1 files changed, 158 insertions, 0 deletions

diff --git a/arch/h8300/include/asm/system.h b/arch/h8300/include/asm/system.h
new file mode 100644
index 000000000000..4b8e475908ae
--- /dev/null
+++ b/arch/h8300/include/asm/system.h
@@ -0,0 +1,158 @@
+#ifndef _H8300_SYSTEM_H
+#define _H8300_SYSTEM_H
+
+#include <linux/linkage.h>
+
+/*
+ * 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, offset of tss in d1, and whether
+ * the mm structures are shared in d2 (to avoid atc flushing).
+ *
+ * H8/300 Porting 2002/09/04 Yoshinori Sato
+ */
+
+asmlinkage void resume(void);
+#define switch_to(prev,next,last) {                         \
+  void *_last;                                              \
+  __asm__ __volatile__(                                     \
+                        "mov.l  %1, er0\n\t"                \
+                        "mov.l  %2, er1\n\t"                \
+                        "mov.l  %3, er2\n\t"                \
+                        "jsr @_resume\n\t"                  \
+                        "mov.l  er2,%0\n\t"                 \
+                       : "=r" (_last)                       \
+                       : "r" (&(prev->thread)),             \
+                         "r" (&(next->thread)),             \
+                         "g" (prev)                         \
+                       : "cc", "er0", "er1", "er2", "er3"); \
+  (last) = _last;                                           \
+}
+
+#define __sti() asm volatile ("andc #0x7f,ccr")
+#define __cli() asm volatile ("orc  #0x80,ccr")
+
+#define __save_flags(x) \
+       asm volatile ("stc ccr,%w0":"=r" (x))
+
+#define __restore_flags(x) \
+       asm volatile ("ldc %w0,ccr": :"r" (x))
+
+#define irqs_disabled()                 \
+({                                      \
+        unsigned char flags;            \
+        __save_flags(flags);            \
+        ((flags & 0x80) == 0x80);       \
+})
+
+#define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")
+
+/* For spinlocks etc */
+#define local_irq_disable()     __cli()
+#define local_irq_enable()      __sti()
+#define local_irq_save(x)       ({ __save_flags(x); local_irq_disable(); })
+#define local_irq_restore(x)    __restore_flags(x)
+#define local_save_flags(x)     __save_flags(x)
+
+/*
+ * Force strict CPU ordering.
+ * Not really required on H8...
+ */
+#define nop()  asm volatile ("nop"::)
+#define mb()   asm volatile (""   : : :"memory")
+#define rmb()  asm volatile (""   : : :"memory")
+#define wmb()  asm volatile (""   : : :"memory")
+#define set_mb(var, value) do { xchg(&var, value); } 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 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))
+
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+  unsigned long tmp, flags;
+
+  local_irq_save(flags);
+
+  switch (size) {
+  case 1:
+    __asm__ __volatile__
+    ("mov.b %2,%0\n\t"
+     "mov.b %1,%2"
+    : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
+    break;
+  case 2:
+    __asm__ __volatile__
+    ("mov.w %2,%0\n\t"
+     "mov.w %1,%2"
+    : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
+    break;
+  case 4:
+    __asm__ __volatile__
+    ("mov.l %2,%0\n\t"
+     "mov.l %1,%2"
+    : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)) : "memory");
+    break;
+  default:
+    tmp = 0;      
+  }
+  local_irq_restore(flags);
+  return tmp;
+}
+
+#define HARD_RESET_NOW() ({             \
+        local_irq_disable();            \
+        asm("jmp @@0");                 \
+})
+
+#include <asm-generic/cmpxchg-local.h>
+
+/*
+ * 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))))
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+#ifndef CONFIG_SMP
+#include <asm-generic/cmpxchg.h>
+#endif
+
+#define arch_align_stack(x) (x)
+
+#endif /* _H8300_SYSTEM_H */