From patchwork Tue Dec 29 08:43:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Loic Poulain X-Patchwork-Id: 11992059 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6921C433E0 for ; Tue, 29 Dec 2020 08:38:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 868B720798 for ; Tue, 29 Dec 2020 08:38:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726261AbgL2Ihs (ORCPT ); Tue, 29 Dec 2020 03:37:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726129AbgL2Ihr (ORCPT ); Tue, 29 Dec 2020 03:37:47 -0500 Received: from mail-ej1-x62d.google.com (mail-ej1-x62d.google.com [IPv6:2a00:1450:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2534FC06179B for ; Tue, 29 Dec 2020 00:36:31 -0800 (PST) Received: by mail-ej1-x62d.google.com with SMTP id 6so17221891ejz.5 for ; Tue, 29 Dec 2020 00:36:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=A8ghSZC0o/frzSbWNus1KBuo0kNzFEb9nrR9JTZVUY8=; b=MDcWJizkIpg/w9k2gJNde+gWLWIPadndsbNNyD7ojx2YgxotymnlPDAiqnXi4voVhM 47qV/3bHeQoBKZsTasCrcC78s4actgYDxwlo9/KFAqLUK/GhkDH7YhlacgCBvHpxD8uT QKPL7ZhQpmkh8TL9fCalWCLW1rF4QkMY6stx8BVyxH6i5GJd6VZhDZAhqcaHkNK7vRfW gXWmEpUhIbCRZrJIOafq48ui61ih01jkbthArq5NC8ah9RRMHxJXtVxmh0gTwt+NNXUL cfo0Xhk0tyM+ZFAo9ndDNxExOk5pnejBWOTcQoZTNvhnphpdeY7YBOvfHnQyGK3URzSL uVMQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=A8ghSZC0o/frzSbWNus1KBuo0kNzFEb9nrR9JTZVUY8=; b=rG4xiIipTvEEHWec1/126YYJTziujCYOmr/AS1xAWh7W0RmMMx4M1585MlHFOFu4vT +p0URoYY2L0VxvLvpXiLGI8sSBuI2RG4Zv0Pif9CCPpAa/V0QHSyxNx7XuxptNdN/H1Z S7RTtxkM5JZ50XPjaaUL2KxuvcEsofiK83fQuslYLGhnQPT7STknReqP/txHKzLBagOZ 3Z7YdQv6namZMqXuDwhM9ZN85iGlHNuT/CI6+SVzqDFkdORf627Z9d7/NHPlHIjoVkN2 XOkC1qdUfiwvpgiBwdhGlArUCMsLegX9hvfvOtXv4fNTNXnbCFbWY+gpxFdirHSHhnhB 3b4A== X-Gm-Message-State: AOAM533/BQFAqJPakQFofDIahsOHrmWmH+gMmiu//MLwvtHutw9YdHfm 0tNm7QzqAEjF3QGv3P6HgtA69g== X-Google-Smtp-Source: ABdhPJwk+jxjw5vS/vS4kHzaWSHSr2UW1V4PgSphs47EbzWwb8ueJeD94rEaC/jYYp6dwx5O02SCaA== X-Received: by 2002:a17:906:a015:: with SMTP id p21mr36438724ejy.49.1609230989885; Tue, 29 Dec 2020 00:36:29 -0800 (PST) Received: from localhost.localdomain ([2a01:e0a:490:8730:6f69:290a:2b46:b9]) by smtp.gmail.com with ESMTPSA id c23sm37265143eds.88.2020.12.29.00.36.29 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 29 Dec 2020 00:36:29 -0800 (PST) From: Loic Poulain To: manivannan.sadhasivam@linaro.org Cc: linux-arm-msm@vger.kernel.org, bbhatt@codeaurora.org, hemantk@codeaurora.org, Loic Poulain Subject: [PATCH v6 05/10] mhi: pci_generic: Add support for reset Date: Tue, 29 Dec 2020 09:43:46 +0100 Message-Id: <1609231431-10048-6-git-send-email-loic.poulain@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1609231431-10048-1-git-send-email-loic.poulain@linaro.org> References: <1609231431-10048-1-git-send-email-loic.poulain@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Add support for resetting the device, reset can be triggered in case of error or manually via sysfs (/sys/bus/pci/devices/*/reset). Signed-off-by: Loic Poulain --- drivers/bus/mhi/pci_generic.c | 121 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 108 insertions(+), 13 deletions(-) diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c index 077595c..2521cd4 100644 --- a/drivers/bus/mhi/pci_generic.c +++ b/drivers/bus/mhi/pci_generic.c @@ -8,6 +8,7 @@ * Copyright (C) 2020 Linaro Ltd */ +#include #include #include #include @@ -15,6 +16,7 @@ #define MHI_PCI_DEFAULT_BAR_NUM 0 +#define MHI_POST_RESET_DELAY_MS 500 /** * struct mhi_pci_dev_info - MHI PCI device specific information * @config: MHI controller configuration @@ -177,6 +179,16 @@ static const struct pci_device_id mhi_pci_id_table[] = { }; MODULE_DEVICE_TABLE(pci, mhi_pci_id_table); +enum mhi_pci_device_status { + MHI_PCI_DEV_STARTED, +}; + +struct mhi_pci_device { + struct mhi_controller mhi_cntrl; + struct pci_saved_state *pci_state; + unsigned long status; +}; + static int mhi_pci_read_reg(struct mhi_controller *mhi_cntrl, void __iomem *addr, u32 *out) { @@ -196,6 +208,20 @@ static void mhi_pci_status_cb(struct mhi_controller *mhi_cntrl, /* Nothing to do for now */ } +static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl) +{ + struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev); + u16 vendor = 0; + + if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor)) + return false; + + if (vendor == (u16) ~0 || vendor == 0) + return false; + + return true; +} + static int mhi_pci_claim(struct mhi_controller *mhi_cntrl, unsigned int bar_num, u64 dma_mask) { @@ -291,16 +317,20 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { const struct mhi_pci_dev_info *info = (struct mhi_pci_dev_info *) id->driver_data; const struct mhi_controller_config *mhi_cntrl_config; + struct mhi_pci_device *mhi_pdev; struct mhi_controller *mhi_cntrl; int err; dev_dbg(&pdev->dev, "MHI PCI device found: %s\n", info->name); - mhi_cntrl = mhi_alloc_controller(); - if (!mhi_cntrl) + mhi_pdev = devm_kzalloc(&pdev->dev, sizeof(*mhi_pdev), GFP_KERNEL); + if (!mhi_pdev) return -ENOMEM; mhi_cntrl_config = info->config; + mhi_cntrl = &mhi_pdev->mhi_cntrl; + + mhi_initialize_controller(mhi_cntrl); mhi_cntrl->cntrl_dev = &pdev->dev; mhi_cntrl->iova_start = 0; mhi_cntrl->iova_stop = DMA_BIT_MASK(info->dma_data_width); @@ -315,17 +345,21 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) err = mhi_pci_claim(mhi_cntrl, info->bar_num, DMA_BIT_MASK(info->dma_data_width)); if (err) - goto err_release; + return err; err = mhi_pci_get_irqs(mhi_cntrl, mhi_cntrl_config); if (err) - goto err_release; + return err; + + pci_set_drvdata(pdev, mhi_pdev); - pci_set_drvdata(pdev, mhi_cntrl); + /* Have stored pci confspace at hand for restore in sudden PCI error */ + pci_save_state(pdev); + mhi_pdev->pci_state = pci_store_saved_state(pdev); err = mhi_register_controller(mhi_cntrl, mhi_cntrl_config); if (err) - goto err_release; + return err; /* MHI bus does not power up the controller by default */ err = mhi_prepare_for_power_up(mhi_cntrl); @@ -340,33 +374,94 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) goto err_unprepare; } + set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status); + return 0; err_unprepare: mhi_unprepare_after_power_down(mhi_cntrl); err_unregister: mhi_unregister_controller(mhi_cntrl); -err_release: - mhi_free_controller(mhi_cntrl); return err; } static void mhi_pci_remove(struct pci_dev *pdev) { - struct mhi_controller *mhi_cntrl = pci_get_drvdata(pdev); + struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev); + struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl; + + if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) { + mhi_power_down(mhi_cntrl, true); + mhi_unprepare_after_power_down(mhi_cntrl); + } - mhi_power_down(mhi_cntrl, true); - mhi_unprepare_after_power_down(mhi_cntrl); mhi_unregister_controller(mhi_cntrl); - mhi_free_controller(mhi_cntrl); } +static void mhi_pci_reset_prepare(struct pci_dev *pdev) +{ + struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev); + struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl; + + dev_info(&pdev->dev, "reset\n"); + + /* Clean up MHI state */ + if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) { + mhi_power_down(mhi_cntrl, false); + mhi_unprepare_after_power_down(mhi_cntrl); + } + + /* cause internal device reset */ + mhi_reg_soc_reset(mhi_cntrl); + + /* Be sure device reset has been executed */ + msleep(MHI_POST_RESET_DELAY_MS); +} + +static void mhi_pci_reset_done(struct pci_dev *pdev) +{ + struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev); + struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl; + int err; + + /* Restore initial known working PCI state */ + pci_load_saved_state(pdev, mhi_pdev->pci_state); + pci_restore_state(pdev); + + /* Is device status available ? */ + if (!mhi_pci_is_alive(mhi_cntrl)) { + dev_err(&pdev->dev, "reset failed\n"); + return; + } + + err = mhi_prepare_for_power_up(mhi_cntrl); + if (err) { + dev_err(&pdev->dev, "failed to prepare MHI controller\n"); + return; + } + + err = mhi_sync_power_up(mhi_cntrl); + if (err) { + dev_err(&pdev->dev, "failed to power up MHI controller\n"); + mhi_unprepare_after_power_down(mhi_cntrl); + return; + } + + set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status); +} + +static const struct pci_error_handlers mhi_pci_err_handler = { + .reset_prepare = mhi_pci_reset_prepare, + .reset_done = mhi_pci_reset_done, +}; + static struct pci_driver mhi_pci_driver = { .name = "mhi-pci-generic", .id_table = mhi_pci_id_table, .probe = mhi_pci_probe, - .remove = mhi_pci_remove + .remove = mhi_pci_remove, + .err_handler = &mhi_pci_err_handler, }; module_pci_driver(mhi_pci_driver);