patch-1.3.94 linux/include/asm-m68k/system.h

• Lines: 172
• Date: Sun Mar 31 18:38:57 1996
• Orig file: v1.3.93/linux/include/asm-m68k/system.h
• Orig date: Thu Jan 5 13:47:08 1995

diff -u --recursive --new-file v1.3.93/linux/include/asm-m68k/system.h linux/include/asm-m68k/system.h
@@ -1,53 +1,140 @@
+#ifndef _M68K_SYSTEM_H
+#define _M68K_SYSTEM_H
+
+#include <linux/config.h> /* get configuration macros */
+#include <linux/linkage.h>
+#include <asm/segment.h>
+
+extern inline unsigned long rdusp(void) {
+  	unsigned long usp;
+
+	__asm__ __volatile__("movec %/usp,%0"
+			     : "=d" (usp));
+	return usp;
+}
+
+extern inline void wrusp(unsigned long usp) {
+	__asm__ __volatile__("movec %0,%/usp"
+			     :
+			     : "d" (usp));
+}
+
 /*
- *  linux/include/asm-m68k/system.h
- *
- *  Copyright (C) 1991, 1992  Linus Torvalds
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file README.legal in the main directory of this archive
- * for more details.
+ * 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.
  */
-
 /*
- * 680x0 support added by Hamish Macdonald
+ * 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 regsiters 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)
  */
+asmlinkage void resume(void);
+#define switch_to(prev,next) { \
+  register int k __asm__ ("a1") = (int)&((struct task_struct *)0)->tss; \
+  register int n __asm__ ("d1") = (int)next; \
+  __asm__ __volatile__("jbsr " SYMBOL_NAME_STR(resume) "\n\t" \
+		       : : "a" (k), "d" (n) \
+		       : "d0", "d1", "d2", "d3", "d4", "d5", "a0", "a1"); \
+}
 
-#ifndef _M68K_SYSTEM_H
-#define _M68K_SYSTEM_H
+#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+#define tas(ptr) (xchg((ptr),1))
 
-#include <linux/config.h> /* get configuration macros */
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x) ((volatile struct __xchg_dummy *)(x))
 
 #if defined(CONFIG_ATARI) && !defined(CONFIG_AMIGA) && !defined(CONFIG_MAC)
 /* block out HSYNC on the atari */
-#define sti() __asm__ __volatile__ ("andiw #0xfbff,sr": : : "memory")
+#define sti() __asm__ __volatile__ ("andiw #0xfbff,%/sr": : : "memory")
 #else /* portable version */
-#define sti() __asm__ __volatile__ ("andiw #0xf8ff,sr": : : "memory")
+#define sti() __asm__ __volatile__ ("andiw #0xf8ff,%/sr": : : "memory")
 #endif /* machine compilation types */ 
-#define cli() __asm__ __volatile__ ("oriw  #0x0700,sr": : : "memory")
+#define cli() __asm__ __volatile__ ("oriw  #0x0700,%/sr": : : "memory")
 #define nop() __asm__ __volatile__ ("nop"::)
 
 #define save_flags(x) \
-__asm__ __volatile__("movew sr,%0":"=d" (x) : /* no input */ :"memory")
+__asm__ __volatile__("movew %/sr,%0":"=d" (x) : /* no input */ :"memory")
 
 #define restore_flags(x) \
-__asm__ __volatile__("movew %0,sr": /* no outputs */ :"d" (x) : "memory")
+__asm__ __volatile__("movew %0,%/sr": /* no outputs */ :"d" (x) : "memory")
 
 #define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")
 
-#define move_to_user_mode() \
-    __asm__ __volatile__ ("movel sp,usp\n\t"     /* setup user sp       */ \
-			  "movec %0,msp\n\t"     /* setup kernel sp     */ \
-			  "andiw #0xdfff,sr"     /* return to user mode */ \
-			  : /* no output */                                \
-			  : "r" (current->kernel_stack_page + PAGE_SIZE)   \
-			  : "memory", "sp")
-
-static inline void clear_fpu(void) {
-	unsigned long nilstate = 0;
-	__asm__ __volatile__ ("frestore %0@" : : "a" (&nilstate));
+#if 1
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+  unsigned long tmp, flags;
+
+  save_flags(flags);
+  cli();
+
+  switch (size) {
+  case 1:
+    __asm__ __volatile__
+    ("moveb %2,%0\n\t"
+     "moveb %1,%2"
+    : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
+    break;
+  case 2:
+    __asm__ __volatile__
+    ("movew %2,%0\n\t"
+     "movew %1,%2"
+    : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
+    break;
+  case 4:
+    __asm__ __volatile__
+    ("movel %2,%0\n\t"
+     "movel %1,%2"
+    : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
+    break;
+  }
+  restore_flags(flags);
+  return tmp;
 }
-
-#define halt() \
-        __asm__ __volatile__ ("halt")
+#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
 
 #endif /* _M68K_SYSTEM_H */