hisi_sas: Add slot init code

Add functionality to init slot indexing.

Slot indexing is for the host to track which slots (or tags) are free
and which are used.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -66,6 +66,10 @@ struct hisi_hba {
 
 	int n_phy;
 
+
+	int slot_index_count;
+	unsigned long *slot_index_tags;
+
 	/* SCSI/SAS glue */
 	struct sas_ha_struct sha;
 	struct Scsi_Host *shost;

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -12,6 +12,21 @@
 #include "hisi_sas.h"
 #define DRV_NAME "hisi_sas"
 
+static void hisi_sas_slot_index_clear(struct hisi_hba *hisi_hba, int slot_idx)
+{
+	void *bitmap = hisi_hba->slot_index_tags;
+
+	clear_bit(slot_idx, bitmap);
+}
+
+static void hisi_sas_slot_index_init(struct hisi_hba *hisi_hba)
+{
+	int i;
+
+	for (i = 0; i < hisi_hba->slot_index_count; ++i)
+		hisi_sas_slot_index_clear(hisi_hba, i);
+}
+
 static struct scsi_transport_template *hisi_sas_stt;
 
 static struct scsi_host_template hisi_sas_sht = {
@@ -102,6 +117,12 @@ static int hisi_sas_alloc(struct hisi_hba *hisi_hba, struct Scsi_Host *shost)
 
 	memset(hisi_hba->breakpoint, 0, s);
 
+	hisi_hba->slot_index_count = HISI_SAS_COMMAND_ENTRIES;
+	s = hisi_hba->slot_index_count / sizeof(unsigned long);
+	hisi_hba->slot_index_tags = devm_kzalloc(dev, s, GFP_KERNEL);
+	if (!hisi_hba->slot_index_tags)
+		goto err_out;
+
 	hisi_hba->sge_page_pool = dma_pool_create("status_sge", dev,
 				sizeof(struct hisi_sas_sge_page), 16, 0);
 	if (!hisi_hba->sge_page_pool)
@@ -121,6 +142,8 @@ static int hisi_sas_alloc(struct hisi_hba *hisi_hba, struct Scsi_Host *shost)
 		goto err_out;
 	memset(hisi_hba->sata_breakpoint, 0, s);
 
+	hisi_sas_slot_index_init(hisi_hba);
+
 	return 0;
 err_out:
 	return -ENOMEM;