• Jacob Keller's avatar
    ice: remove circular header dependencies on ice.h · 649c87c6
    Jacob Keller authored
    Several headers in the ice driver include ice.h even though they are
    themselves included by that header. The most notable of these is
    ice_common.h, but several other headers also do this.
    
    Such a recursive inclusion is problematic as it forces headers to be
    included in a strict order, otherwise compilation errors can result. The
    circular inclusions do not trigger an endless loop due to standard
    header inclusion guards, however other errors can occur.
    
    For example, ice_flow.h defines ice_rss_hash_cfg, which is used by
    ice_sriov.h as part of the definition of ice_vf_hash_ip_ctx.
    
    ice_flow.h includes ice_acl.h, which includes ice_common.h, and which
    finally includes ice.h. Since ice.h itself includes ice_sriov.h, this
    creates a circular dependency.
    
    The definition in ice_sriov.h requires things from ice_flow.h, but
    ice_flow.h itself will lead to trying to load ice_sriov.h as part of its
    process for expanding ice.h. The current code avoids this issue by
    having an implicit dependency without the include of ice_flow.h.
    
    If we were to fix that so that ice_sriov.h explicitly depends on
    ice_flow.h the following pattern would occur:
    
      ice_flow.h -> ice_acl.h -> ice_common.h -> ice.h -> ice_sriov.h
    
    At this point, during the expansion of, the header guard for ice_flow.h
    is already set, so when ice_sriov.h attempts to load the ice_flow.h
    header it is skipped. Then, we go on to begin including the rest of
    ice_sriov.h, including structure definitions which depend on
    ice_rss_hash_cfg. This produces a compiler warning because
    ice_rss_hash_cfg hasn't yet been included. Remember, we're just at the
    start of ice_flow.h!
    
    If the order of headers is incorrect (ice_flow.h is not implicitly
    loaded first in all files which include ice_sriov.h) then we get the
    same failure.
    
    Removing this recursive inclusion requires fixing a few cases where some
    headers depended on the header inclusions from ice.h. In addition, a few
    other changes are also required.
    
    Most notably, ice_hw_to_dev is implemented as a macro in ice_osdep.h,
    which is the likely reason that ice_common.h includes ice.h at all. This
    macro implementation requires the full definition of ice_pf in order to
    properly compile.
    
    Fix this by moving it to a function declared in ice_main.c, so that we
    do not require all files to depend on the layout of the ice_pf
    structure.
    
    Note that this change only fixes circular dependencies, but it does not
    fully resolve all implicit dependencies where one header may depend on
    the inclusion of another. I tried to fix as many of the implicit
    dependencies as I noticed, but fixing them all requires a somewhat
    tedious analysis of each header and attempting to compile it separately.
    Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
    Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
    Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
    649c87c6
ice_common.h 7.85 KB