xref: /openbmc/linux/arch/sh/mm/uncached.c (revision bc5aa3a0)
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 }
44