| Message ID | 20211201070942.24947-1-jkchen@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC] Change coresight tmc from misc device to cdev device | expand |
Hi Jay, On Wed, Dec 01, 2021 at 03:09:42PM +0800, Jay Chen wrote: > For coresight in the server scenario, if there are too many > cpu cores and too many tmc peripherals, the error of insufficient > device numbers will occur by misc device > There really is more than 128 miscdevice allocated in your system? How may TMC do you have? > Signed-off-by: Jay Chen <jkchen@linux.alibaba.com> > --- > drivers/hwtracing/coresight/coresight-core.c | 53 +++++++++++++++++++ > .../hwtracing/coresight/coresight-tmc-core.c | 13 ++--- > drivers/hwtracing/coresight/coresight-tmc.h | 4 +- > include/linux/coresight.h | 23 ++++++++ > 4 files changed, 83 insertions(+), 10 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c > index 8a18c71df37a..b0cca3060f4e 100644 > --- a/drivers/hwtracing/coresight/coresight-core.c > +++ b/drivers/hwtracing/coresight/coresight-core.c > @@ -17,6 +17,7 @@ > #include <linux/coresight.h> > #include <linux/of_platform.h> > #include <linux/delay.h> > +#include <linux/cdev.h> > #include <linux/pm_runtime.h> > > #include "coresight-etm-perf.h" > @@ -1567,6 +1568,58 @@ void coresight_release_platform_data(struct coresight_device *csdev, > coresight_remove_conns_sysfs_group(csdev); > } > > +int coresight_cdev_register(struct coresight_cdev *cdev, const struct file_operations *fops, > + const char *name) > +{ > + struct device *device; > + > + if (alloc_chrdev_region(&cdev->devno, 0, 1, name)) { > + pr_err("failed to create the coresight cdev region\n"); > + return -EFAULT; > + } > + > + cdev->class = class_create(THIS_MODULE, name); > + if (IS_ERR(cdev->class)) { > + pr_err("failed to create the coresight class\n"); > + goto coresight_unregister_region; > + } From the above a new class is created for every TMC, even if they are all the same. A better way to do this would be to create a single TMC class with a new cdev for every new TMC. To do this alloc_chrdev_region() and class_create() have to be called when the module is added to the system. Have a look at funnel_init() on how to refactor the TMC core driver with an init function and rpmsg_chrdev_init() for the chrdev region allocation and the class creation. From there every time a TMC is probe cdev_init() and cdev_add() can be called - look at rpmsg_chrdev_probe() for an example. Instead of using an IDA to pick out a minor number you should be able to use dev_list->nr_idx - 1. Thanks, Mathieu > + > + cdev_init(&cdev->cdev, fops); > + if (cdev_add(&cdev->cdev, cdev->devno, 1)) { > + pr_err("failed to add the coresight cdev\n"); > + goto coresight_free_class; > + } > + > + device = device_create(cdev->class, NULL, cdev->devno, > + cdev, name); > + if (IS_ERR(device)) { > + pr_err("failed to create device for coresight\n"); > + goto coresight_del_cdev; > + } > + > + return 0; > + > +coresight_del_cdev: > + cdev_del(&cdev->cdev); > +coresight_free_class: > + class_destroy(cdev->class); > +coresight_unregister_region: > + unregister_chrdev_region(cdev->devno, 1); > + > + return -EFAULT; > +} > +EXPORT_SYMBOL_GPL(coresight_cdev_register); > + > +int coresight_cdev_unregister(struct coresight_cdev *cdev) > +{ > + device_destroy(cdev->class, cdev->devno); > + cdev_del(&cdev->cdev); > + class_destroy(cdev->class); > + unregister_chrdev_region(cdev->devno, 1); > + return 0; > +} > +EXPORT_SYMBOL_GPL(coresight_cdev_unregister); > + > struct coresight_device *coresight_register(struct coresight_desc *desc) > { > int ret; > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index 74c6323d4d6a..c4aae8ff65eb 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -147,7 +147,7 @@ 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 +179,7 @@ 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 +200,7 @@ 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) > @@ -529,10 +529,7 @@ 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 = coresight_cdev_register(&drvdata->cdev, &tmc_fops, desc.name); > if (ret) > coresight_unregister(drvdata->csdev); > else > @@ -572,7 +569,7 @@ static void tmc_remove(struct amba_device *adev) > * etb fops in this case, device is there until last file > * handler to this device is closed. > */ > - misc_deregister(&drvdata->miscdev); > + coresight_cdev_unregister(&drvdata->cdev); > coresight_unregister(drvdata->csdev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index b91ec7dde7bc..c37e2ed1cb9d 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -166,7 +166,7 @@ struct etr_buf { > * 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. > + * @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. > @@ -188,7 +188,7 @@ struct etr_buf { > struct tmc_drvdata { > void __iomem *base; > struct coresight_device *csdev; > - struct miscdevice miscdev; > + struct coresight_cdev cdev; > spinlock_t spinlock; > pid_t pid; > bool reading; > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > index 93a2922b7653..aebe8b8327ad 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -9,6 +9,7 @@ > #include <linux/device.h> > #include <linux/io.h> > #include <linux/perf_event.h> > +#include <linux/cdev.h> > #include <linux/sched.h> > > /* Peripheral id registers (0xFD0-0xFEC) */ > @@ -252,6 +253,12 @@ struct coresight_device { > void *active_cscfg_ctxt; > }; > > +struct coresight_cdev { > + dev_t devno; > + struct class *class; > + struct cdev cdev; > +}; > + > /* > * coresight_dev_list - Mapping for devices to "name" index for device > * names. > @@ -506,6 +513,10 @@ void coresight_relaxed_write64(struct coresight_device *csdev, > u64 val, u32 offset); > void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset); > > +int coresight_cdev_register(struct coresight_cdev *cdev, const struct file_operations *fops, > + const char *name); > + > +int coresight_cdev_unregister(struct coresight_cdev *cdev); > #else > static inline struct coresight_device * > coresight_register(struct coresight_desc *desc) { return NULL; } > @@ -581,6 +592,18 @@ static inline void coresight_write64(struct coresight_device *csdev, u64 val, u3 > { > } > > +static inline int coresight_cdev_register(struct coresight_cdev *cdev, > + const struct file_operations *fops, > + const char *name) > +{ > + return 0; > +} > + > +static inline int coresight_cdev_unregister(struct coresight_cdev *cdev) > +{ > + return 0; > +} > + > #endif /* IS_ENABLED(CONFIG_CORESIGHT) */ > > extern int coresight_get_cpu(struct device *dev); > -- > 2.27.0 >
Hi Mathieu Thank you for your reply，firstly. 在 2021/12/10 02:03, Mathieu Poirier 写道: > Hi Jay, > > On Wed, Dec 01, 2021 at 03:09:42PM +0800, Jay Chen wrote: >> For coresight in the server scenario, if there are too many >> cpu cores and too many tmc peripherals, the error of insufficient >> device numbers will occur by misc device >> > There really is more than 128 miscdevice allocated in your system? How may TMC > do you have? There are 128 TMCs on our system. > >> Signed-off-by: Jay Chen <jkchen@linux.alibaba.com> >> --- >> drivers/hwtracing/coresight/coresight-core.c | 53 +++++++++++++++++++ >> .../hwtracing/coresight/coresight-tmc-core.c | 13 ++--- >> drivers/hwtracing/coresight/coresight-tmc.h | 4 +- >> include/linux/coresight.h | 23 ++++++++ >> 4 files changed, 83 insertions(+), 10 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c >> index 8a18c71df37a..b0cca3060f4e 100644 >> --- a/drivers/hwtracing/coresight/coresight-core.c >> +++ b/drivers/hwtracing/coresight/coresight-core.c >> @@ -17,6 +17,7 @@ >> #include <linux/coresight.h> >> #include <linux/of_platform.h> >> #include <linux/delay.h> >> +#include <linux/cdev.h> >> #include <linux/pm_runtime.h> >> >> #include "coresight-etm-perf.h" >> @@ -1567,6 +1568,58 @@ void coresight_release_platform_data(struct coresight_device *csdev, >> coresight_remove_conns_sysfs_group(csdev); >> } >> >> +int coresight_cdev_register(struct coresight_cdev *cdev, const struct file_operations *fops, >> + const char *name) >> +{ >> + struct device *device; >> + >> + if (alloc_chrdev_region(&cdev->devno, 0, 1, name)) { >> + pr_err("failed to create the coresight cdev region\n"); >> + return -EFAULT; >> + } >> + >> + cdev->class = class_create(THIS_MODULE, name); >> + if (IS_ERR(cdev->class)) { >> + pr_err("failed to create the coresight class\n"); >> + goto coresight_unregister_region; >> + } > From the above a new class is created for every TMC, even if they are all the > same. A better way to do this would be to create a single TMC class with a new > cdev for every new TMC. > > To do this alloc_chrdev_region() and class_create() have to be called when the > module is added to the system. Have a look at funnel_init() on how to refactor > the TMC core driver with an init function and rpmsg_chrdev_init() for the chrdev > region allocation and the class creation. > > From there every time a TMC is probe cdev_init() and cdev_add() can be called - > look at rpmsg_chrdev_probe() for an example. Instead of using an IDA to pick out > a minor number you should be able to use dev_list->nr_idx - 1. > > Thanks, > Mathieu Thank you for your suggestion. I will revise it and send another patch >> + >> + cdev_init(&cdev->cdev, fops); >> + if (cdev_add(&cdev->cdev, cdev->devno, 1)) { >> + pr_err("failed to add the coresight cdev\n"); >> + goto coresight_free_class; >> + } >> + >> + device = device_create(cdev->class, NULL, cdev->devno, >> + cdev, name); >> + if (IS_ERR(device)) { >> + pr_err("failed to create device for coresight\n"); >> + goto coresight_del_cdev; >> + } >> + >> + return 0; >> + >> +coresight_del_cdev: >> + cdev_del(&cdev->cdev); >> +coresight_free_class: >> + class_destroy(cdev->class); >> +coresight_unregister_region: >> + unregister_chrdev_region(cdev->devno, 1); >> + >> + return -EFAULT; >> +} >> +EXPORT_SYMBOL_GPL(coresight_cdev_register); >> + >> +int coresight_cdev_unregister(struct coresight_cdev *cdev) >> +{ >> + device_destroy(cdev->class, cdev->devno); >> + cdev_del(&cdev->cdev); >> + class_destroy(cdev->class); >> + unregister_chrdev_region(cdev->devno, 1); >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(coresight_cdev_unregister); >> + >> struct coresight_device *coresight_register(struct coresight_desc *desc) >> { >> int ret; >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c >> index 74c6323d4d6a..c4aae8ff65eb 100644 >> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c >> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c >> @@ -147,7 +147,7 @@ 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 +179,7 @@ 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 +200,7 @@ 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) >> @@ -529,10 +529,7 @@ 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 = coresight_cdev_register(&drvdata->cdev, &tmc_fops, desc.name); >> if (ret) >> coresight_unregister(drvdata->csdev); >> else >> @@ -572,7 +569,7 @@ static void tmc_remove(struct amba_device *adev) >> * etb fops in this case, device is there until last file >> * handler to this device is closed. >> */ >> - misc_deregister(&drvdata->miscdev); >> + coresight_cdev_unregister(&drvdata->cdev); >> coresight_unregister(drvdata->csdev); >> } >> >> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h >> index b91ec7dde7bc..c37e2ed1cb9d 100644 >> --- a/drivers/hwtracing/coresight/coresight-tmc.h >> +++ b/drivers/hwtracing/coresight/coresight-tmc.h >> @@ -166,7 +166,7 @@ struct etr_buf { >> * 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. >> + * @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. >> @@ -188,7 +188,7 @@ struct etr_buf { >> struct tmc_drvdata { >> void __iomem *base; >> struct coresight_device *csdev; >> - struct miscdevice miscdev; >> + struct coresight_cdev cdev; >> spinlock_t spinlock; >> pid_t pid; >> bool reading; >> diff --git a/include/linux/coresight.h b/include/linux/coresight.h >> index 93a2922b7653..aebe8b8327ad 100644 >> --- a/include/linux/coresight.h >> +++ b/include/linux/coresight.h >> @@ -9,6 +9,7 @@ >> #include <linux/device.h> >> #include <linux/io.h> >> #include <linux/perf_event.h> >> +#include <linux/cdev.h> >> #include <linux/sched.h> >> >> /* Peripheral id registers (0xFD0-0xFEC) */ >> @@ -252,6 +253,12 @@ struct coresight_device { >> void *active_cscfg_ctxt; >> }; >> >> +struct coresight_cdev { >> + dev_t devno; >> + struct class *class; >> + struct cdev cdev; >> +}; >> + >> /* >> * coresight_dev_list - Mapping for devices to "name" index for device >> * names. >> @@ -506,6 +513,10 @@ void coresight_relaxed_write64(struct coresight_device *csdev, >> u64 val, u32 offset); >> void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset); >> >> +int coresight_cdev_register(struct coresight_cdev *cdev, const struct file_operations *fops, >> + const char *name); >> + >> +int coresight_cdev_unregister(struct coresight_cdev *cdev); >> #else >> static inline struct coresight_device * >> coresight_register(struct coresight_desc *desc) { return NULL; } >> @@ -581,6 +592,18 @@ static inline void coresight_write64(struct coresight_device *csdev, u64 val, u3 >> { >> } >> >> +static inline int coresight_cdev_register(struct coresight_cdev *cdev, >> + const struct file_operations *fops, >> + const char *name) >> +{ >> + return 0; >> +} >> + >> +static inline int coresight_cdev_unregister(struct coresight_cdev *cdev) >> +{ >> + return 0; >> +} >> + >> #endif /* IS_ENABLED(CONFIG_CORESIGHT) */ >> >> extern int coresight_get_cpu(struct device *dev); >> -- >> 2.27.0 >>
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 8a18c71df37a..b0cca3060f4e 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -17,6 +17,7 @@ #include <linux/coresight.h> #include <linux/of_platform.h> #include <linux/delay.h> +#include <linux/cdev.h> #include <linux/pm_runtime.h> #include "coresight-etm-perf.h" @@ -1567,6 +1568,58 @@ void coresight_release_platform_data(struct coresight_device *csdev, coresight_remove_conns_sysfs_group(csdev); } +int coresight_cdev_register(struct coresight_cdev *cdev, const struct file_operations *fops, + const char *name) +{ + struct device *device; + + if (alloc_chrdev_region(&cdev->devno, 0, 1, name)) { + pr_err("failed to create the coresight cdev region\n"); + return -EFAULT; + } + + cdev->class = class_create(THIS_MODULE, name); + if (IS_ERR(cdev->class)) { + pr_err("failed to create the coresight class\n"); + goto coresight_unregister_region; + } + + cdev_init(&cdev->cdev, fops); + if (cdev_add(&cdev->cdev, cdev->devno, 1)) { + pr_err("failed to add the coresight cdev\n"); + goto coresight_free_class; + } + + device = device_create(cdev->class, NULL, cdev->devno, + cdev, name); + if (IS_ERR(device)) { + pr_err("failed to create device for coresight\n"); + goto coresight_del_cdev; + } + + return 0; + +coresight_del_cdev: + cdev_del(&cdev->cdev); +coresight_free_class: + class_destroy(cdev->class); +coresight_unregister_region: + unregister_chrdev_region(cdev->devno, 1); + + return -EFAULT; +} +EXPORT_SYMBOL_GPL(coresight_cdev_register); + +int coresight_cdev_unregister(struct coresight_cdev *cdev) +{ + device_destroy(cdev->class, cdev->devno); + cdev_del(&cdev->cdev); + class_destroy(cdev->class); + unregister_chrdev_region(cdev->devno, 1); + return 0; +} +EXPORT_SYMBOL_GPL(coresight_cdev_unregister); + struct coresight_device *coresight_register(struct coresight_desc *desc) { int ret; diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 74c6323d4d6a..c4aae8ff65eb 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -147,7 +147,7 @@ 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 +179,7 @@ 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 +200,7 @@ 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) @@ -529,10 +529,7 @@ 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 = coresight_cdev_register(&drvdata->cdev, &tmc_fops, desc.name); if (ret) coresight_unregister(drvdata->csdev); else @@ -572,7 +569,7 @@ static void tmc_remove(struct amba_device *adev) * etb fops in this case, device is there until last file * handler to this device is closed. */ - misc_deregister(&drvdata->miscdev); + coresight_cdev_unregister(&drvdata->cdev); coresight_unregister(drvdata->csdev); } diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index b91ec7dde7bc..c37e2ed1cb9d 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -166,7 +166,7 @@ struct etr_buf { * 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. + * @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. @@ -188,7 +188,7 @@ struct etr_buf { struct tmc_drvdata { void __iomem *base; struct coresight_device *csdev; - struct miscdevice miscdev; + struct coresight_cdev cdev; spinlock_t spinlock; pid_t pid; bool reading; diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 93a2922b7653..aebe8b8327ad 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -9,6 +9,7 @@ #include <linux/device.h> #include <linux/io.h> #include <linux/perf_event.h> +#include <linux/cdev.h> #include <linux/sched.h> /* Peripheral id registers (0xFD0-0xFEC) */ @@ -252,6 +253,12 @@ struct coresight_device { void *active_cscfg_ctxt; }; +struct coresight_cdev { + dev_t devno; + struct class *class; + struct cdev cdev; +}; + /* * coresight_dev_list - Mapping for devices to "name" index for device * names. @@ -506,6 +513,10 @@ void coresight_relaxed_write64(struct coresight_device *csdev, u64 val, u32 offset); void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset); +int coresight_cdev_register(struct coresight_cdev *cdev, const struct file_operations *fops, + const char *name); + +int coresight_cdev_unregister(struct coresight_cdev *cdev); #else static inline struct coresight_device * coresight_register(struct coresight_desc *desc) { return NULL; } @@ -581,6 +592,18 @@ static inline void coresight_write64(struct coresight_device *csdev, u64 val, u3 { } +static inline int coresight_cdev_register(struct coresight_cdev *cdev, + const struct file_operations *fops, + const char *name) +{ + return 0; +} + +static inline int coresight_cdev_unregister(struct coresight_cdev *cdev) +{ + return 0; +} + #endif /* IS_ENABLED(CONFIG_CORESIGHT) */ extern int coresight_get_cpu(struct device *dev);
For coresight in the server scenario, if there are too many cpu cores and too many tmc peripherals, the error of insufficient device numbers will occur by misc device Signed-off-by: Jay Chen <jkchen@linux.alibaba.com> --- drivers/hwtracing/coresight/coresight-core.c | 53 +++++++++++++++++++ .../hwtracing/coresight/coresight-tmc-core.c | 13 ++--- drivers/hwtracing/coresight/coresight-tmc.h | 4 +- include/linux/coresight.h | 23 ++++++++ 4 files changed, 83 insertions(+), 10 deletions(-)