Commit 6a760f58 authored by Mika Penttilä's avatar Mika Penttilä Committed by Andrew Morton
Browse files

mm/hmm/test: use char dev with struct device to get device node 

HMM selftests use an in-kernel pseudo device to emulate device memory. 
The pseudo device registers a major device range for two or four pseudo
device instances.  User space has a script that reads /proc/devices in
order to find the assigned major number, and sends that to mknod(1), once
for each node.

Change this to properly use cdev and struct device APIs.

Delete the /proc/devices parsing from the user-space test script, now that
it is unnecessary.

Also, delete an unused field in struct dmirror_device: devmem.

Link: https://lkml.kernel.org/r/20220826050631.25771-1-mpenttil@redhat.com


Signed-off-by: default avatarMika Penttilä <mpenttil@redhat.com>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent dcc57966

lib/test_hmm.c

+10 −3
Original line number Diff line number Diff line
@@ -107,8 +107,8 @@ struct dmirror_chunk { 
 */

struct dmirror_device {

	struct cdev		cdevice;

	struct hmm_devmem	*devmem;

	unsigned int            zone_device_type;

	struct device		device;



	unsigned int		devmem_capacity;

	unsigned int		devmem_count;
@@ -1390,7 +1390,14 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) 


	cdev_init(&mdevice->cdevice, &dmirror_fops);

	mdevice->cdevice.owner = THIS_MODULE;

	ret = cdev_add(&mdevice->cdevice, dev, 1);

	device_initialize(&mdevice->device);

	mdevice->device.devt = dev;



	ret = dev_set_name(&mdevice->device, "hmm_dmirror%u", id);

	if (ret)

		return ret;



	ret = cdev_device_add(&mdevice->cdevice, &mdevice->device);

	if (ret)

		return ret;
@@ -1416,7 +1423,7 @@ static void dmirror_device_remove(struct dmirror_device *mdevice) 
		kfree(mdevice->devmem_chunks);

	}



	cdev_del(&mdevice->cdevice);

	cdev_device_del(&mdevice->cdevice, &mdevice->device);

}



static int __init hmm_dmirror_init(void)

tools/testing/selftests/vm/test_hmm.sh

+0 −10
Original line number Diff line number Diff line
@@ -52,21 +52,11 @@ load_driver() 
			usage

		fi

	fi

	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

		if [ $# -eq 2 ]; then

			mknod /dev/hmm_dmirror2 c $major 2

			mknod /dev/hmm_dmirror3 c $major 3

		fi

	fi

}



unload_driver()

{

	modprobe -r $DRIVER > /dev/null 2>&1

	rm -f /dev/hmm_dmirror?

}



run_smoke()