• John David Anglin's avatar
    parisc: Add nop instructions after TLB inserts · ad4aa06e
    John David Anglin authored
    An excerpt from the PA8800 ERS states:
    
    * The PA8800 violates the seven instruction pipeline rule when performing
      TLB inserts or PxTLBE instructions with the PSW C bit on. The instruction
      will take effect by the 12th instruction after the insert or purge.
    
    I believe we have a problem with handling TLB misses. We don't fill
    the pipeline following TLB inserts. As a result, we likely fault again
    after returning from the interruption.
    
    The above statement indicates that we need at least seven instructions
    after the insert on pre PA8800 processors and we need 12 instructions
    on PA8800/PA8900 processors.
    
    Here we add macros and code to provide the required number instructions
    after a TLB insert.
    Signed-off-by: default avatarJohn David Anglin <dave.anglin@bell.net>
    Suggested-by: default avatarHelge Deller <deller@gmx.de>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarHelge Deller <deller@gmx.de>
    ad4aa06e
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