scsi: pm8001: Introduce ccb alloc/free helpers

Introduce the pm8001_ccb_alloc() and pm8001_ccb_free() helpers to replace
the typical code patterns:

	res = pm8001_tag_alloc(pm8001_ha, &ccb_tag);
	if (res)
		...
	ccb = &pm8001_ha->ccb_info[ccb_tag];
	ccb->device = pm8001_ha_dev;
	ccb->ccb_tag = ccb_tag;
	ccb->task = task;
	ccb->n_elem = 0;

and

	ccb->task = NULL;
	ccb->ccb_tag = PM8001_INVALID_TAG;
	pm8001_tag_free(pm8001_ha, tag);

With the simpler function calls:

	ccb = pm8001_ccb_alloc(pm8001_ha, pm8001_ha_dev, task);
	if (!ccb)
		...

and

	pm8001_ccb_free(pm8001_ha, ccb);

The pm8001_ccb_alloc() helper ensures that all fields of the ccb info
structure for the newly allocated tag are all initialized, except the
buf_prd field. The pm8001_ccb_free() helper clears the initialized fields
and the ccb tag to ensure that iteration over the adapter ccb_info array
detects ccbs that are in use.

All call site of the pm8001_tag_alloc() function that use a ccb info
associated with an allocated tag are converted to use the new helpers.

Link: https://lore.kernel.org/r/20220220031810.738362-27-damien.lemoal@opensource.wdc.comReviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/pm8001/pm8001_sas.c

@@ -74,7 +74,7 @@ void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
   * @pm8001_ha: our hba struct
   * @tag_out: the found empty tag .
   */
-inline int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
+int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
 {
 	unsigned int tag;
 	void *bitmap = pm8001_ha->tags;
@@ -381,7 +381,7 @@ int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
 	struct pm8001_port *port = NULL;
 	struct sas_task *t = task;
 	struct pm8001_ccb_info *ccb;
-	u32 tag = 0xdeadbeef, rc = 0, n_elem = 0;
+	u32 rc = 0, n_elem = 0;
 	unsigned long flags = 0;
 	enum sas_protocol task_proto = t->task_proto;
 	struct sas_tmf_task *tmf = task->tmf;
@@ -427,10 +427,12 @@ int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
 				continue;
 			}
 		}
-		rc = pm8001_tag_alloc(pm8001_ha, &tag);
-		if (rc)
+
+		ccb = pm8001_ccb_alloc(pm8001_ha, pm8001_dev, t);
+		if (!ccb) {
+			rc = -SAS_QUEUE_FULL;
 			goto err_out;
-		ccb = &pm8001_ha->ccb_info[tag];
+		}
 
 		if (!sas_protocol_ata(task_proto)) {
 			if (t->num_scatter) {
@@ -440,7 +442,7 @@ int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
 					t->data_dir);
 				if (!n_elem) {
 					rc = -ENOMEM;
-					goto err_out_tag;
+					goto err_out_ccb;
 				}
 			}
 		} else {
@@ -449,9 +451,7 @@ int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
 
 		t->lldd_task = ccb;
 		ccb->n_elem = n_elem;
-		ccb->ccb_tag = tag;
-		ccb->task = t;
-		ccb->device = pm8001_dev;
+
 		switch (task_proto) {
 		case SAS_PROTOCOL_SMP:
 			atomic_inc(&pm8001_dev->running_req);
@@ -480,15 +480,15 @@ int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
 		if (rc) {
 			pm8001_dbg(pm8001_ha, IO, "rc is %x\n", rc);
 			atomic_dec(&pm8001_dev->running_req);
-			goto err_out_tag;
+			goto err_out_ccb;
 		}
 		/* TODO: select normal or high priority */
 	} while (0);
 	rc = 0;
 	goto out_done;
 
-err_out_tag:
-	pm8001_tag_free(pm8001_ha, tag);
+err_out_ccb:
+	pm8001_ccb_free(pm8001_ha, ccb);
 err_out:
 	dev_printk(KERN_ERR, pm8001_ha->dev, "pm8001 exec failed[%d]!\n", rc);
 	if (!sas_protocol_ata(task_proto))
@@ -548,10 +548,7 @@ void pm8001_ccb_task_free(struct pm8001_hba_info *pm8001_ha,
 	}
 
 	task->lldd_task = NULL;
-	ccb->task = NULL;
-	ccb->ccb_tag = PM8001_INVALID_TAG;
-	ccb->open_retry = 0;
-	pm8001_tag_free(pm8001_ha, ccb_idx);
+	pm8001_ccb_free(pm8001_ha, ccb);
 }
 
 /**
@@ -707,7 +704,6 @@ pm8001_exec_internal_task_abort(struct pm8001_hba_info *pm8001_ha,
 	u32 task_tag)
 {
 	int res, retry;
-	u32 ccb_tag;
 	struct pm8001_ccb_info *ccb;
 	struct sas_task *task = NULL;
 
@@ -724,23 +720,19 @@ pm8001_exec_internal_task_abort(struct pm8001_hba_info *pm8001_ha,
 			jiffies + PM8001_TASK_TIMEOUT * HZ;
 		add_timer(&task->slow_task->timer);
 
-		res = pm8001_tag_alloc(pm8001_ha, &ccb_tag);
-		if (res)
+		ccb = pm8001_ccb_alloc(pm8001_ha, pm8001_dev, task);
+		if (!ccb) {
+			res = -SAS_QUEUE_FULL;
 			break;
-
-		ccb = &pm8001_ha->ccb_info[ccb_tag];
-		ccb->device = pm8001_dev;
-		ccb->ccb_tag = ccb_tag;
-		ccb->task = task;
-		ccb->n_elem = 0;
+		}
 
 		res = PM8001_CHIP_DISP->task_abort(pm8001_ha, pm8001_dev, flag,
-						   task_tag, ccb_tag);
+						   task_tag, ccb->ccb_tag);
 		if (res) {
 			del_timer(&task->slow_task->timer);
 			pm8001_dbg(pm8001_ha, FAIL,
 				   "Executing internal task failed\n");
-			pm8001_tag_free(pm8001_ha, ccb_tag);
+			pm8001_ccb_free(pm8001_ha, ccb);
 			break;
 		}
 

drivers/scsi/pm8001/pm8001_sas.h

@@ -734,6 +734,53 @@ extern const struct attribute_group *pm8001_host_groups[];
 
 #define PM8001_INVALID_TAG	((u32)-1)
 
+/*
+ * Allocate a new tag and return the corresponding ccb after initializing it.
+ */
+static inline struct pm8001_ccb_info *
+pm8001_ccb_alloc(struct pm8001_hba_info *pm8001_ha,
+		 struct pm8001_device *dev, struct sas_task *task)
+{
+	struct pm8001_ccb_info *ccb;
+	u32 tag;
+
+	if (pm8001_tag_alloc(pm8001_ha, &tag)) {
+		pm8001_dbg(pm8001_ha, FAIL, "Failed to allocate a tag\n");
+		return NULL;
+	}
+
+	ccb = &pm8001_ha->ccb_info[tag];
+	ccb->task = task;
+	ccb->n_elem = 0;
+	ccb->ccb_tag = tag;
+	ccb->device = dev;
+	ccb->fw_control_context = NULL;
+	ccb->open_retry = 0;
+
+	return ccb;
+}
+
+/*
+ * Free the tag of an initialized ccb.
+ */
+static inline void pm8001_ccb_free(struct pm8001_hba_info *pm8001_ha,
+				   struct pm8001_ccb_info *ccb)
+{
+	u32 tag = ccb->ccb_tag;
+
+	/*
+	 * Cleanup the ccb to make sure that a manual scan of the adapter
+	 * ccb_info array can detect ccb's that are in use.
+	 * C.f. pm8001_open_reject_retry()
+	 */
+	ccb->task = NULL;
+	ccb->ccb_tag = PM8001_INVALID_TAG;
+	ccb->device = NULL;
+	ccb->fw_control_context = NULL;
+
+	pm8001_tag_free(pm8001_ha, tag);
+}
+
 static inline void
 pm8001_ccb_task_free_done(struct pm8001_hba_info *pm8001_ha,
 			struct sas_task *task, struct pm8001_ccb_info *ccb,

drivers/scsi/pm8001/pm80xx_hwi.c

@@ -1767,8 +1767,6 @@ pm80xx_chip_interrupt_disable(struct pm8001_hba_info *pm8001_ha, u8 vec)
 static void pm80xx_send_abort_all(struct pm8001_hba_info *pm8001_ha,
 		struct pm8001_device *pm8001_ha_dev)
 {
-	int res;
-	u32 ccb_tag;
 	struct pm8001_ccb_info *ccb;
 	struct sas_task *task = NULL;
 	struct task_abort_req task_abort;
@@ -1790,31 +1788,25 @@ static void pm80xx_send_abort_all(struct pm8001_hba_info *pm8001_ha,
 
 	task->task_done = pm8001_task_done;
 
-	res = pm8001_tag_alloc(pm8001_ha, &ccb_tag);
-	if (res) {
+	ccb = pm8001_ccb_alloc(pm8001_ha, pm8001_ha_dev, task);
+	if (!ccb) {
 		sas_free_task(task);
 		return;
 	}
 
-	ccb = &pm8001_ha->ccb_info[ccb_tag];
-	ccb->device = pm8001_ha_dev;
-	ccb->ccb_tag = ccb_tag;
-	ccb->task = task;
-	ccb->n_elem = 0;
-
 	circularQ = &pm8001_ha->inbnd_q_tbl[0];
 
 	memset(&task_abort, 0, sizeof(task_abort));
 	task_abort.abort_all = cpu_to_le32(1);
 	task_abort.device_id = cpu_to_le32(pm8001_ha_dev->device_id);
-	task_abort.tag = cpu_to_le32(ccb_tag);
+	task_abort.tag = cpu_to_le32(ccb->ccb_tag);
 
 	ret = pm8001_mpi_build_cmd(pm8001_ha, circularQ, opc, &task_abort,
 			sizeof(task_abort), 0);
 	pm8001_dbg(pm8001_ha, FAIL, "Executing abort task end\n");
 	if (ret) {
 		sas_free_task(task);
-		pm8001_tag_free(pm8001_ha, ccb_tag);
+		pm8001_ccb_free(pm8001_ha, ccb);
 	}
 }
 
@@ -1823,7 +1815,6 @@ static void pm80xx_send_read_log(struct pm8001_hba_info *pm8001_ha,
 {
 	struct sata_start_req sata_cmd;
 	int res;
-	u32 ccb_tag;
 	struct pm8001_ccb_info *ccb;
 	struct sas_task *task = NULL;
 	struct host_to_dev_fis fis;
@@ -1839,20 +1830,13 @@ static void pm80xx_send_read_log(struct pm8001_hba_info *pm8001_ha,
 	}
 	task->task_done = pm8001_task_done;
 
-	res = pm8001_tag_alloc(pm8001_ha, &ccb_tag);
-	if (res) {
-		sas_free_task(task);
-		pm8001_dbg(pm8001_ha, FAIL, "cannot allocate tag !!!\n");
-		return;
-	}
-
-	/* allocate domain device by ourselves as libsas
-	 * is not going to provide any
-	*/
+	/*
+	 * Allocate domain device by ourselves as libsas is not going to
+	 * provide any.
+	 */
 	dev = kzalloc(sizeof(struct domain_device), GFP_ATOMIC);
 	if (!dev) {
 		sas_free_task(task);
-		pm8001_tag_free(pm8001_ha, ccb_tag);
 		pm8001_dbg(pm8001_ha, FAIL,
 			   "Domain device cannot be allocated\n");
 		return;
@@ -1861,11 +1845,13 @@ static void pm80xx_send_read_log(struct pm8001_hba_info *pm8001_ha,
 	task->dev = dev;
 	task->dev->lldd_dev = pm8001_ha_dev;
 
-	ccb = &pm8001_ha->ccb_info[ccb_tag];
-	ccb->device = pm8001_ha_dev;
-	ccb->ccb_tag = ccb_tag;
-	ccb->task = task;
-	ccb->n_elem = 0;
+	ccb = pm8001_ccb_alloc(pm8001_ha, pm8001_ha_dev, task);
+	if (!ccb) {
+		sas_free_task(task);
+		kfree(dev);
+		return;
+	}
+
 	pm8001_ha_dev->id |= NCQ_READ_LOG_FLAG;
 	pm8001_ha_dev->id |= NCQ_2ND_RLE_FLAG;
 
@@ -1880,7 +1866,7 @@ static void pm80xx_send_read_log(struct pm8001_hba_info *pm8001_ha,
 	fis.lbal = 0x10;
 	fis.sector_count = 0x1;
 
-	sata_cmd.tag = cpu_to_le32(ccb_tag);
+	sata_cmd.tag = cpu_to_le32(ccb->ccb_tag);
 	sata_cmd.device_id = cpu_to_le32(pm8001_ha_dev->device_id);
 	sata_cmd.ncqtag_atap_dir_m_dad = cpu_to_le32(((0x1 << 7) | (0x5 << 9)));
 	memcpy(&sata_cmd.sata_fis, &fis, sizeof(struct host_to_dev_fis));
@@ -1890,7 +1876,7 @@ static void pm80xx_send_read_log(struct pm8001_hba_info *pm8001_ha,
 	pm8001_dbg(pm8001_ha, FAIL, "Executing read log end\n");
 	if (res) {
 		sas_free_task(task);
-		pm8001_tag_free(pm8001_ha, ccb_tag);
+		pm8001_ccb_free(pm8001_ha, ccb);
 		kfree(dev);
 	}
 }
@@ -4834,7 +4820,7 @@ static int pm80xx_chip_reg_dev_req(struct pm8001_hba_info *pm8001_ha,
 	u32 stp_sspsmp_sata = 0x4;
 	struct inbound_queue_table *circularQ;
 	u32 linkrate, phy_id;
-	int rc, tag = 0xdeadbeef;
+	int rc;
 	struct pm8001_ccb_info *ccb;
 	u8 retryFlag = 0x1;
 	u16 firstBurstSize = 0;
@@ -4845,13 +4831,11 @@ static int pm80xx_chip_reg_dev_req(struct pm8001_hba_info *pm8001_ha,
 	circularQ = &pm8001_ha->inbnd_q_tbl[0];
 
 	memset(&payload, 0, sizeof(payload));
-	rc = pm8001_tag_alloc(pm8001_ha, &tag);
-	if (rc)
-		return rc;
-	ccb = &pm8001_ha->ccb_info[tag];
-	ccb->device = pm8001_dev;
-	ccb->ccb_tag = tag;
-	payload.tag = cpu_to_le32(tag);
+	ccb = pm8001_ccb_alloc(pm8001_ha, pm8001_dev, NULL);
+	if (!ccb)
+		return -SAS_QUEUE_FULL;
+
+	payload.tag = cpu_to_le32(ccb->ccb_tag);
 
 	if (flag == 1) {
 		stp_sspsmp_sata = 0x02; /*direct attached sata */
@@ -4888,7 +4872,7 @@ static int pm80xx_chip_reg_dev_req(struct pm8001_hba_info *pm8001_ha,
 	rc = pm8001_mpi_build_cmd(pm8001_ha, circularQ, opc, &payload,
 			sizeof(payload), 0);
 	if (rc)
-		pm8001_tag_free(pm8001_ha, tag);
+		pm8001_ccb_free(pm8001_ha, ccb);
 
 	return rc;
 }