dmaengine: pl330: fix double lock

The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:

    Double lock:
    1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236;
    2. call to function `pl330_release_channel' immediately after;
    3. call to function `dma_pl330_rqcb' in line 1753;
    4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505.

I have fixed it as suggested by Marek Szyprowski.

First, I have replaced `pch->lock' with `pl330->lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.

NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch->work_list' under lock `pl330->lock',
whereas in the rest of the code `pch->work_list' is protected by
`pch->lock'. I don't know if this may cause race conditions. Similarly
`pch->cyclic' is written by `pl330_alloc_chan_resources' under
`pl330->lock' but read by `pl330_tx_submit' under `pch->lock'.

Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.

Signed-off-by: Iago Abal <mail@iagoabal.eu>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

path: root/ifpps.zsh

#compdef ifpps
#
# ifpps.zsh -- zsh completion function for ifpps
#
# Copyright (C) 2013 Hideo Hattori <hhatto.jp@gmail.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.

typeset -A opt_args

_interfaces () {
    _wanted interfaces expl 'network interface' \
    _net_interfaces
    _values "Pseudo-device that captures on all interfaces" "any"
}

_arguments -s -S \
    "(-d --dev)"{-d,--dev}"[Device to fetch statistics for i.e., eth0]:device:_interfaces" \
    "(-p --promisc)"{-p,--promisc}"[Promiscuous mode]" \
    "(-P --percentage)"{-P,--percentage}"[Show percentage of theoretical line rate]" \
    "(-t --interval)"{-t,--interval}"[Refresh time in sec (default 1 s)]:interval:_gnu_generic" \
    "(-n --num-cpus)"{-n,--num-cpus}"[Number of top hitter CPUs to display in ncurses mode (default 10)]" \
    "(-C --csv)"{-C,--csv}"[Output to terminal as CSV  E.g. post-processing with Gnuplot et al.]" \
    "(-l --loop)"{-l,--loop}"[Loop terminal output]" \
    "(-m --median)"{-m,--median}"[Display median values]" \
    "(-W --no-warn)"{-W,--no-warn}"[Suppress warnings]" \
    {-v,--version}"[Print version]:" \
    {-h,--help}"[Print this help]:" \
    "*::args:_gnu_generic"