1 files changed, 17 insertions, 2 deletions

diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
index 28f047c61baa..ad0d2960b664 100644
--- a/drivers/irqchip/irq-gic-v2m.c
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -49,6 +49,9 @@
 /* APM X-Gene with GICv2m MSI_IIDR register value */
 #define XGENE_GICV2M_MSI_IIDR		0x06000170
 
+/* Broadcom NS2 GICv2m MSI_IIDR register value */
+#define BCM_NS2_GICV2M_MSI_IIDR		0x0000013f
+
 /* List of flags for specific v2m implementation */
 #define GICV2M_NEEDS_SPI_OFFSET		0x00000001
 
@@ -62,6 +65,7 @@ struct v2m_data {
 	void __iomem *base;	/* GICv2m virt address */
 	u32 spi_start;		/* The SPI number that MSIs start */
 	u32 nr_spis;		/* The number of SPIs for MSIs */
+	u32 spi_offset;		/* offset to be subtracted from SPI number */
 	unsigned long *bm;	/* MSI vector bitmap */
 	u32 flags;		/* v2m flags for specific implementation */
 };
@@ -102,7 +106,7 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 	msg->data = data->hwirq;
 
 	if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET)
-		msg->data -= v2m->spi_start;
+		msg->data -= v2m->spi_offset;
 }
 
 static struct irq_chip gicv2m_irq_chip = {
@@ -340,9 +344,20 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
 	 * different from the standard GICv2m implementation where
 	 * the MSI data is the absolute value within the range from
 	 * spi_start to (spi_start + num_spis).
+	 *
+	 * Broadom NS2 GICv2m implementation has an erratum where the MSI data
+	 * is 'spi_number - 32'
 	 */
-	if (readl_relaxed(v2m->base + V2M_MSI_IIDR) == XGENE_GICV2M_MSI_IIDR)
+	switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
+	case XGENE_GICV2M_MSI_IIDR:
+		v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
+		v2m->spi_offset = v2m->spi_start;
+		break;
+	case BCM_NS2_GICV2M_MSI_IIDR:
 		v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
+		v2m->spi_offset = 32;
+		break;
+	}
 
 	v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
 			  GFP_KERNEL);