[RFC PATCH 24/32] arm64, irqchip/gic-v3, ACPI: Move MADT GICC enabled check into a helper

[James Morse <james.morse@arm.com>]

ACPI, irqchip and the architecture code all inspect the MADT
enabled bit for a GICC entry in the MADT.

The addition of an 'online capable' bit means all these sites need updating.

Move the current checks behind a helper to make future updates easier.

Signed-off-by: James Morse <james.morse@arm.com>
---
 arch/arm64/kernel/smp.c       |  2 +-
 drivers/acpi/processor_core.c |  2 +-
 drivers/irqchip/irq-gic-v3.c  | 10 ++++------
 include/linux/acpi.h          |  5 +++++
 4 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index ffc5d76cf695..5669b013c2b7 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -525,7 +525,7 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
 {
 	u64 hwid = processor->arm_mpidr;
 
-	if (!(processor->flags & ACPI_MADT_ENABLED)) {
+	if (!acpi_gicc_is_usable(processor)) {
 		pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid);
 		return;
 	}
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 2ac48cda5b20..1ba273622faa 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -90,7 +90,7 @@ static int map_gicc_mpidr(struct acpi_subtable_header *entry,
 	struct acpi_madt_generic_interrupt *gicc =
 	    container_of(entry, struct acpi_madt_generic_interrupt, header);
 
-	if (!(gicc->flags & ACPI_MADT_ENABLED))
+	if (!acpi_gicc_is_usable(gicc))
 		return -ENODEV;
 
 	/* device_declaration means Device object in DSDT, in the
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 997104d4338e..d484cccfd612 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -2189,8 +2189,7 @@ gic_acpi_parse_madt_gicc(union acpi_subtable_headers *header,
 	u32 size = reg == GIC_PIDR2_ARCH_GICv4 ? SZ_64K * 4 : SZ_64K * 2;
 	void __iomem *redist_base;
 
-	/* GICC entry which has !ACPI_MADT_ENABLED is not unusable so skip */
-	if (!(gicc->flags & ACPI_MADT_ENABLED))
+	if (!acpi_gicc_is_usable(gicc))
 		return 0;
 
 	redist_base = ioremap(gicc->gicr_base_address, size);
@@ -2240,7 +2239,7 @@ static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header,
 	 * If GICC is enabled and has valid gicr base address, then it means
 	 * GICR base is presented via GICC
 	 */
-	if ((gicc->flags & ACPI_MADT_ENABLED) && gicc->gicr_base_address) {
+	if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) {
 		acpi_data.enabled_rdists++;
 		return 0;
 	}
@@ -2249,7 +2248,7 @@ static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header,
 	 * It's perfectly valid firmware can pass disabled GICC entry, driver
 	 * should not treat as errors, skip the entry instead of probe fail.
 	 */
-	if (!(gicc->flags & ACPI_MADT_ENABLED))
+	if (!acpi_gicc_is_usable(gicc))
 		return 0;
 
 	return -ENODEV;
@@ -2308,8 +2307,7 @@ static int __init gic_acpi_parse_virt_madt_gicc(union acpi_subtable_headers *hea
 	int maint_irq_mode;
 	static int first_madt = true;
 
-	/* Skip unusable CPUs */
-	if (!(gicc->flags & ACPI_MADT_ENABLED))
+	if (!acpi_gicc_is_usable(gicc))
 		return 0;
 
 	maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ?
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index a59bca4dbcd5..d8e59953a27f 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -267,6 +267,11 @@ acpi_table_parse_cedt(enum acpi_cedt_type id,
 int acpi_parse_mcfg (struct acpi_table_header *header);
 void acpi_table_print_madt_entry (struct acpi_subtable_header *madt);
 
+static inline bool acpi_gicc_is_usable(struct acpi_madt_generic_interrupt *gicc)
+{
+	return (gicc->flags & ACPI_MADT_ENABLED);
+}
+
 /* the following numa functions are architecture-dependent */
 void acpi_numa_slit_init (struct acpi_table_slit *slit);
 
-- 
2.30.2