Re: [PATCH v26 2/4] scsi: ufs: L2P map management for HPB read

Can Guo
2021-03-12T01:21:17Z

On 2021-03-03 14:28, Daejun Park wrote:
> This is a patch for managing L2P map in HPB module.
>
> 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 sensedata.
> The HPB module performs L2P mapping management on the host through the
> delivered information.
>
> A pinned region is a pre-set regions on the UFS device that is always
> activate-state.
>
> The data structure for map data request and L2P map uses 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 gurantee a minimum memory pool size of 4MB:
> ufshpb_host_map_kbytes=4096
>
> The map_work manages active/inactive by 2 "to-do" lists.
> Each hpb lun maintains 2 "to-do" lists:
> hpb->lh_inact_rgn - regions to be inactivated, and
> hpb->lh_act_srgn - subregions to be activated
> Those lists are maintained on IO completion.
>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> Reviewed-by: Can Guo <cang@codeaurora.org>
> Acked-by: Avri Altman <Avri.Altman@wdc.com>
> Tested-by: Bean Huo <beanhuo@micron.com>
> Signed-off-by: Daejun Park <daejun7.park@samsung.com>
> ---
> drivers/scsi/ufs/ufs.h | 36 ++
> drivers/scsi/ufs/ufshcd.c | 4 +
> drivers/scsi/ufs/ufshpb.c | 1091 ++++++++++++++++++++++++++++++++++++-
> drivers/scsi/ufs/ufshpb.h | 65 +++
> 4 files changed, 1181 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 65563635e20e..957763db1006 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -472,6 +472,41 @@ struct utp_cmd_rsp {
> u8 sense_data[UFS_SENSE_SIZE];
> };
> ...
> +/*
> + * This function will parse recommended active subregion information
> in sense
> + * data field of response UPIU with SAM_STAT_GOOD state.
> + */
> +void ufshpb_rsp_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
> +{
> + struct ufshpb_lu *hpb = ufshpb_get_hpb_data(lrbp->cmd->device);
> + struct utp_hpb_rsp *rsp_field = &lrbp->ucd_rsp_ptr->hr;
> + int data_seg_len;
> +
> + if (unlikely(lrbp->lun != rsp_field->lun)) {
> + struct scsi_device *sdev;
> + bool found = false;
> +
> + __shost_for_each_device(sdev, hba->host) {
> + hpb = ufshpb_get_hpb_data(sdev);
> +
> + if (!hpb)
> + continue;
> +
> + if (rsp_field->lun == hpb->lun) {
> + found = true;
> + break;
> + }
> + }
> +
> + if (!found)
> + return;
> + }
> +
> + if (!hpb)
> + return;
> +
> + if ((ufshpb_get_state(hpb) != HPB_PRESENT) &&
> + (ufshpb_get_state(hpb) != HPB_SUSPEND)) {
> + dev_notice(&hpb->sdev_ufs_lu->sdev_dev,
> + "%s: ufshpb state is not PRESENT/SUSPEND\n",
> + __func__);

Please mute these prints before hpb is fully initilized, otherwise
there can be tons of these prints during bootup. Say set a flag in
ufshpb_hpb_lu_prepared() and check for that flag - just a rough idea.

Thanks,
Can Guo.

> + return;
> + }
> +