arch/unicore32/mm/flush.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/arch/unicore32/mm/flush.c
   4  *
   5  * Code specific to PKUnity SoC and UniCore ISA
   6  *
   7  * Copyright (C) 2001-2010 GUAN Xue-tao
   8  */
   9 #include <linux/module.h>
  10 #include <linux/mm.h>
  11 #include <linux/pagemap.h>
  12
  13 #include <asm/cacheflush.h>
  14 #include <asm/tlbflush.h>
  15
  16 void flush_cache_mm(struct mm_struct *mm)
  17 {
  18 }
  19
  20 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
  21                 unsigned long end)
  22 {
  23         if (vma->vm_flags & VM_EXEC)
  24                 __flush_icache_all();
  25 }
  26
  27 void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr,
  28                 unsigned long pfn)
  29 {
  30 }
  31
  32 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  33                          unsigned long uaddr, void *kaddr, unsigned long len)
  34 {
  35         /* VIPT non-aliasing D-cache */
  36         if (vma->vm_flags & VM_EXEC) {
  37                 unsigned long addr = (unsigned long)kaddr;
  38
  39                 __cpuc_coherent_kern_range(addr, addr + len);
  40         }
  41 }
  42
  43 /*
  44  * Copy user data from/to a page which is mapped into a different
  45  * processes address space.  Really, we want to allow our "user
  46  * space" model to handle this.
  47  *
  48  * Note that this code needs to run on the current CPU.
  49  */
  50 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  51                        unsigned long uaddr, void *dst, const void *src,
  52                        unsigned long len)
  53 {
  54         memcpy(dst, src, len);
  55         flush_ptrace_access(vma, page, uaddr, dst, len);
  56 }
  57
  58 void __flush_dcache_page(struct address_space *mapping, struct page *page)
  59 {
  60         /*
  61          * Writeback any data associated with the kernel mapping of this
  62          * page.  This ensures that data in the physical page is mutually
  63          * coherent with the kernels mapping.
  64          */
  65         __cpuc_flush_kern_dcache_area(page_address(page), PAGE_SIZE);
  66 }
  67
  68 /*
  69  * Ensure cache coherency between kernel mapping and userspace mapping
  70  * of this page.
  71  */
  72 void flush_dcache_page(struct page *page)
  73 {
  74         struct address_space *mapping;
  75
  76         /*
  77          * The zero page is never written to, so never has any dirty
  78          * cache lines, and therefore never needs to be flushed.
  79          */
  80         if (page == ZERO_PAGE(0))
  81                 return;
  82
  83         mapping = page_mapping_file(page);
  84
  85         if (mapping && !mapping_mapped(mapping))
  86                 clear_bit(PG_dcache_clean, &page->flags);
  87         else {
  88                 __flush_dcache_page(mapping, page);
  89                 if (mapping)
  90                         __flush_icache_all();
  91                 set_bit(PG_dcache_clean, &page->flags);
  92         }
  93 }
  94 EXPORT_SYMBOL(flush_dcache_page);