mirror of https://gitee.com/openkylin/linux.git
95 lines
2.0 KiB
C
95 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/compiler.h>
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#include <linux/init.h>
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#include <linux/export.h>
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#include <linux/highmem.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <asm/fixmap.h>
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#include <asm/tlbflush.h>
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static pte_t *kmap_pte;
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unsigned long highstart_pfn, highend_pfn;
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void kmap_flush_tlb(unsigned long addr)
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{
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flush_tlb_one(addr);
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}
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EXPORT_SYMBOL(kmap_flush_tlb);
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void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
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{
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unsigned long vaddr;
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int idx, type;
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type = kmap_atomic_idx_push();
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idx = type + KM_TYPE_NR*smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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#ifdef CONFIG_DEBUG_HIGHMEM
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BUG_ON(!pte_none(*(kmap_pte - idx)));
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#endif
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set_pte(kmap_pte-idx, mk_pte(page, prot));
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local_flush_tlb_one((unsigned long)vaddr);
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return (void*) vaddr;
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}
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EXPORT_SYMBOL(kmap_atomic_high_prot);
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void kunmap_atomic_high(void *kvaddr)
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{
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unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
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int type __maybe_unused;
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if (vaddr < FIXADDR_START)
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return;
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type = kmap_atomic_idx();
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#ifdef CONFIG_DEBUG_HIGHMEM
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{
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int idx = type + KM_TYPE_NR * smp_processor_id();
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BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
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/*
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* force other mappings to Oops if they'll try to access
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* this pte without first remap it
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*/
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pte_clear(&init_mm, vaddr, kmap_pte-idx);
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local_flush_tlb_one(vaddr);
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}
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#endif
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kmap_atomic_idx_pop();
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}
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EXPORT_SYMBOL(kunmap_atomic_high);
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/*
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* This is the same as kmap_atomic() but can map memory that doesn't
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* have a struct page associated with it.
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*/
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void *kmap_atomic_pfn(unsigned long pfn)
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{
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unsigned long vaddr;
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int idx, type;
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preempt_disable();
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pagefault_disable();
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type = kmap_atomic_idx_push();
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idx = type + KM_TYPE_NR*smp_processor_id();
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vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
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set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
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flush_tlb_one(vaddr);
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return (void*) vaddr;
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}
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void __init kmap_init(void)
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{
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unsigned long kmap_vstart;
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/* cache the first kmap pte */
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kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
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kmap_pte = virt_to_kpte(kmap_vstart);
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}
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