arch/arm64/mm/flush.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Based on arch/arm/mm/flush.c
   4  *
   5  * Copyright (C) 1995-2002 Russell King
   6  * Copyright (C) 2012 ARM Ltd.
   7  */
   8
   9 #include <linux/export.h>
  10 #include <linux/mm.h>
  11 #include <linux/pagemap.h>
  12
  13 #include <asm/cacheflush.h>
  14 #include <asm/cache.h>
  15 #include <asm/tlbflush.h>
  16
  17 void sync_icache_aliases(void *kaddr, unsigned long len)
  18 {
  19         unsigned long addr = (unsigned long)kaddr;
  20
  21         if (icache_is_aliasing()) {
  22                 __clean_dcache_area_pou(kaddr, len);
  23                 __flush_icache_all();
  24         } else {
  25                 /*
  26                  * Don't issue kick_all_cpus_sync() after I-cache invalidation
  27                  * for user mappings.
  28                  */
  29                 __flush_icache_range(addr, addr + len);
  30         }
  31 }
  32
  33 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  34                                 unsigned long uaddr, void *kaddr,
  35                                 unsigned long len)
  36 {
  37         if (vma->vm_flags & VM_EXEC)
  38                 sync_icache_aliases(kaddr, len);
  39 }
  40
  41 /*
  42  * Copy user data from/to a page which is mapped into a different processes
  43  * address space.  Really, we want to allow our "user space" model to handle
  44  * this.
  45  */
  46 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  47                        unsigned long uaddr, void *dst, const void *src,
  48                        unsigned long len)
  49 {
  50         memcpy(dst, src, len);
  51         flush_ptrace_access(vma, page, uaddr, dst, len);
  52 }
  53
  54 void __sync_icache_dcache(pte_t pte)
  55 {
  56         struct page *page = pte_page(pte);
  57
  58         if (!test_and_set_bit(PG_dcache_clean, &page->flags))
  59                 sync_icache_aliases(page_address(page),
  60                                     PAGE_SIZE << compound_order(page));
  61 }
  62 EXPORT_SYMBOL_GPL(__sync_icache_dcache);
  63
  64 /*
  65  * This function is called when a page has been modified by the kernel. Mark
  66  * it as dirty for later flushing when mapped in user space (if executable,
  67  * see __sync_icache_dcache).
  68  */
  69 void flush_dcache_page(struct page *page)
  70 {
  71         if (test_bit(PG_dcache_clean, &page->flags))
  72                 clear_bit(PG_dcache_clean, &page->flags);
  73 }
  74 EXPORT_SYMBOL(flush_dcache_page);
  75
  76 /*
  77  * Additional functions defined in assembly.
  78  */
  79 EXPORT_SYMBOL(__flush_icache_range);
  80
  81 #ifdef CONFIG_ARCH_HAS_PMEM_API
  82 void arch_wb_cache_pmem(void *addr, size_t size)
  83 {
  84         /* Ensure order against any prior non-cacheable writes */
  85         dmb(osh);
  86         __clean_dcache_area_pop(addr, size);
  87 }
  88 EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);
  89
  90 void arch_invalidate_pmem(void *addr, size_t size)
  91 {
  92         __inval_dcache_area(addr, size);
  93 }
  94 EXPORT_SYMBOL_GPL(arch_invalidate_pmem);
  95 #endif