x86/local_apic.c: Thermal interrupt support: Additional style fixes

Rename handler function type 'lapic_thermal_handle_function' to the
shorter 'lapic_thermal_handler_t'.  Move it closer to the function
declaration block where it is used.  Make it a true function type (no
pointer) and add explicit pointer marks on usage.

Rename 'lapic_thermal_function_value' to the more immediately clear
'lapic_thermal_function_arg'.  In lapic_thermal_enable(), use 'func_arg'
as the argument name for the handler argument, which at least refers to
function 'func', rather than the generic 'value'.

Finally, rename the global handler variable from
'lapic_thermal_function_ptr' to the shorter 'lapic_thermal_function'
(dynamic functions can be referenced only through a pointer).

MFC with:       87ba088fa310 ("x86/local_apic.c: Add support for installing a thermal interrupt handler")
Sponsored by:   The FreeBSD Foundation

2 files changed, 15 insertions, 13 deletions

diff --git a/sys/x86/include/apicvar.h b/sys/x86/include/apicvar.h
index 66d53bbf7e5d..54ea5bc655e5 100644
--- a/sys/x86/include/apicvar.h
+++ b/sys/x86/include/apicvar.h
@@ -199,7 +199,6 @@ extern int *apic_cpuids;
 extern void (*ipi_vectored)(u_int, int);
 
 typedef struct ioapic *ioapic_drv_t;
-typedef void (*lapic_thermal_handle_function)(int, void *);
 
 void	apic_register_enumerator(struct apic_enumerator *enumerator);
 ioapic_drv_t	ioapic_create(vm_paddr_t addr, int32_t apic_id, int intbase);
@@ -215,6 +214,9 @@ int	ioapic_set_triggermode(ioapic_drv_t cookie, u_int pin,
 	    enum intr_trigger trigger);
 int	ioapic_set_smi(ioapic_drv_t cookie, u_int pin);
 
+/* First argument: 'cpuid' from 'struct pcpu', second: Opaque cookie. */
+typedef void lapic_thermal_handler_t(int, void *);
+
 void	lapic_create(u_int apic_id, int boot_cpu);
 void	lapic_init(vm_paddr_t addr);
 void	lapic_xapic_mode(void);
@@ -234,7 +236,7 @@ void	apic_enable_vector(u_int apic_id, u_int vector);
 void	apic_disable_vector(u_int apic_id, u_int vector);
 void	apic_free_vector(u_int apic_id, u_int vector, u_int irq);
 void	lapic_calibrate_timer(void);
-void	lapic_enable_thermal(lapic_thermal_handle_function thermfunc, void *value);
+void	lapic_enable_thermal(lapic_thermal_handler_t *func, void *func_arg);
 void	lapic_disable_thermal(void);
 int	lapic_enable_pcint(void);
 void	lapic_disable_pcint(void);
diff --git a/sys/x86/x86/local_apic.c b/sys/x86/x86/local_apic.c
index 08748a1fe7c2..9e1c1d70aea7 100644
--- a/sys/x86/x86/local_apic.c
+++ b/sys/x86/x86/local_apic.c
@@ -314,8 +314,8 @@ static uint64_t lapic_ipi_wait_mult;
 static int __read_mostly lapic_ds_idle_timeout = 1000000;
 #endif
 unsigned int max_apic_id;
-static void *lapic_thermal_function_value;
-static lapic_thermal_handle_function lapic_thermal_function_ptr;
+static lapic_thermal_handler_t *lapic_thermal_function;
+static void *lapic_thermal_function_arg;
 static int pcint_refcnt = 0;
 
 SYSCTL_NODE(_hw, OID_AUTO, apic, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
@@ -1642,13 +1642,13 @@ lapic_enable_mca_elvt(void)
 void
 lapic_handle_thermal(void)
 {
-	lapic_thermal_handle_function func;
+	lapic_thermal_handler_t *func;
 
-	func = (lapic_thermal_handle_function)atomic_load_acq_ptr(
-	    (void *)&lapic_thermal_function_ptr);
+	func = (lapic_thermal_handler_t *)atomic_load_acq_ptr(
+	    (uintptr_t *)&lapic_thermal_function);
 
 	if (func != NULL)
-		func(PCPU_GET(cpuid), lapic_thermal_function_value);
+		func(PCPU_GET(cpuid), lapic_thermal_function_arg);
 
 	lapic_eoi();
 }
@@ -1664,7 +1664,7 @@ lapic_update_thermal(void *dummy __unused)
 }
 
 void
-lapic_enable_thermal(lapic_thermal_handle_function thermfunc, void *value)
+lapic_enable_thermal(lapic_thermal_handler_t *func, void *func_arg)
 {
 #ifdef DEV_ATPIC
 	/* Fail if the local APIC is not present. */
@@ -1672,9 +1672,9 @@ lapic_enable_thermal(lapic_thermal_handle_function thermfunc, void *value)
 		return;
 #endif
 
-	lapic_thermal_function_value = value;
-	atomic_store_rel_ptr((uintptr_t *)&lapic_thermal_function_ptr,
-	    (uintptr_t)thermfunc);
+	lapic_thermal_function_arg = func_arg;
+	atomic_store_rel_ptr((uintptr_t *)&lapic_thermal_function,
+	    (uintptr_t)func);
 
 	lvts[APIC_LVT_THERMAL].lvt_masked = 0;
 
@@ -1698,7 +1698,7 @@ lapic_disable_thermal(void)
 #endif
 	smp_rendezvous(NULL, lapic_update_thermal, NULL, NULL);
 
-	atomic_store_rel_ptr((uintptr_t *)&lapic_thermal_function_ptr,
+	atomic_store_rel_ptr((uintptr_t *)&lapic_thermal_function,
 	    (uintptr_t)NULL);
 }