From patchwork Wed Sep 13 16:38:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 722145 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBB5FEE01E3 for ; Wed, 13 Sep 2023 16:41:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231256AbjIMQlD (ORCPT ); Wed, 13 Sep 2023 12:41:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231266AbjIMQj5 (ORCPT ); Wed, 13 Sep 2023 12:39:57 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 827F61BE1; Wed, 13 Sep 2023 09:39:35 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 758D8C15; Wed, 13 Sep 2023 09:40:12 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6006F3F5A1; Wed, 13 Sep 2023 09:39:33 -0700 (PDT) From: James Morse 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 Cc: x86@kernel.org, Salil Mehta , Russell King , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com Subject: [RFC PATCH v2 21/35] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug Date: Wed, 13 Sep 2023 16:38:09 +0000 Message-Id: <20230913163823.7880-22-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230913163823.7880-1-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org 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_bus_trim_one() 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. The existing not-used pointer is used for this. Signed-off-by: James Morse Reviewed-by: Joanthan Cameron Reviewed-by: Gavin Shan --- drivers/acpi/acpi_processor.c | 4 +-- drivers/acpi/scan.c | 52 ++++++++++++++++++++++++++++++----- include/acpi/acpi_bus.h | 1 + 3 files changed, 48 insertions(+), 9 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 22a15a614f95..00dcc23d49a8 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -459,7 +459,7 @@ static int acpi_processor_add(struct acpi_device *device, #ifdef CONFIG_ACPI_HOTPLUG_PRESENT_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; @@ -627,7 +627,7 @@ static struct acpi_scan_handler processor_handler = { .ids = processor_device_ids, .attach = acpi_processor_add, #ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU - .detach = acpi_processor_remove, + .post_eject = acpi_processor_post_eject, #endif .hotplug = { .enabled = true, diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index a675333618ae..b6d2f01640a9 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -244,18 +244,28 @@ static int acpi_scan_try_to_offline(struct acpi_device *device) return 0; } -static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) +/** + * acpi_bus_trim_one() - Detach scan handlers and drivers from ACPI device + * objects. + * @adev: Root of the ACPI namespace scope to walk. + * @eject: Pointer to a bool that indicates if this was due to an + * eject-request. + * + * Must be called under acpi_scan_lock. + * If @eject points to true, clearing the device enumeration is deferred until + * acpi_bus_post_eject() is called. + */ +static int acpi_bus_trim_one(struct acpi_device *adev, void *eject) { struct acpi_scan_handler *handler = adev->handler; + bool is_eject = *(bool *)eject; - acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL); + acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, eject); adev->flags.match_driver = false; if (handler) { if (handler->detach) handler->detach(adev); - - adev->handler = NULL; } else { device_release_driver(&adev->dev); } @@ -265,7 +275,12 @@ static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) */ acpi_device_set_power(adev, ACPI_STATE_D3_COLD); adev->flags.initialized = false; - acpi_device_clear_enumerated(adev); + + /* For eject this is deferred to acpi_bus_post_eject() */ + if (!is_eject) { + adev->handler = NULL; + acpi_device_clear_enumerated(adev); + } return 0; } @@ -278,15 +293,36 @@ static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) */ void acpi_bus_trim(struct acpi_device *adev) { - acpi_bus_trim_one(adev, NULL); + bool eject = false; + + acpi_bus_trim_one(adev, &eject); } EXPORT_SYMBOL_GPL(acpi_bus_trim); +static int acpi_bus_post_eject(struct acpi_device *adev, void *not_used) +{ + struct acpi_scan_handler *handler = 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 = NULL; + } + + acpi_device_clear_enumerated(adev); + + return 0; +} + static int acpi_scan_hot_remove(struct acpi_device *device) { acpi_handle handle = device->handle; unsigned long long sta; acpi_status status; + bool eject = true; if (device->handler && device->handler->hotplug.demand_offline) { if (!acpi_scan_is_offline(device, true)) @@ -299,7 +335,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device) acpi_handle_debug(handle, "Ejecting\n"); - acpi_bus_trim(device); + acpi_bus_trim_one(device, &eject); acpi_evaluate_lck(handle, 0); /* @@ -322,6 +358,8 @@ static int acpi_scan_hot_remove(struct acpi_device *device) } 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 254685085c82..1b7e1acf925b 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -127,6 +127,7 @@ struct acpi_scan_handler { bool (*match)(const char *idstr, const struct acpi_device_id **matchid); int (*attach)(struct acpi_device *dev, const struct acpi_device_id *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;