x86/apic: Add select() method on vector irqdomain

This will be used to select the irqdomain for I/OAPIC and HPET.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

diff --git a/arch/x86/include/asm/irqdomain.h b/arch/x86/include/asm/irqdomain.h
index cd684d45cb5fadd6d225be2c6a40b65d85da8c3e..125c23b7bad394b61c06f1266330149e3a975e0f 100644 (file)
--- a/arch/x86/include/asm/irqdomain.h
+++ b/arch/x86/include/asm/irqdomain.h
@@ -12,6 +12,9 @@ enum {
        X86_IRQ_ALLOC_LEGACY                            = 0x2,
 };
 
+extern int x86_fwspec_is_ioapic(struct irq_fwspec *fwspec);
+extern int x86_fwspec_is_hpet(struct irq_fwspec *fwspec);
+
 extern struct irq_domain *x86_vector_domain;
 
 extern void init_irq_alloc_info(struct irq_alloc_info *info,

diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index bb2e2a2488a55ccdc85d5f50b524e8a2d2456b3b..51ab81fcb260e44155d1d0921c9f8143c8a3eee8 100644 (file)
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -636,7 +636,54 @@ static void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d,
 }
 #endif
 
+int x86_fwspec_is_ioapic(struct irq_fwspec *fwspec)
+{
+       if (fwspec->param_count != 1)
+               return 0;
+
+       if (is_fwnode_irqchip(fwspec->fwnode)) {
+               const char *fwname = fwnode_get_name(fwspec->fwnode);
+               return fwname && !strncmp(fwname, "IO-APIC-", 8) &&
+                       simple_strtol(fwname+8, NULL, 10) == fwspec->param[0];
+       }
+       return to_of_node(fwspec->fwnode) &&
+               of_device_is_compatible(to_of_node(fwspec->fwnode),
+                                       "intel,ce4100-ioapic");
+}
+
+int x86_fwspec_is_hpet(struct irq_fwspec *fwspec)
+{
+       if (fwspec->param_count != 1)
+               return 0;
+
+       if (is_fwnode_irqchip(fwspec->fwnode)) {
+               const char *fwname = fwnode_get_name(fwspec->fwnode);
+               return fwname && !strncmp(fwname, "HPET-MSI-", 9) &&
+                       simple_strtol(fwname+9, NULL, 10) == fwspec->param[0];
+       }
+       return 0;
+}
+
+static int x86_vector_select(struct irq_domain *d, struct irq_fwspec *fwspec,
+                            enum irq_domain_bus_token bus_token)
+{
+       /*
+        * HPET and I/OAPIC drivers use irq_find_matching_irqdomain()
+        * to find their parent irqdomain. For x86_vector_domain to be
+        * suitable, all CPUs in the system must be reachable by its
+        * x86_vector_msi_compose_msg() function. Which is only true
+        * in !x2apic mode, or in x2apic physical mode if APIC IDs were
+        * restricted to 8 or 15 bits at boot time. In those cases,
+        * 1<<15 will *not* be a valid APIC ID.
+        */
+       if (apic->apic_id_valid(1<<15))
+               return 0;
+
+       return x86_fwspec_is_ioapic(fwspec) || x86_fwspec_is_hpet(fwspec);
+}
+
 static const struct irq_domain_ops x86_vector_domain_ops = {
+       .select         = x86_vector_select,
        .alloc          = x86_vector_alloc_irqs,
        .free           = x86_vector_free_irqs,
        .activate       = x86_vector_activate,