/*
   * Based on arch/arm/mm/flush.c
   *
   * Copyright (C) 1995-2002 Russell King
   * Copyright (C) 2012 ARM Ltd.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  #include <linux/export.h>
  #include <linux/mm.h>
  #include <linux/pagemap.h>
  
  #include <asm/cacheflush.h>
  #include <asm/cachetype.h>
  #include <asm/tlbflush.h>
  
  #include "mm.h"
  
  void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
  		       unsigned long end)
  {
  	if (vma->vm_flags & VM_EXEC)
  		__flush_icache_all();
  }
  
  static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  				unsigned long uaddr, void *kaddr,
  				unsigned long len)
  {
  	if (vma->vm_flags & VM_EXEC) {
  		unsigned long addr = (unsigned long)kaddr;
  		if (icache_is_aliasing()) {
  			__flush_dcache_area(kaddr, len);
  			__flush_icache_all();
  		} else {
  			flush_icache_range(addr, addr + len);
  		}
  	}
  }
  
  /*
   * Copy user data from/to a page which is mapped into a different processes
   * address space.  Really, we want to allow our "user space" model to handle
   * this.
   *
   * Note that this code needs to run on the current CPU.
   */
  void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  		       unsigned long uaddr, void *dst, const void *src,
  		       unsigned long len)
  {
  #ifdef CONFIG_SMP
  	preempt_disable();
  #endif
  	memcpy(dst, src, len);
  	flush_ptrace_access(vma, page, uaddr, dst, len);
  #ifdef CONFIG_SMP
  	preempt_enable();
  #endif
  }
  
  void __sync_icache_dcache(pte_t pte, unsigned long addr)
  {
  	struct page *page = pte_page(pte);
  
  	/* no flushing needed for anonymous pages */
  	if (!page_mapping(page))
  		return;
  
  	if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
  		__flush_dcache_area(page_address(page),
  				PAGE_SIZE << compound_order(page));
  		__flush_icache_all();
  	} else if (icache_is_aivivt()) {
  		__flush_icache_all();
  	}
  }
  
  /*
   * This function is called when a page has been modified by the kernel. Mark
   * it as dirty for later flushing when mapped in user space (if executable,
   * see __sync_icache_dcache).
   */
  void flush_dcache_page(struct page *page)
  {
  	if (test_bit(PG_dcache_clean, &page->flags))
  		clear_bit(PG_dcache_clean, &page->flags);
  }
  EXPORT_SYMBOL(flush_dcache_page);
  
  /*
   * Additional functions defined in assembly.
   */
  EXPORT_SYMBOL(flush_cache_all);
  EXPORT_SYMBOL(flush_icache_range);