OA49723: WITH RETURN CODE 8, THE IQPINFO MACRO NO LONGER RETURNS A REQUIRED LENGTH AFTER APPLYING PTF UA90971 16/03/09 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• PTF UA90971 for APAR OA44791 introduced changes in the code of
  module IQPPRINF (IQPINFO macro processor). One of the changes
  resulted in returning RC08 without updating a value in the
  PERFDATALEN field. This update for RC8 is expected, according to
  the documented return codes for the IQPINFO macro, but no longer
  happens after applying the PTF.
  
   EXTERNAL SYMPTOMS:
  
    A caller of the IQPINFO macro receives return code 8 but the
   PERFDATALEN field is not updated with the required minimum size
   of a data area as expected.
   PTF UA90971 has been installed.
   ANALYSIS:
  
   The code at the PTF level checks a buffer length inside the
   ScanPCT program loop but before the loop is able to turn the
   F_AllocFcnFound bit on. This bit remains turned off when
   ScanPCT is exited after discovering an insufficient buffer
   length. Since the bit is off, the module bypasses final
   processing that should have saved a calculated buffer length in
   the macro parameters. So, RC08 is returned to the caller
   without the expected update in the PERFDATALEN parameter
   KNOWN IMPACT:
  
   A user of the IQPINFO macro can not rely on the contents of the
   PERFDATALEN parameter after getting return code 08 ( RC08 )
   VERIFICATION STEPS:
  
   PTF UA90971 for APAR OA44791 is installed on the system
  

Local fix

• BYPASS/CIRCUMVENTION:
  
   It is possible to bypass this problem with the IQPINFO service,
   by setting the PerfDataLen to a value that doubles the Perf_Len
   value.  This was generated within the IQPYPERF macro.  This
   will help avoid the RC8.
  PE Information:
   User's Affected:
     PTF UA90971 for APAR OA44791 with HBB7790, using the IQPINFO
    Service for zEDC (Compression) and RoCE (Communications)
   devices.
  User Impact:
    APAR OA44791 fixed the problem it reported but introduced
   a new problem.
     Users of the IQPINFO Service will still receive a RC8
    when the callers buffer length is too small, but the
    returned required length (PerfDataLen field) will not be
    filled in correctly.  This will result in further attempts
    to also fail processing, due to the RC8 (Buffer length too
    small).
   Clearly better off with the original APAR on the system:
      The original APAR's enhancements and fixes are needed with
    the z13 processor, but this did introduce a problem where
    the required buffer length was not properly updated
    within the IQPINFO service. This was a small problem in
    comparison with the functions provided by the original
    APAR.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users at HBB7790 and above using IQPINFO     *
  *                 service for zEDC or RoCE devices,            *
  *                 with PTF UA90971 (OA44791) installed.        *
  ****************************************************************
  * PROBLEM DESCRIPTION: Users of the IQPINFO Service will       *
  *                      still receive a RC8 when the caller's   *
  *                      buffer length is too small, but the     *
  *                      returned required length (PerfDataLen   *
  *                      field) will not be filled in            *
  *                      correctly. This will result in          *
  *                      further attempts to also fail           *
  *                      processing, due to the RC8 (Buffer      *
  *                      length too small).                      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When the IQPINFO service issued a return code of 8, the
  required buffer length returned was 0. Previously, the
  service provided the correct buffer length required
  to successfully process the request.
  

Problem conclusion

• The IQPINFO service will provide the required buffer size
  when the user provided buffer size is too small.
  
  *************************************************************
  * FUNCTION AFFECTED: BCP                          (OA49723) *
  *                      PCIE Services                        *
  *************************************************************
  * DESCRIPTION      : Documentation updates                  *
  *************************************************************
  * TIMING           : As Needed                              *
  *************************************************************
  Title: MVS Programming: Authorized Assembler Services
                          Reference (EDT-IXG) {SA23-1373-xx}
  
   IQPINFO  Obtain PCIe information
  
    Description
     The IQPINFO macro provides PCIe-related information,
      including any performance statistics.
    Environment
  
    The requirements for the caller are:
      Environmental factor     Requirement
      Minimum authorization:   Supervisor state and PSW key 0
      Dispatchable unit mode:  Task or SRB mode
      Dispatchable unit mode:  Task or SRB mode
      Cross memory mode:       Any PASN, any HASN, any SASN
      AMODE:                   31- or 64-bit
      ASC mode:                Primary
      Interrupt status:        Enabled for I/O and external
                               interrupts
      Locks:                   The caller may hold locks, but
                               is not required to hold any.
      Control parameters:      Must be in the primary address
                               space.
      Programming requirements
        None.
      Restrictions
  
    |   Note: With the z13 enhancement of IQPINFO service,
    |         it is possible that the required buffer length
    |         can change depending on the device, eg. RoCe or
    |         zEDC, since different devices return their
    |         specialized data. With this update, users of the
    |         IQPINFO service will have to be prepared that
    |         the required length returned might not be valid
    |         for all devices.
       ....
   KEYWORDS: ZEDC/K
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UA81082 UA81083

Modules/Macros

• FPGPPERF IQPPRINF
  

Fix information

• Fixed component name

  PCIE SERVICES

• Fixed component ID

  5752SCIQP

Applicable component levels

• R7A0 PSY UA81082

     UP16/03/30 P F603 «

• R790 PSY UA81083

     UP16/03/30 P F603 «

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.