• Ralf Baechle's avatar
    MIPS: Fix accessing to per-cpu data when flushing the cache · 2ce27762
    Ralf Baechle authored
    commit ff522058 upstream.
    
    This fixes the following issue
    
    BUG: using smp_processor_id() in preemptible [00000000] code: kjournald/1761
    caller is blast_dcache32+0x30/0x254
    Call Trace:
    [<8047f02c>] dump_stack+0x8/0x34
    [<802e7e40>] debug_smp_processor_id+0xe0/0xf0
    [<80114d94>] blast_dcache32+0x30/0x254
    [<80118484>] r4k_dma_cache_wback_inv+0x200/0x288
    [<80110ff0>] mips_dma_map_sg+0x108/0x180
    [<80355098>] ide_dma_prepare+0xf0/0x1b8
    [<8034eaa4>] do_rw_taskfile+0x1e8/0x33c
    [<8035951c>] ide_do_rw_disk+0x298/0x3e4
    [<8034a3c4>] do_ide_request+0x2e0/0x704
    [<802bb0dc>] __blk_run_queue+0x44/0x64
    [<802be000>] queue_unplugged.isra.36+0x1c/0x54
    [<802beb94>] blk_flush_plug_list+0x18c/0x24c
    [<802bec6c>] blk_finish_plug+0x18/0x48
    [<8026554c>] journal_commit_transaction+0x3b8/0x151c
    [<80269648>] kjournald+0xec/0x238
    [<8014ac00>] kthread+0xb8/0xc0
    [<8010268c>] ret_from_kernel_thread+0x14/0x1c
    
    Caches in most systems are identical - but not always, so we can't avoid
    the use of smp_call_function() by just looking at the boot CPU's data,
    have to fiddle with preemption instead.
    Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
    Cc: Markos Chandras <markos.chandras@imgtec.com>
    Cc: linux-mips@linux-mips.org
    Patchwork: https://patchwork.linux-mips.org/patch/5835Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
    2ce27762
c-r4k.c 37.4 KB