From mboxrd@z Thu Jan 1 00:00:00 1970 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 03ED0CA553C for ; Thu, 14 Sep 2023 13:10:21 +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:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=SjIKpCpEO786NIDUaaKVGB83K6kOMs2K3i4dATMYArw=; b=zPnPHy0OVaPlD+ JHn/jgKT5oFAgFTejCO4dLBphw2UIerBgVPptN9WXfyZLMEl6aYA9A6k3Tk4GvJoOtax83cSufhWU b1Zscwqq5KFBplzNot4AUUtNNVFfB2w5p45LHTl+h4i4uH6qRxYlwU564DMLkuHv1OHUPOXntKVVQ MuasNx5DvHRKcc7AEw11sVrmOKSSfjJ+EVbAGyYVng07URBlz1m/0Z1oFPmVDhQT91HfBBUVVm/A6 KnqY0UzXqaAsN+xsXMsq4ppetlI5GRRDG5VawTL3FH/g8NkP1l/gcyyP3CHL/UHRVeXoEPBA8tOPB lOKUbE9hRoIOeVIa8J2Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgm6V-008Pe5-0g; Thu, 14 Sep 2023 13:09:55 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qgm6S-008Pcw-0n; Thu, 14 Sep 2023 13:09:54 +0000 Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Rmd0X0KkPz6HJdv; Thu, 14 Sep 2023 21:07:56 +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_128_GCM_SHA256) id 15.1.2507.31; Thu, 14 Sep 2023 14:09:41 +0100 Date: Thu, 14 Sep 2023 14:09:40 +0100 From: Jonathan Cameron To: James Morse CC: , , , , , , , , , Salil Mehta , Russell King , Jean-Philippe Brucker , , Subject: Re: [RFC PATCH v2 14/35] ACPI: Only enumerate enabled (or functional) devices Message-ID: <20230914140940.00001417@Huawei.com> In-Reply-To: <20230914132732.00006908@Huawei.com> References: <20230913163823.7880-1-james.morse@arm.com> <20230913163823.7880-15-james.morse@arm.com> <20230914132732.00006908@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) MIME-Version: 1.0 X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100006.china.huawei.com (7.191.160.224) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230914_060952_588911_8F42E8A1 X-CRM114-Status: GOOD ( 38.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 14 Sep 2023 13:27:32 +0100 Jonathan Cameron wrote: > On Wed, 13 Sep 2023 16:38:02 +0000 > James Morse wrote: > > > Today the ACPI enumeration code 'visits' all devices that are present. > > > > This is a problem for arm64, where CPUs are always present, but not > > always enabled. When a device-check occurs because the firmware-policy > > has changed and a CPU is now enabled, the following error occurs: > > | acpi ACPI0007:48: Enumeration failure > > > > This is ultimately because acpi_dev_ready_for_enumeration() returns > > true for a device that is not enabled. The ACPI Processor driver > > will not register such CPUs as they are not 'decoding their resources'. > > > > Change acpi_dev_ready_for_enumeration() to also check the enabled bit. > > ACPI allows a device to be functional instead of maintaining the > > present and enabled bit. Make this behaviour an explicit check with > > a reference to the spec, and then check the present and enabled bits. > > "and the" only applies if the functional route hasn't been followed > "if not this case check the present and enabled bits." > > > This is needed to avoid enumerating present && functional devices that > > are not enabled. > > > > Signed-off-by: James Morse > > --- > > If this change causes problems on deployed hardware, I suggest an > > arch opt-in: ACPI_IGNORE_STA_ENABLED, that causes > > acpi_dev_ready_for_enumeration() to only check the present bit. > > --- > > drivers/acpi/device_pm.c | 2 +- > > drivers/acpi/device_sysfs.c | 2 +- > > drivers/acpi/internal.h | 1 - > > drivers/acpi/property.c | 2 +- > > drivers/acpi/scan.c | 23 +++++++++++++---------- > > 5 files changed, 16 insertions(+), 14 deletions(-) > > > > diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c > > index f007116a8427..76c38478a502 100644 > > --- a/drivers/acpi/device_pm.c > > +++ b/drivers/acpi/device_pm.c > > @@ -313,7 +313,7 @@ int acpi_bus_init_power(struct acpi_device *device) > > return -EINVAL; > > > > device->power.state = ACPI_STATE_UNKNOWN; > > - if (!acpi_device_is_present(device)) { > > + if (!acpi_dev_ready_for_enumeration(device)) { > > device->flags.initialized = false; > > return -ENXIO; > > } > > diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c > > index b9bbf0746199..16e586d74aa2 100644 > > --- a/drivers/acpi/device_sysfs.c > > +++ b/drivers/acpi/device_sysfs.c > > @@ -141,7 +141,7 @@ static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalia > > struct acpi_hardware_id *id; > > > > /* Avoid unnecessarily loading modules for non present devices. */ > > - if (!acpi_device_is_present(acpi_dev)) > > + if (!acpi_dev_ready_for_enumeration(acpi_dev)) > > return 0; > > > > /* > > diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h > > index 866c7c4ed233..a1b45e345bcc 100644 > > --- a/drivers/acpi/internal.h > > +++ b/drivers/acpi/internal.h > > @@ -107,7 +107,6 @@ int acpi_device_setup_files(struct acpi_device *dev); > > void acpi_device_remove_files(struct acpi_device *dev); > > void acpi_device_add_finalize(struct acpi_device *device); > > void acpi_free_pnp_ids(struct acpi_device_pnp *pnp); > > -bool acpi_device_is_present(const struct acpi_device *adev); > > bool acpi_device_is_battery(struct acpi_device *adev); > > bool acpi_device_is_first_physical_node(struct acpi_device *adev, > > const struct device *dev); > > diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c > > index 413e4fcadcaf..e03f00b98701 100644 > > --- a/drivers/acpi/property.c > > +++ b/drivers/acpi/property.c > > @@ -1418,7 +1418,7 @@ static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode) > > if (!is_acpi_device_node(fwnode)) > > return false; > > > > - return acpi_device_is_present(to_acpi_device_node(fwnode)); > > + return acpi_dev_ready_for_enumeration(to_acpi_device_node(fwnode)); > > } > > > > static const void * > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > > index 17ab875a7d4e..f898591ce05f 100644 > > --- a/drivers/acpi/scan.c > > +++ b/drivers/acpi/scan.c > > @@ -304,7 +304,7 @@ static int acpi_scan_device_check(struct acpi_device *adev) > > int error; > > > > acpi_bus_get_status(adev); > > - if (acpi_device_is_present(adev)) { > > + if (acpi_dev_ready_for_enumeration(adev)) { > > /* > > * This function is only called for device objects for which > > * matching scan handlers exist. The only situation in which > > @@ -338,7 +338,7 @@ static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used) > > int error; > > > > acpi_bus_get_status(adev); > > - if (!acpi_device_is_present(adev)) { > > + if (!acpi_dev_ready_for_enumeration(adev)) { > > acpi_scan_device_not_enumerated(adev); > > return 0; > > } > > @@ -1908,11 +1908,6 @@ static bool acpi_device_should_be_hidden(acpi_handle handle) > > return true; > > } > > > > -bool acpi_device_is_present(const struct acpi_device *adev) > > -{ > > - return adev->status.present || adev->status.functional; > > -} > > - > > static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler, > > const char *idstr, > > const struct acpi_device_id **matchid) > > @@ -2375,16 +2370,24 @@ EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies); > > * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration > > * @device: Pointer to the &struct acpi_device to check > > * > > - * Check if the device is present and has no unmet dependencies. > > + * Check if the device is functional or enabled and has no unmet dependencies. > > * > > - * Return true if the device is ready for enumeratino. Otherwise, return false. > > + * Return true if the device is ready for enumeration. Otherwise, return false. > > */ > > bool acpi_dev_ready_for_enumeration(const struct acpi_device *device) > > { > > if (device->flags.honor_deps && device->dep_unmet) > > return false; > > > > - return acpi_device_is_present(device); > > + /* > > + * ACPI 6.5's 6.3.7 "_STA (Device Status)" allows firmware to return > > + * (!present && functional) for certain types of devices that should be > > + * enumerated. > > I'd call out the fact that enumeration isn't same as "device driver should be loaded" > which is the thing that functional is supposed to indicate should not happen. > > > + */ > > + if (!device->status.present && !device->status.enabled) > > In theory no need to check !enabled if !present > "If bit [0] is cleared, then bit 1 must also be cleared (in other words, a device that is not present cannot be enabled)." > We could report an ACPI bug if that's seen. If that bug case is ignored this code can > become the simpler. > > if (device->status.present) > return device->status_enabled; > else > return device->status.functional; > > Or the following also valid here (as functional should be set for enabled present devices > unless they failed diagnostics). > > if (dev->status.functional) > return true; > return device->status.present && device->status.enabled; > > On assumption we want to enumerate dead devices for debug purposes... Actually ignore this. Could have weird race with present, functional true, but enabled not quite set - despite the device being there and self tests having passed. > > > > + return device->status.functional; > > + > > + return device->status.present && device->status.enabled; > > > > } > > EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration); > > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel