From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi.kleen@intel.com>,
Ashok Raj <ashok.raj@intel.com>, Borislav Petkov <bp@suse.de>,
Tony Luck <tony.luck@intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
x86@kernel.org, sparclinux@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
Jacob Pan <jacob.jun.pan@intel.com>,
Clemens Ladisch <clemens@ladisch.de>,
Arnd Bergmann <arnd@arndb.de>,
Philippe Ombredanne <pombredanne@nexb.com>,
Kate Stewart <kstewart@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
iommu@lists.linux-foundation.org
Subject: [RFC PATCH 09/23] x86/hpet: Reserve timer for the HPET hardlockup detector
Date: Tue, 12 Jun 2018 17:57:29 -0700 [thread overview]
Message-ID: <1528851463-21140-10-git-send-email-ricardo.neri-calderon@linux.intel.com> (raw)
In-Reply-To: <1528851463-21140-1-git-send-email-ricardo.neri-calderon@linux.intel.com>
HPET timer 2 will be used to drive the HPET-based hardlockup detector.
Reserve such timer to ensure it cannot be used by user space programs or
clock events.
When looking for MSI-capable timers for clock events, skip timer 2 if
the HPET hardlockup detector is selected.
Also, do not assign an IO APIC pin to timer 2 of the HPET. A subsequent
changeset will handle the interrupt setup of the timer used for the
hardlockup detector.
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: x86@kernel.org
Cc: iommu@lists.linux-foundation.org
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
---
arch/x86/include/asm/hpet.h | 3 +++
arch/x86/kernel/hpet.c | 19 ++++++++++++++++---
2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/hpet.h b/arch/x86/include/asm/hpet.h
index 9e0afde..3266796 100644
--- a/arch/x86/include/asm/hpet.h
+++ b/arch/x86/include/asm/hpet.h
@@ -61,6 +61,9 @@
*/
#define HPET_MIN_PERIOD 100000UL
+/* Timer used for the hardlockup detector */
+#define HPET_WD_TIMER_NR 2
+
/* hpet memory map physical address */
extern unsigned long hpet_address;
extern unsigned long force_hpet_address;
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 3fa1d3f..b03faee 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -185,7 +185,8 @@ do { \
/*
* When the hpet driver (/dev/hpet) is enabled, we need to reserve
- * timer 0 and timer 1 in case of RTC emulation.
+ * timer 0 and timer 1 in case of RTC emulation. Timer 2 is reserved in case
+ * the HPET-based hardlockup detector is used.
*/
#ifdef CONFIG_HPET
@@ -195,7 +196,7 @@ static void hpet_reserve_platform_timers(unsigned int id)
{
struct hpet __iomem *hpet = hpet_virt_address;
struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
- unsigned int nrtimers, i;
+ unsigned int nrtimers, i, start_timer;
struct hpet_data hd;
nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
@@ -210,6 +211,13 @@ static void hpet_reserve_platform_timers(unsigned int id)
hpet_reserve_timer(&hd, 1);
#endif
+ if (IS_ENABLED(CONFIG_HARDLOCKUP_DETECTOR_HPET)) {
+ hpet_reserve_timer(&hd, HPET_WD_TIMER_NR);
+ start_timer = HPET_WD_TIMER_NR + 1;
+ } else {
+ start_timer = HPET_WD_TIMER_NR;
+ }
+
/*
* NOTE that hd_irq[] reflects IOAPIC input pins (LEGACY_8254
* is wrong for i8259!) not the output IRQ. Many BIOS writers
@@ -218,7 +226,7 @@ static void hpet_reserve_platform_timers(unsigned int id)
hd.hd_irq[0] = HPET_LEGACY_8254;
hd.hd_irq[1] = HPET_LEGACY_RTC;
- for (i = 2; i < nrtimers; timer++, i++) {
+ for (i = start_timer; i < nrtimers; timer++, i++) {
hd.hd_irq[i] = (readl(&timer->hpet_config) &
Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
}
@@ -630,6 +638,11 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
struct hpet_dev *hdev = &hpet_devs[num_timers_used];
unsigned int cfg = hpet_readl(HPET_Tn_CFG(i));
+ /* Do not use timer reserved for the HPET watchdog. */
+ if (IS_ENABLED(CONFIG_HARDLOCKUP_DETECTOR_HPET) &&
+ i == HPET_WD_TIMER_NR)
+ continue;
+
/* Only consider HPET timer with MSI support */
if (!(cfg & HPET_TN_FSB_CAP))
continue;
--
2.7.4
next prev parent reply other threads:[~2018-06-13 1:05 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-13 0:57 [RFC PATCH 00/23] Implement an HPET-based hardlockup detector Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 01/23] x86/apic: Add a parameter for the APIC delivery mode Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 02/23] genirq: Introduce IRQD_DELIVER_AS_NMI Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 03/23] genirq: Introduce IRQF_DELIVER_AS_NMI Ricardo Neri
2018-06-13 8:34 ` Peter Zijlstra
2018-06-13 8:59 ` Julien Thierry
2018-06-13 9:20 ` Thomas Gleixner
2018-06-13 9:36 ` Julien Thierry
2018-06-13 9:49 ` Julien Thierry
2018-06-13 9:57 ` Thomas Gleixner
2018-06-13 10:25 ` Julien Thierry
2018-06-13 10:06 ` Marc Zyngier
2018-06-15 2:12 ` Ricardo Neri
2018-06-15 8:01 ` Julien Thierry
2018-06-16 0:39 ` Ricardo Neri
2018-06-16 13:36 ` Thomas Gleixner
2018-06-13 0:57 ` [RFC PATCH 04/23] iommu/vt-d/irq_remapping: Add support for IRQCHIP_CAN_DELIVER_AS_NMI Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 05/23] x86/msi: " Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 06/23] x86/ioapic: Add support for IRQCHIP_CAN_DELIVER_AS_NMI with interrupt remapping Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 07/23] x86/hpet: Expose more functions to read and write registers Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 08/23] x86/hpet: Calculate ticks-per-second in a separate function Ricardo Neri
2018-06-13 0:57 ` Ricardo Neri [this message]
2018-06-13 0:57 ` [RFC PATCH 10/23] x86/hpet: Relocate flag definitions to a header file Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 11/23] x86/hpet: Configure the timer used by the hardlockup detector Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 12/23] kernel/watchdog: Introduce a struct for NMI watchdog operations Ricardo Neri
2018-06-13 7:41 ` Nicholas Piggin
2018-06-13 8:42 ` Peter Zijlstra
2018-06-13 9:26 ` Thomas Gleixner
2018-06-13 11:52 ` Nicholas Piggin
2018-06-14 1:31 ` Ricardo Neri
2018-06-14 2:32 ` Nicholas Piggin
2018-06-14 8:32 ` Thomas Gleixner
2018-06-15 2:21 ` Ricardo Neri
2018-06-14 1:26 ` Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 13/23] watchdog/hardlockup: Define a generic function to detect hardlockups Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 14/23] watchdog/hardlockup: Decouple the hardlockup detector from perf Ricardo Neri
2018-06-13 8:43 ` Peter Zijlstra
2018-06-14 1:19 ` Ricardo Neri
2018-06-14 1:41 ` Nicholas Piggin
2018-06-15 2:23 ` Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 15/23] kernel/watchdog: Add a function to obtain the watchdog_allowed_mask Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 16/23] watchdog/hardlockup: Add an HPET-based hardlockup detector Ricardo Neri
2018-06-13 5:23 ` Randy Dunlap
2018-06-14 1:00 ` Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 17/23] watchdog/hardlockup/hpet: Convert the timer's interrupt to NMI Ricardo Neri
2018-06-13 9:07 ` Peter Zijlstra
2018-06-15 2:07 ` Ricardo Neri
2018-06-13 9:40 ` Thomas Gleixner
2018-06-15 2:03 ` Ricardo Neri
2018-06-15 9:19 ` Thomas Gleixner
2018-06-16 0:51 ` Ricardo Neri
2018-06-16 13:24 ` Thomas Gleixner
2018-06-20 0:15 ` Ricardo Neri
2018-06-20 0:25 ` Randy Dunlap
2018-06-21 0:25 ` Ricardo Neri
2018-06-20 7:47 ` Thomas Gleixner
2018-06-13 0:57 ` [RFC PATCH 18/23] watchdog/hardlockup/hpet: Add the NMI watchdog operations Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 19/23] watchdog/hardlockup: Make arch_touch_nmi_watchdog() to hpet-based implementation Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 20/23] watchdog/hardlockup/hpet: Rotate interrupt among all monitored CPUs Ricardo Neri
2018-06-13 9:48 ` Thomas Gleixner
2018-06-15 2:16 ` Ricardo Neri
2018-06-15 10:29 ` Thomas Gleixner
2018-06-16 0:46 ` Ricardo Neri
2018-06-16 13:27 ` Thomas Gleixner
2018-06-13 0:57 ` [RFC PATCH 21/23] watchdog/hardlockup/hpet: Adjust timer expiration on the number of " Ricardo Neri
2018-06-13 0:57 ` [RFC PATCH 22/23] watchdog/hardlockup/hpet: Only enable the HPET watchdog via a boot parameter Ricardo Neri
2018-06-13 5:26 ` Randy Dunlap
2018-06-14 0:58 ` Ricardo Neri
2018-06-14 3:30 ` Randy Dunlap
2018-06-13 0:57 ` [RFC PATCH 23/23] watchdog/hardlockup: Activate the HPET-based lockup detector Ricardo Neri
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