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: 13383526 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 52281EE01E3 for ; Wed, 13 Sep 2023 16:41:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=O49z8CoUNXqYZDH/ZZCIfHSU3QkfilxmBFXqndJIO4k=; b=YLRCO2Ks2T543+ 2L7PsuAvkkkcLeOnfCp1eKS0e+dQ5NchjTBmUVbrD+J1IqCFy/kB0U9JEbb+g0ET6/AU69gBJfvMC VfaqSe0lEOC1/F5vQMePlv60LRelrsv6RYlGRK9+65dmgpv5pcw1jA8F5z5sZ4X4XLN3pRWM9h3TU mTYLcaGmiI4E4rNQUO9/tkOXHBJJmDJXNRpNjqgcCFsHUg5aZM9o0pzf+0qCDQwAwddDkwjpgT7sx t73wp8u0QGj9ztt3gs86lBCwuilXDEwE4Z9K0aEttA1qEE6+QN2EJQPPgPrUuNxEgDp8oz6GQWSWz uERv6vk2qyyLFrJhTjTQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgSvQ-006MzJ-0y; Wed, 13 Sep 2023 16:41:12 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgSts-006LRX-2b; Wed, 13 Sep 2023 16:39:39 +0000 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230913_093937_110313_95DFE626 X-CRM114-Status: GOOD ( 21.17 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.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;