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Diffstat (limited to 'include/asm-xtensa/system.h')
| -rw-r--r-- | include/asm-xtensa/system.h | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/include/asm-xtensa/system.h b/include/asm-xtensa/system.h new file mode 100644 index 00000000000..690fe325e67 --- /dev/null +++ b/include/asm-xtensa/system.h @@ -0,0 +1,252 @@ +/* + * include/asm-xtensa/system.h + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + */ + +#ifndef _XTENSA_SYSTEM_H +#define _XTENSA_SYSTEM_H + +#include <linux/config.h> +#include <linux/stringify.h> + +#include <asm/processor.h> + +/* interrupt control */ + +#define local_save_flags(x) \ + __asm__ __volatile__ ("rsr %0,"__stringify(PS) : "=a" (x)); +#define local_irq_restore(x) do { \ + __asm__ __volatile__ ("wsr %0, "__stringify(PS)" ; rsync" \ + :: "a" (x) : "memory"); } while(0); +#define local_irq_save(x) do { \ + __asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL) \ + : "=a" (x) :: "memory");} while(0); + +static inline void local_irq_disable(void) +{ + unsigned long flags; + __asm__ __volatile__ ("rsil %0, "__stringify(LOCKLEVEL) + : "=a" (flags) :: "memory"); +} +static inline void local_irq_enable(void) +{ + unsigned long flags; + __asm__ __volatile__ ("rsil %0, 0" : "=a" (flags) :: "memory"); + +} + +static inline int irqs_disabled(void) +{ + unsigned long flags; + local_save_flags(flags); + return flags & 0xf; +} + +#define RSR_CPENABLE(x) do { \ + __asm__ __volatile__("rsr %0," __stringify(CPENABLE) : "=a" (x)); \ + } while(0); +#define WSR_CPENABLE(x) do { \ + __asm__ __volatile__("wsr %0," __stringify(CPENABLE)";rsync" \ + :: "a" (x));} while(0); + +#define clear_cpenable() __clear_cpenable() + +extern __inline__ void __clear_cpenable(void) +{ +#if XCHAL_HAVE_CP + unsigned long i = 0; + WSR_CPENABLE(i); +#endif +} + +extern __inline__ void enable_coprocessor(int i) +{ +#if XCHAL_HAVE_CP + int cp; + RSR_CPENABLE(cp); + cp |= 1 << i; + WSR_CPENABLE(cp); +#endif +} + +extern __inline__ void disable_coprocessor(int i) +{ +#if XCHAL_HAVE_CP + int cp; + RSR_CPENABLE(cp); + cp &= ~(1 << i); + WSR_CPENABLE(cp); +#endif +} + +#define smp_read_barrier_depends() do { } while(0) +#define read_barrier_depends() do { } while(0) + +#define mb() barrier() +#define rmb() mb() +#define wmb() mb() + +#ifdef CONFIG_SMP +#error smp_* not defined +#else +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#endif + +#define set_mb(var, value) do { var = value; mb(); } while (0) +#define set_wmb(var, value) do { var = value; wmb(); } while (0) + +#if !defined (__ASSEMBLY__) + +/* * switch_to(n) should switch tasks to task nr n, first + * checking that n isn't the current task, in which case it does nothing. + */ +extern void *_switch_to(void *last, void *next); + +#endif /* __ASSEMBLY__ */ + +#define prepare_to_switch() do { } while(0) + +#define switch_to(prev,next,last) \ +do { \ + clear_cpenable(); \ + (last) = _switch_to(prev, next); \ +} while(0) + +/* + * cmpxchg + */ + +extern __inline__ unsigned long +__cmpxchg_u32(volatile int *p, int old, int new) +{ + __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t" + "l32i %0, %1, 0 \n\t" + "bne %0, %2, 1f \n\t" + "s32i %3, %1, 0 \n\t" + "1: \n\t" + "wsr a15, "__stringify(PS)" \n\t" + "rsync \n\t" + : "=&a" (old) + : "a" (p), "a" (old), "r" (new) + : "a15", "memory"); + return old; +} +/* This function doesn't exist, so you'll get a linker error + * if something tries to do an invalid cmpxchg(). */ + +extern void __cmpxchg_called_with_bad_pointer(void); + +static __inline__ unsigned long +__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) +{ + switch (size) { + case 4: return __cmpxchg_u32(ptr, old, new); + default: __cmpxchg_called_with_bad_pointer(); + return old; + } +} + +#define cmpxchg(ptr,o,n) \ + ({ __typeof__(*(ptr)) _o_ = (o); \ + __typeof__(*(ptr)) _n_ = (n); \ + (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ + (unsigned long)_n_, sizeof (*(ptr))); \ + }) + + + + +/* + * xchg_u32 + * + * Note that a15 is used here because the register allocation + * done by the compiler is not guaranteed and a window overflow + * may not occur between the rsil and wsr instructions. By using + * a15 in the rsil, the machine is guaranteed to be in a state + * where no register reference will cause an overflow. + */ + +extern __inline__ unsigned long xchg_u32(volatile int * m, unsigned long val) +{ + unsigned long tmp; + __asm__ __volatile__("rsil a15, "__stringify(LOCKLEVEL)"\n\t" + "l32i %0, %1, 0 \n\t" + "s32i %2, %1, 0 \n\t" + "wsr a15, "__stringify(PS)" \n\t" + "rsync \n\t" + : "=&a" (tmp) + : "a" (m), "a" (val) + : "a15", "memory"); + return tmp; +} + +#define tas(ptr) (xchg((ptr),1)) + +#if ( __XCC__ == 1 ) + +/* xt-xcc processes __inline__ differently than xt-gcc and decides to + * insert an out-of-line copy of function __xchg. This presents the + * unresolved symbol at link time of __xchg_called_with_bad_pointer, + * even though such a function would never be called at run-time. + * xt-gcc always inlines __xchg, and optimizes away the undefined + * bad_pointer function. + */ + +#define xchg(ptr,x) xchg_u32(ptr,x) + +#else /* assume xt-gcc */ + +#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) + +/* + * This only works if the compiler isn't horribly bad at optimizing. + * gcc-2.5.8 reportedly can't handle this, but I define that one to + * be dead anyway. + */ + +extern void __xchg_called_with_bad_pointer(void); + +static __inline__ unsigned long +__xchg(unsigned long x, volatile void * ptr, int size) +{ + switch (size) { + case 4: + return xchg_u32(ptr, x); + } + __xchg_called_with_bad_pointer(); + return x; +} + +#endif + +extern void set_except_vector(int n, void *addr); + +static inline void spill_registers(void) +{ + unsigned int a0, ps; + + __asm__ __volatile__ ( + "movi a14," __stringify (PS_EXCM_MASK) " | 1\n\t" + "mov a12, a0\n\t" + "rsr a13," __stringify(SAR) "\n\t" + "xsr a14," __stringify(PS) "\n\t" + "movi a0, _spill_registers\n\t" + "rsync\n\t" + "callx0 a0\n\t" + "mov a0, a12\n\t" + "wsr a13," __stringify(SAR) "\n\t" + "wsr a14," __stringify(PS) "\n\t" + :: "a" (&a0), "a" (&ps) + : "a2", "a3", "a12", "a13", "a14", "a15", "memory"); +} + +#define arch_align_stack(x) (x) + +#endif /* _XTENSA_SYSTEM_H */ |