From: Mika Penttilä <mpenttil@xxxxxxxxxx> HMM selftests use a in-kernel pseudo device to emulate device private memory. For now, the pseudo device registers a major device range for two pseudo device instances. User space has a script that goes figures out from /proc/devices the assigned major and mknods the device nodes. Change this use to a more standard device framework, like misc device, which makes the device node names to appear right under any decent user space. This also makes it possible for udev- like processing if wanted, and the /proc/devices parsing is not needed any more. Signed-off-by: Mika Penttilä <mpenttil@xxxxxxxxxx> --- lib/test_hmm.c | 46 +++++++++++++++----------- tools/testing/selftests/vm/test_hmm.sh | 6 ---- 2 files changed, 26 insertions(+), 26 deletions(-) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 767538089a62..76f6129e1f1f 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -10,7 +10,6 @@ #include <linux/mm.h> #include <linux/module.h> #include <linux/kernel.h> -#include <linux/cdev.h> #include <linux/device.h> #include <linux/mutex.h> #include <linux/rwsem.h> @@ -25,18 +24,25 @@ #include <linux/swapops.h> #include <linux/sched/mm.h> #include <linux/platform_device.h> +#include <linux/miscdevice.h> #include <linux/rmap.h> #include "test_hmm_uapi.h" -#define DMIRROR_NDEVICES 2 #define DMIRROR_RANGE_FAULT_TIMEOUT 1000 #define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U) #define DEVMEM_CHUNKS_RESERVE 16 + +static const char *dmirror_device_names[] = { + "hmm_dmirror0", + "hmm_dmirror1" +}; + +#define DMIRROR_NDEVICES ARRAY_SIZE(dmirror_device_names) + static const struct dev_pagemap_ops dmirror_devmem_ops; static const struct mmu_interval_notifier_ops dmirror_min_ops; -static dev_t dmirror_dev; struct dmirror_device; @@ -82,7 +88,7 @@ struct dmirror_chunk { * Per device data. */ struct dmirror_device { - struct cdev cdevice; + struct miscdevice miscdevice; struct hmm_devmem *devmem; unsigned int devmem_capacity; @@ -118,16 +124,20 @@ static void dmirror_bounce_fini(struct dmirror_bounce *bounce) static int dmirror_fops_open(struct inode *inode, struct file *filp) { - struct cdev *cdev = inode->i_cdev; + + struct dmirror_device *dd = container_of(filp->private_data, + struct dmirror_device, miscdevice + ); struct dmirror *dmirror; int ret; + /* Mirror this process address space */ dmirror = kzalloc(sizeof(*dmirror), GFP_KERNEL); if (dmirror == NULL) return -ENOMEM; - dmirror->mdevice = container_of(cdev, struct dmirror_device, cdevice); + dmirror->mdevice = dd; mutex_init(&dmirror->mutex); xa_init(&dmirror->pt); @@ -1216,16 +1226,18 @@ static const struct dev_pagemap_ops dmirror_devmem_ops = { static int dmirror_device_init(struct dmirror_device *mdevice, int id) { - dev_t dev; + int ret; - dev = MKDEV(MAJOR(dmirror_dev), id); mutex_init(&mdevice->devmem_lock); spin_lock_init(&mdevice->lock); - cdev_init(&mdevice->cdevice, &dmirror_fops); - mdevice->cdevice.owner = THIS_MODULE; - ret = cdev_add(&mdevice->cdevice, dev, 1); + mdevice->miscdevice.minor = MISC_DYNAMIC_MINOR; + mdevice->miscdevice.name = dmirror_device_names[id]; + mdevice->miscdevice.fops = &dmirror_fops; + + ret = misc_register(&mdevice->miscdevice); + if (ret) return ret; @@ -1252,7 +1264,7 @@ static void dmirror_device_remove(struct dmirror_device *mdevice) kfree(mdevice->devmem_chunks); } - cdev_del(&mdevice->cdevice); + misc_deregister(&mdevice->miscdevice); } static int __init hmm_dmirror_init(void) @@ -1260,11 +1272,6 @@ static int __init hmm_dmirror_init(void) int ret; int id; - ret = alloc_chrdev_region(&dmirror_dev, 0, DMIRROR_NDEVICES, - "HMM_DMIRROR"); - if (ret) - goto err_unreg; - for (id = 0; id < DMIRROR_NDEVICES; id++) { ret = dmirror_device_init(dmirror_devices + id, id); if (ret) @@ -1277,8 +1284,7 @@ static int __init hmm_dmirror_init(void) err_chrdev: while (--id >= 0) dmirror_device_remove(dmirror_devices + id); - unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES); -err_unreg: + return ret; } @@ -1288,7 +1294,7 @@ static void __exit hmm_dmirror_exit(void) for (id = 0; id < DMIRROR_NDEVICES; id++) dmirror_device_remove(dmirror_devices + id); - unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES); + } module_init(hmm_dmirror_init); diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh index 0647b525a625..69f5889f8575 100755 --- a/tools/testing/selftests/vm/test_hmm.sh +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -41,17 +41,11 @@ check_test_requirements() load_driver() { modprobe $DRIVER > /dev/null 2>&1 - if [ $? == 0 ]; then - major=$(awk "\$2==\"HMM_DMIRROR\" {print \$1}" /proc/devices) - mknod /dev/hmm_dmirror0 c $major 0 - mknod /dev/hmm_dmirror1 c $major 1 - fi } unload_driver() { modprobe -r $DRIVER > /dev/null 2>&1 - rm -f /dev/hmm_dmirror? } run_smoke() -- 2.17.1