linux-kernel - Re: [RESEND][PATCH 1/2] lib/scatterlist: Make ARCH_HAS_SG

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140322225201.GN7528@n2100.arm.linux.org.uk>
Date:	Sat, 22 Mar 2014 22:52:01 +0000
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	James Bottomley <James.Bottomley@...senPartnership.com>
Cc:	Laura Abbott <lauraa@...eaurora.org>,
	Fenghua Yu <fenghua.yu@...el.com>,
	Tony Luck <tony.luck@...el.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-scsi@...r.kernel.org, linux-s390@...r.kernel.org,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	x86@...nel.org, Heiko Carstens <heiko.carstens@...ibm.com>,
	linux-kernel@...r.kernel.org, linux390@...ibm.com,
	sparclinux@...r.kernel.org, Ingo Molnar <mingo@...hat.com>,
	Paul Mackerras <paulus@...ba.org>,
	"H. Peter Anvin" <hpa@...or.com>,
	Martin Schwidefsky <schwidefsky@...ibm.com>,
	linux-ia64@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	linuxppc-dev@...ts.ozlabs.org,
	"David S. Miller" <davem@...emloft.net>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [RESEND][PATCH 1/2] lib/scatterlist: Make ARCH_HAS_SG_CHAIN an
	actual Kconfig

On Sat, Mar 22, 2014 at 03:37:40PM -0700, James Bottomley wrote:
> On Sat, 2014-03-22 at 22:23 +0000, Russell King - ARM Linux wrote:
> > On Sat, Mar 22, 2014 at 02:31:21PM -0700, James Bottomley wrote:
> > > Perhaps now might be the time to ask which are the remaining
> > > architectures that cannot do SG chaining and then we can fix them and
> > > pull the whole thing out.
> > 
> > Not quite.  You're making the assumption that we can be sure that all
> > the scatterlist users on an architecture have been converted - that's
> > simply not true on ARM.
> 
> No I'm not, I said "now might be the time to ask which are the remaining
> architectures that cannot do SG chaining"

And I'm disagreeing with that statement which implies that it's something
that is an architecture wide property for any particular architecture.

Right now in mainline, if ARM has IOMMU support enabled, then SG_CHAIN
support will also be enabled.  I've a patch out of tree which I've been
using for years which enables SG_CHAIN for a particular SoC (Dove).
Otherwise, it doesn't have support for SG_CHAIN.

PARISC on the other hand (as you list) has no support to enable SG_CHAIN
under any circumstances.

Where we're disagreeing is whether this is something that is always-on or
always-off for any particular architecture.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.
--
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/