x86/apic: Replace acpi_wake_cpu_handler_update() and apic_set_eoi_cb()

Switch them over to apic_update_callback() and remove the code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)

arch/x86/hyperv/hv_apic.c

@@ -310,7 +310,7 @@ void __init hv_apic_init(void)
 		 * lazy EOI when available, but the same accessor works for
 		 * both xapic and x2apic because the field layout is the same.
 		 */
-		apic_set_eoi_cb(hv_apic_eoi_write);
+		apic_update_callback(eoi, hv_apic_eoi_write);
 		if (!x2apic_enabled()) {
 			apic->read      = hv_apic_read;
 			apic->write     = hv_apic_write;

arch/x86/hyperv/hv_vtl.c

@@ -222,7 +222,7 @@ static int __init hv_vtl_early_init(void)
 			  "Please add 'noxsave' to the kernel command line.\n");
 
 	real_mode_header = &hv_vtl_real_mode_header;
-	apic->wakeup_secondary_cpu_64 = hv_vtl_wakeup_secondary_cpu;
+	apic_update_callback(wakeup_secondary_cpu_64, hv_vtl_wakeup_secondary_cpu);
 
 	return 0;
 }

arch/x86/include/asm/apic.h

@@ -417,8 +417,6 @@ static inline bool apic_id_valid(u32 apic_id)
 	return apic_id <= apic->max_apic_id;
 }
 
-extern void __init apic_set_eoi_cb(void (*eoi)(void));
-
 #else /* CONFIG_X86_LOCAL_APIC */
 
 static inline u32 apic_read(u32 reg) { return 0; }
@@ -478,7 +476,6 @@ static inline unsigned int read_apic_id(void)
 
 #ifdef CONFIG_X86_64
 typedef int (*wakeup_cpu_handler)(int apicid, unsigned long start_eip);
-extern void acpi_wake_cpu_handler_update(wakeup_cpu_handler handler);
 extern int default_acpi_madt_oem_check(char *, char *);
 extern void x86_64_probe_apic(void);
 #else

arch/x86/kernel/acpi/boot.c

@@ -1174,7 +1174,7 @@ static int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
 
 	acpi_mp_wake_mailbox_paddr = mp_wake->base_address;
 
-	acpi_wake_cpu_handler_update(acpi_wakeup_cpu);
+	apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
 
 	return 0;
 }

arch/x86/kernel/apic/init.c

@@ -55,30 +55,3 @@ void __init apic_install_driver(struct apic *driver)
 
 	pr_info("Switched APIC routing to: %s\n", driver->name);
 }
-
-#ifdef CONFIG_X86_64
-void __init acpi_wake_cpu_handler_update(wakeup_cpu_handler handler)
-{
-	struct apic **drv;
-
-	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++)
-		(*drv)->wakeup_secondary_cpu_64 = handler;
-}
-#endif
-
-/*
- * Override the generic EOI implementation with an optimized version.
- * Only called during early boot when only one CPU is active and with
- * interrupts disabled, so we know this does not race with actual APIC driver
- * use.
- */
-void __init apic_set_eoi_cb(void (*eoi)(void))
-{
-	struct apic **drv;
-
-	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
-		/* Should happen once for each apic */
-		WARN_ON((*drv)->eoi == eoi);
-		(*drv)->eoi = eoi;
-	}
-}

arch/x86/kernel/kvm.c

@@ -332,7 +332,7 @@ static void kvm_register_steal_time(void)
 
 static DEFINE_PER_CPU_DECRYPTED(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED;
 
-static notrace void kvm_guest_apic_eoi_write(void)
+static notrace __maybe_unused void kvm_guest_apic_eoi_write(void)
 {
 	/**
 	 * This relies on __test_and_clear_bit to modify the memory
@@ -825,7 +825,7 @@ static void __init kvm_guest_init(void)
 	}
 
 	if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
-		apic_set_eoi_cb(kvm_guest_apic_eoi_write);
+		apic_update_callback(eoi, kvm_guest_apic_eoi_write);
 
 	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
 		static_branch_enable(&kvm_async_pf_enabled);