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229 lines
5.4 KiB
229 lines
5.4 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* This file contains the routines setting up the linux page tables. |
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* -- paulus |
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* |
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* Derived from arch/ppc/mm/init.c: |
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* Copyright (C) 1995-1996 Gary Thomas ([email protected]) |
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* |
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* Modifications by Paul Mackerras (PowerMac) ([email protected]) |
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* and Cort Dougan (PReP) ([email protected]) |
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* Copyright (C) 1996 Paul Mackerras |
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* |
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* Derived from "arch/i386/mm/init.c" |
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/mm.h> |
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#include <linux/vmalloc.h> |
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#include <linux/init.h> |
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#include <linux/highmem.h> |
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#include <linux/memblock.h> |
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#include <linux/slab.h> |
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#include <asm/pgalloc.h> |
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#include <asm/fixmap.h> |
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#include <asm/setup.h> |
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#include <asm/sections.h> |
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#include <asm/early_ioremap.h> |
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#include <mm/mmu_decl.h> |
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extern char etext[], _stext[], _sinittext[], _einittext[]; |
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static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data; |
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notrace void __init early_ioremap_init(void) |
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{ |
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unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE); |
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pte_t *ptep = (pte_t *)early_fixmap_pagetable; |
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pmd_t *pmdp = pmd_off_k(addr); |
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for (; (s32)(FIXADDR_TOP - addr) > 0; |
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addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++) |
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pmd_populate_kernel(&init_mm, pmdp, ptep); |
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early_ioremap_setup(); |
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} |
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static void __init *early_alloc_pgtable(unsigned long size) |
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{ |
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void *ptr = memblock_alloc(size, size); |
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if (!ptr) |
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panic("%s: Failed to allocate %lu bytes align=0x%lx\n", |
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__func__, size, size); |
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return ptr; |
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} |
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pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va) |
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{ |
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if (pmd_none(*pmdp)) { |
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pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE); |
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pmd_populate_kernel(&init_mm, pmdp, ptep); |
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} |
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return pte_offset_kernel(pmdp, va); |
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} |
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int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot) |
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{ |
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pmd_t *pd; |
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pte_t *pg; |
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int err = -ENOMEM; |
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/* Use upper 10 bits of VA to index the first level map */ |
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pd = pmd_off_k(va); |
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/* Use middle 10 bits of VA to index the second-level map */ |
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if (likely(slab_is_available())) |
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pg = pte_alloc_kernel(pd, va); |
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else |
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pg = early_pte_alloc_kernel(pd, va); |
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if (pg) { |
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err = 0; |
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/* The PTE should never be already set nor present in the |
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* hash table |
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*/ |
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BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot)); |
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set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot)); |
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} |
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smp_wmb(); |
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return err; |
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} |
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/* |
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* Map in a chunk of physical memory starting at start. |
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*/ |
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static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) |
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{ |
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unsigned long v, s; |
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phys_addr_t p; |
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int ktext; |
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s = offset; |
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v = PAGE_OFFSET + s; |
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p = memstart_addr + s; |
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for (; s < top; s += PAGE_SIZE) { |
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ktext = ((char *)v >= _stext && (char *)v < etext) || |
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((char *)v >= _sinittext && (char *)v < _einittext); |
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map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL); |
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v += PAGE_SIZE; |
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p += PAGE_SIZE; |
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} |
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} |
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void __init mapin_ram(void) |
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{ |
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phys_addr_t base, end; |
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u64 i; |
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for_each_mem_range(i, &base, &end) { |
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phys_addr_t top = min(end, total_lowmem); |
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if (base >= top) |
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continue; |
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base = mmu_mapin_ram(base, top); |
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__mapin_ram_chunk(base, top); |
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} |
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} |
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static int __change_page_attr_noflush(struct page *page, pgprot_t prot) |
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{ |
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pte_t *kpte; |
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unsigned long address; |
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BUG_ON(PageHighMem(page)); |
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address = (unsigned long)page_address(page); |
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if (v_block_mapped(address)) |
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return 0; |
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kpte = virt_to_kpte(address); |
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if (!kpte) |
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return -EINVAL; |
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__set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); |
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return 0; |
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} |
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/* |
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* Change the page attributes of an page in the linear mapping. |
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* |
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* THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY |
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*/ |
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static int change_page_attr(struct page *page, int numpages, pgprot_t prot) |
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{ |
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int i, err = 0; |
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unsigned long flags; |
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struct page *start = page; |
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local_irq_save(flags); |
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for (i = 0; i < numpages; i++, page++) { |
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err = __change_page_attr_noflush(page, prot); |
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if (err) |
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break; |
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} |
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wmb(); |
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local_irq_restore(flags); |
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flush_tlb_kernel_range((unsigned long)page_address(start), |
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(unsigned long)page_address(page)); |
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return err; |
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} |
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void mark_initmem_nx(void) |
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{ |
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struct page *page = virt_to_page(_sinittext); |
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unsigned long numpages = PFN_UP((unsigned long)_einittext) - |
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PFN_DOWN((unsigned long)_sinittext); |
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if (v_block_mapped((unsigned long)_sinittext)) |
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mmu_mark_initmem_nx(); |
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else |
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change_page_attr(page, numpages, PAGE_KERNEL); |
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} |
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#ifdef CONFIG_STRICT_KERNEL_RWX |
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void mark_rodata_ro(void) |
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{ |
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struct page *page; |
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unsigned long numpages; |
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if (v_block_mapped((unsigned long)_stext + 1)) { |
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mmu_mark_rodata_ro(); |
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ptdump_check_wx(); |
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return; |
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} |
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page = virt_to_page(_stext); |
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numpages = PFN_UP((unsigned long)_etext) - |
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PFN_DOWN((unsigned long)_stext); |
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change_page_attr(page, numpages, PAGE_KERNEL_ROX); |
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/* |
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* mark .rodata as read only. Use __init_begin rather than __end_rodata |
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* to cover NOTES and EXCEPTION_TABLE. |
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*/ |
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page = virt_to_page(__start_rodata); |
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numpages = PFN_UP((unsigned long)__init_begin) - |
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PFN_DOWN((unsigned long)__start_rodata); |
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change_page_attr(page, numpages, PAGE_KERNEL_RO); |
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// mark_initmem_nx() should have already run by now |
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ptdump_check_wx(); |
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} |
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#endif |
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#ifdef CONFIG_DEBUG_PAGEALLOC |
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void __kernel_map_pages(struct page *page, int numpages, int enable) |
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{ |
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if (PageHighMem(page)) |
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return; |
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change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); |
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} |
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#endif /* CONFIG_DEBUG_PAGEALLOC */
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