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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>
hifive-unleashed-5.1
Nicolas Pitre 2012-07-05 21:33:26 -04:00
parent 9797a0e95e
commit ed96762e32
3 changed files with 35 additions and 1 deletions
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14
arch/arm/common/bL_switcher.c
View File

@ -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

21
drivers/irqchip/irq-gic.c
View File

@ -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
*

1
include/linux/irqchip/arm-gic.h
View File

@ -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 */