From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
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, kvmarm@lists.linux.dev,
x86@kernel.org, Russell King <linux@armlinux.org.uk>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Miguel Luis <miguel.luis@oracle.com>,
James Morse <james.morse@arm.com>,
Salil Mehta <salil.mehta@huawei.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
linuxarm@huawei.com, justin.he@arm.com, jianyong.wu@arm.com
Subject: Re: [PATCH v7 01/16] ACPI: processor: Simplify initial onlining to use same path for cold and hotplug
Date: Mon, 22 Apr 2024 20:46:30 +0200 [thread overview]
Message-ID: <CAJZ5v0hrXHbv8JGydxwD1PP_M1GOm040=+OTDFLcpy3bmzf24A@mail.gmail.com> (raw)
In-Reply-To: <20240418135412.14730-2-Jonathan.Cameron@huawei.com>
On Thu, Apr 18, 2024 at 3:54 PM Jonathan Cameron
<Jonathan.Cameron@huawei.com> wrote:
>
> Separate code paths, combined with a flag set in acpi_processor.c to
> indicate a struct acpi_processor was for a hotplugged CPU ensured that
> per CPU data was only set up the first time that a CPU was initialized.
> This appears to be unnecessary as the paths can be combined by letting
> the online logic also handle any CPUs online at the time of driver load.
>
> Motivation for this change, beyond simplification, is that ARM64
> virtual CPU HP uses the same code paths for hotplug and cold path in
> acpi_processor.c so had no easy way to set the flag for hotplug only.
> Removing this necessity will enable ARM64 vCPU HP to reuse the existing
> code paths.
>
> Leave noisy pr_info() in place but update it to not state the CPU
> was hotplugged.
>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
LGTM, so
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> v7: No change.
> v6: New patch.
> RFT: I have very limited test resources for x86 and other
> architectures that may be affected by this change.
> ---
> drivers/acpi/acpi_processor.c | 1 -
> drivers/acpi/processor_driver.c | 44 ++++++++++-----------------------
> include/acpi/processor.h | 2 +-
> 3 files changed, 14 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
> index 7a0dd35d62c9..7fc924aeeed0 100644
> --- a/drivers/acpi/acpi_processor.c
> +++ b/drivers/acpi/acpi_processor.c
> @@ -216,7 +216,6 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr)
> * gets online for the first time.
> */
> pr_info("CPU%d has been hot-added\n", pr->id);
> - pr->flags.need_hotplug_init = 1;
>
> out:
> cpus_write_unlock();
> diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
> index 67db60eda370..55782eac3ff1 100644
> --- a/drivers/acpi/processor_driver.c
> +++ b/drivers/acpi/processor_driver.c
> @@ -33,7 +33,6 @@ MODULE_AUTHOR("Paul Diefenbaugh");
> MODULE_DESCRIPTION("ACPI Processor Driver");
> MODULE_LICENSE("GPL");
>
> -static int acpi_processor_start(struct device *dev);
> static int acpi_processor_stop(struct device *dev);
>
> static const struct acpi_device_id processor_device_ids[] = {
> @@ -47,7 +46,6 @@ static struct device_driver acpi_processor_driver = {
> .name = "processor",
> .bus = &cpu_subsys,
> .acpi_match_table = processor_device_ids,
> - .probe = acpi_processor_start,
> .remove = acpi_processor_stop,
> };
>
> @@ -115,12 +113,10 @@ static int acpi_soft_cpu_online(unsigned int cpu)
> * CPU got physically hotplugged and onlined for the first time:
> * Initialize missing things.
> */
> - if (pr->flags.need_hotplug_init) {
> + if (!pr->flags.previously_online) {
> int ret;
>
> - pr_info("Will online and init hotplugged CPU: %d\n",
> - pr->id);
> - pr->flags.need_hotplug_init = 0;
> + pr_info("Will online and init CPU: %d\n", pr->id);
> ret = __acpi_processor_start(device);
> WARN(ret, "Failed to start CPU: %d\n", pr->id);
> } else {
> @@ -167,9 +163,6 @@ static int __acpi_processor_start(struct acpi_device *device)
> if (!pr)
> return -ENODEV;
>
> - if (pr->flags.need_hotplug_init)
> - return 0;
> -
> result = acpi_cppc_processor_probe(pr);
> if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
> dev_dbg(&device->dev, "CPPC data invalid or not present\n");
> @@ -185,32 +178,21 @@ static int __acpi_processor_start(struct acpi_device *device)
>
> status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
> acpi_processor_notify, device);
> - if (ACPI_SUCCESS(status))
> - return 0;
> + if (!ACPI_SUCCESS(status)) {
> + result = -ENODEV;
> + goto err_thermal_exit;
> + }
> + pr->flags.previously_online = 1;
>
> - result = -ENODEV;
> - acpi_processor_thermal_exit(pr, device);
> + return 0;
>
> +err_thermal_exit:
> + acpi_processor_thermal_exit(pr, device);
> err_power_exit:
> acpi_processor_power_exit(pr);
> return result;
> }
>
> -static int acpi_processor_start(struct device *dev)
> -{
> - struct acpi_device *device = ACPI_COMPANION(dev);
> - int ret;
> -
> - if (!device)
> - return -ENODEV;
> -
> - /* Protect against concurrent CPU hotplug operations */
> - cpu_hotplug_disable();
> - ret = __acpi_processor_start(device);
> - cpu_hotplug_enable();
> - return ret;
> -}
> -
> static int acpi_processor_stop(struct device *dev)
> {
> struct acpi_device *device = ACPI_COMPANION(dev);
> @@ -279,9 +261,9 @@ static int __init acpi_processor_driver_init(void)
> if (result < 0)
> return result;
>
> - result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
> - "acpi/cpu-drv:online",
> - acpi_soft_cpu_online, NULL);
> + result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> + "acpi/cpu-drv:online",
> + acpi_soft_cpu_online, NULL);
> if (result < 0)
> goto err;
> hp_online = result;
> diff --git a/include/acpi/processor.h b/include/acpi/processor.h
> index 3f34ebb27525..e6f6074eadbf 100644
> --- a/include/acpi/processor.h
> +++ b/include/acpi/processor.h
> @@ -217,7 +217,7 @@ struct acpi_processor_flags {
> u8 has_lpi:1;
> u8 power_setup_done:1;
> u8 bm_rld_set:1;
> - u8 need_hotplug_init:1;
> + u8 previously_online:1;
> };
>
> struct acpi_processor {
> --
next prev parent reply other threads:[~2024-04-22 18:46 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 13:53 [PATCH v7 00/16] ACPI/arm64: add support for virtual cpu hotplug Jonathan Cameron
2024-04-18 13:53 ` [PATCH v7 01/16] ACPI: processor: Simplify initial onlining to use same path for cold and hotplug Jonathan Cameron
2024-04-22 18:46 ` Rafael J. Wysocki [this message]
2024-04-23 6:18 ` Hanjun Guo
2024-04-26 9:23 ` Gavin Shan
2024-04-18 13:53 ` [PATCH v7 02/16] cpu: Do not warn on arch_register_cpu() returning -EPROBE_DEFER Jonathan Cameron
2024-04-23 6:22 ` Hanjun Guo
2024-04-26 9:20 ` Gavin Shan
2024-04-18 13:53 ` [PATCH v7 03/16] ACPI: processor: Drop duplicated check on _STA (enabled + present) Jonathan Cameron
2024-04-22 18:48 ` Rafael J. Wysocki
2024-04-23 6:49 ` Hanjun Guo
2024-04-23 9:31 ` Rafael J. Wysocki
2024-04-23 11:13 ` Hanjun Guo
2024-04-26 9:24 ` Gavin Shan
2024-04-18 13:54 ` [PATCH v7 04/16] ACPI: processor: Move checks and availability of acpi_processor earlier Jonathan Cameron
2024-04-22 18:56 ` Rafael J. Wysocki
2024-04-24 16:53 ` Jonathan Cameron
2024-04-23 11:53 ` Hanjun Guo
2024-04-24 17:18 ` Jonathan Cameron
2024-04-25 1:20 ` Hanjun Guo
2024-04-18 13:54 ` [PATCH v7 05/16] ACPI: processor: Add acpi_get_processor_handle() helper Jonathan Cameron
2024-04-22 18:59 ` Rafael J. Wysocki
2024-04-26 9:15 ` Gavin Shan
2024-04-18 13:54 ` [PATCH v7 06/16] ACPI: processor: Register deferred CPUs from acpi_processor_get_info() Jonathan Cameron
2024-04-22 19:02 ` Rafael J. Wysocki
2024-04-23 11:58 ` Hanjun Guo
2024-04-26 9:18 ` Gavin Shan
2024-04-18 13:54 ` [PATCH v7 07/16] ACPI: scan: switch to flags for acpi_scan_check_and_detach() Jonathan Cameron
2024-04-22 19:05 ` Rafael J. Wysocki
2024-04-23 12:02 ` Hanjun Guo
2024-04-26 9:25 ` Gavin Shan
2024-04-18 13:54 ` [PATCH v7 08/16] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug Jonathan Cameron
2024-04-22 19:10 ` Rafael J. Wysocki
2024-04-23 12:06 ` Hanjun Guo
2024-04-26 11:48 ` Jonathan Cameron
2024-04-18 13:54 ` [PATCH v7 09/16] arm64: acpi: Move get_cpu_for_acpi_id() to a header Jonathan Cameron
2024-04-22 10:46 ` Jonathan Cameron
2024-04-23 12:10 ` Hanjun Guo
2024-04-18 13:54 ` [PATCH v7 10/16] irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc() Jonathan Cameron
2024-04-22 10:39 ` Jonathan Cameron
2024-04-18 13:54 ` [PATCH v7 11/16] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Jonathan Cameron
2024-04-22 10:40 ` Jonathan Cameron
2024-04-23 12:01 ` Marc Zyngier
2024-04-24 12:54 ` Jonathan Cameron
2024-04-24 15:33 ` Marc Zyngier
2024-04-24 16:35 ` Salil Mehta
2024-04-24 17:08 ` Jonathan Cameron
2024-04-25 10:23 ` Jonathan Cameron
2024-04-25 12:31 ` Jonathan Cameron
2024-04-25 15:00 ` Jonathan Cameron
2024-04-25 16:55 ` Jonathan Cameron
2024-04-26 12:41 ` Marc Zyngier
2024-04-25 9:28 ` Jonathan Cameron
2024-04-25 9:56 ` Jonathan Cameron
2024-04-25 10:13 ` Jonathan Cameron
2024-04-18 13:54 ` [PATCH v7 12/16] arm64: psci: Ignore DENIED CPUs Jonathan Cameron
2024-04-22 10:44 ` Jonathan Cameron
2024-04-26 9:36 ` Gavin Shan
2024-04-26 9:57 ` Jonathan Cameron
2024-04-18 13:54 ` [PATCH v7 13/16] arm64: arch_register_cpu() variant to check if an ACPI handle is now available Jonathan Cameron
2024-04-18 13:54 ` [PATCH v7 14/16] arm64: Kconfig: Enable hotplug CPU on arm64 if ACPI_PROCESSOR is enabled Jonathan Cameron
2024-04-24 17:24 ` Jonathan Cameron
2024-04-18 13:54 ` [PATCH v7 15/16] arm64: document virtual CPU hotplug's expectations Jonathan Cameron
2024-04-18 13:54 ` [PATCH v7 16/16] cpumask: Add enabled cpumask for present CPUs that can be brought online Jonathan Cameron
2024-04-18 19:50 ` [PATCH v7 00/16] ACPI/arm64: add support for virtual cpu hotplug Rafael J. Wysocki
2024-04-22 19:16 ` Rafael J. Wysocki
2024-04-19 15:39 ` Miguel Luis
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