Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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:Jacob Keller <jacob.e.keller@intel.com> Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel) Signed-off-by:
Tony Nguyen <anthony.l.nguyen@intel.com>