Add initial support for UNMAP granularity.

Report UNMAP granularity as stripesize/-offset if we have no other values
to report there.

Add new quirk DA_Q_STRICT_UNMAP for cases when target is too critical to
misaligned UNMAP request, reporting errors instead of being suboptimal.
Setting this quirk makes da periph to forcefully align all UNMAP requests
to avoid those errors by the cost of some odd ranges not being UNMAP'ed.
This makes UNMAP usable within VMware 6.x VMs, just now 100% efficient.

MFC after:	2 weeks

1 files changed, 71 insertions, 13 deletions

diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c
index 55f2386262a2..b8f2802a0e05 100644
--- a/sys/cam/scsi/scsi_da.c
+++ b/sys/cam/scsi/scsi_da.c
@@ -123,7 +123,8 @@ typedef enum {
 	DA_Q_NO_RC16		= 0x10,
 	DA_Q_NO_UNMAP		= 0x20,
 	DA_Q_RETRY_BUSY		= 0x40,
-	DA_Q_SMR_DM		= 0x80
+	DA_Q_SMR_DM		= 0x80,
+	DA_Q_STRICT_UNMAP	= 0x100
 } da_quirks;
 
 #define DA_Q_BIT_STRING		\
@@ -135,7 +136,8 @@ typedef enum {
 	"\005NO_RC16"		\
 	"\006NO_UNMAP"		\
 	"\007RETRY_BUSY"	\
-	"\008SMR_DM"
+	"\010SMR_DM"		\
+	"\011STRICT_UNMAP"
 
 typedef enum {
 	DA_CCB_PROBE_RC		= 0x01,
@@ -310,6 +312,8 @@ struct da_softc {
 	u_int	 		maxio;
 	uint32_t		unmap_max_ranges;
 	uint32_t		unmap_max_lba; /* Max LBAs in UNMAP req */
+	uint32_t		unmap_gran;
+	uint32_t		unmap_gran_align;
 	uint64_t		ws_max_blks;
 	da_delete_methods	delete_method_pref;
 	da_delete_methods	delete_method;
@@ -468,9 +472,10 @@ static struct da_quirk_entry da_quirk_table[] =
 		/*
 		 * VMware returns BUSY status when storage has transient
 		 * connectivity problems, so better wait.
+		 * Also VMware returns odd errors on misaligned UNMAPs.
 		 */
 		{T_DIRECT, SIP_MEDIA_FIXED, "VMware*", "*", "*"},
-		/*quirks*/ DA_Q_RETRY_BUSY
+		/*quirks*/ DA_Q_RETRY_BUSY | DA_Q_STRICT_UNMAP
 	},
 	/* USB mass storage devices supported by umass(4) */
 	{
@@ -2408,6 +2413,8 @@ daregister(struct cam_periph *periph, void *arg)
 		softc->flags |= DA_FLAG_PACK_REMOVABLE;
 	softc->unmap_max_ranges = UNMAP_MAX_RANGES;
 	softc->unmap_max_lba = UNMAP_RANGE_MAX;
+	softc->unmap_gran = 0;
+	softc->unmap_gran_align = 0;
 	softc->ws_max_blks = WS16_MAX_BLKS;
 	softc->trim_max_ranges = ATA_TRIM_MAX_RANGES;
 	softc->rotating = 1;
@@ -3522,11 +3529,11 @@ da_delete_unmap(struct cam_periph *periph, union ccb *ccb, struct bio *bp)
 	struct da_softc *softc = (struct da_softc *)periph->softc;;
 	struct bio *bp1;
 	uint8_t *buf = softc->unmap_buf;
+	struct scsi_unmap_desc *d = (void *)&buf[UNMAP_HEAD_SIZE];
 	uint64_t lba, lastlba = (uint64_t)-1;
 	uint64_t totalcount = 0;
 	uint64_t count;
-	uint32_t lastcount = 0, c;
-	uint32_t off, ranges = 0;
+	uint32_t c, lastcount = 0, ranges = 0;
 
 	/*
 	 * Currently this doesn't take the UNMAP
@@ -3559,13 +3566,39 @@ da_delete_unmap(struct cam_periph *periph, union ccb *ccb, struct bio *bp)
 		/* Try to extend the previous range. */
 		if (lba == lastlba) {
 			c = omin(count, UNMAP_RANGE_MAX - lastcount);
+			lastlba += c;
 			lastcount += c;
-			off = ((ranges - 1) * UNMAP_RANGE_SIZE) +
-			      UNMAP_HEAD_SIZE;
-			scsi_ulto4b(lastcount, &buf[off + 8]);
+			scsi_ulto4b(lastcount, d[ranges - 1].length);
 			count -= c;
-			lba +=c;
+			lba += c;
 			totalcount += c;
+		} else if ((softc->quirks & DA_Q_STRICT_UNMAP) &&
+		    softc->unmap_gran != 0) {
+			/* Align length of the previous range. */
+			if ((c = lastcount % softc->unmap_gran) != 0) {
+				if (lastcount <= c) {
+					totalcount -= lastcount;
+					lastlba = (uint64_t)-1;
+					lastcount = 0;
+					ranges--;
+				} else {
+					totalcount -= c;
+					lastlba -= c;
+					lastcount -= c;
+					scsi_ulto4b(lastcount, d[ranges - 1].length);
+				}
+			}
+			/* Align beginning of the new range. */
+			c = (lba - softc->unmap_gran_align) % softc->unmap_gran;
+			if (c != 0) {
+				c = softc->unmap_gran - c;
+				if (count <= c) {
+					count = 0;
+				} else {
+					lba += c;
+					count -= c;
+				}
+			}
 		}
 
 		while (count > 0) {
@@ -3580,16 +3613,15 @@ da_delete_unmap(struct cam_periph *periph, union ccb *ccb, struct bio *bp)
 				    ranges, softc->unmap_max_ranges);
 				break;
 			}
-			off = (ranges * UNMAP_RANGE_SIZE) + UNMAP_HEAD_SIZE;
-			scsi_u64to8b(lba, &buf[off + 0]);
-			scsi_ulto4b(c, &buf[off + 8]);
+			scsi_u64to8b(lba, d[ranges].lba);
+			scsi_ulto4b(c, d[ranges].length);
 			lba += c;
 			totalcount += c;
 			ranges++;
 			count -= c;
+			lastlba = lba;
 			lastcount = c;
 		}
-		lastlba = lba;
 		bp1 = cam_iosched_next_trim(softc->cam_iosched);
 		if (bp1 == NULL)
 			break;
@@ -3600,6 +3632,16 @@ da_delete_unmap(struct cam_periph *periph, union ccb *ccb, struct bio *bp)
 			break;
 		}
 	} while (1);
+
+	/* Align length of the last range. */
+	if ((softc->quirks & DA_Q_STRICT_UNMAP) && softc->unmap_gran != 0 &&
+	    (c = lastcount % softc->unmap_gran) != 0) {
+		if (lastcount <= c)
+			ranges--;
+		else
+			scsi_ulto4b(lastcount - c, d[ranges - 1].length);
+	}
+
 	scsi_ulto2b(ranges * 16 + 6, &buf[0]);
 	scsi_ulto2b(ranges * 16, &buf[2]);
 
@@ -4483,6 +4525,10 @@ dadone(struct cam_periph *periph, union ccb *done_ccb)
 				block_limits->max_unmap_lba_cnt);
 			uint32_t max_unmap_blk_cnt = scsi_4btoul(
 				block_limits->max_unmap_blk_cnt);
+			uint32_t unmap_gran = scsi_4btoul(
+				block_limits->opt_unmap_grain);
+			uint32_t unmap_gran_align = scsi_4btoul(
+				block_limits->unmap_grain_align);
 			uint64_t ws_max_blks = scsi_8btou64(
 				block_limits->max_write_same_length);
 
@@ -4500,6 +4546,14 @@ dadone(struct cam_periph *periph, union ccb *done_ccb)
 				softc->unmap_max_lba = max_unmap_lba_cnt;
 				softc->unmap_max_ranges = min(max_unmap_blk_cnt,
 					UNMAP_MAX_RANGES);
+				if (unmap_gran > 1) {
+					softc->unmap_gran = unmap_gran;
+					if (unmap_gran_align & 0x80000000) {
+						softc->unmap_gran_align =
+						    unmap_gran_align &
+						    0x7fffffff;
+					}
+				}
 			} else {
 				/*
 				 * Unexpected UNMAP limits which means the
@@ -5414,6 +5468,10 @@ dasetgeom(struct cam_periph *periph, uint32_t block_len, uint64_t maxsector,
 	} else if (softc->quirks & DA_Q_4K) {
 		dp->stripesize = 4096;
 		dp->stripeoffset = 0;
+	} else if (softc->unmap_gran != 0) {
+		dp->stripesize = block_len * softc->unmap_gran;
+		dp->stripeoffset = (dp->stripesize - block_len *
+		    softc->unmap_gran_align) % dp->stripesize;
 	} else {
 		dp->stripesize = 0;
 		dp->stripeoffset = 0;