Commit ed96762e authored by Nicolas Pitre's avatar Nicolas Pitre
Browse files

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: default avatarNicolas Pitre <nico@linaro.org>
parent 9797a0e9

arch/arm/common/bL_switcher.c

+13 −1
Original line number Diff line number Diff line
@@ -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

drivers/irqchip/irq-gic.c

+21 −0
Original line number Diff line number Diff line
@@ -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

 *

include/linux/irqchip/arm-gic.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */