target/linux/brcm63xx/patches-3.14/020-MIPS-BCM63XX-replace-irq-dispatch-code-with-a-generi.patch

   1 From 39b46ed1c9fe71890566e129d9ac5feb8421b3b4 Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jogo@openwrt.org>
   3 Date: Thu, 18 Apr 2013 21:14:49 +0200
   4 Subject: [PATCH 03/10] MIPS: BCM63XX: replace irq dispatch code with a generic
   5  version
   6
   7 The generic version uses a variable length of u32 registers instead of u32/u64.
   8 This allows easier support for "wider" registers without having to rewrite
   9 everything.
  10
  11 This "generic" version is as fast as the old version in the best case
  12 (i == next set bit), and twice as fast in the worst case in 64 bits.
  13
  14 Using a macro was chosen over a (forced) inline version because gcc generated
  15 more compact code with the macro.
  16
  17 The change from (signed) int to unsigned int for i and to_call was intentional
  18 as the value can be only between 0 and (width - 1) anyway, and allowed gcc to
  19 optimise the code a bit further.
  20
  21 Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  22 ---
  23  arch/mips/bcm63xx/irq.c | 130 +++++++++++++++++++++---------------------------
  24  1 file changed, 56 insertions(+), 74 deletions(-)
  25
  26 --- a/arch/mips/bcm63xx/irq.c
  27 +++ b/arch/mips/bcm63xx/irq.c
  28 @@ -51,47 +51,65 @@ static inline void handle_internal(int i
  29   * will resume the loop where it ended the last time we left this
  30   * function.
  31   */
  32 -static void __dispatch_internal_32(void)
  33 -{
  34 -       u32 pending;
  35 -       static int i;
  36 -
  37 -       pending = bcm_readl(irq_stat_addr) & bcm_readl(irq_mask_addr);
  38 -
  39 -       if (!pending)
  40 -               return ;
  41 -
  42 -       while (1) {
  43 -               int to_call = i;
  44
  45 -               i = (i + 1) & 0x1f;
  46 -               if (pending & (1 << to_call)) {
  47 -                       handle_internal(to_call);
  48 -                       break;
  49 -               }
  50 -       }
  51 +#define BUILD_IPIC_INTERNAL(width)                                     \
  52 +void __dispatch_internal_##width(void)                                 \
  53 +{                                                                      \
  54 +       u32 pending[width / 32];                                        \
  55 +       unsigned int src, tgt;                                          \
  56 +       bool irqs_pending = false;                                      \
  57 +       static unsigned int i;                                          \
  58 +                                                                       \
  59 +       /* read registers in reverse order */                           \
  60 +       for (src = 0, tgt = (width / 32); src < (width / 32); src++) {  \
  61 +               u32 val;                                                \
  62 +                                                                       \
  63 +               val = bcm_readl(irq_stat_addr + src * sizeof(u32));     \
  64 +               val &= bcm_readl(irq_mask_addr + src * sizeof(u32));    \
  65 +               pending[--tgt] = val;                                   \
  66 +                                                                       \
  67 +               if (val)                                                \
  68 +                       irqs_pending = true;                            \
  69 +       }                                                               \
  70 +                                                                       \
  71 +       if (!irqs_pending)                                              \
  72 +               return;                                                 \
  73 +                                                                       \
  74 +       while (1) {                                                     \
  75 +               unsigned int to_call = i;                               \
  76 +                                                                       \
  77 +               i = (i + 1) & (width - 1);                              \
  78 +               if (pending[to_call / 32] & (1 << (to_call & 0x1f))) {  \
  79 +                       handle_internal(to_call);                       \
  80 +                       break;                                          \
  81 +               }                                                       \
  82 +       }                                                               \
  83 +}                                                                      \
  84 +                                                                       \
  85 +static void __internal_irq_mask_##width(unsigned int irq)              \
  86 +{                                                                      \
  87 +       u32 val;                                                        \
  88 +       unsigned reg = (irq / 32) ^ (width/32 - 1);                     \
  89 +       unsigned bit = irq & 0x1f;                                      \
  90 +                                                                       \
  91 +       val = bcm_readl(irq_mask_addr + reg * sizeof(u32));             \
  92 +       val &= ~(1 << bit);                                             \
  93 +       bcm_writel(val, irq_mask_addr + reg * sizeof(u32));             \
  94 +}                                                                      \
  95 +                                                                       \
  96 +static void __internal_irq_unmask_##width(unsigned int irq)            \
  97 +{                                                                      \
  98 +       u32 val;                                                        \
  99 +       unsigned reg = (irq / 32) ^ (width/32 - 1);                     \
 100 +       unsigned bit = irq & 0x1f;                                      \
 101 +                                                                       \
 102 +       val = bcm_readl(irq_mask_addr + reg * sizeof(u32));             \
 103 +       val |= (1 << bit);                                              \
 104 +       bcm_writel(val, irq_mask_addr + reg * sizeof(u32));             \
 105  }
 106
 107 -static void __dispatch_internal_64(void)
 108 -{
 109 -       u64 pending;
 110 -       static int i;
 111 -
 112 -       pending = bcm_readq(irq_stat_addr) & bcm_readq(irq_mask_addr);
 113 -
 114 -       if (!pending)
 115 -               return ;
 116 -
 117 -       while (1) {
 118 -               int to_call = i;
 119 -
 120 -               i = (i + 1) & 0x3f;
 121 -               if (pending & (1ull << to_call)) {
 122 -                       handle_internal(to_call);
 123 -                       break;
 124 -               }
 125 -       }
 126 -}
 127 +BUILD_IPIC_INTERNAL(32);
 128 +BUILD_IPIC_INTERNAL(64);
 129
 130  asmlinkage void plat_irq_dispatch(void)
 131  {
 132 @@ -128,42 +146,6 @@ asmlinkage void plat_irq_dispatch(void)
 133   * internal IRQs operations: only mask/unmask on PERF irq mask
 134   * register.
 135   */
 136 -static void __internal_irq_mask_32(unsigned int irq)
 137 -{
 138 -       u32 mask;
 139 -
 140 -       mask = bcm_readl(irq_mask_addr);
 141 -       mask &= ~(1 << irq);
 142 -       bcm_writel(mask, irq_mask_addr);
 143 -}
 144 -
 145 -static void __internal_irq_mask_64(unsigned int irq)
 146 -{
 147 -       u64 mask;
 148 -
 149 -       mask = bcm_readq(irq_mask_addr);
 150 -       mask &= ~(1ull << irq);
 151 -       bcm_writeq(mask, irq_mask_addr);
 152 -}
 153 -
 154 -static void __internal_irq_unmask_32(unsigned int irq)
 155 -{
 156 -       u32 mask;
 157 -
 158 -       mask = bcm_readl(irq_mask_addr);
 159 -       mask |= (1 << irq);
 160 -       bcm_writel(mask, irq_mask_addr);
 161 -}
 162 -
 163 -static void __internal_irq_unmask_64(unsigned int irq)
 164 -{
 165 -       u64 mask;
 166 -
 167 -       mask = bcm_readq(irq_mask_addr);
 168 -       mask |= (1ull << irq);
 169 -       bcm_writeq(mask, irq_mask_addr);
 170 -}
 171 -
 172  static void bcm63xx_internal_irq_mask(struct irq_data *d)
 173  {
 174         internal_irq_mask(d->irq - IRQ_INTERNAL_BASE);