From patchwork Wed May 24 11:41:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 685384 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 5CE30C77B7A for ; Wed, 24 May 2023 11:48:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230273AbjEXLss (ORCPT ); Wed, 24 May 2023 07:48:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229614AbjEXLsp (ORCPT ); Wed, 24 May 2023 07:48:45 -0400 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9E6A12E; Wed, 24 May 2023 04:48:34 -0700 (PDT) Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 5.2.0) id 3b00b2c833d42bdd; Wed, 24 May 2023 13:48:33 +0200 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by v370.home.net.pl (Postfix) with ESMTPSA id C020069D7E2; Wed, 24 May 2023 13:48:32 +0200 (CEST) From: "Rafael J. Wysocki" To: Linux ACPI , Sakari Ailus Cc: LKML , Hans de Goede , Andy Shevchenko Subject: [PATCH v1 1/6] ACPI: property: Support using strings in reference properties Date: Wed, 24 May 2023 13:41:06 +0200 Message-ID: <8228386.T7Z3S40VBb@kreacher> In-Reply-To: <13276375.uLZWGnKmhe@kreacher> References: <13276375.uLZWGnKmhe@kreacher> MIME-Version: 1.0 X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvhedrfeejhedggeefucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecujffqoffgrffnpdggtffipffknecuuegrihhlohhuthemucduhedtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufffkfgjfhgggfgtsehtufertddttdejnecuhfhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqnecuggftrfgrthhtvghrnhepvdffueeitdfgvddtudegueejtdffteetgeefkeffvdeftddttdeuhfegfedvjefhnecukfhppeduleehrddufeeirdduledrleegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepudelhedrudefiedrudelrdelgedphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqedpnhgspghrtghpthhtohephedprhgtphhtthhopehlihhnuhigqdgrtghpihesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehsrghkrghrihdrrghilhhusheslhhinhhugidrihhnthgvlhdrtghomhdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehhuggvghhovgguvgesrhgvughhrghtrdgtohhmpdhrtghpthht oheprghnughrihihrdhshhgvvhgthhgvnhhkoheslhhinhhugidrihhnthgvlhdrtghomh X-DCC--Metrics: v370.home.net.pl 1024; Body=5 Fuz1=5 Fuz2=5 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org From: Rafael J. Wysocki In order to allow referencing data nodes directly, which is not possible currently, add support for representing references in device properties as strings (relative or absolute name paths). For example, after this change, the "mipi-img-flash-leds" property in the ASL snippet below will be treated as a proper reference to the LED0 object under LEDD. Package () { "mipi-img-flash-leds", "\\_SB.PCI0.I2C2.LEDD.LED0", } Device (LEDD) { Name (_DSD, Package () // _DSD: Device-Specific Data { ToUUID ("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), /* Hierarchical Data Extension */, Package () { Package () { "mipi-img-flash-led-0", "LED0", } }, }) Name (LED0, Package () // _DSD: Device-Specific Data { ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301") /* Device Properties */, Package () { Package () { "mipi-img-max-current", 1000000, } } }) } Also remove the mechanism allowing data nodes to be referenced indirectly, with the help of an object reference pointing to the "ancestor" device and a path relative to it (this mechanism is not expected to be in use in any production platform firmware in the field). Note that this change allows also using strings for referencing device objects, in addition to object references that have been supported already. While at it, add pr_fmt() macro to prefix printouts and update copyright. Co-developed-by: Sakari Ailus Signed-off-by: Sakari Ailus Signed-off-by: Rafael J. Wysocki --- drivers/acpi/property.c | 102 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 82 insertions(+), 20 deletions(-) Index: linux-pm/drivers/acpi/property.c =================================================================== --- linux-pm.orig/drivers/acpi/property.c +++ linux-pm/drivers/acpi/property.c @@ -2,14 +2,17 @@ /* * ACPI device specific properties support. * - * Copyright (C) 2014, Intel Corporation + * Copyright (C) 2014 - 2023, Intel Corporation * All rights reserved. * * Authors: Mika Westerberg * Darren Hart * Rafael J. Wysocki + * Sakari Ailus */ +#define pr_fmt(fmt) "ACPI: " fmt + #include #include #include @@ -800,27 +803,15 @@ static int acpi_get_ref_args(struct fwno u32 nargs = 0, i; /* - * Find the referred data extension node under the - * referred device node. - */ - for (; *element < end && (*element)->type == ACPI_TYPE_STRING; - (*element)++) { - const char *child_name = (*element)->string.pointer; - - ref_fwnode = acpi_fwnode_get_named_child_node(ref_fwnode, child_name); - if (!ref_fwnode) - return -EINVAL; - } - - /* * Assume the following integer elements are all args. Stop counting on - * the first reference or end of the package arguments. In case of - * neither reference, nor integer, return an error, we can't parse it. + * the first reference (possibly represented as a string) or end of the + * package arguments. In case of neither reference, nor integer, return + * an error, we can't parse it. */ for (i = 0; (*element) + i < end && i < num_args; i++) { acpi_object_type type = (*element)[i].type; - if (type == ACPI_TYPE_LOCAL_REFERENCE) + if (type == ACPI_TYPE_LOCAL_REFERENCE || type == ACPI_TYPE_STRING) break; if (type == ACPI_TYPE_INTEGER) @@ -844,6 +835,44 @@ static int acpi_get_ref_args(struct fwno return 0; } +static struct fwnode_handle *acpi_parse_string_ref(const struct fwnode_handle *fwnode, + const char *refstring) +{ + acpi_handle scope, handle; + struct acpi_data_node *dn; + struct acpi_device *device; + acpi_status status; + + if (is_acpi_device_node(fwnode)) { + scope = to_acpi_device_node(fwnode)->handle; + } else if (is_acpi_data_node(fwnode)) { + scope = to_acpi_data_node(fwnode)->handle; + } else { + pr_debug("Bad node type for node %pfw\n", fwnode); + return NULL; + } + + status = acpi_get_handle(scope, refstring, &handle); + if (ACPI_FAILURE(status)) { + acpi_handle_debug(scope, "Unable to get an ACPI handle for %s\n", + refstring); + return NULL; + } + + device = acpi_fetch_acpi_dev(handle); + if (device) + return acpi_fwnode_handle(device); + + status = acpi_get_data_full(handle, acpi_nondev_subnode_tag, + (void **)&dn, NULL); + if (ACPI_FAILURE(status) || !dn) { + acpi_handle_debug(handle, "Subnode not found\n"); + return NULL; + } + + return &dn->fwnode; +} + /** * __acpi_node_get_property_reference - returns handle to the referenced object * @fwnode: Firmware node to get the property from @@ -886,6 +915,7 @@ int __acpi_node_get_property_reference(c const union acpi_object *element, *end; const union acpi_object *obj; const struct acpi_device_data *data; + struct fwnode_handle *ref_fwnode; struct acpi_device *device; int ret, idx = 0; @@ -909,16 +939,30 @@ int __acpi_node_get_property_reference(c args->fwnode = acpi_fwnode_handle(device); args->nargs = 0; + + return 0; + case ACPI_TYPE_STRING: + if (index) + return -ENOENT; + + ref_fwnode = acpi_parse_string_ref(fwnode, obj->string.pointer); + if (!ref_fwnode) + return -EINVAL; + + args->fwnode = ref_fwnode; + args->nargs = 0; + return 0; case ACPI_TYPE_PACKAGE: /* * If it is not a single reference, then it is a package of - * references followed by number of ints as follows: + * references, followed by number of ints as follows: * * Package () { REF, INT, REF, INT, INT } * - * The index argument is then used to determine which reference - * the caller wants (along with the arguments). + * Here, REF may be either a local reference or a string. The + * index argument is then used to determine which reference the + * caller wants (along with the arguments). */ break; default: @@ -946,6 +990,24 @@ int __acpi_node_get_property_reference(c if (ret < 0) return ret; + if (idx == index) + return 0; + + break; + case ACPI_TYPE_STRING: + ref_fwnode = acpi_parse_string_ref(fwnode, + element->string.pointer); + if (!ref_fwnode) + return -EINVAL; + + element++; + + ret = acpi_get_ref_args(idx == index ? args : NULL, + ref_fwnode, &element, end, + num_args); + if (ret < 0) + return ret; + if (idx == index) return 0;