dmaengine: idxd: make idxd_wq_enable() return 0 if wq is already enabled

mainline inclusion
from mainline-v5.19
commit d1a28597
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596WO


CVE: NA

Intel-SIG: commit d1a28597 dmaengine: idxd: make idxd_wq_enable() return 0 if wq is already enabled.
Incremental backporting patches for DSA/IAA on Intel Xeon platform.

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When calling idxd_wq_enable() and wq is already enabled, code should return 0
and indicate function is successful instead of return error code and fail.
This should also put idxd_wq_enable() in sync with idxd_wq_disable() where
it returns 0 if wq is already disabled.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/165090980906.1378449.1939401700832432886.stgit@djiang5-desk3.ch.intel.com


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