• Rahul Verma's avatar
    qed: Don't use main-ptt in unrelated flows · 15582962
    Rahul Verma authored
    In order to access HW registers driver needs to acquire a PTT entry
    [mapping between bar memory and internal chip address].
    Since acquiring PTT entries could fail [at least in theory] as their
    number is finite and other flows can hold them, we reserve special PTT
    entries for 'important' enough flows - ones we want to guarantee that
    would not be susceptible to such issues.
    
    One such special entry is the 'main' PTT which is meant to be used in
    flows such as chip initialization and de-initialization.
    However, there are other flows that are also using that same entry
    for their own purpose, and might run concurrently with the original
    flows [notice that for most cases using the main-ptt by mistake, such
    a race is still impossible, at least today].
    
    This patch re-organizes the various functions that currently use the
    main_ptt in one of two ways:
    
      - If a function shouldn't use the main_ptt it starts acquiring and
        releasing it's own PTT entry and use it instead. Notice if those
        functions previously couldn't fail, they now can [as acquisition
        might fail].
    
      - Change the prototypes so that the main_ptt would be received as
        a parameter [instead of explicitly accessing it].
        This prevents the future risk of adding codes that introduces new
        use-cases for flows using the main_ptt, ones that might be in race
        with the actual 'main' flows.
    Signed-off-by: default avatarRahul Verma <Rahul.Verma@cavium.com>
    Signed-off-by: default avatarYuval Mintz <Yuval.Mintz@cavium.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    15582962
qed_spq.c 25.3 KB