libata: Add support for SCT Write Same

SATA drives may support write same via SCT. This is useful
for setting the drive contents to a specific pattern (0's).

Translate a SCSI WRITE SAME 16 command to be either a DSM TRIM
command or an SCT Write Same command.

Based on the UNMAP flag:
  - When set translate to DSM TRIM
  - When not set translate to SCT Write Same

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>

2 files changed, 213 insertions, 29 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 84e7f48ca83e..08d9c8e731b3 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1159,8 +1159,6 @@ static void ata_scsi_sdev_config(struct scsi_device *sdev)
 {
         sdev->use_10_for_rw = 1;
         sdev->use_10_for_ms = 1;
-        sdev->no_report_opcodes = 1;
-        sdev->no_write_same = 1;
 
         /* Schedule policy is determined by ->qc_defer() callback and
          * it needs to see every deferred qc.  Set dev_blocked to 1 to
@@ -3287,7 +3285,7 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
  * @cmd: SCSI command being translated
  * @num: Maximum number of entries (nominally 64).
  * @sector: Starting sector
- * @count: Total Range of request
+ * @count: Total Range of request in logical sectors
  *
  * Rewrite the WRITE SAME descriptor to be a DSM TRIM little-endian formatted
  * descriptor.
@@ -3330,6 +3328,45 @@ static unsigned int ata_format_dsm_trim_descr(struct scsi_cmnd *cmd, u32 num,
         return used_bytes;
 }
 
+/**
+ * ata_format_dsm_trim_descr() - SATL Write Same to ATA SCT Write Same
+ * @cmd: SCSI command being translated
+ * @lba: Starting sector
+ * @num: Number of logical sectors to be zero'd.
+ *
+ * Rewrite the WRITE SAME descriptor to be an SCT Write Same formatted
+ * descriptor.
+ * NOTE: Writes a pattern (0's) in the foreground.
+ *       Large write-same requents can timeout.
+ */
+static void ata_format_sct_write_same(struct scsi_cmnd *cmd, u64 lba, u64 num)
+{
+        u16 *sctpg;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ata_scsi_rbuf_lock, flags);
+        sctpg = ((void *)ata_scsi_rbuf);
+
+        put_unaligned_le16(0x0002,  &sctpg[0]); /* SCT_ACT_WRITE_SAME */
+        put_unaligned_le16(0x0101,  &sctpg[1]); /* WRITE PTRN FG */
+        put_unaligned_le64(lba,     &sctpg[2]);
+        put_unaligned_le64(num,     &sctpg[6]);
+        put_unaligned_le32(0u,      &sctpg[10]);
+
+        sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd), sctpg, 512);
+        spin_unlock_irqrestore(&ata_scsi_rbuf_lock, flags);
+}
+
+/**
+ * ata_scsi_write_same_xlat() - SATL Write Same to ATA SCT Write Same
+ * @qc: Command to be translated
+ *
+ * Translate a SCSI WRITE SAME command to be either a DSM TRIM command or
+ * an SCT Write Same command.
+ * Based on WRITE SAME has the UNMAP flag
+ *   When set translate to DSM TRIM
+ *   When clear translate to SCT Write Same
+ */
 static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
 {
         struct ata_taskfile *tf = &qc->tf;
@@ -3342,6 +3379,7 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
         u32 size;
         u16 fp;
         u8 bp = 0xff;
+        u8 unmap = cdb[1] & 0x8;
 
         /* we may not issue DMA commands if no DMA mode is set */
         if (unlikely(!dev->dma_mode))
@@ -3353,11 +3391,26 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
         }
         scsi_16_lba_len(cdb, &block, &n_block);
 
-        /* for now we only support WRITE SAME with the unmap bit set */
-        if (unlikely(!(cdb[1] & 0x8))) {
-                fp = 1;
-                bp = 3;
-                goto invalid_fld;
+        if (unmap) {
+                /* If trim is not enabled the cmd is invalid. */
+                if ((dev->horkage & ATA_HORKAGE_NOTRIM) ||
+                    !ata_id_has_trim(dev->id)) {
+                        fp = 1;
+                        bp = 3;
+                        goto invalid_fld;
+                }
+                /* If the request is too large the cmd is invalid */
+                if (n_block > 0xffff * trmax) {
+                        fp = 2;
+                        goto invalid_fld;
+                }
+        } else {
+                /* If write same is not available the cmd is invalid */
+                if (!ata_id_sct_write_same(dev->id)) {
+                        fp = 1;
+                        bp = 3;
+                        goto invalid_fld;
+                }
         }
 
         /*
@@ -3367,30 +3420,42 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
         if (!scsi_sg_count(scmd))
                 goto invalid_param_len;
 
-        if (n_block <= 0xffff * trmax) {
+        if (unmap) {
                 size = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);
+                if (ata_ncq_enabled(dev) && ata_fpdma_dsm_supported(dev)) {
+                        /* Newer devices support queued TRIM commands */
+                        tf->protocol = ATA_PROT_NCQ;
+                        tf->command = ATA_CMD_FPDMA_SEND;
+                        tf->hob_nsect = ATA_SUBCMD_FPDMA_SEND_DSM & 0x1f;
+                        tf->nsect = qc->tag << 3;
+                        tf->hob_feature = (size / 512) >> 8;
+                        tf->feature = size / 512;
+
+                        tf->auxiliary = 1;
+                } else {
+                        tf->protocol = ATA_PROT_DMA;
+                        tf->hob_feature = 0;
+                        tf->feature = ATA_DSM_TRIM;
+                        tf->hob_nsect = (size / 512) >> 8;
+                        tf->nsect = size / 512;
+                        tf->command = ATA_CMD_DSM;
+                }
         } else {
-                fp = 2;
-                goto invalid_fld;
-        }
-
-        if (ata_ncq_enabled(dev) && ata_fpdma_dsm_supported(dev)) {
-                /* Newer devices support queued TRIM commands */
-                tf->protocol = ATA_PROT_NCQ;
-                tf->command = ATA_CMD_FPDMA_SEND;
-                tf->hob_nsect = ATA_SUBCMD_FPDMA_SEND_DSM & 0x1f;
-                tf->nsect = qc->tag << 3;
-                tf->hob_feature = (size / 512) >> 8;
-                tf->feature = size / 512;
+                ata_format_sct_write_same(scmd, block, n_block);
 
-                tf->auxiliary = 1;
-        } else {
-                tf->protocol = ATA_PROT_DMA;
                 tf->hob_feature = 0;
-                tf->feature = ATA_DSM_TRIM;
-                tf->hob_nsect = (size / 512) >> 8;
-                tf->nsect = size / 512;
-                tf->command = ATA_CMD_DSM;
+                tf->feature = 0;
+                tf->hob_nsect = 0;
+                tf->nsect = 1;
+                tf->lbah = 0;
+                tf->lbam = 0;
+                tf->lbal = ATA_CMD_STANDBYNOW1;
+                tf->hob_lbah = 0;
+                tf->hob_lbam = 0;
+                tf->hob_lbal = 0;
+                tf->device = ATA_CMD_STANDBYNOW1;
+                tf->protocol = ATA_PROT_DMA;
+                tf->command = ATA_CMD_WRITE_LOG_DMA_EXT;
         }
 
         tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_LBA48 |
@@ -3414,6 +3479,76 @@ invalid_opcode:
 }
 
 /**
+ *      ata_scsiop_maint_in - Simulate a subset of MAINTENANCE_IN
+ *      @args: device MAINTENANCE_IN data / SCSI command of interest.
+ *      @rbuf: Response buffer, to which simulated SCSI cmd output is sent.
+ *
+ *      Yields a subset to satisfy scsi_report_opcode()
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host lock)
+ */
+static unsigned int ata_scsiop_maint_in(struct ata_scsi_args *args, u8 *rbuf)
+{
+        struct ata_device *dev = args->dev;
+        u8 *cdb = args->cmd->cmnd;
+        u8 supported = 0;
+        unsigned int err = 0;
+
+        if (cdb[2] != 1) {
+                ata_dev_warn(dev, "invalid command format %d\n", cdb[2]);
+                err = 2;
+                goto out;
+        }
+        switch (cdb[3]) {
+        case INQUIRY:
+        case MODE_SENSE:
+        case MODE_SENSE_10:
+        case READ_CAPACITY:
+        case SERVICE_ACTION_IN_16:
+        case REPORT_LUNS:
+        case REQUEST_SENSE:
+        case SYNCHRONIZE_CACHE:
+        case REZERO_UNIT:
+        case SEEK_6:
+        case SEEK_10:
+        case TEST_UNIT_READY:
+        case SEND_DIAGNOSTIC:
+        case MAINTENANCE_IN:
+        case READ_6:
+        case READ_10:
+        case READ_16:
+        case WRITE_6:
+        case WRITE_10:
+        case WRITE_16:
+        case ATA_12:
+        case ATA_16:
+        case VERIFY:
+        case VERIFY_16:
+        case MODE_SELECT:
+        case MODE_SELECT_10:
+        case START_STOP:
+                supported = 3;
+                break;
+        case WRITE_SAME_16:
+                if (ata_id_sct_write_same(dev->id))
+                        supported = 3;
+                break;
+        case ZBC_IN:
+        case ZBC_OUT:
+                if (ata_id_zoned_cap(dev->id) ||
+                    dev->class == ATA_DEV_ZAC)
+                        supported = 3;
+                break;
+        default:
+                break;
+        }
+out:
+        rbuf[1] = supported; /* supported */
+        return err;
+}
+
+/**
  *      ata_scsi_report_zones_complete - convert ATA output
  *      @qc: command structure returning the data
  *
@@ -4193,6 +4328,13 @@ void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd)
                         ata_scsi_invalid_field(dev, cmd, 1);
                 break;
 
+        case MAINTENANCE_IN:
+                if (scsicmd[1] == MI_REPORT_SUPPORTED_OPERATION_CODES)
+                        ata_scsi_rbuf_fill(&args, ata_scsiop_maint_in);
+                else
+                        ata_scsi_invalid_field(dev, cmd, 1);
+                break;
+
         /* all other commands */
         default:
                 ata_scsi_set_sense(dev, cmd, ILLEGAL_REQUEST, 0x20, 0x0);
@@ -4225,7 +4367,6 @@ int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
                 shost->max_lun = 1;
                 shost->max_channel = 1;
                 shost->max_cmd_len = 16;
-                shost->no_write_same = 1;
 
                 /* Schedule policy is determined by ->qc_defer()
                  * callback and it needs to see every deferred qc.
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 45a1d71c55f1..fdb180367ba1 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -105,6 +105,7 @@ enum {
         ATA_ID_CFA_KEY_MGMT     = 162,
         ATA_ID_CFA_MODES        = 163,
         ATA_ID_DATA_SET_MGMT    = 169,
+        ATA_ID_SCT_CMD_XPORT    = 206,
         ATA_ID_ROT_SPEED        = 217,
         ATA_ID_PIO4             = (1 << 1),
 
@@ -789,6 +790,48 @@ static inline bool ata_id_sense_reporting_enabled(const u16 *id)
 }
 
 /**
+ *
+ * Word: 206 - SCT Command Transport
+ *    15:12 - Vendor Specific
+ *     11:6 - Reserved
+ *        5 - SCT Command Transport Data Tables supported
+ *        4 - SCT Command Transport Features Control supported
+ *        3 - SCT Command Transport Error Recovery Control supported
+ *        2 - SCT Command Transport Write Same supported
+ *        1 - SCT Command Transport Long Sector Access supported
+ *        0 - SCT Command Transport supported
+ */
+static inline bool ata_id_sct_data_tables(const u16 *id)
+{
+        return id[ATA_ID_SCT_CMD_XPORT] & (1 << 5) ? true : false;
+}
+
+static inline bool ata_id_sct_features_ctrl(const u16 *id)
+{
+        return id[ATA_ID_SCT_CMD_XPORT] & (1 << 4) ? true : false;
+}
+
+static inline bool ata_id_sct_error_recovery_ctrl(const u16 *id)
+{
+        return id[ATA_ID_SCT_CMD_XPORT] & (1 << 3) ? true : false;
+}
+
+static inline bool ata_id_sct_write_same(const u16 *id)
+{
+        return id[ATA_ID_SCT_CMD_XPORT] & (1 << 2) ? true : false;
+}
+
+static inline bool ata_id_sct_long_sector_access(const u16 *id)
+{
+        return id[ATA_ID_SCT_CMD_XPORT] & (1 << 1) ? true : false;
+}
+
+static inline bool ata_id_sct_supported(const u16 *id)
+{
+        return id[ATA_ID_SCT_CMD_XPORT] & (1 << 0) ? true : false;
+}
+
+/**
  *      ata_id_major_version    -       get ATA level of drive
  *      @id: Identify data
  *