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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34589C77B73 for ; Sun, 30 Apr 2023 21:02:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231225AbjD3VCR (ORCPT ); Sun, 30 Apr 2023 17:02:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229556AbjD3VCO (ORCPT ); Sun, 30 Apr 2023 17:02:14 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.17.21]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42C0B11B; Sun, 30 Apr 2023 14:02:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1682888503; i=w_armin@gmx.de; bh=PEGII6AuxuD7VYFwcTJIQfyjZIFa7pZZJovsYWSdjJ8=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=cPG90ClOWdrrUD8AegU1JSMS3L3nNl9vH/YxdxmHnqvpHmsJenNL6oJiFW5NH5CIf WoVu8DF+EX0vsfkI13mGcnfe2GojekqlIz8vVmcmBnLNTMDvUSQqfx0txP+CSHKQjB E5L5uIgJXMUybNeNofJdcAhJeYCiOQ3u6XoNdDY5eiSJBQz3Kab4WLvnmpTKBdgpi4 nnMqa2mo5ZBQ1bmL2gzl0CG5f1tlBXlWQkHKFGbMOZM+d/vXAoO4hXuKLeNxP4hehk BfMI1mKUlVoZOyGi0GVKQONHJtgUDGlnaCswsTGkAAOdQieasDT9mrovfGS904NR8o PgF9DAMijzXlQ== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [141.30.226.129] ([141.30.226.129]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MQvD5-1peYnh37Hr-00O1PH; Sun, 30 Apr 2023 23:01:42 +0200 Subject: Re: [PATCH 1/2] platform/x86: wmi: Allow retrieving the number of WMI object instances To: Hans de Goede , markgross@kernel.org Cc: Mario.Limonciello@amd.com, prasanth.ksr@dell.com, jorgealtxwork@gmail.com, james@equiv.tech, Dell.Client.Kernel@dell.com, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230430203153.5587-1-W_Armin@gmx.de> <20230430203153.5587-2-W_Armin@gmx.de> <756215f5-d99c-b172-13f6-1a15e026bf65@redhat.com> From: Armin Wolf Message-ID: <3bfa4a8c-1260-3fc0-9f83-2958467ca596@gmx.de> Date: Sun, 30 Apr 2023 23:01:41 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <756215f5-d99c-b172-13f6-1a15e026bf65@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Provags-ID: V03:K1:Oko3MpIp1yJChBT9DzLAUVTCYP5NEVrDj1u2I9ThGjP9YlrvHLI 8XVK75lzSKGfFVUIe5nbbXbaAAABIDAxINq9xLlIpj0RnPJqCAogoqsMDWGg1bVNee07txR MMf1p8SWvrNreeUbHsareVGHGhUduiH/MpaZRYSx6R0CZ9sWlqrx2A1vQulSfoWL9k/44dh /NEgVxTpTcmhmmSEWJHWg== UI-OutboundReport: notjunk:1;M01:P0:21QVCb4GZzU=;nTVL+aiMmmsjssZpXH0UtOA8Hw+ OJ31wP395vfTIxhLK/SxwpmvAVIBTEo572hTS/huXk/7usk7cMURgcWoMQ1zioRIV1gKMHV89 olz4K714YkkQkII4UTgPgcajNFlsXHuVCqR/+t4TOcxHgNFh+/w3M4CHdfvXUTyLRy8U+3BbD PCpdyh97gYjfyEzulXosg4rTMwGJ6OnDI2ESrGreGnmGXo9gxZPm5VdOC5nCAxQ9S+rG1BEK/ ej74uEVClGcPXVfeGRKgup1Xvfx3sikFS26ZbwkMQ6QzBEbjEtY8TxgNU/ROm4Ph35HVUQ/nF E6+ymM0I6dsfm7UwrECM/bSHZh57b7b9BH/vNy6CbE8l9XljwLtMy3QVGwsxMQeHKgRe0yVHB 7XMttz9fT6JsWglAHr/AsVHuTgd8PZ+Ks90ljrjOdWf4ndOF0ktautqEuWIkdevrl0qT7+s0P VsO++s/fVh8VKOj7mY2qClzd9a8ZITUe6n3APGGI4OIvUrS/p6a+eXIVPu4cJice9jti5eZ9Z FKVsgyQUzORjRE71pVRZ0xga2CjkgCkoqH8hG/q2H6h/JULxlrHIya4CMNRvktF/FPKvfm0j4 L81WvqobA7cFfmaemxktTsS8Egr9ZrVZDFEgs1Ln/37O5Fo44xTXeXb5ltq5s33hoc9GMoVS7 HmFfarhpLoAVdJ874nV6XjMvCacSWBE/KZimQrpX0MduonDH7S0GRC1Mo4fZH9OcMAuiGskPK tAIAkqC+atj4z79RX8UnYO7HlnPSVDeRGmzPHNV4T5waq8CoAYYhLoLq9UwrVz0BMwvCasnoC f9/d468DLO8a9Z2zaLL03EtanvY47c3KS2Q4OxXWXezZPIEpaT6EnjDCbS0sOnKzNThRsTf0D HPsaOs0PRVIt20y4DkQ5czNZPQSBrM6l4fN/SM8FPdB4ABYxA945hRNiA5gpuXTqcEclEjxAU xJ7GIaoSysk+yH1HZMBWHlPKt2o= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 30.04.23 um 22:41 schrieb Hans de Goede: > Hi Armin, > > On 4/30/23 22:31, Armin Wolf wrote: >> Currently, the WMI driver core knows how many instances of a given >> WMI object exist, but WMI drivers cannot access this information. >> At the same time, some current and upcoming WMI drivers want to >> have access to this information. Add wmi_instance_count() and >> wmidev_instance_count() to allow WMI drivers to get the number of >> WMI object instances. >> >> Signed-off-by: Armin Wolf > Thank you for your work on this. > >> --- >> drivers/platform/x86/wmi.c | 41 ++++++++++++++++++++++++++++++++++++++ >> include/linux/acpi.h | 2 ++ >> include/linux/wmi.h | 2 ++ >> 3 files changed, 45 insertions(+) >> >> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c >> index c226dd4163a1..5b95d7aa5c2f 100644 >> --- a/drivers/platform/x86/wmi.c >> +++ b/drivers/platform/x86/wmi.c >> @@ -263,6 +263,47 @@ int set_required_buffer_size(struct wmi_device *wdev, u64 length) >> } >> EXPORT_SYMBOL_GPL(set_required_buffer_size); >> >> +/** >> + * wmi_instance_count - Get number of WMI object instances >> + * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba >> + * >> + * Get the number of WMI object instances. >> + * >> + * Returns: Number of WMI object instances or negative error code. >> + */ >> +int wmi_instance_count(const char *guid_string) >> +{ >> + struct wmi_block *wblock; >> + acpi_status status; >> + >> + status = find_guid(guid_string, &wblock); >> + if (ACPI_FAILURE(status)) { >> + if (status == AE_BAD_PARAMETER) >> + return -EINVAL; >> + >> + return -ENODEV; > Maybe just return 0 here ? > > The GUID not existing at all does not seem like > an error to me, but rather a case of there > being 0 instances. > > This will also allow patch 2/2 to completely > drop the get_instance_count() function and > replace its callers with direct calls to > wmi_instance_count() as the code is known > to always pass a valid GUID, so it won't hit > the -EINVAL path. > > Regards, > > Hans > Hi, i would prefer returning -ENODEV instead of 0, so WMI drivers can distinguish between "not found" and "zero instances". Also i do not think that relying on the parameter of get_instance_count() always being a valid GUID is a good idea, just in case wmi_instance_count() is later modified to be able to encounter runtime errors. Armin Wolf > >> + } >> + >> + return wmidev_instance_count(&wblock->dev); >> +} >> +EXPORT_SYMBOL_GPL(wmi_instance_count); >> + >> +/** >> + * wmidev_instance_count - Get number of WMI object instances >> + * @wdev: A wmi bus device from a driver >> + * >> + * Get the number of WMI object instances. >> + * >> + * Returns: Number of WMI object instances. >> + */ >> +u8 wmidev_instance_count(struct wmi_device *wdev) >> +{ >> + struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev); >> + >> + return wblock->gblock.instance_count; >> +} >> +EXPORT_SYMBOL_GPL(wmidev_instance_count); >> + >> /** >> * wmi_evaluate_method - Evaluate a WMI method (deprecated) >> * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba >> diff --git a/include/linux/acpi.h b/include/linux/acpi.h >> index efff750f326d..e52bf2742eaf 100644 >> --- a/include/linux/acpi.h >> +++ b/include/linux/acpi.h >> @@ -412,6 +412,8 @@ extern bool acpi_is_pnp_device(struct acpi_device *); >> >> typedef void (*wmi_notify_handler) (u32 value, void *context); >> >> +int wmi_instance_count(const char *guid); >> + >> extern acpi_status wmi_evaluate_method(const char *guid, u8 instance, >> u32 method_id, >> const struct acpi_buffer *in, >> diff --git a/include/linux/wmi.h b/include/linux/wmi.h >> index c1a3bd4e4838..763bd382cf2d 100644 >> --- a/include/linux/wmi.h >> +++ b/include/linux/wmi.h >> @@ -35,6 +35,8 @@ extern acpi_status wmidev_evaluate_method(struct wmi_device *wdev, >> extern union acpi_object *wmidev_block_query(struct wmi_device *wdev, >> u8 instance); >> >> +u8 wmidev_instance_count(struct wmi_device *wdev); >> + >> extern int set_required_buffer_size(struct wmi_device *wdev, u64 length); >> >> /** >> -- >> 2.30.2 >>