x86: fix mpparse/acpi interaction

Sitsofe Wheeler reported boot problems on linux-next.

It looks like the same issue as found by Soeren Sandman in 7575217f656a93,
"x86: initialize all fields of mp_irqs[mp_irq_entries]".

But his fix is also not complete, as dstapic is used before it assigned.

Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Bisected-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 4 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6170c6aeaf79..2ddfabae382b 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1019,6 +1019,11 @@ void __init mp_config_acpi_legacy_irqs(void)
         for (i = 0; i < 16; i++) {
                 int idx;
 
+                mp_irqs[mp_irq_entries].mp_type = MP_INTSRC;
+                mp_irqs[mp_irq_entries].mp_irqflag = 0; /* Conforming */
+                mp_irqs[mp_irq_entries].mp_srcbus = MP_ISA_BUS;
+                mp_irqs[mp_irq_entries].mp_dstapic = mp_ioapics[ioapic].mp_apicid;
+
                 for (idx = 0; idx < mp_irq_entries; idx++) {
                         struct mp_config_intsrc *irq = mp_irqs + idx;
 
@@ -1039,10 +1044,6 @@ void __init mp_config_acpi_legacy_irqs(void)
                         continue;       /* IRQ already used */
                 }
 
-                mp_irqs[mp_irq_entries].mp_type = MP_INTSRC;
-                mp_irqs[mp_irq_entries].mp_irqflag = 0; /* Conforming */
-                mp_irqs[mp_irq_entries].mp_srcbus = MP_ISA_BUS;
-                mp_irqs[mp_irq_entries].mp_dstapic = mp_ioapics[ioapic].mp_apicid;
                 mp_irqs[mp_irq_entries].mp_irqtype = mp_INT;
                 mp_irqs[mp_irq_entries].mp_srcbusirq = i;       /* Identity mapped */
                 mp_irqs[mp_irq_entries].mp_dstirq = i;