arch/unicore32/mm/flush.c

   1 /*
   2  * linux/arch/unicore32/mm/flush.c
   3  *
   4  * Code specific to PKUnity SoC and UniCore ISA
   5  *
   6  * Copyright (C) 2001-2010 GUAN Xue-tao
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/mm.h>
  14 #include <linux/pagemap.h>
  15
  16 #include <asm/cacheflush.h>
  17 #include <asm/tlbflush.h>
  18
  19 void flush_cache_mm(struct mm_struct *mm)
  20 {
  21 }
  22
  23 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
  24                 unsigned long end)
  25 {
  26         if (vma->vm_flags & VM_EXEC)
  27                 __flush_icache_all();
  28 }
  29
  30 void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr,
  31                 unsigned long pfn)
  32 {
  33 }
  34
  35 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  36                          unsigned long uaddr, void *kaddr, unsigned long len)
  37 {
  38         /* VIPT non-aliasing D-cache */
  39         if (vma->vm_flags & VM_EXEC) {
  40                 unsigned long addr = (unsigned long)kaddr;
  41
  42                 __cpuc_coherent_kern_range(addr, addr + len);
  43         }
  44 }
  45
  46 /*
  47  * Copy user data from/to a page which is mapped into a different
  48  * processes address space.  Really, we want to allow our "user
  49  * space" model to handle this.
  50  *
  51  * Note that this code needs to run on the current CPU.
  52  */
  53 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  54                        unsigned long uaddr, void *dst, const void *src,
  55                        unsigned long len)
  56 {
  57         memcpy(dst, src, len);
  58         flush_ptrace_access(vma, page, uaddr, dst, len);
  59 }
  60
  61 void __flush_dcache_page(struct address_space *mapping, struct page *page)
  62 {
  63         /*
  64          * Writeback any data associated with the kernel mapping of this
  65          * page.  This ensures that data in the physical page is mutually
  66          * coherent with the kernels mapping.
  67          */
  68         __cpuc_flush_kern_dcache_area(page_address(page), PAGE_SIZE);
  69 }
  70
  71 /*
  72  * Ensure cache coherency between kernel mapping and userspace mapping
  73  * of this page.
  74  */
  75 void flush_dcache_page(struct page *page)
  76 {
  77         struct address_space *mapping;
  78
  79         /*
  80          * The zero page is never written to, so never has any dirty
  81          * cache lines, and therefore never needs to be flushed.
  82          */
  83         if (page == ZERO_PAGE(0))
  84                 return;
  85
  86         mapping = page_mapping(page);
  87
  88         if (mapping && !mapping_mapped(mapping))
  89                 clear_bit(PG_dcache_clean, &page->flags);
  90         else {
  91                 __flush_dcache_page(mapping, page);
  92                 if (mapping)
  93                         __flush_icache_all();
  94                 set_bit(PG_dcache_clean, &page->flags);
  95         }
  96 }
  97 EXPORT_SYMBOL(flush_dcache_page);