From: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
To: linux-pm@vger.kernel.org, loongarch@lists.linux.dev,
linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-riscv@lists.infradead.org, kvmarm@lists.linux.dev,
x86@kernel.org, linux-csky@vger.kernel.org,
linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-parisc@vger.kernel.org
Cc: Salil Mehta <salil.mehta@huawei.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
jianyong.wu@arm.com, justin.he@arm.com,
James Morse <james.morse@arm.com>,
Huacai Chen <chenhuacai@kernel.org>,
WANG Xuerui <kernel@xen0n.name>
Subject: [PATCH 17/21] LoongArch: Switch over to GENERIC_CPU_DEVICES
Date: Tue, 21 Nov 2023 13:45:17 +0000 [thread overview]
Message-ID: <E1r5R41-00Ct04-Bg@rmk-PC.armlinux.org.uk> (raw)
In-Reply-To: <ZVyz/Ve5pPu8AWoA@shell.armlinux.org.uk>
From: James Morse <james.morse@arm.com>
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be
overridden by the arch code, switch over to this to allow common code
to choose when the register_cpu() call is made.
This allows topology_init() to be removed.
This is an intermediate step to the logic being moved to drivers/acpi,
where GENERIC_CPU_DEVICES will do the work when booting with acpi=off.
This is a subtle change. Originally:
- on boot, topology_init() would have marked present CPUs that
io_master() is true for as hotplug-incapable.
- if a CPU is hotplugged that is an io_master(), it can later be
hot-unplugged.
The new behaviour is that any CPU that io_master() is true for will
now always be marked as hotplug-incapable, thus even if it was
hotplugged, it can no longer be hot-unplugged.
This patch also has the effect of moving the registration of CPUs from
subsys to driver core initialisation, prior to any initcalls running.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
Changes since RFC v2:
* Explain the change in behaviour in the patch description
(highlighted by Jonathan Cameron - thanks.) Add note about
initialisation order change.
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/kernel/topology.c | 29 ++---------------------------
2 files changed, 3 insertions(+), 27 deletions(-)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 331becb2cb4f..15d05dd2b7f3 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -72,6 +72,7 @@ config LOONGARCH
select GENERIC_CLOCKEVENTS
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
+ select GENERIC_CPU_DEVICES
select GENERIC_ENTRY
select GENERIC_GETTIMEOFDAY
select GENERIC_IOREMAP if !ARCH_IOREMAP
diff --git a/arch/loongarch/kernel/topology.c b/arch/loongarch/kernel/topology.c
index ae860fe81536..7dfb46c68f58 100644
--- a/arch/loongarch/kernel/topology.c
+++ b/arch/loongarch/kernel/topology.c
@@ -10,20 +10,13 @@
#include <acpi/processor.h>
-static DEFINE_PER_CPU(struct cpu, cpu_devices);
-
#ifdef CONFIG_HOTPLUG_CPU
int arch_register_cpu(int cpu)
{
- int ret;
struct cpu *c = &per_cpu(cpu_devices, cpu);
- c->hotpluggable = 1;
- ret = register_cpu(c, cpu);
- if (ret < 0)
- pr_warn("register_cpu %d failed (%d)\n", cpu, ret);
-
- return ret;
+ c->hotpluggable = !io_master(cpu);
+ return register_cpu(c, cpu);
}
void arch_unregister_cpu(int cpu)
@@ -34,21 +27,3 @@ void arch_unregister_cpu(int cpu)
unregister_cpu(c);
}
#endif
-
-static int __init topology_init(void)
-{
- int i, ret;
-
- for_each_present_cpu(i) {
- struct cpu *c = &per_cpu(cpu_devices, i);
-
- c->hotpluggable = !io_master(i);
- ret = register_cpu(c, i);
- if (ret < 0)
- pr_warn("topology_init: register_cpu %d failed (%d)\n", i, ret);
- }
-
- return 0;
-}
-
-subsys_initcall(topology_init);
--
2.30.2
next prev parent reply other threads:[~2023-11-21 13:45 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-21 13:43 [PATCH 00/21] Initial cleanups for vCPU hotplug Russell King (Oracle)
2023-11-21 13:43 ` [PATCH 01/21] arch_topology: Make register_cpu_capacity_sysctl() tolerant to late CPUs Russell King
2023-11-30 16:46 ` Jonathan Cameron
2023-12-01 10:45 ` Thomas Gleixner
2023-11-21 13:44 ` [PATCH 02/21] x86: intel_epb: Don't rely on link order Russell King
2023-11-22 20:12 ` Rafael J. Wysocki
2023-11-21 13:44 ` [PATCH 03/21] x86/topology: remove arch_*register_cpu() exports Russell King (Oracle)
2023-11-30 16:48 ` Jonathan Cameron
2023-11-21 13:44 ` [PATCH 04/21] Loongarch: " Russell King (Oracle)
2023-11-30 16:48 ` Jonathan Cameron
2023-11-21 13:44 ` [PATCH 05/21] ACPI: Move ACPI_HOTPLUG_CPU to be disabled on arm64 and riscv Russell King
2023-11-22 20:16 ` Rafael J. Wysocki
2023-11-30 16:49 ` Jonathan Cameron
2023-11-21 13:44 ` [PATCH 06/21] drivers: base: Use present CPUs in GENERIC_CPU_DEVICES Russell King
2023-11-21 13:44 ` [PATCH 07/21] drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overridden Russell King
2023-11-30 16:50 ` Jonathan Cameron
2023-11-21 13:44 ` [PATCH 08/21] drivers: base: Implement weak arch_unregister_cpu() Russell King
2023-11-30 16:50 ` Jonathan Cameron
2023-12-01 3:47 ` Gavin Shan
2023-12-01 11:06 ` Thomas Gleixner
2023-11-21 13:44 ` [PATCH 09/21] drivers: base: add arch_cpu_is_hotpluggable() Russell King (Oracle)
2023-11-30 16:51 ` Jonathan Cameron
2023-12-01 3:47 ` Gavin Shan
2023-11-21 13:44 ` [PATCH 10/21] drivers: base: Move cpu_dev_init() after node_dev_init() Russell King
2023-11-30 16:52 ` Jonathan Cameron
2023-12-01 3:48 ` Gavin Shan
2023-11-21 13:44 ` [PATCH 11/21] drivers: base: Print a warning instead of panic() when register_cpu() fails Russell King
2023-11-30 16:53 ` Jonathan Cameron
2023-12-01 3:49 ` Gavin Shan
2023-11-21 13:44 ` [PATCH 12/21] arm64: setup: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu() Russell King
2023-11-30 16:54 ` Jonathan Cameron
2023-12-11 13:20 ` Will Deacon
2023-11-21 13:44 ` [PATCH 13/21] arm64: convert to arch_cpu_is_hotpluggable() Russell King (Oracle)
2023-11-30 16:54 ` Jonathan Cameron
2023-12-11 13:21 ` Will Deacon
2023-11-21 13:45 ` [PATCH 14/21] x86/topology: Switch over to GENERIC_CPU_DEVICES Russell King
2023-11-30 16:56 ` Jonathan Cameron
2023-11-21 13:45 ` [PATCH 15/21] x86/topology: use weak version of arch_unregister_cpu() Russell King (Oracle)
2023-11-30 16:57 ` Jonathan Cameron
2023-11-21 13:45 ` [PATCH 16/21] x86/topology: convert to use arch_cpu_is_hotpluggable() Russell King (Oracle)
2023-11-30 16:55 ` Jonathan Cameron
2023-11-21 13:45 ` Russell King [this message]
2023-11-30 16:57 ` [PATCH 17/21] LoongArch: Switch over to GENERIC_CPU_DEVICES Jonathan Cameron
2023-11-21 13:45 ` [PATCH 18/21] LoongArch: Use the __weak version of arch_unregister_cpu() Russell King
2023-11-21 13:45 ` [PATCH 19/21] LoongArch: convert to use arch_cpu_is_hotpluggable() Russell King (Oracle)
2023-11-30 16:55 ` Jonathan Cameron
2023-11-21 13:45 ` [PATCH 20/21] riscv: Switch over to GENERIC_CPU_DEVICES Russell King
2023-11-22 20:05 ` Samuel Holland
2023-11-21 13:45 ` [PATCH 21/21] riscv: convert to use arch_cpu_is_hotpluggable() Russell King (Oracle)
2023-11-22 20:08 ` Samuel Holland
2023-11-30 16:55 ` Jonathan Cameron
2023-12-01 8:53 ` [PATCH 00/21] Initial cleanups for vCPU hotplug Thomas Gleixner
2023-12-01 11:25 ` Thomas Gleixner
2023-12-01 12:28 ` Greg Kroah-Hartman
2023-12-01 16:09 ` Thomas Gleixner
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