diff options
| author | Stanislav Kinsburskii <skinsburskii@gmail.com> | 2026-06-29 16:30:14 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-07-20 17:41:26 -0700 |
| commit | 4fc089235378d1f9ddb6bcbe67c192ffdcaae0ed (patch) | |
| tree | 512b3ee67aac02da57d80a7a447d6b046114a7cd | |
| parent | ea3034b2b00fa50c8d2518d0804c9d427bbafa86 (diff) | |
lib: test_hmm: use device devt for coherent device range selection
Commit af69016dab96 ("lib: test_hmm: implement a device release method")
moved the initial dmirror_allocate_chunk() call before cdev_device_add().
That means the struct cdev has not been added yet, so cdev_add() has not
initialized mdevice->cdevice.dev.
The coherent-device range selection uses the device minor to choose
between spm_addr_dev0 and spm_addr_dev1. Reading
MINOR(mdevice->cdevice.dev) before cdev_add() therefore always sees an
uninitialized dev_t. As a result, both coherent devices select the same
physical range, and adding the second device fails due to the overlapping
dev_pagemap range.
Use mdevice->device.devt instead. It is initialized in
dmirror_device_init() before dmirror_allocate_chunk() is called and is the
same dev_t later passed to cdev_device_add().
Link: https://lore.kernel.org/178277581197.172200.16265155329935822153.stgit@skinsburskii
Fixes: af69016dab96 ("lib: test_hmm: implement a device release method")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | lib/test_hmm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 9c59d1ceb5b5..c4adbf98fac7 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -581,7 +581,7 @@ static int dmirror_allocate_chunk(struct dmirror_device *mdevice, devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; break; case HMM_DMIRROR_MEMORY_DEVICE_COHERENT: - devmem->pagemap.range.start = (MINOR(mdevice->cdevice.dev) - 2) ? + devmem->pagemap.range.start = (MINOR(mdevice->device.devt) - 2) ? spm_addr_dev0 : spm_addr_dev1; devmem->pagemap.range.end = devmem->pagemap.range.start + |