irqchip/irq-bcm7038-l1: Gate use of CPU logical map to MIPS

The use of the cpu_logical_map[] array is only relevant for MIPS based
platform where this driver is used as a first level interrupt controller
and contains multiple register groups to map with an associated CPU.

On ARM/ARM64 based systems this interrupt controller is present and used
as a second level interrupt controller hanging off the ARM GIC. That
copy of the interrupt controller contains a single group, resulting in
the intc->cpus[] array to be of size 1.

Things happened to work in that case because we install that interrupt
controller as a chained handler which does not allow it to be affine to
any CPU but the boot CPU which happens to be 0, therefore we never
de-reference past intc->cpus[] but with the current code in place, we do
leave a chance of de-referencing the array past its bounds.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211020184859.2705451-5-f.fainelli@gmail.com

diff --git a/drivers/irqchip/irq-bcm7038-l1.c b/drivers/irqchip/irq-bcm7038-l1.c
index 14caf32dc23e41ac74af607dbe610be7744ce5d8..3c4e348c661e32e81a78f1ad9d985d9bd04b5868 100644 (file)
--- a/drivers/irqchip/irq-bcm7038-l1.c
+++ b/drivers/irqchip/irq-bcm7038-l1.c
@@ -28,9 +28,6 @@
 #include <linux/irqchip.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/syscore_ops.h>
-#ifdef CONFIG_ARM
-#include <asm/smp_plat.h>
-#endif
 
 #define IRQS_PER_WORD          32
 #define REG_BYTES_PER_IRQ_WORD (sizeof(u32) * 4)
@@ -127,7 +124,7 @@ static void bcm7038_l1_irq_handle(struct irq_desc *desc)
        struct irq_chip *chip = irq_desc_get_chip(desc);
        unsigned int idx;
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
        cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
 #else
        cpu = intc->cpus[0];
@@ -301,7 +298,7 @@ static int bcm7038_l1_suspend(void)
        u32 val;
 
        /* Wakeup interrupt should only come from the boot cpu */
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
        boot_cpu = cpu_logical_map(0);
 #else
        boot_cpu = 0;
@@ -325,7 +322,7 @@ static void bcm7038_l1_resume(void)
        struct bcm7038_l1_chip *intc;
        int boot_cpu, word;
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
        boot_cpu = cpu_logical_map(0);
 #else
        boot_cpu = 0;