/*
   * arch/sh/mm/cache-sh7705.c
   *
   * Copyright (C) 1999, 2000  Niibe Yutaka
   * Copyright (C) 2004  Alex Song
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   */
  #include <linux/init.h>
  #include <linux/mman.h>
  #include <linux/mm.h>
  #include <linux/fs.h>
  #include <linux/threads.h>
  #include <asm/addrspace.h>
  #include <asm/page.h>
  #include <asm/pgtable.h>
  #include <asm/processor.h>
  #include <asm/cache.h>
  #include <asm/io.h>
  #include <asm/uaccess.h>
  #include <asm/pgalloc.h>
  #include <asm/mmu_context.h>
  #include <asm/cacheflush.h>
  
  /*
   * The 32KB cache on the SH7705 suffers from the same synonym problem
   * as SH4 CPUs
   */
  static inline void cache_wback_all(void)
  {
  	unsigned long ways, waysize, addrstart;
  
  	ways = current_cpu_data.dcache.ways;
  	waysize = current_cpu_data.dcache.sets;
  	waysize <<= current_cpu_data.dcache.entry_shift;
  
  	addrstart = CACHE_OC_ADDRESS_ARRAY;
  
  	do {
  		unsigned long addr;
  
  		for (addr = addrstart;
  		     addr < addrstart + waysize;
  		     addr += current_cpu_data.dcache.linesz) {
  			unsigned long data;
  			int v = SH_CACHE_UPDATED | SH_CACHE_VALID;
  
  			data = __raw_readl(addr);
  
  			if ((data & v) == v)
  				__raw_writel(data & ~v, addr);
  
  		}
  
  		addrstart += current_cpu_data.dcache.way_incr;
  	} while (--ways);
  }
  
  /*
   * Write back the range of D-cache, and purge the I-cache.
   *
   * Called from kernel/module.c:sys_init_module and routine for a.out format.
   */
  static void sh7705_flush_icache_range(void *args)
  {
  	struct flusher_data *data = args;
  	unsigned long start, end;
  
  	start = data->addr1;
  	end = data->addr2;
  
  	__flush_wback_region((void *)start, end - start);
  }
  
  /*
   * Writeback&Invalidate the D-cache of the page
   */
  static void __flush_dcache_page(unsigned long phys)
  {
  	unsigned long ways, waysize, addrstart;
  	unsigned long flags;
  
  	phys |= SH_CACHE_VALID;
  
  	/*
  	 * Here, phys is the physical address of the page. We check all the
  	 * tags in the cache for those with the same page number as this page
  	 * (by masking off the lowest 2 bits of the 19-bit tag; these bits are
  	 * derived from the offset within in the 4k page). Matching valid
  	 * entries are invalidated.
  	 *
  	 * Since 2 bits of the cache index are derived from the virtual page
  	 * number, knowing this would reduce the number of cache entries to be
  	 * searched by a factor of 4. However this function exists to deal with
  	 * potential cache aliasing, therefore the optimisation is probably not
  	 * possible.
  	 */
  	local_irq_save(flags);
  	jump_to_uncached();
  
  	ways = current_cpu_data.dcache.ways;
  	waysize = current_cpu_data.dcache.sets;
  	waysize <<= current_cpu_data.dcache.entry_shift;
  
  	addrstart = CACHE_OC_ADDRESS_ARRAY;
  
  	do {
  		unsigned long addr;
  
  		for (addr = addrstart;
  		     addr < addrstart + waysize;
  		     addr += current_cpu_data.dcache.linesz) {
  			unsigned long data;
  
  			data = __raw_readl(addr) & (0x1ffffC00 | SH_CACHE_VALID);
  		        if (data == phys) {
  				data &= ~(SH_CACHE_VALID | SH_CACHE_UPDATED);
  				__raw_writel(data, addr);
  			}
  		}
  
  		addrstart += current_cpu_data.dcache.way_incr;
  	} while (--ways);
  
  	back_to_cached();
  	local_irq_restore(flags);
  }
  
  /*
   * Write back & invalidate the D-cache of the page.
   * (To avoid "alias" issues)
   */
  static void sh7705_flush_dcache_page(void *arg)
  {
  	struct page *page = arg;
  	struct address_space *mapping = page_mapping(page);
  
  	if (mapping && !mapping_mapped(mapping))
  		clear_bit(PG_dcache_clean, &page->flags);
  	else
  		__flush_dcache_page(__pa(page_address(page)));
  }
  
  static void sh7705_flush_cache_all(void *args)
  {
  	unsigned long flags;
  
  	local_irq_save(flags);
  	jump_to_uncached();
  
  	cache_wback_all();
  	back_to_cached();
  	local_irq_restore(flags);
  }
  
  /*
   * Write back and invalidate I/D-caches for the page.
   *
   * ADDRESS: Virtual Address (U0 address)
   */
  static void sh7705_flush_cache_page(void *args)
  {
  	struct flusher_data *data = args;
  	unsigned long pfn = data->addr2;
  
  	__flush_dcache_page(pfn << PAGE_SHIFT);
  }
  
  /*
   * This is called when a page-cache page is about to be mapped into a
   * user process' address space.  It offers an opportunity for a
   * port to ensure d-cache/i-cache coherency if necessary.
   *
   * Not entirely sure why this is necessary on SH3 with 32K cache but
   * without it we get occasional "Memory fault" when loading a program.
   */
  static void sh7705_flush_icache_page(void *page)
  {
  	__flush_purge_region(page_address(page), PAGE_SIZE);
  }
  
  void __init sh7705_cache_init(void)
  {
  	local_flush_icache_range	= sh7705_flush_icache_range;
  	local_flush_dcache_page		= sh7705_flush_dcache_page;
  	local_flush_cache_all		= sh7705_flush_cache_all;
  	local_flush_cache_mm		= sh7705_flush_cache_all;
  	local_flush_cache_dup_mm	= sh7705_flush_cache_all;
  	local_flush_cache_range		= sh7705_flush_cache_all;
  	local_flush_cache_page		= sh7705_flush_cache_page;
  	local_flush_icache_page		= sh7705_flush_icache_page;
  }