From patchwork Sun Nov 7 16:29:39 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: 12606847 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 7634FC433EF for ; Sun, 7 Nov 2021 16:30:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5AC5D6008E for ; Sun, 7 Nov 2021 16:30:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235796AbhKGQcn (ORCPT ); Sun, 7 Nov 2021 11:32:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235787AbhKGQcl (ORCPT ); Sun, 7 Nov 2021 11:32:41 -0500 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89411C061714; Sun, 7 Nov 2021 08:29:58 -0800 (PST) Received: by mail-ed1-x52c.google.com with SMTP id v11so50205644edc.9; Sun, 07 Nov 2021 08:29:58 -0800 (PST) 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=mdiJ7lzX3Ms7UkaPuy+L6z/d3dXtyRjWewegyVGznlA=; b=I5rEqpyCm3FkQBtSl4whncXDqjF4h4SOtN8F7XPh51lTJOp+2uoMfXXZVNf67owu1i elg6SyGq9MySmTCnA0ndGZ3RCZecGuGTn3noBhDgPFVSgRvnU9rcT8SJQlQ8FIqOMncl btBgWxhI4DC9odwwgYacSVvQkpsusB1Vp6tpqJ9RCuzPytxpzFPzplCT/dZaSDs+hhuy 9RoXheSibld/cnPUC2yxvzu5jz1zOz/GraM0C9Y8IMY96wLYy8hxBcWy0H6KH4HynkKk sElH7JNAHI+sKkpLLEJuFnDnDWlW1xMlMFNbxAG/xsjEbdUxTRA5eVkwlvH+anRUzShV JccA== 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=mdiJ7lzX3Ms7UkaPuy+L6z/d3dXtyRjWewegyVGznlA=; b=7OOto1lgT+orzLTby5/8QEFXx/kLYqpDl8om/Lh0ZnJEclgze7RD7BPEr5wd/j0YkV T0YLGPByerOFNsdfgen6QOv4sTTqqruNmzWXlu5Xov1QqzY9gKEjIhPx6P2FOg5BCYNk BHXZKIu2ShXT+g3FVishnkQqpY60ivrL9Kz7tjAWYv9lYT4vcZJQIWnStyR0+cSQWeld QiJrqFvvG0FM6GvpcqWPDu3aFV54TfHjyGACFWWTC55XyRKa16jNbwAKqwulKlfVW9+Z B3QlI2JwbFYCaLAc3gFvtDEoialGDJXa9fU8/tIdD2DY6I7wPyv7gQsgh5wSIeTbl9KF 7FWg== X-Gm-Message-State: AOAM532pJYgnNs9Fusq4d3eYXGc19gm5mOdLe4Ti9UhQ3/XkcELQxTXU xaE3pv+Qt7Aoq5NSTGNW0WU= X-Google-Smtp-Source: ABdhPJysDRtCZ1K520GPRXrESIeAxSOLHWwDJPUV3YWakVOE36W4aCfuJC/XJhcbpco1Z0NwoR/Cnw== X-Received: by 2002:a17:907:168f:: with SMTP id hc15mr4100256ejc.115.1636302597058; Sun, 07 Nov 2021 08:29:57 -0800 (PST) Received: from localhost.localdomain ([2a02:ab88:109:9f0:f6a6:7fbe:807a:e1cc]) by smtp.googlemail.com with ESMTPSA id hq37sm7195270ejc.116.2021.11.07.08.29.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 07 Nov 2021 08:29:56 -0800 (PST) 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 v4 3/5] PCI/ASPM: Remove struct pcie_link_state.root Date: Sun, 7 Nov 2021 17:29:39 +0100 Message-Id: <20211107162941.1196-4-refactormyself@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20211107162941.1196-1-refactormyself@gmail.com> References: <20211107162941.1196-1-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 calculated within alloc_pcie_link_state() and stored in struct pcie_link_state.root. If this calculation is extracted out, it make it possible to avoid storing the value - extract the calculations of pcie_link_state->root into pcie_get_root(). - remove *root* from the struct pcie_link_state. - replace references to struct pcie_link_state.root with a call to pcie_get_root(). Signed-off-by: Saheed O. Bolarinwa --- drivers/pci/pcie/aspm.c | 68 +++++++++++++++++++++-------------------- 1 file changed, 35 insertions(+), 33 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 75618302fb87..90c7a0b379f4 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 pcie_link_state *uplink_bridge = pcie_upstream_link(pdev); + + if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT || + pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE || !uplink_bridge) { + return pdev; + } else { + return pcie_get_root(uplink_bridge->pdev); + } +} + 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 pcie_link_state *uplink_bridge; - - uplink_bridge = pcie_upstream_link(pdev); - if (!uplink_bridge) { - kfree(link); - return NULL; - } - - link->root = ulink_bridge->root; - } - list_add(&link->sibling, &link_list); pdev->link_state = link; return link; @@ -972,20 +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 pcie_link_state *uplink = pcie_upstream_link(root->pdev); + struct pci_dev *dev, *root_dev; - root = uplink ? uplink->root : root; + /* Ensure it is the root device */ + root_dev = pcie_get_root(root->pdev); + root = root_dev ? root_dev->link_state : root; 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)) @@ -998,8 +999,8 @@ 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 = pdev->bus->self; - struct pcie_link_state *link, *root, *uplink_bridge; + struct pci_dev *root_dev, *parent = pdev->bus->self; + struct pcie_link_state *link, *uplink_bridge; if (!parent || !parent->link_state) return; @@ -1014,7 +1015,7 @@ 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); uplink_bridge = pcie_upstream_link(link->pdev); /* All functions are removed, so just disable ASPM for the link */ @@ -1025,7 +1026,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) /* Recheck latencies and configure upstream links */ if (uplink_bridge) { - pcie_update_aspm_capable(root); + pcie_update_aspm_capable(root_dev->link_state); pcie_config_aspm_path(uplink_bridge); } out: @@ -1037,6 +1038,7 @@ 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; @@ -1046,7 +1048,7 @@ 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);