Re: [PATCH v26 2/4] scsi: ufs: L2P map management for HPB read
From: Can Guo
Date: Thu Mar 11 2021 - 21:05:00 EST
On 2021-03-12 09:48, 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@xxxxxxx>
> Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx>
> Acked-by: Avri Altman <Avri.Altman@xxxxxxx>
> Tested-by: Bean Huo <beanhuo@xxxxxxxxxx>
> Signed-off-by: Daejun Park <daejun7.park@xxxxxxxxxxx>
> ---
> 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];
> };
>
> +struct ufshpb_active_field {
> + __be16 active_rgn;
> + __be16 active_srgn;
> +};
> +#define HPB_ACT_FIELD_SIZE 4
> +
> +/**
> + * struct utp_hpb_rsp - Response UPIU structure
> + * @residual_transfer_count: Residual transfer count DW-3
> + * @reserved1: Reserved double words DW-4 to DW-7
> + * @sense_data_len: Sense data length DW-8 U16
> + * @desc_type: Descriptor type of sense data
> + * @additional_len: Additional length of sense data
> + * @hpb_op: HPB operation type
> + * @lun: LUN of response UPIU
> + * @active_rgn_cnt: Active region count
> + * @inactive_rgn_cnt: Inactive region count
> + * @hpb_active_field: Recommended to read HPB region and subregion
> + * @hpb_inactive_field: To be inactivated HPB region and subregion
> + */
> +struct utp_hpb_rsp {
> + __be32 residual_transfer_count;
> + __be32 reserved1[4];
> + __be16 sense_data_len;
> + u8 desc_type;
> + u8 additional_len;
> + u8 hpb_op;
> + u8 lun;
> + u8 active_rgn_cnt;
> + u8 inactive_rgn_cnt;
> + struct ufshpb_active_field hpb_active_field[2];
> + __be16 hpb_inactive_field[2];
> +};
> +#define UTP_HPB_RSP_SIZE 40
> +
> /**
> * struct utp_upiu_rsp - general upiu response structure
> * @header: UPIU header structure DW-0 to DW-2
> @@ -482,6 +517,7 @@ struct utp_upiu_rsp {
> struct utp_upiu_header header;
> union {
> struct utp_cmd_rsp sr;
> + struct utp_hpb_rsp hr;
> struct utp_upiu_query qr;
> };
> };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 49b3d5d24fa6..5852ff44c3cc 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -5021,6 +5021,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba,
> struct ufshcd_lrb *lrbp)
> */
> pm_runtime_get_noresume(hba->dev);
> }
> +
> + if (scsi_status == SAM_STAT_GOOD)
> + ufshpb_rsp_upiu(hba, lrbp);
> break;
> case UPIU_TRANSACTION_REJECT_UPIU:
> /* TODO: handle Reject UPIU Response */
> @@ -9221,6 +9224,7 @@ EXPORT_SYMBOL(ufshcd_shutdown);
> void ufshcd_remove(struct ufs_hba *hba)
> {
> ufs_bsg_remove(hba);
> + ufshpb_remove(hba);
> ufs_sysfs_remove_nodes(hba->dev);
> blk_cleanup_queue(hba->tmf_queue);
> blk_mq_free_tag_set(&hba->tmf_tag_set);
> diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
> index 1a72f6541510..8abadb0e010a 100644
> --- a/drivers/scsi/ufs/ufshpb.c
> +++ b/drivers/scsi/ufs/ufshpb.c
> @@ -16,6 +16,16 @@
> #include "ufshpb.h"
> #include "../sd.h"
>
> +/* memory management */
> +static struct kmem_cache *ufshpb_mctx_cache;
> +static mempool_t *ufshpb_mctx_pool;
> +static mempool_t *ufshpb_page_pool;
> +/* A cache size of 2MB can cache ppn in the 1GB range. */
> +static unsigned int ufshpb_host_map_kbytes = 2048;
> +static int tot_active_srgn_pages;
> +
> +static struct workqueue_struct *ufshpb_wq;
> +
> bool ufshpb_is_allowed(struct ufs_hba *hba)
> {
> return !(hba->ufshpb_dev.hpb_disabled);
> @@ -36,14 +46,892 @@ static void ufshpb_set_state(struct ufshpb_lu
> *hpb, int state)
> atomic_set(&hpb->hpb_state, state);
> }
>
> +static bool ufshpb_is_general_lun(int lun)
> +{
> + return lun < UFS_UPIU_MAX_UNIT_NUM_ID;
> +}
> +
> +static bool
> +ufshpb_is_pinned_region(struct ufshpb_lu *hpb, int rgn_idx)
> +{
> + if (hpb->lu_pinned_end != PINNED_NOT_SET &&
> + rgn_idx >= hpb->lu_pinned_start &&
> + rgn_idx <= hpb->lu_pinned_end)
> + return true;
> +
> + return false;
> +}
> +
> +static void ufshpb_kick_map_work(struct ufshpb_lu *hpb)
> +{
> + bool ret = false;
> + unsigned long flags;
> +
> + if (ufshpb_get_state(hpb) != HPB_PRESENT)
> + return;
> +
> + spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> + if (!list_empty(&hpb->lh_inact_rgn) ||
> !list_empty(&hpb->lh_act_srgn))
> + ret = true;
> + spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> +
> + if (ret)
> + queue_work(ufshpb_wq, &hpb->map_work);
> +}
> +
> +static bool ufshpb_is_hpb_rsp_valid(struct ufs_hba *hba,
> + struct ufshcd_lrb *lrbp,
> + struct utp_hpb_rsp *rsp_field)
> +{
> + /* Check HPB_UPDATE_ALERT */
> + if (!(lrbp->ucd_rsp_ptr->header.dword_2 &
> + UPIU_HEADER_DWORD(0, 2, 0, 0)))
> + return false;
> +
> + if (be16_to_cpu(rsp_field->sense_data_len) != DEV_SENSE_SEG_LEN ||
> + rsp_field->desc_type != DEV_DES_TYPE ||
> + rsp_field->additional_len != DEV_ADDITIONAL_LEN ||
> + rsp_field->active_rgn_cnt > MAX_ACTIVE_NUM ||
> + rsp_field->inactive_rgn_cnt > MAX_INACTIVE_NUM ||
> + rsp_field->hpb_op == HPB_RSP_NONE ||
> + (rsp_field->hpb_op == HPB_RSP_REQ_REGION_UPDATE &&
> + !rsp_field->active_rgn_cnt && !rsp_field->inactive_rgn_cnt))
> + return false;
> +
> + if (!ufshpb_is_general_lun(rsp_field->lun)) {
> + dev_warn(hba->dev, "ufshpb: lun(%d) not supported\n",
> + lrbp->lun);
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
> + struct ufshpb_subregion *srgn)
> +{
> + struct ufshpb_req *map_req;
> + struct request *req;
> + struct bio *bio;
> + int retries = HPB_MAP_REQ_RETRIES;
> +
> + map_req = kmem_cache_alloc(hpb->map_req_cache, GFP_KERNEL);
> + if (!map_req)
> + return NULL;
> +
> +retry:
> + req = blk_get_request(hpb->sdev_ufs_lu->request_queue,
> + REQ_OP_SCSI_IN, BLK_MQ_REQ_NOWAIT);
> +
> + if ((PTR_ERR(req) == -EWOULDBLOCK) && (--retries > 0)) {
> + usleep_range(3000, 3100);
> + goto retry;
> + }
> +
> + if (IS_ERR(req))
> + goto free_map_req;
> +
> + bio = bio_alloc(GFP_KERNEL, hpb->pages_per_srgn);
> + if (!bio) {
> + blk_put_request(req);
> + goto free_map_req;
> + }
> +
> + map_req->hpb = hpb;
> + map_req->req = req;
> + map_req->bio = bio;
> +
> + map_req->rgn_idx = srgn->rgn_idx;
> + map_req->srgn_idx = srgn->srgn_idx;
> + map_req->mctx = srgn->mctx;
> +
> + return map_req;
> +
> +free_map_req:
> + kmem_cache_free(hpb->map_req_cache, map_req);
> + return NULL;
> +}
> +
> +static void ufshpb_put_map_req(struct ufshpb_lu *hpb,
> + struct ufshpb_req *map_req)
> +{
> + bio_put(map_req->bio);
> + blk_put_request(map_req->req);
> + kmem_cache_free(hpb->map_req_cache, map_req);
> +}
> +
> +static int ufshpb_clear_dirty_bitmap(struct ufshpb_lu *hpb,
> + struct ufshpb_subregion *srgn)
> +{
> + u32 num_entries = hpb->entries_per_srgn;
> +
> + if (!srgn->mctx) {
> + dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> + "no mctx in region %d subregion %d.\n",
> + srgn->rgn_idx, srgn->srgn_idx);
> + return -1;
> + }
> +
> + if (unlikely(srgn->is_last))
> + num_entries = hpb->last_srgn_entries;
> +
> + bitmap_zero(srgn->mctx->ppn_dirty, num_entries);
> + return 0;
> +}
> +
> +static void ufshpb_update_active_info(struct ufshpb_lu *hpb, int
> rgn_idx,
> + int srgn_idx)
> +{
> + struct ufshpb_region *rgn;
> + struct ufshpb_subregion *srgn;
> +
> + rgn = hpb->rgn_tbl + rgn_idx;
> + srgn = rgn->srgn_tbl + srgn_idx;
> +
> + list_del_init(&rgn->list_inact_rgn);
> +
> + if (list_empty(&srgn->list_act_srgn))
> + list_add_tail(&srgn->list_act_srgn, &hpb->lh_act_srgn);
> +}
> +
> +static void ufshpb_update_inactive_info(struct ufshpb_lu *hpb, int
> rgn_idx)
> +{
> + struct ufshpb_region *rgn;
> + struct ufshpb_subregion *srgn;
> + int srgn_idx;
> +
> + rgn = hpb->rgn_tbl + rgn_idx;
> +
> + for_each_sub_region(rgn, srgn_idx, srgn)
> + list_del_init(&srgn->list_act_srgn);
> +
> + if (list_empty(&rgn->list_inact_rgn))
> + list_add_tail(&rgn->list_inact_rgn, &hpb->lh_inact_rgn);
> +}
> +
> +static void ufshpb_activate_subregion(struct ufshpb_lu *hpb,
> + struct ufshpb_subregion *srgn)
> +{
> + struct ufshpb_region *rgn;
> +
> + /*
> + * If there is no mctx in subregion
> + * after I/O progress for HPB_READ_BUFFER, the region to which the
> + * subregion belongs was evicted.
> + * Make sure the region must not evict in I/O progress
> + */
> + if (!srgn->mctx) {
> + dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> + "no mctx in region %d subregion %d.\n",
> + srgn->rgn_idx, srgn->srgn_idx);
> + srgn->srgn_state = HPB_SRGN_INVALID;
> + return;
> + }
> +
> + rgn = hpb->rgn_tbl + srgn->rgn_idx;
> +
> + if (unlikely(rgn->rgn_state == HPB_RGN_INACTIVE)) {
> + dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> + "region %d subregion %d evicted\n",
> + srgn->rgn_idx, srgn->srgn_idx);
> + srgn->srgn_state = HPB_SRGN_INVALID;
> + return;
> + }
> + srgn->srgn_state = HPB_SRGN_VALID;
> +}
> +
> +static void ufshpb_map_req_compl_fn(struct request *req, blk_status_t
> error)
> +{
> + struct ufshpb_req *map_req = (struct ufshpb_req *) req->end_io_data;
> + struct ufshpb_lu *hpb = map_req->hpb;
> + struct ufshpb_subregion *srgn;
> + unsigned long flags;
> +
> + srgn = hpb->rgn_tbl[map_req->rgn_idx].srgn_tbl +
> + map_req->srgn_idx;
> +
> + ufshpb_clear_dirty_bitmap(hpb, srgn);
> + spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> + ufshpb_activate_subregion(hpb, srgn);
> + spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> +
> + ufshpb_put_map_req(map_req->hpb, map_req);
> +}
> +
> +static void ufshpb_set_read_buf_cmd(unsigned char *cdb, int rgn_idx,
> + int srgn_idx, int srgn_mem_size)
> +{
> + cdb[0] = UFSHPB_READ_BUFFER;
> + cdb[1] = UFSHPB_READ_BUFFER_ID;
> +
> + put_unaligned_be16(rgn_idx, &cdb[2]);
> + put_unaligned_be16(srgn_idx, &cdb[4]);
> + put_unaligned_be24(srgn_mem_size, &cdb[6]);
> +
> + cdb[9] = 0x00;
> +}
> +
> +static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
> + struct ufshpb_req *map_req, bool last)
> +{
> + struct request_queue *q;
> + struct request *req;
> + struct scsi_request *rq;
> + int mem_size = hpb->srgn_mem_size;
> + int ret = 0;
> + int i;
> +
> + q = hpb->sdev_ufs_lu->request_queue;
> + for (i = 0; i < hpb->pages_per_srgn; i++) {
> + ret = bio_add_pc_page(q, map_req->bio, map_req->mctx->m_page[i],
> + PAGE_SIZE, 0);
> + if (ret != PAGE_SIZE) {
> + dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> + "bio_add_pc_page fail %d - %d\n",
> + map_req->rgn_idx, map_req->srgn_idx);
> + return ret;
> + }
> + }
> +
> + req = map_req->req;
> +
> + blk_rq_append_bio(req, &map_req->bio);
> +
> + req->end_io_data = map_req;
> +
> + rq = scsi_req(req);
> +
> + if (unlikely(last))
> + mem_size = hpb->last_srgn_entries * HPB_ENTRY_SIZE;
> +
> + ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
> + map_req->srgn_idx, mem_size);
> + rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
> +
> + blk_execute_rq_nowait(q, NULL, req, 1, ufshpb_map_req_compl_fn);
> +
> + hpb->stats.map_req_cnt++;
> + return 0;
> +}
> +
> +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu
> *hpb,
> + bool last)
> +{
> + struct ufshpb_map_ctx *mctx;
> + u32 num_entries = hpb->entries_per_srgn;
> + int i, j;
> +
> + mctx = mempool_alloc(ufshpb_mctx_pool, GFP_KERNEL);
> + if (!mctx)
> + return NULL;
> +
> + mctx->m_page = kmem_cache_alloc(hpb->m_page_cache, GFP_KERNEL);
> + if (!mctx->m_page)
> + goto release_mctx;
> +
> + if (unlikely(last))
> + num_entries = hpb->last_srgn_entries;
> +
> + mctx->ppn_dirty = bitmap_zalloc(num_entries, GFP_KERNEL);
> + if (!mctx->ppn_dirty)
> + goto release_m_page;
> +
> + for (i = 0; i < hpb->pages_per_srgn; i++) {
> + mctx->m_page[i] = mempool_alloc(ufshpb_page_pool, GFP_KERNEL);
> + if (!mctx->m_page[i]) {
> + for (j = 0; j < i; j++)
> + mempool_free(mctx->m_page[j], ufshpb_page_pool);
> + goto release_ppn_dirty;
> + }
> + clear_page(page_address(mctx->m_page[i]));
> + }
> +
> + return mctx;
> +
> +release_ppn_dirty:
> + bitmap_free(mctx->ppn_dirty);
> +release_m_page:
> + kmem_cache_free(hpb->m_page_cache, mctx->m_page);
> +release_mctx:
> + mempool_free(mctx, ufshpb_mctx_pool);
> + return NULL;
> +}
> +
> +static void ufshpb_put_map_ctx(struct ufshpb_lu *hpb,
> + struct ufshpb_map_ctx *mctx)
> +{
> + int i;
> +
> + for (i = 0; i < hpb->pages_per_srgn; i++)
> + mempool_free(mctx->m_page[i], ufshpb_page_pool);
> +
> + bitmap_free(mctx->ppn_dirty);
> + kmem_cache_free(hpb->m_page_cache, mctx->m_page);
> + mempool_free(mctx, ufshpb_mctx_pool);
> +}
> +
> +static int ufshpb_check_srgns_issue_state(struct ufshpb_lu *hpb,
> + struct ufshpb_region *rgn)
> +{
> + struct ufshpb_subregion *srgn;
> + int srgn_idx;
> +
> + for_each_sub_region(rgn, srgn_idx, srgn)
> + if (srgn->srgn_state == HPB_SRGN_ISSUED)
> + return -EPERM;
> +
> + return 0;
> +}
> +
> +static void ufshpb_add_lru_info(struct victim_select_info *lru_info,
> + struct ufshpb_region *rgn)
> +{
> + rgn->rgn_state = HPB_RGN_ACTIVE;
> + list_add_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
> + atomic_inc(&lru_info->active_cnt);
> +}
> +
> +static void ufshpb_hit_lru_info(struct victim_select_info *lru_info,
> + struct ufshpb_region *rgn)
> +{
> + list_move_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
> +}
> +
> +static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu
> *hpb)
> +{
> + struct victim_select_info *lru_info = &hpb->lru_info;
> + struct ufshpb_region *rgn, *victim_rgn = NULL;
> +
> + list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn) {
> + if (!rgn) {
> + dev_err(&hpb->sdev_ufs_lu->sdev_dev,
> + "%s: no region allocated\n",
> + __func__);
> + return NULL;
> + }
> + if (ufshpb_check_srgns_issue_state(hpb, rgn))
> + continue;
> +
> + victim_rgn = rgn;
> + break;
> + }
> +
> + return victim_rgn;
> +}
> +
> +static void ufshpb_cleanup_lru_info(struct victim_select_info
> *lru_info,
> + struct ufshpb_region *rgn)
> +{
> + list_del_init(&rgn->list_lru_rgn);
> + rgn->rgn_state = HPB_RGN_INACTIVE;
> + atomic_dec(&lru_info->active_cnt);
> +}
> +
> +static void ufshpb_purge_active_subregion(struct ufshpb_lu *hpb,
> + struct ufshpb_subregion *srgn)
> +{
> + if (srgn->srgn_state != HPB_SRGN_UNUSED) {
> + ufshpb_put_map_ctx(hpb, srgn->mctx);
> + srgn->srgn_state = HPB_SRGN_UNUSED;
> + srgn->mctx = NULL;
> + }
> +}
> +
> +static void __ufshpb_evict_region(struct ufshpb_lu *hpb,
> + struct ufshpb_region *rgn)
> +{
> + struct victim_select_info *lru_info;
> + struct ufshpb_subregion *srgn;
> + int srgn_idx;
> +
> + lru_info = &hpb->lru_info;
> +
> + dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, "evict region %d\n",
> rgn->rgn_idx);
> +
> + ufshpb_cleanup_lru_info(lru_info, rgn);
> +
> + for_each_sub_region(rgn, srgn_idx, srgn)
> + ufshpb_purge_active_subregion(hpb, srgn);
> +}
> +
> +static int ufshpb_evict_region(struct ufshpb_lu *hpb, struct
> ufshpb_region *rgn)
> +{
> + unsigned long flags;
> + int ret = 0;
> +
> + spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> + if (rgn->rgn_state == HPB_RGN_PINNED) {
> + dev_warn(&hpb->sdev_ufs_lu->sdev_dev,
> + "pinned region cannot drop-out. region %d\n",
> + rgn->rgn_idx);
> + goto out;
> + }
> + if (!list_empty(&rgn->list_lru_rgn)) {
> + if (ufshpb_check_srgns_issue_state(hpb, rgn)) {
> + ret = -EBUSY;
> + goto out;
> + }
> +
> + __ufshpb_evict_region(hpb, rgn);
> + }
> +out:
> + spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> + return ret;
> +}
> +
> +static int ufshpb_issue_map_req(struct ufshpb_lu *hpb,
> + struct ufshpb_region *rgn,
> + struct ufshpb_subregion *srgn)
> +{
> + struct ufshpb_req *map_req;
> + unsigned long flags;
> + int ret;
> + int err = -EAGAIN;
> + bool alloc_required = false;
> + enum HPB_SRGN_STATE state = HPB_SRGN_INVALID;
> +
> + spin_lock_irqsave(&hpb->rgn_state_lock, flags);
> +
> + if (ufshpb_get_state(hpb) != HPB_PRESENT) {
> + dev_notice(&hpb->sdev_ufs_lu->sdev_dev,
> + "%s: ufshpb state is not PRESENT\n", __func__);
> + goto unlock_out;
> + }
> +
> + if ((rgn->rgn_state == HPB_RGN_INACTIVE) &&
> + (srgn->srgn_state == HPB_SRGN_INVALID)) {
> + err = 0;
> + goto unlock_out;
> + }
> +
> + if (srgn->srgn_state == HPB_SRGN_UNUSED)
> + alloc_required = true;
> +
> + /*
> + * If the subregion is already ISSUED state,
> + * a specific event (e.g., GC or wear-leveling, etc.) occurs in
> + * the device and HPB response for map loading is received.
> + * In this case, after finishing the HPB_READ_BUFFER,
> + * the next HPB_READ_BUFFER is performed again to obtain the latest
> + * map data.
> + */
> + if (srgn->srgn_state == HPB_SRGN_ISSUED)
> + goto unlock_out;
> +
> + srgn->srgn_state = HPB_SRGN_ISSUED;
> + spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
> +
> + if (alloc_required) {
> + if (srgn->mctx) {
Can this really happen?
alloc_required is true if srgn->srgn_state == HPB_SRGN_UNUSED.
ufshpb_put_map_ctx() is called and srgn->srgn_state is given
HPB_SRGN_UNUSED together in ufshpb_purge_active_subregion().
Do I miss anything?
It is not normal case, but it is for preventing memory leak on abnormal
case.
Thanks,
Daejun
Abnormal how? Could you please give an example?
Thanks,
Can Guo