From ed96762e3241f57aa812977cf1920d3ee0363f4d Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 5 Jul 2012 21:33:26 -0400 Subject: [PATCH] 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 --- arch/arm/common/bL_switcher.c | 14 +++++++++++++- drivers/irqchip/irq-gic.c | 21 +++++++++++++++++++++ include/linux/irqchip/arm-gic.h | 1 + 3 files changed, 35 insertions(+), 1 deletion(-) diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c index 50e95d89..1c2e5bc 100644 --- a/arch/arm/common/bL_switcher.c +++ b/arch/arm/common/bL_switcher.c @@ -110,6 +110,8 @@ static int bL_switchpoint(unsigned long _arg) * Generic switcher interface */ +static unsigned int bL_gic_id[MAX_CPUS_PER_CLUSTER][MAX_NR_CLUSTERS]; + /* * bL_switch_to - Switch to a specific cluster for the current CPU * @new_cluster_id: the ID of the cluster to switch to. @@ -159,7 +161,7 @@ static int bL_switch_to(unsigned int new_cluster_id) this_cpu = smp_processor_id(); /* redirect GIC's SGIs to our counterpart */ - gic_migrate_target(cpuid + ib_cluster*4); + gic_migrate_target(bL_gic_id[cpuid][ib_cluster]); /* * Raise a SGI on the inbound CPU to make sure it doesn't stall @@ -332,6 +334,16 @@ static int __init bL_switcher_halve_cpus(void) cluster = (cpu_logical_map(i) >> 8) & 0xff; if (cpumask_test_cpu(cpu, &common_mask)) { + /* Let's take note of the GIC ID for this CPU */ + int gic_id = gic_get_cpu_id(i); + if (gic_id < 0) { + pr_err("%s: bad GIC ID for CPU %d\n", __func__, i); + return -EINVAL; + } + bL_gic_id[cpu][cluster] = gic_id; + pr_info("GIC ID for CPU %u cluster %u is %u\n", + cpu, cluster, gic_id); + /* * We keep only those logical CPUs which number * is equal to their physical CPU number. This is diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 268874a..3862cb5 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -668,6 +668,27 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) #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 * * @new_cpu_id: the CPU target ID to migrate IRQs to diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h index 40bfcac..2d7d47e 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 */ -- 2.7.4