blob: 58d14f4d9349c3f8b9890c56551c02f8f35737d4 [file] [log] [blame]
Thiemo Seuferba5187d2005-04-25 16:36:23 +00001/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2005 Thiemo Seufer
7 * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
8 * Author: Maciej W. Rozycki <macro@mips.com>
9 */
10
11#include <linux/init.h>
12
13#include <asm/addrspace.h>
14#include <asm/bug.h>
Atsushi Nemoto8c412862007-07-12 00:55:40 +090015#include <asm/cacheflush.h>
Thiemo Seuferba5187d2005-04-25 16:36:23 +000016
17#ifndef CKSEG2
18#define CKSEG2 CKSSEG
19#endif
20#ifndef TO_PHYS_MASK
21#define TO_PHYS_MASK -1
22#endif
23
24/*
25 * FUNC is executed in one of the uncached segments, depending on its
26 * original address as follows:
27 *
28 * 1. If the original address is in CKSEG0 or CKSEG1, then the uncached
29 * segment used is CKSEG1.
30 * 2. If the original address is in XKPHYS, then the uncached segment
31 * used is XKPHYS(2).
32 * 3. Otherwise it's a bug.
33 *
34 * The same remapping is done with the stack pointer. Stack handling
35 * works because we don't handle stack arguments or more complex return
36 * values, so we can avoid sharing the same stack area between a cached
37 * and the uncached mode.
38 */
39unsigned long __init run_uncached(void *func)
40{
41 register long sp __asm__("$sp");
42 register long ret __asm__("$2");
43 long lfunc = (long)func, ufunc;
44 long usp;
45
46 if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
47 usp = CKSEG1ADDR(sp);
Yoichi Yuasac55197e2007-02-06 10:59:22 +090048#ifdef CONFIG_64BIT
Thiemo Seuferba5187d2005-04-25 16:36:23 +000049 else if ((long long)sp >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&
50 (long long)sp < (long long)PHYS_TO_XKPHYS(8LL, 0))
51 usp = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,
52 XKPHYS_TO_PHYS((long long)sp));
Yoichi Yuasac55197e2007-02-06 10:59:22 +090053#endif
Thiemo Seuferba5187d2005-04-25 16:36:23 +000054 else {
55 BUG();
56 usp = sp;
57 }
58 if (lfunc >= (long)CKSEG0 && lfunc < (long)CKSEG2)
59 ufunc = CKSEG1ADDR(lfunc);
Yoichi Yuasac55197e2007-02-06 10:59:22 +090060#ifdef CONFIG_64BIT
Thiemo Seuferba5187d2005-04-25 16:36:23 +000061 else if ((long long)lfunc >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&
62 (long long)lfunc < (long long)PHYS_TO_XKPHYS(8LL, 0))
63 ufunc = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,
64 XKPHYS_TO_PHYS((long long)lfunc));
Yoichi Yuasac55197e2007-02-06 10:59:22 +090065#endif
Thiemo Seuferba5187d2005-04-25 16:36:23 +000066 else {
67 BUG();
68 ufunc = lfunc;
69 }
70
71 __asm__ __volatile__ (
72 " move $16, $sp\n"
73 " move $sp, %1\n"
74 " jalr %2\n"
75 " move $sp, $16"
76 : "=r" (ret)
77 : "r" (usp), "r" (ufunc)
78 : "$16", "$31");
79
80 return ret;
81}