[PATCH v2 1/2] acpi/x86: Fix improper handling of SCI INT for platforms supporting only IOAPIC mode

[Vikas C Sajjan <vikas.cha.sajjan@hpe.com>]

The platforms which support only IOAPIC mode and whose SCI INT is
greater than 16, passes SCI INT via FADT and not via MADT int src override
structure. In such cases current logic fails to handle it and throws error
"Invalid bus_irq %u for legacy override". This patch fixes it.

Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan@hpe.com>
Signed-off-by: Sunil V L <sunil.vl@hpe.com>
Signed-off-by: Abdul Lateef Attar <abdul-lateef.attar@hpe.com>
---
 arch/x86/kernel/acpi/boot.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index ef9e02e..40c24d1b 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -429,6 +429,37 @@ static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
 	return 0;
 }
 
+static int __init mp_register_ioapic_irq(u8 bus_irq, u8 polarity,
+						u8 trigger, u32 gsi)
+{
+	int ioapic;
+	int pin;
+	struct mpc_intsrc mp_irq;
+
+	/*
+	 * Convert 'gsi' to 'ioapic.pin'.
+	 */
+	ioapic = mp_find_ioapic(gsi);
+	if (ioapic < 0) {
+		pr_warn("Failed to find ioapic for gsi : %u\n", gsi);
+		return ioapic;
+	}
+
+	pin = mp_find_ioapic_pin(ioapic, gsi);
+
+	mp_irq.type = MP_INTSRC;
+	mp_irq.irqtype = mp_INT;
+	mp_irq.irqflag = (trigger << 2) | polarity;
+	mp_irq.srcbus = MP_ISA_BUS;
+	mp_irq.srcbusirq = bus_irq;	/* IRQ */
+	mp_irq.dstapic = mpc_ioapic_id(ioapic); /* APIC ID */
+	mp_irq.dstirq = pin;	/* INTIN# */
+
+	mp_save_irq(&mp_irq);
+
+	return 0;
+}
+
 static int __init
 acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
 {
@@ -473,7 +504,11 @@ static void __init acpi_sci_ioapic_setup(u8 bus_irq, u16 polarity, u16 trigger,
 	if (acpi_sci_flags & ACPI_MADT_POLARITY_MASK)
 		polarity = acpi_sci_flags & ACPI_MADT_POLARITY_MASK;
 
-	mp_override_legacy_irq(bus_irq, polarity, trigger, gsi);
+	if (bus_irq < NR_IRQS_LEGACY)
+		mp_override_legacy_irq(bus_irq, polarity, trigger, gsi);
+	else
+		mp_register_ioapic_irq(bus_irq, polarity, trigger, gsi);
+
 	acpi_penalize_sci_irq(bus_irq, trigger, polarity);
 
 	/*
-- 
1.9.1