x86/apic: Allow apic::safe_wait_icr_idle() to be NULL

Remove tons of NOOP callbacks by making the invocation of
safe_wait_icr_idle() conditional in the inline wrapper.

Will be replaced by a static_call_cond() later.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
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)

7 files changed, 1 insertions, 30 deletions

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 397cd5ff2ebc..dd0a05dbe980 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -206,12 +206,6 @@ static inline u32 native_apic_msr_read(u32 reg)
 	return (u32)msr;
 }
 
-static inline u32 native_safe_x2apic_wait_icr_idle(void)
-{
-	/* no need to wait for icr idle in x2apic */
-	return 0;
-}
-
 static inline void native_x2apic_icr_write(u32 low, u32 id)
 {
 	wrmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), ((__u64) id) << 32 | low);
@@ -376,7 +370,7 @@ static inline void apic_wait_icr_idle(void)
 
 static inline u32 safe_apic_wait_icr_idle(void)
 {
-	return apic->safe_wait_icr_idle();
+	return apic->safe_wait_icr_idle ? apic->safe_wait_icr_idle() : 0;
 }
 
 extern void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v));
diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c
index ef31a2e829f1..36c1e287ad05 100644
--- a/arch/x86/kernel/apic/apic_noop.c
+++ b/arch/x86/kernel/apic/apic_noop.c
@@ -27,11 +27,6 @@ static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
 	return -1;
 }
 
-static u32 noop_safe_apic_wait_icr_idle(void)
-{
-	return 0;
-}
-
 static u64 noop_apic_icr_read(void)
 {
 	return 0;
@@ -104,5 +99,4 @@ struct apic apic_noop __ro_after_init = {
 	.eoi_write			= noop_apic_write,
 	.icr_read			= noop_apic_icr_read,
 	.icr_write			= noop_apic_icr_write,
-	.safe_wait_icr_idle		= noop_safe_apic_wait_icr_idle,
 };
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index 647ed774b346..e879dbb57696 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -223,12 +223,6 @@ static int numachip2_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 	return 1;
 }
 
-/* APIC NMI IPIs are queued */
-static u32 numachip_safe_apic_wait_icr_idle(void)
-{
-	return 0;
-}
-
 static const struct apic apic_numachip1 __refconst = {
 	.name				= "NumaConnect system",
 	.probe				= numachip1_probe,
@@ -264,7 +258,6 @@ static const struct apic apic_numachip1 __refconst = {
 	.eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
-	.safe_wait_icr_idle		= numachip_safe_apic_wait_icr_idle,
 };
 
 apic_driver(apic_numachip1);
@@ -304,7 +297,6 @@ static const struct apic apic_numachip2 __refconst = {
 	.eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
-	.safe_wait_icr_idle		= numachip_safe_apic_wait_icr_idle,
 };
 
 apic_driver(apic_numachip2);
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index 7ceef70312b5..355da47e3d3a 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -266,7 +266,6 @@ static struct apic apic_x2apic_cluster __ro_after_init = {
 	.eoi_write			= native_apic_msr_eoi_write,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
-	.safe_wait_icr_idle		= native_safe_x2apic_wait_icr_idle,
 };
 
 apic_driver(apic_x2apic_cluster);
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index c1ab67859134..2c9a884efd6b 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -180,7 +180,6 @@ static struct apic apic_x2apic_phys __ro_after_init = {
 	.eoi_write			= native_apic_msr_eoi_write,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
-	.safe_wait_icr_idle		= native_safe_x2apic_wait_icr_idle,
 };
 
 apic_driver(apic_x2apic_phys);
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 5cb68f657f79..f532c5856dbb 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -854,7 +854,6 @@ static struct apic apic_x2apic_uv_x __ro_after_init = {
 	.eoi_write			= native_apic_msr_eoi_write,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
-	.safe_wait_icr_idle		= native_safe_x2apic_wait_icr_idle,
 };
 
 #define	UVH_RH_GAM_ALIAS210_REDIRECT_CONFIG_LENGTH	3
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index e709bf0be86a..0f71b2e79c76 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -92,11 +92,6 @@ static void xen_apic_icr_write(u32 low, u32 id)
 	WARN_ON(1);
 }
 
-static u32 xen_safe_apic_wait_icr_idle(void)
-{
-        return 0;
-}
-
 static int xen_apic_probe_pv(void)
 {
 	if (xen_pv_domain())
@@ -161,7 +156,6 @@ static struct apic xen_pv_apic = {
 
 	.icr_read 			= xen_apic_icr_read,
 	.icr_write 			= xen_apic_icr_write,
-	.safe_wait_icr_idle 		= xen_safe_apic_wait_icr_idle,
 };
 
 static void __init xen_apic_check(void)