wifi: ath12k: Add support for handling incumbent signal interference in 6 GHz

wifi: ath12k: Add support for handling incumbent signal interference in 6 GHz

When incumbent signal interference is detected by an AP/mesh interface
operating in the 6 GHz band, as mandated by the FCC, it is expected to
vacate the affected channels. The firmware indicates the interference to
the host using the WMI_DCS_INTERFERENCE_EVENT.

To handle the new WMI event, first parse it to retrieve the interference
information. Next, validate the interference-detected channel and
the interference bitmap. The interference bitmap received from the
firmware uses a mapping where bit 0 corresponds to the primary
20 MHz segment, regardless of its position within the operating
bandwidth. Bit 1 represents the next adjacent 20 MHz segment, bit 2
the lower 20 MHz segment of the adjacent 40 MHz segment, and so
on, progressing sequentially across the bandwidth. However, for userspace
consumption via mac80211, this bitmap must be transformed into a
standardized format such that each bit position directly maps to the
corresponding sub-channel index within the operating bandwidth.
Finally, indicate the transformed interference bitmap to mac80211, which
then notifies userspace of the interference. Once the incumbent signal
interference is detected, firmware suspends TX internally on the affected
operating channel while userspace decides the mitigation action. Userspace
is expected to trigger a channel switch or bandwidth reduction to mitigate
the interference. Also, add a flag handling_in_progress to indicate that
handling of interference is in progress. Set it to true after
indicating to mac80211 about the interference. Reset the flag to false
after the operating channel is switched by userspace. This prevents
processing any further interference events when there is already a
previous event being handled. Hence, further events are processed only
after a channel switch request is received from userspace for the
previous event.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.5-01651-QCAHKSWPL_SILICONZ-1

Signed-off-by: Aishwarya R <aishwarya.r@oss.qualcomm.com>
Co-developed-by: Hari Chandrakanthan <quic_haric@quicinc.com>
Signed-off-by: Hari Chandrakanthan <quic_haric@quicinc.com>
Signed-off-by: Amith A <amith.a@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Link: https://patch.msgid.link/20260511040242.1351792-2-amith.a@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>