lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 23 Aug 2010 17:12:04 -0700
From:	Alok Kataria <akataria@...are.com>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	the arch/x86 maintainers <x86@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86, apic: Add apic calibration hook.


On Wed, 2010-08-18 at 12:27 -0700, Alok Kataria wrote:
> 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.
> 

Any comments on this one ? 

Thanks in advance. 
Alok

> Signed-off-by: Alok N Kataria <akataria@...are.com>
> Cc: H. Peter Anvin <hpa@...or.com>
> 
> 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 <akataria@...are.com>
> > Cc: H. Peter Anvin <hpa@...or.com>
> > 
> > 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@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists