From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 695FC9476; Wed, 8 May 2024 08:44:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715157864; cv=none; b=eWsJrTOETcxfyvZBZRLzfDJ+S8/Qp2nD2zcWPvwXIY029nR7SnfbM2oYpFuQ8io5XqB+OfDXNNLFjGk4Sczi7O4sMVhnWfPVO3Lrc2+jmkx27svcn0rA11g1mwFi6oRrRh8idJr6xUmdRqcWEfxD8g0QU1HydoBygf0DDxoMbck= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715157864; c=relaxed/simple; bh=T5zecpj4li0OuIWBMVUt5WCfBkgXJbSbJgxIbR51vqs=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SRswTxxyLC8rm9PIKjNZp+4cp1VyJ6qoFVNYchE1oZIF5QCfKiXwcpwl1PyLAexLWSFVud7jiqq8OsKCeg4HZji0EmJ5Ughbcj9x1K2hpiZpNUuICauGyl129Q6kxIxuZBMBGeKALhVGBK+C7qKT/y6MOKMQ5w5/wu/oR5Knrb4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4VZ7sK1b83z6K6Kl; Wed, 8 May 2024 16:41:09 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 44CD0140B54; Wed, 8 May 2024 16:44:14 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Wed, 8 May 2024 09:44:13 +0100 Date: Wed, 8 May 2024 09:44:11 +0100 From: Jonathan Cameron To: "Rafael J. Wysocki" CC: Thomas Gleixner , Peter Zijlstra , , , , , , , , , Russell King , Miguel Luis , James Morse , Salil Mehta , Jean-Philippe Brucker , Catalin Marinas , Will Deacon , Marc Zyngier , Hanjun Guo , "Gavin Shan" , Ingo Molnar , Borislav Petkov , Dave Hansen , , , Subject: Re: [PATCH v9 06/19] ACPI: processor: Move checks and availability of acpi_processor earlier Message-ID: <20240508094411.00001b92@Huawei.com> In-Reply-To: References: <20240430142434.10471-1-Jonathan.Cameron@huawei.com> <20240430142434.10471-7-Jonathan.Cameron@huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To lhrpeml500005.china.huawei.com (7.191.163.240) On Tue, 7 May 2024 21:04:26 +0200 "Rafael J. Wysocki" wrote: > On Tue, Apr 30, 2024 at 4:27=E2=80=AFPM Jonathan Cameron > wrote: > > > > Make the per_cpu(processors, cpu) entries available earlier so that > > they are available in arch_register_cpu() as ARM64 will need access > > to the acpi_handle to distinguish between acpi_processor_add() > > and earlier registration attempts (which will fail as _STA cannot > > be checked). > > > > Reorder the remove flow to clear this per_cpu() after > > arch_unregister_cpu() has completed, allowing it to be used in > > there as well. > > > > Note that on x86 for the CPU hotplug case, the pr->id prior to > > acpi_map_cpu() may be invalid. Thus the per_cpu() structures > > must be initialized after that call or after checking the ID > > is valid (not hotplug path). > > > > Signed-off-by: Jonathan Cameron =20 >=20 > Acked-by: Rafael J. Wysocki >=20 > One nit below. Thanks. Given timing, this is looking like 6.11 material. I'll tidy this up and post a v10 in a couple of weeks (so around rc1 time). Maybe we'll pick up some more tags for the ARM specific bits in the meantime. Thanks for all your help! Jonathan >=20 > > --- > > v9: Add back a blank line accidentally removed in code move. > > Fix up error returns so that the new cleanup in processor_add() > > is triggered on detection of the bios bug. > > Combined with the previous 2 patches, should solve the leak > > that Gavin identified. > > --- > > drivers/acpi/acpi_processor.c | 80 +++++++++++++++++++++-------------- > > 1 file changed, 49 insertions(+), 31 deletions(-) > > > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processo= r.c > > index 16e36e55a560..4a79b42d649e 100644 > > --- a/drivers/acpi/acpi_processor.c > > +++ b/drivers/acpi/acpi_processor.c > > @@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {} > > #endif /* CONFIG_X86 */ > > > > /* Initialization */ > > +static DEFINE_PER_CPU(void *, processor_device_array); > > + > > +static bool acpi_processor_set_per_cpu(struct acpi_processor *pr, > > + struct acpi_device *device) > > +{ > > + BUG_ON(pr->id >=3D nr_cpu_ids); > > + > > + /* > > + * Buggy BIOS check. > > + * ACPI id of processors can be reported wrongly by the BIOS. > > + * Don't trust it blindly > > + */ > > + if (per_cpu(processor_device_array, pr->id) !=3D NULL && > > + per_cpu(processor_device_array, pr->id) !=3D device) { > > + dev_warn(&device->dev, > > + "BIOS reported wrong ACPI id %d for the proces= sor\n", > > + pr->id); > > + return false; > > + } > > + /* > > + * processor_device_array is not cleared on errors to allow bug= gy BIOS > > + * checks. > > + */ > > + per_cpu(processor_device_array, pr->id) =3D device; > > + per_cpu(processors, pr->id) =3D pr; > > + > > + return true; > > +} > > + > > #ifdef CONFIG_ACPI_HOTPLUG_CPU > > -static int acpi_processor_hotadd_init(struct acpi_processor *pr) > > +static int acpi_processor_hotadd_init(struct acpi_processor *pr, > > + struct acpi_device *device) > > { > > int ret; > > > > @@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_= processor *pr) > > if (ret) > > goto out; > > > > + if (!acpi_processor_set_per_cpu(pr, device)) { > > + ret =3D -EINVAL; > > + acpi_unmap_cpu(pr->id); > > + goto out; > > + } > > + > > ret =3D arch_register_cpu(pr->id); > > if (ret) { > > + /* Leave the processor device array in place to detect = buggy bios */ > > + per_cpu(processors, pr->id) =3D NULL; > > acpi_unmap_cpu(pr->id); > > goto out; > > } > > @@ -217,7 +255,8 @@ static int acpi_processor_hotadd_init(struct acpi_p= rocessor *pr) > > return ret; > > } > > #else > > -static inline int acpi_processor_hotadd_init(struct acpi_processor *pr) > > +static inline int acpi_processor_hotadd_init(struct acpi_processor *pr, > > + struct acpi_device *device) > > { > > return -ENODEV; > > } > > @@ -316,10 +355,13 @@ static int acpi_processor_get_info(struct acpi_de= vice *device) > > * because cpuid <-> apicid mapping is persistent now. > > */ > > if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) { > > - int ret =3D acpi_processor_hotadd_init(pr); > > + int ret =3D acpi_processor_hotadd_init(pr, device); > > > > if (ret) > > return ret; > > + } else { > > + if (!acpi_processor_set_per_cpu(pr, device)) > > + return -EINVAL; > > } =20 >=20 > This looks a bit odd. >=20 > I would make acpi_processor_set_per_cpu() return 0 on success and > -EINVAL on failure and the above would become >=20 > if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) > ret =3D acpi_processor_hotadd_init(pr, device); > else > ret =3D acpi_processor_set_per_cpu(pr, device); >=20 > if (ret) > return ret; >=20 > (and of course ret needs to be defined at the beginning of the function). >=20 > > > > /* > > @@ -365,8 +407,6 @@ static int acpi_processor_get_info(struct acpi_devi= ce *device) > > * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. > > * Such things have to be put in and set up by the processor driver's = .probe(). > > */ > > -static DEFINE_PER_CPU(void *, processor_device_array); > > - > > static int acpi_processor_add(struct acpi_device *device, > > const struct acpi_device_id *id) > > { > > @@ -395,28 +435,6 @@ static int acpi_processor_add(struct acpi_device *= device, > > if (result) /* Processor is not physically present or unavailab= le */ > > goto err_clear_driver_data; > > > > - BUG_ON(pr->id >=3D nr_cpu_ids); > > - > > - /* > > - * Buggy BIOS check. > > - * ACPI id of processors can be reported wrongly by the BIOS. > > - * Don't trust it blindly > > - */ > > - if (per_cpu(processor_device_array, pr->id) !=3D NULL && > > - per_cpu(processor_device_array, pr->id) !=3D device) { > > - dev_warn(&device->dev, > > - "BIOS reported wrong ACPI id %d for the process= or\n", > > - pr->id); > > - /* Give up, but do not abort the namespace scan. */ > > - goto err_clear_driver_data; > > - } > > - /* > > - * processor_device_array is not cleared on errors to allow bug= gy BIOS > > - * checks. > > - */ > > - per_cpu(processor_device_array, pr->id) =3D device; > > - per_cpu(processors, pr->id) =3D pr; > > - > > dev =3D get_cpu_device(pr->id); > > if (!dev) { > > result =3D -ENODEV; > > @@ -470,10 +488,6 @@ static void acpi_processor_remove(struct acpi_devi= ce *device) > > device_release_driver(pr->dev); > > acpi_unbind_one(pr->dev); > > > > - /* Clean up. */ > > - per_cpu(processor_device_array, pr->id) =3D NULL; > > - per_cpu(processors, pr->id) =3D NULL; > > - > > cpu_maps_update_begin(); > > cpus_write_lock(); > > > > @@ -481,6 +495,10 @@ static void acpi_processor_remove(struct acpi_devi= ce *device) > > arch_unregister_cpu(pr->id); > > acpi_unmap_cpu(pr->id); > > > > + /* Clean up. */ > > + per_cpu(processor_device_array, pr->id) =3D NULL; > > + per_cpu(processors, pr->id) =3D NULL; > > + > > cpus_write_unlock(); > > cpu_maps_update_done(); > > > > -- > > 2.39.2 > > =20