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Commit a29a2527 authored by Eugeniy Paltsev's avatar Eugeniy Paltsev Committed by Vineet Gupta
Browse files

ARC: setup cpu possible mask according to possible-cpus dts property 



As we have option in u-boot to set CPU mask for running linux,
we want to pass information to kernel about CPU cores should
be brought up. So we patch kernel dtb in u-boot to set
possible-cpus property.

This also allows us to have correctly setuped MCIP debug mask.

Signed-off-by: default avatarEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent f3205de9

arch/arc/kernel/smp.c

+40 −10
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/reboot.h>

#include <linux/irqdomain.h>

#include <linux/export.h>

#include <linux/of_fdt.h>



#include <asm/processor.h>

#include <asm/setup.h>
@@ -47,6 +48,42 @@ void __init smp_prepare_boot_cpu(void) 
{

}



static int __init arc_get_cpu_map(const char *name, struct cpumask *cpumask)

{

	unsigned long dt_root = of_get_flat_dt_root();

	const char *buf;



	buf = of_get_flat_dt_prop(dt_root, name, NULL);

	if (!buf)

		return -EINVAL;



	if (cpulist_parse(buf, cpumask))

		return -EINVAL;



	return 0;

}



/*

 * Read from DeviceTree and setup cpu possible mask. If there is no

 * "possible-cpus" property in DeviceTree pretend all [0..NR_CPUS-1] exist.

 */

static void __init arc_init_cpu_possible(void)

{

	struct cpumask cpumask;



	if (arc_get_cpu_map("possible-cpus", &cpumask)) {

		pr_warn("Failed to get possible-cpus from dtb, pretending all %u cpus exist\n",

			NR_CPUS);



		cpumask_setall(&cpumask);

	}



	if (!cpumask_test_cpu(0, &cpumask))

		panic("Master cpu (cpu[0]) is missed in cpu possible mask!");



	init_cpu_possible(&cpumask);

}



/*

 * Called from setup_arch() before calling setup_processor()

 *
@@ -58,10 +95,7 @@ void __init smp_prepare_boot_cpu(void) 
 */

void __init smp_init_cpus(void)

{

	unsigned int i;



	for (i = 0; i < NR_CPUS; i++)

		set_cpu_possible(i, true);

	arc_init_cpu_possible();



	if (plat_smp_ops.init_early_smp)

		plat_smp_ops.init_early_smp();
@@ -70,16 +104,12 @@ void __init smp_init_cpus(void) 
/* called from init ( ) =>  process 1 */

void __init smp_prepare_cpus(unsigned int max_cpus)

{

	int i;



	/*

	 * if platform didn't set the present map already, do it now

	 * boot cpu is set to present already by init/main.c

	 */

	if (num_present_cpus() <= 1) {

		for (i = 0; i < max_cpus; i++)

			set_cpu_present(i, true);

	}

	if (num_present_cpus() <= 1)

		init_cpu_present(cpu_possible_mask);

}



void __init smp_cpus_done(unsigned int max_cpus)