[Debian] [Fwd: [PATCH] Fix speedstep-centino driver in VCPU presence]

[Ola Lundqvist]

Hi Kiril

Thanks. Do this apply to the Debian kernel or is it against the
vanilla kernel?

Regards,

// Ola

On Thu, Apr 26, 2007 at 04:15:06PM +0400, Kirill Korotaev wrote:
> Ola,
> 
> FYI, debian bug 420708 will be fixed in 2.6.18-028stab031
> patch attached.
> 
> Thanks,
> Kirill
> 
> 
> -------- Original Message --------
> Subject: [PATCH] Fix speedstep-centino driver in VCPU presence
> Date: Thu, 26 Apr 2007 14:35:45 +0400
> From: Alexey Dobriyan <adobriyan at sw.ru>
> To: dev at sw.ru
> CC: vz at sw.ru
> 
> Patch from Alexey Dobriyan (adobriyan@)
> 
> speedstep-centrino cpufreq driver was using set_cpus_allowed() and
> checks for smp_processor_id() to confine itself to given CPU. In
> presence of VCPU freature this doesn't work.
> 
> Switch to rdmsr_on_cpu/wrmsr_on_cpu() infrastructure.
> 
> Closes http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=420708
> 

> --- a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
> +++ b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
> @@ -17,7 +17,6 @@ #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/init.h>
>  #include <linux/cpufreq.h>
> -#include <linux/sched.h>	/* current */
>  #include <linux/delay.h>
>  #include <linux/compiler.h>
>  
> @@ -319,14 +318,8 @@ static unsigned int get_cur_freq(unsigne
>  {
>  	unsigned l, h;
>  	unsigned clock_freq;
> -	cpumask_t saved_mask;
>  
> -	saved_mask = current->cpus_allowed;
> -	set_cpus_allowed(current, cpumask_of_cpu(cpu));
> -	if (smp_processor_id() != cpu)
> -		return 0;
> -
> -	rdmsr(MSR_IA32_PERF_STATUS, l, h);
> +	rdmsr_on_cpu(cpu, MSR_IA32_PERF_STATUS, &l, &h);
>  	clock_freq = extract_clock(l, cpu, 0);
>  
>  	if (unlikely(clock_freq == 0)) {
> @@ -336,11 +329,10 @@ static unsigned int get_cur_freq(unsigne
>  		 * P-state transition (like TM2). Get the last freq set 
>  		 * in PERF_CTL.
>  		 */
> -		rdmsr(MSR_IA32_PERF_CTL, l, h);
> +		rdmsr_on_cpu(cpu, MSR_IA32_PERF_CTL, &l, &h);
>  		clock_freq = extract_clock(l, cpu, 1);
>  	}
>  
> -	set_cpus_allowed(current, saved_mask);
>  	return clock_freq;
>  }
>  
> @@ -550,15 +542,15 @@ static int centrino_cpu_init(struct cpuf
>  
>  	/* Check to see if Enhanced SpeedStep is enabled, and try to
>  	   enable it if not. */
> -	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
> +	rdmsr_on_cpu(policy->cpu, MSR_IA32_MISC_ENABLE, &l, &h);
>  
>  	if (!(l & (1<<16))) {
>  		l |= (1<<16);
>  		dprintk("trying to enable Enhanced SpeedStep (%x)\n", l);
> -		wrmsr(MSR_IA32_MISC_ENABLE, l, h);
> +		wrmsr_on_cpu(policy->cpu, MSR_IA32_MISC_ENABLE, l, h);
>  
>  		/* check to see if it stuck */
> -		rdmsr(MSR_IA32_MISC_ENABLE, l, h);
> +		rdmsr_on_cpu(policy->cpu, MSR_IA32_MISC_ENABLE, &l, &h);
>  		if (!(l & (1<<16))) {
>  			printk(KERN_INFO PFX "couldn't enable Enhanced SpeedStep\n");
>  			return -ENODEV;
> @@ -638,7 +630,6 @@ static int centrino_target (struct cpufr
>  	unsigned int	msr, oldmsr = 0, h = 0, cpu = policy->cpu;
>  	struct cpufreq_freqs	freqs;
>  	cpumask_t		online_policy_cpus;
> -	cpumask_t		saved_mask;
>  	cpumask_t		set_mask;
>  	cpumask_t		covered_cpus;
>  	int			retval = 0;
> @@ -662,7 +653,6 @@ #else
>  	online_policy_cpus = policy->cpus;
>  #endif
>  
> -	saved_mask = current->cpus_allowed;
>  	first_cpu = 1;
>  	cpus_clear(covered_cpus);
>  	for_each_cpu_mask(j, online_policy_cpus) {
> @@ -676,8 +666,7 @@ #endif
>  		else
>  			cpu_set(j, set_mask);
>  
> -		set_cpus_allowed(current, set_mask);
> -		if (unlikely(!cpu_isset(smp_processor_id(), set_mask))) {
> +		if (unlikely(!cpu_isset(j, set_mask))) {
>  			dprintk("couldn't limit to CPUs in this domain\n");
>  			retval = -EAGAIN;
>  			if (first_cpu) {
> @@ -690,7 +679,7 @@ #endif
>  		msr = centrino_model[cpu]->op_points[newstate].index;
>  
>  		if (first_cpu) {
> -			rdmsr(MSR_IA32_PERF_CTL, oldmsr, h);
> +			rdmsr_on_cpu(j, MSR_IA32_PERF_CTL, &oldmsr, &h);
>  			if (msr == (oldmsr & 0xffff)) {
>  				dprintk("no change needed - msr was and needs "
>  					"to be %x\n", oldmsr);
> @@ -717,7 +706,7 @@ #endif
>  			oldmsr |= msr;
>  		}
>  
> -		wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
> +		wrmsr_on_cpu(j, MSR_IA32_PERF_CTL, oldmsr, h);
>  		if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
>  			break;
>  
> @@ -739,8 +728,7 @@ #endif
>  
>  		if (!cpus_empty(covered_cpus)) {
>  			for_each_cpu_mask(j, covered_cpus) {
> -				set_cpus_allowed(current, cpumask_of_cpu(j));
> -				wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
> +				wrmsr_on_cpu(j, MSR_IA32_PERF_CTL, oldmsr, h);
>  			}
>  		}
>  
> @@ -755,7 +743,6 @@ #endif
>  	}
>  
>  migrate_end:
> -	set_cpus_allowed(current, saved_mask);
>  	return 0;
>  }
>  
> 

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-- 
 --------------------- Ola Lundqvist ---------------------------
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