summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/apic/apic.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2020-02-09 12:11:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-02-09 12:11:12 -0800
commit1a2a76c2685a29e46d7b37e752ccea7b15aa8e24 (patch)
tree0fa4d2796b0951e815468ac3c611068e5b87d984 /arch/x86/kernel/apic/apic.c
parentf41377609a722fec65f4b0df4e8dc5ea946fb866 (diff)
parent0f378d73d429d5f73fe2f00be4c9a15dbe9779ee (diff)
downloadlinux-1a2a76c2685a29e46d7b37e752ccea7b15aa8e24.tar.gz
linux-1a2a76c2685a29e46d7b37e752ccea7b15aa8e24.tar.bz2
linux-1a2a76c2685a29e46d7b37e752ccea7b15aa8e24.zip
Merge tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner: "A set of fixes for X86: - Ensure that the PIT is set up when the local APIC is disable or configured in legacy mode. This is caused by an ordering issue introduced in the recent changes which skip PIT initialization when the TSC and APIC frequencies are already known. - Handle malformed SRAT tables during early ACPI parsing which caused an infinite loop anda boot hang. - Fix a long standing race in the affinity setting code which affects PCI devices with non-maskable MSI interrupts. The problem is caused by the non-atomic writes of the MSI address (destination APIC id) and data (vector) fields which the device uses to construct the MSI message. The non-atomic writes are mandated by PCI. If both fields change and the device raises an interrupt after writing address and before writing data, then the MSI block constructs a inconsistent message which causes interrupts to be lost and subsequent malfunction of the device. The fix is to redirect the interrupt to the new vector on the current CPU first and then switch it over to the new target CPU. This allows to observe an eventually raised interrupt in the transitional stage (old CPU, new vector) to be observed in the APIC IRR and retriggered on the new target CPU and the new vector. The potential spurious interrupts caused by this are harmless and can in the worst case expose a buggy driver (all handlers have to be able to deal with spurious interrupts as they can and do happen for various reasons). - Add the missing suspend/resume mechanism for the HYPERV hypercall page which prevents resume hibernation on HYPERV guests. This change got lost before the merge window. - Mask the IOAPIC before disabling the local APIC to prevent potentially stale IOAPIC remote IRR bits which cause stale interrupt lines after resume" * tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Mask IOAPIC entries when disabling the local APIC x86/hyperv: Suspend/resume the hypercall page for hibernation x86/apic/msi: Plug non-maskable MSI affinity race x86/boot: Handle malformed SRAT tables during early ACPI parsing x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
-rw-r--r--arch/x86/kernel/apic/apic.c30
1 files changed, 25 insertions, 5 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 28446fa6bf18..5f973fed3c9f 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -830,8 +830,17 @@ bool __init apic_needs_pit(void)
if (!tsc_khz || !cpu_khz)
return true;
- /* Is there an APIC at all? */
- if (!boot_cpu_has(X86_FEATURE_APIC))
+ /* Is there an APIC at all or is it disabled? */
+ if (!boot_cpu_has(X86_FEATURE_APIC) || disable_apic)
+ return true;
+
+ /*
+ * If interrupt delivery mode is legacy PIC or virtual wire without
+ * configuration, the local APIC timer wont be set up. Make sure
+ * that the PIT is initialized.
+ */
+ if (apic_intr_mode == APIC_PIC ||
+ apic_intr_mode == APIC_VIRTUAL_WIRE_NO_CONFIG)
return true;
/* Virt guests may lack ARAT, but still have DEADLINE */
@@ -1322,7 +1331,7 @@ void __init sync_Arb_IDs(void)
enum apic_intr_mode_id apic_intr_mode __ro_after_init;
-static int __init apic_intr_mode_select(void)
+static int __init __apic_intr_mode_select(void)
{
/* Check kernel option */
if (disable_apic) {
@@ -1384,6 +1393,12 @@ static int __init apic_intr_mode_select(void)
return APIC_SYMMETRIC_IO;
}
+/* Select the interrupt delivery mode for the BSP */
+void __init apic_intr_mode_select(void)
+{
+ apic_intr_mode = __apic_intr_mode_select();
+}
+
/*
* An initial setup of the virtual wire mode.
*/
@@ -1440,8 +1455,6 @@ void __init apic_intr_mode_init(void)
{
bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
- apic_intr_mode = apic_intr_mode_select();
-
switch (apic_intr_mode) {
case APIC_PIC:
pr_info("APIC: Keep in PIC mode(8259)\n");
@@ -2626,6 +2639,13 @@ static int lapic_suspend(void)
#endif
local_irq_save(flags);
+
+ /*
+ * Mask IOAPIC before disabling the local APIC to prevent stale IRR
+ * entries on some implementations.
+ */
+ mask_ioapic_entries();
+
disable_local_APIC();
irq_remapping_disable();