• Stefan Richter's avatar
    firewire: octlet AT payloads can be stack-allocated · f30e6d3e
    Stefan Richter authored
    We do not need slab allocations anymore in order to satisfy
    streaming DMA mapping constraints, thanks to commit da28947e
    "firewire: ohci: avoid separate DMA mapping for small AT payloads".
    (Besides, the slab-allocated buffers that firewire-core, firewire-sbp2,
    and firedtv used to provide for 8-byte write and lock requests were
    still not fully portable since they crossed cacheline boundaries or
    shared a cacheline with unrelated CPU-accessed data.  snd-firewire-lib
    got this aspect right by using an extra kmalloc/ kfree just for the
    8-byte transaction buffer.)
    This change replaces kmalloc'ed lock transaction scratch buffers in
    firewire-core, firedtv, and snd-firewire-lib by local stack allocations.
    Perhaps the most notable result of the change is simpler locking because
    there is no need to serialize usages of preallocated per-device buffers
    anymore.  Also, allocations and deallocations are simpler.
    Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
    Acked-by: default avatarClemens Ladisch <clemens@ladisch.de>
iso-resources.h 1.17 KB