Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 1 | /* |
| 2 | * include/asm-xtensa/system.h |
| 3 | * |
| 4 | * This file is subject to the terms and conditions of the GNU General Public |
| 5 | * License. See the file "COPYING" in the main directory of this archive |
| 6 | * for more details. |
| 7 | * |
| 8 | * Copyright (C) 2001 - 2005 Tensilica Inc. |
| 9 | */ |
| 10 | |
| 11 | #ifndef _XTENSA_SYSTEM_H |
| 12 | #define _XTENSA_SYSTEM_H |
| 13 | |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 14 | #include <linux/stringify.h> |
David Howells | df9ee29 | 2010-10-07 14:08:55 +0100 | [diff] [blame] | 15 | #include <linux/irqflags.h> |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 16 | |
| 17 | #include <asm/processor.h> |
| 18 | |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 19 | #define smp_read_barrier_depends() do { } while(0) |
| 20 | #define read_barrier_depends() do { } while(0) |
| 21 | |
| 22 | #define mb() barrier() |
| 23 | #define rmb() mb() |
| 24 | #define wmb() mb() |
| 25 | |
| 26 | #ifdef CONFIG_SMP |
| 27 | #error smp_* not defined |
| 28 | #else |
| 29 | #define smp_mb() barrier() |
| 30 | #define smp_rmb() barrier() |
| 31 | #define smp_wmb() barrier() |
| 32 | #endif |
| 33 | |
| 34 | #define set_mb(var, value) do { var = value; mb(); } while (0) |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 35 | |
| 36 | #if !defined (__ASSEMBLY__) |
| 37 | |
| 38 | /* * switch_to(n) should switch tasks to task nr n, first |
| 39 | * checking that n isn't the current task, in which case it does nothing. |
| 40 | */ |
| 41 | extern void *_switch_to(void *last, void *next); |
| 42 | |
| 43 | #endif /* __ASSEMBLY__ */ |
| 44 | |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 45 | #define switch_to(prev,next,last) \ |
| 46 | do { \ |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 47 | (last) = _switch_to(prev, next); \ |
| 48 | } while(0) |
| 49 | |
| 50 | /* |
| 51 | * cmpxchg |
| 52 | */ |
| 53 | |
Adrian Bunk | d99cf71 | 2005-09-03 15:57:53 -0700 | [diff] [blame] | 54 | static inline unsigned long |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 55 | __cmpxchg_u32(volatile int *p, int old, int new) |
| 56 | { |
| 57 | __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t" |
| 58 | "l32i %0, %1, 0 \n\t" |
| 59 | "bne %0, %2, 1f \n\t" |
| 60 | "s32i %3, %1, 0 \n\t" |
| 61 | "1: \n\t" |
| 62 | "wsr a15, "__stringify(PS)" \n\t" |
| 63 | "rsync \n\t" |
| 64 | : "=&a" (old) |
| 65 | : "a" (p), "a" (old), "r" (new) |
| 66 | : "a15", "memory"); |
| 67 | return old; |
| 68 | } |
| 69 | /* This function doesn't exist, so you'll get a linker error |
| 70 | * if something tries to do an invalid cmpxchg(). */ |
| 71 | |
| 72 | extern void __cmpxchg_called_with_bad_pointer(void); |
| 73 | |
| 74 | static __inline__ unsigned long |
| 75 | __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) |
| 76 | { |
| 77 | switch (size) { |
| 78 | case 4: return __cmpxchg_u32(ptr, old, new); |
| 79 | default: __cmpxchg_called_with_bad_pointer(); |
| 80 | return old; |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | #define cmpxchg(ptr,o,n) \ |
| 85 | ({ __typeof__(*(ptr)) _o_ = (o); \ |
| 86 | __typeof__(*(ptr)) _n_ = (n); \ |
| 87 | (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ |
| 88 | (unsigned long)_n_, sizeof (*(ptr))); \ |
| 89 | }) |
| 90 | |
Mathieu Desnoyers | 9a7744f | 2008-02-07 00:16:26 -0800 | [diff] [blame] | 91 | #include <asm-generic/cmpxchg-local.h> |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 92 | |
Mathieu Desnoyers | 9a7744f | 2008-02-07 00:16:26 -0800 | [diff] [blame] | 93 | static inline unsigned long __cmpxchg_local(volatile void *ptr, |
| 94 | unsigned long old, |
| 95 | unsigned long new, int size) |
| 96 | { |
| 97 | switch (size) { |
| 98 | case 4: |
| 99 | return __cmpxchg_u32(ptr, old, new); |
| 100 | default: |
| 101 | return __cmpxchg_local_generic(ptr, old, new, size); |
| 102 | } |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 103 | |
Mathieu Desnoyers | 9a7744f | 2008-02-07 00:16:26 -0800 | [diff] [blame] | 104 | return old; |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make |
| 109 | * them available. |
| 110 | */ |
| 111 | #define cmpxchg_local(ptr, o, n) \ |
| 112 | ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ |
| 113 | (unsigned long)(n), sizeof(*(ptr)))) |
| 114 | #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 115 | |
| 116 | /* |
| 117 | * xchg_u32 |
| 118 | * |
| 119 | * Note that a15 is used here because the register allocation |
| 120 | * done by the compiler is not guaranteed and a window overflow |
| 121 | * may not occur between the rsil and wsr instructions. By using |
| 122 | * a15 in the rsil, the machine is guaranteed to be in a state |
| 123 | * where no register reference will cause an overflow. |
| 124 | */ |
| 125 | |
Adrian Bunk | d99cf71 | 2005-09-03 15:57:53 -0700 | [diff] [blame] | 126 | static inline unsigned long xchg_u32(volatile int * m, unsigned long val) |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 127 | { |
| 128 | unsigned long tmp; |
| 129 | __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t" |
| 130 | "l32i %0, %1, 0 \n\t" |
| 131 | "s32i %2, %1, 0 \n\t" |
| 132 | "wsr a15, "__stringify(PS)" \n\t" |
| 133 | "rsync \n\t" |
| 134 | : "=&a" (tmp) |
| 135 | : "a" (m), "a" (val) |
| 136 | : "a15", "memory"); |
| 137 | return tmp; |
| 138 | } |
| 139 | |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 140 | #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) |
| 141 | |
| 142 | /* |
| 143 | * This only works if the compiler isn't horribly bad at optimizing. |
| 144 | * gcc-2.5.8 reportedly can't handle this, but I define that one to |
| 145 | * be dead anyway. |
| 146 | */ |
| 147 | |
| 148 | extern void __xchg_called_with_bad_pointer(void); |
| 149 | |
| 150 | static __inline__ unsigned long |
| 151 | __xchg(unsigned long x, volatile void * ptr, int size) |
| 152 | { |
| 153 | switch (size) { |
| 154 | case 4: |
| 155 | return xchg_u32(ptr, x); |
| 156 | } |
| 157 | __xchg_called_with_bad_pointer(); |
| 158 | return x; |
| 159 | } |
| 160 | |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 161 | extern void set_except_vector(int n, void *addr); |
| 162 | |
| 163 | static inline void spill_registers(void) |
| 164 | { |
| 165 | unsigned int a0, ps; |
| 166 | |
| 167 | __asm__ __volatile__ ( |
Chris Zankel | 173d668 | 2006-12-10 02:18:48 -0800 | [diff] [blame] | 168 | "movi a14," __stringify (PS_EXCM_BIT) " | 1\n\t" |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 169 | "mov a12, a0\n\t" |
| 170 | "rsr a13," __stringify(SAR) "\n\t" |
| 171 | "xsr a14," __stringify(PS) "\n\t" |
| 172 | "movi a0, _spill_registers\n\t" |
| 173 | "rsync\n\t" |
| 174 | "callx0 a0\n\t" |
| 175 | "mov a0, a12\n\t" |
| 176 | "wsr a13," __stringify(SAR) "\n\t" |
| 177 | "wsr a14," __stringify(PS) "\n\t" |
| 178 | :: "a" (&a0), "a" (&ps) |
Chris Zankel | c658eac | 2008-02-12 13:17:07 -0800 | [diff] [blame] | 179 | : "a2", "a3", "a4", "a7", "a11", "a12", "a13", "a14", "a15", "memory"); |
Chris Zankel | 9a8fd55 | 2005-06-23 22:01:26 -0700 | [diff] [blame] | 180 | } |
| 181 | |
| 182 | #define arch_align_stack(x) (x) |
| 183 | |
| 184 | #endif /* _XTENSA_SYSTEM_H */ |