x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period'

This variable is a period unit (number of clock cycles per jiffy),
not a frequency (which is number of cycles per second).

Give it a more appropriate name.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Daniel Drake <drake@endlessm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: len.brown@intel.com
Cc: linux@endlessm.com
Cc: rafael.j.wysocki@intel.com
Link: http://lkml.kernel.org/r/20190509055417.13152-2-drake@endlessm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/apic.h

@@ -52,7 +52,7 @@ extern unsigned int apic_verbosity;
 extern int local_apic_timer_c2_ok;
 
 extern int disable_apic;
-extern unsigned int lapic_timer_frequency;
+extern unsigned int lapic_timer_period;
 
 extern enum apic_intr_mode_id apic_intr_mode;
 enum apic_intr_mode_id {

arch/x86/kernel/apic/apic.c

@@ -194,7 +194,7 @@ static struct resource lapic_resource = {
 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
 };
 
-unsigned int lapic_timer_frequency = 0;
+unsigned int lapic_timer_period = 0;
 
 static void apic_pm_activate(void);
 
@@ -500,7 +500,7 @@ lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
 		return 0;
 
-	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
+	__setup_APIC_LVTT(lapic_timer_period, oneshot, 1);
 	return 0;
 }
 
@@ -804,11 +804,11 @@ calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
 
 static int __init lapic_init_clockevent(void)
 {
-	if (!lapic_timer_frequency)
+	if (!lapic_timer_period)
 		return -1;
 
 	/* Calculate the scaled math multiplication factor */
-	lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
+	lapic_clockevent.mult = div_sc(lapic_timer_period/APIC_DIVISOR,
 					TICK_NSEC, lapic_clockevent.shift);
 	lapic_clockevent.max_delta_ns =
 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
@@ -838,7 +838,7 @@ static int __init calibrate_APIC_clock(void)
 	 */
 	if (!lapic_init_clockevent()) {
 		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
-			    lapic_timer_frequency);
+			    lapic_timer_period);
 		/*
 		 * Direct calibration methods must have an always running
 		 * local APIC timer, no need for broadcast timer.
@@ -883,13 +883,13 @@ static int __init calibrate_APIC_clock(void)
 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
 					&delta, &deltatsc);
 
-	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
+	lapic_timer_period = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
 	lapic_init_clockevent();
 
 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
-		    lapic_timer_frequency);
+		    lapic_timer_period);
 
 	if (boot_cpu_has(X86_FEATURE_TSC)) {
 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
@@ -900,13 +900,13 @@ static int __init calibrate_APIC_clock(void)
 
 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
 		    "%u.%04u MHz.\n",
-		    lapic_timer_frequency / (1000000 / HZ),
-		    lapic_timer_frequency % (1000000 / HZ));
+		    lapic_timer_period / (1000000 / HZ),
+		    lapic_timer_period % (1000000 / HZ));
 
 	/*
 	 * Do a sanity check on the APIC calibration result
 	 */
-	if (lapic_timer_frequency < (1000000 / HZ)) {
+	if (lapic_timer_period < (1000000 / HZ)) {
 		local_irq_enable();
 		pr_warning("APIC frequency too slow, disabling apic timer\n");
 		return -1;

arch/x86/kernel/cpu/mshyperv.c

@@ -270,9 +270,9 @@ static void __init ms_hyperv_init_platform(void)
 
 		rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
 		hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
-		lapic_timer_frequency = hv_lapic_frequency;
+		lapic_timer_period = hv_lapic_frequency;
 		pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n",
-			lapic_timer_frequency);
+			lapic_timer_period);
 	}
 
 	register_nmi_handler(NMI_UNKNOWN, hv_nmi_unknown, NMI_FLAG_FIRST,

arch/x86/kernel/cpu/vmware.c

@@ -157,7 +157,7 @@ static void __init vmware_platform_setup(void)
 
 #ifdef CONFIG_X86_LOCAL_APIC
 		/* Skip lapic calibration since we know the bus frequency. */
-		lapic_timer_frequency = ecx / HZ;
+		lapic_timer_period = ecx / HZ;
 		pr_info("Host bus clock speed read from hypervisor : %u Hz\n",
 			ecx);
 #endif

arch/x86/kernel/jailhouse.c

@@ -45,7 +45,7 @@ static void jailhouse_get_wallclock(struct timespec64 *now)
 
 static void __init jailhouse_timer_init(void)
 {
-	lapic_timer_frequency = setup_data.apic_khz * (1000 / HZ);
+	lapic_timer_period = setup_data.apic_khz * (1000 / HZ);
 }
 
 static unsigned long jailhouse_get_tsc(void)

arch/x86/kernel/tsc_msr.c

@@ -71,7 +71,7 @@ static const struct x86_cpu_id tsc_msr_cpu_ids[] = {
 /*
  * MSR-based CPU/TSC frequency discovery for certain CPUs.
  *
- * Set global "lapic_timer_frequency" to bus_clock_cycles/jiffy
+ * Set global "lapic_timer_period" to bus_clock_cycles/jiffy
  * Return processor base frequency in KHz, or 0 on failure.
  */
 unsigned long cpu_khz_from_msr(void)
@@ -104,7 +104,7 @@ unsigned long cpu_khz_from_msr(void)
 	res = freq * ratio;
 
 #ifdef CONFIG_X86_LOCAL_APIC
-	lapic_timer_frequency = (freq * 1000) / HZ;
+	lapic_timer_period = (freq * 1000) / HZ;
 #endif
 
 	/*