sed-opal: geometry feature reporting command

Locking range start and locking range length
attributes may be require to satisfy restrictions
exposed by OPAL2 geometry feature reporting.

Geometry reporting feature is described in TCG OPAL SSC,
section 3.1.1.4 (ALIGN, LogicalBlockSize, AlignmentGranularity
and LowestAlignedLBA).

4.3.5.2.1.1 RangeStart Behavior:

[ StartAlignment = (RangeStart modulo AlignmentGranularity) - LowestAlignedLBA ]

When processing a Set method or CreateRow method on the Locking
table for a non-Global Range row, if:

a) the AlignmentRequired (ALIGN above) column in the LockingInfo
table is TRUE;
b) RangeStart is non-zero; and
c) StartAlignment is non-zero, then the method SHALL fail and
return an error status code INVALID_PARAMETER.

4.3.5.2.1.2 RangeLength Behavior:

If RangeStart is zero, then
[ LengthAlignment = (RangeLength modulo AlignmentGranularity) - LowestAlignedLBA ]

If RangeStart is non-zero, then
[ LengthAlignment = (RangeLength modulo AlignmentGranularity) ]

When processing a Set method or CreateRow method on the Locking
table for a non-Global Range row, if:

a) the AlignmentRequired (ALIGN above) column in the LockingInfo
table is TRUE;
b) RangeLength is non-zero; and
c) LengthAlignment is non-zero, then the method SHALL fail and
return an error status code INVALID_PARAMETER

In userspace we stuck to logical block size reported by general
block device (via sysfs or ioctl), but we can not read
'AlignmentGranularity' or 'LowestAlignedLBA' anywhere else and
we need to get those values from sed-opal interface otherwise
we will not be able to report or avoid locking range setup
INVALID_PARAMETER errors above.

Signed-off-by: Ondrej Kozina <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Christian Brauner <[e-mail]>
Tested-by: Milan Broz <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jens Axboe <[e-mail]>

block/sed-opal.c

···
 	u16 comid;
 	u32 hsn;
 	u32 tsn;
-	u64 align;
+	u64 align; /* alignment granularity */
 	u64 lowest_lba;
+	u32 logical_block_size;
+	u8  align_required; /* ALIGN: 0 or 1 */
 
 	size_t pos;
 	u8 *cmd;
···
 
 	dev->align = be64_to_cpu(geo->alignment_granularity);
 	dev->lowest_lba = be64_to_cpu(geo->lowest_aligned_lba);
+	dev->logical_block_size = be32_to_cpu(geo->logical_block_size);
+	dev->align_required = geo->reserved01 & 1;
 }
 
 static int execute_step(struct opal_dev *dev,
···
 	return 0;
 }
 
+static int opal_get_geometry(struct opal_dev *dev, void __user *data)
+{
+	struct opal_geometry geo = {0};
+
+	if (check_opal_support(dev))
+		return -EINVAL;
+
+	geo.align = dev->align_required;
+	geo.logical_block_size = dev->logical_block_size;
+	geo.alignment_granularity =  dev->align;
+	geo.lowest_aligned_lba = dev->lowest_lba;
+
+	if (copy_to_user(data, &geo, sizeof(geo))) {
+		pr_debug("Error copying geometry data to userspace\n");
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
 int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
 {
 	void *p;
···
 		break;
 	case IOC_OPAL_GET_LR_STATUS:
 		ret = opal_locking_range_status(dev, p, arg);
+		break;
+	case IOC_OPAL_GET_GEOMETRY:
+		ret = opal_get_geometry(dev, arg);
 		break;
 	default:
 		break;

include/linux/sed-opal.h

···
 	case IOC_OPAL_GENERIC_TABLE_RW:
 	case IOC_OPAL_GET_STATUS:
 	case IOC_OPAL_GET_LR_STATUS:
+	case IOC_OPAL_GET_GEOMETRY:
 		return true;
 	}
 	return false;

include/uapi/linux/sed-opal.h

···
 	__u32 reserved;
 };
 
+/*
+ * Geometry Reporting per TCG Storage OPAL SSC
+ * section 3.1.1.4
+ */
+struct opal_geometry {
+	__u8 align;
+	__u32 logical_block_size;
+	__u64 alignment_granularity;
+	__u64 lowest_aligned_lba;
+	__u8  __align[3];
+};
+
 #define IOC_OPAL_SAVE		    _IOW('p', 220, struct opal_lock_unlock)
 #define IOC_OPAL_LOCK_UNLOCK	    _IOW('p', 221, struct opal_lock_unlock)
 #define IOC_OPAL_TAKE_OWNERSHIP	    _IOW('p', 222, struct opal_key)
···
 #define IOC_OPAL_GENERIC_TABLE_RW   _IOW('p', 235, struct opal_read_write_table)
 #define IOC_OPAL_GET_STATUS         _IOR('p', 236, struct opal_status)
 #define IOC_OPAL_GET_LR_STATUS      _IOW('p', 237, struct opal_lr_status)
+#define IOC_OPAL_GET_GEOMETRY       _IOR('p', 238, struct opal_geometry)
 
 #endif /* _UAPI_SED_OPAL_H */