From 74c967aaffeace8a85fc3d7be773fd165ebde3da Mon Sep 17 00:00:00 2001 From: Ray Jui Date: Thu, 5 May 2016 09:32:01 -0700 Subject: [PATCH] irqchip/gic-v2m: Add workaround for Broadcom NS2 GICv2m erratum Alex Barba discovered Broadcom NS2 GICv2m implementation has an erratum where the MSI data needs to be the SPI number subtracted by an offset of 32, for the correct MSI interrupt to be triggered. Here we are adding the workaround based on readings from the MSI_IIDR register, which contains a value unique to Broadcom NS2 GICv2m Reported-by: Alex Barba Acked-by: Marc Zyngier Signed-off-by: Ray Jui Signed-off-by: Marc Zyngier --- drivers/irqchip/irq-gic-v2m.c | 19 +++++++++++++++++-- 1 file 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);