The FreeScale PowerQUICC-III-compatible (mpc85xx/mpc86xx) MPICs do not
correctly report the number of hardware interrupt sources, so software
needs to override the detected value with "256".
To avoid needing to write custom board-specific code to detect that
scenario, allow it to be easily overridden in the device-tree.
Signed-off-by: Kyle Moffett <Kyle.D.Moffett@xxxxxxxxxx>
---
.../devicetree/bindings/powerpc/fsl/mpic.txt | 7 +++
arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi | 1 +
arch/powerpc/sysdev/mpic.c | 46 +++++++++++---------
3 files changed, 34 insertions(+), 20 deletions(-)
diff --git a/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt b/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt
index b393ccf..dc57446 100644
--- a/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt
+++ b/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt
@@ -70,6 +70,13 @@ PROPERTIES
If present the MPIC will be assumed to only be able to route
non-IPI interrupts to a single CPU at a time (EG: Freescale MPIC).
+ - last-interrupt-source
+ Usage: optional
+ Value type: <u32>
+ Some MPICs do not correctly report the number of hardware sources
+ in the global feature registers. If specified, this field will
+ override the value read from MPIC_GREG_FEATURE_LAST_SRC.
+
INTERRUPT SPECIFIER DEFINITION
Interrupt specifiers consists of 4 cells encoded as
diff --git a/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi b/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi
index 658bd81..fdedf7b 100644
--- a/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi
+++ b/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi
@@ -41,6 +41,7 @@ mpic: pic@40000 {
device_type = "open-pic";
big-endian;
single-cpu-affinity;
+ last-interrupt-source = <255>;
};
timer@41100 {
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index cbffeb7..90171d4 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1149,6 +1149,7 @@ struct mpic * __init mpic_alloc(struct device_node *node,
u32 greg_feature;
const char *vers;
const u32 *psrc;
+ u32 last_irq;
/* Default MPIC search parameters */
static const struct of_device_id __initconst mpic_device_id[] = {
@@ -1220,7 +1221,6 @@ struct mpic * __init mpic_alloc(struct device_node *node,
mpic->hc_tm = mpic_tm_chip;
mpic->hc_tm.name = name;
- mpic->isu_size = isu_size;
mpic->num_sources = 0; /* so far */
if (mpic->flags & MPIC_LARGE_VECTORS)
@@ -1308,20 +1308,6 @@ struct mpic * __init mpic_alloc(struct device_node *node,
| MPIC_GREG_GCONF_MCK);
/*
- * Read feature register. For non-ISU MPICs, num sources as well. On
- * ISU MPICs, sources are counted as ISUs are added
- */
- greg_feature = mpic_read(mpic->gregs, MPIC_INFO(GREG_FEATURE_0));
- if (isu_size == 0) {
- if (irq_count)
- mpic->num_sources = irq_count;
- else
- mpic->num_sources =
- ((greg_feature & MPIC_GREG_FEATURE_LAST_SRC_MASK)
- >> MPIC_GREG_FEATURE_LAST_SRC_SHIFT) + 1;
- }
-
- /*
* The MPIC driver will crash if there are more cores than we
* can initialize, so we may as well catch that problem here.
*/
@@ -1336,18 +1322,38 @@ struct mpic * __init mpic_alloc(struct device_node *node,
0x1000);
}
+ /*
+ * Read feature register. For non-ISU MPICs, num sources as well. On
+ * ISU MPICs, sources are counted as ISUs are added
+ */
+ greg_feature = mpic_read(mpic->gregs, MPIC_INFO(GREG_FEATURE_0));
+
+ /*
+ * By default, the last source number comes from the MPIC, but the
+ * device-tree and board support code can override it on buggy hw.
+ */
+ last_irq = (greg_feature & MPIC_GREG_FEATURE_LAST_SRC_MASK)
+ >> MPIC_GREG_FEATURE_LAST_SRC_SHIFT;
+ of_property_read_u32(mpic->node, "last-interrupt-source", &last_irq);
+ if (irq_count)
+ last_irq = irq_count - 1;
+
/* Initialize main ISU if none provided */
- if (mpic->isu_size == 0) {
- mpic->isu_size = mpic->num_sources;
+ if (!isu_size) {
+ isu_size = last_irq + 1;
+ mpic->num_sources = isu_size;
mpic_map(mpic, mpic->paddr, &mpic->isus[0],
- MPIC_INFO(IRQ_BASE), MPIC_INFO(IRQ_STRIDE) * mpic->isu_size);
+ MPIC_INFO(IRQ_BASE),
+ MPIC_INFO(IRQ_STRIDE) * isu_size);
}
+
+ mpic->isu_size = isu_size;
mpic->isu_shift = 1 + __ilog2(mpic->isu_size - 1);
mpic->isu_mask = (1 << mpic->isu_shift) - 1;
mpic->irqhost = irq_alloc_host(mpic->node, IRQ_HOST_MAP_LINEAR,
- isu_size ? isu_size : mpic->num_sources,
- &mpic_host_ops, intvec_top + 1);
+ mpic->isu_size, &mpic_host_ops,
+ intvec_top + 1);
/*
* FIXME: The code leaks the MPIC object and mappings here; this
--
1.7.7.3
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