Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752464Ab0HRRx6 (ORCPT ); Wed, 18 Aug 2010 13:53:58 -0400 Received: from smtp-outbound-2.vmware.com ([65.115.85.73]:13707 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752186Ab0HRRx4 (ORCPT ); Wed, 18 Aug 2010 13:53:56 -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 10:53:55 -0700 Message-Id: <1282154035.15158.48.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 Content-Length: 7861 Lines: 218 On Wed, 2010-08-18 at 10:41 -0700, Alok Kataria wrote: > Add a new function pointer calibrate_apic to x86_platform_ops. I guess I should move this in init_ops too, anything else that needs to be changed ? Thanks, Alok > 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); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/