From: Salil Mehta <salil.mehta@huawei.com>
To: <linux-arm-kernel@lists.infradead.org>
Cc: mark.rutland@arm.com, peter.maydell@linaro.org, gshan@redhat.com,
kvm@vger.kernel.org, mst@redhat.com, catalin.marinas@arm.com,
linuxarm@huawei.com, linux-kernel@vger.kernel.org,
will@kernel.org, Xiongfeng Wang <wangxiongfeng2@huawei.com>,
lorenzo.pieralisi@arm.com, maz@kernel.org, david@redhat.com,
drjones@redhat.com, andre.przywara@arm.com,
mehta.salil.lnk@gmail.com, richard.henderson@linaro.org,
eric.auger@redhat.com, qemu-arm@nongnu.org, imammedo@redhat.com,
Salil Mehta <salil.mehta@huawei.com>,
christoffer.dall@arm.com, james.morse@arm.com,
sudeep.holla@arm.com, pbonzini@redhat.com
Subject: [PATCH RFC 2/4] arm64: kernel: Bound the total(present+disabled) cpus with nr_cpu_ids
Date: Thu, 25 Jun 2020 14:37:55 +0100 [thread overview]
Message-ID: <20200625133757.22332-3-salil.mehta@huawei.com> (raw)
In-Reply-To: <20200625133757.22332-1-salil.mehta@huawei.com>
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 <salil.mehta@huawei.com>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
---
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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next prev parent reply other threads:[~2020-06-25 13:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-25 13:37 [PATCH RFC 0/4] Changes to Support *Virtual* CPU Hotplug for ARM64 Salil Mehta
2020-06-25 13:37 ` [PATCH RFC 1/4] arm64: kernel: Handle disabled[(+)present] cpus in MADT/GICC during init Salil Mehta
2020-06-25 13:37 ` Salil Mehta [this message]
2020-06-25 13:37 ` [PATCH RFC 3/4] arm64: kernel: Init cpu operations for all possible vcpus Salil Mehta
2020-06-25 13:37 ` [PATCH RFC 4/4] arm64: kernel: Arch specific ACPI hooks(like logical cpuid<->hwid etc.) Salil Mehta
2020-07-07 9:52 ` [PATCH RFC 0/4] Changes to Support *Virtual* CPU Hotplug for ARM64 Salil Mehta
2020-07-08 12:29 ` James Morse
2020-07-08 16:11 ` Salil Mehta
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