x86, hpet: Introduce x86_msi_ops.setup_hpet_msi

This function pointer can be overwritten by the IRQ
remapping code. The irq_remapping_enabled check can be
removed from default_setup_hpet_msi.
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/include/asm/hpet.h

@@ -80,9 +80,9 @@ extern void hpet_msi_write(struct hpet_dev *hdev, struct msi_msg *msg);
 extern void hpet_msi_read(struct hpet_dev *hdev, struct msi_msg *msg);
 
 #ifdef CONFIG_PCI_MSI
-extern int arch_setup_hpet_msi(unsigned int irq, unsigned int id);
+extern int default_setup_hpet_msi(unsigned int irq, unsigned int id);
 #else
-static inline int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
+static inline int default_setup_hpet_msi(unsigned int irq, unsigned int id)
 {
 	return -EINVAL;
 }
@@ -111,6 +111,7 @@ extern void hpet_unregister_irq_handler(rtc_irq_handler handler);
 static inline int hpet_enable(void) { return 0; }
 static inline int is_hpet_enabled(void) { return 0; }
 #define hpet_readl(a) 0
+#define default_setup_hpet_msi	NULL
 
 #endif
 #endif /* _ASM_X86_HPET_H */

arch/x86/include/asm/x86_init.h

@@ -187,6 +187,7 @@ struct x86_msi_ops {
 	void (*teardown_msi_irq)(unsigned int irq);
 	void (*teardown_msi_irqs)(struct pci_dev *dev);
 	void (*restore_msi_irqs)(struct pci_dev *dev, int irq);
+	int  (*setup_hpet_msi)(unsigned int irq, unsigned int id);
 };
 
 struct x86_io_apic_ops {

arch/x86/kernel/apic/io_apic.c

@@ -3399,18 +3399,12 @@ static struct irq_chip hpet_msi_type = {
 	.irq_retrigger = ioapic_retrigger_irq,
 };
 
-int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
+int default_setup_hpet_msi(unsigned int irq, unsigned int id)
 {
 	struct irq_chip *chip = &hpet_msi_type;
 	struct msi_msg msg;
 	int ret;
 
-	if (irq_remapping_enabled) {
-		ret = setup_hpet_msi_remapped(irq, id);
-		if (ret)
-			return ret;
-	}
-
 	ret = msi_compose_msg(NULL, irq, &msg, id);
 	if (ret < 0)
 		return ret;

arch/x86/kernel/hpet.c

@@ -478,7 +478,7 @@ static int hpet_msi_next_event(unsigned long delta,
 
 static int hpet_setup_msi_irq(unsigned int irq)
 {
-	if (arch_setup_hpet_msi(irq, hpet_blockid)) {
+	if (x86_msi.setup_hpet_msi(irq, hpet_blockid)) {
 		destroy_irq(irq);
 		return -EINVAL;
 	}

arch/x86/kernel/x86_init.c

@@ -19,6 +19,7 @@
 #include <asm/time.h>
 #include <asm/irq.h>
 #include <asm/io_apic.h>
+#include <asm/hpet.h>
 #include <asm/pat.h>
 #include <asm/tsc.h>
 #include <asm/iommu.h>
@@ -115,6 +116,7 @@ struct x86_msi_ops x86_msi = {
 	.teardown_msi_irq	= native_teardown_msi_irq,
 	.teardown_msi_irqs	= default_teardown_msi_irqs,
 	.restore_msi_irqs	= default_restore_msi_irqs,
+	.setup_hpet_msi		= default_setup_hpet_msi,
 };
 
 struct x86_io_apic_ops x86_io_apic_ops = {

drivers/iommu/irq_remapping.c

@@ -37,6 +37,7 @@ static void irq_remapping_disable_io_apic(void)
 static void __init irq_remapping_modify_x86_ops(void)
 {
 	x86_io_apic_ops.disable		= irq_remapping_disable_io_apic;
+	x86_msi.setup_hpet_msi		= setup_hpet_msi_remapped;
 }
 
 static __init int setup_nointremap(char *str)