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

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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: Mika Penttilä <mpenttil@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason 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: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Mika Penttilä 2022-08-26 08:06:31 +03:00 committed by Andrew Morton
parent dcc579663f
commit 6a760f58c7
2 changed files with 10 additions and 13 deletions
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13
lib/test_hmm.c
View File

@ -107,8 +107,8 @@ struct dmirror_chunk {
*/ */
struct dmirror_device { struct dmirror_device {
struct cdev cdevice; struct cdev cdevice;
struct hmm_devmem *devmem;
unsigned int zone_device_type; unsigned int zone_device_type;
struct device device;
unsigned int devmem_capacity; unsigned int devmem_capacity;
unsigned int devmem_count; 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); cdev_init(&mdevice->cdevice, &dmirror_fops);
mdevice->cdevice.owner = THIS_MODULE; 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) if (ret)
return ret; return ret;
@ -1416,7 +1423,7 @@ static void dmirror_device_remove(struct dmirror_device *mdevice)
kfree(mdevice->devmem_chunks); kfree(mdevice->devmem_chunks);
} }
cdev_del(&mdevice->cdevice); cdev_device_del(&mdevice->cdevice, &mdevice->device);
} }
static int __init hmm_dmirror_init(void) static int __init hmm_dmirror_init(void)

10
tools/testing/selftests/vm/test_hmm.sh
View File

@ -52,21 +52,11 @@ load_driver()
usage usage
fi fi
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() unload_driver()
{ {
modprobe -r $DRIVER > /dev/null 2>&1 modprobe -r $DRIVER > /dev/null 2>&1
rm -f /dev/hmm_dmirror?
} }
run_smoke() run_smoke()