irqchip/gic-v3: Describe the SGI range

As we are about to start making use of SGIs in a more conventional
way, let's describe it is the GICv3 list of interrupt types.
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

drivers/irqchip/irq-gic-v3.c

@@ -112,6 +112,7 @@ static DEFINE_PER_CPU(bool, has_rss);
 #define DEFAULT_PMR_VALUE	0xf0
 
 enum gic_intid_range {
+	SGI_RANGE,
 	PPI_RANGE,
 	SPI_RANGE,
 	EPPI_RANGE,
@@ -123,6 +124,8 @@ enum gic_intid_range {
 static enum gic_intid_range __get_intid_range(irq_hw_number_t hwirq)
 {
 	switch (hwirq) {
+	case 0 ... 15:
+		return SGI_RANGE;
 	case 16 ... 31:
 		return PPI_RANGE;
 	case 32 ... 1019:
@@ -148,15 +151,22 @@ static inline unsigned int gic_irq(struct irq_data *d)
 	return d->hwirq;
 }
 
-static inline int gic_irq_in_rdist(struct irq_data *d)
+static inline bool gic_irq_in_rdist(struct irq_data *d)
 {
-	enum gic_intid_range range = get_intid_range(d);
-	return range == PPI_RANGE || range == EPPI_RANGE;
+	switch (get_intid_range(d)) {
+	case SGI_RANGE:
+	case PPI_RANGE:
+	case EPPI_RANGE:
+		return true;
+	default:
+		return false;
+	}
 }
 
 static inline void __iomem *gic_dist_base(struct irq_data *d)
 {
 	switch (get_intid_range(d)) {
+	case SGI_RANGE:
 	case PPI_RANGE:
 	case EPPI_RANGE:
 		/* SGI+PPI -> SGI_base for this CPU */
@@ -253,6 +263,7 @@ static void gic_enable_redist(bool enable)
 static u32 convert_offset_index(struct irq_data *d, u32 offset, u32 *index)
 {
 	switch (get_intid_range(d)) {
+	case SGI_RANGE:
 	case PPI_RANGE:
 	case SPI_RANGE:
 		*index = d->hwirq;
@@ -1277,6 +1288,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
 		chip = &gic_eoimode1_chip;
 
 	switch (__get_intid_range(hw)) {
+	case SGI_RANGE:
 	case PPI_RANGE:
 	case EPPI_RANGE:
 		irq_set_percpu_devid(irq);