[PATCH 4.9 48/86] watchdog: hpwdt: Check source of NMI

Greg Kroah-Hartman
2018-03-16T15:23:11Z

From: Jerry Hoemann <jerry.hoemann@hpe.com>

commit 838534e50e2e5c1e644e30ab6cb28da88eb31368 upstream.

Do not claim the NMI (i.e. return NMI_DONE) if the source of
the NMI isn't the iLO watchdog or debug.

Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/watchdog/hpwdt.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -52,6 +52,7 @@ static char expect_release;
static unsigned long hpwdt_is_open;

static void __iomem *pci_mem_addr; /* the PCI-memory address */
+static unsigned long __iomem *hpwdt_nmistat;
static unsigned long __iomem *hpwdt_timer_reg;
static unsigned long __iomem *hpwdt_timer_con;

@@ -474,6 +475,11 @@ static int hpwdt_time_left(void)
return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
}

+static int hpwdt_my_nmi(void)
+{
+ return ioread8(hpwdt_nmistat) & 0x6;
+}
+
#ifdef CONFIG_HPWDT_NMI_DECODING
/*
* NMI Handler
@@ -486,6 +492,9 @@ static int hpwdt_pretimeout(unsigned int
if (!hpwdt_nmi_decoding)
return NMI_DONE;

+ if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi())
+ return NMI_DONE;
+
spin_lock_irqsave(&rom_lock, rom_pl);
if (!die_nmi_called && !is_icru && !is_uefi)
asminline_call(&cmn_regs, cru_rom_addr);
@@ -842,6 +851,7 @@ static int hpwdt_init_one(struct pci_dev
retval = -ENOMEM;
goto error_pci_iomap;
}
+ hpwdt_nmistat = pci_mem_addr + 0x6e;
hpwdt_timer_reg = pci_mem_addr + 0x70;
hpwdt_timer_con = pci_mem_addr + 0x72;