- 根目录:
- arch
- m32r
- include
- asm
- system.h
#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 Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
* Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
*/
#include <linux/compiler.h>
#include <linux/irqflags.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
*/
#if defined(CONFIG_FRAME_POINTER) || \
!defined(CONFIG_SCHED_OMIT_FRAME_POINTER)
#define M32R_PUSH_FP " push fp\n"
#define M32R_POP_FP " pop fp\n"
#else
#define M32R_PUSH_FP ""
#define M32R_POP_FP ""
#endif
#define switch_to(prev, next, last) do { \
__asm__ __volatile__ ( \
" seth lr, #high(1f) \n" \
" or3 lr, lr, #low(1f) \n" \
" st lr, @%4 ; store old LR \n" \
" ld lr, @%5 ; load new LR \n" \
M32R_PUSH_FP \
" st sp, @%2 ; store old SP \n" \
" ld sp, @%3 ; load new SP \n" \
" push %1 ; store `prev' on new stack \n" \
" jmp lr \n" \
" .fillinsn \n" \
"1: \n" \
" pop %0 ; restore `__last' from new stack \n" \
M32R_POP_FP \
: "=r" (last) \
: "0" (prev), \
"r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \
"r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \
: "memory", "lr" \
); \
} while(0)
#define nop() __asm__ __volatile__ ("nop" : : )
#define xchg(ptr, x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
#define xchg_local(ptr, x) \
((__typeof__(*(ptr)))__xchg_local((unsigned long)(x), (ptr), \
sizeof(*(ptr))))
extern void __xchg_called_with_bad_pointer(void);
#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 kernel modules
* correctly under SMP environment.
*/
#else /* CONFIG_CHIP_M32700_TS1 */
#define DCACHE_CLEAR(reg0, reg1, addr)
#endif /* CONFIG_CHIP_M32700_TS1 */
static __always_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;
#endif /* CONFIG_SMP */
default:
__xchg_called_with_bad_pointer();
}
local_irq_restore(flags);
return (tmp);
}
static __always_inline unsigned long
__xchg_local(unsigned long x, volatile void *ptr, int size)
{
unsigned long flags;
unsigned long tmp = 0;
local_irq_save(flags);
switch (size) {
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;
default:
__xchg_called_with_bad_pointer();
}
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;
}
static inline unsigned long
__cmpxchg_local_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")
"ld %0, @%1; \n"
" bne %0, %2, 1f; \n"
"st %3, @%1; \n"
" bra 2f; \n"
" .fillinsn \n"
"1:"
"st %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))) __cmpxchg((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
#include <asm-generic/cmpxchg-local.h>
static inline unsigned long __cmpxchg_local(volatile void *ptr,
unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 4:
return __cmpxchg_local_u32(ptr, old, new);
default:
return __cmpxchg_local_generic(ptr, old, new, size);
}
return old;
}
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#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 this where 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()
#define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
#else
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#define smp_read_barrier_depends() do { } while (0)
#define set_mb(var, value) do { var = value; barrier(); } while (0)
#endif
#define arch_align_stack(x) (x)
#endif /* _ASM_M32R_SYSTEM_H */