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[91.145.109.188]) by smtp.gmail.com with ESMTPSA id m8-20020a05651202e800b0044a2d45534fsm161250lfq.103.2022.03.20.19.45.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 20 Mar 2022 19:45:00 -0700 (PDT) From: mpenttil@redhat.com To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: apopple@nvidia.com, jhubbard@nvidia.com, rcampbell@nvidia.com, jgg@ziepe.ca, vbabka@suse.cz, =?UTF-8?q?Mika=20Penttil=C3=A4?= Subject: [PATCH v3] mm/hmm/test: use char dev with struct device to get device node Date: Mon, 21 Mar 2022 04:44:00 +0200 Message-Id: <20220321024400.20956-1-mpenttil@redhat.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mika Penttil=C3=A4 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 Penttil=C3=A4 Cc: Alistair Popple Cc: John Hubbard Cc: Ralph Campbell Cc: Jason Gunthorpe Cc: Vlastimil Babka --- 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 @@ =20 #include "test_hmm_uapi.h" =20 -#define DMIRROR_NDEVICES 2 #define DMIRROR_RANGE_FAULT_TIMEOUT 1000 #define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U) #define DEVMEM_CHUNKS_RESERVE 16 =20 +static const char *dmirror_device_names[] =3D { + "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; }; =20 @@ -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; =20 unsigned int devmem_capacity; unsigned int devmem_count; @@ -132,7 +139,7 @@ static int dmirror_fops_open(struct inode *inode, struc= t file *filp) xa_init(&dmirror->pt); =20 ret =3D 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) =20 cdev_init(&mdevice->cdevice, &dmirror_fops); mdevice->cdevice.owner =3D THIS_MODULE; - ret =3D cdev_add(&mdevice->cdevice, dev, 1); + device_initialize(&mdevice->device); + dev_set_name(&mdevice->device, "%s", dmirror_device_names[id]); + mdevice->device.devt =3D dev; + + ret =3D cdev_device_add(&mdevice->cdevice, &mdevice->device); if (ret) return ret; =20 @@ -1252,7 +1263,7 @@ static void dmirror_device_remove(struct dmirror_devi= ce *mdevice) kfree(mdevice->devmem_chunks); } =20 - cdev_del(&mdevice->cdevice); + cdev_device_del(&mdevice->cdevice, &mdevice->device); } =20 static int __init hmm_dmirror_init(void) diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftes= ts/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 [ $? =3D=3D 0 ]; then - major=3D$(awk "\$2=3D=3D\"HMM_DMIRROR\" {print \$1}" /proc/devices) - mknod /dev/hmm_dmirror0 c $major 0 - mknod /dev/hmm_dmirror1 c $major 1 - fi } =20 unload_driver() { modprobe -r $DRIVER > /dev/null 2>&1 - rm -f /dev/hmm_dmirror? } =20 run_smoke() --=20 2.17.1