libata: Expose TRIM capability in sysfs

Create a sysfs "trim" attribute for each ata_device that displays whether DSM TRIM is "unsupported", "unqueued", "forced_unqueued" (blacklisted) or "queued". Signed-off-by: Martin K. Petersen <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Signed-off-by: Tejun Heo <[email protected]>
modi0012 · May 5, 2015 · f303074 · f303074
1 parent d7b16e4
commit f303074
Show file tree

Hide file tree

Showing 2 changed files with 33 additions and 0 deletions.
diff --git a/Documentation/ABI/testing/sysfs-ata b/Documentation/ABI/testing/sysfs-ata
@@ -90,6 +90,17 @@ gscr
 	130:	SATA_PMP_GSCR_SII_GPIO
 	Only valid if the device is a PM.
 
+trim
+
+	Shows the DSM TRIM mode currently used by the device. Valid
+	values are:
+	unsupported:		Drive does not support DSM TRIM
+	unqueued:		Drive supports unqueued DSM TRIM only
+	queued:			Drive supports queued DSM TRIM
+	forced_unqueued:	Drive's unqueued DSM support is known to be
+				buggy and only unqueued TRIM commands
+				are sent
+
 spdn_cnt
 
 	Number of time libata decided to lower the speed of link due to errors.

diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c
@@ -560,6 +560,27 @@ show_ata_dev_gscr(struct device *dev,
 
 static DEVICE_ATTR(gscr, S_IRUGO, show_ata_dev_gscr, NULL);
 
+static ssize_t
+show_ata_dev_trim(struct device *dev,
+		  struct device_attribute *attr, char *buf)
+{
+	struct ata_device *ata_dev = transport_class_to_dev(dev);
+	unsigned char *mode;
+
+	if (!ata_id_has_trim(ata_dev->id))
+		mode = "unsupported";
+	else if (ata_dev->horkage & ATA_HORKAGE_NO_NCQ_TRIM)
+			mode = "forced_unqueued";
+	else if (ata_fpdma_dsm_supported(ata_dev))
+		mode = "queued";
+	else
+		mode = "unqueued";
+
+	return snprintf(buf, 20, "%s\n", mode);
+}
+
+static DEVICE_ATTR(trim, S_IRUGO, show_ata_dev_trim, NULL);
+
 static DECLARE_TRANSPORT_CLASS(ata_dev_class,
 			       "ata_device", NULL, NULL, NULL);
 
@@ -733,6 +754,7 @@ struct scsi_transport_template *ata_attach_transport(void)
 	SETUP_DEV_ATTRIBUTE(ering);
 	SETUP_DEV_ATTRIBUTE(id);
 	SETUP_DEV_ATTRIBUTE(gscr);
+	SETUP_DEV_ATTRIBUTE(trim);
 	BUG_ON(count > ATA_DEV_ATTRS);
 	i->dev_attrs[count] = NULL;