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[linux/fpc-iii.git] / arch / arm / mm / init.c
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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/mm/init.c
5 * Copyright (C) 1995-2005 Russell King
6 */
7 #include <linux/kernel.h>
8 #include <linux/errno.h>
9 #include <linux/swap.h>
10 #include <linux/init.h>
11 #include <linux/mman.h>
12 #include <linux/sched/signal.h>
13 #include <linux/sched/task.h>
14 #include <linux/export.h>
15 #include <linux/nodemask.h>
16 #include <linux/initrd.h>
17 #include <linux/of_fdt.h>
18 #include <linux/highmem.h>
19 #include <linux/gfp.h>
20 #include <linux/memblock.h>
21 #include <linux/dma-contiguous.h>
22 #include <linux/sizes.h>
23 #include <linux/stop_machine.h>
24 #include <linux/swiotlb.h>
26 #include <asm/cp15.h>
27 #include <asm/mach-types.h>
28 #include <asm/memblock.h>
29 #include <asm/memory.h>
30 #include <asm/prom.h>
31 #include <asm/sections.h>
32 #include <asm/setup.h>
33 #include <asm/set_memory.h>
34 #include <asm/system_info.h>
35 #include <asm/tlb.h>
36 #include <asm/fixmap.h>
37 #include <asm/ptdump.h>
39 #include <asm/mach/arch.h>
40 #include <asm/mach/map.h>
42 #include "mm.h"
44 #ifdef CONFIG_CPU_CP15_MMU
45 unsigned long __init __clear_cr(unsigned long mask)
47 cr_alignment = cr_alignment & ~mask;
48 return cr_alignment;
50 #endif
52 #ifdef CONFIG_BLK_DEV_INITRD
53 static int __init parse_tag_initrd(const struct tag *tag)
55 pr_warn("ATAG_INITRD is deprecated; "
56 "please update your bootloader.\n");
57 phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
58 phys_initrd_size = tag->u.initrd.size;
59 return 0;
62 __tagtable(ATAG_INITRD, parse_tag_initrd);
64 static int __init parse_tag_initrd2(const struct tag *tag)
66 phys_initrd_start = tag->u.initrd.start;
67 phys_initrd_size = tag->u.initrd.size;
68 return 0;
71 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
72 #endif
74 static void __init find_limits(unsigned long *min, unsigned long *max_low,
75 unsigned long *max_high)
77 *max_low = PFN_DOWN(memblock_get_current_limit());
78 *min = PFN_UP(memblock_start_of_DRAM());
79 *max_high = PFN_DOWN(memblock_end_of_DRAM());
82 #ifdef CONFIG_ZONE_DMA
84 phys_addr_t arm_dma_zone_size __read_mostly;
85 EXPORT_SYMBOL(arm_dma_zone_size);
88 * The DMA mask corresponding to the maximum bus address allocatable
89 * using GFP_DMA. The default here places no restriction on DMA
90 * allocations. This must be the smallest DMA mask in the system,
91 * so a successful GFP_DMA allocation will always satisfy this.
93 phys_addr_t arm_dma_limit;
94 unsigned long arm_dma_pfn_limit;
96 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
97 unsigned long dma_size)
99 if (size[0] <= dma_size)
100 return;
102 size[ZONE_NORMAL] = size[0] - dma_size;
103 size[ZONE_DMA] = dma_size;
104 hole[ZONE_NORMAL] = hole[0];
105 hole[ZONE_DMA] = 0;
107 #endif
109 void __init setup_dma_zone(const struct machine_desc *mdesc)
111 #ifdef CONFIG_ZONE_DMA
112 if (mdesc->dma_zone_size) {
113 arm_dma_zone_size = mdesc->dma_zone_size;
114 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
115 } else
116 arm_dma_limit = 0xffffffff;
117 arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
118 #endif
121 static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
122 unsigned long max_high)
124 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
125 struct memblock_region *reg;
128 * initialise the zones.
130 memset(zone_size, 0, sizeof(zone_size));
133 * The memory size has already been determined. If we need
134 * to do anything fancy with the allocation of this memory
135 * to the zones, now is the time to do it.
137 zone_size[0] = max_low - min;
138 #ifdef CONFIG_HIGHMEM
139 zone_size[ZONE_HIGHMEM] = max_high - max_low;
140 #endif
143 * Calculate the size of the holes.
144 * holes = node_size - sum(bank_sizes)
146 memcpy(zhole_size, zone_size, sizeof(zhole_size));
147 for_each_memblock(memory, reg) {
148 unsigned long start = memblock_region_memory_base_pfn(reg);
149 unsigned long end = memblock_region_memory_end_pfn(reg);
151 if (start < max_low) {
152 unsigned long low_end = min(end, max_low);
153 zhole_size[0] -= low_end - start;
155 #ifdef CONFIG_HIGHMEM
156 if (end > max_low) {
157 unsigned long high_start = max(start, max_low);
158 zhole_size[ZONE_HIGHMEM] -= end - high_start;
160 #endif
163 #ifdef CONFIG_ZONE_DMA
165 * Adjust the sizes according to any special requirements for
166 * this machine type.
168 if (arm_dma_zone_size)
169 arm_adjust_dma_zone(zone_size, zhole_size,
170 arm_dma_zone_size >> PAGE_SHIFT);
171 #endif
173 free_area_init_node(0, zone_size, min, zhole_size);
176 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
177 int pfn_valid(unsigned long pfn)
179 phys_addr_t addr = __pfn_to_phys(pfn);
181 if (__phys_to_pfn(addr) != pfn)
182 return 0;
184 return memblock_is_map_memory(addr);
186 EXPORT_SYMBOL(pfn_valid);
187 #endif
189 static bool arm_memblock_steal_permitted = true;
191 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
193 phys_addr_t phys;
195 BUG_ON(!arm_memblock_steal_permitted);
197 phys = memblock_phys_alloc(size, align);
198 if (!phys)
199 panic("Failed to steal %pa bytes at %pS\n",
200 &size, (void *)_RET_IP_);
202 memblock_free(phys, size);
203 memblock_remove(phys, size);
205 return phys;
208 static void __init arm_initrd_init(void)
210 #ifdef CONFIG_BLK_DEV_INITRD
211 phys_addr_t start;
212 unsigned long size;
214 initrd_start = initrd_end = 0;
216 if (!phys_initrd_size)
217 return;
220 * Round the memory region to page boundaries as per free_initrd_mem()
221 * This allows us to detect whether the pages overlapping the initrd
222 * are in use, but more importantly, reserves the entire set of pages
223 * as we don't want these pages allocated for other purposes.
225 start = round_down(phys_initrd_start, PAGE_SIZE);
226 size = phys_initrd_size + (phys_initrd_start - start);
227 size = round_up(size, PAGE_SIZE);
229 if (!memblock_is_region_memory(start, size)) {
230 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
231 (u64)start, size);
232 return;
235 if (memblock_is_region_reserved(start, size)) {
236 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
237 (u64)start, size);
238 return;
241 memblock_reserve(start, size);
243 /* Now convert initrd to virtual addresses */
244 initrd_start = __phys_to_virt(phys_initrd_start);
245 initrd_end = initrd_start + phys_initrd_size;
246 #endif
249 #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
250 void check_cpu_icache_size(int cpuid)
252 u32 size, ctr;
254 asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
256 size = 1 << ((ctr & 0xf) + 2);
257 if (cpuid != 0 && icache_size != size)
258 pr_info("CPU%u: detected I-Cache line size mismatch, workaround enabled\n",
259 cpuid);
260 if (icache_size > size)
261 icache_size = size;
263 #endif
265 void __init arm_memblock_init(const struct machine_desc *mdesc)
267 /* Register the kernel text, kernel data and initrd with memblock. */
268 memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
270 arm_initrd_init();
272 arm_mm_memblock_reserve();
274 /* reserve any platform specific memblock areas */
275 if (mdesc->reserve)
276 mdesc->reserve();
278 early_init_fdt_reserve_self();
279 early_init_fdt_scan_reserved_mem();
281 /* reserve memory for DMA contiguous allocations */
282 dma_contiguous_reserve(arm_dma_limit);
284 arm_memblock_steal_permitted = false;
285 memblock_dump_all();
288 void __init bootmem_init(void)
290 memblock_allow_resize();
292 find_limits(&min_low_pfn, &max_low_pfn, &max_pfn);
294 early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
295 (phys_addr_t)max_low_pfn << PAGE_SHIFT);
298 * Sparsemem tries to allocate bootmem in memory_present(),
299 * so must be done after the fixed reservations
301 memblocks_present();
304 * sparse_init() needs the bootmem allocator up and running.
306 sparse_init();
309 * Now free the memory - free_area_init_node needs
310 * the sparse mem_map arrays initialized by sparse_init()
311 * for memmap_init_zone(), otherwise all PFNs are invalid.
313 zone_sizes_init(min_low_pfn, max_low_pfn, max_pfn);
317 * Poison init memory with an undefined instruction (ARM) or a branch to an
318 * undefined instruction (Thumb).
320 static inline void poison_init_mem(void *s, size_t count)
322 u32 *p = (u32 *)s;
323 for (; count != 0; count -= 4)
324 *p++ = 0xe7fddef0;
327 static inline void __init
328 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
330 struct page *start_pg, *end_pg;
331 phys_addr_t pg, pgend;
334 * Convert start_pfn/end_pfn to a struct page pointer.
336 start_pg = pfn_to_page(start_pfn - 1) + 1;
337 end_pg = pfn_to_page(end_pfn - 1) + 1;
340 * Convert to physical addresses, and
341 * round start upwards and end downwards.
343 pg = PAGE_ALIGN(__pa(start_pg));
344 pgend = __pa(end_pg) & PAGE_MASK;
347 * If there are free pages between these,
348 * free the section of the memmap array.
350 if (pg < pgend)
351 memblock_free_early(pg, pgend - pg);
355 * The mem_map array can get very big. Free the unused area of the memory map.
357 static void __init free_unused_memmap(void)
359 unsigned long start, prev_end = 0;
360 struct memblock_region *reg;
363 * This relies on each bank being in address order.
364 * The banks are sorted previously in bootmem_init().
366 for_each_memblock(memory, reg) {
367 start = memblock_region_memory_base_pfn(reg);
369 #ifdef CONFIG_SPARSEMEM
371 * Take care not to free memmap entries that don't exist
372 * due to SPARSEMEM sections which aren't present.
374 start = min(start,
375 ALIGN(prev_end, PAGES_PER_SECTION));
376 #else
378 * Align down here since the VM subsystem insists that the
379 * memmap entries are valid from the bank start aligned to
380 * MAX_ORDER_NR_PAGES.
382 start = round_down(start, MAX_ORDER_NR_PAGES);
383 #endif
385 * If we had a previous bank, and there is a space
386 * between the current bank and the previous, free it.
388 if (prev_end && prev_end < start)
389 free_memmap(prev_end, start);
392 * Align up here since the VM subsystem insists that the
393 * memmap entries are valid from the bank end aligned to
394 * MAX_ORDER_NR_PAGES.
396 prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
397 MAX_ORDER_NR_PAGES);
400 #ifdef CONFIG_SPARSEMEM
401 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
402 free_memmap(prev_end,
403 ALIGN(prev_end, PAGES_PER_SECTION));
404 #endif
407 #ifdef CONFIG_HIGHMEM
408 static inline void free_area_high(unsigned long pfn, unsigned long end)
410 for (; pfn < end; pfn++)
411 free_highmem_page(pfn_to_page(pfn));
413 #endif
415 static void __init free_highpages(void)
417 #ifdef CONFIG_HIGHMEM
418 unsigned long max_low = max_low_pfn;
419 struct memblock_region *mem, *res;
421 /* set highmem page free */
422 for_each_memblock(memory, mem) {
423 unsigned long start = memblock_region_memory_base_pfn(mem);
424 unsigned long end = memblock_region_memory_end_pfn(mem);
426 /* Ignore complete lowmem entries */
427 if (end <= max_low)
428 continue;
430 if (memblock_is_nomap(mem))
431 continue;
433 /* Truncate partial highmem entries */
434 if (start < max_low)
435 start = max_low;
437 /* Find and exclude any reserved regions */
438 for_each_memblock(reserved, res) {
439 unsigned long res_start, res_end;
441 res_start = memblock_region_reserved_base_pfn(res);
442 res_end = memblock_region_reserved_end_pfn(res);
444 if (res_end < start)
445 continue;
446 if (res_start < start)
447 res_start = start;
448 if (res_start > end)
449 res_start = end;
450 if (res_end > end)
451 res_end = end;
452 if (res_start != start)
453 free_area_high(start, res_start);
454 start = res_end;
455 if (start == end)
456 break;
459 /* And now free anything which remains */
460 if (start < end)
461 free_area_high(start, end);
463 #endif
467 * mem_init() marks the free areas in the mem_map and tells us how much
468 * memory is free. This is done after various parts of the system have
469 * claimed their memory after the kernel image.
471 void __init mem_init(void)
473 #ifdef CONFIG_ARM_LPAE
474 swiotlb_init(1);
475 #endif
477 set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
479 /* this will put all unused low memory onto the freelists */
480 free_unused_memmap();
481 memblock_free_all();
483 #ifdef CONFIG_SA1111
484 /* now that our DMA memory is actually so designated, we can free it */
485 free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
486 #endif
488 free_highpages();
490 mem_init_print_info(NULL);
493 * Check boundaries twice: Some fundamental inconsistencies can
494 * be detected at build time already.
496 #ifdef CONFIG_MMU
497 BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
498 BUG_ON(TASK_SIZE > MODULES_VADDR);
499 #endif
501 #ifdef CONFIG_HIGHMEM
502 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
503 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
504 #endif
507 #ifdef CONFIG_STRICT_KERNEL_RWX
508 struct section_perm {
509 const char *name;
510 unsigned long start;
511 unsigned long end;
512 pmdval_t mask;
513 pmdval_t prot;
514 pmdval_t clear;
517 /* First section-aligned location at or after __start_rodata. */
518 extern char __start_rodata_section_aligned[];
520 static struct section_perm nx_perms[] = {
521 /* Make pages tables, etc before _stext RW (set NX). */
523 .name = "pre-text NX",
524 .start = PAGE_OFFSET,
525 .end = (unsigned long)_stext,
526 .mask = ~PMD_SECT_XN,
527 .prot = PMD_SECT_XN,
529 /* Make init RW (set NX). */
531 .name = "init NX",
532 .start = (unsigned long)__init_begin,
533 .end = (unsigned long)_sdata,
534 .mask = ~PMD_SECT_XN,
535 .prot = PMD_SECT_XN,
537 /* Make rodata NX (set RO in ro_perms below). */
539 .name = "rodata NX",
540 .start = (unsigned long)__start_rodata_section_aligned,
541 .end = (unsigned long)__init_begin,
542 .mask = ~PMD_SECT_XN,
543 .prot = PMD_SECT_XN,
547 static struct section_perm ro_perms[] = {
548 /* Make kernel code and rodata RX (set RO). */
550 .name = "text/rodata RO",
551 .start = (unsigned long)_stext,
552 .end = (unsigned long)__init_begin,
553 #ifdef CONFIG_ARM_LPAE
554 .mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
555 .prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
556 #else
557 .mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
558 .prot = PMD_SECT_APX | PMD_SECT_AP_WRITE,
559 .clear = PMD_SECT_AP_WRITE,
560 #endif
565 * Updates section permissions only for the current mm (sections are
566 * copied into each mm). During startup, this is the init_mm. Is only
567 * safe to be called with preemption disabled, as under stop_machine().
569 static inline void section_update(unsigned long addr, pmdval_t mask,
570 pmdval_t prot, struct mm_struct *mm)
572 pmd_t *pmd;
574 pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
576 #ifdef CONFIG_ARM_LPAE
577 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
578 #else
579 if (addr & SECTION_SIZE)
580 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
581 else
582 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
583 #endif
584 flush_pmd_entry(pmd);
585 local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
588 /* Make sure extended page tables are in use. */
589 static inline bool arch_has_strict_perms(void)
591 if (cpu_architecture() < CPU_ARCH_ARMv6)
592 return false;
594 return !!(get_cr() & CR_XP);
597 static void set_section_perms(struct section_perm *perms, int n, bool set,
598 struct mm_struct *mm)
600 size_t i;
601 unsigned long addr;
603 if (!arch_has_strict_perms())
604 return;
606 for (i = 0; i < n; i++) {
607 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
608 !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
609 pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
610 perms[i].name, perms[i].start, perms[i].end,
611 SECTION_SIZE);
612 continue;
615 for (addr = perms[i].start;
616 addr < perms[i].end;
617 addr += SECTION_SIZE)
618 section_update(addr, perms[i].mask,
619 set ? perms[i].prot : perms[i].clear, mm);
625 * update_sections_early intended to be called only through stop_machine
626 * framework and executed by only one CPU while all other CPUs will spin and
627 * wait, so no locking is required in this function.
629 static void update_sections_early(struct section_perm perms[], int n)
631 struct task_struct *t, *s;
633 for_each_process(t) {
634 if (t->flags & PF_KTHREAD)
635 continue;
636 for_each_thread(t, s)
637 if (s->mm)
638 set_section_perms(perms, n, true, s->mm);
640 set_section_perms(perms, n, true, current->active_mm);
641 set_section_perms(perms, n, true, &init_mm);
644 static int __fix_kernmem_perms(void *unused)
646 update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
647 return 0;
650 static void fix_kernmem_perms(void)
652 stop_machine(__fix_kernmem_perms, NULL, NULL);
655 static int __mark_rodata_ro(void *unused)
657 update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
658 return 0;
661 static int kernel_set_to_readonly __read_mostly;
663 void mark_rodata_ro(void)
665 kernel_set_to_readonly = 1;
666 stop_machine(__mark_rodata_ro, NULL, NULL);
667 debug_checkwx();
670 void set_kernel_text_rw(void)
672 if (!kernel_set_to_readonly)
673 return;
675 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
676 current->active_mm);
679 void set_kernel_text_ro(void)
681 if (!kernel_set_to_readonly)
682 return;
684 set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
685 current->active_mm);
688 #else
689 static inline void fix_kernmem_perms(void) { }
690 #endif /* CONFIG_STRICT_KERNEL_RWX */
692 void free_initmem(void)
694 fix_kernmem_perms();
696 poison_init_mem(__init_begin, __init_end - __init_begin);
697 if (!machine_is_integrator() && !machine_is_cintegrator())
698 free_initmem_default(-1);
701 #ifdef CONFIG_BLK_DEV_INITRD
702 void free_initrd_mem(unsigned long start, unsigned long end)
704 if (start == initrd_start)
705 start = round_down(start, PAGE_SIZE);
706 if (end == initrd_end)
707 end = round_up(end, PAGE_SIZE);
709 poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
710 free_reserved_area((void *)start, (void *)end, -1, "initrd");
712 #endif