From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753416Ab0HRT1n (ORCPT ); Wed, 18 Aug 2010 15:27:43 -0400 Received: from smtp-outbound-1.vmware.com ([65.115.85.69]:58316 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752911Ab0HRT1l (ORCPT ); Wed, 18 Aug 2010 15:27:41 -0400 Subject: Re: [PATCH] x86, apic: Add apic calibration hook. From: Alok Kataria Reply-To: akataria@vmware.com To: "H. Peter Anvin" Cc: the arch/x86 maintainers , LKML In-Reply-To: <1282153304.15158.39.camel@ank32.eng.vmware.com> References: <1282153304.15158.39.camel@ank32.eng.vmware.com> Content-Type: text/plain Organization: VMware INC. Date: Wed, 18 Aug 2010 12:27:40 -0700 Message-Id: <1282159660.15158.56.camel@ank32.eng.vmware.com> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 (2.12.3-8.el5_2.3) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Here is the patch which adds this hook in the x86_init_ops.timers structure. --- 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 Cc: H. Peter Anvin Index: linux-x86-tree.git/arch/x86/include/asm/apic.h =================================================================== --- linux-x86-tree.git.orig/arch/x86/include/asm/apic.h 2010-08-17 15:29:21.000000000 -0700 +++ linux-x86-tree.git/arch/x86/include/asm/apic.h 2010-08-17 15:32:11.000000000 -0700 @@ -238,6 +238,7 @@ 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 unsigned int native_calibrate_apic(void); /* * On 32bit this is mach-xxx local Index: linux-x86-tree.git/arch/x86/include/asm/x86_init.h =================================================================== --- linux-x86-tree.git.orig/arch/x86/include/asm/x86_init.h 2010-08-17 15:29:21.000000000 -0700 +++ linux-x86-tree.git/arch/x86/include/asm/x86_init.h 2010-08-18 12:01:35.000000000 -0700 @@ -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 */ struct x86_init_timers { void (*setup_percpu_clockev)(void); void (*tsc_pre_init)(void); void (*timer_init)(void); + unsigned int (*calibrate_apic)(void); }; /** Index: linux-x86-tree.git/arch/x86/kernel/apic/apic.c =================================================================== --- linux-x86-tree.git.orig/arch/x86/kernel/apic/apic.c 2010-08-17 15:29:21.000000000 -0700 +++ linux-x86-tree.git/arch/x86/kernel/apic/apic.c 2010-08-18 12:05:33.000000000 -0700 @@ -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); @@ -431,7 +431,7 @@ static void lapic_timer_setup(enum clock 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: @@ -590,13 +590,46 @@ calibrate_by_pmtimer(long deltapm, long return 0; } +static void __init initialize_lapic_clkevt(long delta) +{ + /* 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); +} + static int __init calibrate_APIC_clock(void) { + apic_calibration_res = x86_init.timers.calibrate_apic(); + if (apic_calibration_res) { + struct clock_event_device *levt = &__get_cpu_var(lapic_events); + long delta; + + if (lapic_clockevent.mult) + return 0; + + delta = (apic_calibration_res * LAPIC_CAL_LOOPS) / APIC_DIVISOR; + initialize_lapic_clkevt(delta); + levt->features &= ~CLOCK_EVT_FEAT_DUMMY; + return 0; + } else { + pr_warning("Unable to calibrate APIC frequency, " + "disabling apic timer\n"); + return -1; + } +} + +unsigned 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(); @@ -631,14 +664,7 @@ static int __init calibrate_APIC_clock(v 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); - + initialize_lapic_clkevt(delta); calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS; apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta); @@ -664,7 +690,7 @@ static int __init calibrate_APIC_clock(v if (calibration_result < (1000000 / HZ)) { local_irq_enable(); pr_warning("APIC frequency too slow, disabling apic timer\n"); - return -1; + return 0; } levt->features &= ~CLOCK_EVT_FEAT_DUMMY; @@ -706,10 +732,10 @@ static int __init calibrate_APIC_clock(v if (levt->features & CLOCK_EVT_FEAT_DUMMY) { pr_warning("APIC timer disabled due to verification failure\n"); - return -1; + return 0; } - return 0; + return calibration_result; } /* Index: linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c =================================================================== --- linux-x86-tree.git.orig/arch/x86/kernel/cpu/vmware.c 2010-08-17 15:29:21.000000000 -0700 +++ linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c 2010-08-18 12:24:57.000000000 -0700 @@ -72,17 +72,33 @@ static unsigned long vmware_get_tsc_khz( return tsc_hz; } +static unsigned int __init vmware_calibrate_apic(void) +{ + unsigned int calibration_result; + uint32_t eax, ebx, ecx, edx; + + VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); + BUG_ON(!ecx); + calibration_result = ecx / HZ; + + printk(KERN_INFO "APIC bus freq read from hypervisor : %u.%03u MHz\n", + calibration_result / (1000000 / HZ), + calibration_result % (1000000 / HZ)); + return calibration_result; +} + 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"); } /* Index: linux-x86-tree.git/arch/x86/kernel/x86_init.c =================================================================== --- linux-x86-tree.git.orig/arch/x86/kernel/x86_init.c 2010-08-17 15:29:21.000000000 -0700 +++ linux-x86-tree.git/arch/x86/kernel/x86_init.c 2010-08-18 12:00:09.000000000 -0700 @@ -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 = { @@ -95,7 +96,7 @@ struct x86_platform_ops x86_platform = { .iommu_shutdown = iommu_shutdown_noop, .is_untracked_pat_range = is_ISA_range, .nmi_init = default_nmi_init, - .i8042_detect = default_i8042_detect + .i8042_detect = default_i8042_detect, }; EXPORT_SYMBOL_GPL(x86_platform); On Wed, 2010-08-18 at 10:41 -0700, Alok Kataria wrote: > Add a new function pointer calibrate_apic to x86_platform_ops. 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 > Cc: H. Peter Anvin > > Index: linux-x86-tree.git/arch/x86/include/asm/apic.h > =================================================================== > --- linux-x86-tree.git.orig/arch/x86/include/asm/apic.h 2010-08-17 15:29:21.000000000 -0700 > +++ linux-x86-tree.git/arch/x86/include/asm/apic.h 2010-08-17 15:32:11.000000000 -0700 > @@ -238,6 +238,7 @@ 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 unsigned int native_calibrate_apic(void); > > /* > * On 32bit this is mach-xxx local > Index: linux-x86-tree.git/arch/x86/include/asm/x86_init.h > =================================================================== > --- linux-x86-tree.git.orig/arch/x86/include/asm/x86_init.h 2010-08-17 15:29:21.000000000 -0700 > +++ linux-x86-tree.git/arch/x86/include/asm/x86_init.h 2010-08-18 10:20:21.000000000 -0700 > @@ -143,6 +143,7 @@ struct x86_cpuinit_ops { > * @is_untracked_pat_range exclude from PAT logic > * @nmi_init enable NMI on cpus > * @i8042_detect pre-detect if i8042 controller exists > + * @calibrate_apic: calibrate APIC bus freq > */ > struct x86_platform_ops { > unsigned long (*calibrate_tsc)(void); > @@ -152,6 +153,7 @@ struct x86_platform_ops { > bool (*is_untracked_pat_range)(u64 start, u64 end); > void (*nmi_init)(void); > int (*i8042_detect)(void); > + unsigned int (*calibrate_apic)(void); > }; > > extern struct x86_init_ops x86_init; > Index: linux-x86-tree.git/arch/x86/kernel/apic/apic.c > =================================================================== > --- linux-x86-tree.git.orig/arch/x86/kernel/apic/apic.c 2010-08-17 15:29:21.000000000 -0700 > +++ linux-x86-tree.git/arch/x86/kernel/apic/apic.c 2010-08-18 10:20:55.000000000 -0700 > @@ -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); > @@ -431,7 +431,7 @@ static void lapic_timer_setup(enum clock > 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: > @@ -590,13 +590,46 @@ calibrate_by_pmtimer(long deltapm, long > return 0; > } > > +static void __init initialize_lapic_clkevt(long delta) > +{ > + /* 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); > +} > + > static int __init calibrate_APIC_clock(void) > { > + apic_calibration_res = x86_platform.calibrate_apic(); > + if (apic_calibration_res) { > + struct clock_event_device *levt = &__get_cpu_var(lapic_events); > + long delta; > + > + if (lapic_clockevent.mult) > + return 0; > + > + delta = (apic_calibration_res * LAPIC_CAL_LOOPS) / APIC_DIVISOR; > + initialize_lapic_clkevt(delta); > + levt->features &= ~CLOCK_EVT_FEAT_DUMMY; > + return 0; > + } else { > + pr_warning("Unable to calibrate APIC frequency, " > + "disabling apic timer\n"); > + return -1; > + } > +} > + > +unsigned 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(); > > @@ -631,14 +664,7 @@ static int __init calibrate_APIC_clock(v > 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); > - > + initialize_lapic_clkevt(delta); > calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS; > > apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta); > @@ -664,7 +690,7 @@ static int __init calibrate_APIC_clock(v > if (calibration_result < (1000000 / HZ)) { > local_irq_enable(); > pr_warning("APIC frequency too slow, disabling apic timer\n"); > - return -1; > + return 0; > } > > levt->features &= ~CLOCK_EVT_FEAT_DUMMY; > @@ -706,10 +732,10 @@ static int __init calibrate_APIC_clock(v > > if (levt->features & CLOCK_EVT_FEAT_DUMMY) { > pr_warning("APIC timer disabled due to verification failure\n"); > - return -1; > + return 0; > } > > - return 0; > + return calibration_result; > } > > /* > Index: linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c > =================================================================== > --- linux-x86-tree.git.orig/arch/x86/kernel/cpu/vmware.c 2010-08-17 15:29:21.000000000 -0700 > +++ linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c 2010-08-18 10:20:21.000000000 -0700 > @@ -72,17 +72,33 @@ static unsigned long vmware_get_tsc_khz( > return tsc_hz; > } > > +static unsigned int vmware_calibrate_apic(void) > +{ > + unsigned int calibration_result; > + uint32_t eax, ebx, ecx, edx; > + > + VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); > + BUG_ON(!ecx); > + calibration_result = ecx / HZ; > + > + printk(KERN_INFO "APIC bus freq read from hypervisor : %u.%03u MHz\n", > + calibration_result / (1000000 / HZ), > + calibration_result % (1000000 / HZ)); > + return calibration_result; > +} > + > 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_platform.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"); > } > > /* > Index: linux-x86-tree.git/arch/x86/kernel/x86_init.c > =================================================================== > --- linux-x86-tree.git.orig/arch/x86/kernel/x86_init.c 2010-08-17 15:29:21.000000000 -0700 > +++ linux-x86-tree.git/arch/x86/kernel/x86_init.c 2010-08-17 16:44:20.000000000 -0700 > @@ -95,7 +95,8 @@ struct x86_platform_ops x86_platform = { > .iommu_shutdown = iommu_shutdown_noop, > .is_untracked_pat_range = is_ISA_range, > .nmi_init = default_nmi_init, > - .i8042_detect = default_i8042_detect > + .i8042_detect = default_i8042_detect, > + .calibrate_apic = native_calibrate_apic > }; > > EXPORT_SYMBOL_GPL(x86_platform); >