arch/sh/mm/uncached.c

   1 #include <linux/init.h>
   2 #include <linux/module.h>
   3 #include <asm/sizes.h>
   4 #include <asm/page.h>
   5 #include <asm/addrspace.h>
   6
   7 /*
   8  * This is the offset of the uncached section from its cached alias.
   9  *
  10  * Legacy platforms handle trivial transitions between cached and
  11  * uncached segments by making use of the 1:1 mapping relationship in
  12  * 512MB lowmem, others via a special uncached mapping.
  13  *
  14  * Default value only valid in 29 bit mode, in 32bit mode this will be
  15  * updated by the early PMB initialization code.
  16  */
  17 unsigned long cached_to_uncached = SZ_512M;
  18 unsigned long uncached_size = SZ_512M;
  19 unsigned long uncached_start, uncached_end;
  20 EXPORT_SYMBOL(uncached_start);
  21 EXPORT_SYMBOL(uncached_end);
  22
  23 int virt_addr_uncached(unsigned long kaddr)
  24 {
  25         return (kaddr >= uncached_start) && (kaddr < uncached_end);
  26 }
  27 EXPORT_SYMBOL(virt_addr_uncached);
  28
  29 void __init uncached_init(void)
  30 {
  31 #if defined(CONFIG_29BIT) || !defined(CONFIG_MMU)
  32         uncached_start = P2SEG;
  33 #else
  34         uncached_start = memory_end;
  35 #endif
  36         uncached_end = uncached_start + uncached_size;
  37 }
  38
  39 void __init uncached_resize(unsigned long size)
  40 {
  41         uncached_size = size;
  42         uncached_end = uncached_start + uncached_size;
  43 }