[3/4] RISC-V: Support nr_cpus command line option.

Commit Message

Atish Patra April 24, 2019, 9:48 p.m. UTC

If nr_cpus command line option is set, maximum possible cpu should be
set to that value.

Signed-off-by: Atish Patra <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
---
 arch/riscv/kernel/smpboot.  |  0
 arch/riscv/kernel/smpboot.c | 10 +++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/kernel/smpboot.

Comments

Sudeep Holla April 25, 2019, 9:59 a.m. UTC | #1

On Wed, Apr 24, 2019 at 02:48:00PM -0700, Atish Patra wrote:
> If nr_cpus command line option is set, maximum possible cpu should be
> set to that value.
> 
> Signed-off-by: Atish Patra <[e-mail]>
> Reviewed-by: Christoph Hellwig <[e-mail]>

FWIW,

Reviewed-by: Sudeep Holla <[e-mail]>

--
Regards,
Sudeep

Patch

diff --git a/arch/riscv/kernel/smpboot. b/arch/riscv/kernel/smpboot.
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index a8ad200581aa..7a0b62252524 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -84,11 +84,19 @@  void __init setup_smp(void)
 		}
 
 		cpuid_to_hartid_map(cpuid) = hart;
-		set_cpu_possible(cpuid, true);
 		cpuid++;
 	}
 
 	BUG_ON(!found_boot_cpu);
+
+	if (cpuid > nr_cpu_ids)
+		pr_warn("Total number of cpus [%d] is greater than nr_cpus option value [%d]\n",
+			cpuid, nr_cpu_ids);
+
+	for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
+		if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID)
+			set_cpu_possible(cpuid, true);
+	}
 }
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)