From: Christoffer Dall <christoffer.dall@linaro.org>
Date: Thu, 2 Oct 2014 07:29:59 +0000 (+0200)
Subject: ARM: bL_switcher: do not hardcode GIC IDs in the code
X-Git-Tag: firefly_0821_release~3680^2~36^2~17^2^2~16
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0284d57fefb977c52748176308d30d30a148d24c;p=firefly-linux-kernel-4.4.55.git

ARM: bL_switcher: do not hardcode GIC IDs in the code

Currently, GIC IDs are hardcoded making the code dependent on the 4+4 b.L
configuration.  Let's allow for GIC IDs to be discovered upon switcher
initialization to support other b.L configurations such as the 1+1 one,
or 2+3 as on the VExpress TC2.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
(cherry picked from commit ed96762e3241f57aa812977cf1920d3ee0363f4d)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 4f5741df74e7..dbd26dae2e4b 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -667,6 +667,27 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 #endif
 
 #ifdef CONFIG_BL_SWITCHER
+/*
+ * gic_get_cpu_id - get the CPU interface ID for the specified CPU
+ *
+ * @cpu: the logical CPU number to get the GIC ID for.
+ *
+ * Return the CPU interface ID for the given logical CPU number,
+ * or -1 if the CPU number is too large or the interface ID is
+ * unknown (more than one bit set).
+ */
+int gic_get_cpu_id(unsigned int cpu)
+{
+	unsigned int cpu_bit;
+
+	if (cpu >= NR_GIC_CPU_IF)
+		return -1;
+	cpu_bit = gic_cpu_map[cpu];
+	if (cpu_bit & (cpu_bit - 1))
+		return -1;
+	return __ffs(cpu_bit);
+}
+
 /*
  * gic_migrate_target - migrate IRQs to another CPU interface
  *
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index 40bfcac95940..2d7d47e8dfaf 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -75,6 +75,7 @@ static inline void gic_init(unsigned int nr, int start,
 	gic_init_bases(nr, start, dist, cpu, 0, NULL);
 }
 
+int gic_get_cpu_id(unsigned int cpu);
 void gic_migrate_target(unsigned int new_cpu_id);
 
 #endif /* __ASSEMBLY */