/* * 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/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() static inline void __clear_cpenable(void) { #if XCHAL_HAVE_CP unsigned long i = 0; WSR_CPENABLE(i); #endif } static inline void enable_coprocessor(int i) { #if XCHAL_HAVE_CP int cp; RSR_CPENABLE(cp); cp |= 1 << i; WSR_CPENABLE(cp); #endif } static 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) #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 switch_to(prev,next,last) \ do { \ clear_cpenable(); \ (last) = _switch_to(prev, next); \ } while(0) /* * cmpxchg */ static 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. */ static 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)) #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; } 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_BIT) " | 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 */