Revert "Revert "MFC r327818:""

This reverts commit c1ee180537f04875eccd8e9b3d630b73ad654b14.

3 files changed, 20 insertions, 22 deletions

diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index a0d34f0..3ed29e0 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1523,6 +1523,22 @@ amd64_kdb_init(void)
 #endif
 }
 
+/* Set up the fast syscall stuff */
+void
+amd64_conf_fast_syscall(void)
+{
+	uint64_t msr;
+
+	msr = rdmsr(MSR_EFER) | EFER_SCE;
+	wrmsr(MSR_EFER, msr);
+	wrmsr(MSR_LSTAR, (u_int64_t)IDTVEC(fast_syscall));
+	wrmsr(MSR_CSTAR, (u_int64_t)IDTVEC(fast_syscall32));
+	msr = ((u_int64_t)GSEL(GCODE_SEL, SEL_KPL) << 32) |
+	    ((u_int64_t)GSEL(GUCODE32_SEL, SEL_UPL) << 48);
+	wrmsr(MSR_STAR, msr);
+	wrmsr(MSR_SF_MASK, PSL_NT | PSL_T | PSL_I | PSL_C | PSL_D);
+}
+
 u_int64_t
 hammer_time(u_int64_t modulep, u_int64_t physfree)
 {
@@ -1531,7 +1547,6 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
 	struct pcpu *pc;
 	struct nmi_pcpu *np;
 	struct xstate_hdr *xhdr;
-	u_int64_t msr;
 	char *env;
 	size_t kstack0_sz;
 	int late_console;
@@ -1672,15 +1687,7 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
 	gsel_tss = GSEL(GPROC0_SEL, SEL_KPL);
 	ltr(gsel_tss);
 
-	/* Set up the fast syscall stuff */
-	msr = rdmsr(MSR_EFER) | EFER_SCE;
-	wrmsr(MSR_EFER, msr);
-	wrmsr(MSR_LSTAR, (u_int64_t)IDTVEC(fast_syscall));
-	wrmsr(MSR_CSTAR, (u_int64_t)IDTVEC(fast_syscall32));
-	msr = ((u_int64_t)GSEL(GCODE_SEL, SEL_KPL) << 32) |
-	      ((u_int64_t)GSEL(GUCODE32_SEL, SEL_UPL) << 48);
-	wrmsr(MSR_STAR, msr);
-	wrmsr(MSR_SF_MASK, PSL_NT|PSL_T|PSL_I|PSL_C|PSL_D);
+	amd64_conf_fast_syscall();
 
 	/*
 	 * Temporary forge some valid pointer to PCB, for exception
diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index ce07e0f..70b2e6d 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -87,8 +87,6 @@ extern	struct pcpu __pcpu[];
 char *doublefault_stack;
 char *nmi_stack;
 
-extern inthand_t IDTVEC(fast_syscall), IDTVEC(fast_syscall32);
-
 /*
  * Local data and functions.
  */
@@ -188,7 +186,7 @@ init_secondary(void)
 {
 	struct pcpu *pc;
 	struct nmi_pcpu *np;
-	u_int64_t msr, cr0;
+	u_int64_t cr0;
 	int cpu, gsel_tss, x;
 	struct region_descriptor ap_gdt;
 
@@ -263,15 +261,7 @@ init_secondary(void)
 	cr0 &= ~(CR0_CD | CR0_NW | CR0_EM);
 	load_cr0(cr0);
 
-	/* Set up the fast syscall stuff */
-	msr = rdmsr(MSR_EFER) | EFER_SCE;
-	wrmsr(MSR_EFER, msr);
-	wrmsr(MSR_LSTAR, (u_int64_t)IDTVEC(fast_syscall));
-	wrmsr(MSR_CSTAR, (u_int64_t)IDTVEC(fast_syscall32));
-	msr = ((u_int64_t)GSEL(GCODE_SEL, SEL_KPL) << 32) |
-	      ((u_int64_t)GSEL(GUCODE32_SEL, SEL_UPL) << 48);
-	wrmsr(MSR_STAR, msr);
-	wrmsr(MSR_SF_MASK, PSL_NT|PSL_T|PSL_I|PSL_C|PSL_D);
+	amd64_conf_fast_syscall();
 
 	/* signal our startup to the BSP. */
 	mp_naps++;
diff --git a/sys/amd64/include/md_var.h b/sys/amd64/include/md_var.h
index e4c50eb..706ffc6 100644
--- a/sys/amd64/include/md_var.h
+++ b/sys/amd64/include/md_var.h
@@ -38,6 +38,7 @@ extern  uint64_t *vm_page_dump;
 
 struct	savefpu;
 
+void	amd64_conf_fast_syscall(void);
 void	amd64_db_resume_dbreg(void);
 void	amd64_syscall(struct thread *td, int traced);
 void	doreti_iret(void) __asm(__STRING(doreti_iret));