From patchwork Wed Jan 31 16:50:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King (Oracle)" X-Patchwork-Id: 13539730 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 3FBFE12C520; Wed, 31 Jan 2024 16:50:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706719821; cv=none; b=t51TgYl5BMVhzHiGYVYxBkCGwiPvK0WmStWGb/1wN+6T1CgOTBV6UYpL5JguNUGkodwXBtyRyVtYb9M77zwNchOn2MvnevTgSVgW9cGeTxEKiB5BQXiA2u3wscxBJhm1qEUw8SZz3d3bedIwPzxNa/SOKkIidVSSbACeWIlLMrc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706719821; c=relaxed/simple; bh=zsywRTOSWlL1y/gNVXc+sID4lPGc1Plvmm3KF42XvQA=; h=In-Reply-To:References:From:To:Cc:Subject:MIME-Version: Content-Disposition:Content-Type:Message-Id:Date; b=IuzKpltJQHOJM3EHC4Zbqgmd5WVB+Jrxtp7OEjjRewiH6ryP2123kh0iezk9WsVg9tIOdxW3QMrFAcVGQSg0DyYE2yuXLgQ6AF0elicACfbPgCtDuh/sK06o1Nl8ZJs5hWTCOGVx6SVBlanvEKA+r7LW4xsWIYIVdo8UVtDoU84= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=KN6FCo1c; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="KN6FCo1c" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Date:Sender:Message-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Subject:Cc:To:From:References: In-Reply-To:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=9LqVoy1EEapHgmzXMm+nd2Z2DYgxk+ILn9F40nECUNw=; b=KN6FCo1cGJ1kXY/7+xL8MrAetb TUJaZcEBuuq5i6pd27a+eiP5VEe9fcafNt1v4KspHj2XHk2YPy5t2Ra7jgozD4DtNDEKHqkHcVK78 jGp64Jkt9Q9/uS8PUt4mfoy2xZnpVzKdGv4eD/WDGHSa7LwNwWk18reDwy7AadH/d33zZnHh28tno RRiWHkahGVPikchgY/uvM9KJTjkrw7Q3E2NelRhRRtVKrCyzyV0V1aV3a9Kly+No5qVU78Id/vcGX bocHn6meQ66fJoJIc9PgM//TyhJxK3TUCvA4JEEw5O4MDS5T88S+VHqez3pqVSj0AUR+zslOSEJBe /n3nLZxA==; Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:56560 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1rVDmn-0003UO-0m; Wed, 31 Jan 2024 16:50:05 +0000 Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1rVDmk-0027Yh-1E; Wed, 31 Jan 2024 16:50:02 +0000 In-Reply-To: References: From: Russell King (Oracle) 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, x86@kernel.org, acpica-devel@lists.linuxfoundation.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org Cc: Salil Mehta , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com, James Morse , Jonathan Cameron , "Rafael J. Wysocki" Subject: [PATCH RFC v4 05/15] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Message-Id: Sender: Russell King Date: Wed, 31 Jan 2024 16:50:02 +0000 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_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 Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu --- Outstanding comments: https://lore.kernel.org/r/20230914152809.00003152@Huawei.com https://lore.kernel.org/r/c3ef8123-1fcc-7289-c475-c753de44d564@redhat.com --- 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 fd8f3a0572cb..00809c3b09f7 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_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_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 2c8ba4526278..e4f4542f29af 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 e4d24d3f9abb..436e7e022e4e 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 **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;