[PATCH] irqchip/gic: Fix EOImode settiing non-DT/ACPI systems

[Marc Zyngier]

Non-DT/ACPI systems call directly into the GIC driver at init time.
Since 0b996fd35957 ("irqchip/GIC: Convert to EOImode == 1"), this
breaks old non firmware-driven platforms, as the driver only
works out the capability of the platform on the DT/ACPI paths.

Fix this thinko by forcing EOImode==0 on non-DT platforms,
which are not capable of supporting a hypervisor anyway.

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
 drivers/irqchip/irq-gic.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 72bf81b..e6b7ed5 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -993,7 +993,7 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
 	.xlate = gic_irq_domain_xlate,
 };
 
-void __init gic_init_bases(unsigned int gic_nr, int irq_start,
+static void __init __gic_init_bases(unsigned int gic_nr, int irq_start,
 			   void __iomem *dist_base, void __iomem *cpu_base,
 			   u32 percpu_offset, struct device_node *node)
 {
@@ -1103,6 +1103,19 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 	gic_pm_init(gic);
 }
 
+void __init gic_init_bases(unsigned int gic_nr, int irq_start,
+			   void __iomem *dist_base, void __iomem *cpu_base,
+			   u32 percpu_offset, struct device_node *node)
+{
+	/*
+	 * Non-DT/ACPI systems won't run a hypervisor, so let's not
+	 * bother with these...
+	 */
+	static_key_slow_dec(&supports_deactivate);
+	__gic_init_bases(gic_nr, irq_start, dist_base, cpu_base,
+			 percpu_offset, node);
+}
+
 #ifdef CONFIG_OF
 static int gic_cnt __initdata;
 
@@ -1137,7 +1150,7 @@ gic_of_init(struct device_node *node, struct device_node *parent)
 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
 		percpu_offset = 0;
 
-	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
+	__gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
 	if (!gic_cnt)
 		gic_init_physaddr(node);
 
@@ -1265,7 +1278,7 @@ gic_v2_acpi_init(struct acpi_table_header *table)
 	 * as default IRQ domain to allow for GSI registration and GSI to IRQ
 	 * number translation (see acpi_register_gsi() and acpi_gsi_to_irq()).
 	 */
-	gic_init_bases(0, -1, dist_base, cpu_base, 0, NULL);
+	__gic_init_bases(0, -1, dist_base, cpu_base, 0, NULL);
 	irq_set_default_host(gic_data[0].domain);
 
 	acpi_irq_model = ACPI_IRQ_MODEL_GIC;
-- 
2.1.4

Can you give it a whirl? It makes the PB-A8 emulation work correctly
here.

> I wonder how it comes that you get a console output from qemu, but I don't.
> Did you use multi_v7_defconfig or some other configuration ?

I enable earlyprintk, which makes debugging much easier...  Of course,
earlyprintk comes with its own set of issues (it is the absolute
negation of any form of multiplatform kernel), which is why it is
disabled by default.

Thanks,

	M. 
-- 
Without deviation from the norm, progress is not possible.
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