From patchwork Wed Sep 29 00:43:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Saheed O. Bolarinwa" X-Patchwork-Id: 12524237 X-Patchwork-Delegate: bhelgaas@google.com 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8EFC6C433EF for ; Wed, 29 Sep 2021 00:43:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 716EF60FD7 for ; Wed, 29 Sep 2021 00:43:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243429AbhI2ApL (ORCPT ); Tue, 28 Sep 2021 20:45:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243445AbhI2ApK (ORCPT ); Tue, 28 Sep 2021 20:45:10 -0400 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E650C06161C; Tue, 28 Sep 2021 17:43:30 -0700 (PDT) Received: by mail-ed1-x52d.google.com with SMTP id b26so2134354edt.0; Tue, 28 Sep 2021 17:43:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=DSFOLGj+ldMLpWwvrw+YF05JUnP09SptyU46Tu5pKP8=; b=MfgLaif9MxDFglnFowBdbImagCB3aKbME40C2VMsZFfRaqtkg8zx2a3ZGNP226ftdB NG5O94glOA6iIkWd8srW3nuwD7q4Q12VRASf94jT9kfjtmcW0APWrGgrKiUwcubnYgRz TgOi+6w45j2yx53yqWXNwAOXoistDSjfVD8uQsW0FhBBEp52zfEM/y/kkZFQ4VrvJSDN zqaGvA9LQfu1KcDatEqBQMa1kxMWWy/CJ79BqOcyWXwPnUmYR9lWeTM/NEOMDjuf4r1p 3DrGPPdyFzUi+yccCAghI5BnR/0PeqO17RnrjFXXJFIjvW1cM3MQhIUad3yBijStIExX tXgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=DSFOLGj+ldMLpWwvrw+YF05JUnP09SptyU46Tu5pKP8=; b=rHTZvLdwCmkcpB9209DV3qaxxDkSkIMU30YsjOPdGDSzwuOSQw8xLnsNDPTekHiwL0 cmExVfs+wVn75GFgyyyInY5mrXFtuI0gbJBLFp52q2kB42nQTd45pQE8kHXIz1xL63gq IojhtVeKyUuHc+beaWKr1mL7vlV1+L0S1Q0SurFUcKVvq4H6g0adfwxEPin0v93cflq6 icEI2I22D/Q6JJ7BEBFjfMWEDB9QJR5aj4dbar3Db8iJ0Y8nF6RmAQjnNzLTnTsXnqbt eacNOI33Bm9a/1BLW9+OLiIV6dvKzcjKLuhohJAJuUSW9+GYrMsCd+AXgXXT/tJaIRf9 6TsQ== X-Gm-Message-State: AOAM5308nQ/2R0L8DfKpEU+drHNrjqWia36fBDSm+dB+3Hy/PCKC0p+/ 7TTq6tiOs+QAk5XQADbp+WUpt+ef6rs= X-Google-Smtp-Source: ABdhPJxorhRNcrxYpwWl+HWgSIvah92yltiH8ybFhvmNOkaRT0MzFhc05p8M/dDnwnjVbfnUvOb+MQ== X-Received: by 2002:a05:6402:1b8d:: with SMTP id cc13mr11359421edb.235.1632876208678; Tue, 28 Sep 2021 17:43:28 -0700 (PDT) Received: from localhost.localdomain ([2a02:ab88:10f:c9f0:35c7:3af0:a197:61d0]) by smtp.googlemail.com with ESMTPSA id u16sm358489ejy.14.2021.09.28.17.43.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Sep 2021 17:43:28 -0700 (PDT) From: "Saheed O. Bolarinwa" To: helgaas@kernel.org Cc: "Bolarinwa O. Saheed" , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v2 2/4] PCI/ASPM: Remove struct pcie_link_state.root Date: Wed, 29 Sep 2021 02:43:13 +0200 Message-Id: <20210929004315.22558-3-refactormyself@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210929004315.22558-1-refactormyself@gmail.com> References: <20210929004315.22558-1-refactormyself@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: "Bolarinwa O. Saheed" Information on the root device is cached in struct pcie_link_state.root it obtained within alloc_pcie_link_state(). This patch: - creates *pcie_get_root()* which return the root pci_dev of a pci_dev. - removes *root* from the *struct pcie_link_state*. - replaces references to struct pcie_link_state.root with a call to pcie_get_root(). Signed-off-by: Bolarinwa O. Saheed --- drivers/pci/pcie/aspm.c | 69 +++++++++++++++++++++-------------------- 1 file changed, 35 insertions(+), 34 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 414c04ffe962..ad78aaeea444 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -49,7 +49,6 @@ struct aspm_latency { struct pcie_link_state { struct pci_dev *pdev; /* Upstream component of the Link */ struct pci_dev *downstream; /* Downstream component, function 0 */ - struct pcie_link_state *root; /* pointer to the root port link */ struct list_head sibling; /* node in link_list */ /* ASPM state */ @@ -851,6 +850,25 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev) return 0; } +/* + * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe + * hierarchies. Note that some PCIe host implementations omit + * the root ports entirely, in which case a downstream port on + * a switch may become the root of the link state chain for all + * its subordinate endpoints. + */ +static struct pci_dev *pcie_get_root(struct pci_dev *pdev) +{ + struct pci_dev *parent = pci_get_parent(pdev); + + if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT || + pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE || !parent) { + return pdev; + } else { + return pcie_get_root(parent); + } +} + static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) { struct pcie_link_state *link; @@ -863,29 +881,6 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) link->pdev = pdev; link->downstream = pci_function_0(pdev->subordinate); - /* - * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe - * hierarchies. Note that some PCIe host implementations omit - * the root ports entirely, in which case a downstream port on - * a switch may become the root of the link state chain for all - * its subordinate endpoints. - */ - if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT || - pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE || - !pdev->bus->parent->self) { - link->root = link; - } else { - struct pci_dev *parent; - - parent = pci_get_parent(pdev); - if (!parent->link_state) { - kfree(link); - return NULL; - } - - link->root = parent->link_state->root; - } - list_add(&link->sibling, &link_list); pdev->link_state = link; return link; @@ -972,21 +967,26 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) static void pcie_update_aspm_capable(struct pcie_link_state *root) { struct pcie_link_state *link; - struct pci_dev *parent = pci_get_parent(root->pdev); + struct pci_dev *dev, *root_dev; - if (parent && parent->link_state) - root = parent->link_state->root; + /* Ensure it is the root device */ + root_dev = pcie_get_root(root->pdev); + root = root_dev ? root_dev->link_state : NULL; list_for_each_entry(link, &link_list, sibling) { - if (link->root != root) + dev = pcie_get_root(link->pdev); + if (dev->link_state != root) continue; + link->aspm_capable = link->aspm_support; } list_for_each_entry(link, &link_list, sibling) { struct pci_dev *child; struct pci_bus *linkbus = link->pdev->subordinate; - if (link->root != root) + dev = pcie_get_root(link->pdev); + if (dev->link_state != root) continue; + list_for_each_entry(child, &linkbus->devices, bus_list) { if ((pci_pcie_type(child) != PCI_EXP_TYPE_ENDPOINT) && (pci_pcie_type(child) != PCI_EXP_TYPE_LEG_END)) @@ -999,9 +999,9 @@ static void pcie_update_aspm_capable(struct pcie_link_state *root) /* @pdev: the endpoint device */ void pcie_aspm_exit_link_state(struct pci_dev *pdev) { - struct pci_dev *parent_dev; + struct pci_dev *parent_dev, *root_dev; struct pci_dev *parent = pdev->bus->self; - struct pcie_link_state *link, *root, *parent_link; + struct pcie_link_state *link, *parent_link; if (!parent || !parent->link_state) return; @@ -1016,7 +1016,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) goto out; link = parent->link_state; - root = link->root; + root_dev = pcie_get_root(link->pdev); parent_dev = pci_get_parent(link->pdev); parent_link = parent_dev ? parent_dev->link_state : NULL; @@ -1028,7 +1028,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) /* Recheck latencies and configure upstream links */ if (parent_link) { - pcie_update_aspm_capable(root); + pcie_update_aspm_capable(root_dev->link_state); pcie_config_aspm_path(parent_link); } out: @@ -1040,6 +1040,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) void pcie_aspm_pm_state_change(struct pci_dev *pdev) { struct pcie_link_state *link = pdev->link_state; + struct pci_dev *root = pcie_get_root(pdev); if (aspm_disabled || !link) return; @@ -1049,7 +1050,7 @@ void pcie_aspm_pm_state_change(struct pci_dev *pdev) */ down_read(&pci_bus_sem); mutex_lock(&aspm_lock); - pcie_update_aspm_capable(link->root); + pcie_update_aspm_capable(root->link_state); pcie_config_aspm_path(link); mutex_unlock(&aspm_lock); up_read(&pci_bus_sem);