[dm-devel] [PATCH 06/12] Add ata pass-through path for ZAC commands.
Shaun Tancheff
shaun at tancheff.com
Mon Apr 4 05:06:10 UTC 2016
The current generation of HBA SAS adapters support connecting SATA
drives and perform SCSI<->ATA translations in hardware.
Unfortunately the ZBC commands are not being translate (yet).
Currently users of SAS controllers can only send ZAC commands via
ata pass-through.
This method overloads the meaning of REQ_META to direct ZBC commands
to construct ZAC equivalent ATA pass through commands.
Note also that this approach expects the initiator to deal with the
little endian result due to bypassing the normal translation layers.
Signed-off-by: Shaun Tancheff <shaun.tancheff at seagate.com>
---
block/ioctl.c | 29 +++++++++++++++++++
drivers/scsi/sd.c | 84 +++++++++++++++++++++++++++++++++++++++++++++----------
2 files changed, 99 insertions(+), 14 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c
index 825848f..aa11450 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -285,6 +285,35 @@ static int blk_zoned_action_ioctl(struct block_device *bdev, fmode_t mode,
return -EFAULT;
}
+ /*
+ * When the low bit is set force ATA passthrough try to work around
+ * older SAS HBA controllers that don't support ZBC to ZAC translation.
+ *
+ * When the low bit is clear follow the normal path but also correct
+ * for ~0ul LBA means 'for all lbas'.
+ *
+ * NB: We should do extra checking here to see if the user specified
+ * the entire block device as opposed to a partition of the
+ * device....
+ */
+ if (arg & 1) {
+ bi_rw |= REQ_META;
+ if (arg != ~0ul)
+ arg &= ~1ul; /* ~1 :: 0xFF...FE */
+ } else {
+ if (arg == ~1ul)
+ arg = ~0ul;
+ }
+
+ /*
+ * When acting on zones we explicitly disallow using a partition.
+ */
+ if (bdev != bdev->bd_contains) {
+ pr_err("%s: All zone operations disallowed on this device\n",
+ __func__);
+ return -EFAULT;
+ }
+
switch (cmd) {
case BLKOPENZONE:
bi_rw |= REQ_OPEN_ZONE;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 379edf6..3cb0200 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -53,6 +53,7 @@
#include <linux/pm_runtime.h>
#include <linux/pr.h>
#include <linux/blkzoned_api.h>
+#include <linux/ata.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
@@ -100,6 +101,16 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
#define SD_MINORS 0
#endif
+static inline void _lba_to_cmd_ata(u8 *cmd, u64 _lba)
+{
+ cmd[1] = _lba & 0xff;
+ cmd[3] = (_lba >> 8) & 0xff;
+ cmd[5] = (_lba >> 16) & 0xff;
+ cmd[0] = (_lba >> 24) & 0xff;
+ cmd[2] = (_lba >> 32) & 0xff;
+ cmd[4] = (_lba >> 40) & 0xff;
+}
+
static void sd_config_discard(struct scsi_disk *, unsigned int);
static void sd_config_write_same(struct scsi_disk *);
static int sd_revalidate_disk(struct gendisk *);
@@ -1181,11 +1192,26 @@ static int sd_setup_zoned_cmnd(struct scsi_cmnd *cmd)
cmd->cmd_len = 16;
memset(cmd->cmnd, 0, cmd->cmd_len);
- cmd->cmnd[0] = ZBC_REPORT_ZONES;
- cmd->cmnd[1] = ZBC_REPORT_OPT;
- put_unaligned_be64(sector, &cmd->cmnd[2]);
- put_unaligned_be32(nr_bytes, &cmd->cmnd[10]);
- cmd->cmnd[14] = bio_get_streamid(bio);
+ if (rq->cmd_flags & REQ_META) {
+ cmd->cmnd[0] = ATA_16;
+ cmd->cmnd[1] = (0x6 << 1) | 1;
+ cmd->cmnd[2] = 0x0e;
+ cmd->cmnd[3] = bio_get_streamid(bio);
+ cmd->cmnd[4] = ATA_SUBCMD_REP_ZONES;
+ cmd->cmnd[5] = ((nr_bytes / 512) >> 8) & 0xff;
+ cmd->cmnd[6] = (nr_bytes / 512) & 0xff;
+
+ _lba_to_cmd_ata(&cmd->cmnd[7], sector);
+
+ cmd->cmnd[13] = 1 << 6;
+ cmd->cmnd[14] = ATA_CMD_ZONE_MAN_IN;
+ } else {
+ cmd->cmnd[0] = ZBC_REPORT_ZONES;
+ cmd->cmnd[1] = ZBC_REPORT_OPT;
+ put_unaligned_be64(sector, &cmd->cmnd[2]);
+ put_unaligned_be32(nr_bytes, &cmd->cmnd[10]);
+ cmd->cmnd[14] = bio_get_streamid(bio);
+ }
cmd->sc_data_direction = DMA_FROM_DEVICE;
cmd->sdb.length = nr_bytes;
cmd->transfersize = sdp->sector_size;
@@ -1207,14 +1233,28 @@ static int sd_setup_zoned_cmnd(struct scsi_cmnd *cmd)
memset(cmd->cmnd, 0, cmd->cmd_len);
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
- cmd->cmnd[0] = ZBC_ACTION;
- cmd->cmnd[1] = ZBC_SA_ZONE_OPEN;
- if (rq->cmd_flags & REQ_CLOSE_ZONE)
- cmd->cmnd[1] = ZBC_SA_ZONE_CLOSE;
- if (rq->cmd_flags & REQ_RESET_ZONE)
- cmd->cmnd[1] = ZBC_SA_RESET_WP;
- cmd->cmnd[14] = allbit;
- put_unaligned_be64(sector, &cmd->cmnd[2]);
+ if (rq->cmd_flags & REQ_META) {
+ cmd->cmnd[0] = ATA_16;
+ cmd->cmnd[1] = (3 << 1) | 1;
+ cmd->cmnd[3] = allbit;
+ cmd->cmnd[4] = ATA_SUBCMD_OPEN_ZONES;
+ if (rq->cmd_flags & REQ_CLOSE_ZONE)
+ cmd->cmnd[4] = ATA_SUBCMD_CLOSE_ZONES;
+ if (rq->cmd_flags & REQ_RESET_ZONE)
+ cmd->cmnd[4] = ATA_SUBCMD_RESET_WP;
+ _lba_to_cmd_ata(&cmd->cmnd[7], sector);
+ cmd->cmnd[13] = 1 << 6;
+ cmd->cmnd[14] = ATA_CMD_ZONE_MAN_OUT;
+ } else {
+ cmd->cmnd[0] = ZBC_ACTION;
+ cmd->cmnd[1] = ZBC_SA_ZONE_OPEN;
+ if (rq->cmd_flags & REQ_CLOSE_ZONE)
+ cmd->cmnd[1] = ZBC_SA_ZONE_CLOSE;
+ if (rq->cmd_flags & REQ_RESET_ZONE)
+ cmd->cmnd[1] = ZBC_SA_RESET_WP;
+ cmd->cmnd[14] = allbit;
+ put_unaligned_be64(sector, &cmd->cmnd[2]);
+ }
cmd->transfersize = 0;
cmd->underflow = 0;
cmd->allowed = SD_MAX_RETRIES;
@@ -2812,7 +2852,7 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
{
unsigned char *buffer;
u16 rot;
- const int vpd_len = 64;
+ const int vpd_len = 512;
buffer = kmalloc(vpd_len, GFP_KERNEL);
@@ -2839,6 +2879,22 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
* Any subsequent reads will be zero'd.
*/
sdkp->device->zabc = 1;
+ } else {
+ unsigned char cmd[16] = { 0 };
+
+ cmd[0] = ATA_16;
+ cmd[1] = (4 << 1) | 1;
+ cmd[2] = 0xe;
+ cmd[6] = 0x1;
+ cmd[8] = 0x1;
+ cmd[14] = ATA_CMD_ID_ATA;
+
+ if (scsi_execute_req(sdkp->device, cmd, DMA_FROM_DEVICE, buffer,
+ vpd_len, NULL, 30 * HZ, 3, NULL))
+ goto out;
+
+ if (ata_drive_zac_ha((u16 *)buffer))
+ sdkp->device->zabc = 1;
}
out:
--
1.9.1
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