From: =?utf-8?q?Mika_Penttil=C3=A4_=3Cmpenttil=40redhat=2Ecom=3E?=
Date: Fri, 26 Aug 2022 08:06:31 +0300
Subject: mm/hmm/test: use char dev with struct device to get device node
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Git-commit: 6a760f58c792b6f7411f886271bb03f697464433
Patch-mainline: v6.0 or v6.0-rc8 (next release)
References: jsc#PED-1294
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>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
lib/test_hmm.c | 13 ++++++++++---
tools/testing/selftests/vm/test_hmm.sh | 10 ----------
2 files changed, 10 insertions(+), 13 deletions(-)
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -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 dm
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
kfree(mdevice->devmem_chunks);
}
- cdev_del(&mdevice->cdevice);
+ cdev_device_del(&mdevice->cdevice, &mdevice->device);
}
static int __init hmm_dmirror_init(void)
--- a/tools/testing/selftests/vm/test_hmm.sh
+++ b/tools/testing/selftests/vm/test_hmm.sh
@@ -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()