linux/include/asm-sh/system.h
Paul Mundt f151749440 sh: Cleanup and document register bank usage.
Initial register bank cleanup. Make SR.RB configurable, and add some
preliminary documentation on register bank usage within the kernel.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-09-27 16:01:12 +09:00

360 lines
8.7 KiB
C

#ifndef __ASM_SH_SYSTEM_H
#define __ASM_SH_SYSTEM_H
/*
* Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
* Copyright (C) 2002 Paul Mundt
*/
#include <asm/types.h>
/*
* switch_to() should switch tasks to task nr n, first
*/
#define switch_to(prev, next, last) do { \
struct task_struct *__last; \
register unsigned long *__ts1 __asm__ ("r1") = &prev->thread.sp; \
register unsigned long *__ts2 __asm__ ("r2") = &prev->thread.pc; \
register unsigned long *__ts4 __asm__ ("r4") = (unsigned long *)prev; \
register unsigned long *__ts5 __asm__ ("r5") = (unsigned long *)next; \
register unsigned long *__ts6 __asm__ ("r6") = &next->thread.sp; \
register unsigned long __ts7 __asm__ ("r7") = next->thread.pc; \
__asm__ __volatile__ (".balign 4\n\t" \
"stc.l gbr, @-r15\n\t" \
"sts.l pr, @-r15\n\t" \
"mov.l r8, @-r15\n\t" \
"mov.l r9, @-r15\n\t" \
"mov.l r10, @-r15\n\t" \
"mov.l r11, @-r15\n\t" \
"mov.l r12, @-r15\n\t" \
"mov.l r13, @-r15\n\t" \
"mov.l r14, @-r15\n\t" \
"mov.l r15, @r1 ! save SP\n\t" \
"mov.l @r6, r15 ! change to new stack\n\t" \
"mova 1f, %0\n\t" \
"mov.l %0, @r2 ! save PC\n\t" \
"mov.l 2f, %0\n\t" \
"jmp @%0 ! call __switch_to\n\t" \
" lds r7, pr ! with return to new PC\n\t" \
".balign 4\n" \
"2:\n\t" \
".long __switch_to\n" \
"1:\n\t" \
"mov.l @r15+, r14\n\t" \
"mov.l @r15+, r13\n\t" \
"mov.l @r15+, r12\n\t" \
"mov.l @r15+, r11\n\t" \
"mov.l @r15+, r10\n\t" \
"mov.l @r15+, r9\n\t" \
"mov.l @r15+, r8\n\t" \
"lds.l @r15+, pr\n\t" \
"ldc.l @r15+, gbr\n\t" \
: "=z" (__last) \
: "r" (__ts1), "r" (__ts2), "r" (__ts4), \
"r" (__ts5), "r" (__ts6), "r" (__ts7) \
: "r3", "t"); \
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)
{
}
#ifdef CONFIG_CPU_SH4A
#define __icbi() \
{ \
unsigned long __addr; \
__addr = 0xa8000000; \
__asm__ __volatile__( \
"icbi %0\n\t" \
: /* no output */ \
: "m" (__m(__addr))); \
}
#endif
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
static __inline__ unsigned long tas(volatile int *m)
{ /* #define tas(ptr) (xchg((ptr),1)) */
unsigned long retval;
__asm__ __volatile__ ("tas.b @%1\n\t"
"movt %0"
: "=r" (retval): "r" (m): "t", "memory");
return retval;
}
extern void __xchg_called_with_bad_pointer(void);
/*
* A brief note on ctrl_barrier(), the control register write barrier.
*
* Legacy SH cores typically require a sequence of 8 nops after
* modification of a control register in order for the changes to take
* effect. On newer cores (like the sh4a and sh5) this is accomplished
* with icbi.
*
* Also note that on sh4a in the icbi case we can forego a synco for the
* write barrier, as it's not necessary for control registers.
*
* Historically we have only done this type of barrier for the MMUCR, but
* it's also necessary for the CCR, so we make it generic here instead.
*/
#ifdef CONFIG_CPU_SH4A
#define mb() __asm__ __volatile__ ("synco": : :"memory")
#define rmb() mb()
#define wmb() __asm__ __volatile__ ("synco": : :"memory")
#define ctrl_barrier() __icbi()
#define read_barrier_depends() do { } while(0)
#else
#define mb() __asm__ __volatile__ ("": : :"memory")
#define rmb() mb()
#define wmb() __asm__ __volatile__ ("": : :"memory")
#define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
#define read_barrier_depends() do { } while(0)
#endif
#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)
/* Interrupt Control */
#ifdef CONFIG_CPU_HAS_SR_RB
static inline void local_irq_enable(void)
{
unsigned long __dummy0, __dummy1;
__asm__ __volatile__("stc sr, %0\n\t"
"and %1, %0\n\t"
"stc r6_bank, %1\n\t"
"or %1, %0\n\t"
"ldc %0, sr"
: "=&r" (__dummy0), "=r" (__dummy1)
: "1" (~0x000000f0)
: "memory");
}
#else
static inline void local_irq_enable(void)
{
unsigned long __dummy0, __dummy1;
__asm__ __volatile__ (
"stc sr, %0\n\t"
"and %1, %0\n\t"
"ldc %0, sr\n\t"
: "=&r" (__dummy0), "=r" (__dummy1)
: "1" (~0x000000f0)
: "memory");
}
#endif
static __inline__ void local_irq_disable(void)
{
unsigned long __dummy;
__asm__ __volatile__("stc sr, %0\n\t"
"or #0xf0, %0\n\t"
"ldc %0, sr"
: "=&z" (__dummy)
: /* no inputs */
: "memory");
}
#define local_save_flags(x) \
__asm__("stc sr, %0; and #0xf0, %0" : "=&z" (x) :/**/: "memory" )
#define irqs_disabled() \
({ \
unsigned long flags; \
local_save_flags(flags); \
(flags != 0); \
})
static __inline__ unsigned long local_irq_save(void)
{
unsigned long flags, __dummy;
__asm__ __volatile__("stc sr, %1\n\t"
"mov %1, %0\n\t"
"or #0xf0, %0\n\t"
"ldc %0, sr\n\t"
"mov %1, %0\n\t"
"and #0xf0, %0"
: "=&z" (flags), "=&r" (__dummy)
:/**/
: "memory" );
return flags;
}
#ifdef DEBUG_CLI_STI
static __inline__ void local_irq_restore(unsigned long x)
{
if ((x & 0x000000f0) != 0x000000f0)
local_irq_enable();
else {
unsigned long flags;
local_save_flags(flags);
if (flags == 0) {
extern void dump_stack(void);
printk(KERN_ERR "BUG!\n");
dump_stack();
local_irq_disable();
}
}
}
#else
#define local_irq_restore(x) do { \
if ((x & 0x000000f0) != 0x000000f0) \
local_irq_enable(); \
} while (0)
#endif
#define really_restore_flags(x) do { \
if ((x & 0x000000f0) != 0x000000f0) \
local_irq_enable(); \
else \
local_irq_disable(); \
} while (0)
/*
* Jump to P2 area.
* When handling TLB or caches, we need to do it from P2 area.
*/
#define jump_to_P2() \
do { \
unsigned long __dummy; \
__asm__ __volatile__( \
"mov.l 1f, %0\n\t" \
"or %1, %0\n\t" \
"jmp @%0\n\t" \
" nop\n\t" \
".balign 4\n" \
"1: .long 2f\n" \
"2:" \
: "=&r" (__dummy) \
: "r" (0x20000000)); \
} while (0)
/*
* Back to P1 area.
*/
#define back_to_P1() \
do { \
unsigned long __dummy; \
ctrl_barrier(); \
__asm__ __volatile__( \
"mov.l 1f, %0\n\t" \
"jmp @%0\n\t" \
" nop\n\t" \
".balign 4\n" \
"1: .long 2f\n" \
"2:" \
: "=&r" (__dummy)); \
} while (0)
/* For spinlocks etc */
#define local_irq_save(x) x = local_irq_save()
static __inline__ unsigned long xchg_u32(volatile int * m, unsigned long val)
{
unsigned long flags, retval;
local_irq_save(flags);
retval = *m;
*m = val;
local_irq_restore(flags);
return retval;
}
static __inline__ unsigned long xchg_u8(volatile unsigned char * m, unsigned long val)
{
unsigned long flags, retval;
local_irq_save(flags);
retval = *m;
*m = val & 0xff;
local_irq_restore(flags);
return retval;
}
static __inline__ unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
switch (size) {
case 4:
return xchg_u32(ptr, x);
break;
case 1:
return xchg_u8(ptr, x);
break;
}
__xchg_called_with_bad_pointer();
return x;
}
static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
unsigned long new)
{
__u32 retval;
unsigned long flags;
local_irq_save(flags);
retval = *m;
if (retval == old)
*m = new;
local_irq_restore(flags); /* implies memory barrier */
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);
#define __HAVE_ARCH_CMPXCHG 1
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);
}
__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))); \
})
/* XXX
* disable hlt during certain critical i/o operations
*/
#define HAVE_DISABLE_HLT
void disable_hlt(void);
void enable_hlt(void);
#define arch_align_stack(x) (x)
#endif