1 files changed, 52 insertions, 7 deletions

diff --git a/drivers/irqchip/irq-vic.c b/drivers/irqchip/irq-vic.c
index 8e21ae0bab46..6002942a231c 100644
--- a/drivers/irqchip/irq-vic.c
+++ b/drivers/irqchip/irq-vic.c
@@ -57,6 +57,7 @@
 
 /**
  * struct vic_device - VIC PM device
+ * @parent_irq: The parent IRQ number of the VIC if cascaded, or 0.
  * @irq: The IRQ number for the base of the VIC.
  * @base: The register base for the VIC.
  * @valid_sources: A bitmask of valid interrupts
@@ -224,6 +225,17 @@ static int handle_one_vic(struct vic_device *vic, struct pt_regs *regs)
         return handled;
 }
 
+static void vic_handle_irq_cascaded(unsigned int irq, struct irq_desc *desc)
+{
+        u32 stat, hwirq;
+        struct vic_device *vic = irq_desc_get_handler_data(desc);
+
+        while ((stat = readl_relaxed(vic->base + VIC_IRQ_STATUS))) {
+                hwirq = ffs(stat) - 1;
+                generic_handle_irq(irq_find_mapping(vic->domain, hwirq));
+        }
+}
+
 /*
  * Keep iterating over all registered VIC's until there are no pending
  * interrupts.
@@ -246,6 +258,7 @@ static struct irq_domain_ops vic_irqdomain_ops = {
 /**
  * vic_register() - Register a VIC.
  * @base: The base address of the VIC.
+ * @parent_irq: The parent IRQ if cascaded, else 0.
  * @irq: The base IRQ for the VIC.
  * @valid_sources: bitmask of valid interrupts
  * @resume_sources: bitmask of interrupts allowed for resume sources.
@@ -257,7 +270,8 @@ static struct irq_domain_ops vic_irqdomain_ops = {
  *
  * This also configures the IRQ domain for the VIC.
  */
-static void __init vic_register(void __iomem *base, unsigned int irq,
+static void __init vic_register(void __iomem *base, unsigned int parent_irq,
+                                unsigned int irq,
                                 u32 valid_sources, u32 resume_sources,
                                 struct device_node *node)
 {
@@ -273,15 +287,25 @@ static void __init vic_register(void __iomem *base, unsigned int irq,
         v->base = base;
         v->valid_sources = valid_sources;
         v->resume_sources = resume_sources;
-        v->irq = irq;
         set_handle_irq(vic_handle_irq);
         vic_id++;
+
+        if (parent_irq) {
+                irq_set_handler_data(parent_irq, v);
+                irq_set_chained_handler(parent_irq, vic_handle_irq_cascaded);
+        }
+
         v->domain = irq_domain_add_simple(node, fls(valid_sources), irq,
                                           &vic_irqdomain_ops, v);
         /* create an IRQ mapping for each valid IRQ */
         for (i = 0; i < fls(valid_sources); i++)
                 if (valid_sources & (1 << i))
                         irq_create_mapping(v->domain, i);
+        /* If no base IRQ was passed, figure out our allocated base */
+        if (irq)
+                v->irq = irq;
+        else
+                v->irq = irq_find_mapping(v->domain, 0);
 }
 
 static void vic_ack_irq(struct irq_data *d)
@@ -409,10 +433,10 @@ static void __init vic_init_st(void __iomem *base, unsigned int irq_start,
                 writel(32, base + VIC_PL190_DEF_VECT_ADDR);
         }
 
-        vic_register(base, irq_start, vic_sources, 0, node);
+        vic_register(base, 0, irq_start, vic_sources, 0, node);
 }
 
-void __init __vic_init(void __iomem *base, int irq_start,
+void __init __vic_init(void __iomem *base, int parent_irq, int irq_start,
                               u32 vic_sources, u32 resume_sources,
                               struct device_node *node)
 {
@@ -449,7 +473,7 @@ void __init __vic_init(void __iomem *base, int irq_start,
 
         vic_init2(base);
 
-        vic_register(base, irq_start, vic_sources, resume_sources, node);
+        vic_register(base, parent_irq, irq_start, vic_sources, resume_sources, node);
 }
 
 /**
@@ -462,7 +486,28 @@ void __init __vic_init(void __iomem *base, int irq_start,
 void __init vic_init(void __iomem *base, unsigned int irq_start,
                      u32 vic_sources, u32 resume_sources)
 {
-        __vic_init(base, irq_start, vic_sources, resume_sources, NULL);
+        __vic_init(base, 0, irq_start, vic_sources, resume_sources, NULL);
+}
+
+/**
+ * vic_init_cascaded() - initialise a cascaded vectored interrupt controller
+ * @base: iomem base address
+ * @parent_irq: the parent IRQ we're cascaded off
+ * @irq_start: starting interrupt number, must be muliple of 32
+ * @vic_sources: bitmask of interrupt sources to allow
+ * @resume_sources: bitmask of interrupt sources to allow for resume
+ *
+ * This returns the base for the new interrupts or negative on error.
+ */
+int __init vic_init_cascaded(void __iomem *base, unsigned int parent_irq,
+                              u32 vic_sources, u32 resume_sources)
+{
+        struct vic_device *v;
+
+        v = &vic_devices[vic_id];
+        __vic_init(base, parent_irq, 0, vic_sources, resume_sources, NULL);
+        /* Return out acquired base */
+        return v->irq;
 }
 
 #ifdef CONFIG_OF
@@ -485,7 +530,7 @@ int __init vic_of_init(struct device_node *node, struct device_node *parent)
         /*
          * Passing 0 as first IRQ makes the simple domain allocate descriptors
          */
-        __vic_init(regs, 0, interrupt_mask, wakeup_mask, node);
+        __vic_init(regs, 0, 0, interrupt_mask, wakeup_mask, node);
 
         return 0;
 }