[PATCH v3 5/9] scsi: ufshpb: Region inactivation in host mode

[Avri Altman]

I host mode, the host is expected to send HPB-WRITE-BUFFER with
buffer-id = 0x1 when it inactivates a region.

Use the map-requests pool as there is no point in assigning a
designated cache for umap-requests.

Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
---
 drivers/scsi/ufs/ufshpb.c | 120 ++++++++++++++++++++++++++++++++------
 drivers/scsi/ufs/ufshpb.h |   5 +-
 2 files changed, 105 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 9cb17c97cf93..3435a5507853 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -717,16 +717,15 @@ int ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 	return 0;
 }
 
-static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
-					     struct ufshpb_subregion *srgn)
+static struct ufshpb_req *ufshpb_get_req(struct ufshpb_lu *hpb,
+					 int rgn_idx, enum req_opf dir)
 {
-	struct ufshpb_req *map_req;
+	struct ufshpb_req *rq;
 	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)
+	rq = kmem_cache_alloc(hpb->map_req_cache, GFP_KERNEL);
+	if (!rq)
 		return NULL;
 
 retry:
@@ -738,36 +737,57 @@ static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
 		goto retry;
 	}
 
+	req = blk_get_request(hpb->sdev_ufs_lu->request_queue,
+			      dir, 0);
 	if (IS_ERR(req))
-		goto free_map_req;
+		goto free_rq;
+
+	rq->hpb = hpb;
+	rq->req = req;
+	rq->rb.rgn_idx = rgn_idx;
+
+	return rq;
+
+free_rq:
+	kmem_cache_free(hpb->map_req_cache, rq);
+	return NULL;
+}
+
+static void ufshpb_put_req(struct ufshpb_lu *hpb, struct ufshpb_req *rq)
+{
+	blk_put_request(rq->req);
+	kmem_cache_free(hpb->map_req_cache, rq);
+}
+
+static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
+					     struct ufshpb_subregion *srgn)
+{
+	struct ufshpb_req *map_req;
+	struct bio *bio;
+
+	map_req = ufshpb_get_req(hpb, srgn->rgn_idx, REQ_OP_SCSI_IN);
+	if (!map_req)
+		return NULL;
 
 	bio = bio_alloc(GFP_KERNEL, hpb->pages_per_srgn);
 	if (!bio) {
-		blk_put_request(req);
-		goto free_map_req;
+		ufshpb_put_req(hpb, map_req);
+		return NULL;
 	}
 
-	map_req->hpb = hpb;
-	map_req->req = req;
 	map_req->bio = bio;
 
-	map_req->rb.rgn_idx = srgn->rgn_idx;
 	map_req->rb.srgn_idx = srgn->srgn_idx;
 	map_req->rb.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)
+			       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);
+	ufshpb_put_req(hpb, map_req);
 }
 
 static int ufshpb_clear_dirty_bitmap(struct ufshpb_lu *hpb,
@@ -829,6 +849,13 @@ static void ufshpb_activate_subregion(struct ufshpb_lu *hpb,
 	srgn->srgn_state = HPB_SRGN_VALID;
 }
 
+static void ufshpb_umap_req_compl_fn(struct request *req, blk_status_t error)
+{
+	struct ufshpb_req *umap_req = (struct ufshpb_req *)req->end_io_data;
+
+	ufshpb_put_req(umap_req->hpb, umap_req);
+}
+
 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;
@@ -847,6 +874,14 @@ static void ufshpb_map_req_compl_fn(struct request *req, blk_status_t error)
 	ufshpb_put_map_req(map_req->hpb, map_req);
 }
 
+static void ufshpb_set_unmap_cmd(unsigned char *cdb, int rgn_idx)
+{
+	cdb[0] = UFSHPB_WRITE_BUFFER;
+	cdb[1] = UFSHPB_WRITE_BUFFER_ID;
+	put_unaligned_be16(rgn_idx, &cdb[2]);
+	cdb[9] = 0x00;
+}
+
 static void ufshpb_set_read_buf_cmd(unsigned char *cdb, int rgn_idx,
 					   int srgn_idx, int srgn_mem_size)
 {
@@ -860,6 +895,27 @@ static void ufshpb_set_read_buf_cmd(unsigned char *cdb, int rgn_idx,
 	cdb[9] = 0x00;
 }
 
+static int ufshpb_execute_umap_req(struct ufshpb_lu *hpb,
+				   struct ufshpb_req *umap_req)
+{
+	struct request_queue *q;
+	struct request *req;
+	struct scsi_request *rq;
+
+	q = hpb->sdev_ufs_lu->request_queue;
+	req = umap_req->req;
+	req->timeout = 0;
+	req->end_io_data = (void *)umap_req;
+	rq = scsi_req(req);
+	ufshpb_set_unmap_cmd(rq->cmd, umap_req->rb.rgn_idx);
+	rq->cmd_len = HPB_WRITE_BUFFER_CMD_LENGTH;
+
+	blk_execute_rq_nowait(q, NULL, req, 1, ufshpb_umap_req_compl_fn);
+
+	hpb->stats.umap_req_cnt++;
+	return 0;
+}
+
 static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
 				  struct ufshpb_req *map_req, bool last)
 {
@@ -1028,6 +1084,25 @@ static void ufshpb_purge_active_subregion(struct ufshpb_lu *hpb,
 	}
 }
 
+static int ufshpb_issue_umap_req(struct ufshpb_lu *hpb,
+				 struct ufshpb_region *rgn)
+{
+	struct ufshpb_req *umap_req;
+
+	umap_req = ufshpb_get_req(hpb, rgn->rgn_idx, REQ_OP_SCSI_OUT);
+	if (!umap_req)
+		return -ENOMEM;
+
+	if (ufshpb_execute_umap_req(hpb, umap_req))
+		goto free_umap_req;
+
+	return 0;
+
+free_umap_req:
+	ufshpb_put_req(hpb, umap_req);
+	return -EAGAIN;
+}
+
 static void __ufshpb_evict_region(struct ufshpb_lu *hpb,
 				  struct ufshpb_region *rgn)
 {
@@ -1035,6 +1110,10 @@ static void __ufshpb_evict_region(struct ufshpb_lu *hpb,
 	struct ufshpb_subregion *srgn;
 	int srgn_idx;
 
+
+	if (hpb->is_hcm && ufshpb_issue_umap_req(hpb, rgn))
+		return;
+
 	lru_info = &hpb->lru_info;
 
 	dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, "evict region %d\n", rgn->rgn_idx);
@@ -1759,6 +1838,7 @@ ufshpb_sysfs_attr_show_func(rb_noti_cnt);
 ufshpb_sysfs_attr_show_func(rb_active_cnt);
 ufshpb_sysfs_attr_show_func(rb_inactive_cnt);
 ufshpb_sysfs_attr_show_func(map_req_cnt);
+ufshpb_sysfs_attr_show_func(umap_req_cnt);
 
 static struct attribute *hpb_dev_stat_attrs[] = {
 	&dev_attr_hit_cnt.attr,
@@ -1767,6 +1847,7 @@ static struct attribute *hpb_dev_stat_attrs[] = {
 	&dev_attr_rb_active_cnt.attr,
 	&dev_attr_rb_inactive_cnt.attr,
 	&dev_attr_map_req_cnt.attr,
+	&dev_attr_umap_req_cnt.attr,
 	NULL,
 };
 
@@ -1881,6 +1962,7 @@ static void ufshpb_stat_init(struct ufshpb_lu *hpb)
 	hpb->stats.rb_active_cnt = 0;
 	hpb->stats.rb_inactive_cnt = 0;
 	hpb->stats.map_req_cnt = 0;
+	hpb->stats.umap_req_cnt = 0;
 }
 
 static void ufshpb_param_init(struct ufshpb_lu *hpb)
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
index 0a41df919f06..13ec49ba260d 100644
--- a/drivers/scsi/ufs/ufshpb.h
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -36,11 +36,13 @@
 /* hpb vender defined opcode */
 #define UFSHPB_READ				0xF8
 #define UFSHPB_READ_BUFFER			0xF9
-#define UFSHPB_READ_BUFFER_ID			0x01
 #define UFSHPB_WRITE_BUFFER			0xFA
+#define UFSHPB_READ_BUFFER_ID			0x01
+#define UFSHPB_WRITE_BUFFER_ID			0x01
 #define UFSHPB_WRITE_BUFFER_PREFETCH_ID		0x02
 #define MAX_HPB_READ_ID				0x7F
 #define HPB_READ_BUFFER_CMD_LENGTH		10
+#define HPB_WRITE_BUFFER_CMD_LENGTH		10
 #define LU_ENABLED_HPB_FUNC			0x02
 
 #define HPB_RESET_REQ_RETRIES			10
@@ -182,6 +184,7 @@ struct ufshpb_stats {
 	u64 rb_inactive_cnt;
 	u64 map_req_cnt;
 	u64 pre_req_cnt;
+	u64 umap_req_cnt;
 };
 
 struct ufshpb_lu {
-- 
2.25.1