| #ifndef _M68K_SYSTEM_H |
| #define _M68K_SYSTEM_H |
| |
| #include <linux/linkage.h> |
| #include <linux/kernel.h> |
| #include <asm/segment.h> |
| #include <asm/entry.h> |
| |
| #ifdef __KERNEL__ |
| |
| /* |
| * switch_to(n) should switch tasks to task ptr, first checking that |
| * ptr isn't the current task, in which case it does nothing. This |
| * also clears the TS-flag if the task we switched to has used the |
| * math co-processor latest. |
| */ |
| /* |
| * switch_to() saves the extra registers, that are not saved |
| * automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and |
| * a0-a1. Some of these are used by schedule() and its predecessors |
| * and so we might get see unexpected behaviors when a task returns |
| * with unexpected register values. |
| * |
| * syscall stores these registers itself and none of them are used |
| * by syscall after the function in the syscall has been called. |
| * |
| * Beware that resume now expects *next to be in d1 and the offset of |
| * tss to be in a1. This saves a few instructions as we no longer have |
| * to push them onto the stack and read them back right after. |
| * |
| * 02/17/96 - Jes Sorensen (jds@kom.auc.dk) |
| * |
| * Changed 96/09/19 by Andreas Schwab |
| * pass prev in a0, next in a1 |
| */ |
| asmlinkage void resume(void); |
| #define switch_to(prev,next,last) do { \ |
| register void *_prev __asm__ ("a0") = (prev); \ |
| register void *_next __asm__ ("a1") = (next); \ |
| register void *_last __asm__ ("d1"); \ |
| __asm__ __volatile__("jbsr resume" \ |
| : "=a" (_prev), "=a" (_next), "=d" (_last) \ |
| : "0" (_prev), "1" (_next) \ |
| : "d0", "d2", "d3", "d4", "d5"); \ |
| (last) = _last; \ |
| } while (0) |
| |
| |
| /* |
| * Force strict CPU ordering. |
| * Not really required on m68k... |
| */ |
| #define nop() do { asm volatile ("nop"); barrier(); } while (0) |
| #define mb() barrier() |
| #define rmb() barrier() |
| #define wmb() barrier() |
| #define read_barrier_depends() ((void)0) |
| #define set_mb(var, value) ({ (var) = (value); wmb(); }) |
| |
| #define smp_mb() barrier() |
| #define smp_rmb() barrier() |
| #define smp_wmb() barrier() |
| #define smp_read_barrier_depends() ((void)0) |
| |
| /* interrupt control.. */ |
| #if 0 |
| #define local_irq_enable() asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory") |
| #else |
| #include <linux/hardirq.h> |
| #define local_irq_enable() ({ \ |
| if (MACH_IS_Q40 || !hardirq_count()) \ |
| asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory"); \ |
| }) |
| #endif |
| #define local_irq_disable() asm volatile ("oriw #0x0700,%%sr": : : "memory") |
| #define local_save_flags(x) asm volatile ("movew %%sr,%0":"=d" (x) : : "memory") |
| #define local_irq_restore(x) asm volatile ("movew %0,%%sr": :"d" (x) : "memory") |
| |
| static inline int irqs_disabled(void) |
| { |
| unsigned long flags; |
| local_save_flags(flags); |
| return flags & ~ALLOWINT; |
| } |
| |
| /* For spinlocks etc */ |
| #define local_irq_save(x) ({ local_save_flags(x); local_irq_disable(); }) |
| |
| #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) |
| |
| struct __xchg_dummy { unsigned long a[100]; }; |
| #define __xg(x) ((volatile struct __xchg_dummy *)(x)) |
| |
| #ifndef CONFIG_RMW_INSNS |
| static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) |
| { |
| unsigned long flags, tmp; |
| |
| local_irq_save(flags); |
| |
| switch (size) { |
| case 1: |
| tmp = *(u8 *)ptr; |
| *(u8 *)ptr = x; |
| x = tmp; |
| break; |
| case 2: |
| tmp = *(u16 *)ptr; |
| *(u16 *)ptr = x; |
| x = tmp; |
| break; |
| case 4: |
| tmp = *(u32 *)ptr; |
| *(u32 *)ptr = x; |
| x = tmp; |
| break; |
| default: |
| BUG(); |
| } |
| |
| local_irq_restore(flags); |
| return x; |
| } |
| #else |
| static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) |
| { |
| switch (size) { |
| case 1: |
| __asm__ __volatile__ |
| ("moveb %2,%0\n\t" |
| "1:\n\t" |
| "casb %0,%1,%2\n\t" |
| "jne 1b" |
| : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); |
| break; |
| case 2: |
| __asm__ __volatile__ |
| ("movew %2,%0\n\t" |
| "1:\n\t" |
| "casw %0,%1,%2\n\t" |
| "jne 1b" |
| : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); |
| break; |
| case 4: |
| __asm__ __volatile__ |
| ("movel %2,%0\n\t" |
| "1:\n\t" |
| "casl %0,%1,%2\n\t" |
| "jne 1b" |
| : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); |
| break; |
| } |
| return x; |
| } |
| #endif |
| |
| #include <asm-generic/cmpxchg-local.h> |
| |
| #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) |
| |
| /* |
| * Atomic compare and exchange. Compare OLD with MEM, if identical, |
| * store NEW in MEM. Return the initial value in MEM. Success is |
| * indicated by comparing RETURN with OLD. |
| */ |
| #ifdef CONFIG_RMW_INSNS |
| #define __HAVE_ARCH_CMPXCHG 1 |
| |
| static inline unsigned long __cmpxchg(volatile void *p, unsigned long old, |
| unsigned long new, int size) |
| { |
| switch (size) { |
| case 1: |
| __asm__ __volatile__ ("casb %0,%2,%1" |
| : "=d" (old), "=m" (*(char *)p) |
| : "d" (new), "0" (old), "m" (*(char *)p)); |
| break; |
| case 2: |
| __asm__ __volatile__ ("casw %0,%2,%1" |
| : "=d" (old), "=m" (*(short *)p) |
| : "d" (new), "0" (old), "m" (*(short *)p)); |
| break; |
| case 4: |
| __asm__ __volatile__ ("casl %0,%2,%1" |
| : "=d" (old), "=m" (*(int *)p) |
| : "d" (new), "0" (old), "m" (*(int *)p)); |
| break; |
| } |
| return old; |
| } |
| |
| #define cmpxchg(ptr, o, n) \ |
| ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \ |
| (unsigned long)(n), sizeof(*(ptr)))) |
| #define cmpxchg_local(ptr, o, n) \ |
| ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \ |
| (unsigned long)(n), sizeof(*(ptr)))) |
| #else |
| |
| /* |
| * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make |
| * them available. |
| */ |
| #define cmpxchg_local(ptr, o, n) \ |
| ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ |
| (unsigned long)(n), sizeof(*(ptr)))) |
| |
| #include <asm-generic/cmpxchg.h> |
| |
| #endif |
| |
| #define arch_align_stack(x) (x) |
| |
| #endif /* __KERNEL__ */ |
| |
| #endif /* _M68K_SYSTEM_H */ |