From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 30623155307; Mon, 22 Apr 2024 19:10:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713813024; cv=none; b=Q5h6EXy28+SN3oymXnNL5E0I1/ggVzTxiJedgXNIZYfV9NqTkelAGQNf3z/GDCELRa2ARXUvh4rCpLeGlGPv8XP7ItVRa+s5Lm41oFDLSwvvtb8FY7gceHdxhD5f/RsHPAt31KNFy9ThS5PPMnDJMvQ/qAukJCmZ0326IP5IGDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713813024; c=relaxed/simple; bh=xr5Uhja78DTlat29wuEJWkFNot6eT4eX2GLpPmEimFo=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=X4Dj5ty9HezRIfCj9bWZjPy+swz9SHTzmasKxZvJ010j9PfyWV+t8daYXVKALXkK3te16waO1U9HU3b3zOfuF4WnaSAPSX/k1Yyds/P4dzeKBZmu9d3jAunUJbCmT6yeOvZ3JV+cxfDrjZRR9MCTccJakARtMdl4dnbQpke7KqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=I3u8AYCA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="I3u8AYCA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3C4EC4AF0C; Mon, 22 Apr 2024 19:10:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713813023; bh=xr5Uhja78DTlat29wuEJWkFNot6eT4eX2GLpPmEimFo=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=I3u8AYCAMeEZCdeNFQjGY0Fzjk1kTkDnwULJptJPBdSIr8PJHA8E2VZ2xdg20aR0X IsgzWC2am9NEkW0AsGb2v0fJ52Y26jsfKqjG8nTt58VuAgohpQVa1hDiy1+lNONOmi 3AikdQXQtPi7TBEnpSqgSsfMbFhRWTmHMjzcJU3yrjFNQlN9hsXqpk87XT9cNXZlDG O+aFL85Q7RgnBvbjYH0bqEj+3Rc7vW311VgW3rLDkexz7D2STu72DiqAvb6Dv8YIsJ mll/lKgroBVm/ONoG4dvYPD365rpZ98i+B/Z7g2AaNYb4qCZbnYvUZbq6mJpPUIbuY bANwacZE5Se9g== Received: by mail-ot1-f54.google.com with SMTP id 46e09a7af769-6eb50bbd8ceso781385a34.1; Mon, 22 Apr 2024 12:10:23 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCXUy1Wfvp5w8ps03QMlXNEX7rvkA42+IWVAv05YhEztJCu/o0Em3ZmUVQHT52rkk6Rm5qHEm5U0tfSKUGWBOWOylQNJ9ONHNWbDPjYm2arF2QumvdT7vAgP8/XqGO5eTmd9qnsFii3jnSWhSAdQfoAdiB/E7wzNn02a6npncm9Zb3w7l6vky87gyrZFzsWt5CXdvhG6n5VOvUG0a7lkRw== X-Gm-Message-State: AOJu0Yys1KUkMPIucCZ3wA/3SQYUKriXKg3lY2vVdC1GytqvIVpX76W0 lqWAXzn1G0KSR6vkz0D6NGLbUEBeUUz5EqvPpneRTjCB8X6fr17WtTG/6oPH7bNmQS6nMYb219d L1u4hJReqKtKIWw1sJjLWhWrE9qM= X-Google-Smtp-Source: AGHT+IGddIzuXRIOq0vcaD27xeni4nJNgz8BRaRjdkma7vizXw+C3Ho4ufbzOxRg6uAQwtupRrmwkhqM8niU4Ra55DE= X-Received: by 2002:a05:6871:2010:b0:233:abab:6d7e with SMTP id rx16-20020a056871201000b00233abab6d7emr13258560oab.1.1713813022998; Mon, 22 Apr 2024 12:10:22 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240418135412.14730-1-Jonathan.Cameron@huawei.com> <20240418135412.14730-9-Jonathan.Cameron@huawei.com> In-Reply-To: <20240418135412.14730-9-Jonathan.Cameron@huawei.com> From: "Rafael J. Wysocki" Date: Mon, 22 Apr 2024 21:10:12 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v7 08/16] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug To: Jonathan Cameron Cc: Thomas Gleixner , Peter Zijlstra , 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 , "Rafael J . Wysocki" , Miguel Luis , James Morse , Salil Mehta , Jean-Philippe Brucker , Catalin Marinas , Will Deacon , Ingo Molnar , Borislav Petkov , Dave Hansen , linuxarm@huawei.com, justin.he@arm.com, jianyong.wu@arm.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, Apr 18, 2024 at 3:58=E2=80=AFPM Jonathan Cameron wrote: > > From: James Morse > > struct acpi_scan_handler has a detach callback that is used to remove > a driver when a bus is changed. When interacting with an eject-request, > the detach callback is called before _EJ0. > > This means the ACPI processor driver can't use _STA to determine if a > CPU has been made not-present, or some of the other _STA bits have been > changed. acpi_processor_remove() needs to know the value of _STA after > _EJ0 has been called. > > Add a post_eject callback to struct acpi_scan_handler. This is called > after acpi_scan_hot_remove() has successfully called _EJ0. Because > acpi_scan_check_and_detach() also clears the handler pointer, > it needs to be told if the caller will go on to call > acpi_bus_post_eject(), so that acpi_device_clear_enumerated() > and clearing the handler pointer can be deferred. > An extra flag is added to flags field introduced in the previous > patch to achieve this. > > Signed-off-by: James Morse > Reviewed-by: Joanthan Cameron > Reviewed-by: Gavin Shan > Tested-by: Miguel Luis > Tested-by: Vishnu Pajjuri > Tested-by: Jianyong Wu > Signed-off-by: Jonathan Cameron No objections: Acked-by: Rafael J. Wysocki > ---- > v7: > - No change. > v6: > - Switch to flags. > Russell, you hadn't signed off on this when posting last time. > Do you want to insert a suitable tag now? > v5: > - Rebase to take into account the changes to scan handling in the > meantime. > --- > drivers/acpi/acpi_processor.c | 4 ++-- > drivers/acpi/scan.c | 30 +++++++++++++++++++++++++++--- > include/acpi/acpi_bus.h | 1 + > 3 files changed, 30 insertions(+), 5 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.= c > index 4e65011e706c..beb1761db579 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -471,7 +471,7 @@ static int acpi_processor_add(struct acpi_device *dev= ice, > > #ifdef CONFIG_ACPI_HOTPLUG_CPU > /* Removal */ > -static void acpi_processor_remove(struct acpi_device *device) > +static void acpi_processor_post_eject(struct acpi_device *device) > { > struct acpi_processor *pr; > > @@ -639,7 +639,7 @@ static struct acpi_scan_handler processor_handler =3D= { > .ids =3D processor_device_ids, > .attach =3D acpi_processor_add, > #ifdef CONFIG_ACPI_HOTPLUG_CPU > - .detach =3D acpi_processor_remove, > + .post_eject =3D acpi_processor_post_eject, > #endif > .hotplug =3D { > .enabled =3D true, > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index 1ec9677e6c2d..3ec54624664a 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -245,6 +245,7 @@ static int acpi_scan_try_to_offline(struct acpi_devic= e *device) > } > > #define ACPI_SCAN_CHECK_FLAG_STATUS BIT(0) > +#define ACPI_SCAN_CHECK_FLAG_EJECT BIT(1) > > static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p) > { > @@ -273,8 +274,6 @@ static int acpi_scan_check_and_detach(struct acpi_dev= ice *adev, void *p) > if (handler) { > if (handler->detach) > handler->detach(adev); > - > - adev->handler =3D NULL; > } else { > device_release_driver(&adev->dev); > } > @@ -284,6 +283,28 @@ static int acpi_scan_check_and_detach(struct acpi_de= vice *adev, void *p) > */ > acpi_device_set_power(adev, ACPI_STATE_D3_COLD); > adev->flags.initialized =3D false; > + > + /* For eject this is deferred to acpi_bus_post_eject() */ > + if (!(flags & ACPI_SCAN_CHECK_FLAG_EJECT)) { > + adev->handler =3D NULL; > + acpi_device_clear_enumerated(adev); > + } > + return 0; > +} > + > +static int acpi_bus_post_eject(struct acpi_device *adev, void *not_used) > +{ > + struct acpi_scan_handler *handler =3D adev->handler; > + > + acpi_dev_for_each_child_reverse(adev, acpi_bus_post_eject, NULL); > + > + if (handler) { > + if (handler->post_eject) > + handler->post_eject(adev); > + > + adev->handler =3D NULL; > + } > + > acpi_device_clear_enumerated(adev); > > return 0; > @@ -301,6 +322,7 @@ static int acpi_scan_hot_remove(struct acpi_device *d= evice) > acpi_handle handle =3D device->handle; > unsigned long long sta; > acpi_status status; > + uintptr_t flags =3D ACPI_SCAN_CHECK_FLAG_EJECT; > > if (device->handler && device->handler->hotplug.demand_offline) { > if (!acpi_scan_is_offline(device, true)) > @@ -313,7 +335,7 @@ static int acpi_scan_hot_remove(struct acpi_device *d= evice) > > acpi_handle_debug(handle, "Ejecting\n"); > > - acpi_bus_trim(device); > + acpi_scan_check_and_detach(device, (void *)flags); > > acpi_evaluate_lck(handle, 0); > /* > @@ -336,6 +358,8 @@ static int acpi_scan_hot_remove(struct acpi_device *d= evice) > } else if (sta & ACPI_STA_DEVICE_ENABLED) { > acpi_handle_warn(handle, > "Eject incomplete - status 0x%llx\n", sta); > + } else { > + acpi_bus_post_eject(device, NULL); > } > > return 0; > diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h > index e7796f373d0d..51a4b936f19e 100644 > --- a/include/acpi/acpi_bus.h > +++ b/include/acpi/acpi_bus.h > @@ -129,6 +129,7 @@ struct acpi_scan_handler { > bool (*match)(const char *idstr, const struct acpi_device_id **ma= tchid); > int (*attach)(struct acpi_device *dev, const struct acpi_device_i= d *id); > void (*detach)(struct acpi_device *dev); > + void (*post_eject)(struct acpi_device *dev); > void (*bind)(struct device *phys_dev); > void (*unbind)(struct device *phys_dev); > struct acpi_hotplug_profile hotplug; > -- > 2.39.2 >