[PATCH v3 1/8] irqchip/mips-gic: Only register IPI domain when SMP is enabled

[Samuel Holland <samuel@xxxxxxxxxxxx>]

The MIPS GIC irqchip driver may be selected in a uniprocessor
configuration, but it unconditionally registers an IPI domain.

Limit the part of the driver dealing with IPIs to only be compiled when
GENERIC_IRQ_IPI is enabled, which corresponds to an SMP configuration.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
---

Changes in v3:
 - New patch to fix build errors in uniprocessor MIPS configs

 drivers/irqchip/Kconfig        |  3 +-
 drivers/irqchip/irq-mips-gic.c | 80 +++++++++++++++++++++++-----------
 2 files changed, 56 insertions(+), 27 deletions(-)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 1f23a6be7d88..d26a4ff7c99f 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -322,7 +322,8 @@ config KEYSTONE_IRQ
 
 config MIPS_GIC
        bool
-       select GENERIC_IRQ_IPI
+       select GENERIC_IRQ_IPI if SMP
+       select IRQ_DOMAIN_HIERARCHY
        select MIPS_CM
 
 config INGENIC_IRQ
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index ff89b36267dd..8a9efb6ae587 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -52,13 +52,15 @@ static DEFINE_PER_CPU_READ_MOSTLY(unsigned 
long[GIC_MAX_LONGS], pcpu_masks);
 
 static DEFINE_SPINLOCK(gic_lock);
 static struct irq_domain *gic_irq_domain;
-static struct irq_domain *gic_ipi_domain;
 static int gic_shared_intrs;
 static unsigned int gic_cpu_pin;
 static unsigned int timer_cpu_pin;
 static struct irq_chip gic_level_irq_controller, gic_edge_irq_controller;
+
+#ifdef CONFIG_GENERIC_IRQ_IPI
 static DECLARE_BITMAP(ipi_resrv, GIC_MAX_INTRS);
 static DECLARE_BITMAP(ipi_available, GIC_MAX_INTRS);
+#endif /* CONFIG_GENERIC_IRQ_IPI */
 
 static struct gic_all_vpes_chip_data {
        u32     map;
@@ -472,9 +474,11 @@ static int gic_irq_domain_map(struct irq_domain *d, 
unsigned int virq,
        u32 map;
 
        if (hwirq >= GIC_SHARED_HWIRQ_BASE) {
+#ifdef CONFIG_GENERIC_IRQ_IPI
                /* verify that shared irqs don't conflict with an IPI irq */
                if (test_bit(GIC_HWIRQ_TO_SHARED(hwirq), ipi_resrv))
                        return -EBUSY;
+#endif /* CONFIG_GENERIC_IRQ_IPI */
 
                err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
                                                    &gic_level_irq_controller,
@@ -567,6 +571,8 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
        .map = gic_irq_domain_map,
 };
 
+#ifdef CONFIG_GENERIC_IRQ_IPI
+
 static int gic_ipi_domain_xlate(struct irq_domain *d, struct device_node 
*ctrlr,
                                const u32 *intspec, unsigned int intsize,
                                irq_hw_number_t *out_hwirq,
@@ -670,6 +676,48 @@ static const struct irq_domain_ops gic_ipi_domain_ops = {
        .match = gic_ipi_domain_match,
 };
 
+static int gic_register_ipi_domain(struct device_node *node)
+{
+       struct irq_domain *gic_ipi_domain;
+       unsigned int v[2], num_ipis;
+
+       gic_ipi_domain = irq_domain_add_hierarchy(gic_irq_domain,
+                                                 IRQ_DOMAIN_FLAG_IPI_PER_CPU,
+                                                 GIC_NUM_LOCAL_INTRS + 
gic_shared_intrs,
+                                                 node, &gic_ipi_domain_ops, 
NULL);
+       if (!gic_ipi_domain) {
+               pr_err("Failed to add IPI domain");
+               return -ENXIO;
+       }
+
+       irq_domain_update_bus_token(gic_ipi_domain, DOMAIN_BUS_IPI);
+
+       if (node &&
+           !of_property_read_u32_array(node, "mti,reserved-ipi-vectors", v, 
2)) {
+               bitmap_set(ipi_resrv, v[0], v[1]);
+       } else {
+               /*
+                * Reserve 2 interrupts per possible CPU/VP for use as IPIs,
+                * meeting the requirements of arch/mips SMP.
+                */
+               num_ipis = 2 * num_possible_cpus();
+               bitmap_set(ipi_resrv, gic_shared_intrs - num_ipis, num_ipis);
+       }
+
+       bitmap_copy(ipi_available, ipi_resrv, GIC_MAX_INTRS);
+
+       return 0;
+}
+
+#else /* !CONFIG_GENERIC_IRQ_IPI */
+
+static inline int gic_register_ipi_domain(struct device_node *node)
+{
+       return 0;
+}
+
+#endif /* !CONFIG_GENERIC_IRQ_IPI */
+
 static int gic_cpu_startup(unsigned int cpu)
 {
        /* Enable or disable EIC */
@@ -688,11 +736,12 @@ static int gic_cpu_startup(unsigned int cpu)
 static int __init gic_of_init(struct device_node *node,
                              struct device_node *parent)
 {
-       unsigned int cpu_vec, i, gicconfig, v[2], num_ipis;
+       unsigned int cpu_vec, i, gicconfig;
        unsigned long reserved;
        phys_addr_t gic_base;
        struct resource res;
        size_t gic_len;
+       int ret;
 
        /* Find the first available CPU vector. */
        i = 0;
@@ -780,30 +829,9 @@ static int __init gic_of_init(struct device_node *node,
                return -ENXIO;
        }
 
-       gic_ipi_domain = irq_domain_add_hierarchy(gic_irq_domain,
-                                                 IRQ_DOMAIN_FLAG_IPI_PER_CPU,
-                                                 GIC_NUM_LOCAL_INTRS + 
gic_shared_intrs,
-                                                 node, &gic_ipi_domain_ops, 
NULL);
-       if (!gic_ipi_domain) {
-               pr_err("Failed to add IPI domain");
-               return -ENXIO;
-       }
-
-       irq_domain_update_bus_token(gic_ipi_domain, DOMAIN_BUS_IPI);
-
-       if (node &&
-           !of_property_read_u32_array(node, "mti,reserved-ipi-vectors", v, 
2)) {
-               bitmap_set(ipi_resrv, v[0], v[1]);
-       } else {
-               /*
-                * Reserve 2 interrupts per possible CPU/VP for use as IPIs,
-                * meeting the requirements of arch/mips SMP.
-                */
-               num_ipis = 2 * num_possible_cpus();
-               bitmap_set(ipi_resrv, gic_shared_intrs - num_ipis, num_ipis);
-       }
-
-       bitmap_copy(ipi_available, ipi_resrv, GIC_MAX_INTRS);
+       ret = gic_register_ipi_domain(node);
+       if (ret)
+               return ret;
 
        board_bind_eic_interrupt = &gic_bind_eic_interrupt;
 
-- 
2.35.1