target/linux/generic/patches-3.10/131-improve_noncoherent_dma_checks.patch

   1 From d593f8fc627f8cdaee9c14e4d22b0770a09baaf1 Mon Sep 17 00:00:00 2001
   2 From: Felix Fietkau <nbd@openwrt.org>
   3 Date: Thu, 15 Aug 2013 10:47:47 +0200
   4 Subject: [PATCH] MIPS: improve checks for noncoherent DMA
   5
   6 Only one MIPS development board actually supports enabling/disabling DMA
   7 coherency at runtime, so it's not a good idea to push the overhead of
   8 checking that configuration setting onto every other supported target as
   9 well.
  10
  11 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
  12 ---
  13  arch/mips/Kconfig                                  | 6 +++++-
  14  arch/mips/include/asm/dma-coherence.h              | 7 +++++++
  15  arch/mips/include/asm/mach-generic/dma-coherence.h | 4 ----
  16  arch/mips/mm/dma-default.c                         | 2 ++
  17  4 files changed, 14 insertions(+), 5 deletions(-)
  18
  19 --- a/arch/mips/Kconfig
  20 +++ b/arch/mips/Kconfig
  21 @@ -296,7 +296,7 @@ config MIPS_MALTA
  22         select CEVT_R4K
  23         select CSRC_R4K
  24         select CSRC_GIC
  25 -       select DMA_NONCOHERENT
  26 +       select DMA_MAYBE_COHERENT
  27         select GENERIC_ISA_DMA
  28         select HAVE_PCSPKR_PLATFORM
  29         select IRQ_CPU
  30 @@ -947,6 +947,10 @@ config FW_CFE
  31  config ARCH_DMA_ADDR_T_64BIT
  32         def_bool (HIGHMEM && 64BIT_PHYS_ADDR) || 64BIT
  33
  34 +config DMA_MAYBE_COHERENT
  35 +       select DMA_NONCOHERENT
  36 +       bool
  37 +
  38  config DMA_COHERENT
  39         bool
  40
  41 --- a/arch/mips/include/asm/dma-coherence.h
  42 +++ b/arch/mips/include/asm/dma-coherence.h
  43 @@ -9,7 +9,14 @@
  44  #ifndef __ASM_DMA_COHERENCE_H
  45  #define __ASM_DMA_COHERENCE_H
  46
  47 +#ifdef CONFIG_DMA_MAYBE_COHERENT
  48  extern int coherentio;
  49  extern int hw_coherentio;
  50 +#elif defined(CONFIG_DMA_COHERENT)
  51 +#define coherentio     1
  52 +#else
  53 +#define coherentio     0
  54 +#endif
  55 +#define hw_coherentio  0
  56
  57  #endif
  58 --- a/arch/mips/include/asm/mach-generic/dma-coherence.h
  59 +++ b/arch/mips/include/asm/mach-generic/dma-coherence.h
  60 @@ -49,11 +49,7 @@ static inline int plat_dma_supported(str
  61
  62  static inline int plat_device_is_coherent(struct device *dev)
  63  {
  64 -#ifdef CONFIG_DMA_COHERENT
  65 -       return 1;
  66 -#else
  67         return coherentio;
  68 -#endif
  69  }
  70
  71  #endif /* __ASM_MACH_GENERIC_DMA_COHERENCE_H */
  72 --- a/arch/mips/mm/dma-default.c
  73 +++ b/arch/mips/mm/dma-default.c
  74 @@ -22,6 +22,7 @@
  75
  76  #include <dma-coherence.h>
  77
  78 +#ifdef CONFIG_DMA_MAYBE_COHERENT
  79  int coherentio = 0;    /* User defined DMA coherency from command line. */
  80  EXPORT_SYMBOL_GPL(coherentio);
  81  int hw_coherentio = 0; /* Actual hardware supported DMA coherency setting. */
  82 @@ -41,6 +42,7 @@ static int __init setnocoherentio(char *
  83         return 0;
  84  }
  85  early_param("nocoherentio", setnocoherentio);
  86 +#endif
  87
  88  static inline struct page *dma_addr_to_page(struct device *dev,
  89         dma_addr_t dma_addr)