif
f9040773 345 " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
08375198 346 " vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
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347 " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
348 " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
349 " .data : 0x%p" " - 0x%p" " (%6ld KB)\n"
c1cc1552 350#ifdef CONFIG_SPARSEMEM_VMEMMAP
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351 " vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
352 " 0x%16lx - 0x%16lx (%6ld MB actual)\n"
c1cc1552 353#endif
08375198 354 " fixed : 0x%16lx - 0x%16lx (%6ld KB)\n"
aa03c428 355 " PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n"
f9040773 356 " memory : 0x%16lx - 0x%16lx (%6ld MB)\n",
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357#ifdef CONFIG_KASAN
358 MLG(KASAN_SHADOW_START, KASAN_SHADOW_END),
359#endif
f9040773 360 MLM(MODULES_VADDR, MODULES_END),
08375198 361 MLG(VMALLOC_START, VMALLOC_END),
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362 MLK_ROUNDUP(__init_begin, __init_end),
363 MLK_ROUNDUP(_text, _etext),
364 MLK_ROUNDUP(_sdata, _edata),
c1cc1552 365#ifdef CONFIG_SPARSEMEM_VMEMMAP
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366 MLG((unsigned long)vmemmap,
367 (unsigned long)vmemmap + VMEMMAP_SIZE),
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368 MLM((unsigned long)virt_to_page(PAGE_OFFSET),
369 (unsigned long)virt_to_page(high_memory)),
370#endif
08375198 371 MLK(FIXADDR_START, FIXADDR_TOP),
aa03c428 372 MLM(PCI_IO_START, PCI_IO_END),
f9040773 373 MLM(PAGE_OFFSET, (unsigned long)high_memory));
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374
375#undef MLK
376#undef MLM
377#undef MLK_ROUNDUP
378
379 /*
380 * Check boundaries twice: Some fundamental inconsistencies can be
381 * detected at build time already.
382 */
383#ifdef CONFIG_COMPAT
384 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
385#endif
386 BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
387 BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
388
bee4ebd1 389 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
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390 extern int sysctl_overcommit_memory;
391 /*
392 * On a machine this small we won't get anywhere without
393 * overcommit, so turn it on by default.
394 */
395 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
396 }
397}
398
399void free_initmem(void)
400{
9af5b807 401 free_initmem_default(0);
f9040773 402 fixup_init();
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403}
404
405#ifdef CONFIG_BLK_DEV_INITRD
406
662ba3db 407static int keep_initrd __initdata;
c1cc1552 408
662ba3db 409void __init free_initrd_mem(unsigned long start, unsigned long end)
c1cc1552 410{
0145058c 411 if (!keep_initrd)
9af5b807 412 free_reserved_area((void *)start, (void *)end, 0, "initrd");
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413}
414
415static int __init keepinitrd_setup(char *__unused)
416{
417 keep_initrd = 1;
418 return 1;
419}
420
421__setup("keepinitrd", keepinitrd_setup);
422#endif
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423
424/*
425 * Dump out memory limit information on panic.
426 */
427static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
428{
429 if (memory_limit != (phys_addr_t)ULLONG_MAX) {
430 pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
431 } else {
432 pr_emerg("Memory Limit: none\n");
433 }
434 return 0;
435}
436
437static struct notifier_block mem_limit_notifier = {
438 .notifier_call = dump_mem_limit,
439};
440
441static int __init register_mem_limit_dumper(void)
442{
443 atomic_notifier_chain_register(&panic_notifier_list,
444 &mem_limit_notifier);
445 return 0;
446}
447__initcall(register_mem_limit_dumper);