1 // SPDX-License-Identifier: GPL-2.0-only
4 * Copyright (C) 1995 Linus Torvalds
6 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
18 #include <linux/hugetlb.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/init.h>
22 #include <linux/highmem.h>
23 #include <linux/pagemap.h>
24 #include <linux/pci.h>
25 #include <linux/pfn.h>
26 #include <linux/poison.h>
27 #include <linux/memblock.h>
28 #include <linux/proc_fs.h>
29 #include <linux/memory_hotplug.h>
30 #include <linux/initrd.h>
31 #include <linux/cpumask.h>
32 #include <linux/gfp.h>
35 #include <asm/bios_ebda.h>
36 #include <asm/processor.h>
37 #include <linux/uaccess.h>
39 #include <asm/fixmap.h>
40 #include <asm/e820/api.h>
44 #include <asm/tlbflush.h>
45 #include <asm/olpc_ofw.h>
46 #include <asm/pgalloc.h>
47 #include <asm/sections.h>
48 #include <asm/paravirt.h>
49 #include <asm/setup.h>
50 #include <asm/set_memory.h>
51 #include <asm/page_types.h>
52 #include <asm/cpu_entry_area.h>
54 #include <asm/pgtable_areas.h>
56 #include "mm_internal.h"
58 unsigned long highstart_pfn, highend_pfn;
60 bool __read_mostly __vmalloc_start_set = false;
63 * Creates a middle page table and puts a pointer to it in the
64 * given global directory entry. This only returns the gd entry
65 * in non-PAE compilation mode, since the middle layer is folded.
67 static pmd_t * __init one_md_table_init(pgd_t *pgd)
74 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
75 pmd_table = (pmd_t *)alloc_low_page();
76 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
77 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
78 p4d = p4d_offset(pgd, 0);
79 pud = pud_offset(p4d, 0);
80 BUG_ON(pmd_table != pmd_offset(pud, 0));
85 p4d = p4d_offset(pgd, 0);
86 pud = pud_offset(p4d, 0);
87 pmd_table = pmd_offset(pud, 0);
93 * Create a page table and place a pointer to it in a middle page
96 static pte_t * __init one_page_table_init(pmd_t *pmd)
98 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
99 pte_t *page_table = (pte_t *)alloc_low_page();
101 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
102 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
103 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
106 return pte_offset_kernel(pmd, 0);
109 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
111 int pgd_idx = pgd_index(vaddr);
112 int pmd_idx = pmd_index(vaddr);
114 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
117 pte_t * __init populate_extra_pte(unsigned long vaddr)
119 int pte_idx = pte_index(vaddr);
122 pmd = populate_extra_pmd(vaddr);
123 return one_page_table_init(pmd) + pte_idx;
126 static unsigned long __init
127 page_table_range_init_count(unsigned long start, unsigned long end)
129 unsigned long count = 0;
130 #ifdef CONFIG_HIGHMEM
131 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
132 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
133 int pgd_idx, pmd_idx;
136 if (pmd_idx_kmap_begin == pmd_idx_kmap_end)
140 pgd_idx = pgd_index(vaddr);
141 pmd_idx = pmd_index(vaddr);
143 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) {
144 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
146 if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin &&
147 (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end)
157 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
158 unsigned long vaddr, pte_t *lastpte,
161 #ifdef CONFIG_HIGHMEM
163 * Something (early fixmap) may already have put a pte
164 * page here, which causes the page table allocation
165 * to become nonlinear. Attempt to fix it, and if it
166 * is still nonlinear then we have to bug.
168 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
169 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
171 if (pmd_idx_kmap_begin != pmd_idx_kmap_end
172 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
173 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) {
177 BUG_ON(after_bootmem);
179 for (i = 0; i < PTRS_PER_PTE; i++)
180 set_pte(newpte + i, pte[i]);
181 *adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE);
183 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
184 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
185 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
188 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
191 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
192 && vaddr > fix_to_virt(FIX_KMAP_END)
193 && lastpte && lastpte + PTRS_PER_PTE != pte);
199 * This function initializes a certain range of kernel virtual memory
200 * with new bootmem page tables, everywhere page tables are missing in
203 * NOTE: The pagetables are allocated contiguous on the physical space
204 * so we can cache the place of the first one and move around without
205 * checking the pgd every time.
208 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
210 int pgd_idx, pmd_idx;
215 unsigned long count = page_table_range_init_count(start, end);
219 adr = alloc_low_pages(count);
222 pgd_idx = pgd_index(vaddr);
223 pmd_idx = pmd_index(vaddr);
224 pgd = pgd_base + pgd_idx;
226 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
227 pmd = one_md_table_init(pgd);
228 pmd = pmd + pmd_index(vaddr);
229 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
231 pte = page_table_kmap_check(one_page_table_init(pmd),
232 pmd, vaddr, pte, &adr);
241 * The <linux/kallsyms.h> already defines is_kernel_text,
242 * using '__' prefix not to get in conflict.
244 static inline int __is_kernel_text(unsigned long addr)
246 if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
252 * This maps the physical memory to kernel virtual address space, a total
253 * of max_low_pfn pages, by creating page tables starting from address
257 kernel_physical_mapping_init(unsigned long start,
259 unsigned long page_size_mask,
262 int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
263 unsigned long last_map_addr = end;
264 unsigned long start_pfn, end_pfn;
265 pgd_t *pgd_base = swapper_pg_dir;
266 int pgd_idx, pmd_idx, pte_ofs;
271 unsigned pages_2m, pages_4k;
274 start_pfn = start >> PAGE_SHIFT;
275 end_pfn = end >> PAGE_SHIFT;
278 * First iteration will setup identity mapping using large/small pages
279 * based on use_pse, with other attributes same as set by
280 * the early code in head_32.S
282 * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
283 * as desired for the kernel identity mapping.
285 * This two pass mechanism conforms to the TLB app note which says:
287 * "Software should not write to a paging-structure entry in a way
288 * that would change, for any linear address, both the page size
289 * and either the page frame or attributes."
293 if (!boot_cpu_has(X86_FEATURE_PSE))
297 pages_2m = pages_4k = 0;
299 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
300 pgd = pgd_base + pgd_idx;
301 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
302 pmd = one_md_table_init(pgd);
306 #ifdef CONFIG_X86_PAE
307 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
312 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
314 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
317 * Map with big pages if possible, otherwise
318 * create normal page tables:
322 pgprot_t prot = PAGE_KERNEL_LARGE;
324 * first pass will use the same initial
325 * identity mapping attribute + _PAGE_PSE.
328 __pgprot(PTE_IDENT_ATTR |
331 pfn &= PMD_MASK >> PAGE_SHIFT;
332 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
333 PAGE_OFFSET + PAGE_SIZE-1;
335 if (__is_kernel_text(addr) ||
336 __is_kernel_text(addr2))
337 prot = PAGE_KERNEL_LARGE_EXEC;
340 if (mapping_iter == 1)
341 set_pmd(pmd, pfn_pmd(pfn, init_prot));
343 set_pmd(pmd, pfn_pmd(pfn, prot));
348 pte = one_page_table_init(pmd);
350 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
352 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
353 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
354 pgprot_t prot = PAGE_KERNEL;
356 * first pass will use the same initial
357 * identity mapping attribute.
359 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
361 if (__is_kernel_text(addr))
362 prot = PAGE_KERNEL_EXEC;
365 if (mapping_iter == 1) {
366 set_pte(pte, pfn_pte(pfn, init_prot));
367 last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
369 set_pte(pte, pfn_pte(pfn, prot));
373 if (mapping_iter == 1) {
375 * update direct mapping page count only in the first
378 update_page_count(PG_LEVEL_2M, pages_2m);
379 update_page_count(PG_LEVEL_4K, pages_4k);
382 * local global flush tlb, which will flush the previous
383 * mappings present in both small and large page TLB's.
388 * Second iteration will set the actual desired PTE attributes.
393 return last_map_addr;
398 static void __init kmap_init(void)
400 unsigned long kmap_vstart;
403 * Cache the first kmap pte:
405 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
406 kmap_pte = virt_to_kpte(kmap_vstart);
409 #ifdef CONFIG_HIGHMEM
410 static void __init permanent_kmaps_init(pgd_t *pgd_base)
412 unsigned long vaddr = PKMAP_BASE;
414 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
416 pkmap_page_table = virt_to_kpte(vaddr);
419 void __init add_highpages_with_active_regions(int nid,
420 unsigned long start_pfn, unsigned long end_pfn)
422 phys_addr_t start, end;
425 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) {
426 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start),
428 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end),
430 for ( ; pfn < e_pfn; pfn++)
432 free_highmem_page(pfn_to_page(pfn));
436 static inline void permanent_kmaps_init(pgd_t *pgd_base)
439 #endif /* CONFIG_HIGHMEM */
441 void __init sync_initial_page_table(void)
443 clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
444 swapper_pg_dir + KERNEL_PGD_BOUNDARY,
448 * sync back low identity map too. It is used for example
449 * in the 32-bit EFI stub.
451 clone_pgd_range(initial_page_table,
452 swapper_pg_dir + KERNEL_PGD_BOUNDARY,
453 min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
456 void __init native_pagetable_init(void)
458 unsigned long pfn, va;
459 pgd_t *pgd, *base = swapper_pg_dir;
466 * Remove any mappings which extend past the end of physical
467 * memory from the boot time page table.
468 * In virtual address space, we should have at least two pages
469 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
470 * definition. And max_low_pfn is set to VMALLOC_END physical
471 * address. If initial memory mapping is doing right job, we
472 * should have pte used near max_low_pfn or one pmd is not present.
474 for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
475 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
476 pgd = base + pgd_index(va);
477 if (!pgd_present(*pgd))
480 p4d = p4d_offset(pgd, va);
481 pud = pud_offset(p4d, va);
482 pmd = pmd_offset(pud, va);
483 if (!pmd_present(*pmd))
486 /* should not be large page here */
487 if (pmd_large(*pmd)) {
488 pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n",
489 pfn, pmd, __pa(pmd));
493 pte = pte_offset_kernel(pmd, va);
494 if (!pte_present(*pte))
497 printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
498 pfn, pmd, __pa(pmd), pte, __pa(pte));
499 pte_clear(NULL, va, pte);
501 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
506 * Build a proper pagetable for the kernel mappings. Up until this
507 * point, we've been running on some set of pagetables constructed by
510 * If we're booting on native hardware, this will be a pagetable
511 * constructed in arch/x86/kernel/head_32.S. The root of the
512 * pagetable will be swapper_pg_dir.
514 * If we're booting paravirtualized under a hypervisor, then there are
515 * more options: we may already be running PAE, and the pagetable may
516 * or may not be based in swapper_pg_dir. In any case,
517 * paravirt_pagetable_init() will set up swapper_pg_dir
518 * appropriately for the rest of the initialization to work.
520 * In general, pagetable_init() assumes that the pagetable may already
521 * be partially populated, and so it avoids stomping on any existing
524 void __init early_ioremap_page_table_range_init(void)
526 pgd_t *pgd_base = swapper_pg_dir;
527 unsigned long vaddr, end;
530 * Fixed mappings, only the page table structure has to be
531 * created - mappings will be set by set_fixmap():
533 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
534 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
535 page_table_range_init(vaddr, end, pgd_base);
536 early_ioremap_reset();
539 static void __init pagetable_init(void)
541 pgd_t *pgd_base = swapper_pg_dir;
543 permanent_kmaps_init(pgd_base);
546 #define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL)
547 /* Bits supported by the hardware: */
548 pteval_t __supported_pte_mask __read_mostly = DEFAULT_PTE_MASK;
549 /* Bits allowed in normal kernel mappings: */
550 pteval_t __default_kernel_pte_mask __read_mostly = DEFAULT_PTE_MASK;
551 EXPORT_SYMBOL_GPL(__supported_pte_mask);
552 /* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
553 EXPORT_SYMBOL(__default_kernel_pte_mask);
555 /* user-defined highmem size */
556 static unsigned int highmem_pages = -1;
559 * highmem=size forces highmem to be exactly 'size' bytes.
560 * This works even on boxes that have no highmem otherwise.
561 * This also works to reduce highmem size on bigger boxes.
563 static int __init parse_highmem(char *arg)
568 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
571 early_param("highmem", parse_highmem);
573 #define MSG_HIGHMEM_TOO_BIG \
574 "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
576 #define MSG_LOWMEM_TOO_SMALL \
577 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
579 * All of RAM fits into lowmem - but if user wants highmem
580 * artificially via the highmem=x boot parameter then create
583 static void __init lowmem_pfn_init(void)
585 /* max_low_pfn is 0, we already have early_res support */
586 max_low_pfn = max_pfn;
588 if (highmem_pages == -1)
590 #ifdef CONFIG_HIGHMEM
591 if (highmem_pages >= max_pfn) {
592 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
593 pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
597 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
598 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
599 pages_to_mb(highmem_pages));
602 max_low_pfn -= highmem_pages;
606 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
610 #define MSG_HIGHMEM_TOO_SMALL \
611 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
613 #define MSG_HIGHMEM_TRIMMED \
614 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
616 * We have more RAM than fits into lowmem - we try to put it into
617 * highmem, also taking the highmem=x boot parameter into account:
619 static void __init highmem_pfn_init(void)
621 max_low_pfn = MAXMEM_PFN;
623 if (highmem_pages == -1)
624 highmem_pages = max_pfn - MAXMEM_PFN;
626 if (highmem_pages + MAXMEM_PFN < max_pfn)
627 max_pfn = MAXMEM_PFN + highmem_pages;
629 if (highmem_pages + MAXMEM_PFN > max_pfn) {
630 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
631 pages_to_mb(max_pfn - MAXMEM_PFN),
632 pages_to_mb(highmem_pages));
635 #ifndef CONFIG_HIGHMEM
636 /* Maximum memory usable is what is directly addressable */
637 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
638 if (max_pfn > MAX_NONPAE_PFN)
639 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
641 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
642 max_pfn = MAXMEM_PFN;
643 #else /* !CONFIG_HIGHMEM */
644 #ifndef CONFIG_HIGHMEM64G
645 if (max_pfn > MAX_NONPAE_PFN) {
646 max_pfn = MAX_NONPAE_PFN;
647 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
649 #endif /* !CONFIG_HIGHMEM64G */
650 #endif /* !CONFIG_HIGHMEM */
654 * Determine low and high memory ranges:
656 void __init find_low_pfn_range(void)
658 /* it could update max_pfn */
660 if (max_pfn <= MAXMEM_PFN)
666 #ifndef CONFIG_NEED_MULTIPLE_NODES
667 void __init initmem_init(void)
669 #ifdef CONFIG_HIGHMEM
670 highstart_pfn = highend_pfn = max_pfn;
671 if (max_pfn > max_low_pfn)
672 highstart_pfn = max_low_pfn;
673 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
674 pages_to_mb(highend_pfn - highstart_pfn));
675 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
677 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
680 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
681 sparse_memory_present_with_active_regions(0);
683 #ifdef CONFIG_FLATMEM
684 max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn;
686 __vmalloc_start_set = true;
688 printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
689 pages_to_mb(max_low_pfn));
691 setup_bootmem_allocator();
693 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
695 void __init setup_bootmem_allocator(void)
697 printk(KERN_INFO " mapped low ram: 0 - %08lx\n",
698 max_pfn_mapped<<PAGE_SHIFT);
699 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
703 * paging_init() sets up the page tables - note that the first 8MB are
704 * already mapped by head.S.
706 * This routines also unmaps the page at virtual kernel address 0, so
707 * that we can trap those pesky NULL-reference errors in the kernel.
709 void __init paging_init(void)
718 * NOTE: at this point the bootmem allocator is fully available.
720 olpc_dt_build_devicetree();
721 sparse_memory_present_with_active_regions(MAX_NUMNODES);
727 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
728 * and also on some strange 486's. All 586+'s are OK. This used to involve
729 * black magic jumps to work around some nasty CPU bugs, but fortunately the
730 * switch to using exceptions got rid of all that.
732 static void __init test_wp_bit(void)
736 printk(KERN_INFO "Checking if this processor honours the WP bit even in supervisor mode...");
738 __set_fixmap(FIX_WP_TEST, __pa_symbol(empty_zero_page), PAGE_KERNEL_RO);
740 if (copy_to_kernel_nofault((char *)fix_to_virt(FIX_WP_TEST), &z, 1)) {
741 clear_fixmap(FIX_WP_TEST);
742 printk(KERN_CONT "Ok.\n");
746 printk(KERN_CONT "No.\n");
747 panic("Linux doesn't support CPUs with broken WP.");
750 void __init mem_init(void)
754 #ifdef CONFIG_FLATMEM
758 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to
759 * be done before memblock_free_all(). Memblock use free low memory for
760 * temporary data (see find_range_array()) and for this purpose can use
761 * pages that was already passed to the buddy allocator, hence marked as
762 * not accessible in the page tables when compiled with
763 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not
766 set_highmem_pages_init();
768 /* this will put all low memory onto the freelists */
772 x86_init.hyper.init_after_bootmem();
774 mem_init_print_info(NULL);
777 * Check boundaries twice: Some fundamental inconsistencies can
778 * be detected at build time already.
780 #define __FIXADDR_TOP (-PAGE_SIZE)
781 #ifdef CONFIG_HIGHMEM
782 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
783 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE);
785 #define high_memory (-128UL << 20)
786 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
790 #ifdef CONFIG_HIGHMEM
791 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
792 BUG_ON(VMALLOC_END > PKMAP_BASE);
794 BUG_ON(VMALLOC_START >= VMALLOC_END);
795 BUG_ON((unsigned long)high_memory > VMALLOC_START);
800 #ifdef CONFIG_MEMORY_HOTPLUG
801 int arch_add_memory(int nid, u64 start, u64 size,
802 struct mhp_params *params)
804 unsigned long start_pfn = start >> PAGE_SHIFT;
805 unsigned long nr_pages = size >> PAGE_SHIFT;
809 * The page tables were already mapped at boot so if the caller
810 * requests a different mapping type then we must change all the
811 * pages with __set_memory_prot().
813 if (params->pgprot.pgprot != PAGE_KERNEL.pgprot) {
814 ret = __set_memory_prot(start, nr_pages, params->pgprot);
819 return __add_pages(nid, start_pfn, nr_pages, params);
822 void arch_remove_memory(int nid, u64 start, u64 size,
823 struct vmem_altmap *altmap)
825 unsigned long start_pfn = start >> PAGE_SHIFT;
826 unsigned long nr_pages = size >> PAGE_SHIFT;
828 __remove_pages(start_pfn, nr_pages, altmap);
832 int kernel_set_to_readonly __read_mostly;
834 static void mark_nxdata_nx(void)
837 * When this called, init has already been executed and released,
838 * so everything past _etext should be NX.
840 unsigned long start = PFN_ALIGN(_etext);
842 * This comes from __is_kernel_text upper limit. Also HPAGE where used:
844 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
846 if (__supported_pte_mask & _PAGE_NX)
847 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
848 set_memory_nx(start, size >> PAGE_SHIFT);
851 void mark_rodata_ro(void)
853 unsigned long start = PFN_ALIGN(_text);
854 unsigned long size = (unsigned long)__end_rodata - start;
856 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
857 pr_info("Write protecting kernel text and read-only data: %luk\n",
860 kernel_set_to_readonly = 1;
862 #ifdef CONFIG_CPA_DEBUG
863 pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size);
864 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
866 pr_info("Testing CPA: write protecting again\n");
867 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
870 if (__supported_pte_mask & _PAGE_NX)