x86/jailhouse: Enable PMTIMER

Jailhouse exposes the PMTIMER as only reference clock to all cells. Pick
up its address from the setup data. Allow to enable the Linux support of
it by relaxing its strict dependency on ACPI.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/6d5c3fadd801eb3fba9510e2d3db14a9c404a1a0.1511770314.git.jan.kiszka@siemens.com

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fbea8d1..a936e29 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -799,6 +799,7 @@ config PARAVIRT_CLOCK
 config JAILHOUSE_GUEST
        bool "Jailhouse non-root cell support"
        depends on X86_64
+       select X86_PM_TIMER
        ---help---
          This option allows to run Linux as guest in a Jailhouse non-root
          cell. You can leave this option disabled if you only want to start

diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index 57f4996..21c1077 100644 (file)
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -8,6 +8,7 @@
  *  Jan Kiszka <jan.kiszka@siemens.com>
  */
 
+#include <linux/acpi_pmtmr.h>
 #include <linux/kernel.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
@@ -91,6 +92,9 @@ static void __init jailhouse_init_platform(void)
 
        if (setup_data.compatible_version > JAILHOUSE_SETUP_REQUIRED_VERSION)
                panic("Jailhouse: Unsupported setup data structure");
+
+       pmtmr_ioport = setup_data.pm_timer_address;
+       pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);
 }
 
 bool jailhouse_paravirt(void)

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 4650539..d650c5b 100644 (file)
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -361,22 +361,6 @@ config ACPI_PCI_SLOT
          i.e., segment/bus/device/function tuples, with physical slots in
          the system.  If you are unsure, say N.
 
-config X86_PM_TIMER
-       bool "Power Management Timer Support" if EXPERT
-       depends on X86
-       default y
-       help
-         The Power Management Timer is available on all ACPI-capable,
-         in most cases even if ACPI is unusable or blacklisted.
-
-         This timing source is not affected by power management features
-         like aggressive processor idling, throttling, frequency and/or
-         voltage scaling, unlike the commonly used Time Stamp Counter
-         (TSC) timing source.
-
-         You should nearly always say Y here because many modern
-         systems require this timer. 
-
 config ACPI_CONTAINER
        bool "Container and Module Devices"
        default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU)
@@ -564,3 +548,19 @@ config TPS68470_PMIC_OPREGION
          using this, are probed.
 
 endif  # ACPI
+
+config X86_PM_TIMER
+       bool "Power Management Timer Support" if EXPERT
+       depends on X86 && (ACPI || JAILHOUSE_GUEST)
+       default y
+       help
+         The Power Management Timer is available on all ACPI-capable,
+         in most cases even if ACPI is unusable or blacklisted.
+
+         This timing source is not affected by power management features
+         like aggressive processor idling, throttling, frequency and/or
+         voltage scaling, unlike the commonly used Time Stamp Counter
+         (TSC) timing source.
+
+         You should nearly always say Y here because many modern
+         systems require this timer.