linux-kernel - Re: [PATCH 20/30] x86, mm: remove hard-coded ASID limit checks

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Message-ID: <alpine.DEB.2.20.1711202144360.2348@nanos>
Date:   Mon, 20 Nov 2017 21:47:04 +0100 (CET)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Dave Hansen <dave.hansen@...ux.intel.com>
cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        moritz.lipp@...k.tugraz.at, daniel.gruss@...k.tugraz.at,
        michael.schwarz@...k.tugraz.at, richard.fellner@...dent.tugraz.at,
        luto@...nel.org, torvalds@...ux-foundation.org,
        keescook@...gle.com, hughd@...gle.com, x86@...nel.org
Subject: Re: [PATCH 20/30] x86, mm: remove hard-coded ASID limit checks

On Fri, 10 Nov 2017, Dave Hansen wrote:
>  
> +/* There are 12 bits of space for ASIDS in CR3 */
> +#define CR3_HW_ASID_BITS 12
> +/* When enabled, KAISER consumes a single bit for user/kernel switches */
> +#define KAISER_CONSUMED_ASID_BITS 0
> +
> +#define CR3_AVAIL_ASID_BITS (CR3_HW_ASID_BITS-KAISER_CONSUMED_ASID_BITS)

Spaces around '-' please. Same for other operators.

> +/*
> + * ASIDs are zero-based: 0->MAX_AVAIL_ASID are valid.  -1 below
> + * to account for them being zero-absed.  Another -1 is because ASID 0

s/absed/based/

> + * is reserved for use by non-PCID-aware users.
> + */
> +#define MAX_ASID_AVAILABLE ((1<<CR3_AVAIL_ASID_BITS) - 2)
> +
>  /*

Thanks,

	tglx