[patch 1/2] x86: apic_64 - make calibrate_APIC_clock to return error code

[patch 1/2] x86: apic_64 - make calibrate_APIC_clock to return error code

[Cyrill Gorcunov]

[-- Attachment #1: cvgapic-calibrate-64 --]
[-- Type: text/plain, Size: 1552 bytes --]

Make calibration_result to return error and check calibration_result
to be sufficient inside calibrate_APIC_clock.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

Index: linux-2.6.git/arch/x86/kernel/apic_64.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kernel/apic_64.c	2008-07-15 19:44:28.000000000 +0400
+++ linux-2.6.git/arch/x86/kernel/apic_64.c	2008-07-15 19:51:01.000000000 +0400
@@ -314,7 +314,7 @@ static void setup_APIC_timer(void)
 
 #define TICK_COUNT 100000000
 
-static void __init calibrate_APIC_clock(void)
+static int __init calibrate_APIC_clock(void)
 {
 	unsigned apic, apic_start;
 	unsigned long tsc, tsc_start;
@@ -368,6 +368,17 @@ static void __init calibrate_APIC_clock(
 		clockevent_delta2ns(0xF, &lapic_clockevent);
 
 	calibration_result = result / HZ;
+
+	/*
+	 * Do a sanity check on the APIC calibration result
+	 */
+	if (calibration_result < (1000000 / HZ)) {
+		printk(KERN_WARNING
+			"APIC frequency too slow, disabling apic timer\n");
+		return -1;
+	}
+
+	return 0;
 }
 
 /*
@@ -394,14 +405,7 @@ void __init setup_boot_APIC_clock(void)
 	}
 
 	printk(KERN_INFO "Using local APIC timer interrupts.\n");
-	calibrate_APIC_clock();
-
-	/*
-	 * Do a sanity check on the APIC calibration result
-	 */
-	if (calibration_result < (1000000 / HZ)) {
-		printk(KERN_WARNING
-		       "APIC frequency too slow, disabling apic timer\n");
+	if (calibrate_APIC_clock()) {
 		/* No broadcast on UP ! */
 		if (num_possible_cpus() > 1)
 			setup_APIC_timer();

-- 

[patch 2/2] x86: apic_32 - introduce calibrate_APIC_clock

[Cyrill Gorcunov]

[-- Attachment #1: cvgapic-calibrate-32 --]
[-- Type: text/plain, Size: 4060 bytes --]

Introduce calibrate_APIC_clock so it could help in further 32/64bit apic code merging.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

Index: linux-2.6.git/arch/x86/kernel/apic_32.c
===================================================================
--- linux-2.6.git.orig/arch/x86/kernel/apic_32.c	2008-07-15 20:04:05.000000000 +0400
+++ linux-2.6.git/arch/x86/kernel/apic_32.c	2008-07-15 20:13:12.000000000 +0400
@@ -372,12 +372,7 @@ static void __init lapic_cal_handler(str
 	}
 }
 
-/*
- * Setup the boot APIC
- *
- * Calibrate and verify the result.
- */
-void __init setup_boot_APIC_clock(void)
+static int __init calibrate_APIC_clock(void)
 {
 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
 	const long pm_100ms = PMTMR_TICKS_PER_SEC/10;
@@ -387,24 +382,6 @@ void __init setup_boot_APIC_clock(void)
 	long delta, deltapm;
 	int pm_referenced = 0;
 
-	/*
-	 * The local apic timer can be disabled via the kernel
-	 * commandline or from the CPU detection code. Register the lapic
-	 * timer as a dummy clock event source on SMP systems, so the
-	 * broadcast mechanism is used. On UP systems simply ignore it.
-	 */
-	if (local_apic_timer_disabled) {
-		/* No broadcast on UP ! */
-		if (num_possible_cpus() > 1) {
-			lapic_clockevent.mult = 1;
-			setup_APIC_timer();
-		}
-		return;
-	}
-
-	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
-		    "calibrating APIC timer ...\n");
-
 	local_irq_disable();
 
 	/* Replace the global interrupt handler */
@@ -489,8 +466,6 @@ void __init setup_boot_APIC_clock(void)
 		    calibration_result / (1000000 / HZ),
 		    calibration_result % (1000000 / HZ));
 
-	local_apic_timer_verify_ok = 1;
-
 	/*
 	 * Do a sanity check on the APIC calibration result
 	 */
@@ -498,12 +473,11 @@ void __init setup_boot_APIC_clock(void)
 		local_irq_enable();
 		printk(KERN_WARNING
 		       "APIC frequency too slow, disabling apic timer\n");
-		/* No broadcast on UP ! */
-		if (num_possible_cpus() > 1)
-			setup_APIC_timer();
-		return;
+		return -1;
 	}
 
+	local_apic_timer_verify_ok = 1;
+
 	/* We trust the pm timer based calibration */
 	if (!pm_referenced) {
 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
@@ -543,22 +517,55 @@ void __init setup_boot_APIC_clock(void)
 	if (!local_apic_timer_verify_ok) {
 		printk(KERN_WARNING
 		       "APIC timer disabled due to verification failure.\n");
+			return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Setup the boot APIC
+ *
+ * Calibrate and verify the result.
+ */
+void __init setup_boot_APIC_clock(void)
+{
+	/*
+	 * The local apic timer can be disabled via the kernel
+	 * commandline or from the CPU detection code. Register the lapic
+	 * timer as a dummy clock event source on SMP systems, so the
+	 * broadcast mechanism is used. On UP systems simply ignore it.
+	 */
+	if (local_apic_timer_disabled) {
 		/* No broadcast on UP ! */
-		if (num_possible_cpus() == 1)
-			return;
-	} else {
-		/*
-		 * If nmi_watchdog is set to IO_APIC, we need the
-		 * PIT/HPET going.  Otherwise register lapic as a dummy
-		 * device.
-		 */
-		if (nmi_watchdog != NMI_IO_APIC)
-			lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
-		else
-			printk(KERN_WARNING "APIC timer registered as dummy,"
-				" due to nmi_watchdog=%d!\n", nmi_watchdog);
+		if (num_possible_cpus() > 1) {
+			lapic_clockevent.mult = 1;
+			setup_APIC_timer();
+		}
+		return;
+	}
+
+	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
+		    "calibrating APIC timer ...\n");
+
+	if (calibrate_APIC_clock()) {
+		/* No broadcast on UP ! */
+		if (num_possible_cpus() > 1)
+			setup_APIC_timer();
+		return;
 	}
 
+	/*
+	 * If nmi_watchdog is set to IO_APIC, we need the
+	 * PIT/HPET going.  Otherwise register lapic as a dummy
+	 * device.
+	 */
+	if (nmi_watchdog != NMI_IO_APIC)
+		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+	else
+		printk(KERN_WARNING "APIC timer registered as dummy,"
+			" due to nmi_watchdog=%d!\n", nmi_watchdog);
+
 	/* Setup the lapic or request the broadcast */
 	setup_APIC_timer();
 }

--