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watchdog, hpwdt: Remove priority option for NMI callback

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The NMI_UNKNOWN bucket only allows for one function to register
to it. The reason for that is because only functions which can
not determine if the NMI belongs to them or not should register
and would like to assume/swallow any NMI they see.

As a result it doesn't make sense to let more than one function
like this register.  In fact, letting a second function fail
allows us to know that more than one function is going to
swallow NMIs on the current system. This is better than silently
being ignored.

Therefore hpwdt's priority mechanism doesn't make sense any
more.  They will be always first on the NMI_UNKNOWN queue, if
they register.

Removing this parameter cleans up the code and simplifies things
for the next patch which changes how nmis are registered.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Thomas Mingarelli <thomas.mingarelli@hp.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
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/1333051877-15755-2-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Don Zickus 2012-03-29 16:11:15 -04:00 committed by Ingo Molnar
parent 625056b65e
commit 09ee101436
1 changed files with 4 additions and 15 deletions
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19
drivers/watchdog/hpwdt.c
View file

@ -147,7 +147,6 @@ struct cmn_registers {
static unsigned int hpwdt_nmi_decoding; static unsigned int hpwdt_nmi_decoding;
static unsigned int allow_kdump; static unsigned int allow_kdump;
static unsigned int priority; /* hpwdt at end of die_notify list */
static unsigned int is_icru; static unsigned int is_icru;
static DEFINE_SPINLOCK(rom_lock); static DEFINE_SPINLOCK(rom_lock);
static void *cru_rom_addr; static void *cru_rom_addr;
@ -723,13 +722,9 @@ static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
} }
/* /*
* If the priority is set to 1, then we will be put first on the * Only one function can register for NMI_UNKNOWN
* die notify list to handle a critical NMI. The default is to
* be last so other users of the NMI signal can function.
*/ */
retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
(priority) ? NMI_FLAG_FIRST : 0,
"hpwdt");
if (retval != 0) { if (retval != 0) {
dev_warn(&dev->dev, dev_warn(&dev->dev,
"Unable to register a die notifier (err=%d).\n", "Unable to register a die notifier (err=%d).\n",
@ -740,10 +735,8 @@ static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
dev_info(&dev->dev, dev_info(&dev->dev,
"HP Watchdog Timer Driver: NMI decoding initialized" "HP Watchdog Timer Driver: NMI decoding initialized"
", allow kernel dump: %s (default = 0/OFF)" ", allow kernel dump: %s (default = 0/OFF)\n",
", priority: %s (default = 0/LAST).\n", (allow_kdump == 0) ? "OFF" : "ON");
(allow_kdump == 0) ? "OFF" : "ON",
(priority == 0) ? "LAST" : "FIRST");
return 0; return 0;
} }
@ -881,10 +874,6 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
#ifdef CONFIG_HPWDT_NMI_DECODING #ifdef CONFIG_HPWDT_NMI_DECODING
module_param(allow_kdump, int, 0); module_param(allow_kdump, int, 0);
MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs"); MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
module_param(priority, int, 0);
MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
" (default = 0/Last)\n");
#endif /* !CONFIG_HPWDT_NMI_DECODING */ #endif /* !CONFIG_HPWDT_NMI_DECODING */
module_init(hpwdt_init); module_init(hpwdt_init);