[PATCH 4.14 022/118] x86/acpi: Handle SCI interrupts above legacy space gracefully

From: Greg Kroah-Hartman
Date: Mon Jan 15 2018 - 07:47:56 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vikas C Sajjan <vikas.cha.sajjan@xxxxxxx>

commit 252714155f04c5d16989cb3aadb85fd1b5772f99 upstream.

Platforms which support only IOAPIC mode, pass the SCI information above
the legacy space (0-15) via the FADT mechanism and not via MADT.

In such cases mp_override_legacy_irq() which is invoked from
acpi_sci_ioapic_setup() to register SCI interrupts fails for interrupts
greater equal 16, since it is meant to handle only the legacy space and
emits error "Invalid bus_irq %u for legacy override".

Add a new function to handle SCI interrupts >= 16 and invoke it
conditionally in acpi_sci_ioapic_setup().

The code duplication due to this new function will be cleaned up in a
separate patch.

Co-developed-by: Sunil V L <sunil.vl@xxxxxxx>
Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan@xxxxxxx>
Signed-off-by: Sunil V L <sunil.vl@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Abdul Lateef Attar <abdul-lateef.attar@xxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: kkamagui@xxxxxxxxx
Cc: linux-acpi@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/1510848825-21965-2-git-send-email-vikas.cha.sajjan@xxxxxxx
Cc: Jean Delvare <jdelvare@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kernel/acpi/boot.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)

--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -429,6 +429,34 @@ static int mp_config_acpi_gsi(struct dev
return 0;
}

+static int __init mp_register_ioapic_irq(u8 bus_irq, u8 polarity,
+ u8 trigger, u32 gsi)
+{
+ struct mpc_intsrc mp_irq;
+ int ioapic, pin;
+
+ /* Convert 'gsi' to 'ioapic.pin'(INTIN#) */
+ 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;
+ mp_irq.dstapic = mpc_ioapic_id(ioapic);
+ mp_irq.dstirq = pin;
+
+ mp_save_irq(&mp_irq);
+
+ return 0;
+}
+
static int __init
acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
{
@@ -473,7 +501,11 @@ static void __init acpi_sci_ioapic_setup
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);

/*