sparc32: introduce build_device_irq

build_device_irq() is used to encapsulate the plaform
specific details when we build an irq.
For now the default is a simple 1:1 but sun4d differs.
This patch refactors functionality - but does not change
the existing functionality.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 51 insertions, 0 deletions

diff --git a/arch/sparc/kernel/sun4d_irq.c b/arch/sparc/kernel/sun4d_irq.c
index fc1c22f121f..77b4a899271 100644
--- a/arch/sparc/kernel/sun4d_irq.c
+++ b/arch/sparc/kernel/sun4d_irq.c
@@ -440,6 +440,56 @@ static void __init sun4d_load_profile_irqs(void)
         }
 }
 
+unsigned int sun4d_build_device_irq(struct platform_device *op,
+                                    unsigned int real_irq)
+{
+        static int pil_to_sbus[] = {
+                0, 0, 1, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 0,
+        };
+        struct device_node *dp = op->dev.of_node;
+        struct device_node *io_unit, *sbi = dp->parent;
+        const struct linux_prom_registers *regs;
+        int board, slot;
+        int sbusl;
+
+        while (sbi) {
+                if (!strcmp(sbi->name, "sbi"))
+                        break;
+
+                sbi = sbi->parent;
+        }
+        if (!sbi)
+                goto err_out;
+
+        regs = of_get_property(dp, "reg", NULL);
+        if (!regs)
+                goto err_out;
+
+        slot = regs->which_io;
+
+        /*
+         *  If SBI's parent is not io-unit or the io-unit lacks
+         * a "board#" property, something is very wrong.
+         */
+        if (!sbi->parent || strcmp(sbi->parent->name, "io-unit")) {
+                printk("%s: Error, parent is not io-unit.\n", sbi->full_name);
+                goto err_out;
+        }
+        io_unit = sbi->parent;
+        board = of_getintprop_default(io_unit, "board#", -1);
+        if (board == -1) {
+                printk("%s: Error, lacks board# property.\n", io_unit->full_name);
+                goto err_out;
+        }
+
+        sbusl = pil_to_sbus[real_irq];
+        if (sbusl)
+                return (((board + 1) << 5) + (sbusl << 2) + slot);
+
+err_out:
+        return real_irq;
+}
+
 static void __init sun4d_fixup_trap_table(void)
 {
 #ifdef CONFIG_SMP
@@ -559,6 +609,7 @@ void __init sun4d_init_IRQ(void)
         BTFIXUPSET_CALL(load_profile_irq, sun4d_load_profile_irq, BTFIXUPCALL_NORM);
 
         sparc_irq_config.init_timers = sun4d_init_timers;
+        sparc_irq_config.build_device_irq = sun4d_build_device_irq;
 
 #ifdef CONFIG_SMP
         BTFIXUPSET_CALL(set_cpu_int, sun4d_set_cpu_int, BTFIXUPCALL_NORM);