irqchip/gic-v3: Ignore disabled ITS nodes

On some platforms there's an ITS available but it's not enabled
because reading or writing the registers is denied by the
firmware. In fact, reading or writing them will cause the system
to reset. We could remove the node from DT in such a case, but
it's better to skip nodes that are marked as "disabled" in DT so
that we can describe the hardware that exists and use the status
property to indicate how the firmware has configured things.

Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

4 files changed, 8 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index 14a8c0a7e095..25a98de5cfb2 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -132,6 +132,8 @@ static int __init its_pci_of_msi_init(void)
 
         for (np = of_find_matching_node(NULL, its_device_id); np;
              np = of_find_matching_node(np, its_device_id)) {
+                if (!of_device_is_available(np))
+                        continue;
                 if (!of_property_read_bool(np, "msi-controller"))
                         continue;
 
diff --git a/drivers/irqchip/irq-gic-v3-its-platform-msi.c b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
index 833a90fe33ae..8881a053c173 100644
--- a/drivers/irqchip/irq-gic-v3-its-platform-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-platform-msi.c
@@ -154,6 +154,8 @@ static void __init its_pmsi_of_init(void)
 
         for (np = of_find_matching_node(NULL, its_device_id); np;
              np = of_find_matching_node(np, its_device_id)) {
+                if (!of_device_is_available(np))
+                        continue;
                 if (!of_property_read_bool(np, "msi-controller"))
                         continue;
 
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 06f025fd5726..1d3056f53747 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3314,6 +3314,8 @@ static int __init its_of_probe(struct device_node *node)
 
         for (np = of_find_matching_node(node, its_device_id); np;
              np = of_find_matching_node(np, its_device_id)) {
+                if (!of_device_is_available(np))
+                        continue;
                 if (!of_property_read_bool(np, "msi-controller")) {
                         pr_warn("%pOF: no msi-controller property, ITS ignored\n",
                                 np);
diff --git a/drivers/staging/fsl-mc/bus/irq-gic-v3-its-fsl-mc-msi.c b/drivers/staging/fsl-mc/bus/irq-gic-v3-its-fsl-mc-msi.c
index 5064d5ddf581..fc2013aade51 100644
--- a/drivers/staging/fsl-mc/bus/irq-gic-v3-its-fsl-mc-msi.c
+++ b/drivers/staging/fsl-mc/bus/irq-gic-v3-its-fsl-mc-msi.c
@@ -73,6 +73,8 @@ static int __init its_fsl_mc_msi_init(void)
 
         for (np = of_find_matching_node(NULL, its_device_id); np;
              np = of_find_matching_node(np, its_device_id)) {
+                if (!of_device_is_available(np))
+                        continue;
                 if (!of_property_read_bool(np, "msi-controller"))
                         continue;