#ifndef _ASM_M32R_SYSTEM_H
#define _ASM_M32R_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 by Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
* Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
*/
#include <linux/config.h>
#include <asm/assembler.h>
#ifdef __KERNEL__
/*
* switch_to(prev, next) should switch from task `prev' to `next'
* `prev' will never be the same as `next'.
*
* `next' and `prev' should be struct task_struct, but it isn't always defined
*/
#ifndef CONFIG_SMP
#define prepare_to_switch() do { } while(0)
#endif /* not CONFIG_SMP */
#define switch_to(prev, next, last) do { \
register unsigned long arg0 __asm__ ("r0") = (unsigned long)prev; \
register unsigned long arg1 __asm__ ("r1") = (unsigned long)next; \
register unsigned long *oldsp __asm__ ("r2") = &(prev->thread.sp); \
register unsigned long *newsp __asm__ ("r3") = &(next->thread.sp); \
register unsigned long *oldlr __asm__ ("r4") = &(prev->thread.lr); \
register unsigned long *newlr __asm__ ("r5") = &(next->thread.lr); \
register struct task_struct *__last __asm__ ("r6"); \
__asm__ __volatile__ ( \
"st r8, @-r15 \n\t" \
"st r9, @-r15 \n\t" \
"st r10, @-r15 \n\t" \
"st r11, @-r15 \n\t" \
"st r12, @-r15 \n\t" \
"st r13, @-r15 \n\t" \
"st r14, @-r15 \n\t" \
"seth r14, #high(1f) \n\t" \
"or3 r14, r14, #low(1f) \n\t" \
"st r14, @r4 ; store old LR \n\t" \
"st r15, @r2 ; store old SP \n\t" \
"ld r15, @r3 ; load new SP \n\t" \
"st r0, @-r15 ; store 'prev' onto new stack \n\t" \
"ld r14, @r5 ; load new LR \n\t" \
"jmp r14 \n\t" \
".fillinsn \n " \
"1: \n\t" \
"ld r6, @r15+ ; load 'prev' from new stack \n\t" \
"ld r14, @r15+ \n\t" \
"ld r13, @r15+ \n\t" \
"ld r12, @r15+ \n\t" \
"ld r11, @r15+ \n\t" \
"ld r10, @r15+ \n\t" \
"ld r9, @r15+ \n\t" \
"ld r8, @r15+ \n\t" \
: "=&r" (__last) \
: "r" (arg0), "r" (arg1), "r" (oldsp), "r" (newsp), \
"r" (oldlr), "r" (newlr) \
: "memory" \
); \
last = __last; \
} while(0)
/*
* On SMP systems, when the scheduler does migration-cost autodetection,
* it needs a way to flush as much of the CPU's caches as possible.
*
* TODO: fill this in!
*/
static inline void sched_cacheflush(void)
{
}
/* Interrupt Control */
#if !defined(CONFIG_CHIP_M32102) && !defined(CONFIG_CHIP_M32104)
#define local_irq_enable() \
__asm__ __volatile__ ("setpsw #0x40 -> nop": : :"memory")
#define local_irq_disable() \
__asm__ __volatile__ ("clrpsw #0x40 -> nop": : :"memory")
#else /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
static inline void local_irq_enable(void)
{
unsigned long tmpreg;
__asm__ __volatile__(
"mvfc %0, psw; \n\t"
"or3 %0, %0, #0x0040; \n\t"
"mvtc %0, psw; \n\t"
: "=&r" (tmpreg) : : "cbit", "memory");
}
static inline void local_irq_disable(void)
{
unsigned long tmpreg0, tmpreg1;
__asm__ __volatile__(
"ld24 %0, #0 ; Use 32-bit insn. \n\t"
"mvfc %1, psw ; No interrupt can be accepted here. \n\t"
"mvtc %0, psw \n\t"
"and3 %0, %1, #0xffbf \n\t"
"mvtc %0, psw \n\t"
: "=&r" (tmpreg0), "=&r" (tmpreg1) : : "cbit", "memory");
}
#endif /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
#define local_save_flags(x) \
__asm__ __volatile__("mvfc %0,psw" : "=r"(x) : /* no input */)
#define local_irq_restore(x) \
__asm__ __volatile__("mvtc %0,psw" : /* no outputs */ \
: "r" (x) : "cbit", "memory")
#if !(defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_M32104))
#define local_irq_save(x) \
__asm__ __volatile__( \
"mvfc %0, psw; \n\t" \
"clrpsw #0x40 -> nop; \n\t" \
: "=r" (x) : /* no input */ : "memory")
#else /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
#define local_irq_save(x) \
({ \
unsigned long tmpreg; \
__asm__ __volatile__( \
"ld24 %1, #0 \n\t" \
"mvfc %0, psw \n\t" \
"mvtc %1, psw \n\t" \
"and3 %1, %0, #0xffbf \n\t" \
"mvtc %1, psw \n\t" \
: "=r" (x), "=&r" (tmpreg) \
: : "cbit", "memory"); \
})
#endif /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
#define irqs_disabled() \
({ \
unsigned long flags; \
local_save_flags(flags); \
!(flags & 0x40); \
})
#define nop() __asm__ __volatile__ ("nop" : : )
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))
#ifdef CONFIG_SMP
extern void __xchg_called_with_bad_pointer(void);
#endif
#ifdef CONFIG_CHIP_M32700_TS1
#define DCACHE_CLEAR(reg0, reg1, addr) \
"seth "reg1", #high(dcache_dummy); \n\t" \
"or3 "reg1", "reg1", #low(dcache_dummy); \n\t" \
"lock "reg0", @"reg1"; \n\t" \
"add3 "reg0", "addr", #0x1000; \n\t" \
"ld "reg0", @"reg0"; \n\t" \
"add3 "reg0", "addr", #0x2000; \n\t" \
"ld "reg0", @"reg0"; \n\t" \
"unlock "reg0", @"reg1"; \n\t"
/* FIXME: This workaround code cannot handle kenrel modules
* correctly under SMP environment.
*/
#else /* CONFIG_CHIP_M32700_TS1 */
#define DCACHE_CLEAR(reg0, reg1, addr)
#endif /* CONFIG_CHIP_M32700_TS1 */
static __inline__ unsigned long __xchg(unsigned long x, volatile void * ptr,
int size)
{
unsigned long flags;
unsigned long tmp = 0;
local_irq_save(flags);
switch (size) {
#ifndef CONFIG_SMP
case 1:
__asm__ __volatile__ (
"ldb %0, @%2 \n\t"
"stb %1, @%2 \n\t"
: "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
break;
case 2:
__asm__ __volatile__ (
"ldh %0, @%2 \n\t"
"sth %1, @%2 \n\t"
: "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
break;
case 4:
__asm__ __volatile__ (
"ld %0, @%2 \n\t"
"st %1, @%2 \n\t"
: "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
break;
#else /* CONFIG_SMP */
case 4:
__asm__ __volatile__ (
DCACHE_CLEAR("%0", "r4", "%2")
"lock %0, @%2; \n\t"
"unlock %1, @%2; \n\t"
: "=&r" (tmp) : "r" (x), "r" (ptr)
: "memory"
#ifdef CONFIG_CHIP_M32700_TS1
, "r4"
#endif /* CONFIG_CHIP_M32700_TS1 */
);
break;
default:
__xchg_called_with_bad_pointer();
#endif /* CONFIG_SMP */
}
local_irq_restore(flags);
return (tmp);
}
#define __HAVE_ARCH_CMPXCHG 1
static __inline__ unsigned long
__cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
{
unsigned long flags;
unsigned int retval;
local_irq_save(flags);
__asm__ __volatile__ (
DCACHE_CLEAR("%0", "r4", "%1")
M32R_LOCK" %0, @%1; \n"
" bne %0, %2, 1f; \n"
M32R_UNLOCK" %3, @%1; \n"
" bra 2f; \n"
" .fillinsn \n"
"1:"
M32R_UNLOCK" %0, @%1; \n"
" .fillinsn \n"
"2:"
: "=&r" (retval)
: "r" (p), "r" (old), "r" (new)
: "cbit", "memory"
#ifdef CONFIG_CHIP_M32700_TS1
, "r4"
#endif /* CONFIG_CHIP_M32700_TS1 */
);
local_irq_restore(flags);
return retval;
}
/* 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);
#if 0 /* we don't have __cmpxchg_u64 */
case 8:
return __cmpxchg_u64(ptr, old, new);
#endif /* 0 */
}
__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))); \
})
#endif /* __KERNEL__ */
/*
* Memory barrier.
*
* mb() prevents loads and stores being reordered across this point.
* rmb() prevents loads being reordered across this point.
* wmb() prevents stores being reordered across this point.
*/
#define mb() barrier()
#define rmb() mb()
#define wmb() mb()
/**
* read_barrier_depends - Flush all pending reads that subsequents reads
* depend on.
*
* No data-dependent reads from memory-like regions are ever reordered
* over this barrier. All reads preceding this primitive are guaranteed
* to access memory (but not necessarily other CPUs' caches) before any
* reads following this primitive that depend on the data return by
* any of the preceding reads. This primitive is much lighter weight than
* rmb() on most CPUs, and is never heavier weight than is
* rmb().
*
* These ordering constraints are respected by both the local CPU
* and the compiler.
*
* Ordering is not guaranteed by anything other than these primitives,
* not even by data dependencies. See the documentation for
* memory_barrier() for examples and URLs to more information.
*
* For example, the following code would force ordering (the initial
* value of "a" is zero, "b" is one, and "p" is "&a"):
*
* <programlisting>
* CPU 0 CPU 1
*
* b = 2;
* memory_barrier();
* p = &b; q = p;
* read_barrier_depends();
* d = *q;
* </programlisting>
*
*
* because the read of "*q" depends on the read of "p" and these
* two reads are separated by a read_barrier_depends(). However,
* the following code, with the same initial values for "a" and "b":
*
* <programlisting>
* CPU 0 CPU 1
*
* a = 2;
* memory_barrier();
* b = 3; y = b;
* read_barrier_depends();
* x = a;
* </programlisting>
*
* does not enforce ordering, since there is no data dependency between
* the read of "a" and the read of "b". Therefore, on some CPUs, such
* as Alpha, "y" could be set to 3 and "x" to 0. Use rmb()
* in cases like thiswhere there are no data dependencies.
**/
#define read_barrier_depends() do { } while (0)
#ifdef CONFIG_SMP
#define smp_mb() mb()
#define smp_rmb() rmb()
#define smp_wmb() wmb()
#define smp_read_barrier_depends() read_barrier_depends()
#else
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#define smp_read_barrier_depends() do { } while (0)
#endif
#define set_mb(var, value) do { xchg(&var, value); } while (0)
#define set_wmb(var, value) do { var = value; wmb(); } while (0)
#define arch_align_stack(x) (x)
#endif /* _ASM_M32R_SYSTEM_H */
