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 80BD2C433EF for ; Tue, 21 Dec 2021 12:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237377AbhLUMEm (ORCPT ); Tue, 21 Dec 2021 07:04:42 -0500 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]:42982 "EHLO out30-133.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230184AbhLUMEl (ORCPT ); Tue, 21 Dec 2021 07:04:41 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=jkchen@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0V.KzN23_1640088278; Received: from localhost(mailfrom:jkchen@linux.alibaba.com fp:SMTPD_---0V.KzN23_1640088278) by smtp.aliyun-inc.com(127.0.0.1); Tue, 21 Dec 2021 20:04:38 +0800 From: Jay Chen To: mathieu.poirier@linaro.org, suzuki.poulose@arm.com, leo.yan@linaro.org, alexander.shishkin@linux.intel.com, linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org, linux-kernel@vger.kernel.org Cc: zhangliguang@linux.alibaba.com Subject: [RFC V3 PATCH] coresight: change tmc from misc device to cdev device Date: Tue, 21 Dec 2021 20:04:37 +0800 Message-Id: <20211221120437.4781-1-jkchen@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, there are 130 etr and etf on our machine, but the current coresight tmc driver uses misc_register to register the device, which leads to the error that the device number is not enough. coresight-tmc: probe of xxxxx failed with error -16 This patch changes the device registration method to cdev's dynamic registration method to solve the problem of insufficient device numbers. Signed-off-by: Jay Chen --- .../hwtracing/coresight/coresight-tmc-core.c | 91 +++++++++++++++---- drivers/hwtracing/coresight/coresight-tmc.h | 10 +- 2 files changed, 83 insertions(+), 18 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index d0276af82494..0d51071e9f88 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -31,6 +31,12 @@ DEFINE_CORESIGHT_DEVLIST(etb_devs, "tmc_etb"); DEFINE_CORESIGHT_DEVLIST(etf_devs, "tmc_etf"); DEFINE_CORESIGHT_DEVLIST(etr_devs, "tmc_etr"); +static DEFINE_IDA(tmc_ida); +static dev_t tmc_major; +static struct class *tmc_class; + +#define TMC_DEV_MAX (MINORMASK + 1) + void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata) { struct coresight_device *csdev = drvdata->csdev; @@ -147,7 +153,7 @@ static int tmc_open(struct inode *inode, struct file *file) { int ret; struct tmc_drvdata *drvdata = container_of(file->private_data, - struct tmc_drvdata, miscdev); + struct tmc_drvdata, cdev); ret = tmc_read_prepare(drvdata); if (ret) @@ -179,7 +185,7 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len, char *bufp; ssize_t actual; struct tmc_drvdata *drvdata = container_of(file->private_data, - struct tmc_drvdata, miscdev); + struct tmc_drvdata, cdev); actual = tmc_get_sysfs_trace(drvdata, *ppos, len, &bufp); if (actual <= 0) return 0; @@ -200,7 +206,7 @@ static int tmc_release(struct inode *inode, struct file *file) { int ret; struct tmc_drvdata *drvdata = container_of(file->private_data, - struct tmc_drvdata, miscdev); + struct tmc_drvdata, cdev); ret = tmc_read_unprepare(drvdata); if (ret) @@ -451,6 +457,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) { int ret = 0; u32 devid; + dev_t devt; void __iomem *base; struct device *dev = &adev->dev; struct coresight_platform_data *pdata = NULL; @@ -546,14 +553,32 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) goto out; } - drvdata->miscdev.name = desc.name; - drvdata->miscdev.minor = MISC_DYNAMIC_MINOR; - drvdata->miscdev.fops = &tmc_fops; - ret = misc_register(&drvdata->miscdev); + ret = ida_simple_get(&tmc_ida, 0, TMC_DEV_MAX, GFP_KERNEL); + if (ret < 0) + goto err_coresight_unregister; + + cdev_init(&drvdata->cdev.cdev, &tmc_fops); + drvdata->cdev.cdev.owner = THIS_MODULE; + devt = MKDEV(MAJOR(tmc_major), ret); + ret = cdev_add(&drvdata->cdev.cdev, devt, 1); if (ret) - coresight_unregister(drvdata->csdev); - else + goto err_free_tmc_ida; + + drvdata->cdev.dev = device_create(tmc_class, NULL, devt, &drvdata->cdev, desc.name); + if (IS_ERR(drvdata->cdev.dev)) { + ret = PTR_ERR(drvdata->cdev.dev); + goto err_delete_cdev; + } else pm_runtime_put(&adev->dev); + + return 0; + +err_delete_cdev: + cdev_del(&drvdata->cdev.cdev); +err_free_tmc_ida: + ida_simple_remove(&tmc_ida, MINOR(devt)); +err_coresight_unregister: + coresight_unregister(drvdata->csdev); out: return ret; } @@ -583,13 +608,11 @@ static void tmc_shutdown(struct amba_device *adev) static void tmc_remove(struct amba_device *adev) { struct tmc_drvdata *drvdata = dev_get_drvdata(&adev->dev); + struct device *dev = drvdata->cdev.dev; - /* - * Since misc_open() holds a refcount on the f_ops, which is - * etb fops in this case, device is there until last file - * handler to this device is closed. - */ - misc_deregister(&drvdata->miscdev); + ida_simple_remove(&tmc_ida, dev->devt); + device_destroy(tmc_class, dev->devt); + cdev_del(&drvdata->cdev.cdev); coresight_unregister(drvdata->csdev); } @@ -618,7 +641,43 @@ static struct amba_driver tmc_driver = { .id_table = tmc_ids, }; -module_amba_driver(tmc_driver); +static int __init tmc_init(void) +{ + int ret; + + ret = alloc_chrdev_region(&tmc_major, 0, TMC_DEV_MAX, "tmc"); + if (ret < 0) { + pr_err("tmc: failed to allocate char dev region\n"); + return ret; + } + + tmc_class = class_create(THIS_MODULE, "tmc"); + if (IS_ERR(tmc_class)) { + pr_err("tmc: failed to create class\n"); + ret = PTR_ERR(tmc_class); + unregister_chrdev_region(tmc_major, TMC_DEV_MAX); + return ret; + } + + ret = amba_driver_register(&tmc_driver); + if (ret) { + pr_err("tmc: error registering amba driver\n"); + class_destroy(tmc_class); + unregister_chrdev_region(tmc_major, TMC_DEV_MAX); + } + + return ret; +} + +static void __exit tmc_exit(void) +{ + amba_driver_unregister(&tmc_driver); + class_destroy(tmc_class); + unregister_chrdev_region(tmc_major, TMC_DEV_MAX); +} + +module_init(tmc_init); +module_exit(tmc_exit); MODULE_AUTHOR("Pratik Patel "); MODULE_DESCRIPTION("Arm CoreSight Trace Memory Controller driver"); diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 6bec20a392b3..b65ac363f9e4 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -7,6 +7,7 @@ #ifndef _CORESIGHT_TMC_H #define _CORESIGHT_TMC_H +#include #include #include #include @@ -163,11 +164,16 @@ struct etr_buf { void *private; }; +struct tmc_cdev { + struct cdev cdev; + struct device *dev; +}; + /** * struct tmc_drvdata - specifics associated to an TMC component * @base: memory mapped base address for this component. * @csdev: component vitals needed by the framework. - * @miscdev: specifics to handle "/dev/xyz.tmc" entry. + * @tmc_cdev: specifics to handle "/dev/xyz.tmc" entry. * @spinlock: only one at a time pls. * @pid: Process ID of the process being monitored by the session * that is using this component. @@ -191,7 +197,7 @@ struct etr_buf { struct tmc_drvdata { void __iomem *base; struct coresight_device *csdev; - struct miscdevice miscdev; + struct tmc_cdev cdev; spinlock_t spinlock; pid_t pid; bool reading; -- 2.27.0