dmaengine: idxd: Make max batch size attributes in sysfs invisible for Intel IAA

mainline inclusion
from mainline-v6.2
commit 91123b37
category: bugfix
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596WO
CVE: NA

Intel-SIG: commit 91123b37 dmaengine: idxd: Make max batch size attributes in sysfs invisible for Intel IAA.
Incremental backporting patches for DSA/IAA on Intel Xeon platform.

--------------------------------

In current code, dev.max_batch_size and wq.max_batch_size attributes in
sysfs are exposed to user to show or update the values.

>From Intel IAA spec [1], Intel IAA does not support batch processing. So
these sysfs attributes should not be supported on IAA device.

Fix this issue by making the attributes of max_batch_size invisible in
sysfs through is_visible() filter when the device is IAA.

Add description in the ABI documentation to mention that the attributes
are not visible when the device does not support batch.

[1]: https://cdrdv2.intel.com/v1/dl/getContent/721858



Fixes: e7184b15 ("dmaengine: idxd: add support for configurable max wq batch size")
Fixes: c52ca478 ("dmaengine: idxd: add configuration component of driver")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220930201528.18621-3-xiaochen.shen@intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>