| Thiemo Seufer | ba5187d | 2005-04-25 16:36:23 +0000 | [diff] [blame] | 1 | /* |
| 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 Nemoto | 8c41286 | 2007-07-12 00:55:40 +0900 | [diff] [blame] | 15 | #include <asm/cacheflush.h> |
| Thiemo Seufer | ba5187d | 2005-04-25 16:36:23 +0000 | [diff] [blame] | 16 | |
| 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 | */ |
| 39 | unsigned 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 Yuasa | c55197e | 2007-02-06 10:59:22 +0900 | [diff] [blame] | 48 | #ifdef CONFIG_64BIT |
| Thiemo Seufer | ba5187d | 2005-04-25 16:36:23 +0000 | [diff] [blame] | 49 | 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 Yuasa | c55197e | 2007-02-06 10:59:22 +0900 | [diff] [blame] | 53 | #endif |
| Thiemo Seufer | ba5187d | 2005-04-25 16:36:23 +0000 | [diff] [blame] | 54 | else { |
| 55 | BUG(); |
| 56 | usp = sp; |
| 57 | } |
| 58 | if (lfunc >= (long)CKSEG0 && lfunc < (long)CKSEG2) |
| 59 | ufunc = CKSEG1ADDR(lfunc); |
| Yoichi Yuasa | c55197e | 2007-02-06 10:59:22 +0900 | [diff] [blame] | 60 | #ifdef CONFIG_64BIT |
| Thiemo Seufer | ba5187d | 2005-04-25 16:36:23 +0000 | [diff] [blame] | 61 | 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 Yuasa | c55197e | 2007-02-06 10:59:22 +0900 | [diff] [blame] | 65 | #endif |
| Thiemo Seufer | ba5187d | 2005-04-25 16:36:23 +0000 | [diff] [blame] | 66 | 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 | } |