The interrupt-map in an interrupt nexus is quite a tricky property: Each
entry contains five fields, the size of four of those depending on some
*-cells entries from two different nodes. This is even hard to validate
in a .dts file, especially when the associated interrupt controller is
described in a separate (included) file.
Add checks to validate those entries, by:
- Checking some basic properties of the interrupt nexus node.
- Checking that a map entry contains at least enough cells to point to
the associated interrupt controller.
- Checking that the phandle points to an actual interrupt controller.
- Checking that there are enough entries to describe an interrupt in
that interrupt controller's domain.
If each iteration passes and we exhaust exactly all the cells in the
interrupt-map property, the check passes.
Report errors on the way, and abort the check if that happens.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
checks.c | 86 +++++++++++++++++++++++++++++++++++++++++++++
tests/bad-interrupt-map.dts | 21 +++++++++++
tests/run_tests.sh | 2 ++
3 files changed, 109 insertions(+)
create mode 100644 tests/bad-interrupt-map.dts
diff --git a/checks.c b/checks.c
index 4b3c486..12518db 100644
--- a/checks.c
+++ b/checks.c
@@ -924,6 +924,90 @@ static void check_pci_device_reg(struct check *c, struct dt_info *dti, struct no
}
WARNING(pci_device_reg, check_pci_device_reg, NULL, ®_format, &pci_bridge);
+static void check_interrupt_map(struct check *c, struct dt_info *dti,
+ struct node *node)
+{
+ struct property *map = get_property(node, "interrupt-map");
+ struct property *prop;
+ int i, cells, irq_cells;
+
+ /* We are only interested in interrupt nexus nodes. */
+ if (!map)
+ return;
+
+ if (map->val.len % sizeof(cell_t)) {
+ FAIL_PROP(c, dti, node, map, "invalid length of interrupt-map");
+ return;
+ }
+ cells = map->val.len / sizeof(cell_t);
+
+ prop = get_property(node, "#interrupt-cells");
+ if (!prop) {
+ FAIL(c, dti, node, "missing #interrupt-cells in nexus\n");
+ return;
+ }
+ irq_cells = propval_cell(prop);
+
+ for (i = 0; i < cells;) {
+ int phandle_idx = i + node_addr_cells(node) + irq_cells;
+ cell_t intc_phandle, intc_irq_cells, intc_addr_cells;
+ struct node *intc = NULL;
+
+ if (phandle_idx + 1 >= cells) {
+ FAIL_PROP(c, dti, node, map,
+ "insufficient cells for interrupt-map entry");
+ return;
+ }
+ intc_phandle = propval_cell_n(map, phandle_idx);
+ /* Avoid the assert in get_node_by_phandle(). */
+ if (intc_phandle != 0)
+ intc = get_node_by_phandle(dti->dt, intc_phandle);
+ if (!intc) {
+ FAIL_PROP(c, dti, node, map,
+ "invalid phandle for interrupt-map entry");
+ return;
+ }
+
+ prop = get_property(intc, "interrupt-controller");
+ if (!prop) {
+ FAIL_PROP(c,dti, node, map,
+ "interrupt-map phandle does not point to interrupt controller");
+ return;
+ }
+
+ prop = get_property(intc, "#address-cells");
+ if (!prop) {
+ FAIL_PROP(c,dti, node, map,
+ "interrupt-controller misses #address-cells property");
+ /*
+ * Linux treats non-existing #address-cells in the
+ * interrupt parent as 0, and not 2, as the spec
+ * suggests. Deal with that, but print the warning,
+ * since we should have an explicit #a-c = 0 in the
+ * controller node in this case.
+ */
+ intc_addr_cells = 0;
+ } else
+ intc_addr_cells = propval_cell(prop);
+
+ prop = get_property(intc, "#interrupt-cells");
+ if (!prop) {
+ FAIL_PROP(c,dti, node, map,
+ "interrupt-controller misses #interrupt-cells property");
+ return;
+ }
+ intc_irq_cells = propval_cell(prop);
+
+ if (phandle_idx + intc_addr_cells + intc_irq_cells >= cells) {
+ FAIL_PROP(c, dti, node, map,
+ "insufficient cells for interrupt-map entry");
+ return;
+ }
+ i = phandle_idx + 1 + intc_addr_cells + intc_irq_cells;
+ }
+}
+WARNING(interrupt_map, check_interrupt_map, NULL);
+
static const struct bus_type simple_bus = {
.name = "simple-bus",
};
@@ -1792,6 +1876,8 @@ static struct check *check_table[] = {
&pci_device_reg,
&pci_device_bus_num,
+ &interrupt_map,
+
&simple_bus_bridge,
&simple_bus_reg,
diff --git a/tests/bad-interrupt-map.dts b/tests/bad-interrupt-map.dts
new file mode 100644
index 0000000..cf9618f
--- /dev/null
+++ b/tests/bad-interrupt-map.dts
@@ -0,0 +1,21 @@
+/dts-v1/;
+
+/ {
+ intc: interrupt-controller {
+ interrupt-controller;
+ #address-cells = <2>;
+ #interrupt-cells = <3>;
+ };
+
+ nexus-node {
+ #address-cells = <1>;
+ #interrupt-cells = <1>;
+/*
+ * The cells after the phandle are the address in the interrupt controller's
+ * domain. This here encodes 0 cells , but the actual number is 2 above.
+ */
+ interrupt-map = <0 0 &intc 1 42 4>,
+ <0 1 &intc 1 43 4>,
+ <0 2 &intc 1 44 4>;
+ };
+};
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index eccb85d..aec92fb 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -732,6 +732,8 @@ dtc_tests () {
check_tests "$SRCDIR/pci-bridge-bad1.dts" pci_bridge
check_tests "$SRCDIR/pci-bridge-bad2.dts" pci_bridge
+ check_tests "$SRCDIR/bad-interrupt-map.dts" interrupt_map
+
check_tests "$SRCDIR/unit-addr-simple-bus-reg-mismatch.dts" simple_bus_reg
check_tests "$SRCDIR/unit-addr-simple-bus-compatible.dts" simple_bus_reg
--
2.14.1
