From: Mika Penttilä <mpenttil@xxxxxxxxxx>
HMM selftests use an in-kernel pseudo device to emulate device private
memory. The pseudo device registers a major device range for two 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.
This duplicates a fair amount of boilerplate that misc device can do
instead.
Change this to use misc device, which makes the device node names appear
for us. This also enables udev-like processing if desired.
Delete the /proc/devices parsing from the user-space test script, now
that it is unnecessary.
Signed-off-by: Mika Penttilä <mpenttil@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
---
v3:
- use cdev_device_add() instead of miscdevice
v2:
- Cleanups per review comments from John Hubbard
- Added Tested-by and Ccs
lib/test_hmm.c | 25 ++++++++++++++++++-------
tools/testing/selftests/vm/test_hmm.sh | 6 ------
2 files changed, 18 insertions(+), 13 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 767538089a62..d247e9c0fe94 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -29,11 +29,17 @@
#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;
@@ -74,7 +80,7 @@ struct dmirror {
* ZONE_DEVICE pages for migration and simulating device memory.
*/
struct dmirror_chunk {
- struct dev_pagemap pagemap;
+ struct dev_pagemap pagemap;
struct dmirror_device *mdevice;
};
@@ -82,8 +88,9 @@ struct dmirror_chunk {
* Per device data.
*/
struct dmirror_device {
- struct cdev cdevice;
- struct hmm_devmem *devmem;
+ struct cdev cdevice;
+ struct device device;
+ struct hmm_devmem *devmem;
unsigned int devmem_capacity;
unsigned int devmem_count;
@@ -132,7 +139,7 @@ static int dmirror_fops_open(struct inode *inode, struct file *filp)
xa_init(&dmirror->pt);
ret = mmu_interval_notifier_insert(&dmirror->notifier, current->mm,
- 0, ULONG_MAX & PAGE_MASK, &dmirror_min_ops);
+ 0, ULONG_MAX & PAGE_MASK, &dmirror_min_ops);
if (ret) {
kfree(dmirror);
return ret;
@@ -1225,7 +1232,11 @@ 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);
+ dev_set_name(&mdevice->device, "%s", dmirror_device_names[id]);
+ mdevice->device.devt = dev;
+
+ ret = cdev_device_add(&mdevice->cdevice, &mdevice->device);
if (ret)
return ret;
@@ -1252,7 +1263,7 @@ 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)
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()
