linux-kernel - Re: [PATCH 3/9] x86/early-quirks: reverse the if ladders

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Message-ID: <alpine.DEB.2.20.1712090002150.2301@nanos>
Date:   Sat, 9 Dec 2017 00:05:07 +0100 (CET)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Matthew Auld <matthew.auld@...el.com>
cc:     intel-gfx@...ts.freedesktop.org,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Ville Syrjälä <ville.syrjala@...ux.intel.com>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        Paulo Zanoni <paulo.r.zanoni@...el.com>,
        Ingo Molnar <mingo@...nel.org>,
        "H . Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/9] x86/early-quirks: reverse the if ladders

On Thu, 7 Dec 2017, Matthew Auld wrote:

> Makes things a little easier to follow.

I disagree. The comment explains gms (what ever that is) in ascending order
and the code has that implemented the same way. Now you change the code to
descending order.

How is that easier to follow? Not at all. That's just crap.

Thanks,

	tglx

>  	 * 0x11 to 0x16: 4MB increments starting at 8MB
>  	 * 0x17 to 0x1d: 4MB increments start at 36MB
>  	 */
> -	if (gms < 0x11)
> -		return gms * MB(32);
> -	else if (gms < 0x17)
> +	if (gms >= 0x17)
> +		return (gms - 0x17) * MB(4) + MB(36);
> +	else if (gms >= 0x11)
>  		return (gms - 0x11) * MB(4) + MB(8);
>  	else
> -		return (gms - 0x17) * MB(4) + MB(36);
> +		return gms * MB(32);
>  }
>  
>  static resource_size_t __init gen9_stolen_size(int num, int slot, int func)
> @@ -443,10 +443,10 @@ static resource_size_t __init gen9_stolen_size(int num, int slot, int func)
>  
>  	/* 0x0  to 0xef: 32MB increments starting at 0MB */
>  	/* 0xf0 to 0xfe: 4MB increments starting at 4MB */
> -	if (gms < 0xf0)
> -		return gms * MB(32);
> -	else
> +	if (gms >= 0xf0)
>  		return (gms - 0xf0) * MB(4) + MB(4);
> +	else
> +		return gms * MB(32);
>  }
>  
>  struct intel_early_ops {
> -- 
> 2.14.3
> 
>