[PATCH] iscsi endianness annotations

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 49 insertions, 43 deletions

diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
index 0a7d1ab60e6d..89e37283c836 100644
--- a/drivers/infiniband/ulp/iser/iser_initiator.c
+++ b/drivers/infiniband/ulp/iser/iser_initiator.c
@@ -567,7 +567,7 @@ void iser_rcv_completion(struct iser_desc *rx_desc,
         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 
         if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
-                itt = hdr->itt & ISCSI_ITT_MASK; /* mask out cid and age bits */
+                itt = get_itt(hdr->itt); /* mask out cid and age bits */
                 if (!(itt < session->cmds_max))
                         iser_err("itt can't be matched to task!!!"
                                  "conn %p opcode %d cmds_max %d itt %d\n",
@@ -625,7 +625,7 @@ void iser_snd_completion(struct iser_desc *tx_desc)
                 /* this arithmetic is legal by libiscsi dd_data allocation */
                 mtask = (void *) ((long)(void *)tx_desc -
                                   sizeof(struct iscsi_mgmt_task));
-                if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
+                if (mtask->hdr->itt == RESERVED_ITT) {
                         struct iscsi_session *session = conn->session;
 
                         spin_lock(&conn->session->lock);
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 437684084377..8f55e1431433 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -1375,7 +1375,7 @@ iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
         }
 
         BUG_ON(tcp_mtask->xmstate != XMSTATE_IDLE);
-        if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
+        if (mtask->hdr->itt == RESERVED_ITT) {
                 struct iscsi_session *session = conn->session;
 
                 spin_lock_bh(&session->lock);
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index d37048c96eab..7c75771c77ff 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -113,8 +113,7 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
         hdr->opcode = ISCSI_OP_SCSI_CMD;
         hdr->flags = ISCSI_ATTR_SIMPLE;
         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
-        hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) |
-                         (session->age << ISCSI_AGE_SHIFT);
+        hdr->itt = build_itt(ctask->itt, conn->id, session->age);
         hdr->data_length = cpu_to_be32(sc->request_bufflen);
         hdr->cmdsn = cpu_to_be32(session->cmdsn);
         session->cmdsn++;
@@ -270,7 +269,7 @@ invalid_datalen:
                         goto out;
                 }
 
-                senselen = be16_to_cpu(*(uint16_t *)data);
+                senselen = be16_to_cpu(*(__be16 *)data);
                 if (datalen < senselen)
                         goto invalid_datalen;
 
@@ -338,7 +337,7 @@ static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 
                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
-                        itt = rejected_pdu.itt & ISCSI_ITT_MASK;
+                        itt = get_itt(rejected_pdu.itt);
                         printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
                                 "due to DataDigest error.\n", itt,
                                 rejected_pdu.opcode);
@@ -367,10 +366,10 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
         struct iscsi_mgmt_task *mtask;
         uint32_t itt;
 
-        if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
-                itt = hdr->itt & ISCSI_ITT_MASK;
+        if (hdr->itt != RESERVED_ITT)
+                itt = get_itt(hdr->itt);
         else
-                itt = hdr->itt;
+                itt = ~0U;
 
         if (itt < session->cmds_max) {
                 ctask = session->cmds[itt];
@@ -440,7 +439,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
                         iscsi_tmf_rsp(conn, hdr);
                         break;
                 case ISCSI_OP_NOOP_IN:
-                        if (hdr->ttt != ISCSI_RESERVED_TAG || datalen) {
+                        if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
                                 rc = ISCSI_ERR_PROTO;
                                 break;
                         }
@@ -457,7 +456,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
                         rc = ISCSI_ERR_BAD_OPCODE;
                         break;
                 }
-        } else if (itt == ISCSI_RESERVED_TAG) {
+        } else if (itt == ~0U) {
                 rc = iscsi_check_assign_cmdsn(session,
                                              (struct iscsi_nopin*)hdr);
                 if (rc)
@@ -470,7 +469,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
                                 break;
                         }
 
-                        if (hdr->ttt == ISCSI_RESERVED_TAG)
+                        if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
                                 break;
 
                         if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
@@ -516,24 +515,24 @@ int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
         struct iscsi_cmd_task *ctask;
         uint32_t itt;
 
-        if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
-                if ((hdr->itt & ISCSI_AGE_MASK) !=
+        if (hdr->itt != RESERVED_ITT) {
+                if (((__force u32)hdr->itt & ISCSI_AGE_MASK) !=
                     (session->age << ISCSI_AGE_SHIFT)) {
                         printk(KERN_ERR "iscsi: received itt %x expected "
-                                "session age (%x)\n", hdr->itt,
+                                "session age (%x)\n", (__force u32)hdr->itt,
                                 session->age & ISCSI_AGE_MASK);
                         return ISCSI_ERR_BAD_ITT;
                 }
 
-                if ((hdr->itt & ISCSI_CID_MASK) !=
+                if (((__force u32)hdr->itt & ISCSI_CID_MASK) !=
                     (conn->id << ISCSI_CID_SHIFT)) {
                         printk(KERN_ERR "iscsi: received itt %x, expected "
-                                "CID (%x)\n", hdr->itt, conn->id);
+                                "CID (%x)\n", (__force u32)hdr->itt, conn->id);
                         return ISCSI_ERR_BAD_ITT;
                 }
-                itt = hdr->itt & ISCSI_ITT_MASK;
+                itt = get_itt(hdr->itt);
         } else
-                itt = hdr->itt;
+                itt = ~0U;
 
         if (itt < session->cmds_max) {
                 ctask = session->cmds[itt];
@@ -896,9 +895,8 @@ iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
         /*
          * pre-format CmdSN for outgoing PDU.
          */
-        if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
-                hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
-                           (session->age << ISCSI_AGE_SHIFT);
+        if (hdr->itt != RESERVED_ITT) {
+                hdr->itt = build_itt(mtask->itt, conn->id, session->age);
                 nop->cmdsn = cpu_to_be32(session->cmdsn);
                 if (conn->c_stage == ISCSI_CONN_STARTED &&
                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
@@ -1064,7 +1062,7 @@ static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
 
         spin_lock_bh(&session->lock);
         ctask->mtask = (struct iscsi_mgmt_task *)
-                        session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
+                        session->mgmt_cmds[get_itt(hdr->itt) -
                                         ISCSI_MGMT_ITT_OFFSET];
 
         if (conn->tmabort_state == TMABORT_INITIAL) {
diff --git a/include/scsi/iscsi_proto.h b/include/scsi/iscsi_proto.h
index 02f6e4b9e693..4a44278ed768 100644
--- a/include/scsi/iscsi_proto.h
+++ b/include/scsi/iscsi_proto.h
@@ -40,6 +40,14 @@
 }
 #define zero_data(p) {p[0]=0;p[1]=0;p[2]=0;}
 
+/* initiator tags; opaque for target */
+typedef uint32_t __bitwise__ itt_t;
+/* below makes sense only for initiator that created this tag */
+#define build_itt(itt, id, age) ((__force itt_t)\
+        ((itt) | ((id) << ISCSI_CID_SHIFT) | ((age) << ISCSI_AGE_SHIFT)))
+#define get_itt(itt) ((__force uint32_t)(itt_t)(itt) & ISCSI_ITT_MASK)
+#define RESERVED_ITT ((__force itt_t)0xffffffff)
+
 /*
  * iSCSI Template Message Header
  */
@@ -50,7 +58,7 @@ struct iscsi_hdr {
         uint8_t         hlength;        /* AHSs total length */
         uint8_t         dlength[3];     /* Data length */
         uint8_t         lun[8];
-        __be32          itt;            /* Initiator Task Tag */
+        itt_t           itt;            /* Initiator Task Tag, opaque for target */
         __be32          ttt;            /* Target Task Tag */
         __be32          statsn;
         __be32          exp_statsn;
@@ -111,7 +119,7 @@ struct iscsi_cmd {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t lun[8];
-        __be32 itt;     /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be32 data_length;
         __be32 cmdsn;
         __be32 exp_statsn;
@@ -148,7 +156,7 @@ struct iscsi_cmd_rsp {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t rsvd[8];
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be32  rsvd1;
         __be32  statsn;
         __be32  exp_cmdsn;
@@ -206,7 +214,7 @@ struct iscsi_nopout {
         uint8_t rsvd3;
         uint8_t dlength[3];
         uint8_t lun[8];
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be32  ttt;    /* Target Transfer Tag */
         __be32  cmdsn;
         __be32  exp_statsn;
@@ -221,7 +229,7 @@ struct iscsi_nopin {
         uint8_t rsvd3;
         uint8_t dlength[3];
         uint8_t lun[8];
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be32  ttt;    /* Target Transfer Tag */
         __be32  statsn;
         __be32  exp_cmdsn;
@@ -237,8 +245,8 @@ struct iscsi_tm {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t lun[8];
-        __be32  itt;    /* Initiator Task Tag */
-        __be32  rtt;    /* Reference Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
+        itt_t    rtt;   /* Reference Task Tag */
         __be32  cmdsn;
         __be32  exp_statsn;
         __be32  refcmdsn;
@@ -267,8 +275,8 @@ struct iscsi_tm_rsp {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t rsvd2[8];
-        __be32  itt;    /* Initiator Task Tag */
-        __be32  rtt;    /* Reference Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
+        itt_t    rtt;   /* Reference Task Tag */
         __be32  statsn;
         __be32  exp_cmdsn;
         __be32  max_cmdsn;
@@ -293,7 +301,7 @@ struct iscsi_r2t_rsp {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t lun[8];
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be32  ttt;    /* Target Transfer Tag */
         __be32  statsn;
         __be32  exp_cmdsn;
@@ -311,7 +319,7 @@ struct iscsi_data {
         uint8_t rsvd3;
         uint8_t dlength[3];
         uint8_t lun[8];
-        __be32  itt;
+        itt_t    itt;
         __be32  ttt;
         __be32  rsvd4;
         __be32  exp_statsn;
@@ -331,7 +339,7 @@ struct iscsi_data_rsp {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t lun[8];
-        __be32  itt;
+        itt_t    itt;
         __be32  ttt;
         __be32  statsn;
         __be32  exp_cmdsn;
@@ -355,7 +363,7 @@ struct iscsi_text {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t rsvd4[8];
-        __be32  itt;
+        itt_t    itt;
         __be32  ttt;
         __be32  cmdsn;
         __be32  exp_statsn;
@@ -373,7 +381,7 @@ struct iscsi_text_rsp {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t rsvd4[8];
-        __be32  itt;
+        itt_t    itt;
         __be32  ttt;
         __be32  statsn;
         __be32  exp_cmdsn;
@@ -392,7 +400,7 @@ struct iscsi_login {
         uint8_t dlength[3];
         uint8_t isid[6];        /* Initiator Session ID */
         __be16  tsih;   /* Target Session Handle */
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be16  cid;
         __be16  rsvd3;
         __be32  cmdsn;
@@ -421,7 +429,7 @@ struct iscsi_login_rsp {
         uint8_t dlength[3];
         uint8_t isid[6];        /* Initiator Session ID */
         __be16  tsih;   /* Target Session Handle */
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be32  rsvd3;
         __be32  statsn;
         __be32  exp_cmdsn;
@@ -478,7 +486,7 @@ struct iscsi_logout {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t rsvd2[8];
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be16  cid;
         uint8_t rsvd3[2];
         __be32  cmdsn;
@@ -505,7 +513,7 @@ struct iscsi_logout_rsp {
         uint8_t hlength;
         uint8_t dlength[3];
         uint8_t rsvd3[8];
-        __be32  itt;    /* Initiator Task Tag */
+        itt_t    itt;   /* Initiator Task Tag */
         __be32  rsvd4;
         __be32  statsn;
         __be32  exp_cmdsn;
@@ -528,7 +536,7 @@ struct iscsi_snack {
         uint8_t opcode;
         uint8_t flags;
         uint8_t rsvd2[14];
-        __be32  itt;
+        itt_t    itt;
         __be32  begrun;
         __be32  runlength;
         __be32  exp_statsn;