x86/nmi: Add new NMI queues to deal with IO_CHK and SERR

In discussions with Thomas Mingarelli about hpwdt, he explained
to me some issues they were some when using their virtual NMI
button to test the hpwdt driver.

It turns out the virtual NMI button used on HP's machines do no
send unknown NMIs but instead send IO_CHK NMIs.  The way the
kernel code is written, the hpwdt driver can not register itself
against that type of NMI and therefore can not successfully
capture system information before panic'ing.

To solve this I created two new NMI queues to allow driver to
register against the IO_CHK and SERR NMIs.  Or in the hpwdt all
three (if you include unknown NMIs too).

The change is straightforward and just mimics what the unknown
NMI does.

Reported-and-tested-by: Thomas Mingarelli <thomas.mingarelli@hp.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1333051877-15755-3-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 20 insertions, 7 deletions

diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index 4000b8038cac..6e414b501d58 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -725,19 +725,32 @@ static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
          * Only one function can register for NMI_UNKNOWN
          */
         retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
-        if (retval != 0) {
-                dev_warn(&dev->dev,
-                        "Unable to register a die notifier (err=%d).\n",
-                        retval);
-                if (cru_rom_addr)
-                        iounmap(cru_rom_addr);
-        }
+        if (retval)
+                goto error;
+        retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
+        if (retval)
+                goto error1;
+        retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
+        if (retval)
+                goto error2;
 
         dev_info(&dev->dev,
                         "HP Watchdog Timer Driver: NMI decoding initialized"
                         ", allow kernel dump: %s (default = 0/OFF)\n",
                         (allow_kdump == 0) ? "OFF" : "ON");
         return 0;
+
+error2:
+        unregister_nmi_handler(NMI_SERR, "hpwdt");
+error1:
+        unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
+error:
+        dev_warn(&dev->dev,
+                "Unable to register a die notifier (err=%d).\n",
+                retval);
+        if (cru_rom_addr)
+                iounmap(cru_rom_addr);
+        return retval;
 }
 
 static void hpwdt_exit_nmi_decoding(void)