[PATCH RFC 2/4] arm64: kernel: Bound the total(present+disabled) cpus with nr_cpu_ids
From: Salil Mehta <hidden>
Date: 2020-06-25 13:44:12
Also in:
kvm, lkml, qemu-arm
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Bound the total number of identified cpus(including disabled cpus) by maximum allowed limit by the kernel. Max value is either specified as part of the kernel parameters 'nr_cpus' or specified during compile time using CONFIG_NR_CPUS. Signed-off-by: Salil Mehta <redacted> Signed-off-by: Xiongfeng Wang <redacted> --- arch/arm64/kernel/smp.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 51a707928302..864ccd3da419 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c@@ -513,6 +513,7 @@ static int __init smp_cpu_setup(int cpu) } static bool bootcpu_valid __initdata; +static bool cpus_clipped __initdata = false; static unsigned int cpu_count = 1; static unsigned int disabled_cpu_count;
@@ -536,6 +537,11 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor) unsigned int total_cpu_count = disabled_cpu_count + cpu_count; u64 hwid = processor->arm_mpidr; + if (total_cpu_count > nr_cpu_ids) { + cpus_clipped = true; + return; + } + if (!(processor->flags & ACPI_MADT_ENABLED)) { #ifndef CONFIG_ACPI_HOTPLUG_CPU pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid);
@@ -569,9 +575,6 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor) return; } - if (cpu_count >= NR_CPUS) - return; - /* map the logical cpu id to cpu MPIDR */ cpu_logical_map(total_cpu_count) = hwid;
@@ -688,8 +691,10 @@ static void __init of_parse_and_init_cpus(void) continue; } - if (cpu_count >= NR_CPUS) + if (cpu_count >= NR_CPUS) { + cpus_clipped = true; goto next; + } pr_debug("cpu logical map 0x%llx\n", hwid); cpu_logical_map(cpu_count) = hwid;
@@ -710,6 +715,7 @@ static void __init of_parse_and_init_cpus(void) */ void __init smp_init_cpus(void) { + unsigned int total_cpu_count = disabled_cpu_count + cpu_count; int i; if (acpi_disabled)
@@ -717,9 +723,9 @@ void __init smp_init_cpus(void) else acpi_parse_and_init_cpus(); - if (cpu_count > nr_cpu_ids) + if (cpus_clipped) pr_warn("Number of cores (%d) exceeds configured maximum of %u - clipping\n", - cpu_count, nr_cpu_ids); + total_cpu_count, nr_cpu_ids); if (!bootcpu_valid) { pr_err("missing boot CPU MPIDR, not enabling secondaries\n");
--
2.17.1
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