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Date: Tue, 9 Jun 2015 10:23:06 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Huang Rui <ray.huang@amd.com>
Cc: Borislav Petkov <bp@suse.de>, Andy Lutomirski <luto@amacapital.net>,
        Thomas Gleixner <tglx@linutronix.de>,
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        Tony Li <tony.li@amd.com>, Ken Xue <ken.xue@amd.com>
Subject: Re: [PATCH v2 1/4] x86, mwaitt: add monitorx and mwaitx instruction
Message-ID: <20150609082306.GN3644@twins.programming.kicks-ass.net>
References: <1433819621-15093-1-git-send-email-ray.huang@amd.com>
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On Tue, Jun 09, 2015 at 11:13:38AM +0800, Huang Rui wrote:
> 
> MWAITX ECX[1]: enable timer if set
> MWAITX EBX[31:0]: max wait time expressed in SW P0 clocks
> 
> The software P0 frequency is the same as the TSC frequency.
> 
> Max timeout = EBX/(TSC frequency)

^ that, would make a lovely comment for this v

> +static inline void __mwaitx(unsigned long eax, unsigned long ebx,
> +			    unsigned long ecx)
> +{
> +	/* "mwaitx %eax, %ebx, %ecx;" */
> +	asm volatile(".byte 0x0f, 0x01, 0xfb;"
> +		     :: "a" (eax), "b" (ebx), "c" (ecx));
> +}