ieee1394: sbp2: more checks of status block

 - Add checks for the (very unlikely) cases that the target writes too
   little or too much status data or writes unsolicited status.
 - Indicate that these and similar conditions are unlikely().
 - Check the 'resp' and 'sbp_status' fields for possible failure status.
 - Slightly optimize access macros for the status block bitfields.
 - Unify a few related log messages.

TODO:  Check if 'src'==1, then withhold the respective ORB from reuse
until status for any subsequent ORB was received.  This is an old bug
whose fix requires more complex command queue handling.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

2 files changed, 38 insertions, 46 deletions

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index c6776909747..07030be0ef2 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -1201,11 +1201,8 @@ static int sbp2_query_logins(struct scsi_id_instance_data *scsi_id)
                 return -EIO;
         }
 
-        if (STATUS_GET_RESP(scsi_id->status_block.ORB_offset_hi_misc) ||
-            STATUS_GET_DEAD_BIT(scsi_id->status_block.ORB_offset_hi_misc) ||
-            STATUS_GET_SBP_STATUS(scsi_id->status_block.ORB_offset_hi_misc)) {
-
-                SBP2_INFO("Error querying logins to SBP-2 device - timed out");
+        if (STATUS_TEST_RDS(scsi_id->status_block.ORB_offset_hi_misc)) {
+                SBP2_INFO("Error querying logins to SBP-2 device - failed");
                 return -EIO;
         }
 
@@ -1298,18 +1295,12 @@ static int sbp2_login_device(struct scsi_id_instance_data *scsi_id)
          * Sanity. Make sure status returned matches login orb.
          */
         if (scsi_id->status_block.ORB_offset_lo != scsi_id->login_orb_dma) {
-                SBP2_ERR("Error logging into SBP-2 device - login timed-out");
+                SBP2_ERR("Error logging into SBP-2 device - timed out");
                 return -EIO;
         }
 
-        /*
-         * Check status
-         */
-        if (STATUS_GET_RESP(scsi_id->status_block.ORB_offset_hi_misc) ||
-            STATUS_GET_DEAD_BIT(scsi_id->status_block.ORB_offset_hi_misc) ||
-            STATUS_GET_SBP_STATUS(scsi_id->status_block.ORB_offset_hi_misc)) {
-
-                SBP2_ERR("Error logging into SBP-2 device - login failed");
+        if (STATUS_TEST_RDS(scsi_id->status_block.ORB_offset_hi_misc)) {
+                SBP2_ERR("Error logging into SBP-2 device - failed");
                 return -EIO;
         }
 
@@ -1333,9 +1324,7 @@ static int sbp2_login_device(struct scsi_id_instance_data *scsi_id)
         scsi_id->sbp2_command_block_agent_addr &= 0x0000ffffffffffffULL;
 
         SBP2_INFO("Logged into SBP-2 device");
-
         return 0;
-
 }
 
 /*
@@ -1466,25 +1455,17 @@ static int sbp2_reconnect_device(struct scsi_id_instance_data *scsi_id)
          * Sanity. Make sure status returned matches reconnect orb.
          */
         if (scsi_id->status_block.ORB_offset_lo != scsi_id->reconnect_orb_dma) {
-                SBP2_ERR("Error reconnecting to SBP-2 device - reconnect timed-out");
+                SBP2_ERR("Error reconnecting to SBP-2 device - timed out");
                 return -EIO;
         }
 
-        /*
-         * Check status
-         */
-        if (STATUS_GET_RESP(scsi_id->status_block.ORB_offset_hi_misc) ||
-            STATUS_GET_DEAD_BIT(scsi_id->status_block.ORB_offset_hi_misc) ||
-            STATUS_GET_SBP_STATUS(scsi_id->status_block.ORB_offset_hi_misc)) {
-
-                SBP2_ERR("Error reconnecting to SBP-2 device - reconnect failed");
+        if (STATUS_TEST_RDS(scsi_id->status_block.ORB_offset_hi_misc)) {
+                SBP2_ERR("Error reconnecting to SBP-2 device - failed");
                 return -EIO;
         }
 
         HPSB_DEBUG("Reconnected to SBP-2 device");
-
         return 0;
-
 }
 
 /*
@@ -2115,18 +2096,19 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
 
         sbp2util_packet_dump(data, length, "sbp2 status write by device", (u32)addr);
 
-        if (!host) {
+        if (unlikely(length < 8 || length > sizeof(struct sbp2_status_block))) {
+                SBP2_ERR("Wrong size of status block");
+                return RCODE_ADDRESS_ERROR;
+        }
+        if (unlikely(!host)) {
                 SBP2_ERR("host is NULL - this is bad!");
                 return RCODE_ADDRESS_ERROR;
         }
-
         hi = hpsb_get_hostinfo(&sbp2_highlevel, host);
-
-        if (!hi) {
+        if (unlikely(!hi)) {
                 SBP2_ERR("host info is NULL - this is bad!");
                 return RCODE_ADDRESS_ERROR;
         }
-
         /*
          * Find our scsi_id structure by looking at the status fifo address
          * written to by the sbp2 device.
@@ -2138,8 +2120,7 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
                         break;
                 }
         }
-
-        if (!scsi_id) {
+        if (unlikely(!scsi_id)) {
                 SBP2_ERR("scsi_id is NULL - device is gone?");
                 return RCODE_ADDRESS_ERROR;
         }
@@ -2156,12 +2137,14 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
         sbp2util_be32_to_cpu_buffer(sb, 8);
 
         /*
-         * Handle command ORB status here if necessary. First, need to match
-         * status with command.
+         * Ignore unsolicited status. Handle command ORB status.
          */
-        command = sbp2util_find_command_for_orb(scsi_id, sb->ORB_offset_lo);
+        if (unlikely(STATUS_GET_SRC(sb->ORB_offset_hi_misc) == 2))
+                command = NULL;
+        else
+                command = sbp2util_find_command_for_orb(scsi_id,
+                                                        sb->ORB_offset_lo);
         if (command) {
-
                 SBP2_DEBUG("Found status for command ORB");
                 pci_dma_sync_single_for_cpu(hi->host->pdev, command->command_orb_dma,
                                             sizeof(struct sbp2_command_orb),
@@ -2177,16 +2160,23 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
                  * Matched status with command, now grab scsi command pointers
                  * and check status.
                  */
+                /*
+                 * FIXME: If the src field in the status is 1, the ORB DMA must
+                 * not be reused until status for a subsequent ORB is received.
+                 */
                 SCpnt = command->Current_SCpnt;
                 spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
                 sbp2util_mark_command_completed(scsi_id, command);
                 spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
 
                 if (SCpnt) {
+                        if (STATUS_TEST_RS(sb->ORB_offset_hi_misc))
+                                scsi_status =
+                                        SBP2_SCSI_STATUS_COMMAND_TERMINATED;
                         /*
                          * See if the target stored any scsi status information.
                          */
-                        if (STATUS_GET_LENGTH(sb->ORB_offset_hi_misc) > 1) {
+                        if (STATUS_GET_LEN(sb->ORB_offset_hi_misc) > 1) {
                                 SBP2_DEBUG("CHECK CONDITION");
                                 scsi_status = sbp2_status_to_sense_data(
                                         (unchar *)sb, SCpnt->sense_buffer);
@@ -2196,7 +2186,7 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
                          * Check to see if the dead bit is set. If so, we'll
                          * have to initiate a fetch agent reset.
                          */
-                        if (STATUS_GET_DEAD_BIT(sb->ORB_offset_hi_misc)) {
+                        if (STATUS_TEST_D(sb->ORB_offset_hi_misc)) {
                                 SBP2_DEBUG("Dead bit set - "
                                            "initiating fetch agent reset");
                                 sbp2_agent_reset(scsi_id, 0);
diff --git a/drivers/ieee1394/sbp2.h b/drivers/ieee1394/sbp2.h
index b17016b7cfc..34e3d37fc79 100644
--- a/drivers/ieee1394/sbp2.h
+++ b/drivers/ieee1394/sbp2.h
@@ -180,12 +180,14 @@ struct sbp2_unrestricted_page_table {
 
 #define SBP2_SCSI_STATUS_SELECTION_TIMEOUT      0xff
 
-#define STATUS_GET_ORB_OFFSET_HI(value)         (value & 0xffff)
-#define STATUS_GET_SBP_STATUS(value)            ((value >> 16) & 0xff)
-#define STATUS_GET_LENGTH(value)                ((value >> 24) & 0x7)
-#define STATUS_GET_DEAD_BIT(value)              ((value >> 27) & 0x1)
-#define STATUS_GET_RESP(value)                  ((value >> 28) & 0x3)
-#define STATUS_GET_SRC(value)                   ((value >> 30) & 0x3)
+#define STATUS_GET_SRC(value)                   (((value) >> 30) & 0x3)
+#define STATUS_GET_LEN(value)                   (((value) >> 24) & 0x7)
+#define STATUS_GET_ORB_OFFSET_HI(value)         ((value) & 0x0000ffff)
+#define STATUS_TEST_D(value)                    ((value) & 0x08000000)
+/* test 'resp' | 'sbp2_status' */
+#define STATUS_TEST_RS(value)                   ((value) & 0x30ff0000)
+/* test 'resp' | 'dead' | 'sbp2_status' */
+#define STATUS_TEST_RDS(value)                  ((value) & 0x38ff0000)
 
 struct sbp2_status_block {
         u32 ORB_offset_hi_misc;