Segher Boessenkool wrote:

quoted

 config GAMECUBE_COMMON
     bool
     select NOT_COHERENT_CACHE
+    select FLIPPER_PIC

Maybe using FLIPPER (or GAMECUBE_FLIPPER) instead of GAMECUBE_COMMON
is a good name?

I'd prefer to not use a name that implies a specific hardware to describe two (mostly) similar but different hardwares.

quoted

+#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt

Unused

Nope. It is used via the pr_{err,info,...} macros.

quoted

+/*
+ * Each interrupt has a corresponding bit in both
+ * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
+ *
+ * Enabling/disabling an interrupt line involves asserting/clearing
+ * the corresponding bit in IMR. ACK'ing a request simply involves
+ * asserting the corresponding bit in ICR.
+ */

quoted

+static void flipper_pic_ack(unsigned int virq)
+{
+    int irq = virq_to_hw(virq);
+    void __iomem *io_base = get_irq_chip_data(virq);
+
+    set_bit(irq, io_base + FLIPPER_ICR);
+}

So it should be a simple write instead of an RMW here, right?
As it is you are ACKing _all_ IRQs as far as I can see.

No, it acks just a single IRQ.
But the simple write idea may work. I need to check if writing 0s causes no harm (which IIRC is true).

quoted

+unsigned int flipper_pic_get_irq(void)
+{
+    void __iomem *io_base = flipper_irq_host->host_data;
+    int irq;
+    u32 irq_status;
+
+    irq_status = in_be32(io_base + FLIPPER_ICR) &
+             in_be32(io_base + FLIPPER_IMR);
+    if (irq_status == 0)
+        return -1;    /* no more IRQs pending */
+
+    __asm__ __volatile__("cntlzw %0,%1" : "=r"(irq) : "r"(irq_status));
+    return irq_linear_revmap(flipper_irq_host, 31 - irq);
+}

There are generic macros for this kind of thing, no need for asm.  ffs()
or something.

__ffs() matches exactly that. Thanks.

Cheers,
Albert