ARC: [intc-*] Do a domain lookup in primary handler for hwirq -> linux virq

The primary interrupt handler arch_do_IRQ() was passing hwirq as linux
virq to core code. This was fragile and worked so far as we only had legacy/linear
domains.

This came out of a rant by Marc Zyngier.
http://lists.infradead.org/pipermail/linux-snps-arc/2015-December/000298.html

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index ae39434..4f1482a 100644 (file)
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -31,6 +31,7 @@ config ARC
        select HAVE_MOD_ARCH_SPECIFIC if ARC_DW2_UNWIND
        select HAVE_OPROFILE
        select HAVE_PERF_EVENTS
+       select HANDLE_DOMAIN_IRQ
        select IRQ_DOMAIN
        select MODULES_USE_ELF_RELA
        select NO_BOOTMEM

diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
index 9425263..592cc97 100644 (file)
--- a/arch/arc/kernel/intc-arcv2.c
+++ b/arch/arc/kernel/intc-arcv2.c
@@ -137,21 +137,24 @@ static const struct irq_domain_ops arcv2_irq_ops = {
        .map = arcv2_irq_map,
 };
 
-static struct irq_domain *root_domain;
 
 static int __init
 init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
 {
+       struct irq_domain *root_domain;
+
        if (parent)
                panic("DeviceTree incore intc not a root irq controller\n");
 
        root_domain = irq_domain_add_legacy(intc, NR_CPU_IRQS, 0, 0,
                                            &arcv2_irq_ops, NULL);
-
        if (!root_domain)
                panic("root irq domain not avail\n");
 
-       /* with this we don't need to export root_domain */
+       /*
+        * Needed for primary domain lookup to succeed
+        * This is a primary irqchip, and can never have a parent
+        */
        irq_set_default_host(root_domain);
 
        return 0;

diff --git a/arch/arc/kernel/intc-compact.c b/arch/arc/kernel/intc-compact.c
index d31bc64..48a8b24 100644 (file)
--- a/arch/arc/kernel/intc-compact.c
+++ b/arch/arc/kernel/intc-compact.c
@@ -97,21 +97,23 @@ static const struct irq_domain_ops arc_intc_domain_ops = {
        .map = arc_intc_domain_map,
 };
 
-static struct irq_domain *root_domain;
-
 static int __init
 init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
 {
+       struct irq_domain *root_domain;
+
        if (parent)
                panic("DeviceTree incore intc not a root irq controller\n");
 
        root_domain = irq_domain_add_legacy(intc, NR_CPU_IRQS, 0, 0,
                                            &arc_intc_domain_ops, NULL);
-
        if (!root_domain)
                panic("root irq domain not avail\n");
 
-       /* with this we don't need to export root_domain */
+       /*
+        * Needed for primary domain lookup to succeed
+        * This is a primary irqchip, and can never have a parent
+        */
        irq_set_default_host(root_domain);
 
        return 0;

diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
index fb6dede..538b36a 100644 (file)
--- a/arch/arc/kernel/irq.c
+++ b/arch/arc/kernel/irq.c
@@ -41,12 +41,7 @@ void __init init_IRQ(void)
  * "C" Entry point for any ARC ISR, called from low level vector handler
  * @irq is the vector number read from ICAUSE reg of on-chip intc
  */
-void arch_do_IRQ(unsigned int irq, struct pt_regs *regs)
+void arch_do_IRQ(unsigned int hwirq, struct pt_regs *regs)
 {
-       struct pt_regs *old_regs = set_irq_regs(regs);
-
-       irq_enter();
-       generic_handle_irq(irq);
-       irq_exit();
-       set_irq_regs(old_regs);
+       handle_domain_irq(NULL, hwirq, regs);
 }