1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * This file is subject to the terms and conditions of the GNU General Public
3*4882a593Smuzhiyun * License. See the file "COPYING" in the main directory of this archive
4*4882a593Smuzhiyun * for more details.
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Copyright (C) 2005 Thiemo Seufer
7*4882a593Smuzhiyun * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
8*4882a593Smuzhiyun * Author: Maciej W. Rozycki <macro@mips.com>
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <asm/addrspace.h>
13*4882a593Smuzhiyun #include <asm/bug.h>
14*4882a593Smuzhiyun #include <asm/cacheflush.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun #ifndef CKSEG2
17*4882a593Smuzhiyun #define CKSEG2 CKSSEG
18*4882a593Smuzhiyun #endif
19*4882a593Smuzhiyun #ifndef TO_PHYS_MASK
20*4882a593Smuzhiyun #define TO_PHYS_MASK -1
21*4882a593Smuzhiyun #endif
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun /*
24*4882a593Smuzhiyun * FUNC is executed in one of the uncached segments, depending on its
25*4882a593Smuzhiyun * original address as follows:
26*4882a593Smuzhiyun *
27*4882a593Smuzhiyun * 1. If the original address is in CKSEG0 or CKSEG1, then the uncached
28*4882a593Smuzhiyun * segment used is CKSEG1.
29*4882a593Smuzhiyun * 2. If the original address is in XKPHYS, then the uncached segment
30*4882a593Smuzhiyun * used is XKPHYS(2).
31*4882a593Smuzhiyun * 3. Otherwise it's a bug.
32*4882a593Smuzhiyun *
33*4882a593Smuzhiyun * The same remapping is done with the stack pointer. Stack handling
34*4882a593Smuzhiyun * works because we don't handle stack arguments or more complex return
35*4882a593Smuzhiyun * values, so we can avoid sharing the same stack area between a cached
36*4882a593Smuzhiyun * and the uncached mode.
37*4882a593Smuzhiyun */
run_uncached(void * func)38*4882a593Smuzhiyun unsigned long run_uncached(void *func)
39*4882a593Smuzhiyun {
40*4882a593Smuzhiyun register long ret __asm__("$2");
41*4882a593Smuzhiyun long lfunc = (long)func, ufunc;
42*4882a593Smuzhiyun long usp;
43*4882a593Smuzhiyun long sp;
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun __asm__("move %0, $sp" : "=r" (sp));
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
48*4882a593Smuzhiyun usp = CKSEG1ADDR(sp);
49*4882a593Smuzhiyun #ifdef CONFIG_64BIT
50*4882a593Smuzhiyun else if ((long long)sp >= (long long)PHYS_TO_XKPHYS(0, 0) &&
51*4882a593Smuzhiyun (long long)sp < (long long)PHYS_TO_XKPHYS(8, 0))
52*4882a593Smuzhiyun usp = PHYS_TO_XKPHYS(K_CALG_UNCACHED,
53*4882a593Smuzhiyun XKPHYS_TO_PHYS((long long)sp));
54*4882a593Smuzhiyun #endif
55*4882a593Smuzhiyun else {
56*4882a593Smuzhiyun BUG();
57*4882a593Smuzhiyun usp = sp;
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun if (lfunc >= (long)CKSEG0 && lfunc < (long)CKSEG2)
60*4882a593Smuzhiyun ufunc = CKSEG1ADDR(lfunc);
61*4882a593Smuzhiyun #ifdef CONFIG_64BIT
62*4882a593Smuzhiyun else if ((long long)lfunc >= (long long)PHYS_TO_XKPHYS(0, 0) &&
63*4882a593Smuzhiyun (long long)lfunc < (long long)PHYS_TO_XKPHYS(8, 0))
64*4882a593Smuzhiyun ufunc = PHYS_TO_XKPHYS(K_CALG_UNCACHED,
65*4882a593Smuzhiyun XKPHYS_TO_PHYS((long long)lfunc));
66*4882a593Smuzhiyun #endif
67*4882a593Smuzhiyun else {
68*4882a593Smuzhiyun BUG();
69*4882a593Smuzhiyun ufunc = lfunc;
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun __asm__ __volatile__ (
73*4882a593Smuzhiyun " move $16, $sp\n"
74*4882a593Smuzhiyun " move $sp, %1\n"
75*4882a593Smuzhiyun " jalr %2\n"
76*4882a593Smuzhiyun " move $sp, $16"
77*4882a593Smuzhiyun : "=r" (ret)
78*4882a593Smuzhiyun : "r" (usp), "r" (ufunc)
79*4882a593Smuzhiyun : "$16", "$31");
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun return ret;
82*4882a593Smuzhiyun }
83