Follow the lead of mips64 and make cpu_idle_cycle() just call the

indirect pointer itself and provide an initializer for that going
to the default "just enable interrupts and halt" path.

ok kettenis@

diff --git a/sys/arch/amd64/amd64/locore.S b/sys/arch/amd64/amd64/locore.S
index c2536e7..2046f09 100644 (file)
--- a/sys/arch/amd64/amd64/locore.S
+++ b/sys/arch/amd64/amd64/locore.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: locore.S,v 1.137 2023/07/25 06:48:37 guenther Exp $   */
+/*     $OpenBSD: locore.S,v 1.138 2023/07/27 00:28:24 guenther Exp $   */
 /*     $NetBSD: locore.S,v 1.13 2004/03/25 18:33:17 drochner Exp $     */
 
 /*
@@ -473,21 +473,17 @@ bogus_proc_pmap:
 #endif /* DIAGNOSTIC */
 END(cpu_switchto)
 
-/* placed here for correct static branch prediction in cpu_idle_* */
 NENTRY(retpoline_rax)
        JMP_RETPOLINE(rax)
 
-ENTRY(cpu_idle_cycle)
-       RETGUARD_SETUP(cpu_idle_cycle, r11)
-       movq    cpu_idle_cycle_fcn,%rax
-       cmpq    $0,%rax
-       jne     retpoline_rax
+ENTRY(cpu_idle_cycle_hlt)
+       RETGUARD_SETUP(cpu_idle_cycle_hlt, r11)
        sti
        hlt
-       RETGUARD_CHECK(cpu_idle_cycle, r11)
+       RETGUARD_CHECK(cpu_idle_cycle_hlt, r11)
        ret
        lfence
-END(cpu_idle_cycle)
+END(cpu_idle_cycle_hlt)
 
 /*
  * savectx(struct pcb *pcb);

diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index ddbeedb..453de13 100644 (file)
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: machdep.c,v 1.285 2023/07/10 03:32:10 guenther Exp $  */
+/*     $OpenBSD: machdep.c,v 1.286 2023/07/27 00:28:25 guenther Exp $  */
 /*     $NetBSD: machdep.c,v 1.3 2003/05/07 22:58:18 fvdl Exp $ */
 
 /*-
@@ -160,7 +160,8 @@ char machine[] = MACHINE;
 /*
  * switchto vectors
  */
-void (*cpu_idle_cycle_fcn)(void) = NULL;
+void cpu_idle_cycle_hlt(void);
+void (*cpu_idle_cycle_fcn)(void) = &cpu_idle_cycle_hlt;
 
 /* the following is used externally for concurrent handlers */
 int setperf_prio = 0;

diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h
index b5784ab..cf32288 100644 (file)
--- a/sys/arch/amd64/include/cpu.h
+++ b/sys/arch/amd64/include/cpu.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: cpu.h,v 1.157 2023/07/25 18:16:19 cheloha Exp $       */
+/*     $OpenBSD: cpu.h,v 1.158 2023/07/27 00:28:24 guenther Exp $      */
 /*     $NetBSD: cpu.h,v 1.1 2003/04/26 18:39:39 fvdl Exp $     */
 
 /*-
@@ -406,6 +406,7 @@ void        cpu_proc_fork(struct proc *, struct proc *);
 int    amd64_pa_used(paddr_t);
 #define        cpu_idle_enter()        do { /* nothing */ } while (0)
 extern void (*cpu_idle_cycle_fcn)(void);
+#define        cpu_idle_cycle()        (*cpu_idle_cycle_fcn)()
 #define        cpu_idle_leave()        do { /* nothing */ } while (0)
 
 struct region_descriptor;