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