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authorDuc Dang <dhdang@apm.com>2015-10-07 00:32:38 +0200
committerMarc Zyngier <marc.zyngier@arm.com>2015-10-09 23:16:58 +0200
commitee5f7d6462c56ba083d5d80aa0d69914068a59ae (patch)
treed9c03c9b09537ee96b35e43bcf51e53e33d157e2 /drivers/irqchip/irq-gic-v2m.c
parentarm64: Update booting requirements for GICv3 in GICv2 mode (diff)
downloadlinux-ee5f7d6462c56ba083d5d80aa0d69914068a59ae.tar.xz
linux-ee5f7d6462c56ba083d5d80aa0d69914068a59ae.zip
irqchip/gic-v2m: Add workaround for APM X-Gene GICv2m erratum
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. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'drivers/irqchip/irq-gic-v2m.c')
-rw-r--r--drivers/irqchip/irq-gic-v2m.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
index 12985daa66ab..9a36ab0b544c 100644
--- a/drivers/irqchip/irq-gic-v2m.c
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -37,12 +37,19 @@
#define V2M_MSI_SETSPI_NS 0x040
#define V2M_MIN_SPI 32
#define V2M_MAX_SPI 1019
+#define V2M_MSI_IIDR 0xFCC
#define V2M_MSI_TYPER_BASE_SPI(x) \
(((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
#define V2M_MSI_TYPER_NUM_SPI(x) ((x) & V2M_MSI_TYPER_NUM_MASK)
+/* APM X-Gene with GICv2m MSI_IIDR register value */
+#define XGENE_GICV2M_MSI_IIDR 0x06000170
+
+/* List of flags for specific v2m implementation */
+#define GICV2M_NEEDS_SPI_OFFSET 0x00000001
+
struct v2m_data {
spinlock_t msi_cnt_lock;
struct resource res; /* GICv2m resource */
@@ -50,6 +57,7 @@ struct v2m_data {
u32 spi_start; /* The SPI number that MSIs start */
u32 nr_spis; /* The number of SPIs for MSIs */
unsigned long *bm; /* MSI vector bitmap */
+ u32 flags; /* v2m flags for specific implementation */
};
static void gicv2m_mask_msi_irq(struct irq_data *d)
@@ -98,6 +106,9 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
msg->address_hi = upper_32_bits(addr);
msg->address_lo = lower_32_bits(addr);
msg->data = data->hwirq;
+
+ if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET)
+ msg->data -= v2m->spi_start;
}
static struct irq_chip gicv2m_irq_chip = {
@@ -266,6 +277,17 @@ static int __init gicv2m_init_one(struct device_node *node,
goto err_iounmap;
}
+ /*
+ * 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)
+ v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
+
v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
GFP_KERNEL);
if (!v2m->bm) {