x86: dt: Use linear irq domain for ioapic(s)

The former conversion to irq_domain_add_legacy() did not fully work
since we miss the irq decs for NR_IRQS_LEGACY+.

Ideally we could use irq_domain_add_simple() or the no-map variant (and
program the virq <-> line mapping directly into ioapic) but this would
require a different irq lookup in "do_IRQ()" and won't work with ACPI
without changes. So this is probably easiest for everyone.

Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Link: http://lkml.kernel.org/r/20120813202304.GA3529@breakpoint.cc
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 3ae2ced4a874ac930c0fd6563820dc3a482d75d2..b1581527a236a2f1b0d9657f14f13b471f7725fb 100644 (file)
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -342,6 +342,47 @@ const struct irq_domain_ops ioapic_irq_domain_ops = {
        .xlate = ioapic_xlate,
 };
 
+static void dt_add_ioapic_domain(unsigned int ioapic_num,
+               struct device_node *np)
+{
+       struct irq_domain *id;
+       struct mp_ioapic_gsi *gsi_cfg;
+       int ret;
+       int num;
+
+       gsi_cfg = mp_ioapic_gsi_routing(ioapic_num);
+       num = gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
+
+       id = irq_domain_add_linear(np, num, &ioapic_irq_domain_ops,
+                       (void *)ioapic_num);
+       BUG_ON(!id);
+       if (gsi_cfg->gsi_base == 0) {
+               /*
+                * The first NR_IRQS_LEGACY irq descs are allocated in
+                * early_irq_init() and need just a mapping. The
+                * remaining irqs need both. All of them are preallocated
+                * and assigned so we can keep the 1:1 mapping which the ioapic
+                * is having.
+                */
+               ret = irq_domain_associate_many(id, 0, 0, NR_IRQS_LEGACY);
+               if (ret)
+                       pr_err("Error mapping legacy IRQs: %d\n", ret);
+
+               if (num > NR_IRQS_LEGACY) {
+                       ret = irq_create_strict_mappings(id, NR_IRQS_LEGACY,
+                                       NR_IRQS_LEGACY, num - NR_IRQS_LEGACY);
+                       if (ret)
+                               pr_err("Error creating mapping for the "
+                                               "remaining IRQs: %d\n", ret);
+               }
+               irq_set_default_host(id);
+       } else {
+               ret = irq_create_strict_mappings(id, gsi_cfg->gsi_base, 0, num);
+               if (ret)
+                       pr_err("Error creating IRQ mapping: %d\n", ret);
+       }
+}
+
 static void __init ioapic_add_ofnode(struct device_node *np)
 {
        struct resource r;
@@ -356,15 +397,7 @@ static void __init ioapic_add_ofnode(struct device_node *np)
 
        for (i = 0; i < nr_ioapics; i++) {
                if (r.start == mpc_ioapic_addr(i)) {
-                       struct irq_domain *id;
-                       struct mp_ioapic_gsi *gsi_cfg;
-
-                       gsi_cfg = mp_ioapic_gsi_routing(i);
-
-                       id = irq_domain_add_legacy(np, 32, gsi_cfg->gsi_base, 0,
-                                                  &ioapic_irq_domain_ops,
-                                                  (void*)i);
-                       BUG_ON(!id);
+                       dt_add_ioapic_domain(i, np);
                        return;
                }
        }