Linux-libre 4.3.2-gnu

1 files changed, 18 insertions, 21 deletions

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index b1f3ed9c7..892ee2e5e 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -97,8 +97,6 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);
 DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
 EXPORT_PER_CPU_SYMBOL(cpu_info);
 
-atomic_t init_deasserted;
-
 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
 {
 	unsigned long flags;
@@ -146,16 +144,11 @@ static void smp_callin(void)
 
 	/*
 	 * If waken up by an INIT in an 82489DX configuration
-	 * we may get here before an INIT-deassert IPI reaches
-	 * our local APIC.  We have to wait for the IPI or we'll
-	 * lock up on an APIC access.
-	 *
-	 * Since CPU0 is not wakened up by INIT, it doesn't wait for the IPI.
+	 * cpu_callout_mask guarantees we don't get here before
+	 * an INIT_deassert IPI reaches our local APIC, so it is
+	 * now safe to touch our local APIC.
 	 */
 	cpuid = smp_processor_id();
-	if (apic->wait_for_init_deassert && cpuid)
-		while (!atomic_read(&init_deasserted))
-			cpu_relax();
 
 	/*
 	 * (This works even if the APIC is not enabled.)
@@ -516,7 +509,7 @@ void __inquire_remote_apic(int apicid)
  */
 #define UDELAY_10MS_DEFAULT 10000
 
-static unsigned int init_udelay = UDELAY_10MS_DEFAULT;
+static unsigned int init_udelay = INT_MAX;
 
 static int __init cpu_init_udelay(char *str)
 {
@@ -529,13 +522,16 @@ early_param("cpu_init_udelay", cpu_init_udelay);
 static void __init smp_quirk_init_udelay(void)
 {
 	/* if cmdline changed it from default, leave it alone */
-	if (init_udelay != UDELAY_10MS_DEFAULT)
+	if (init_udelay != INT_MAX)
 		return;
 
 	/* if modern processor, use no delay */
 	if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) ||
 	    ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF)))
 		init_udelay = 0;
+
+	/* else, use legacy delay */
+	init_udelay = UDELAY_10MS_DEFAULT;
 }
 
 /*
@@ -620,7 +616,6 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
 	send_status = safe_apic_wait_icr_idle();
 
 	mb();
-	atomic_set(&init_deasserted, 1);
 
 	/*
 	 * Should we send STARTUP IPIs ?
@@ -665,7 +660,10 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
 		/*
 		 * Give the other CPU some time to accept the IPI.
 		 */
-		udelay(300);
+		if (init_udelay == 0)
+			udelay(10);
+		else
+			udelay(300);
 
 		pr_debug("Startup point 1\n");
 
@@ -675,7 +673,10 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
 		/*
 		 * Give the other CPU some time to accept the IPI.
 		 */
-		udelay(200);
+		if (init_udelay == 0)
+			udelay(10);
+		else
+			udelay(200);
 
 		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP.  */
 			apic_write(APIC_ESR, 0);
@@ -859,8 +860,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
 	 * the targeted processor.
 	 */
 
-	atomic_set(&init_deasserted, 0);
-
 	if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
 
 		pr_debug("Setting warm reset code and vector.\n");
@@ -898,7 +897,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
 
 	if (!boot_error) {
 		/*
-		 * Wait 10s total for a response from AP
+		 * Wait 10s total for first sign of life from AP
 		 */
 		boot_error = -1;
 		timeout = jiffies + 10*HZ;
@@ -911,7 +910,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
 				boot_error = 0;
 				break;
 			}
-			udelay(100);
 			schedule();
 		}
 	}
@@ -927,7 +925,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
 			 * for the MTRR work(triggered by the AP coming online)
 			 * to be completed in the stop machine context.
 			 */
-			udelay(100);
 			schedule();
 		}
 	}
@@ -1358,7 +1355,7 @@ static void remove_siblinginfo(int cpu)
 	cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
 }
 
-static void __ref remove_cpu_from_maps(int cpu)
+static void remove_cpu_from_maps(int cpu)
 {
 	set_cpu_online(cpu, false);
 	cpumask_clear_cpu(cpu, cpu_callout_mask);