target/linux/cns3xxx/patches-4.14/010-arm_introduce-dma-fiq-irq-broadcast.patch

   1 --- a/arch/arm/include/asm/glue-cache.h
   2 +++ b/arch/arm/include/asm/glue-cache.h
   3 @@ -152,9 +152,15 @@ static inline void nop_dma_unmap_area(co
   4  #define __cpuc_flush_user_range                __glue(_CACHE,_flush_user_cache_range)
   5  #define __cpuc_coherent_kern_range     __glue(_CACHE,_coherent_kern_range)
   6  #define __cpuc_coherent_user_range     __glue(_CACHE,_coherent_user_range)
   7 -#define __cpuc_flush_dcache_area       __glue(_CACHE,_flush_kern_dcache_area)
   8
   9 -#define dmac_flush_range               __glue(_CACHE,_dma_flush_range)
  10 +#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
  11 +# define __cpuc_flush_dcache_area      __glue(_CACHE,_flush_kern_dcache_area)
  12 +# define dmac_flush_range              __glue(_CACHE,_dma_flush_range)
  13 +#else
  14 +# define __cpuc_flush_dcache_area      __glue(fiq,_flush_kern_dcache_area)
  15 +# define dmac_flush_range              __glue(fiq,_dma_flush_range)
  16 +#endif
  17 +
  18  #endif
  19
  20  #endif
  21 --- a/arch/arm/mm/Kconfig
  22 +++ b/arch/arm/mm/Kconfig
  23 @@ -922,6 +922,17 @@ config DMA_CACHE_RWFO
  24           in hardware, other workarounds are needed (e.g. cache
  25           maintenance broadcasting in software via FIQ).
  26
  27 +config DMA_CACHE_FIQ_BROADCAST
  28 +       bool "Enable fiq broadcast DMA cache maintenance"
  29 +       depends on CPU_V6K && SMP
  30 +       select FIQ
  31 +       help
  32 +         The Snoop Control Unit on ARM11MPCore does not detect the
  33 +         cache maintenance operations and the dma_{map,unmap}_area()
  34 +         functions may leave stale cache entries on other CPUs. By
  35 +         enabling this option, fiq broadcast in the ARMv6
  36 +         DMA cache maintenance functions is performed.
  37 +
  38  config OUTER_CACHE
  39         bool
  40
  41 --- a/arch/arm/mm/flush.c
  42 +++ b/arch/arm/mm/flush.c
  43 @@ -319,6 +319,7 @@ void __sync_icache_dcache(pte_t pteval)
  44  void flush_dcache_page(struct page *page)
  45  {
  46         struct address_space *mapping;
  47 +       bool skip_broadcast = true;
  48
  49         /*
  50          * The zero page is never written to, so never has any dirty
  51 @@ -335,7 +336,10 @@ void flush_dcache_page(struct page *page
  52
  53         mapping = page_mapping(page);
  54
  55 -       if (!cache_ops_need_broadcast() &&
  56 +#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
  57 +        skip_broadcast = !cache_ops_need_broadcast();
  58 +#endif
  59 +        if (skip_broadcast &&
  60             mapping && !page_mapcount(page))
  61                 clear_bit(PG_dcache_clean, &page->flags);
  62         else {
  63 --- a/arch/arm/mm/dma.h
  64 +++ b/arch/arm/mm/dma.h
  65 @@ -5,8 +5,13 @@
  66  #include <asm/glue-cache.h>
  67
  68  #ifndef MULTI_CACHE
  69 -#define dmac_map_area                  __glue(_CACHE,_dma_map_area)
  70 -#define dmac_unmap_area                __glue(_CACHE,_dma_unmap_area)
  71 +#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
  72 +# define dmac_map_area                 __glue(_CACHE,_dma_map_area)
  73 +# define dmac_unmap_area               __glue(_CACHE,_dma_unmap_area)
  74 +#else
  75 +# define dmac_map_area                 __glue(fiq,_dma_map_area)
  76 +# define dmac_unmap_area                       __glue(fiq,_dma_unmap_area)
  77 +#endif
  78
  79  /*
  80   * These are private to the dma-mapping API.  Do not use directly.