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

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 130e81e..fc505a8 100644 (file)
--- a/arch/x86/include/asm/apic.h
+++ b/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 {

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index ab6af77..93de786 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/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;

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 3fa238a..faae611 100644 (file)
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/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,

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 0eda91f..3c64847 100644 (file)
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/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

diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index 1b2ee55..ba95bc7 100644 (file)
--- a/arch/x86/kernel/jailhouse.c
+++ b/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)

diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c
index 3d0e9ae..067858f 100644 (file)
--- a/arch/x86/kernel/tsc_msr.c
+++ b/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
 
        /*