2006-11-07 00:21:53

by Kevin Hilman

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Subject: [PATCH 2.6.18-rt7 1/1] ARM: add latency timing support

Add latency-timing support for IXP4xx.

Signed-off-by: Kevin Hilman <[email protected]>

Index: linux-2.6.18/include/asm-arm/arch-ixp4xx/timex.h
===================================================================
--- linux-2.6.18.orig/include/asm-arm/arch-ixp4xx/timex.h
+++ linux-2.6.18/include/asm-arm/arch-ixp4xx/timex.h
@@ -13,3 +13,11 @@
#define FREQ 66666666
#define CLOCK_TICK_RATE (((FREQ / HZ & ~IXP4XX_OST_RELOAD_MASK) + 1) * HZ)

+extern u64 ixp4xx_get_cycles(void);
+#define mach_read_cycles() ixp4xx_get_cycles()
+
+#ifdef CONFIG_LATENCY_TIMING
+#define mach_cycles_to_usecs(d) (((d) * ((1000000LL << 32) / CLOCK_TICK_RATE)) >> 32)
+#define mach_usecs_to_cycles(d) (((d) * (((long long)CLOCK_TICK_RATE << 32) / 1000000)) >> 32)
+#endif
+
Index: linux-2.6.18/include/asm-arm/timex.h
===================================================================
--- linux-2.6.18.orig/include/asm-arm/timex.h
+++ linux-2.6.18/include/asm-arm/timex.h
@@ -19,8 +19,12 @@ typedef unsigned long cycles_t;
#ifndef mach_read_cycles
#define mach_read_cycles() (0)
#ifdef CONFIG_LATENCY_TIMING
- #define mach_cycles_to_usecs(d) (d)
- #define mach_usecs_to_cycles(d) (d)
+ #ifndef mach_cycles_to_usecs
+ #define mach_cycles_to_usecs(d) (d)
+ #endif
+ #ifndef mach_usecs_to_cycles
+ #define mach_usecs_to_cycles(d) (d)
+ #endif
#endif
#endif

--


2006-11-07 16:43:43

by Kevin Hilman

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Subject: Re: [PATCH 2.6.18-rt7 1/1] ARM: add latency timing support

Kevin Hilman wrote:
> Add latency-timing support for IXP4xx.

On second thought, here's a better patch that will cover all ARM
subarches. Each sub-arch only has to implement mach_get_cycles()

Signed-off-by: Kevin Hilman <[email protected]>


Attachments:
arm_latency_timing.patch (1.58 kB)