PPC 44x Watchdog timer

PPC 44x Watchdog timer

[Glenn Burkhardt]

Is there a patch for the built in watchdog timer in the 440GP available
anywhere for the 2.4 kernel (viz., ELDK kernels)?

I found a driver for the 2.6 kernel in the mailing list submitted
by Takeharu KATO last February, and, if nothing else is available, plan
to back fit it to the 2.4 kernel.

Thanks!

Re: PPC 44x Watchdog timer

[Takeharu KATO]

Hi

IIRC, MontaVistaLinux has this feature.
As far as I know, I found it in Monta Vista Linux 3 years ago at least.
I've not checked resent kernel of Monta Vista Linux, so I am sorry if
it is wrong now.

Glenn Burkhardt wrote:
> Is there a patch for the built in watchdog timer in the 440GP available
> anywhere for the 2.4 kernel (viz., ELDK kernels)?
> 
By the way, BOOKE_WDT patch has not been commited to up-stream kernel.
Matt(or Kumar?), please apply the patch.

Regards,

Re: PPC 44x Watchdog timer

[Glenn Burkhardt]

After looking at the current BitKeeper 2.4 development tree on 
source.mvista.com, it looks like the use of the hardware watchdog timer was 
discontinued at some point in favor of using the general purpose timer.  The 
watchdog exception interrupt isn't used, and it's only configurable for 
PPC405 (although I think that the technique would work for the whole 4xx 
family).

Or am I misreading the code?

It would also be nice if your patch were applied to the 2.6 kernel tree.

On Wednesday 20 April 2005 07:35 am, Takeharu KATO wrote:
> Hi
>
> IIRC, MontaVistaLinux has this feature.
> As far as I know, I found it in Monta Vista Linux 3 years ago at least.
> I've not checked resent kernel of Monta Vista Linux, so I am sorry if
> it is wrong now.
>
> Glenn Burkhardt wrote:
> > Is there a patch for the built in watchdog timer in the 440GP available
> > anywhere for the 2.4 kernel (viz., ELDK kernels)?
>
> By the way, BOOKE_WDT patch has not been commited to up-stream kernel.
> Matt(or Kumar?), please apply the patch.
>
> Regards,

Re: PPC 44x Watchdog timer

[Takeharu KATO]

Hi

Glenn Burkhardt wrote:

> watchdog exception interrupt isn't used, and it's only configurable for 
> PPC405 (although I think that the technique would work for the whole 4xx 
> family).
> 
> Or am I misreading the code?
> 
No, the kernel which I mentioned before is MontaVistaLinux.
IIRC, I look the WDT relevant codes in MontaVistaLinux2.X few years ago.
Of course, It was prepared for PowerPC40X...

> It would also be nice if your patch were applied to the 2.6 kernel tree.
> 
Sorry, It's not my jurisdiction.
Matt(Porter) or Kumar(Gala) may be responsible for this work.
#Finally, the patch should be approved by akpm and linus, of course...

Matt or Kumar, would you merge BOOKE_WDT patch to 2.6 kernel tree?
IIRC, This patch has been left under review state about two month.
Is there something to be needed for the patch?

Re: PPC 44x Watchdog timer

[Kumar Gala]

On May 4, 2005, at 9:07 PM, Takeharu KATO wrote:

> Hi
>
> Glenn Burkhardt wrote:
>
> > watchdog exception interrupt isn't used, and it's only configurable 
> for
> > PPC405 (although I think that the technique would work for the whole 
> 4xx
> > family).
>  >
> > Or am I misreading the code?
>  >
> No, the kernel which I mentioned before is MontaVistaLinux.
> IIRC, I look the WDT relevant codes in MontaVistaLinux2.X few years 
> ago.
> Of course, It was prepared for PowerPC40X...
>
> > It would also be nice if your patch were applied to the 2.6 kernel 
> tree.
> >
> Sorry, It's not my jurisdiction.
> Matt(Porter) or Kumar(Gala) may be responsible for this work.
>  #Finally, the patch should be approved by akpm and linus, of course...
>
> Matt or Kumar, would you merge BOOKE_WDT patch to 2.6 kernel tree?
>  IIRC, This patch has been left under review state about two month.
>  Is there something to be needed for the patch?

Sorry, I think Matt and I have been busy with normal "work".  I'll take 
a look at this in the next week.  If you can update the patches to 
something current that would help (but is not critical).

thanks
- kumar

Re: PPC 44x Watchdog timer

[Takeharu KATO]

Hi Kumar:

> 
> 
> Sorry, I think Matt and I have been busy with normal "work".  I'll take 
> a look at this in the next week.  If you can update the patches to 
> something current that would help (but is not critical).
> 
Thank you for your response.
OK,I'll tweaks minor changes for current kernel in linus's git kernel.

[PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Takeharu KATO]

Hi Kumar:

> 
> Sorry, I think Matt and I have been busy with normal "work".  I'll take 
> a look at this in the next week.  If you can update the patches to 
> something current that would help (but is not critical).
> 
I updated the patch to current linus-git kernel(pulled in 2005/05/05 
JST). Please use this for your testing.

This is architecture dependent part.
I'll re-test this patch in the next week.

Signed-off-by: kato.takeharu@jp.fujitsu.com

diff -Nupr linux-2.6.orig/arch/ppc/kernel/head_44x.S 
linux-2.6/arch/ppc/kernel/head_44x.S
--- linux-2.6.orig/arch/ppc/kernel/head_44x.S	2005-05-06 
05:03:55.000000000 +0900
+++ linux-2.6/arch/ppc/kernel/head_44x.S	2005-05-07 05:03:24.000000000 +0900
@@ -448,8 +448,11 @@ interrupt_base:
  	EXCEPTION(0x1010, FixedIntervalTimer, UnknownException, EXC_XFER_EE)

  	/* Watchdog Timer Interrupt */
-	/* TODO: Add watchdog support */
+#if defined(CONFIG_BOOKE_WDT)
+	CRITICAL_EXCEPTION(0x1020, WatchdogTimer, booke_wdt_exception)
+#else
  	CRITICAL_EXCEPTION(0x1020, WatchdogTimer, UnknownException)
+#endif  /*  CONFIG_BOOKE_WDT  */

  	/* Data TLB Error Interrupt */
  	START_EXCEPTION(DataTLBError)
diff -Nupr linux-2.6.orig/arch/ppc/kernel/head_4xx.S 
linux-2.6/arch/ppc/kernel/head_4xx.S
--- linux-2.6.orig/arch/ppc/kernel/head_4xx.S	2005-05-06 
05:03:55.000000000 +0900
+++ linux-2.6/arch/ppc/kernel/head_4xx.S	2005-05-07 05:03:24.000000000 +0900
@@ -430,27 +430,24 @@ label:

  /* 0x1000 - Programmable Interval Timer (PIT) Exception */
  	START_EXCEPTION(0x1000, Decrementer)
-	NORMAL_EXCEPTION_PROLOG
-	lis	r0,TSR_PIS@h
-	mtspr	SPRN_TSR,r0		/* Clear the PIT exception */
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_LITE(0x1000, timer_interrupt)
+	b    DecrementerHandler

  #if 0
  /* NOTE:
- * FIT and WDT handlers are not implemented yet.
+ * FIT handler is not implemented yet.
   */

  /* 0x1010 - Fixed Interval Timer (FIT) Exception
  */
  	STND_EXCEPTION(0x1010,	FITException,		UnknownException)

-/* 0x1020 - Watchdog Timer (WDT) Exception
-*/
-
-	CRITICAL_EXCEPTION(0x1020, WDTException, UnknownException)
  #endif

+/* 0x1020 - Watchdog Timer (WDT) Exception
+ */
+	START_EXCEPTION(0x1020, WDTException)
+	b    WatchDogHandler
+
  /* 0x1100 - Data TLB Miss Exception
   * As the name implies, translation is not in the MMU, so search the
   * page tables and fix it.  The only purpose of this function is to
@@ -732,6 +729,13 @@ label:
  		(MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
  		NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)

+DecrementerHandler:
+	NORMAL_EXCEPTION_PROLOG
+	lis    r0,TSR_PIS@h
+	mtspr    SPRN_TSR,r0        /* Clear the PIT exception */
+	addi    r3,r1,STACK_FRAME_OVERHEAD
+	EXC_XFER_LITE(0x1000, timer_interrupt)
+
  /*
   * The other Data TLB exceptions bail out to this point
   * if they can't resolve the lightweight TLB fault.
@@ -804,6 +808,19 @@ finish_tlb_load:
  	PPC405_ERR77_SYNC
  	rfi			/* Should sync shadow TLBs */
  	b	.		/* prevent prefetch past rfi */
+/*
+ * WatchDog Exception
+ */
+WatchDogHandler:
+	CRITICAL_EXCEPTION_PROLOG;
+	addi    r3,r1,STACK_FRAME_OVERHEAD;
+#if defined(CONFIG_BOOKE_WDT)
+	EXC_XFER_TEMPLATE(booke_wdt_exception, 0x1022, (MSR_KERNEL & 
~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY, crit_transfer_to_handler, 
ret_from_crit_exc)
+
+#else
+	EXC_XFER_TEMPLATE(UnknownException, 0x1022, (MSR_KERNEL & 
~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY, crit_transfer_to_handler, 
ret_from_crit_exc)
+#endif  /*  CONFIG_BOOKE_WDT  */
+

  /* extern void giveup_fpu(struct task_struct *prev)
   *
diff -Nupr linux-2.6.orig/arch/ppc/kernel/head_fsl_booke.S 
linux-2.6/arch/ppc/kernel/head_fsl_booke.S
--- linux-2.6.orig/arch/ppc/kernel/head_fsl_booke.S	2005-05-06 
05:03:55.000000000 +0900
+++ linux-2.6/arch/ppc/kernel/head_fsl_booke.S	2005-05-07 
05:05:06.000000000 +0900
@@ -526,8 +526,11 @@ interrupt_base:
  	EXCEPTION(0x3100, FixedIntervalTimer, UnknownException, EXC_XFER_EE)

  	/* Watchdog Timer Interrupt */
-	/* TODO: Add watchdog support */
-	CRITICAL_EXCEPTION(0x3200, WatchdogTimer, UnknownException)
+#if defined(CONFIG_BOOKE_WDT)
+	CRITICAL_EXCEPTION(0x3200, WatchdogTimer, booke_wdt_exception)
+#else
+ 	CRITICAL_EXCEPTION(0x3200, WatchdogTimer, UnknownException)
+#endif  /*  CONFIG_BOOKE_WDT  */

  	/* Data TLB Error Interrupt */
  	START_EXCEPTION(DataTLBError)
diff -Nupr linux-2.6.orig/arch/ppc/platforms/85xx/mpc8540_ads.c 
linux-2.6/arch/ppc/platforms/85xx/mpc8540_ads.c
--- linux-2.6.orig/arch/ppc/platforms/85xx/mpc8540_ads.c	2005-05-06 
05:03:57.000000000 +0900
+++ linux-2.6/arch/ppc/platforms/85xx/mpc8540_ads.c	2005-05-07 
05:08:39.000000000 +0900
@@ -187,6 +187,14 @@ platform_init(unsigned long r3, unsigned
  		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
  	}

+#ifdef CONFIG_BOOKE_WDT
+	{
+	  extern void booke_wdt_setup_options(char *cmd_line);
+
+	  booke_wdt_setup_options(cmd_line);
+	}
+#endif  /*  CONFIG_BOOKE_WDT  */
+
  	identify_ppc_sys_by_id(mfspr(SPRN_SVR));

  	/* setup the PowerPC module struct */
diff -Nupr linux-2.6.orig/arch/ppc/platforms/85xx/mpc8560_ads.c 
linux-2.6/arch/ppc/platforms/85xx/mpc8560_ads.c
--- linux-2.6.orig/arch/ppc/platforms/85xx/mpc8560_ads.c	2005-05-06 
05:03:57.000000000 +0900
+++ linux-2.6/arch/ppc/platforms/85xx/mpc8560_ads.c	2005-05-07 
05:09:12.000000000 +0900
@@ -183,6 +183,14 @@ platform_init(unsigned long r3, unsigned
  		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
  	}

+#ifdef CONFIG_BOOKE_WDT
+      {
+        extern void booke_wdt_setup_options(char *cmd_line);
+
+        booke_wdt_setup_options(cmd_line);
+      }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
  	identify_ppc_sys_by_id(mfspr(SPRN_SVR));

  	/* setup the PowerPC module struct */
diff -Nupr linux-2.6.orig/arch/ppc/platforms/85xx/mpc85xx_cds_common.c 
linux-2.6/arch/ppc/platforms/85xx/mpc85xx_cds_common.c
--- linux-2.6.orig/arch/ppc/platforms/85xx/mpc85xx_cds_common.c 
2005-05-06 05:03:57.000000000 +0900
+++ linux-2.6/arch/ppc/platforms/85xx/mpc85xx_cds_common.c	2005-05-07 
05:07:59.000000000 +0900
@@ -432,6 +432,14 @@ platform_init(unsigned long r3, unsigned
  		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
  	}

+#ifdef CONFIG_BOOKE_WDT
+      {
+        extern void booke_wdt_setup_options(char *cmd_line);
+
+        booke_wdt_setup_options(cmd_line);
+      }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
  	identify_ppc_sys_by_id(mfspr(SPRN_SVR));

  	/* setup the PowerPC module struct */
diff -Nupr linux-2.6.orig/arch/ppc/platforms/85xx/sbc8560.c 
linux-2.6/arch/ppc/platforms/85xx/sbc8560.c
--- linux-2.6.orig/arch/ppc/platforms/85xx/sbc8560.c	2005-05-06 
05:03:57.000000000 +0900
+++ linux-2.6/arch/ppc/platforms/85xx/sbc8560.c	2005-05-07 
05:06:59.000000000 +0900
@@ -198,6 +198,14 @@ platform_init(unsigned long r3, unsigned
  		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
  	}

+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
  	identify_ppc_sys_by_id(mfspr(SPRN_SVR));

  	/* setup the PowerPC module struct */
diff -Nupr linux-2.6.orig/arch/ppc/platforms/85xx/stx_gp3.c 
linux-2.6/arch/ppc/platforms/85xx/stx_gp3.c
--- linux-2.6.orig/arch/ppc/platforms/85xx/stx_gp3.c	2005-05-06 
05:03:57.000000000 +0900
+++ linux-2.6/arch/ppc/platforms/85xx/stx_gp3.c	2005-05-07 
05:10:12.000000000 +0900
@@ -331,6 +331,14 @@ platform_init(unsigned long r3, unsigned
  		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
  	}

+#ifdef CONFIG_BOOKE_WDT
+      {
+        extern void booke_wdt_setup_options(char *cmd_line);
+
+        booke_wdt_setup_options(cmd_line);
+      }
+#endif  /*  CONFIG_BOOKE_WDT  */
+
  	identify_ppc_sys_by_id(mfspr(SPRN_SVR));

  	/* setup the PowerPC module struct */
diff -Nupr linux-2.6.orig/arch/ppc/syslib/ppc4xx_setup.c 
linux-2.6/arch/ppc/syslib/ppc4xx_setup.c
--- linux-2.6.orig/arch/ppc/syslib/ppc4xx_setup.c	2005-05-06 
05:03:58.000000000 +0900
+++ linux-2.6/arch/ppc/syslib/ppc4xx_setup.c	2005-05-07 
05:03:25.000000000 +0900
@@ -48,10 +48,6 @@
  extern void abort(void);
  extern void ppc4xx_find_bridges(void);

-extern void ppc4xx_wdt_heartbeat(void);
-extern int wdt_enable;
-extern unsigned long wdt_period;
-
  /* Global Variables */
  bd_t __res;

@@ -257,22 +253,14 @@ ppc4xx_init(unsigned long r3, unsigned l
  		*(char *) (r7 + KERNELBASE) = 0;
  		strcpy(cmd_line, (char *) (r6 + KERNELBASE));
  	}
-#if defined(CONFIG_PPC405_WDT)
-/* Look for wdt= option on command line */
-	if (strstr(cmd_line, "wdt=")) {
-		int valid_wdt = 0;
-		char *p, *q;
-		for (q = cmd_line; (p = strstr(q, "wdt=")) != 0;) {
-			q = p + 4;
-			if (p > cmd_line && p[-1] != ' ')
-				continue;
-			wdt_period = simple_strtoul(q, &q, 0);
-			valid_wdt = 1;
-			++q;
-		}
-		wdt_enable = valid_wdt;
-	}
-#endif
+
+#ifdef CONFIG_BOOKE_WDT
+     {
+       extern void booke_wdt_setup_options(char *cmd_line);
+
+       booke_wdt_setup_options(cmd_line);
+     }
+#endif  /*  CONFIG_BOOKE_WDT  */

  	/* Initialize machine-dependent vectors */

[PATCH] BOOKE_WDT Part 2/2 (Re: PPC 44x Watchdog timer)

[Takeharu KATO]

Hi Kumar:

 >
 > Sorry, I think Matt and I have been busy with normal "work".  I'll take
 > a look at this in the next week.  If you can update the patches to
 > something current that would help (but is not critical).
 >
This is device driver part.

Signed-off-by: kato.takeharu@jp.fujitsu.com


diff -Nupr linux-2.6.orig/drivers/char/watchdog/Kconfig 
linux-2.6/drivers/char/watchdog/Kconfig
--- linux-2.6.orig/drivers/char/watchdog/Kconfig	2005-05-06 
05:04:23.000000000 +0900
+++ linux-2.6/drivers/char/watchdog/Kconfig	2005-05-07 
05:17:03.000000000 +0900
@@ -346,6 +346,13 @@ config 8xx_WDT
  	tristate "MPC8xx Watchdog Timer"
  	depends on WATCHDOG && 8xx

+config BOOKE_WDT
+    bool "Book E(PowerPC 4xx/e500) Watchdog Timer"
+    depends on WATCHDOG && ( 4xx || E500 )
+    ---help---
+      This is the driver for the watchdog timers on
+      PowerPC 4xx and PowerPC e500.
+
  # MIPS Architecture

  config INDYDOG
diff -Nupr linux-2.6.orig/drivers/char/watchdog/Makefile 
linux-2.6/drivers/char/watchdog/Makefile
--- linux-2.6.orig/drivers/char/watchdog/Makefile	2005-05-06 
05:04:23.000000000 +0900
+++ linux-2.6/drivers/char/watchdog/Makefile	2005-05-07 
05:17:34.000000000 +0900
@@ -33,6 +33,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.
  obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
  obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o
  obj-$(CONFIG_8xx_WDT) += mpc8xx_wdt.o
+obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o

  # Only one watchdog can succeed. We probe the hardware watchdog
  # drivers first, then the softdog driver.  This means if your hardware
diff -Nupr linux-2.6.orig/drivers/char/watchdog/booke_wdt.c 
linux-2.6/drivers/char/watchdog/booke_wdt.c
--- linux-2.6.orig/drivers/char/watchdog/booke_wdt.c	1970-01-01 
09:00:00.000000000 +0900
+++ linux-2.6/drivers/char/watchdog/booke_wdt.c	2005-05-07 
05:19:17.000000000 +0900
@@ -0,0 +1,629 @@
+/*
+ *    Copyright (c) 2005 Fujitsu Limited
+ *
+ *    Module name: booke_wdt.c
+ *    Author:      Takeharu KATO<kato.takeharu@jp.fujitsu.com>
+ *
+ *    This program is free software; you can redistribute it and/or
+ *    modify it under the terms of the GNU General Public License
+ *    as published by the Free Software Foundation; either version 2
+ *    of the License, or (at your option) any later version.
+ *
+ *    Neither Takeharu KATO nor Fujitsu Ltd. admit liability nor provide
+ *    warranty for any of this software.
+ *
+ *    Description:
+ *     Watchdog driver for PowerPC Book E (PowerPC 4xx series 
processors and
+ *     PowerPC e500 series processors).
+ *     Derived from drivers/char/watchdog/wdt.c by Alan cox
+ *              and  drivers/char/watchdog/ppc405_wdt.c by Armin Kuster.
+ *     PPC4xx WDT operation is driverd from Appendix of
+ *     PowerPC Embedded Processors Application Note
+ *      ``PowerPC 40x Watch Dog Timer'' published from IBM.
+ *     This driver is written according to ``PowerPC e500 Core Complex
+ *     Reference Manual'' for e500 part.
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/capability.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <asm/reg.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/cputable.h>
+#include "booke_wdt.h"
+
+/* micro seconds per one milli-second(used to calculatewatchdog
+ * counter to be set). */
+#define US_PER_MS 1000
+/*  Calculate watchdog count   */
+#define calculate_wdt_count(t) ((((unsigned long)(t))*HZ)/1000)
+
+int wdt_enable=0;             /* WDT start on boot  */
+int wdt_period=WDT_TIMO;       /* Time out in ms */
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+/*
+ * Global variables
+ */
+static int wdt_count = 0;            /* WDT intrrupt counter to be 
reloaded */
+static volatile int wdt_heartbeat_count = 0;  /* WDT intrrupt 
counter(compatible mode)*/
+static unsigned long driver_state; /* Driver status (see: booke_wdt.h) */
+/*
+ *  Identifier for this watchdog
+ */
+static struct watchdog_info ident = {
+  .options=WDIOF_SETTIMEOUT|WDIOF_KEEPALIVEPING|WDIOF_MAGICCLOSE,
+  .firmware_version =    0, /*  This is filled with PVR in 
initialization. */
+  .identity =        "Book E(PPC 4xx/e500) WDT",
+};
+
+/*
+ *  PowerPC Linux common exception handler
+ */
+extern void _exception(int signr, struct pt_regs *regs, int code, 
unsigned long addr);
+/*  Panic notifier  */
+extern struct notifier_block *panic_notifier_list;
+/*
+ *    Watchdog operations on PPC4xx/e500 MPU
+ */
+/**
+ *      __booke_wdt_setup_val
+ *      Enable Watchdog, sets up passed in values for TCR[WP],
+ *      TCR[WRC]
+ *
+ *    @period:    Input Watchdog Period - TCR[WP]
+ *                      0...2^17(PPC405) or 2^21(PPC440/e500) clocks
+ *                      1...2^21(PPC405) or 2^25(PPC440/e500) clocks
+ *                      2...2^25(PPC405) or 2^29(PPC440/e500) clocks
+ *                      3...2^25(PPC405) or 2^29(PPC440/e500) clocks
+ *    @reset:         Watchdog reset control - TCR[WRC]
+ *                      0 = No reset
+ *                      1 = PPC Core reset only
+ *                      2 = PPC Chip reset
+ *                      3 = System reset
+ *     Note: The meaning of period number is differ PPC405 from PPC440.
+ *           Current version assume that this function called with
+ *           WRC_NONE as reset, if someone who want to remove this
+ *           constraint, please note that when we disable WDT, we should
+ *           set WRC with WRC_NONE and s/he should also  modify
+ *           disable/enable_wdt function.
+ *
+ */
+static __inline__ void
+__booke_wdt_setup_val(int period,int reset)
+{
+  unsigned long val;
+
+  /*  Set up TCR  */
+  val=wdt_calculate_tcr(period,reset)| mfspr(SPRN_TCR);
+  /*  Disable WDT  */
+  val &= ~(TCR_WIE);
+
+  mtspr(SPRN_TCR,val);
+}
+/**
+ *      __booke_wdt_enable
+ *      Enable Watchdog
+ */
+static __inline__ void
+__booke_wdt_enable(void)
+{
+  mtspr(SPRN_TCR,(mfspr(SPRN_TCR)|TCR_WIE));
+}
+/**
+ *      __booke_wdt_disable
+ *      Disable Watchdog
+ */
+static __inline__ void
+__booke_wdt_disable(void)
+{
+  mtspr(SPRN_TCR,(mfspr(SPRN_TCR)&(~(TCR_WIE))));
+}
+/**
+ *      __booke_wdt_is_enabled
+ *      Check whether Watchdog is enabled.
+ */
+static __inline__ int
+__booke_wdt_is_enabled(void)
+{
+  return (mfspr(SPRN_TCR) & TCR_WIE);
+}
+/**
+ *      __booke_wdt_clear_init_stat
+ *      Clear interrupt status of watchdog to ping it.
+ */
+static __inline__ void
+__booke_wdt_clear_int_stat(void)
+{
+  mtspr(SPRN_TSR, (TSR_ENW|TSR_WIS));
+}
+/**
+ *    __booke_wdt_set_timeout:
+ *    @t:    the new time out value that needs to be set.
+ *
+ *    Set a new time out value for the watchdog device.
+ *
+ */
+static __inline__ void
+__booke_wdt_set_timeout(int t)
+{
+  wdt_count=calculate_wdt_count(t);
+  return;
+}
+
+/*
+ * Driver specific functions
+ */
+
+/**
+ *   booke_wdt_setup_options
+ *   @cmd_line : a pointer to kernel command line.
+ *
+ */
+void
+booke_wdt_setup_options(char *cmd_line)
+{
+/*
+ * Look for wdt= option on command line
+ */
+  if (strstr(cmd_line, "wdt=")) {
+    int valid_wdt = 0;
+    char *p, *q;
+
+    for (q = cmd_line; (p = strstr(q, "wdt=")) != 0;) {
+      q = p + 4;
+      if (p > cmd_line && p[-1] != ' ')
+    continue;
+      wdt_period = simple_strtoul(q, &q, 0);
+      valid_wdt = 1;
+      ++q;
+    }
+    wdt_enable = valid_wdt;
+  }
+  return;
+}
+/**
+ *    booke_wdt_heartbeat:
+ *      Ping routine called from kernel.
+ */
+void
+booke_wdt_heartbeat(void)
+{
+  /* Disable watchdog */
+  __booke_wdt_disable();
+
+  /* Write a watchdog value */
+  __booke_wdt_clear_int_stat();
+
+  if (!wdt_enable)
+    goto out;
+
+  if  (wdt_heartbeat_count > 0)
+    wdt_heartbeat_count--;
+  else
+    panic(booke_mkmsg("Initiating system reboot.\n"));
+
+  /* Enable watchdog */
+  __booke_wdt_enable();
+ out:
+  /*  Reset count  */
+  ppc_md.heartbeat_count = 0;
+}
+/**
+ *    booke_wdt_exception:
+ *      WatchDog Exception handler for PPC4xx/e500.
+ *      @regs : A registers information.
+ */
+void
+booke_wdt_exception(struct pt_regs *regs)
+{
+
+  wdt_enable=0;
+  __booke_wdt_disable();
+  printk(KERN_EMERG "WDT Exception at PC: %lx, MSR: %lx, vector=%lx 
%s\n",
+     regs->nip, regs->msr, regs->trap, print_tainted());
+  panic(booke_mkmsg("Initiating system reboot.\n"));
+}
+/*
+ *    Driver Logic functions
+ */
+static __inline__ int
+booke_wdt_is_enabled(void)
+{
+  return  __booke_wdt_is_enabled();
+}
+/**
+ *    booke_wdt_start:
+ *
+ *    Start the watchdog driver.
+ */
+static __inline__ int
+booke_wdt_start(void)
+{
+
+  __booke_wdt_enable();
+  return 0;
+}
+
+/**
+ *    booke_wdt_stop:
+ *
+ *    Stop the watchdog driver.
+ */
+static __inline__ int
+booke_wdt_stop (void)
+{
+
+  __booke_wdt_disable();
+  return 0;
+}
+/**
+ *    booke_wdt_ping:
+ *
+ *    Reload counter one with the watchdog heartbeat. We don't bother 
reloading
+ *    the cascade counter.
+ */
+static __inline__ int
+booke_wdt_ping(void)
+{
+
+  /* Disable watchdog */
+  __booke_wdt_disable();
+  /* Write a watchdog value */
+  __booke_wdt_clear_int_stat();
+  /*  Reset count  */
+  wdt_heartbeat_count=wdt_count;
+  /* Enable watchdog */
+  __booke_wdt_enable();
+
+  return 0;
+}
+/**
+ *    booke_wdt_set_timeout:
+ *    @t:        the new timeout value that needs to be set.
+ *
+ *    Set a new time out value for the watchdog device.
+ *      If the heartbeat value is incorrect we keep the old value
+ *      and return -EINVAL. If successfull we return 0.
+ */
+static __inline__ int
+booke_wdt_set_timeout(int t)
+{
+
+  if ((t < WDT_HEARTBEAT_MIN) || (t > WDT_HEARTBEAT_MAX))
+    return -EINVAL;
+
+  wdt_period = t;
+  __booke_wdt_set_timeout(t);
+  wdt_heartbeat_count=wdt_count;
+  booke_wdt_dbg("The WDT counter set %d.\n",wdt_count);
+
+  return 0;
+}
+
+/**
+ *    booke_wdt_get_status:
+ *    @status: the new status.
+ *
+ *    Return the enable/disable card status.
+ */
+static __inline__ int
+booke_wdt_get_status(int *status)
+{
+
+  if (wdt_enable)
+      *status = WDIOS_ENABLECARD;
+  else
+      *status = WDIOS_DISABLECARD;
+
+  return 0;
+}
+/*
+ *    Kernel Interfaces
+ */
+/**
+ *    booke_wdt_init_device:
+ *
+ *      Initilize PowerPC 4xx/e500 family Watch Dog facility.
+ */
+static void
+booke_wdt_init_device(void)
+{
+
+    /* Hardware WDT provided by the processor.
+     * So, we set firmware version as processor version number.
+     */
+    ident.firmware_version=cpu_specs[0].pvr_value;
+    __booke_wdt_setup_val(WDT_WP,WRC_NONE);
+}
+/**
+ *    booke_wdt_write:
+ *    @file: file handle to the watchdog
+ *    @buf: buffer to write (unused as data does not matter here
+ *    @count: count of bytes
+ *    @ppos: pointer to the position to write. No seeks allowed
+ *
+ *    A write to a watchdog device is defined as a keepalive signal. Any
+ *    write of data will do, as we we don't define content meaning expept
+ *      'V' character. It is performed as a sign to set stop-on-close mode.
+ */
+
+static ssize_t
+booke_wdt_write(struct file *file, const char *buf, size_t count, 
loff_t *ppos)
+{
+  size_t i;
+
+  if (!nowayout) {
+    /* In case it was set long ago */
+    clear_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+
+    for (i = 0; i < count; i++) {
+      char c;
+
+      if (get_user(c, buf + i))
+	return -EFAULT;
+
+      if (c == 'V') {
+	set_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+      }
+    }
+  }
+  booke_wdt_ping();
+
+  return count;
+}
+
+/**
+ *    booke_wdt_ioctl:
+ *    @inode: inode of the device
+ *    @file: file handle to the device
+ *    @cmd: watchdog command
+ *    @arg: argument pointer
+ *
+ */
+static int
+booke_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+    unsigned long arg)
+{
+    int new_timeout;
+    int status;
+
+    if (!capable(CAP_SYS_ADMIN))
+        return -EPERM;  /*  It may be too strict manner.  */
+    switch(cmd)
+    {
+    default:
+        return -ENOIOCTLCMD;
+    case WDIOC_GETSUPPORT:
+        if (copy_to_user((struct watchdog_info *)arg, &ident, 
sizeof(struct watchdog_info)))
+            return -EFAULT;
+        else
+            break;
+    case WDIOC_GETSTATUS:
+        booke_wdt_get_status(&status);
+        return put_user(status,(int *)arg);
+    case WDIOC_KEEPALIVE:
+        booke_wdt_ping();
+        break;
+    case WDIOC_SETTIMEOUT:
+        if (get_user(new_timeout, (int *)arg))
+            return -EFAULT;
+        if (booke_wdt_set_timeout(new_timeout))
+            return -EINVAL;
+        booke_wdt_ping();
+        break;
+    case WDIOC_GETTIMEOUT:
+        return put_user(wdt_period, (int *)arg);
+    case WDIOC_SETOPTIONS:
+        if (get_user(status, (int *)arg))
+            return -EFAULT;
+        /*  Return -EINVAL when the driver can not figure out
+         *  what it should do. Unknown cases are just ignored.
+         */
+        if ( (status & (WDIOS_DISABLECARD|WDIOS_ENABLECARD))
+             == (WDIOS_DISABLECARD|WDIOS_ENABLECARD) )
+            return -EINVAL;
+        if (status & WDIOS_DISABLECARD) {
+            wdt_enable = 0;
+            booke_wdt_stop();
+            booke_wdt_info("Watchdog timer is disabled\n");
+        }
+        if (status & WDIOS_ENABLECARD) {
+            wdt_enable = 1;
+            booke_wdt_start();
+            booke_wdt_info("Watchdog timer is enabled\n");
+        }
+        break;
+    }
+    return 0;
+}
+/**
+ *    booke_wdt_open:
+ *    @inode: inode of device
+ *    @file: file handle to device
+ *
+ *    The watchdog device has been opened. The watchdog device is single
+ *    open and start the WDT timer.
+ */
+static int
+booke_wdt_open(struct inode *inode, struct file *file)
+{
+    if (!capable(CAP_SYS_ADMIN))
+        return -EPERM;
+
+    if (test_and_set_bit(WDT_STATE_OPEN, &driver_state))
+        return -EBUSY;
+    /*
+     * Activate
+     */
+    booke_wdt_start();
+    wdt_enable=1;
+
+    if (nowayout)
+      set_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state);
+
+    return 0;
+}
+
+/**
+ *    booke_wdt_release:
+ *    @inode: inode to board
+ *    @file: file handle to board
+ *
+ */
+static int
+booke_wdt_release(struct inode *inode, struct file *file)
+{
+  if (test_bit(WDT_STATE_STOP_ON_CLOSE, &driver_state)) {
+      booke_wdt_info("WDT device is stopped.\n");
+    booke_wdt_stop();
+    wdt_enable=0;
+  } else {
+    if ( (booke_wdt_is_enabled()) && (!nowayout) ) {
+      booke_wdt_info("WDT device may be closed unexpectedly.  WDT will 
not stop!\n");
+      booke_wdt_ping();
+    }
+  }
+  clear_bit(WDT_STATE_OPEN, &driver_state);
+
+  return 0;
+}
+/**
+ *    notify_sys:
+ *    @this: our notifier block
+ *    @code: the event being reported
+ *    @unused: unused
+ *    Note: This function assume that the panic notifier is called with 
CODE=0
+ *          (see panic function in kernel/panic.c).
+ */
+static int
+booke_wdt_notify_sys(struct notifier_block *this, unsigned long code,
+    void *unused)
+{
+
+    if (code != SYS_POWER_OFF)   /* Turn the card off */
+      booke_wdt_stop();
+
+    return NOTIFY_DONE;
+}
+
+static struct file_operations booke_wdt_fops = {
+    .owner        = THIS_MODULE,
+    .llseek        = no_llseek,
+    .write        = booke_wdt_write,
+    .ioctl        = booke_wdt_ioctl,
+    .open        = booke_wdt_open,
+    .release    = booke_wdt_release,
+};
+
+static struct miscdevice booke_wdt_miscdev = {
+    .minor    = WATCHDOG_MINOR,
+    .name    = "watchdog",
+    .fops    = &booke_wdt_fops,
+};
+
+/*
+ *    The WDT card needs to know about shutdowns in order to
+ *    turn WDT off.
+ */
+
+static struct notifier_block booke_wdt_notifier = {
+    .notifier_call = booke_wdt_notify_sys,
+};
+
+/**
+ *    cleanup_module:
+ *
+ *    If your watchdog is set to continue ticking on close and you unload
+ *    it, well it keeps ticking.  You just have to load a new
+ *    module in 60 seconds or reboot.
+ *      This behavior(more over the comments as above) is borrowed from
+ *      Alan cox's driver.
+ */
+
+static void __exit
+booke_wdt_exit(void)
+{
+    misc_deregister(&booke_wdt_miscdev);
+    unregister_reboot_notifier(&booke_wdt_notifier);
+    notifier_chain_unregister(&panic_notifier_list,&booke_wdt_notifier);
+}
+
+/**
+ *     booke_wdt_init:
+ *
+ *    Set up the WDT relevant timer facility.
+ */
+
+static int __init
+booke_wdt_init(void)
+{
+    int ret;
+    unsigned long flags;
+
+    ret = register_reboot_notifier(&booke_wdt_notifier);
+    if(ret) {
+      booke_wdt_err("Cannot register reboot notifier (err=%d)\n", ret);
+      return ret;
+    }
+
+    /* Register panic notifier  */
+    ret = 
notifier_chain_register(&panic_notifier_list,&booke_wdt_notifier);
+    if(ret) {
+      booke_wdt_err("Cannot register panic notifier (err=%d)\n", ret);
+      unregister_reboot_notifier(&booke_wdt_notifier);
+      return ret;
+    }
+
+    ret = 0;
+    booke_wdt_init_device();
+    /* Check that the heartbeat value is within it's range ; if not 
reset to the default */
+    if (booke_wdt_set_timeout(wdt_period)) {
+      if (wdt_period)
+        booke_wdt_info("The heartbeat value must be %d < wdt_period < 
%d, using %d\n",WDT_HEARTBEAT_MIN,WDT_HEARTBEAT_MAX,WDT_TIMO);
+      booke_wdt_set_timeout(WDT_TIMO);
+    }
+
+    local_irq_save(flags); /* Prevent timer interrupt */
+    ppc_md.heartbeat_count = 0;
+    ppc_md.heartbeat=booke_wdt_heartbeat;
+    local_irq_restore(flags);
+
+    booke_wdt_info("Book E(PPC 4xx/e500) Watchdog Driver. period=%d ms 
(nowayout=%d)\n",wdt_period, nowayout);
+
+    ret = misc_register(&booke_wdt_miscdev);
+    if (ret) {
+      booke_wdt_err("Cannot register miscdev on minor=%d (err=%d)\n",
+            WATCHDOG_MINOR, ret);
+        goto outmisc;
+    }
+
+    if (wdt_enable) {
+      booke_wdt_info("WDT start on boot.\n");
+      booke_wdt_start();
+    }
+out:
+    return ret;
+outmisc:
+    unregister_reboot_notifier(&booke_wdt_notifier);
+    local_irq_save(flags);
+    ppc_md.heartbeat=NULL;
+    ppc_md.heartbeat_count = 0;
+    local_irq_restore(flags);
+    goto out;
+}
+
+device_initcall(booke_wdt_init);
diff -Nupr linux-2.6.orig/drivers/char/watchdog/booke_wdt.h 
linux-2.6/drivers/char/watchdog/booke_wdt.h
--- linux-2.6.orig/drivers/char/watchdog/booke_wdt.h	1970-01-01 
09:00:00.000000000 +0900
+++ linux-2.6/drivers/char/watchdog/booke_wdt.h	2005-05-07 
05:17:03.000000000 +0900
@@ -0,0 +1,110 @@
+/*
+ *
+ *    Copyright (c) 2004 Fujitsu Limited
+ *
+ *    Module name: booke_wdt.h
+ *    Author:      Takeharu KATO<kato.takeharu@jp.fujitsu.com>
+ *    Description:
+ *      Header file for PowerPC Book E(PPC 4xx/e500) watchdog driver.
+ *
+ *    This program is free software; you can redistribute it and/or
+ *    modify it under the terms of the GNU General Public License
+ *    as published by the Free Software Foundation; either version 2
+ *    of the License, or (at your option) any later version.
+ *
+ *    Neither Takeharu KATO nor Fujitsu Ltd. admit liability nor provide
+ *    warranty for any of this software.
+ *
+ */
+#ifndef _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H
+#define _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/watchdog.h>
+#include <asm/reg_booke.h>
+
+/*
+ *  Driver state flags(bit position)
+ */
+#define WDT_STATE_OPEN                  0   /* driver is opend  */
+#define WDT_STATE_STOP_ON_CLOSE         1   /* Stop with close is 
expected */
+/*
+ * Configurations
+ */
+#define WDT_TIMO           60000    /* Default timeout = 60000 ms(1min) */
+#define WDT_HEARTBEAT_MIN  100      /* Minimum timeout = 100 ms */
+#define WDT_HEARTBEAT_MAX  600000   /* Maximum timeout = 600000ms(1hour) */
+#ifdef __KERNEL__
+//#define BOOKE_WDT_DEBUG                     /*  Debug switch */
+
+/*  Watchdog timer periods can be set on PPC 4xx cpus. */
+#if defined(CONFIG_4xx)
+/*
+ *  For PowerPC 4xx
+ */
+#define WDT_WP0               0
+#define WDT_WP1               1
+#define WDT_WP2               2
+#define WDT_WP3               3
+#define wdt_calculate_tcr(period,reset) ( TCR_WP(period) | TCR_WRC(reset) )
+#else
+#if defined(CONFIG_E500)
+/*
+ *  For e500 CPU
+ *  Actually, e500 can arbitrary periods can be set,
+ *  But this driver uses fix period value as same as PPC440
+ *  on purpose for simplicity.
+ *  Following values split into WP and WP_EXT parts in booke_wdt.c.
+ */
+#define WDT_WP0               21
+#define WDT_WP1               25
+#define WDT_WP2               29
+#define WDT_WP3               33
+#define WDT_TCR_WP_BITLEN      2 /*  2bit length  */
+#define WDT_TCR_WP_BITMSK     ((1<<(WDT_TCR_WP_BITLEN))-1)  /*  mask  */
+#define WDT_TCR_WPEXT_BITMSK  0xf  /*  4bit length  */
+#define WDT_TCR_WPEXT_SHIFT   17
+#define WDT_WPEXT_VAL(period) (((period)>>WDT_TCR_WP_BITLEN)&    \
+			       (WDT_TCR_WPEXT_BITMSK))
+#define wdt_calculate_tcr(period,reset) \
+                         ( TCR_WP((period)&(WDT_TCR_WP_BITMSK))  |\
+			   TCR_WRC((reset))                      |\
+		   ( WDT_WPEXT_VAL(period) << WDT_TCR_WPEXT_SHIFT))
+#else
+#error "Book E WDT detects invalid configuration(Unknown CPU)"
+#endif  /*  CONFIG_E500  */
+#endif  /*  CONFIG_4xx   */
+/*
+ *  WP relevant values used in our driver.
+ *  Note:WDT period must be more than HZ(Timer ticks)
+ */
+#define WDT_WP                 WDT_WP3
+
+/*
+ *  IOCTL commands for comaptiblity for old driver
+ */
+#define WDIOC_GETPERIOD         WDIOC_GETTIMEOUT
+#define WDIOC_SETPERIOD         WDIOC_SETTIMEOUT
+
+/*
+ *  output messages
+ */
+#define __BOOKE_WDT_MSG "BookE-WDT : "
+#define booke_mkmsg(str) __BOOKE_WDT_MSG str
+#define booke_wdt_info(fmt,arg...) \
+    printk(KERN_INFO __BOOKE_WDT_MSG fmt,##arg)
+#define booke_wdt_note(fmt,arg...) \
+    printk(KERN_NOTICE __BOOKE_WDT_MSG fmt,##arg)
+#define booke_wdt_err(fmt,arg...) \
+    printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
+#if defined(BOOKE_WDT_DEBUG)
+#define booke_wdt_dbg(fmt,arg...) \
+    printk(KERN_ALERT __BOOKE_WDT_MSG fmt,##arg)
+#else
+#define booke_wdt_dbg(fmt,arg...) \
+        do{}while(0)
+#endif  /*  WDT_DEBUG  */
+
+#endif  /* __KERNEL__  */
+#endif  /*  _DRIVERS_CHAR_WATCHDOG_BOOKE_WDT_H  */

Re: [PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Kumar Gala]

> diff -Nupr linux-2.6.orig/arch/ppc/kernel/head_4xx.S
>  linux-2.6/arch/ppc/kernel/head_4xx.S
> --- linux-2.6.orig/arch/ppc/kernel/head_4xx.S=A0=A0 2005-05-06
> 05:03:55.000000000 +0900
>  +++ linux-2.6/arch/ppc/kernel/head_4xx.S=A0=A0=A0=A0=A0=A0=A0 =
2005-05-07=20
> 05:03:24.000000000 +0900
>  @@ -430,27 +430,24 @@ label:
>

Any reason you moved this code into DecrementerHandler?

> =A0 /* 0x1000 - Programmable Interval Timer (PIT) Exception */
>  =A0 =A0=A0=A0=A0=A0 START_EXCEPTION(0x1000, Decrementer)
>  -=A0=A0=A0=A0=A0=A0 NORMAL_EXCEPTION_PROLOG
> -=A0=A0=A0=A0=A0=A0 lis=A0=A0=A0=A0 r0,TSR_PIS@h
> -=A0=A0=A0=A0=A0=A0 mtspr=A0=A0 SPRN_TSR,r0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=
=A0 /* Clear the PIT exception */
>  -=A0=A0=A0=A0=A0=A0 addi=A0=A0=A0 r3,r1,STACK_FRAME_OVERHEAD
> -=A0=A0=A0=A0=A0=A0 EXC_XFER_LITE(0x1000, timer_interrupt)
> +=A0=A0=A0=A0=A0=A0 b=A0=A0=A0 DecrementerHandler
>
> =A0 #if 0
>  =A0 /* NOTE:
>  - * FIT and WDT handlers are not implemented yet.
>  + * FIT handler is not implemented yet.
>  =A0=A0 */
>
> =A0 /* 0x1010 - Fixed Interval Timer (FIT) Exception
>  =A0 */
>  =A0 =A0=A0=A0=A0=A0 STND_EXCEPTION(0x1010,=A0 FITException,=A0=A0 =
=A0=A0=A0=A0=A0=A0=A0=20
> UnknownException)
>
> -/* 0x1020 - Watchdog Timer (WDT) Exception
>  -*/
>  -
>  -=A0=A0=A0=A0=A0=A0 CRITICAL_EXCEPTION(0x1020, WDTException, =
UnknownException)
> =A0 #endif
>
> +/* 0x1020 - Watchdog Timer (WDT) Exception
>  + */
>  +=A0=A0=A0=A0=A0=A0 START_EXCEPTION(0x1020, WDTException)
> +=A0=A0=A0=A0=A0=A0 b=A0=A0=A0 WatchDogHandler
> +
>  =A0 /* 0x1100 - Data TLB Miss Exception
>  =A0=A0 * As the name implies, translation is not in the MMU, so =
search the
>  =A0=A0 * page tables and fix it.=A0 The only purpose of this function =
is to
>  @@ -732,6 +729,13 @@ label:
>  =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 (MSR_KERNEL & =
~(MSR_ME|MSR_DE|MSR_CE)), \
>  =A0 =A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 NOCOPY, =
crit_transfer_to_handler, ret_from_crit_exc)
>
> +DecrementerHandler:
> +=A0=A0=A0=A0=A0=A0 NORMAL_EXCEPTION_PROLOG
> +=A0=A0=A0=A0=A0=A0 lis=A0=A0=A0 r0,TSR_PIS@h
> +=A0=A0=A0=A0=A0=A0 mtspr=A0=A0=A0 SPRN_TSR,r0=A0=A0=A0=A0=A0=A0=A0 /* =
Clear the PIT exception */
>  +=A0=A0=A0=A0=A0=A0 addi=A0=A0=A0 r3,r1,STACK_FRAME_OVERHEAD
> +=A0=A0=A0=A0=A0=A0 EXC_XFER_LITE(0x1000, timer_interrupt)
> +
>  =A0 /*
>  =A0=A0 * The other Data TLB exceptions bail out to this point
>  =A0=A0 * if they can't resolve the lightweight TLB fault.
>  @@ -804,6 +808,19 @@ finish_tlb_load:
> =A0 =A0=A0=A0=A0=A0 PPC405_ERR77_SYNC
> =A0 =A0=A0=A0=A0=A0 rfi=A0=A0=A0=A0 =A0=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=A0=
=A0=A0 /* Should sync shadow TLBs */
>  =A0 =A0=A0=A0=A0=A0 b=A0=A0=A0=A0=A0=A0 .=A0=A0=A0=A0=A0=A0 =A0=A0=A0=A0=
=A0=A0=A0 /* prevent prefetch past rfi */
>  +/*
>  + * WatchDog Exception
>  + */
>  +WatchDogHandler:
> +=A0=A0=A0=A0=A0=A0 CRITICAL_EXCEPTION_PROLOG;
> +=A0=A0=A0=A0=A0=A0 addi=A0=A0=A0 r3,r1,STACK_FRAME_OVERHEAD;
> +#if defined(CONFIG_BOOKE_WDT)
> +=A0=A0=A0=A0=A0=A0 EXC_XFER_TEMPLATE(booke_wdt_exception, 0x1022, =
(MSR_KERNEL &
> ~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY, crit_transfer_to_handler,
>  ret_from_crit_exc)
> +
>  +#else
>  +=A0=A0=A0=A0=A0=A0 EXC_XFER_TEMPLATE(UnknownException, 0x1022, =
(MSR_KERNEL &
> ~(MSR_ME|MSR_DE|MSR_CE)),NOCOPY, crit_transfer_to_handler,
>  ret_from_crit_exc)
> +#endif=A0 /*=A0 CONFIG_BOOKE_WDT=A0 */
>  +
>
> =A0 /* extern void giveup_fpu(struct task_struct *prev)
>  =A0=A0 *

Re: [PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Takeharu KATO]

Hi Kumar:

I'm sorry that the reply becomes slow.

Kumar Gala wrote:
>>
> 
> Any reason you moved this code into DecrementerHandler?
> 
>>   /* 0x1000 - Programmable Interval Timer (PIT) Exception */
>>          START_EXCEPTION(0x1000, Decrementer)
>>  -       NORMAL_EXCEPTION_PROLOG
>> -       lis     r0,TSR_PIS@h
>> -       mtspr   SPRN_TSR,r0             /* Clear the PIT exception */
>>  -       addi    r3,r1,STACK_FRAME_OVERHEAD
>> -       EXC_XFER_LITE(0x1000, timer_interrupt)
>> +       b    DecrementerHandler
>>
Current PIT exception handler is too big.
If it is not moved, compilation is failed with relocation error.
Because current PIT handler overwrites WDT handler's codes, the compiler 
can not relocate PIT and WDT handler correctly.

Re: [PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Kumar Gala]

No problem, can you replace all the cmd line parsing with early_param()=20=

code in arch/ppc/kernel/setup.c.  Take a look at=20
arch/ppc64/kernel/setup.c for an example.  We still need to add a call=20=

to parse_early_param() in setup_arch().

Matt & I need to talk about the driver patch.  Once I have more=20
feedback on that I'll let you know.  The major issue I have is having=20
the interrupt handler in drivers/char/watchdog/.. instead of=20
arch/ppc/kernel/traps.c.  However, I dont have a good idea how to=20
structure the changes.

- kumar

On May 16, 2005, at 1:57 AM, Takeharu KATO wrote:

> Hi Kumar:
>
> I'm sorry that the reply becomes slow.
>
> Kumar Gala wrote:
>  >>
>  >
> > Any reason you moved this code into DecrementerHandler?
> >
> >>=A0=A0 /* 0x1000 - Programmable Interval Timer (PIT) Exception */
>  >>=A0=A0=A0=A0=A0=A0=A0=A0=A0 START_EXCEPTION(0x1000, Decrementer)
>  >>=A0 -=A0=A0=A0=A0=A0=A0 NORMAL_EXCEPTION_PROLOG
> >> -=A0=A0=A0=A0=A0=A0 lis=A0=A0=A0=A0 r0,TSR_PIS@h
> >> -=A0=A0=A0=A0=A0=A0 mtspr=A0=A0 SPRN_TSR,r0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0 /* Clear the PIT exception=20
> */
>  >>=A0 -=A0=A0=A0=A0=A0=A0 addi=A0=A0=A0 r3,r1,STACK_FRAME_OVERHEAD
> >> -=A0=A0=A0=A0=A0=A0 EXC_XFER_LITE(0x1000, timer_interrupt)
> >> +=A0=A0=A0=A0=A0=A0 b=A0=A0=A0 DecrementerHandler
> >>
>  Current PIT exception handler is too big.
>  If it is not moved, compilation is failed with relocation error.
>  Because current PIT handler overwrites WDT handler's codes, the=20
> compiler
> can not relocate PIT and WDT handler correctly.

Re: [PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Takeharu KATO]

Hi Kumar:

Kumar Gala wrote:
> No problem, can you replace all the cmd line parsing with early_param() 
> code in arch/ppc/kernel/setup.c.  Take a look at 
> arch/ppc64/kernel/setup.c for an example.  We still need to add a call 
> to parse_early_param() in setup_arch().
>
Sorry, I can not figure out what you want.
As far as I look the source tree,arch/ppc/kernel/setup.c does not have 
the function called early_param.
Would you give me a more precise explanation?

> Matt & I need to talk about the driver patch.  Once I have more feedback 
> on that I'll let you know.  The major issue I have is having the 
> interrupt handler in drivers/char/watchdog/.. instead of 
> arch/ppc/kernel/traps.c.  However, I dont have a good idea how to 
> structure the changes.
>

Certainly, moving the interrupt handler from 
drivers/char/watchdog/booke_wdt.c to arch/ppc/kernel/traps.c
is easy, but I can not tell whether it is good or not.

But the handler is not used by the core kernel.
 From this point of view, the handler should not be placed
in arch/ppc/kernel/traps.c. This is the reason why I locate
the exception handler in the driver part.

Anyway, I'll try to move this handler into arch/ppc/kernel/traps.c
for the moment.

Re: [PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Takeharu KATO]

Hi Kumar:

>> No problem, can you replace all the cmd line parsing with 
>> early_param() code in arch/ppc/kernel/setup.c.  Take a look at 
>> arch/ppc64/kernel/setup.c for an example.  We still need to add a call 
>> to parse_early_param() in setup_arch().
>>
> Sorry, I can not figure out what you want.
> As far as I look the source tree,arch/ppc/kernel/setup.c does not have 
> the function called early_param.
> Would you give me a more precise explanation?
> 
On second thought, I make sense what you said.
You asked me that I make some kind of cleanups, didn't you?
If it is true, I'll try to clean up these setups, but it may be
take the time.

Re: [PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Kumar Gala]

On May 17, 2005, at 9:47 AM, Takeharu KATO wrote:

> Hi Kumar:
>
> >> No problem, can you replace all the cmd line parsing with
> >> early_param() code in arch/ppc/kernel/setup.c.=A0 Take a look at
> >> arch/ppc64/kernel/setup.c for an example.=A0 We still need to add a=20=

> call
> >> to parse_early_param() in setup_arch().
>  >>
>  > Sorry, I can not figure out what you want.
> > As far as I look the source tree,arch/ppc/kernel/setup.c does not=20
> have
>  > the function called early_param.
>  > Would you give me a more precise explanation?
>  >
> On second thought, I make sense what you said.
> You asked me that I make some kind of cleanups, didn't you?
>  If it is true, I'll try to clean up these setups, but it may be
>  take the time.

Yes, I think with these changes to us early_param() for command line=20
parsing in a single place will make the first patch look good.

I'm still not sure what suggestions I have for the second patch, I was=20=

more just letting you know my thinking about the fact that it concerned=20=

me that the exception handler code was not in arch/ppc/kernel.  Not to=20=

say this is wrong, it just doesn't feel write.

- kumar

Re: [PATCH] BOOKE_WDT Part 1/2 (Re: PPC 44x Watchdog timer)

[Takeharu KATO]

Hi Kumar:

> 
> Yes, I think with these changes to us early_param() for command line 
> parsing in a single place will make the first patch look good.
>
OK, I'll perform this fix in this week.

> I'm still not sure what suggestions I have for the second patch, I was 
> more just letting you know my thinking about the fact that it concerned 
> me that the exception handler code was not in arch/ppc/kernel.  Not to 
> say this is wrong, it just doesn't feel write.
> 
Hum, I agree this thing, I'll move the WDT exception handler to 
arch/ppc/kernel for the moment.
If someone disagree with this decision in the future, I'll move this 
into driver code again.