[PATCH v3 23/35] x86/apic: Add select() method on vector irqdomain

David Woodhouse
2020-10-24T21:36:26Z

From: David Woodhouse <dwmw@amazon.co.uk>

This will be used to select the irqdomain for I/O-APIC and HPET.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/irqdomain.h | 3 +++
arch/x86/kernel/apic/vector.c | 43 ++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+)

diff --git a/arch/x86/include/asm/irqdomain.h b/arch/x86/include/asm/irqdomain.h
index cd684d45cb5f..125c23b7bad3 100644
--- 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 bb2e2a2488a5..b9b05caa28a4 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -636,7 +636,50 @@ 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 cannot be parented in the vector domain
+ * if IRQ remapping is enabled. APIC IDs above 15 bits are
+ * only permitted if IRQ remapping is enabled, so check that.
+ */
+ if (apic->apic_id_valid(32768))
+ 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,