• Pavel Kiryukhin's avatar
    [MIPS] Fix use of smp_processor_id() in preemptible code. · 54fd6441
    Pavel Kiryukhin authored
    Freeing prom memory: 956kb freed
    Freeing firmware memory: 978944k freed
    Freeing unused kernel memory: 180k freed
    BUG: using smp_processor_id() in preemptible [00000000] code: swapper/1
    caller is r4k_dma_cache_wback_inv+0x144/0x2a0
    Call Trace:
     [<80117af8>] r4k_dma_cache_wback_inv+0x144/0x2a0
     [<802e4b84>] debug_smp_processor_id+0xd4/0xf0
     [<802e4b7c>] debug_smp_processor_id+0xcc/0xf0
    ...
    CONFIG_DEBUG_PREEMPT is enabled.
    --
    Bug cause is blast_dcache_range() in preemptible code [in
    r4k_dma_cache_wback_inv()].
    blast_dcache_range() is constructed via __BUILD_BLAST_CACHE_RANGE that
    uses cpu_dcache_line_size(). It uses current_cpu_data that use
    smp_processor_id() in turn. In case of CONFIG_DEBUG_PREEMPT
    smp_processor_id emits BUG if we are executing with preemption
    enabled.
    
    Cpu options of cpu0 are assumed to be the superset of all processors.
    
    Can I make the same assumptions for cache line size  and fix this
    issue the following way:
    Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
    54fd6441
cpu-features.h 6.53 KB