Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 47bece87 authored by Thomas Mingarelli's avatar Thomas Mingarelli Committed by Wim Van Sebroeck
Browse files

[WATCHDOG] hpwdt: Add NMI sourcing 



Add NMI sourcing functionality (Can only be active if nmi_watchdog is
inactive).

Signed-off-by: default avatarThomas Mingarelli <thomas.mingarelli@hp.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 55e8ddec

Documentation/watchdog/hpwdt.txt

0 → 100644
+84 −0
Original line number Original line Diff line number Diff line 
Last reviewed: 06/02/2009



                     HP iLO2 NMI Watchdog Driver

              NMI sourcing for iLO2 based ProLiant Servers

                     Documentation and Driver by

              Thomas Mingarelli <thomas.mingarelli@hp.com>



 The HP iLO2 NMI Watchdog driver is a kernel module that provides basic

 watchdog functionality and the added benefit of NMI sourcing. Both the

 watchdog functionality and the NMI sourcing capability need to be enabled

 by the user. Remember that the two modes are not dependant on one another.

 A user can have the NMI sourcing without the watchdog timer and vice-versa.



 Watchdog functionality is enabled like any other common watchdog driver. That

 is, an application needs to be started that kicks off the watchdog timer. A

 basic application exists in the Documentation/watchdog/src directory called

 watchdog-test.c. Simply compile the C file and kick it off. If the system

 gets into a bad state and hangs, the HP ProLiant iLO 2 timer register will

 not be updated in a timely fashion and a hardware system reset (also known as

 an Automatic Server Recovery (ASR)) event will occur.



 The hpwdt driver also has three (3) module parameters. They are the following:



 soft_margin - allows the user to set the watchdog timer value

 allow_kdump - allows the user to save off a kernel dump image after an NMI

 nowayout    - basic watchdog parameter that does not allow the timer to

               be restarted or an impending ASR to be escaped.



 NOTE: More information about watchdog drivers in general, including the ioctl

       interface to /dev/watchdog can be found in

       Documentation/watchdog/watchdog-api.txt and Documentation/IPMI.txt.



 The NMI sourcing capability is disabled when the driver discovers that the

 nmi_watchdog is turned on (nmi_watchdog = 1). This is due to the inability to

 distinguish between "NMI Watchdog Ticks" and "HW generated NMI events" in the

 Linux kernel. What this means is that the hpwdt nmi handler code is called

 each time the NMI signal fires off. This could amount to several thousands of

 NMIs in a matter of seconds. If a user sees the Linux kernel's "dazed and

 confused" message in the logs or if the system gets into a hung state, then

 the user should reboot with nmi_watchdog=0.



 1. If the kernel has not been booted with nmi_watchdog turned off then

    edit /boot/grub/menu.lst and place the nmi_watchdog=0 at the end of the

    currently booting kernel line.

 2. reboot the sever



 Now, the hpwdt can successfully receive and source the NMI and provide a log

 message that details the reason for the NMI (as determined by the HP BIOS).



 Below is a list of NMIs the HP BIOS understands along with the associated

 code (reason):



	No source found                00h



	Uncorrectable Memory Error     01h



	ASR NMI                        1Bh



	PCI Parity Error               20h



	NMI Button Press               27h



	SB_BUS_NMI                     28h



	ILO Doorbell NMI               29h



	ILO IOP NMI                    2Ah



	ILO Watchdog NMI               2Bh



	Proc Throt NMI                 2Ch



	Front Side Bus NMI             2Dh



	PCI Express Error              2Fh



	DMA controller NMI             30h



	Hypertransport/CSI Error       31h







 -- Tom Mingarelli

    (thomas.mingarelli@hp.com)

drivers/watchdog/hpwdt.c

+44 −15
Original line number Original line Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/interrupt.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/io.h>

#include <linux/irq.h>

#include <linux/irq.h>

#include <linux/nmi.h>

#include <linux/kernel.h>

#include <linux/kernel.h>

#include <linux/miscdevice.h>

#include <linux/miscdevice.h>

#include <linux/mm.h>

#include <linux/mm.h>
@@ -47,7 +48,7 @@ 
#define PCI_BIOS32_PARAGRAPH_LEN	16

#define PCI_BIOS32_PARAGRAPH_LEN	16

#define PCI_ROM_BASE1			0x000F0000

#define PCI_ROM_BASE1			0x000F0000

#define ROM_SIZE			0x10000

#define ROM_SIZE			0x10000

#define HPWDT_VERSION			"1.01"

#define HPWDT_VERSION			"1.1.1"





struct bios32_service_dir {

struct bios32_service_dir {

	u32 signature;

	u32 signature;
@@ -119,6 +120,7 @@ static int nowayout = WATCHDOG_NOWAYOUT; 
static char expect_release;

static char expect_release;

static unsigned long hpwdt_is_open;

static unsigned long hpwdt_is_open;

static unsigned int allow_kdump;

static unsigned int allow_kdump;

static int hpwdt_nmi_sourcing;





static void __iomem *pci_mem_addr;		/* the PCI-memory address */

static void __iomem *pci_mem_addr;		/* the PCI-memory address */

static unsigned long __iomem *hpwdt_timer_reg;

static unsigned long __iomem *hpwdt_timer_reg;
@@ -468,6 +470,7 @@ static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason, 
	if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)

	if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)

		return NOTIFY_OK;

		return NOTIFY_OK;





	if (hpwdt_nmi_sourcing) {

		spin_lock_irqsave(&rom_lock, rom_pl);

		spin_lock_irqsave(&rom_lock, rom_pl);

		if (!die_nmi_called)

		if (!die_nmi_called)

			asminline_call(&cmn_regs, cru_rom_addr);

			asminline_call(&cmn_regs, cru_rom_addr);
@@ -482,7 +485,7 @@ static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason, 
			panic("An NMI occurred, please see the Integrated "

			panic("An NMI occurred, please see the Integrated "

				"Management Log for details.\n");

				"Management Log for details.\n");

		}

		}



	}

	return NOTIFY_OK;

	return NOTIFY_OK;

}

}
@@ -627,11 +630,37 @@ static struct notifier_block die_notifier = { 
 *	Init & Exit

 *	Init & Exit

 */

 */





#ifdef ARCH_HAS_NMI_WATCHDOG

static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)

{

	/*

	 * If nmi_watchdog is turned off then we can turn on

	 * our nmi sourcing capability.

	 */

	if (!nmi_watchdog_active())

		hpwdt_nmi_sourcing = 1;

	else

		dev_warn(&dev->dev, "NMI sourcing is disabled. To enable this "

			"functionality you must reboot with nmi_watchdog=0.\n");

}

#else

static void __devinit hpwdt_check_nmi_sourcing(struct pci_dev *dev)

{

	dev_warn(&dev->dev, "NMI sourcing is disabled. "

		"Your kernel does not support a NMI Watchdog.\n");

}

#endif



static int __devinit hpwdt_init_one(struct pci_dev *dev,

static int __devinit hpwdt_init_one(struct pci_dev *dev,

					const struct pci_device_id *ent)

					const struct pci_device_id *ent)

{

{

	int retval;

	int retval;





	/*

	 * Check if we can do NMI sourcing or not

	 */

	hpwdt_check_nmi_sourcing(dev);



	/*

	/*

	 * First let's find out if we are on an iLO2 server. We will

	 * First let's find out if we are on an iLO2 server. We will

	 * not run on a legacy ASM box.

	 * not run on a legacy ASM box.