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authorIngo Molnar <mingo@kernel.org>2021-03-21 22:16:08 +0100
committerIngo Molnar <mingo@kernel.org>2021-03-21 22:16:08 +0100
commitca8778c45e401067cefe2abbfb8b547c30d45908 (patch)
treec10beaf40adb2bbc6a8933f87ff9da7a5366bf42 /arch/x86/kernel/apic/io_apic.c
parent21d6a7dcbfba5e7b31f4e9d555a9be362578bfc3 (diff)
parent2c41fab1c60b02626c8153a1806a7a1e5d62aaf1 (diff)
Merge branch 'linus' into x86/cleanups, to resolve conflict
Conflicts: arch/x86/kernel/kprobes/ftrace.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/apic/io_apic.c')
-rw-r--r--arch/x86/kernel/apic/io_apic.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e90cbd6bdb66..d5c691a3208b 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1032,6 +1032,16 @@ static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
if (idx >= 0 && test_bit(mp_irqs[idx].srcbus, mp_bus_not_pci)) {
irq = mp_irqs[idx].srcbusirq;
legacy = mp_is_legacy_irq(irq);
+ /*
+ * IRQ2 is unusable for historical reasons on systems which
+ * have a legacy PIC. See the comment vs. IRQ2 further down.
+ *
+ * If this gets removed at some point then the related code
+ * in lapic_assign_system_vectors() needs to be adjusted as
+ * well.
+ */
+ if (legacy && irq == PIC_CASCADE_IR)
+ return -EINVAL;
}
mutex_lock(&ioapic_mutex);