MIPS: BCM63xx: Replace irq dispatch code with a generic version

The generic version uses a variable length of u32 registers instead of u32/u64.
This allows easier support for "wider" registers without having to rewrite
everything.

This "generic" version is as fast as the old version in the best case
(i == next set bit), and twice as fast in the worst case in 64 bits.

Using a macro was chosen over a (forced) inline version because gcc generated
more compact code with the macro.

The change from (signed) int to unsigned int for i and to_call was intentional
as the value can be only between 0 and (width - 1) anyway, and allowed gcc to
optimise the code a bit further.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: John Crispin <blogic@openwrt.org>
Cc: Maxime Bizon <mbizon@freebox.fr>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Gregory Fong <gregory.0xf0@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/7316/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/bcm63xx/irq.c b/arch/mips/bcm63xx/irq.c
index f6c933a68c75828a658569af945f04f2e2c370ec..db9f2ef76ebe3eaace9cbdd5d474595cfdd112a3 100644 (file)
--- a/arch/mips/bcm63xx/irq.c
+++ b/arch/mips/bcm63xx/irq.c
@@ -51,47 +51,65 @@ static inline void handle_internal(int intbit)
  * will resume the loop where it ended the last time we left this
  * function.
  */
-static void __dispatch_internal_32(void)
-{
-       u32 pending;
-       static int i;
-
-       pending = bcm_readl(irq_stat_addr) & bcm_readl(irq_mask_addr);
-
-       if (!pending)
-               return ;
-
-       while (1) {
-               int to_call = i;
 
-               i = (i + 1) & 0x1f;
-               if (pending & (1 << to_call)) {
-                       handle_internal(to_call);
-                       break;
-               }
-       }
+#define BUILD_IPIC_INTERNAL(width)                                     \
+void __dispatch_internal_##width(void)                                 \
+{                                                                      \
+       u32 pending[width / 32];                                        \
+       unsigned int src, tgt;                                          \
+       bool irqs_pending = false;                                      \
+       static unsigned int i;                                          \
+                                                                       \
+       /* read registers in reverse order */                           \
+       for (src = 0, tgt = (width / 32); src < (width / 32); src++) {  \
+               u32 val;                                                \
+                                                                       \
+               val = bcm_readl(irq_stat_addr + src * sizeof(u32));     \
+               val &= bcm_readl(irq_mask_addr + src * sizeof(u32));    \
+               pending[--tgt] = val;                                   \
+                                                                       \
+               if (val)                                                \
+                       irqs_pending = true;                            \
+       }                                                               \
+                                                                       \
+       if (!irqs_pending)                                              \
+               return;                                                 \
+                                                                       \
+       while (1) {                                                     \
+               unsigned int to_call = i;                               \
+                                                                       \
+               i = (i + 1) & (width - 1);                              \
+               if (pending[to_call / 32] & (1 << (to_call & 0x1f))) {  \
+                       handle_internal(to_call);                       \
+                       break;                                          \
+               }                                                       \
+       }                                                               \
+}                                                                      \
+                                                                       \
+static void __internal_irq_mask_##width(unsigned int irq)              \
+{                                                                      \
+       u32 val;                                                        \
+       unsigned reg = (irq / 32) ^ (width/32 - 1);                     \
+       unsigned bit = irq & 0x1f;                                      \
+                                                                       \
+       val = bcm_readl(irq_mask_addr + reg * sizeof(u32));             \
+       val &= ~(1 << bit);                                             \
+       bcm_writel(val, irq_mask_addr + reg * sizeof(u32));             \
+}                                                                      \
+                                                                       \
+static void __internal_irq_unmask_##width(unsigned int irq)            \
+{                                                                      \
+       u32 val;                                                        \
+       unsigned reg = (irq / 32) ^ (width/32 - 1);                     \
+       unsigned bit = irq & 0x1f;                                      \
+                                                                       \
+       val = bcm_readl(irq_mask_addr + reg * sizeof(u32));             \
+       val |= (1 << bit);                                              \
+       bcm_writel(val, irq_mask_addr + reg * sizeof(u32));             \
 }
 
-static void __dispatch_internal_64(void)
-{
-       u64 pending;
-       static int i;
-
-       pending = bcm_readq(irq_stat_addr) & bcm_readq(irq_mask_addr);
-
-       if (!pending)
-               return ;
-
-       while (1) {
-               int to_call = i;
-
-               i = (i + 1) & 0x3f;
-               if (pending & (1ull << to_call)) {
-                       handle_internal(to_call);
-                       break;
-               }
-       }
-}
+BUILD_IPIC_INTERNAL(32);
+BUILD_IPIC_INTERNAL(64);
 
 asmlinkage void plat_irq_dispatch(void)
 {
@@ -128,42 +146,6 @@ asmlinkage void plat_irq_dispatch(void)
  * internal IRQs operations: only mask/unmask on PERF irq mask
  * register.
  */
-static void __internal_irq_mask_32(unsigned int irq)
-{
-       u32 mask;
-
-       mask = bcm_readl(irq_mask_addr);
-       mask &= ~(1 << irq);
-       bcm_writel(mask, irq_mask_addr);
-}
-
-static void __internal_irq_mask_64(unsigned int irq)
-{
-       u64 mask;
-
-       mask = bcm_readq(irq_mask_addr);
-       mask &= ~(1ull << irq);
-       bcm_writeq(mask, irq_mask_addr);
-}
-
-static void __internal_irq_unmask_32(unsigned int irq)
-{
-       u32 mask;
-
-       mask = bcm_readl(irq_mask_addr);
-       mask |= (1 << irq);
-       bcm_writel(mask, irq_mask_addr);
-}
-
-static void __internal_irq_unmask_64(unsigned int irq)
-{
-       u64 mask;
-
-       mask = bcm_readq(irq_mask_addr);
-       mask |= (1ull << irq);
-       bcm_writeq(mask, irq_mask_addr);
-}
-
 static void bcm63xx_internal_irq_mask(struct irq_data *d)
 {
        internal_irq_mask(d->irq - IRQ_INTERNAL_BASE);