APM X-Gene GICv2m implementation has an erratum where the
MSI data needs to be the offset from the spi_start in order to
trigger the correct MSI interrupt. This is 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)
of each v2m frame.
This patch reads MSI_IIDR register (present in all GICv2m
implementations) to identify X-Gene GICv2m implementation and
apply workaround to change the data portion of MSI vector.
Signed-off-by: Duc Dang <dhd...@apm.com>
---
drivers/irqchip/irq-gic-v2m.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
index db04fc1..470972c 100644
--- a/drivers/irqchip/irq-gic-v2m.c
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -43,6 +43,10 @@
#define V2M_MSI_TYPER_NUM_SPI(x) ((x) & V2M_MSI_TYPER_NUM_MASK)
+#define V2M_MSI_IIDR 0xFCC
+/* APM X-Gene with GICv2m MSI_IIDR register value */
+#define XGENE_GICV2M_MSI_IIDR 0x06000170
+
struct v2m_data {
spinlock_t msi_cnt_lock;
struct resource res; /* GICv2m resource */
@@ -98,6 +102,16 @@ static void gicv2m_compose_msi_msg(struct irq_data *data,
struct msi_msg *msg)
msg->address_hi = (u32) (addr >> 32);
msg->address_lo = (u32) (addr);
msg->data = data->hwirq;
+ /*
+ * APM X-Gene GICv2m implementation has an erratum where
+ * the MSI data needs to be the offset from the spi_start
+ * in order to trigger the correct MSI interrupt. This is
+ * 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).
+ */
+ if (readl_relaxed(v2m->base + V2M_MSI_IIDR) == XGENE_GICV2M_MSI_IIDR)
+ msg->data = data->hwirq - v2m->spi_start;
}
static struct irq_chip gicv2m_irq_chip = {
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
