Re: [RESEND PATCH v2] coresight: change tmc from misc device to cdev device

On Thu, 13 Jan 2022 at 20:16, Jiankang Chen jkchen@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@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 On January 5th you posted a new version with a simple "PATCH" tag which, minutes later, was superseded by another patch labelled "RESEND PATCH".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.

sorry

jay

...

...

Signed-off-by: Jay Chen jkchen@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@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