xref: /openbmc/linux/arch/arm/mm/init.c (revision a09975bf)
1 /*
2  *  linux/arch/arm/mm/init.c
3  *
4  *  Copyright (C) 1995-2005 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/swap.h>
13 #include <linux/init.h>
14 #include <linux/bootmem.h>
15 #include <linux/mman.h>
16 #include <linux/export.h>
17 #include <linux/nodemask.h>
18 #include <linux/initrd.h>
19 #include <linux/of_fdt.h>
20 #include <linux/highmem.h>
21 #include <linux/gfp.h>
22 #include <linux/memblock.h>
23 #include <linux/dma-contiguous.h>
24 #include <linux/sizes.h>
25 #include <linux/stop_machine.h>
26 
27 #include <asm/cp15.h>
28 #include <asm/mach-types.h>
29 #include <asm/memblock.h>
30 #include <asm/prom.h>
31 #include <asm/sections.h>
32 #include <asm/setup.h>
33 #include <asm/system_info.h>
34 #include <asm/tlb.h>
35 #include <asm/fixmap.h>
36 
37 #include <asm/mach/arch.h>
38 #include <asm/mach/map.h>
39 
40 #include "mm.h"
41 
42 #ifdef CONFIG_CPU_CP15_MMU
43 unsigned long __init __clear_cr(unsigned long mask)
44 {
45 	cr_alignment = cr_alignment & ~mask;
46 	return cr_alignment;
47 }
48 #endif
49 
50 static phys_addr_t phys_initrd_start __initdata = 0;
51 static unsigned long phys_initrd_size __initdata = 0;
52 
53 static int __init early_initrd(char *p)
54 {
55 	phys_addr_t start;
56 	unsigned long size;
57 	char *endp;
58 
59 	start = memparse(p, &endp);
60 	if (*endp == ',') {
61 		size = memparse(endp + 1, NULL);
62 
63 		phys_initrd_start = start;
64 		phys_initrd_size = size;
65 	}
66 	return 0;
67 }
68 early_param("initrd", early_initrd);
69 
70 static int __init parse_tag_initrd(const struct tag *tag)
71 {
72 	pr_warn("ATAG_INITRD is deprecated; "
73 		"please update your bootloader.\n");
74 	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
75 	phys_initrd_size = tag->u.initrd.size;
76 	return 0;
77 }
78 
79 __tagtable(ATAG_INITRD, parse_tag_initrd);
80 
81 static int __init parse_tag_initrd2(const struct tag *tag)
82 {
83 	phys_initrd_start = tag->u.initrd.start;
84 	phys_initrd_size = tag->u.initrd.size;
85 	return 0;
86 }
87 
88 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
89 
90 static void __init find_limits(unsigned long *min, unsigned long *max_low,
91 			       unsigned long *max_high)
92 {
93 	*max_low = PFN_DOWN(memblock_get_current_limit());
94 	*min = PFN_UP(memblock_start_of_DRAM());
95 	*max_high = PFN_DOWN(memblock_end_of_DRAM());
96 }
97 
98 #ifdef CONFIG_ZONE_DMA
99 
100 phys_addr_t arm_dma_zone_size __read_mostly;
101 EXPORT_SYMBOL(arm_dma_zone_size);
102 
103 /*
104  * The DMA mask corresponding to the maximum bus address allocatable
105  * using GFP_DMA.  The default here places no restriction on DMA
106  * allocations.  This must be the smallest DMA mask in the system,
107  * so a successful GFP_DMA allocation will always satisfy this.
108  */
109 phys_addr_t arm_dma_limit;
110 unsigned long arm_dma_pfn_limit;
111 
112 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
113 	unsigned long dma_size)
114 {
115 	if (size[0] <= dma_size)
116 		return;
117 
118 	size[ZONE_NORMAL] = size[0] - dma_size;
119 	size[ZONE_DMA] = dma_size;
120 	hole[ZONE_NORMAL] = hole[0];
121 	hole[ZONE_DMA] = 0;
122 }
123 #endif
124 
125 void __init setup_dma_zone(const struct machine_desc *mdesc)
126 {
127 #ifdef CONFIG_ZONE_DMA
128 	if (mdesc->dma_zone_size) {
129 		arm_dma_zone_size = mdesc->dma_zone_size;
130 		arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
131 	} else
132 		arm_dma_limit = 0xffffffff;
133 	arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
134 #endif
135 }
136 
137 static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
138 	unsigned long max_high)
139 {
140 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
141 	struct memblock_region *reg;
142 
143 	/*
144 	 * initialise the zones.
145 	 */
146 	memset(zone_size, 0, sizeof(zone_size));
147 
148 	/*
149 	 * The memory size has already been determined.  If we need
150 	 * to do anything fancy with the allocation of this memory
151 	 * to the zones, now is the time to do it.
152 	 */
153 	zone_size[0] = max_low - min;
154 #ifdef CONFIG_HIGHMEM
155 	zone_size[ZONE_HIGHMEM] = max_high - max_low;
156 #endif
157 
158 	/*
159 	 * Calculate the size of the holes.
160 	 *  holes = node_size - sum(bank_sizes)
161 	 */
162 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
163 	for_each_memblock(memory, reg) {
164 		unsigned long start = memblock_region_memory_base_pfn(reg);
165 		unsigned long end = memblock_region_memory_end_pfn(reg);
166 
167 		if (start < max_low) {
168 			unsigned long low_end = min(end, max_low);
169 			zhole_size[0] -= low_end - start;
170 		}
171 #ifdef CONFIG_HIGHMEM
172 		if (end > max_low) {
173 			unsigned long high_start = max(start, max_low);
174 			zhole_size[ZONE_HIGHMEM] -= end - high_start;
175 		}
176 #endif
177 	}
178 
179 #ifdef CONFIG_ZONE_DMA
180 	/*
181 	 * Adjust the sizes according to any special requirements for
182 	 * this machine type.
183 	 */
184 	if (arm_dma_zone_size)
185 		arm_adjust_dma_zone(zone_size, zhole_size,
186 			arm_dma_zone_size >> PAGE_SHIFT);
187 #endif
188 
189 	free_area_init_node(0, zone_size, min, zhole_size);
190 }
191 
192 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
193 int pfn_valid(unsigned long pfn)
194 {
195 	return memblock_is_map_memory(__pfn_to_phys(pfn));
196 }
197 EXPORT_SYMBOL(pfn_valid);
198 #endif
199 
200 #ifndef CONFIG_SPARSEMEM
201 static void __init arm_memory_present(void)
202 {
203 }
204 #else
205 static void __init arm_memory_present(void)
206 {
207 	struct memblock_region *reg;
208 
209 	for_each_memblock(memory, reg)
210 		memory_present(0, memblock_region_memory_base_pfn(reg),
211 			       memblock_region_memory_end_pfn(reg));
212 }
213 #endif
214 
215 static bool arm_memblock_steal_permitted = true;
216 
217 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
218 {
219 	phys_addr_t phys;
220 
221 	BUG_ON(!arm_memblock_steal_permitted);
222 
223 	phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
224 	memblock_free(phys, size);
225 	memblock_remove(phys, size);
226 
227 	return phys;
228 }
229 
230 void __init arm_memblock_init(const struct machine_desc *mdesc)
231 {
232 	/* Register the kernel text, kernel data and initrd with memblock. */
233 	memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
234 
235 #ifdef CONFIG_BLK_DEV_INITRD
236 	/* FDT scan will populate initrd_start */
237 	if (initrd_start && !phys_initrd_size) {
238 		phys_initrd_start = __virt_to_phys(initrd_start);
239 		phys_initrd_size = initrd_end - initrd_start;
240 	}
241 	initrd_start = initrd_end = 0;
242 	if (phys_initrd_size &&
243 	    !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
244 		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
245 		       (u64)phys_initrd_start, phys_initrd_size);
246 		phys_initrd_start = phys_initrd_size = 0;
247 	}
248 	if (phys_initrd_size &&
249 	    memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
250 		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
251 		       (u64)phys_initrd_start, phys_initrd_size);
252 		phys_initrd_start = phys_initrd_size = 0;
253 	}
254 	if (phys_initrd_size) {
255 		memblock_reserve(phys_initrd_start, phys_initrd_size);
256 
257 		/* Now convert initrd to virtual addresses */
258 		initrd_start = __phys_to_virt(phys_initrd_start);
259 		initrd_end = initrd_start + phys_initrd_size;
260 	}
261 #endif
262 
263 	arm_mm_memblock_reserve();
264 
265 	/* reserve any platform specific memblock areas */
266 	if (mdesc->reserve)
267 		mdesc->reserve();
268 
269 	early_init_fdt_reserve_self();
270 	early_init_fdt_scan_reserved_mem();
271 
272 	/* reserve memory for DMA contiguous allocations */
273 	dma_contiguous_reserve(arm_dma_limit);
274 
275 	arm_memblock_steal_permitted = false;
276 	memblock_dump_all();
277 }
278 
279 void __init bootmem_init(void)
280 {
281 	unsigned long min, max_low, max_high;
282 
283 	memblock_allow_resize();
284 	max_low = max_high = 0;
285 
286 	find_limits(&min, &max_low, &max_high);
287 
288 	early_memtest((phys_addr_t)min << PAGE_SHIFT,
289 		      (phys_addr_t)max_low << PAGE_SHIFT);
290 
291 	/*
292 	 * Sparsemem tries to allocate bootmem in memory_present(),
293 	 * so must be done after the fixed reservations
294 	 */
295 	arm_memory_present();
296 
297 	/*
298 	 * sparse_init() needs the bootmem allocator up and running.
299 	 */
300 	sparse_init();
301 
302 	/*
303 	 * Now free the memory - free_area_init_node needs
304 	 * the sparse mem_map arrays initialized by sparse_init()
305 	 * for memmap_init_zone(), otherwise all PFNs are invalid.
306 	 */
307 	zone_sizes_init(min, max_low, max_high);
308 
309 	/*
310 	 * This doesn't seem to be used by the Linux memory manager any
311 	 * more, but is used by ll_rw_block.  If we can get rid of it, we
312 	 * also get rid of some of the stuff above as well.
313 	 */
314 	min_low_pfn = min;
315 	max_low_pfn = max_low;
316 	max_pfn = max_high;
317 }
318 
319 /*
320  * Poison init memory with an undefined instruction (ARM) or a branch to an
321  * undefined instruction (Thumb).
322  */
323 static inline void poison_init_mem(void *s, size_t count)
324 {
325 	u32 *p = (u32 *)s;
326 	for (; count != 0; count -= 4)
327 		*p++ = 0xe7fddef0;
328 }
329 
330 static inline void
331 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
332 {
333 	struct page *start_pg, *end_pg;
334 	phys_addr_t pg, pgend;
335 
336 	/*
337 	 * Convert start_pfn/end_pfn to a struct page pointer.
338 	 */
339 	start_pg = pfn_to_page(start_pfn - 1) + 1;
340 	end_pg = pfn_to_page(end_pfn - 1) + 1;
341 
342 	/*
343 	 * Convert to physical addresses, and
344 	 * round start upwards and end downwards.
345 	 */
346 	pg = PAGE_ALIGN(__pa(start_pg));
347 	pgend = __pa(end_pg) & PAGE_MASK;
348 
349 	/*
350 	 * If there are free pages between these,
351 	 * free the section of the memmap array.
352 	 */
353 	if (pg < pgend)
354 		memblock_free_early(pg, pgend - pg);
355 }
356 
357 /*
358  * The mem_map array can get very big.  Free the unused area of the memory map.
359  */
360 static void __init free_unused_memmap(void)
361 {
362 	unsigned long start, prev_end = 0;
363 	struct memblock_region *reg;
364 
365 	/*
366 	 * This relies on each bank being in address order.
367 	 * The banks are sorted previously in bootmem_init().
368 	 */
369 	for_each_memblock(memory, reg) {
370 		start = memblock_region_memory_base_pfn(reg);
371 
372 #ifdef CONFIG_SPARSEMEM
373 		/*
374 		 * Take care not to free memmap entries that don't exist
375 		 * due to SPARSEMEM sections which aren't present.
376 		 */
377 		start = min(start,
378 				 ALIGN(prev_end, PAGES_PER_SECTION));
379 #else
380 		/*
381 		 * Align down here since the VM subsystem insists that the
382 		 * memmap entries are valid from the bank start aligned to
383 		 * MAX_ORDER_NR_PAGES.
384 		 */
385 		start = round_down(start, MAX_ORDER_NR_PAGES);
386 #endif
387 		/*
388 		 * If we had a previous bank, and there is a space
389 		 * between the current bank and the previous, free it.
390 		 */
391 		if (prev_end && prev_end < start)
392 			free_memmap(prev_end, start);
393 
394 		/*
395 		 * Align up here since the VM subsystem insists that the
396 		 * memmap entries are valid from the bank end aligned to
397 		 * MAX_ORDER_NR_PAGES.
398 		 */
399 		prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
400 				 MAX_ORDER_NR_PAGES);
401 	}
402 
403 #ifdef CONFIG_SPARSEMEM
404 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
405 		free_memmap(prev_end,
406 			    ALIGN(prev_end, PAGES_PER_SECTION));
407 #endif
408 }
409 
410 #ifdef CONFIG_HIGHMEM
411 static inline void free_area_high(unsigned long pfn, unsigned long end)
412 {
413 	for (; pfn < end; pfn++)
414 		free_highmem_page(pfn_to_page(pfn));
415 }
416 #endif
417 
418 static void __init free_highpages(void)
419 {
420 #ifdef CONFIG_HIGHMEM
421 	unsigned long max_low = max_low_pfn;
422 	struct memblock_region *mem, *res;
423 
424 	/* set highmem page free */
425 	for_each_memblock(memory, mem) {
426 		unsigned long start = memblock_region_memory_base_pfn(mem);
427 		unsigned long end = memblock_region_memory_end_pfn(mem);
428 
429 		/* Ignore complete lowmem entries */
430 		if (end <= max_low)
431 			continue;
432 
433 		if (memblock_is_nomap(mem))
434 			continue;
435 
436 		/* Truncate partial highmem entries */
437 		if (start < max_low)
438 			start = max_low;
439 
440 		/* Find and exclude any reserved regions */
441 		for_each_memblock(reserved, res) {
442 			unsigned long res_start, res_end;
443 
444 			res_start = memblock_region_reserved_base_pfn(res);
445 			res_end = memblock_region_reserved_end_pfn(res);
446 
447 			if (res_end < start)
448 				continue;
449 			if (res_start < start)
450 				res_start = start;
451 			if (res_start > end)
452 				res_start = end;
453 			if (res_end > end)
454 				res_end = end;
455 			if (res_start != start)
456 				free_area_high(start, res_start);
457 			start = res_end;
458 			if (start == end)
459 				break;
460 		}
461 
462 		/* And now free anything which remains */
463 		if (start < end)
464 			free_area_high(start, end);
465 	}
466 #endif
467 }
468 
469 /*
470  * mem_init() marks the free areas in the mem_map and tells us how much
471  * memory is free.  This is done after various parts of the system have
472  * claimed their memory after the kernel image.
473  */
474 void __init mem_init(void)
475 {
476 #ifdef CONFIG_HAVE_TCM
477 	/* These pointers are filled in on TCM detection */
478 	extern u32 dtcm_end;
479 	extern u32 itcm_end;
480 #endif
481 
482 	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
483 
484 	/* this will put all unused low memory onto the freelists */
485 	free_unused_memmap();
486 	free_all_bootmem();
487 
488 #ifdef CONFIG_SA1111
489 	/* now that our DMA memory is actually so designated, we can free it */
490 	free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
491 #endif
492 
493 	free_highpages();
494 
495 	mem_init_print_info(NULL);
496 
497 #define MLK(b, t) b, t, ((t) - (b)) >> 10
498 #define MLM(b, t) b, t, ((t) - (b)) >> 20
499 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
500 
501 	pr_notice("Virtual kernel memory layout:\n"
502 			"    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
503 #ifdef CONFIG_HAVE_TCM
504 			"    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
505 			"    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
506 #endif
507 			"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
508 			"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
509 			"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
510 #ifdef CONFIG_HIGHMEM
511 			"    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
512 #endif
513 #ifdef CONFIG_MODULES
514 			"    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
515 #endif
516 			"      .text : 0x%p" " - 0x%p" "   (%4td kB)\n"
517 			"      .init : 0x%p" " - 0x%p" "   (%4td kB)\n"
518 			"      .data : 0x%p" " - 0x%p" "   (%4td kB)\n"
519 			"       .bss : 0x%p" " - 0x%p" "   (%4td kB)\n",
520 
521 			MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
522 				(PAGE_SIZE)),
523 #ifdef CONFIG_HAVE_TCM
524 			MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
525 			MLK(ITCM_OFFSET, (unsigned long) itcm_end),
526 #endif
527 			MLK(FIXADDR_START, FIXADDR_END),
528 			MLM(VMALLOC_START, VMALLOC_END),
529 			MLM(PAGE_OFFSET, (unsigned long)high_memory),
530 #ifdef CONFIG_HIGHMEM
531 			MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
532 				(PAGE_SIZE)),
533 #endif
534 #ifdef CONFIG_MODULES
535 			MLM(MODULES_VADDR, MODULES_END),
536 #endif
537 
538 			MLK_ROUNDUP(_text, _etext),
539 			MLK_ROUNDUP(__init_begin, __init_end),
540 			MLK_ROUNDUP(_sdata, _edata),
541 			MLK_ROUNDUP(__bss_start, __bss_stop));
542 
543 #undef MLK
544 #undef MLM
545 #undef MLK_ROUNDUP
546 
547 	/*
548 	 * Check boundaries twice: Some fundamental inconsistencies can
549 	 * be detected at build time already.
550 	 */
551 #ifdef CONFIG_MMU
552 	BUILD_BUG_ON(TASK_SIZE				> MODULES_VADDR);
553 	BUG_ON(TASK_SIZE 				> MODULES_VADDR);
554 #endif
555 
556 #ifdef CONFIG_HIGHMEM
557 	BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
558 	BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE	> PAGE_OFFSET);
559 #endif
560 
561 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
562 		extern int sysctl_overcommit_memory;
563 		/*
564 		 * On a machine this small we won't get
565 		 * anywhere without overcommit, so turn
566 		 * it on by default.
567 		 */
568 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
569 	}
570 }
571 
572 #ifdef CONFIG_DEBUG_RODATA
573 struct section_perm {
574 	const char *name;
575 	unsigned long start;
576 	unsigned long end;
577 	pmdval_t mask;
578 	pmdval_t prot;
579 	pmdval_t clear;
580 };
581 
582 /* First section-aligned location at or after __start_rodata. */
583 extern char __start_rodata_section_aligned[];
584 
585 static struct section_perm nx_perms[] = {
586 	/* Make pages tables, etc before _stext RW (set NX). */
587 	{
588 		.name	= "pre-text NX",
589 		.start	= PAGE_OFFSET,
590 		.end	= (unsigned long)_stext,
591 		.mask	= ~PMD_SECT_XN,
592 		.prot	= PMD_SECT_XN,
593 	},
594 	/* Make init RW (set NX). */
595 	{
596 		.name	= "init NX",
597 		.start	= (unsigned long)__init_begin,
598 		.end	= (unsigned long)_sdata,
599 		.mask	= ~PMD_SECT_XN,
600 		.prot	= PMD_SECT_XN,
601 	},
602 	/* Make rodata NX (set RO in ro_perms below). */
603 	{
604 		.name	= "rodata NX",
605 		.start  = (unsigned long)__start_rodata_section_aligned,
606 		.end    = (unsigned long)__init_begin,
607 		.mask   = ~PMD_SECT_XN,
608 		.prot   = PMD_SECT_XN,
609 	},
610 };
611 
612 static struct section_perm ro_perms[] = {
613 	/* Make kernel code and rodata RX (set RO). */
614 	{
615 		.name	= "text/rodata RO",
616 		.start  = (unsigned long)_stext,
617 		.end    = (unsigned long)__init_begin,
618 #ifdef CONFIG_ARM_LPAE
619 		.mask   = ~L_PMD_SECT_RDONLY,
620 		.prot   = L_PMD_SECT_RDONLY,
621 #else
622 		.mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
623 		.prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,
624 		.clear  = PMD_SECT_AP_WRITE,
625 #endif
626 	},
627 };
628 
629 /*
630  * Updates section permissions only for the current mm (sections are
631  * copied into each mm). During startup, this is the init_mm. Is only
632  * safe to be called with preemption disabled, as under stop_machine().
633  */
634 static inline void section_update(unsigned long addr, pmdval_t mask,
635 				  pmdval_t prot, struct mm_struct *mm)
636 {
637 	pmd_t *pmd;
638 
639 	pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
640 
641 #ifdef CONFIG_ARM_LPAE
642 	pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
643 #else
644 	if (addr & SECTION_SIZE)
645 		pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
646 	else
647 		pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
648 #endif
649 	flush_pmd_entry(pmd);
650 	local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
651 }
652 
653 /* Make sure extended page tables are in use. */
654 static inline bool arch_has_strict_perms(void)
655 {
656 	if (cpu_architecture() < CPU_ARCH_ARMv6)
657 		return false;
658 
659 	return !!(get_cr() & CR_XP);
660 }
661 
662 void set_section_perms(struct section_perm *perms, int n, bool set,
663 			struct mm_struct *mm)
664 {
665 	size_t i;
666 	unsigned long addr;
667 
668 	if (!arch_has_strict_perms())
669 		return;
670 
671 	for (i = 0; i < n; i++) {
672 		if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
673 		    !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
674 			pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
675 				perms[i].name, perms[i].start, perms[i].end,
676 				SECTION_SIZE);
677 			continue;
678 		}
679 
680 		for (addr = perms[i].start;
681 		     addr < perms[i].end;
682 		     addr += SECTION_SIZE)
683 			section_update(addr, perms[i].mask,
684 				set ? perms[i].prot : perms[i].clear, mm);
685 	}
686 
687 }
688 
689 static void update_sections_early(struct section_perm perms[], int n)
690 {
691 	struct task_struct *t, *s;
692 
693 	read_lock(&tasklist_lock);
694 	for_each_process(t) {
695 		if (t->flags & PF_KTHREAD)
696 			continue;
697 		for_each_thread(t, s)
698 			set_section_perms(perms, n, true, s->mm);
699 	}
700 	read_unlock(&tasklist_lock);
701 	set_section_perms(perms, n, true, current->active_mm);
702 	set_section_perms(perms, n, true, &init_mm);
703 }
704 
705 int __fix_kernmem_perms(void *unused)
706 {
707 	update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
708 	return 0;
709 }
710 
711 void fix_kernmem_perms(void)
712 {
713 	stop_machine(__fix_kernmem_perms, NULL, NULL);
714 }
715 
716 int __mark_rodata_ro(void *unused)
717 {
718 	update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
719 	return 0;
720 }
721 
722 void mark_rodata_ro(void)
723 {
724 	stop_machine(__mark_rodata_ro, NULL, NULL);
725 }
726 
727 void set_kernel_text_rw(void)
728 {
729 	set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
730 				current->active_mm);
731 }
732 
733 void set_kernel_text_ro(void)
734 {
735 	set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
736 				current->active_mm);
737 }
738 
739 #else
740 static inline void fix_kernmem_perms(void) { }
741 #endif /* CONFIG_DEBUG_RODATA */
742 
743 void free_tcmmem(void)
744 {
745 #ifdef CONFIG_HAVE_TCM
746 	extern char __tcm_start, __tcm_end;
747 
748 	poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
749 	free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
750 #endif
751 }
752 
753 void free_initmem(void)
754 {
755 	fix_kernmem_perms();
756 	free_tcmmem();
757 
758 	poison_init_mem(__init_begin, __init_end - __init_begin);
759 	if (!machine_is_integrator() && !machine_is_cintegrator())
760 		free_initmem_default(-1);
761 }
762 
763 #ifdef CONFIG_BLK_DEV_INITRD
764 
765 static int keep_initrd;
766 
767 void free_initrd_mem(unsigned long start, unsigned long end)
768 {
769 	if (!keep_initrd) {
770 		if (start == initrd_start)
771 			start = round_down(start, PAGE_SIZE);
772 		if (end == initrd_end)
773 			end = round_up(end, PAGE_SIZE);
774 
775 		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
776 		free_reserved_area((void *)start, (void *)end, -1, "initrd");
777 	}
778 }
779 
780 static int __init keepinitrd_setup(char *__unused)
781 {
782 	keep_initrd = 1;
783 	return 1;
784 }
785 
786 __setup("keepinitrd", keepinitrd_setup);
787 #endif
788