Messages in this thread Patch in this message | | | Subject | [PATCH] x86,apic: V2 Add apic calibration hook. | From | Alok Kataria <> | Date | Mon, 20 Sep 2010 14:17:05 -0700 |
| |
Hi,
I am reposting the version 2 of the apic calibration hook from the original thread [1]. Please note that I never heard back anything on this version, any review comments are much appreciated.
If all looks good, please consider for inclusion. Patch applies on the tip tree.
Thanks, Alok
[1] http://lkml.org/lkml/2010/8/27/421 --
Add apic calibration hook.
From: Alok N Kataria <akataria@vmware.com>
Add a new function ptr calibrate_apic to x86_init_ops structure. On native this does the usual apic calibration. On VMware's platform we override it with a routine which gets that information from the hypervisor.
Signed-off-by: Alok N Kataria <akataria@vmware.com> Cc: H. Peter Anvin <hpa@zytor.com> ---
arch/x86/include/asm/apic.h | 6 +++ arch/x86/include/asm/x86_init.h | 2 + arch/x86/kernel/apic/apic.c | 88 ++++++++++++++++++++------------------- arch/x86/kernel/cpu/vmware.c | 30 ++++++++++++- arch/x86/kernel/x86_init.c | 1 5 files changed, 82 insertions(+), 45 deletions(-)
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 1fa03e0..5012ee5 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -17,6 +17,10 @@ #define ARCH_APICTIMER_STOPS_ON_C3 1 +/* Clock divisor */ +#define APIC_DIVISOR 16 +#define LAPIC_CAL_LOOPS (HZ/10) + /* * Debugging macros */ @@ -238,6 +242,8 @@ extern void setup_boot_APIC_clock(void); extern void setup_secondary_APIC_clock(void); extern int APIC_init_uniprocessor(void); extern void enable_NMI_through_LVT0(void); +extern int native_calibrate_apic(void); +extern int initialize_lapic(long delta, unsigned int calibration_result); /* * On 32bit this is mach-xxx local diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index baa579c..58f982b 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -83,11 +83,13 @@ struct x86_init_paging { * boot cpu * @tsc_pre_init: platform function called before TSC init * @timer_init: initialize the platform timer (default PIT/HPET) + * @calibrate_apic: calibrate APIC bus freq (ticks per HZ) */ struct x86_init_timers { void (*setup_percpu_clockev)(void); void (*tsc_pre_init)(void); void (*timer_init)(void); + int (*calibrate_apic)(void); }; /** diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index e3b534c..ca5d084 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -176,7 +176,7 @@ static struct resource lapic_resource = { .flags = IORESOURCE_MEM | IORESOURCE_BUSY, }; -static unsigned int calibration_result; +static unsigned int apic_calibration_res; static int lapic_next_event(unsigned long delta, struct clock_event_device *evt); @@ -326,13 +326,6 @@ int lapic_get_maxlvt(void) } /* - * Local APIC timer - */ - -/* Clock divisor */ -#define APIC_DIVISOR 16 - -/* * This function sets up the local APIC timer, with a timeout of * 'clocks' APIC bus clock. During calibration we actually call * this function twice on the boot CPU, once with a bogus timeout @@ -431,7 +424,7 @@ static void lapic_timer_setup(enum clock_event_mode mode, switch (mode) { case CLOCK_EVT_MODE_PERIODIC: case CLOCK_EVT_MODE_ONESHOT: - __setup_APIC_LVTT(calibration_result, + __setup_APIC_LVTT(apic_calibration_res, mode != CLOCK_EVT_MODE_PERIODIC, 1); break; case CLOCK_EVT_MODE_UNUSED: @@ -500,8 +493,6 @@ static void __cpuinit setup_APIC_timer(void) * back to normal later in the boot process). */ -#define LAPIC_CAL_LOOPS (HZ/10) - static __initdata int lapic_cal_loops = -1; static __initdata long lapic_cal_t1, lapic_cal_t2; static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2; @@ -590,13 +581,50 @@ calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc) return 0; } -static int __init calibrate_APIC_clock(void) +int __init initialize_lapic(long delta, unsigned int calibration_result) +{ + struct clock_event_device *levt = &__get_cpu_var(lapic_events); + + /* Calculate the scaled math multiplication factor */ + lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS, + lapic_clockevent.shift); + lapic_clockevent.max_delta_ns = + clockevent_delta2ns(0x7FFFFF, &lapic_clockevent); + lapic_clockevent.min_delta_ns = + clockevent_delta2ns(0xF, &lapic_clockevent); + + apic_calibration_res = calibration_result; + + 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", + calibration_result); + + apic_printk(APIC_VERBOSE, "..... host bus clock speed is " + "%u.%04u MHz.\n", + calibration_result / (1000000 / HZ), + calibration_result % (1000000 / HZ)); + + /* + * Do a sanity check on the APIC calibration result + */ + if (calibration_result < (1000000 / HZ)) { + pr_warning("APIC frequency too slow, disabling apic timer\n"); + return -1; + } + + levt->features &= ~CLOCK_EVT_FEAT_DUMMY; + return 0; +} + +int __init native_calibrate_apic(void) { struct clock_event_device *levt = &__get_cpu_var(lapic_events); void (*real_handler)(struct clock_event_device *dev); unsigned long deltaj; long delta, deltatsc; int pm_referenced = 0; + unsigned int calibration_result; local_irq_disable(); @@ -631,20 +659,12 @@ static int __init calibrate_APIC_clock(void) pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1, &delta, &deltatsc); - /* Calculate the scaled math multiplication factor */ - lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS, - lapic_clockevent.shift); - lapic_clockevent.max_delta_ns = - clockevent_delta2ns(0x7FFFFF, &lapic_clockevent); - lapic_clockevent.min_delta_ns = - clockevent_delta2ns(0xF, &lapic_clockevent); - calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS; - 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", - calibration_result); + if (initialize_lapic(delta, calibration_result)) { + local_irq_enable(); + return -1; + } if (cpu_has_tsc) { apic_printk(APIC_VERBOSE, "..... CPU clock speed is " @@ -653,22 +673,6 @@ static int __init calibrate_APIC_clock(void) (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ)); } - apic_printk(APIC_VERBOSE, "..... host bus clock speed is " - "%u.%04u MHz.\n", - calibration_result / (1000000 / HZ), - calibration_result % (1000000 / HZ)); - - /* - * Do a sanity check on the APIC calibration result - */ - if (calibration_result < (1000000 / HZ)) { - local_irq_enable(); - pr_warning("APIC frequency too slow, disabling apic timer\n"); - return -1; - } - - levt->features &= ~CLOCK_EVT_FEAT_DUMMY; - /* * PM timer calibration failed or not turned on * so lets try APIC timer based calibration @@ -706,7 +710,7 @@ static int __init calibrate_APIC_clock(void) if (levt->features & CLOCK_EVT_FEAT_DUMMY) { pr_warning("APIC timer disabled due to verification failure\n"); - return -1; + return -1; } return 0; @@ -738,7 +742,7 @@ void __init setup_boot_APIC_clock(void) apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n" "calibrating APIC timer ...\n"); - if (calibrate_APIC_clock()) { + if (x86_init.timers.calibrate_apic()) { /* No broadcast on UP ! */ if (num_possible_cpus() > 1) setup_APIC_timer(); diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index 227b044..e8b760e 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -26,6 +26,7 @@ #include <asm/div64.h> #include <asm/x86_init.h> #include <asm/hypervisor.h> +#include <asm/apic.h> #define CPUID_VMWARE_INFO_LEAF 0x40000000 #define VMWARE_HYPERVISOR_MAGIC 0x564D5868 @@ -72,17 +73,40 @@ static unsigned long vmware_get_tsc_khz(void) return tsc_hz; } +static int __init vmware_calibrate_apic(void) +{ + unsigned int calibration_result; + uint32_t eax, ebx, ecx, edx; + int err; + long delta; + unsigned long flags; + + VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); + BUG_ON(!ecx); + calibration_result = ecx / HZ; + + printk(KERN_INFO "APIC bus freq read from hypervisor\n"); + + delta = (calibration_result * LAPIC_CAL_LOOPS) / APIC_DIVISOR; + local_irq_save(flags); + err = initialize_lapic(delta, calibration_result); + local_irq_restore(flags); + + return err; +} + static void __init vmware_platform_setup(void) { uint32_t eax, ebx, ecx, edx; VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); - if (ebx != UINT_MAX) + if (ebx != UINT_MAX) { x86_platform.calibrate_tsc = vmware_get_tsc_khz; - else + x86_init.timers.calibrate_apic = vmware_calibrate_apic; + } else printk(KERN_WARNING - "Failed to get TSC freq from the hypervisor\n"); + "Failed to setup VMware hypervisor platform\n"); } /* diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index cd6da6b..f162e14 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -68,6 +68,7 @@ struct x86_init_ops x86_init __initdata = { .setup_percpu_clockev = setup_boot_APIC_clock, .tsc_pre_init = x86_init_noop, .timer_init = hpet_time_init, + .calibrate_apic = native_calibrate_apic }, .iommu = {
| |