scsi: ufs: ufshpb: L2P map management for HPB read

scsi: ufs: ufshpb: L2P map management for HPB read

Implement L2P map management in HPB.

The HPB divides logical addresses into several regions. A region consists
of several sub-regions. The sub-region is a basic unit where L2P mapping is
managed. The driver loads L2P mapping data of each sub-region. The loaded
sub-region is called active-state. The HPB driver unloads L2P mapping data
as region unit. The unloaded region is called inactive-state.

Sub-region/region candidates to be loaded and unloaded are delivered from
the UFS device. The UFS device delivers the recommended active sub-region
and inactivate region to the driver using sense data. The HPB module
performs L2P mapping management on the host through the delivered
information.

A pinned region is a preset region on the UFS device that is always
in activate-state.

The data structures for map data requests and L2P mappings use the mempool
API, minimizing allocation overhead while avoiding static allocation.

The mininum size of the memory pool used in the HPB is implemented
as a module parameter so that it can be configurable by the user.

To guarantee a minimum memory pool size of 4MB: ufshpb_host_map_kbytes=4096.

The map_work manages active/inactive via 2 "to-do" lists:

 - hpb->lh_inact_rgn: regions to be inactivated
 - hpb->lh_act_srgn: subregions to be activated

These lists are maintained on I/O completion.

[mkp: switch to REQ_OP_DRV_*]

Link: https://lore.kernel.org/r/20210712085859epcms2p36e420f19564f6cd0c4a45d54949619eb@epcms2p3
Tested-by: Bean Huo <beanhuo@micron.com>
Tested-by: Can Guo <cang@codeaurora.org>
Tested-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Acked-by: Avri Altman <Avri.Altman@wdc.com>
Signed-off-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>