Re: [PATCH] openrisc: use device tree to determine present cpus
From: Jan Henrik Weinstock
Date: Sat Jan 30 2021 - 06:01:09 EST
Hi Stafford, Geert,
thanks for your feedback. I have made the following changes to the patch:
1. use for_each_of_cpu_node
2. possible_cpus is now what is in the devicetree, up to NR_CPUS
3. present_cpus is now all possible cpus, up to max_cpus
Signed-off-by: Jan Henrik Weinstock <jan.weinstock@xxxxxxxxxxxxxx>
---
arch/openrisc/kernel/smp.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/arch/openrisc/kernel/smp.c b/arch/openrisc/kernel/smp.c
index 29c82ef2e..83cbf43d4 100644
--- a/arch/openrisc/kernel/smp.c
+++ b/arch/openrisc/kernel/smp.c
@@ -16,6 +16,7 @@
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/irq.h>
+#include <linux/of.h>
#include <asm/cpuinfo.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
@@ -60,22 +61,32 @@ void __init smp_prepare_boot_cpu(void)
void __init smp_init_cpus(void)
{
- int i;
+ struct device_node* cpu;
+ u32 cpu_id;
- for (i = 0; i < NR_CPUS; i++)
- set_cpu_possible(i, true);
+ for_each_of_cpu_node(cpu) {
+ if (of_property_read_u32(cpu, "reg", &cpu_id)) {
+ pr_warn("%s missing reg property", cpu->full_name);
+ continue;
+ }
+
+ if (cpu_id < NR_CPUS)
+ set_cpu_possible(cpu_id, true);
+ }
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
- int i;
+ unsigned int cpu;
/*
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
- for (i = 0; i < max_cpus; i++)
- set_cpu_present(i, true);
+ for_each_possible_cpu(cpu) {
+ if (cpu < max_cpus)
+ set_cpu_present(cpu, true);
+ }
}
void __init smp_cpus_done(unsigned int max_cpus)
--
2.17.1
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