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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: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Eugeniy Paltsev 2018-02-23 19:41:54 +03:00 committed by Vineet Gupta
parent f3205de98d
commit a29a252754
1 changed files with 40 additions and 10 deletions
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50
arch/arc/kernel/smp.c
View File

@ -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)