Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
	arch/x86/include/asm/percpu.h
	arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 7 insertions, 32 deletions

diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 1bb79526c217..2908e063d7d8 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -131,7 +131,7 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
 }
 
 /*
- * Disable virtualization, APIC etc. and park the CPU in a HLT loop
+ * this function calls the 'stop' function on all other CPUs in the system.
  */
 DEFINE_IDTENTRY_SYSVEC(sysvec_reboot)
 {
@@ -174,17 +174,13 @@ static void native_stop_other_cpus(int wait)
 	 * 2) Wait for all other CPUs to report that they reached the
 	 *    HLT loop in stop_this_cpu()
 	 *
-	 * 3) If the system uses INIT/STARTUP for CPU bringup, then
-	 *    send all present CPUs an INIT vector, which brings them
-	 *    completely out of the way.
+	 * 3) If #2 timed out send an NMI to the CPUs which did not
+	 *    yet report
 	 *
-	 * 4) If #3 is not possible and #2 timed out send an NMI to the
-	 *    CPUs which did not yet report
-	 *
-	 * 5) Wait for all other CPUs to report that they reached the
+	 * 4) Wait for all other CPUs to report that they reached the
 	 *    HLT loop in stop_this_cpu()
 	 *
-	 * #4 can obviously race against a CPU reaching the HLT loop late.
+	 * #3 can obviously race against a CPU reaching the HLT loop late.
 	 * That CPU will have reported already and the "have all CPUs
 	 * reached HLT" condition will be true despite the fact that the
 	 * other CPU is still handling the NMI. Again, there is no
@@ -200,7 +196,7 @@ static void native_stop_other_cpus(int wait)
 		/*
 		 * Don't wait longer than a second for IPI completion. The
 		 * wait request is not checked here because that would
-		 * prevent an NMI/INIT shutdown in case that not all
+		 * prevent an NMI shutdown attempt in case that not all
 		 * CPUs reach shutdown state.
 		 */
 		timeout = USEC_PER_SEC;
@@ -208,27 +204,7 @@ static void native_stop_other_cpus(int wait)
 			udelay(1);
 	}
 
-	/*
-	 * Park all other CPUs in INIT including "offline" CPUs, if
-	 * possible. That's a safe place where they can't resume execution
-	 * of HLT and then execute the HLT loop from overwritten text or
-	 * page tables.
-	 *
-	 * The only downside is a broadcast MCE, but up to the point where
-	 * the kexec() kernel brought all APs online again an MCE will just
-	 * make HLT resume and handle the MCE. The machine crashes and burns
-	 * due to overwritten text, page tables and data. So there is a
-	 * choice between fire and frying pan. The result is pretty much
-	 * the same. Chose frying pan until x86 provides a sane mechanism
-	 * to park a CPU.
-	 */
-	if (smp_park_other_cpus_in_init())
-		goto done;
-
-	/*
-	 * If park with INIT was not possible and the REBOOT_VECTOR didn't
-	 * take all secondary CPUs offline, try with the NMI.
-	 */
+	/* if the REBOOT_VECTOR didn't work, try with the NMI */
 	if (!cpumask_empty(&cpus_stop_mask)) {
 		/*
 		 * If NMI IPI is enabled, try to register the stop handler
@@ -253,7 +229,6 @@ static void native_stop_other_cpus(int wait)
 			udelay(1);
 	}
 
-done:
 	local_irq_save(flags);
 	disable_local_APIC();
 	mcheck_cpu_clear(this_cpu_ptr(&cpu_info));