From: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
To: "Andrew Morton" <akpm@osdl.org>, "john stultz" <johnstul@us.ibm.com>
Cc: <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] linux-2.6.0-test4_cyclone-hpet-fix_A0
Date: Thu, 4 Sep 2003 10:21:55 -0700 [thread overview]
Message-ID: <C8C38546F90ABF408A5961FC01FDBF1902C7D23C@fmsmsx405.fm.intel.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 1413 bytes --]
> -----Original Message-----
> From: Andrew Morton [mailto:akpm@osdl.org]
>
> john stultz <johnstul@us.ibm.com> wrote:
> >
> > Anyway, the HPET changes made calibrate_tsc() static, which
> it probably
> > should be, but it broke the timer_cyclone code. This patch
> fixes it back
> > up by re-implementing calibrate_tsc() locally as it was done in
> > timer_hpet.c
>
> <stdrant>
> Of course if some bozo had stuck this:
>
> extern unsigned long calibrate_tsc(void);
>
> in a header file rather than in a .c file (timer_cyclone.c),
> this problem
> would not have occurred. Nevereverever put extern
> declarations in .c files!
> </stdrant>
My fault. I should have atleast test compiled cyclone timer code.
> Can we not we avoid the cut-n-paste coding?
>
> There is also timer_tsc.c:calibrate_tsc_hpet() which is
> almost the same as
> timer_hpet.c:calibrate_tsc(). Seem to me that we could tweak
> calibrate_tsc_hpet() a bit, unstaticalise
> timer_tsc.c:calibrate_tsc() and
> have two functions rather than four?
>
How about the attached patch (against mm4), that moves all
calibrate tsc functions into a common file, avoiding the duplication.
This time I could successfully compile cyclone timer too :). However,
I had to do an unrelated one line change in fixmap (last chunk in
the patch) to compile for summit.
Thanks,
-Venkatesh
[-- Attachment #2: mm4-hpet-fix.patch --]
[-- Type: application/octet-stream, Size: 13007 bytes --]
diff -purN linux-2.6.0-test4-mm4/arch/i386/kernel/timers/common.c linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/common.c
--- linux-2.6.0-test4-mm4/arch/i386/kernel/timers/common.c 1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/common.c 2003-09-04 11:57:47.000000000 -0700
@@ -0,0 +1,138 @@
+/*
+ * Common functions used across the timers go here
+ */
+
+#include <linux/init.h>
+#include <linux/timex.h>
+#include <linux/errno.h>
+
+#include <asm/timer.h>
+#include <asm/hpet.h>
+
+#include "mach_timer.h"
+
+/* ------ Calibrate the TSC -------
+ * Return 2^32 * (1 / (TSC clocks per usec)) for do_fast_gettimeoffset().
+ * Too much 64-bit arithmetic here to do this cleanly in C, and for
+ * accuracy's sake we want to keep the overhead on the CTC speaker (channel 2)
+ * output busy loop as low as possible. We avoid reading the CTC registers
+ * directly because of the awkward 8-bit access mechanism of the 82C54
+ * device.
+ */
+
+#define CALIBRATE_TIME (5 * 1000020/HZ)
+
+unsigned long __init calibrate_tsc(void)
+{
+ mach_prepare_counter();
+
+ {
+ unsigned long startlow, starthigh;
+ unsigned long endlow, endhigh;
+ unsigned long count;
+
+ rdtsc(startlow,starthigh);
+ mach_countup(&count);
+ rdtsc(endlow,endhigh);
+
+
+ /* Error: ECTCNEVERSET */
+ if (count <= 1)
+ goto bad_ctc;
+
+ /* 64-bit subtract - gcc just messes up with long longs */
+ __asm__("subl %2,%0\n\t"
+ "sbbl %3,%1"
+ :"=a" (endlow), "=d" (endhigh)
+ :"g" (startlow), "g" (starthigh),
+ "0" (endlow), "1" (endhigh));
+
+ /* Error: ECPUTOOFAST */
+ if (endhigh)
+ goto bad_ctc;
+
+ /* Error: ECPUTOOSLOW */
+ if (endlow <= CALIBRATE_TIME)
+ goto bad_ctc;
+
+ __asm__("divl %2"
+ :"=a" (endlow), "=d" (endhigh)
+ :"r" (endlow), "0" (0), "1" (CALIBRATE_TIME));
+
+ return endlow;
+ }
+
+ /*
+ * The CTC wasn't reliable: we got a hit on the very first read,
+ * or the CPU was so fast/slow that the quotient wouldn't fit in
+ * 32 bits..
+ */
+bad_ctc:
+ return 0;
+}
+
+#ifdef CONFIG_HPET_TIMER
+/* ------ Calibrate the TSC using HPET -------
+ * Return 2^32 * (1 / (TSC clocks per usec)) for getting the CPU freq.
+ * Second output is parameter 1 (when non NULL)
+ * Set 2^32 * (1 / (tsc per HPET clk)) for delay_hpet().
+ * calibrate_tsc() calibrates the processor TSC by comparing
+ * it to the HPET timer of known frequency.
+ * Too much 64-bit arithmetic here to do this cleanly in C
+ */
+#define CALIBRATE_CNT_HPET (5 * hpet_tick)
+#define CALIBRATE_TIME_HPET (5 * KERNEL_TICK_USEC)
+
+unsigned long __init calibrate_tsc_hpet(unsigned long *tsc_hpet_quotient_ptr)
+{
+ unsigned long tsc_startlow, tsc_starthigh;
+ unsigned long tsc_endlow, tsc_endhigh;
+ unsigned long hpet_start, hpet_end;
+ unsigned long result, remain;
+
+ hpet_start = hpet_readl(HPET_COUNTER);
+ rdtsc(tsc_startlow, tsc_starthigh);
+ do {
+ hpet_end = hpet_readl(HPET_COUNTER);
+ } while ((hpet_end - hpet_start) < CALIBRATE_CNT_HPET);
+ rdtsc(tsc_endlow, tsc_endhigh);
+
+ /* 64-bit subtract - gcc just messes up with long longs */
+ __asm__("subl %2,%0\n\t"
+ "sbbl %3,%1"
+ :"=a" (tsc_endlow), "=d" (tsc_endhigh)
+ :"g" (tsc_startlow), "g" (tsc_starthigh),
+ "0" (tsc_endlow), "1" (tsc_endhigh));
+
+ /* Error: ECPUTOOFAST */
+ if (tsc_endhigh)
+ goto bad_calibration;
+
+ /* Error: ECPUTOOSLOW */
+ if (tsc_endlow <= CALIBRATE_TIME_HPET)
+ goto bad_calibration;
+
+ ASM_DIV64_REG(result, remain, tsc_endlow, 0, CALIBRATE_TIME_HPET);
+ if (remain > (tsc_endlow >> 1))
+ result++; /* rounding the result */
+
+ if (tsc_hpet_quotient_ptr) {
+ unsigned long tsc_hpet_quotient;
+
+ ASM_DIV64_REG(tsc_hpet_quotient, remain, tsc_endlow, 0,
+ CALIBRATE_CNT_HPET);
+ if (remain > (tsc_endlow >> 1))
+ tsc_hpet_quotient++; /* rounding the result */
+ *tsc_hpet_quotient_ptr = tsc_hpet_quotient;
+ }
+
+ return result;
+bad_calibration:
+ /*
+ * the CPU was so fast/slow that the quotient wouldn't fit in
+ * 32 bits..
+ */
+ return 0;
+}
+#endif
+
diff -purN linux-2.6.0-test4-mm4/arch/i386/kernel/timers/Makefile linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/Makefile
--- linux-2.6.0-test4-mm4/arch/i386/kernel/timers/Makefile 2003-09-02 17:56:48.000000000 -0700
+++ linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/Makefile 2003-09-04 11:33:04.000000000 -0700
@@ -2,7 +2,7 @@
# Makefile for x86 timers
#
-obj-y := timer.o timer_none.o timer_tsc.o timer_pit.o
+obj-y := timer.o timer_none.o timer_tsc.o timer_pit.o common.o
obj-$(CONFIG_X86_CYCLONE_TIMER) += timer_cyclone.o
obj-$(CONFIG_HPET_TIMER) += timer_hpet.o
diff -purN linux-2.6.0-test4-mm4/arch/i386/kernel/timers/timer_cyclone.c linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/timer_cyclone.c
--- linux-2.6.0-test4-mm4/arch/i386/kernel/timers/timer_cyclone.c 2003-08-22 16:57:49.000000000 -0700
+++ linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/timer_cyclone.c 2003-09-04 11:57:42.000000000 -0700
@@ -19,7 +19,6 @@
#include <asm/fixmap.h>
extern spinlock_t i8253_lock;
-extern unsigned long calibrate_tsc(void);
/* Number of usecs that the last interrupt was delayed */
static int delay_at_last_interrupt;
diff -purN linux-2.6.0-test4-mm4/arch/i386/kernel/timers/timer_hpet.c linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/timer_hpet.c
--- linux-2.6.0-test4-mm4/arch/i386/kernel/timers/timer_hpet.c 2003-09-02 17:56:48.000000000 -0700
+++ linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/timer_hpet.c 2003-09-04 11:57:38.000000000 -0700
@@ -131,63 +131,6 @@ void delay_hpet(unsigned long loops)
} while ((hpet_end - hpet_start) < (loops));
}
-/* ------ Calibrate the TSC -------
- * Return 2^32 * (1 / (TSC clocks per usec)) for getting the CPU freq.
- * Set 2^32 * (1 / (tsc per HPET clk)) for delay_hpet().
- * calibrate_tsc() calibrates the processor TSC by comparing
- * it to the HPET timer of known frequency.
- * Too much 64-bit arithmetic here to do this cleanly in C
- */
-#define CALIBRATE_CNT_HPET (5 * hpet_tick)
-#define CALIBRATE_TIME_HPET (5 * KERNEL_TICK_USEC)
-
-static unsigned long __init calibrate_tsc(void)
-{
- unsigned long tsc_startlow, tsc_starthigh;
- unsigned long tsc_endlow, tsc_endhigh;
- unsigned long hpet_start, hpet_end;
- unsigned long result, remain;
-
- hpet_start = hpet_readl(HPET_COUNTER);
- rdtsc(tsc_startlow, tsc_starthigh);
- do {
- hpet_end = hpet_readl(HPET_COUNTER);
- } while ((hpet_end - hpet_start) < CALIBRATE_CNT_HPET);
- rdtsc(tsc_endlow, tsc_endhigh);
-
- /* 64-bit subtract - gcc just messes up with long longs */
- __asm__("subl %2,%0\n\t"
- "sbbl %3,%1"
- :"=a" (tsc_endlow), "=d" (tsc_endhigh)
- :"g" (tsc_startlow), "g" (tsc_starthigh),
- "0" (tsc_endlow), "1" (tsc_endhigh));
-
- /* Error: ECPUTOOFAST */
- if (tsc_endhigh)
- goto bad_calibration;
-
- /* Error: ECPUTOOSLOW */
- if (tsc_endlow <= CALIBRATE_TIME_HPET)
- goto bad_calibration;
-
- ASM_DIV64_REG(result, remain, tsc_endlow, 0, CALIBRATE_TIME_HPET);
- if (remain > (tsc_endlow >> 1))
- result++; /* rounding the result */
-
- ASM_DIV64_REG(tsc_hpet_quotient, remain, tsc_endlow, 0,
- CALIBRATE_CNT_HPET);
- if (remain > (tsc_endlow >> 1))
- tsc_hpet_quotient++; /* rounding the result */
-
- return result;
-bad_calibration:
- /*
- * the CPU was so fast/slow that the quotient wouldn't fit in
- * 32 bits..
- */
- return 0;
-}
-
static int __init init_hpet(char* override)
{
unsigned long result, remain;
@@ -201,7 +144,7 @@ static int __init init_hpet(char* overri
printk("Using HPET for gettimeofday\n");
if (cpu_has_tsc) {
- unsigned long tsc_quotient = calibrate_tsc();
+ unsigned long tsc_quotient = calibrate_tsc_hpet(&tsc_hpet_quotient);
if (tsc_quotient) {
/* report CPU clock rate in Hz.
* The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
diff -purN linux-2.6.0-test4-mm4/arch/i386/kernel/timers/timer_tsc.c linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/timer_tsc.c
--- linux-2.6.0-test4-mm4/arch/i386/kernel/timers/timer_tsc.c 2003-09-02 17:56:48.000000000 -0700
+++ linux-2.6.0-test4-mm4-fix/arch/i386/kernel/timers/timer_tsc.c 2003-09-04 11:57:35.000000000 -0700
@@ -254,67 +254,6 @@ static void delay_tsc(unsigned long loop
} while ((now-bclock) < loops);
}
-/* ------ Calibrate the TSC -------
- * Return 2^32 * (1 / (TSC clocks per usec)) for do_fast_gettimeoffset().
- * Too much 64-bit arithmetic here to do this cleanly in C, and for
- * accuracy's sake we want to keep the overhead on the CTC speaker (channel 2)
- * output busy loop as low as possible. We avoid reading the CTC registers
- * directly because of the awkward 8-bit access mechanism of the 82C54
- * device.
- */
-
-#define CALIBRATE_TIME (5 * 1000020/HZ)
-
-static unsigned long __init calibrate_tsc(void)
-{
- mach_prepare_counter();
-
- {
- unsigned long startlow, starthigh;
- unsigned long endlow, endhigh;
- unsigned long count;
-
- rdtsc(startlow,starthigh);
- mach_countup(&count);
- rdtsc(endlow,endhigh);
-
- last_tsc_low = endlow;
-
- /* Error: ECTCNEVERSET */
- if (count <= 1)
- goto bad_ctc;
-
- /* 64-bit subtract - gcc just messes up with long longs */
- __asm__("subl %2,%0\n\t"
- "sbbl %3,%1"
- :"=a" (endlow), "=d" (endhigh)
- :"g" (startlow), "g" (starthigh),
- "0" (endlow), "1" (endhigh));
-
- /* Error: ECPUTOOFAST */
- if (endhigh)
- goto bad_ctc;
-
- /* Error: ECPUTOOSLOW */
- if (endlow <= CALIBRATE_TIME)
- goto bad_ctc;
-
- __asm__("divl %2"
- :"=a" (endlow), "=d" (endhigh)
- :"r" (endlow), "0" (0), "1" (CALIBRATE_TIME));
-
- return endlow;
- }
-
- /*
- * The CTC wasn't reliable: we got a hit on the very first read,
- * or the CPU was so fast/slow that the quotient wouldn't fit in
- * 32 bits..
- */
-bad_ctc:
- return 0;
-}
-
#ifdef CONFIG_HPET_TIMER
static void mark_offset_tsc_hpet(void)
{
@@ -363,58 +302,6 @@ static void mark_offset_tsc_hpet(void)
ASM_MUL64_REG(temp, delay_at_last_interrupt,
hpet_usec_quotient, delay_at_last_interrupt);
}
-
-/* ------ Calibrate the TSC based on HPET timer -------
- * Return 2^32 * (1 / (TSC clocks per usec)) for do_fast_gettimeoffset().
- * calibrate_tsc() calibrates the processor TSC by comparing
- * it to the HPET timer of known frequency.
- * Too much 64-bit arithmetic here to do this cleanly in C
- */
-
-#define CALIBRATE_CNT_HPET (5 * hpet_tick)
-#define CALIBRATE_TIME_HPET (5 * KERNEL_TICK_USEC)
-
-unsigned long __init calibrate_tsc_hpet(void)
-{
- unsigned long tsc_startlow, tsc_starthigh;
- unsigned long tsc_endlow, tsc_endhigh;
- unsigned long hpet_start, hpet_end;
- unsigned long result, remain;
-
- hpet_start = hpet_readl(HPET_COUNTER);
- rdtsc(tsc_startlow, tsc_starthigh);
- do {
- hpet_end = hpet_readl(HPET_COUNTER);
- } while ((hpet_end - hpet_start) < CALIBRATE_CNT_HPET);
- rdtsc(tsc_endlow, tsc_endhigh);
-
- /* 64-bit subtract - gcc just messes up with long longs */
- __asm__("subl %2,%0\n\t"
- "sbbl %3,%1"
- :"=a" (tsc_endlow), "=d" (tsc_endhigh)
- :"g" (tsc_startlow), "g" (tsc_starthigh),
- "0" (tsc_endlow), "1" (tsc_endhigh));
-
- /* Error: ECPUTOOFAST */
- if (tsc_endhigh)
- goto bad_calibration;
-
- /* Error: ECPUTOOSLOW */
- if (tsc_endlow <= CALIBRATE_TIME_HPET)
- goto bad_calibration;
-
- ASM_DIV64_REG(result, remain, tsc_endlow, 0, CALIBRATE_TIME_HPET);
- if (remain > (tsc_endlow >> 1))
- result++; /* rounding the result */
-
- return result;
-bad_calibration:
- /*
- * the CPU was so fast/slow that the quotient wouldn't fit in
- * 32 bits..
- */
- return 0;
-}
#endif
#ifdef CONFIG_CPU_FREQ
@@ -515,7 +402,7 @@ static int __init init_tsc(char* overrid
if (is_hpet_enabled()){
unsigned long result, remain;
printk("Using TSC for gettimeofday\n");
- tsc_quotient = calibrate_tsc_hpet();
+ tsc_quotient = calibrate_tsc_hpet(NULL);
timer_tsc.mark_offset = &mark_offset_tsc_hpet;
/*
* Math to calculate hpet to usec multiplier
diff -purN linux-2.6.0-test4-mm4/include/asm-i386/timer.h linux-2.6.0-test4-mm4-fix/include/asm-i386/timer.h
--- linux-2.6.0-test4-mm4/include/asm-i386/timer.h 2003-09-02 17:56:48.000000000 -0700
+++ linux-2.6.0-test4-mm4-fix/include/asm-i386/timer.h 2003-09-04 11:21:24.000000000 -0700
@@ -38,8 +38,10 @@ extern struct timer_opts timer_tsc;
extern struct timer_opts timer_cyclone;
#endif
+extern unsigned long calibrate_tsc(void);
#ifdef CONFIG_HPET_TIMER
extern struct timer_opts timer_hpet;
+extern unsigned long calibrate_tsc_hpet(unsigned long *tsc_hpet_quotient_ptr);
#endif
#endif
diff -purN linux-2.6.0-test4-mm4/include/asm-i386/fixmap.h linux-2.6.0-test4-mm4-fix/include/asm-i386/fixmap.h
--- linux-2.6.0-test4-mm4/include/asm-i386/fixmap.h 2003-09-02 17:56:48.000000000 -0700
+++ linux-2.6.0-test4-mm4-fix/include/asm-i386/fixmap.h 2003-09-04 11:42:13.000000000 -0700
@@ -73,7 +73,7 @@ enum fixed_addresses {
FIX_TSS_0,
FIX_ENTRY_TRAMPOLINE_1,
FIX_ENTRY_TRAMPOLINE_0,
-#ifdef CONFIG_X86_CYCLONE
+#ifdef CONFIG_X86_CYCLONE_TIMER
FIX_CYCLONE_TIMER, /*cyclone timer register*/
FIX_VSTACK_HOLE_2,
#endif
next reply other threads:[~2003-09-04 17:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-04 17:21 Pallipadi, Venkatesh [this message]
2003-09-04 17:53 ` [PATCH] linux-2.6.0-test4_cyclone-hpet-fix_A0 john stultz
2003-09-04 18:04 ` Andrew Morton
-- strict thread matches above, loose matches on Subject: below --
2003-09-04 18:23 Pallipadi, Venkatesh
2003-09-04 4:29 john stultz
2003-09-04 5:59 ` Andrew Morton
2003-09-04 7:14 ` john stultz
2003-09-04 14:48 ` Martin J. Bligh
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