Folks,

Here's a revised profiling patch that includes that stack adjustment to
get things working as pointed out by Ethan Solomita, and inlines the
clearing and setting of the master interrupt bit of the status register
instead of calling splraise/splset so there's no unnecessary function
call overhead.

Two questions though.  I don't think I need to declare $at as a used
register in MCOUNT_ENTER - does anyone know for sure?  Related to this,
MCOUNT saves and restores $at - would the compiler use $at in normal use
or can we discard those instructions?

Other than these minor things, can anyone see any problems with this?

Simon.
--
Index: profile.h
===================================================================
RCS file: /cvsroot/syssrc/sys/arch/mips/include/profile.h,v
retrieving revision 1.13
diff -p -u -r1.13 profile.h
--- profile.h	2000/03/28 02:58:46	1.13
+++ profile.h	2000/04/08 06:58:25
@@ -42,28 +42,13 @@
 #define _MIPS_PROFILE_H_
 
 #ifdef _KERNEL
- /*
-  *  Declare non-profiled _splhigh() /_splx() entrypoints for _mcount.
-  *  see MCOUNT_ENTER and MCOUNT_EXIT.
-  */
-#define	_KERNEL_MCOUNT_DECL 		\
-	int _splhigh __P((void));	\
-	int _splx __P((int));
-#else   /* !_KERNEL */
-/* Make __mcount static. */
-#define	_KERNEL_MCOUNT_DECL	static
-#endif	/* !_KERNEL */
-
-#ifdef _KERNEL
 # define _PROF_CPLOAD	""
 #else
 # define _PROF_CPLOAD	".cpload $25;"
 #endif
 
-
 #define	_MCOUNT_DECL \
-    _KERNEL_MCOUNT_DECL \
-    void __attribute__((unused)) __mcount
+    static void __attribute__((unused)) __mcount
 
 #define	MCOUNT \
 	__asm__(".globl _mcount;" \
@@ -72,6 +57,7 @@
 	".set noreorder;" \
 	".set noat;" \
 	_PROF_CPLOAD \
+	"subu $29,$29,16;" \
 	"sw $4,8($29);" \
 	"sw $5,12($29);" \
 	"sw $6,16($29);" \
@@ -87,7 +73,7 @@
 	"lw $7,20($29);" \
 	"lw $31,4($29);" \
 	"lw $1,0($29);" \
-	"addu $29,$29,8;" \
+	"addu $29,$29,24;" \
 	"j $31;" \
 	"move $31,$1;" \
 	".set reorder;" \
@@ -95,14 +81,38 @@
 
 #ifdef _KERNEL
 /*
- * The following two macros do splhigh and splx respectively.
- * They have to be defined this way because these are real
- * functions on the MIPS, and we do not want to invoke mcount
- * recursively.
+ * Block interrupts during mcount so that those interrupts can also be
+ * counted (as soon as we get done with the current counting).
  */
-#define	MCOUNT_ENTER	s = _splhigh()
 
-#define	MCOUNT_EXIT	_splx(s)
-#endif /* _KERNEL */
+/* $1 is at, $8 is t0, $12 is MIPS_COP_0_STATUS */
+#define	MCOUNT_ENTER	__asm__( \
+	".set	noat;" \
+	".set	noreorder;" \
+	"mfc0	$1,$12;" \
+	"nop;" \
+	"andi	%0,$1,1;" \
+	"beq	$1,$0,1f;" \
+	"li	$8,-2;" \
+	"and	$1,$1,$8;" \
+	"mtc0	$1,$12;" \
+	"nop;" \
+	"1:;" \
+	".set	at;" \
+	".set	reorder" : "=g" (s) :: "t0", "at");
+
+#define	MCOUNT_EXIT	__asm__( \
+	".set	noat;" \
+	".set	noreorder;" \
+	"beq	%0,$0,1f;" \
+	"mfc0	$1,$12;" \
+	"nop;" \
+	"ori	$1,$1,1;" \
+	"mtc0	$1,$12;" \
+	"nop;" \
+	"1:;" \
+	".set	at;" \
+	".set	reorder" :: "g" (s) : "at");
 
+#endif /* _KERNEL */
 #endif /* _MIPS_PROFILE_H_ */