[RESEND PATCH v2] coresight: change tmc from misc device to cdev device
Jiankang Chen
jkchen at linux.alibaba.com
Thu Jan 13 22:32:49 PST 2022
在 2022/1/14 12:55, Mathieu Poirier 写道:
> On Thu, 13 Jan 2022 at 20:16, Jiankang Chen <jkchen at linux.alibaba.com> wrote:
>> Hi Mathieu
>>
>> 在 2022/1/14 00:56, Mathieu Poirier 写道:
>>> On Wed, 12 Jan 2022 at 23:12, Jay Chen <jkchen at linux.alibaba.com> wrote:
>>>> 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.
>>> On December 21st you posted this patch with a "RFC V3 PATCH" tag. On
>>> January 5th you posted a new version with a simple "PATCH" tag which,
>>> minutes later, was superseded by another patch labelled "RESEND
>>> PATCH". Today you're sending yet another revision labelled "RESEND
>>> PATCH V2"...
>>>
>>> Is it a "V2" of the "RESEND PATCH" that was a new revision of the "RFC
>>> V3 PATCH"? Are you confused? I certainly am...
>>>
>> this patch v2 is a new version，and it fix some bugs;
>>
> How can it be a V2 when a V3 has already been published? I will not
> review this patch, and even less apply it, until it is properly
> labelled.
>
OK, I'm going to revise the label and then send it
Thanks
Jay
>> sorry
>>
>> jay
>>
>>>> Signed-off-by: Jay Chen <jkchen at linux.alibaba.com>
>>>> ---
>>>> .../hwtracing/coresight/coresight-tmc-core.c | 103 ++++++++++++++----
>>>> drivers/hwtracing/coresight/coresight-tmc.h | 11 +-
>>>> 2 files changed, 91 insertions(+), 23 deletions(-)
>>>>
>>>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
>>>> index d0276af82494..0977f1ce6338 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
>>>> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
>>>> @@ -12,7 +12,6 @@
>>>> #include <linux/io.h>
>>>> #include <linux/err.h>
>>>> #include <linux/fs.h>
>>>> -#include <linux/miscdevice.h>
>>>> #include <linux/mutex.h>
>>>> #include <linux/property.h>
>>>> #include <linux/uaccess.h>
>>>> @@ -31,6 +30,12 @@ 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;
>>>> @@ -146,8 +151,10 @@ static int tmc_read_unprepare(struct tmc_drvdata *drvdata)
>>>> 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_cdev *cdev = container_of(inode->i_cdev,
>>>> + struct tmc_cdev, cdev);
>>>> + struct tmc_drvdata *drvdata = container_of(cdev,
>>>> + struct tmc_drvdata, cdev);
>>>>
>>>> ret = tmc_read_prepare(drvdata);
>>>> if (ret)
>>>> @@ -178,8 +185,10 @@ 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_cdev *cdev = container_of(file->f_inode->i_cdev,
>>>> + struct tmc_cdev, cdev);
>>>> + struct tmc_drvdata *drvdata = container_of(cdev,
>>>> + struct tmc_drvdata, cdev);
>>>> actual = tmc_get_sysfs_trace(drvdata, *ppos, len, &bufp);
>>>> if (actual <= 0)
>>>> return 0;
>>>> @@ -199,8 +208,10 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
>>>> 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_cdev *cdev = container_of(inode->i_cdev,
>>>> + struct tmc_cdev, cdev);
>>>> + struct tmc_drvdata *drvdata = container_of(cdev,
>>>> + struct tmc_drvdata, cdev);
>>>>
>>>> ret = tmc_read_unprepare(drvdata);
>>>> if (ret)
>>>> @@ -451,6 +462,7 @@ 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 +558,32 @@ 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 +613,11 @@ 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, MINOR(dev->devt));
>>>> + device_destroy(tmc_class, dev->devt);
>>>> + cdev_del(&drvdata->cdev.cdev);
>>>> coresight_unregister(drvdata->csdev);
>>>> }
>>>>
>>>> @@ -618,7 +646,42 @@ 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");
>>>> + unregister_chrdev_region(tmc_major, TMC_DEV_MAX);
>>>> + return PTR_ERR(tmc_class);
>>>> + }
>>>> +
>>>> + 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 <pratikp at codeaurora.org>");
>>>> 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..11441c6b9c26 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-tmc.h
>>>> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
>>>> @@ -7,9 +7,9 @@
>>>> #ifndef _CORESIGHT_TMC_H
>>>> #define _CORESIGHT_TMC_H
>>>>
>>>> +#include <linux/cdev.h>
>>>> #include <linux/dma-mapping.h>
>>>> #include <linux/idr.h>
>>>> -#include <linux/miscdevice.h>
>>>> #include <linux/mutex.h>
>>>> #include <linux/refcount.h>
>>>>
>>>> @@ -163,11 +163,16 @@ 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 +196,7 @@ 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
>>>>
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