patch-2.4.22 linux-2.4.22/arch/arm/lib/delay.S

• Lines: 88
• Date: 2003-08-25 04:44:39.000000000 -0700
• Orig file: linux-2.4.21/arch/arm/lib/delay.S
• Orig date: 2001-04-12 12:20:31.000000000 -0700

diff -urN linux-2.4.21/arch/arm/lib/delay.S linux-2.4.22/arch/arm/lib/delay.S
@@ -1,7 +1,7 @@
 /*
  *  linux/arch/arm/lib/delay.S
  *
- *  Copyright (C) 1995, 1996 Russell King
+ *  Copyright (C) 1995-2003 Russell King
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -9,45 +9,52 @@
  */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
-		.text
+#include <asm/delay.h>
 
-LC0:		.word	SYMBOL_NAME(loops_per_jiffy)
+		.text
 
 /*
- * 0 <= r0 <= 2000
+ * See linux/include/asm-arm/delay.h for a description of the maths.
  */
-ENTRY(udelay)
-		mov	r2,     #0x6800
-		orr	r2, r2, #0x00db
+
+#if NDELAY_FACTOR > 255
+#error NDELAY_FACTOR out of range
+#endif
+#if UDELAY_FACTOR > 65535
+#error UDELAY_FACTOR out of range
+#endif
+
+LC0:		.word	SYMBOL_NAME(loops_per_jiffy)
+
+ENTRY(__const_delay)
+		ldr	r3, LC0
+		mov	r1, r0, lsr #11
+		ldr	r2, [r3, #0]
+		b	2f
+
+ENTRY(__ndelay)
+		mov	r2, #NDELAY_FACTOR
+		b	1f
+
+ENTRY(__udelay)
+		mov	r2,     #UDELAY_FACTOR & 0xff00
+		orr	r2, r2, #UDELAY_FACTOR & 0x00ff
+1:		ldr	r3, LC0
 		mul	r1, r0, r2
-		ldr	r2, LC0
-		ldr	r2, [r2]
+		ldr	r2, [r3, #0]
 		mov	r1, r1, lsr #11
-		mov	r2, r2, lsr #11
+2:		mov	r2, r2, lsr #12
 		mul	r0, r1, r2
-		movs	r0, r0, lsr #6
+		movs	r0, r0, lsr #5
 		RETINSTR(moveq,pc,lr)
 
 /*
- * loops = (r0 * 0x10c6 * 100 * loops_per_jiffie) / 2^32
+ * loops = (r0 * 0x10c6 * HZ * loops_per_jiffy) / 2^32
+ *
+ * Oh, if only we had a cycle counter...
  */
 
-@ Delay routine
 ENTRY(__delay)
 		subs	r0, r0, #1
-		RETINSTR(movcc,pc,lr)
-		subs	r0, r0, #1
-		RETINSTR(movcc,pc,lr)
-		subs	r0, r0, #1
-		RETINSTR(movcc,pc,lr)
-		subs	r0, r0, #1
-		RETINSTR(movcc,pc,lr)
-		subs	r0, r0, #1
-		RETINSTR(movcc,pc,lr)
-		subs	r0, r0, #1
-		RETINSTR(movcc,pc,lr)
-		subs	r0, r0, #1
-		RETINSTR(movcc,pc,lr)
-		subs	r0, r0, #1
 		bcs	SYMBOL_NAME(__delay)
 		RETINSTR(mov,pc,lr)