summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/scsi/scsi_common.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/drivers/scsi/scsi_common.c')
-rw-r--r--kernel/drivers/scsi/scsi_common.c287
1 files changed, 287 insertions, 0 deletions
diff --git a/kernel/drivers/scsi/scsi_common.c b/kernel/drivers/scsi/scsi_common.c
new file mode 100644
index 000000000..c12696613
--- /dev/null
+++ b/kernel/drivers/scsi/scsi_common.c
@@ -0,0 +1,287 @@
+/*
+ * 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)
+{
+ if (!sense_buffer || !sb_len)
+ return false;
+
+ memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
+
+ 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) {
+ buf[0] |= 0x80;
+ put_unaligned_be64(info, &buf[3]);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(scsi_set_sense_information);