[patch V3 48/60] x86/apic: Remove pointless arguments from [native_]eoi_write()

[Thomas Gleixner]

Every callsite hands in the same constants which is a pointless exercise
and cannot be optimized by the compiler due to the indirect calls.

Use the constants in the eoi() callbacks and remove the arguments.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Wei Liu <wei.liu@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 arch/x86/hyperv/hv_apic.c             |    6 +++---
 arch/x86/include/asm/apic.h           |   17 +++++++++++------
 arch/x86/kernel/apic/apic.c           |    8 ++++----
 arch/x86/kernel/apic/apic_flat_64.c   |    4 ++--
 arch/x86/kernel/apic/apic_noop.c      |    3 ++-
 arch/x86/kernel/apic/apic_numachip.c  |    4 ++--
 arch/x86/kernel/apic/bigsmp_32.c      |    2 +-
 arch/x86/kernel/apic/probe_32.c       |    2 +-
 arch/x86/kernel/apic/x2apic_cluster.c |    2 +-
 arch/x86/kernel/apic/x2apic_phys.c    |    2 +-
 arch/x86/kernel/apic/x2apic_uv_x.c    |    2 +-
 arch/x86/kernel/kvm.c                 |    6 +++---
 arch/x86/xen/apic.c                   |    7 ++++++-
 13 files changed, 38 insertions(+), 27 deletions(-)

--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -86,14 +86,14 @@ static void hv_apic_write(u32 reg, u32 v
 	}
 }
 
-static void hv_apic_eoi_write(u32 reg, u32 val)
+static void hv_apic_eoi_write(void)
 {
 	struct hv_vp_assist_page *hvp = hv_vp_assist_page[smp_processor_id()];
 
 	if (hvp && (xchg(&hvp->apic_assist, 0) & 0x1))
 		return;
 
-	wrmsr(HV_X64_MSR_EOI, val, 0);
+	wrmsr(HV_X64_MSR_EOI, APIC_EOI_ACK, 0);
 }
 
 static bool cpu_is_self(int cpu)
@@ -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_write(hv_apic_eoi_write);
+		apic_set_eoi_cb(hv_apic_eoi_write);
 		if (!x2apic_enabled()) {
 			apic->read      = hv_apic_read;
 			apic->write     = hv_apic_write;
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -98,6 +98,11 @@ static inline u32 native_apic_mem_read(u
 	return *((volatile u32 *)(APIC_BASE + reg));
 }
 
+static inline void native_apic_mem_eoi(void)
+{
+	native_apic_mem_write(APIC_EOI, APIC_EOI_ACK);
+}
+
 extern void native_apic_icr_write(u32 low, u32 id);
 extern u64 native_apic_icr_read(void);
 
@@ -189,7 +194,7 @@ static inline void native_apic_msr_write
 	wrmsr(APIC_BASE_MSR + (reg >> 4), v, 0);
 }
 
-static inline void native_apic_msr_eoi_write(u32 reg, u32 v)
+static inline void native_apic_msr_eoi(void)
 {
 	__wrmsr(APIC_BASE_MSR + (APIC_EOI >> 4), APIC_EOI_ACK, 0);
 }
@@ -250,8 +255,8 @@ struct irq_data;
  */
 struct apic {
 	/* Hotpath functions first */
-	void	(*eoi_write)(u32 reg, u32 v);
-	void	(*native_eoi_write)(u32 reg, u32 v);
+	void	(*eoi)(void);
+	void	(*native_eoi)(void);
 	void	(*write)(u32 reg, u32 v);
 	u32	(*read)(u32 reg);
 
@@ -351,7 +356,7 @@ static inline void apic_write(u32 reg, u
 
 static inline void apic_eoi(void)
 {
-	apic->eoi_write(APIC_EOI, APIC_EOI_ACK);
+	apic->eoi();
 }
 
 static inline u64 apic_icr_read(void)
@@ -380,7 +385,7 @@ static inline bool apic_id_valid(u32 api
 	return apic_id <= apic->max_apic_id;
 }
 
-extern void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v));
+extern void __init apic_set_eoi_cb(void (*eoi)(void));
 
 #else /* CONFIG_X86_LOCAL_APIC */
 
@@ -391,7 +396,7 @@ static inline u64 apic_icr_read(void) {
 static inline void apic_icr_write(u32 low, u32 high) { }
 static inline void apic_wait_icr_idle(void) { }
 static inline u32 safe_apic_wait_icr_idle(void) { return 0; }
-static inline void apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v)) {}
+static inline void apic_set_eoi_cb(void (*eoi)(void)) {}
 
 #endif /* CONFIG_X86_LOCAL_APIC */
 
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2502,15 +2502,15 @@ void __init acpi_wake_cpu_handler_update
  * interrupts disabled, so we know this does not race with actual APIC driver
  * use.
  */
-void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
+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_write == eoi_write);
-		(*drv)->native_eoi_write = (*drv)->eoi_write;
-		(*drv)->eoi_write = eoi_write;
+		WARN_ON((*drv)->eoi == eoi);
+		(*drv)->native_eoi = (*drv)->eoi;
+		(*drv)->eoi = eoi;
 	}
 }
 
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -106,7 +106,7 @@ static struct apic apic_flat __ro_after_
 
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
-	.eoi_write			= native_apic_mem_write,
+	.eoi				= native_apic_mem_eoi,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= apic_mem_wait_icr_idle,
@@ -182,7 +182,7 @@ static struct apic apic_physflat __ro_af
 
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
-	.eoi_write			= native_apic_mem_write,
+	.eoi				= native_apic_mem_eoi,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= apic_mem_wait_icr_idle,
--- a/arch/x86/kernel/apic/apic_noop.c
+++ b/arch/x86/kernel/apic/apic_noop.c
@@ -29,6 +29,7 @@ static int noop_wakeup_secondary_cpu(int
 static u64 noop_apic_icr_read(void) { return 0; }
 static int noop_phys_pkg_id(int cpuid_apic, int index_msb) { return 0; }
 static unsigned int noop_get_apic_id(unsigned long x) { return 0; }
+static void noop_apic_eoi(void) { }
 
 static u32 noop_apic_read(u32 reg)
 {
@@ -71,7 +72,7 @@ struct apic apic_noop __ro_after_init =
 
 	.read				= noop_apic_read,
 	.write				= noop_apic_write,
-	.eoi_write			= noop_apic_write,
+	.eoi				= noop_apic_eoi,
 	.icr_read			= noop_apic_icr_read,
 	.icr_write			= noop_apic_icr_write,
 };
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -247,7 +247,7 @@ static const struct apic apic_numachip1
 
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
-	.eoi_write			= native_apic_mem_write,
+	.eoi				= native_apic_mem_eoi,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 };
@@ -284,7 +284,7 @@ static const struct apic apic_numachip2
 
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
-	.eoi_write			= native_apic_mem_write,
+	.eoi				= native_apic_mem_eoi,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 };
--- a/arch/x86/kernel/apic/bigsmp_32.c
+++ b/arch/x86/kernel/apic/bigsmp_32.c
@@ -105,7 +105,7 @@ static struct apic apic_bigsmp __ro_afte
 
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
-	.eoi_write			= native_apic_mem_write,
+	.eoi				= native_apic_mem_eoi,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= apic_mem_wait_icr_idle,
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -60,7 +60,7 @@ static struct apic apic_default __ro_aft
 
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
-	.eoi_write			= native_apic_mem_write,
+	.eoi				= native_apic_mem_eoi,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= apic_mem_wait_icr_idle,
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -254,7 +254,7 @@ static struct apic apic_x2apic_cluster _
 
 	.read				= native_apic_msr_read,
 	.write				= native_apic_msr_write,
-	.eoi_write			= native_apic_msr_eoi_write,
+	.eoi				= native_apic_msr_eoi,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
 };
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -169,7 +169,7 @@ static struct apic apic_x2apic_phys __ro
 
 	.read				= native_apic_msr_read,
 	.write				= native_apic_msr_write,
-	.eoi_write			= native_apic_msr_eoi_write,
+	.eoi				= native_apic_msr_eoi,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
 };
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -831,7 +831,7 @@ static struct apic apic_x2apic_uv_x __ro
 
 	.read				= native_apic_msr_read,
 	.write				= native_apic_msr_write,
-	.eoi_write			= native_apic_msr_eoi_write,
+	.eoi				= native_apic_msr_eoi,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
 };
--- a/arch/x86/kernel/kvm.c
+++ b/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(u32 reg, u32 val)
+static notrace void kvm_guest_apic_eoi_write(void)
 {
 	/**
 	 * This relies on __test_and_clear_bit to modify the memory
@@ -343,7 +343,7 @@ static notrace void kvm_guest_apic_eoi_w
 	 */
 	if (__test_and_clear_bit(KVM_PV_EOI_BIT, this_cpu_ptr(&kvm_apic_eoi)))
 		return;
-	apic->native_eoi_write(APIC_EOI, APIC_EOI_ACK);
+	apic->native_eoi();
 }
 
 static void kvm_guest_cpu_init(void)
@@ -825,7 +825,7 @@ static void __init kvm_guest_init(void)
 	}
 
 	if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
-		apic_set_eoi_write(kvm_guest_apic_eoi_write);
+		apic_set_eoi_cb(kvm_guest_apic_eoi_write);
 
 	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
 		static_branch_enable(&kvm_async_pf_enabled);
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -81,6 +81,11 @@ static void xen_apic_write(u32 reg, u32
 	WARN(1,"register: %x, value: %x\n", reg, val);
 }
 
+static void xen_apic_eoi(void)
+{
+	WARN_ON_ONCE(1);
+}
+
 static u64 xen_apic_icr_read(void)
 {
 	return 0;
@@ -147,7 +152,7 @@ static struct apic xen_pv_apic = {
 #endif
 	.read				= xen_apic_read,
 	.write				= xen_apic_write,
-	.eoi_write			= xen_apic_write,
+	.eoi				= xen_apic_eoi,
 
 	.icr_read 			= xen_apic_icr_read,
 	.icr_write 			= xen_apic_icr_write,