linux-kernel - Re: [PATCH 02/20] powerpc/8xx: Map linear kernel RAM with 8M pages

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] [day] [month] [year] [list]

Date:	Thu, 13 Aug 2015 02:00:43 -0500
From:	Segher Boessenkool <segher@...nel.crashing.org>
To:	Christophe Leroy <christophe.leroy@....fr>
Cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mackerras <paulus@...ba.org>,
	Michael Ellerman <mpe@...erman.id.au>, scottwood@...escale.com,
	linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 02/20] powerpc/8xx: Map linear kernel RAM with 8M pages

On Wed, Aug 12, 2015 at 03:40:56PM +0200, Christophe Leroy wrote:
>  	/* Insert level 1 index */
>  	rlwimi	r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
>  	lwz	r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11)	/* Get the level 1 entry */
> +	mtcr	r11

Maybe mtcrf is faster?  You only want one field, anyhow.

> +	bgt-	cr7,5f		/* CR7.GT = bit 29 = Large page (8M or 512K) */

You can write this as   bt- 29,5f   which should be easier to read.

>  	/* Insert level 1 index */
>  3:	rlwimi	r11, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
>  	lwz	r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11)	/* Get the level 1 entry */
> +	mtcr	r11
> +	bgt	cr7,200f

Same here...  Probably good to comment it, too.


Segher
--
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/