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 A7E24C27C76 for ; Wed, 25 Jan 2023 04:45:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233206AbjAYEpv (ORCPT ); Tue, 24 Jan 2023 23:45:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229625AbjAYEpu (ORCPT ); Tue, 24 Jan 2023 23:45:50 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B31F2ED66; Tue, 24 Jan 2023 20:45:48 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id BA1A6CE1D44; Wed, 25 Jan 2023 04:45:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FC13C433D2; Wed, 25 Jan 2023 04:45:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674621945; bh=Dmy/U9fo/mqtr/+FTl0CBDlldoCyty4SXY9s0DQ4cug=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=c1fyofug7k16C+T1NDBYF8M30zrqjxlIt1WTbfSHsD34mDBqz3AxGdjZwC+HF3k6U yAtj3/41ovDrkI1/BOJTvTDUKMxak181a5qF5FmscuNLGH1c7Qm58/h1XiE+V2eEs0 a3S2L52NZY1fNzb7vF4dcvGPU1LvpUPw12QnPr9otASE4ezl5pEjyUX9G/zqMsPzFF +UGSFXLbe2BCMhcXDoS+JjDLVqbW2qTkGIHb6H+r8d8v1h58vcS9zwSe1n8Gv5Vx8n yXqqcSKH0M5Emy8GrFvU7Z91kv/ZTskVmtJTMdFvKzPNlAbfLX7dcIJe5kuURbbAZZ jR+rT9N+cyNdA== Date: Tue, 24 Jan 2023 20:45:43 -0800 From: Jakub Kicinski To: Bjorn Helgaas Cc: m.chetan.kumar@linux.intel.com, netdev@vger.kernel.org, davem@davemloft.net, johannes@sipsolutions.net, ryazanov.s.a@gmail.com, loic.poulain@linaro.org, ilpo.jarvinen@linux.intel.com, ricardo.martinez@linux.intel.com, chiranjeevi.rapolu@linux.intel.com, haijun.liu@mediatek.com, edumazet@google.com, pabeni@redhat.com, chandrashekar.devegowda@intel.com, linuxwwan@intel.com, linuxwwan_5g@intel.com, Madhusmita Sahu , linux-pci@vger.kernel.org Subject: Re: [PATCH v5 net-next 3/5] net: wwan: t7xx: PCIe reset rescan Message-ID: <20230124204543.550d88e3@kernel.org> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Bjorn, any objections to the kind of shenanigans this is playing? On Sat, 21 Jan 2023 19:03:23 +0530 m.chetan.kumar@linux.intel.com wrote: > From: M Chetan Kumar > > PCI rescan module implements "rescan work queue". > In firmware flashing or coredump collection procedure > WWAN device is programmed to boot in fastboot mode and > a work item is scheduled for removal & detection. > > The WWAN device is reset using APCI call as part driver > removal flow. Work queue rescans pci bus at fixed interval > for device detection, later when device is detect work queue > exits. > > Signed-off-by: Haijun Liu > Co-developed-by: Madhusmita Sahu > Signed-off-by: Madhusmita Sahu > Signed-off-by: Ricardo Martinez > Signed-off-by: M Chetan Kumar > Signed-off-by: Devegowda Chandrashekar > -- > v5: > * No Change. > v4: > * Change "is still exist" to "still exists". > v3: > * No Change. > v2: > * Drop empty line inside critical sections. > * Correct log message. > * Correct logic inside t7xx_always_match(). > * Drop hp_enable changes. > * Drop g_ prefix from t7xx_rescan_ctx. > * Use tab before comment in struct decl. > * Remove extra white space. > * Drop modem exception state check. > * Crit section newlines. > * Remove unnecessary header files inclusion. > * Drop spinlock around reset and rescan flow. > --- > drivers/net/wwan/t7xx/Makefile | 3 +- > drivers/net/wwan/t7xx/t7xx_modem_ops.c | 3 + > drivers/net/wwan/t7xx/t7xx_pci.c | 56 ++++++++++++++- > drivers/net/wwan/t7xx/t7xx_pci_rescan.c | 96 +++++++++++++++++++++++++ > drivers/net/wwan/t7xx/t7xx_pci_rescan.h | 28 ++++++++ > 5 files changed, 184 insertions(+), 2 deletions(-) > create mode 100644 drivers/net/wwan/t7xx/t7xx_pci_rescan.c > create mode 100644 drivers/net/wwan/t7xx/t7xx_pci_rescan.h > > diff --git a/drivers/net/wwan/t7xx/Makefile b/drivers/net/wwan/t7xx/Makefile > index 268ff9e87e5b..ba5c607404a4 100644 > --- a/drivers/net/wwan/t7xx/Makefile > +++ b/drivers/net/wwan/t7xx/Makefile > @@ -17,7 +17,8 @@ mtk_t7xx-y:= t7xx_pci.o \ > t7xx_hif_dpmaif_tx.o \ > t7xx_hif_dpmaif_rx.o \ > t7xx_dpmaif.o \ > - t7xx_netdev.o > + t7xx_netdev.o \ > + t7xx_pci_rescan.o > > mtk_t7xx-$(CONFIG_WWAN_DEBUGFS) += \ > t7xx_port_trace.o \ > diff --git a/drivers/net/wwan/t7xx/t7xx_modem_ops.c b/drivers/net/wwan/t7xx/t7xx_modem_ops.c > index cbd65aa48721..2fcaea4694ba 100644 > --- a/drivers/net/wwan/t7xx/t7xx_modem_ops.c > +++ b/drivers/net/wwan/t7xx/t7xx_modem_ops.c > @@ -37,6 +37,7 @@ > #include "t7xx_modem_ops.h" > #include "t7xx_netdev.h" > #include "t7xx_pci.h" > +#include "t7xx_pci_rescan.h" > #include "t7xx_pcie_mac.h" > #include "t7xx_port.h" > #include "t7xx_port_proxy.h" > @@ -194,6 +195,8 @@ static irqreturn_t t7xx_rgu_isr_thread(int irq, void *data) > > msleep(RGU_RESET_DELAY_MS); > t7xx_reset_device_via_pmic(t7xx_dev); > + t7xx_rescan_queue_work(t7xx_dev->pdev); > + > return IRQ_HANDLED; > } > > diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c b/drivers/net/wwan/t7xx/t7xx_pci.c > index 871f2a27a398..3f5ebbc11b82 100644 > --- a/drivers/net/wwan/t7xx/t7xx_pci.c > +++ b/drivers/net/wwan/t7xx/t7xx_pci.c > @@ -38,6 +38,7 @@ > #include "t7xx_mhccif.h" > #include "t7xx_modem_ops.h" > #include "t7xx_pci.h" > +#include "t7xx_pci_rescan.h" > #include "t7xx_pcie_mac.h" > #include "t7xx_reg.h" > #include "t7xx_state_monitor.h" > @@ -715,6 +716,7 @@ static int t7xx_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > return ret; > } > > + t7xx_rescan_done(); > t7xx_pcie_mac_set_int(t7xx_dev, MHCCIF_INT); > t7xx_pcie_mac_interrupts_en(t7xx_dev); > > @@ -754,7 +756,59 @@ static struct pci_driver t7xx_pci_driver = { > .shutdown = t7xx_pci_shutdown, > }; > > -module_pci_driver(t7xx_pci_driver); > +static int __init t7xx_pci_init(void) > +{ > + int ret; > + > + t7xx_pci_dev_rescan(); > + ret = t7xx_rescan_init(); > + if (ret) { > + pr_err("Failed to init t7xx rescan work\n"); > + return ret; > + } > + > + return pci_register_driver(&t7xx_pci_driver); > +} > +module_init(t7xx_pci_init); > + > +static int t7xx_always_match(struct device *dev, const void *data) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > + const struct pci_device_id *id = data; > + > + if (pci_match_id(id, pdev)) > + return 1; > + > + return 0; > +} > + > +static void __exit t7xx_pci_cleanup(void) > +{ > + int remove_flag = 0; > + struct device *dev; > + > + dev = driver_find_device(&t7xx_pci_driver.driver, NULL, &t7xx_pci_table[0], > + t7xx_always_match); > + if (dev) { > + pr_debug("unregister t7xx PCIe driver while device still exists.\n"); > + put_device(dev); > + remove_flag = 1; > + } else { > + pr_debug("no t7xx PCIe driver found.\n"); > + } > + > + pci_lock_rescan_remove(); > + pci_unregister_driver(&t7xx_pci_driver); > + pci_unlock_rescan_remove(); > + > + t7xx_rescan_deinit(); > + if (remove_flag) { > + pr_debug("remove t7xx PCI device\n"); > + pci_stop_and_remove_bus_device_locked(to_pci_dev(dev)); > + } > +} > + > +module_exit(t7xx_pci_cleanup); > > MODULE_AUTHOR("MediaTek Inc"); > MODULE_DESCRIPTION("MediaTek PCIe 5G WWAN modem T7xx driver"); > diff --git a/drivers/net/wwan/t7xx/t7xx_pci_rescan.c b/drivers/net/wwan/t7xx/t7xx_pci_rescan.c > new file mode 100644 > index 000000000000..67f13c035846 > --- /dev/null > +++ b/drivers/net/wwan/t7xx/t7xx_pci_rescan.c > @@ -0,0 +1,96 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2021, MediaTek Inc. > + * Copyright (c) 2021-2023, Intel Corporation. > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ":t7xx:%s: " fmt, __func__ > +#define dev_fmt(fmt) "t7xx: " fmt > + > +#include > +#include > +#include > +#include > + > +#include "t7xx_pci.h" > +#include "t7xx_pci_rescan.h" > + > +static struct remove_rescan_context t7xx_rescan_ctx; > + > +void t7xx_pci_dev_rescan(void) > +{ > + struct pci_bus *b = NULL; > + > + pci_lock_rescan_remove(); > + while ((b = pci_find_next_bus(b))) > + pci_rescan_bus(b); > + pci_unlock_rescan_remove(); > +} > + > +void t7xx_rescan_done(void) > +{ > + if (!atomic_read(&t7xx_rescan_ctx.rescan_done)) { > + atomic_set(&t7xx_rescan_ctx.rescan_done, 1); > + pr_debug("Rescan probe\n"); > + } else { > + pr_debug("Init probe\n"); > + } > +} > + > +static void t7xx_remove_rescan(struct work_struct *work) > +{ > + int num_retries = RESCAN_RETRIES; > + struct pci_dev *pdev; > + > + atomic_set(&t7xx_rescan_ctx.rescan_done, 0); > + pdev = t7xx_rescan_ctx.dev; > + > + if (pdev) { > + pci_stop_and_remove_bus_device_locked(pdev); > + pr_debug("start remove and rescan flow\n"); > + } > + > + do { > + t7xx_pci_dev_rescan(); > + > + if (atomic_read(&t7xx_rescan_ctx.rescan_done)) > + break; > + > + msleep(DELAY_RESCAN_MTIME); > + } while (num_retries--); > +} > + > +void t7xx_rescan_queue_work(struct pci_dev *pdev) > +{ > + if (!atomic_read(&t7xx_rescan_ctx.rescan_done)) { > + dev_err(&pdev->dev, "Rescan failed\n"); > + return; > + } > + > + t7xx_rescan_ctx.dev = pdev; > + queue_work(t7xx_rescan_ctx.pcie_rescan_wq, &t7xx_rescan_ctx.service_task); > +} > + > +int t7xx_rescan_init(void) > +{ > + atomic_set(&t7xx_rescan_ctx.rescan_done, 1); > + t7xx_rescan_ctx.dev = NULL; > + > + t7xx_rescan_ctx.pcie_rescan_wq = create_singlethread_workqueue(MTK_RESCAN_WQ); > + if (!t7xx_rescan_ctx.pcie_rescan_wq) { > + pr_err("Failed to create workqueue: %s\n", MTK_RESCAN_WQ); > + return -ENOMEM; > + } > + > + INIT_WORK(&t7xx_rescan_ctx.service_task, t7xx_remove_rescan); > + > + return 0; > +} > + > +void t7xx_rescan_deinit(void) > +{ > + t7xx_rescan_ctx.dev = NULL; > + atomic_set(&t7xx_rescan_ctx.rescan_done, 0); > + cancel_work_sync(&t7xx_rescan_ctx.service_task); > + destroy_workqueue(t7xx_rescan_ctx.pcie_rescan_wq); > +} > diff --git a/drivers/net/wwan/t7xx/t7xx_pci_rescan.h b/drivers/net/wwan/t7xx/t7xx_pci_rescan.h > new file mode 100644 > index 000000000000..80b25c44151c > --- /dev/null > +++ b/drivers/net/wwan/t7xx/t7xx_pci_rescan.h > @@ -0,0 +1,28 @@ > +/* SPDX-License-Identifier: GPL-2.0-only > + * > + * Copyright (c) 2021, MediaTek Inc. > + * Copyright (c) 2021-2023, Intel Corporation. > + */ > + > +#ifndef __T7XX_PCI_RESCAN_H__ > +#define __T7XX_PCI_RESCAN_H__ > + > +#define MTK_RESCAN_WQ "mtk_rescan_wq" > + > +#define DELAY_RESCAN_MTIME 1000 > +#define RESCAN_RETRIES 35 > + > +struct remove_rescan_context { > + struct work_struct service_task; > + struct workqueue_struct *pcie_rescan_wq; > + struct pci_dev *dev; > + atomic_t rescan_done; > +}; > + > +void t7xx_pci_dev_rescan(void); > +void t7xx_rescan_queue_work(struct pci_dev *pdev); > +int t7xx_rescan_init(void); > +void t7xx_rescan_deinit(void); > +void t7xx_rescan_done(void); > + > +#endif /* __T7XX_PCI_RESCAN_H__ */