• Alex Elder's avatar
    net: ipa: properly limit modem routing table use · cf412ec3
    Alex Elder authored
    IPA can route packets between IPA-connected entities.  The AP and
    modem are currently the only such entities supported, and no routing
    is required to transfer packets between them.
    
    The number of entries in each routing table is fixed, and defined at
    initialization time.  Some of these entries are designated for use
    by the modem, and the rest are available for the AP to use.  The AP
    sends a QMI message to the modem which describes (among other
    things) information about routing table memory available for the
    modem to use.
    
    Currently the QMI initialization packet gives wrong information in
    its description of routing tables.  What *should* be supplied is the
    maximum index that the modem can use for the routing table memory
    located at a given location.  The current code instead supplies the
    total *number* of routing table entries.  Furthermore, the modem is
    granted the entire table, not just the subset it's supposed to use.
    
    This patch fixes this.  First, the ipa_mem_bounds structure is
    generalized so its "end" field can be interpreted either as a final
    byte offset, or a final array index.  Second, the IPv4 and IPv6
    (non-hashed and hashed) table information fields in the QMI
    ipa_init_modem_driver_req structure are changed to be ipa_mem_bounds
    rather than ipa_mem_array structures.  Third, we set the "end" value
    for each routing table to be the last index, rather than setting the
    "count" to be the number of indices.  Finally, instead of allowing
    the modem to use all of a routing table's memory, it is limited to
    just the portion meant to be used by the modem.  In all versions of
    IPA currently supported, that is IPA_ROUTE_MODEM_COUNT (8) entries.
    
    Update a few comments for clarity.
    
    Fixes: 530f9216 ("soc: qcom: ipa: AP/modem communications")
    Signed-off-by: default avatarAlex Elder <elder@linaro.org>
    Link: https://lore.kernel.org/r/20220913204602.1803004-1-elder@linaro.orgSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
    cf412ec3
ipa_qmi_msg.h 8.96 KB