irqchip/gic: Drop support for secondary GIC in non-DT systems

We do not have any in-tree platform with this pathological setup,
and only a single system (Cavium's cns3xxx) isn't DT aware.

Let's drop the secondary GIC support for now, until we remove
the above horror altogether.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

3 files changed, 18 insertions, 32 deletions

diff --git a/arch/arm/mach-cns3xxx/core.c b/arch/arm/mach-cns3xxx/core.c
index 7d5a44a06648..f676592d8402 100644
--- a/arch/arm/mach-cns3xxx/core.c
+++ b/arch/arm/mach-cns3xxx/core.c
@@ -90,7 +90,7 @@ void __init cns3xxx_map_io(void)
 /* used by entry-macro.S */
 void __init cns3xxx_init_irq(void)
 {
-        gic_init(0, 29, IOMEM(CNS3XXX_TC11MP_GIC_DIST_BASE_VIRT),
+        gic_init(IOMEM(CNS3XXX_TC11MP_GIC_DIST_BASE_VIRT),
                  IOMEM(CNS3XXX_TC11MP_GIC_CPU_BASE_VIRT));
 }
 
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index ba2a37a27a54..fd3110c171ba 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1089,11 +1089,10 @@ static void gic_init_chip(struct gic_chip_data *gic, struct device *dev,
 #endif
 }
 
-static int gic_init_bases(struct gic_chip_data *gic, int irq_start,
+static int gic_init_bases(struct gic_chip_data *gic,
                           struct fwnode_handle *handle)
 {
-        irq_hw_number_t hwirq_base;
-        int gic_irqs, irq_base, ret;
+        int gic_irqs, ret;
 
         if (IS_ENABLED(CONFIG_GIC_NON_BANKED) && gic->percpu_offset) {
                 /* Frankein-GIC without banked registers... */
@@ -1145,28 +1144,21 @@ static int gic_init_bases(struct gic_chip_data *gic, int irq_start,
         } else {                /* Legacy support */
                 /*
                  * For primary GICs, skip over SGIs.
-                 * For secondary GICs, skip over PPIs, too.
+                 * No secondary GIC support whatsoever.
                  */
-                if (gic == &gic_data[0] && (irq_start & 31) > 0) {
-                        hwirq_base = 16;
-                        if (irq_start != -1)
-                                irq_start = (irq_start & ~31) + 16;
-                } else {
-                        hwirq_base = 32;
-                }
+                int irq_base;
 
-                gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
+                gic_irqs -= 16; /* calculate # of irqs to allocate */
 
-                irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
+                irq_base = irq_alloc_descs(16, 16, gic_irqs,
                                            numa_node_id());
                 if (irq_base < 0) {
-                        WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
-                             irq_start);
-                        irq_base = irq_start;
+                        WARN(1, "Cannot allocate irq_descs @ IRQ16, assuming pre-allocated\n");
+                        irq_base = 16;
                 }
 
                 gic->domain = irq_domain_add_legacy(NULL, gic_irqs, irq_base,
-                                        hwirq_base, &gic_irq_domain_ops, gic);
+                                                    16, &gic_irq_domain_ops, gic);
         }
 
         if (WARN_ON(!gic->domain)) {
@@ -1195,7 +1187,6 @@ error:
 }
 
 static int __init __gic_init_bases(struct gic_chip_data *gic,
-                                   int irq_start,
                                    struct fwnode_handle *handle)
 {
         char *name;
@@ -1231,32 +1222,28 @@ static int __init __gic_init_bases(struct gic_chip_data *gic,
                 gic_init_chip(gic, NULL, name, false);
         }
 
-        ret = gic_init_bases(gic, irq_start, handle);
+        ret = gic_init_bases(gic, handle);
         if (ret)
                 kfree(name);
 
         return ret;
 }
 
-void __init gic_init(unsigned int gic_nr, int irq_start,
-                     void __iomem *dist_base, void __iomem *cpu_base)
+void __init gic_init(void __iomem *dist_base, void __iomem *cpu_base)
 {
         struct gic_chip_data *gic;
 
-        if (WARN_ON(gic_nr >= CONFIG_ARM_GIC_MAX_NR))
-                return;
-
         /*
          * Non-DT/ACPI systems won't run a hypervisor, so let's not
          * bother with these...
          */
         static_branch_disable(&supports_deactivate_key);
 
-        gic = &gic_data[gic_nr];
+        gic = &gic_data[0];
         gic->raw_dist_base = dist_base;
         gic->raw_cpu_base = cpu_base;
 
-        __gic_init_bases(gic, irq_start, NULL);
+        __gic_init_bases(gic, NULL);
 }
 
 static void gic_teardown(struct gic_chip_data *gic)
@@ -1399,7 +1386,7 @@ int gic_of_init_child(struct device *dev, struct gic_chip_data **gic, int irq)
         if (ret)
                 return ret;
 
-        ret = gic_init_bases(*gic, -1, &dev->of_node->fwnode);
+        ret = gic_init_bases(*gic, &dev->of_node->fwnode);
         if (ret) {
                 gic_teardown(*gic);
                 return ret;
@@ -1459,7 +1446,7 @@ gic_of_init(struct device_node *node, struct device_node *parent)
         if (gic_cnt == 0 && !gic_check_eoimode(node, &gic->raw_cpu_base))
                 static_branch_disable(&supports_deactivate_key);
 
-        ret = __gic_init_bases(gic, -1, &node->fwnode);
+        ret = __gic_init_bases(gic, &node->fwnode);
         if (ret) {
                 gic_teardown(gic);
                 return ret;
@@ -1650,7 +1637,7 @@ static int __init gic_v2_acpi_init(struct acpi_subtable_header *header,
                 return -ENOMEM;
         }
 
-        ret = __gic_init_bases(gic, -1, domain_handle);
+        ret = __gic_init_bases(gic, domain_handle);
         if (ret) {
                 pr_err("Failed to initialise GIC\n");
                 irq_domain_free_fwnode(domain_handle);
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index 626179077bb0..0f049b384ccd 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -158,8 +158,7 @@ int gic_of_init_child(struct device *dev, struct gic_chip_data **gic, int irq);
  * Legacy platforms not converted to DT yet must use this to init
  * their GIC
  */
-void gic_init(unsigned int nr, int start,
-              void __iomem *dist , void __iomem *cpu);
+void gic_init(void __iomem *dist , void __iomem *cpu);
 
 int gicv2m_init(struct fwnode_handle *parent_handle,
                 struct irq_domain *parent);