X-Git-Url: http://git.agner.ch/gitweb/?a=blobdiff_plain;f=arch%2Fx86_64%2Fkernel%2Fsmp.c;h=bd1d123947ce9662f363f5e6d551d468361db49e;hb=e3ebadd95cb621e2c7436f3d3646447ac9d5c16d;hp=06af6ca601295e8253b95b999435710fdc8672e2;hpb=8ce7a9c159c8c4eb480f0a65c6af753dbf9a1a70;p=linux-drm-fsl-dcu.git

diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
index 06af6ca60129..bd1d123947ce 100644
--- a/arch/x86_64/kernel/smp.c
+++ b/arch/x86_64/kernel/smp.c
@@ -376,16 +376,20 @@ int smp_call_function_single (int cpu, void (*func) (void *info), void *info,
 	/* prevent preemption and reschedule on another processor */
 	int me = get_cpu();
 	if (cpu == me) {
-		WARN_ON(1);
 		put_cpu();
-		return -EBUSY;
+		return 0;
 	}
+
+	/* Can deadlock when called with interrupts disabled */
+	WARN_ON(irqs_disabled());
+
 	spin_lock_bh(&call_lock);
 	__smp_call_function_single(cpu, func, info, nonatomic, wait);
 	spin_unlock_bh(&call_lock);
 	put_cpu();
 	return 0;
 }
+EXPORT_SYMBOL(smp_call_function_single);
 
 /*
  * this function sends a 'generic call function' IPI to all other CPUs
@@ -448,42 +452,34 @@ int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
 }
 EXPORT_SYMBOL(smp_call_function);
 
-void smp_stop_cpu(void)
+static void stop_this_cpu(void *dummy)
 {
-	unsigned long flags;
+	local_irq_disable();
 	/*
 	 * Remove this CPU:
 	 */
 	cpu_clear(smp_processor_id(), cpu_online_map);
-	local_irq_save(flags);
 	disable_local_APIC();
-	local_irq_restore(flags);
-}
-
-static void smp_really_stop_cpu(void *dummy)
-{
-	smp_stop_cpu(); 
 	for (;;) 
 		halt();
 } 
 
 void smp_send_stop(void)
 {
-	int nolock = 0;
+	int nolock;
+	unsigned long flags;
+
 	if (reboot_force)
 		return;
+
 	/* Don't deadlock on the call lock in panic */
-	if (!spin_trylock(&call_lock)) {
-		/* ignore locking because we have panicked anyways */
-		nolock = 1;
-	}
-	__smp_call_function(smp_really_stop_cpu, NULL, 0, 0);
+	nolock = !spin_trylock(&call_lock);
+	local_irq_save(flags);
+	__smp_call_function(stop_this_cpu, NULL, 0, 0);
 	if (!nolock)
 		spin_unlock(&call_lock);
-
-	local_irq_disable();
 	disable_local_APIC();
-	local_irq_enable();
+	local_irq_restore(flags);
 }
 
 /*
@@ -522,26 +518,3 @@ asmlinkage void smp_call_function_interrupt(void)
 	}
 }
 
-int safe_smp_processor_id(void)
-{
-	unsigned apicid, i;
-
-	if (disable_apic)
-		return 0;
-
-	apicid = hard_smp_processor_id();
-	if (apicid < NR_CPUS && x86_cpu_to_apicid[apicid] == apicid)
-		return apicid;
-
-	for (i = 0; i < NR_CPUS; ++i) {
-		if (x86_cpu_to_apicid[i] == apicid)
-			return i;
-	}
-
-	/* No entries in x86_cpu_to_apicid?  Either no MPS|ACPI,
-	 * or called too early.  Either way, we must be CPU 0. */
-      	if (x86_cpu_to_apicid[0] == BAD_APICID)
-		return 0;
-
-	return 0; /* Should not happen */
-}