1 files changed, 349 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_common.c b/drivers/scsi/scsi_common.c
new file mode 100644
index 000000000..90349498f
--- /dev/null
+++ b/drivers/scsi/scsi_common.c
@@ -0,0 +1,349 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SCSI functions used by both the initiator and the target code.
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <asm/unaligned.h>
+#include <scsi/scsi_common.h>
+
+/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
+ * You may not alter any existing entry (although adding new ones is
+ * encouraged once assigned by ANSI/INCITS T10).
+ */
+static const char *const scsi_device_types[] = {
+	"Direct-Access    ",
+	"Sequential-Access",
+	"Printer          ",
+	"Processor        ",
+	"WORM             ",
+	"CD-ROM           ",
+	"Scanner          ",
+	"Optical Device   ",
+	"Medium Changer   ",
+	"Communications   ",
+	"ASC IT8          ",
+	"ASC IT8          ",
+	"RAID             ",
+	"Enclosure        ",
+	"Direct-Access-RBC",
+	"Optical card     ",
+	"Bridge controller",
+	"Object storage   ",
+	"Automation/Drive ",
+	"Security Manager ",
+	"Direct-Access-ZBC",
+};
+
+/**
+ * scsi_device_type - Return 17-char string indicating device type.
+ * @type: type number to look up
+ */
+const char *scsi_device_type(unsigned type)
+{
+	if (type == 0x1e)
+		return "Well-known LUN   ";
+	if (type == 0x1f)
+		return "No Device        ";
+	if (type >= ARRAY_SIZE(scsi_device_types))
+		return "Unknown          ";
+	return scsi_device_types[type];
+}
+EXPORT_SYMBOL(scsi_device_type);
+
+/**
+ * scsilun_to_int - convert a scsi_lun to an int
+ * @scsilun:	struct scsi_lun to be converted.
+ *
+ * Description:
+ *     Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
+ *     integer, and return the result. The caller must check for
+ *     truncation before using this function.
+ *
+ * Notes:
+ *     For a description of the LUN format, post SCSI-3 see the SCSI
+ *     Architecture Model, for SCSI-3 see the SCSI Controller Commands.
+ *
+ *     Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
+ *     returns the integer: 0x0b03d204
+ *
+ *     This encoding will return a standard integer LUN for LUNs smaller
+ *     than 256, which typically use a single level LUN structure with
+ *     addressing method 0.
+ */
+u64 scsilun_to_int(struct scsi_lun *scsilun)
+{
+	int i;
+	u64 lun;
+
+	lun = 0;
+	for (i = 0; i < sizeof(lun); i += 2)
+		lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
+			     ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
+	return lun;
+}
+EXPORT_SYMBOL(scsilun_to_int);
+
+/**
+ * int_to_scsilun - reverts an int into a scsi_lun
+ * @lun:        integer to be reverted
+ * @scsilun:	struct scsi_lun to be set.
+ *
+ * Description:
+ *     Reverts the functionality of the scsilun_to_int, which packed
+ *     an 8-byte lun value into an int. This routine unpacks the int
+ *     back into the lun value.
+ *
+ * Notes:
+ *     Given an integer : 0x0b03d204, this function returns a
+ *     struct scsi_lun of: d2 04 0b 03 00 00 00 00
+ *
+ */
+void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
+{
+	int i;
+
+	memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
+
+	for (i = 0; i < sizeof(lun); i += 2) {
+		scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
+		scsilun->scsi_lun[i+1] = lun & 0xFF;
+		lun = lun >> 16;
+	}
+}
+EXPORT_SYMBOL(int_to_scsilun);
+
+/**
+ * scsi_normalize_sense - normalize main elements from either fixed or
+ *			descriptor sense data format into a common format.
+ *
+ * @sense_buffer:	byte array containing sense data returned by device
+ * @sb_len:		number of valid bytes in sense_buffer
+ * @sshdr:		pointer to instance of structure that common
+ *			elements are written to.
+ *
+ * Notes:
+ *	The "main elements" from sense data are: response_code, sense_key,
+ *	asc, ascq and additional_length (only for descriptor format).
+ *
+ *	Typically this function can be called after a device has
+ *	responded to a SCSI command with the CHECK_CONDITION status.
+ *
+ * Return value:
+ *	true if valid sense data information found, else false;
+ */
+bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
+			  struct scsi_sense_hdr *sshdr)
+{
+	memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
+
+	if (!sense_buffer || !sb_len)
+		return false;
+
+	sshdr->response_code = (sense_buffer[0] & 0x7f);
+
+	if (!scsi_sense_valid(sshdr))
+		return false;
+
+	if (sshdr->response_code >= 0x72) {
+		/*
+		 * descriptor format
+		 */
+		if (sb_len > 1)
+			sshdr->sense_key = (sense_buffer[1] & 0xf);
+		if (sb_len > 2)
+			sshdr->asc = sense_buffer[2];
+		if (sb_len > 3)
+			sshdr->ascq = sense_buffer[3];
+		if (sb_len > 7)
+			sshdr->additional_length = sense_buffer[7];
+	} else {
+		/*
+		 * fixed format
+		 */
+		if (sb_len > 2)
+			sshdr->sense_key = (sense_buffer[2] & 0xf);
+		if (sb_len > 7) {
+			sb_len = (sb_len < (sense_buffer[7] + 8)) ?
+					 sb_len : (sense_buffer[7] + 8);
+			if (sb_len > 12)
+				sshdr->asc = sense_buffer[12];
+			if (sb_len > 13)
+				sshdr->ascq = sense_buffer[13];
+		}
+	}
+
+	return true;
+}
+EXPORT_SYMBOL(scsi_normalize_sense);
+
+/**
+ * scsi_sense_desc_find - search for a given descriptor type in	descriptor sense data format.
+ * @sense_buffer:	byte array of descriptor format sense data
+ * @sb_len:		number of valid bytes in sense_buffer
+ * @desc_type:		value of descriptor type to find
+ *			(e.g. 0 -> information)
+ *
+ * Notes:
+ *	only valid when sense data is in descriptor format
+ *
+ * Return value:
+ *	pointer to start of (first) descriptor if found else NULL
+ */
+const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
+				int desc_type)
+{
+	int add_sen_len, add_len, desc_len, k;
+	const u8 * descp;
+
+	if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
+		return NULL;
+	if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
+		return NULL;
+	add_sen_len = (add_sen_len < (sb_len - 8)) ?
+			add_sen_len : (sb_len - 8);
+	descp = &sense_buffer[8];
+	for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
+		descp += desc_len;
+		add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
+		desc_len = add_len + 2;
+		if (descp[0] == desc_type)
+			return descp;
+		if (add_len < 0) // short descriptor ??
+			break;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(scsi_sense_desc_find);
+
+/**
+ * scsi_build_sense_buffer - build sense data in a buffer
+ * @desc:	Sense format (non-zero == descriptor format,
+ *              0 == fixed format)
+ * @buf:	Where to build sense data
+ * @key:	Sense key
+ * @asc:	Additional sense code
+ * @ascq:	Additional sense code qualifier
+ *
+ **/
+void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
+{
+	if (desc) {
+		buf[0] = 0x72;	/* descriptor, current */
+		buf[1] = key;
+		buf[2] = asc;
+		buf[3] = ascq;
+		buf[7] = 0;
+	} else {
+		buf[0] = 0x70;	/* fixed, current */
+		buf[2] = key;
+		buf[7] = 0xa;
+		buf[12] = asc;
+		buf[13] = ascq;
+	}
+}
+EXPORT_SYMBOL(scsi_build_sense_buffer);
+
+/**
+ * scsi_set_sense_information - set the information field in a
+ *		formatted sense data buffer
+ * @buf:	Where to build sense data
+ * @buf_len:    buffer length
+ * @info:	64-bit information value to be set
+ *
+ * Return value:
+ *	0 on success or -EINVAL for invalid sense buffer length
+ **/
+int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
+{
+	if ((buf[0] & 0x7f) == 0x72) {
+		u8 *ucp, len;
+
+		len = buf[7];
+		ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
+		if (!ucp) {
+			buf[7] = len + 0xc;
+			ucp = buf + 8 + len;
+		}
+
+		if (buf_len < len + 0xc)
+			/* Not enough room for info */
+			return -EINVAL;
+
+		ucp[0] = 0;
+		ucp[1] = 0xa;
+		ucp[2] = 0x80; /* Valid bit */
+		ucp[3] = 0;
+		put_unaligned_be64(info, &ucp[4]);
+	} else if ((buf[0] & 0x7f) == 0x70) {
+		/*
+		 * Only set the 'VALID' bit if we can represent the value
+		 * correctly; otherwise just fill out the lower bytes and
+		 * clear the 'VALID' flag.
+		 */
+		if (info <= 0xffffffffUL)
+			buf[0] |= 0x80;
+		else
+			buf[0] &= 0x7f;
+		put_unaligned_be32((u32)info, &buf[3]);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(scsi_set_sense_information);
+
+/**
+ * scsi_set_sense_field_pointer - set the field pointer sense key
+ *		specific information in a formatted sense data buffer
+ * @buf:	Where to build sense data
+ * @buf_len:    buffer length
+ * @fp:		field pointer to be set
+ * @bp:		bit pointer to be set
+ * @cd:		command/data bit
+ *
+ * Return value:
+ *	0 on success or -EINVAL for invalid sense buffer length
+ */
+int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
+{
+	u8 *ucp, len;
+
+	if ((buf[0] & 0x7f) == 0x72) {
+		len = buf[7];
+		ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
+		if (!ucp) {
+			buf[7] = len + 8;
+			ucp = buf + 8 + len;
+		}
+
+		if (buf_len < len + 8)
+			/* Not enough room for info */
+			return -EINVAL;
+
+		ucp[0] = 2;
+		ucp[1] = 6;
+		ucp[4] = 0x80; /* Valid bit */
+		if (cd)
+			ucp[4] |= 0x40;
+		if (bp < 0x8)
+			ucp[4] |= 0x8 | bp;
+		put_unaligned_be16(fp, &ucp[5]);
+	} else if ((buf[0] & 0x7f) == 0x70) {
+		len = buf[7];
+		if (len < 18)
+			buf[7] = 18;
+
+		buf[15] = 0x80;
+		if (cd)
+			buf[15] |= 0x40;
+		if (bp < 0x8)
+			buf[15] |= 0x8 | bp;
+		put_unaligned_be16(fp, &buf[16]);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(scsi_set_sense_field_pointer);