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path: root/drivers/scsi/scsi_common.c
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Diffstat (limited to 'drivers/scsi/scsi_common.c')
-rw-r--r--drivers/scsi/scsi_common.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_common.c b/drivers/scsi/scsi_common.c
index 2ff092252b76..c126966130ab 100644
--- a/drivers/scsi/scsi_common.c
+++ b/drivers/scsi/scsi_common.c
@@ -5,6 +5,8 @@
#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.
@@ -176,3 +178,110 @@ bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
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);