Eric Lee / smarc-fsl-linux-kernel

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arch/nds32/mm/highmem.c 1.62 KB
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59fd53cd5   Greentime Hu   nds32: MMU initia... 
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  // SPDX-License-Identifier: GPL-2.0
  // Copyright (C) 2005-2017 Andes Technology Corporation
  
  #include <linux/export.h>
  #include <linux/highmem.h>
  #include <linux/sched.h>
  #include <linux/smp.h>
  #include <linux/interrupt.h>
57c8a661d   Mike Rapoport   mm: remove includ... 
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  #include <linux/memblock.h>
59fd53cd5   Greentime Hu   nds32: MMU initia... 
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  #include <asm/fixmap.h>
  #include <asm/tlbflush.h>
  
  void *kmap(struct page *page)
  {
  	unsigned long vaddr;
  	might_sleep();
  	if (!PageHighMem(page))
  		return page_address(page);
  	vaddr = (unsigned long)kmap_high(page);
  	return (void *)vaddr;
  }
  
  EXPORT_SYMBOL(kmap);
  
  void kunmap(struct page *page)
  {
  	BUG_ON(in_interrupt());
  	if (!PageHighMem(page))
  		return;
  	kunmap_high(page);
  }
  
  EXPORT_SYMBOL(kunmap);
  
  void *kmap_atomic(struct page *page)
  {
  	unsigned int idx;
  	unsigned long vaddr, pte;
  	int type;
  	pte_t *ptep;
  
  	preempt_disable();
  	pagefault_disable();
  	if (!PageHighMem(page))
  		return page_address(page);
  
  	type = kmap_atomic_idx_push();
  
  	idx = type + KM_TYPE_NR * smp_processor_id();
  	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
  	pte = (page_to_pfn(page) << PAGE_SHIFT) | (PAGE_KERNEL);
  	ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
  	set_pte(ptep, pte);
  
  	__nds32__tlbop_inv(vaddr);
  	__nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);
  	__nds32__tlbop_rwr(pte);
  	__nds32__isb();
  	return (void *)vaddr;
  }
  
  EXPORT_SYMBOL(kmap_atomic);
  
  void __kunmap_atomic(void *kvaddr)
  {
  	if (kvaddr >= (void *)FIXADDR_START) {
  		unsigned long vaddr = (unsigned long)kvaddr;
  		pte_t *ptep;
  		kmap_atomic_idx_pop();
  		__nds32__tlbop_inv(vaddr);
  		__nds32__isb();
  		ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
  		set_pte(ptep, 0);
  	}
  	pagefault_enable();
  	preempt_enable();
  }
  
  EXPORT_SYMBOL(__kunmap_atomic);