From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC] [PATCH] [MTD] Update internal API to support 64-bit device size From: Artem Bityutskiy To: David Woodhouse In-Reply-To: <4912EE49.4070202@nokia.com> References: <4912EE49.4070202@nokia.com> Content-Type: text/plain; charset=UTF-8 Date: Fri, 14 Nov 2008 14:05:06 +0200 Message-Id: <1226664306.16925.96.camel@sauron> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Cc: "linux-mtd@lists.infradead.org" , Adrian Hunter Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2008-11-06 at 15:16 +0200, Adrian Hunter wrote: > MTD internal API presently uses 32-bit values to represent > device size. This patch updates them to 64-bits but leaves > the external API unchanged. Extending the external API > is a separate issue for several reasons. First, no one > needs it at the moment. Secondly, whether the implementation > is done with IOCTLs, sysfs or both is still debated. Thirdly > external API changes require the internal API to be accepted > first. >=20 > Note that although the MTD API will be able to support 64-bit > device sizes, existing drivers do not and are not required > to do so, although NAND base has been updated. >=20 > In general, changing from 32-bit to 64-bit values cause little > or no changes to the majority of the code with the following > exceptions: > - printk message formats > - division and modulus of 64-bit values > - NAND base support > - 32-bit local variables used by mtdpart and mtdconcat > - naughtily assuming one structure maps to another > in MEMERASE ioctl >=20 > Signed-off-by: Adrian Hunter Except of the minor issues (well, this is _RFC_), I support this patch. I think it is a very good step towards 64-bit MTD support. David, could you please look at this rather earlier than later, so we would have time to fix and test this, because the patch touches (slightly though) a lot of files. I've included this and other nandsim patches to ubifs-2.6.git so that we would test the patch more. Adrian ran UBIFS on 8GiB nandsim device (backed to a file) and it works fine. --=20 Best regards, Artem Bityutskiy (=D0=91=D0=B8=D1=82=D1=8E=D1=86=D0=BA=D0=B8=D0=B9 =D0=90= =D1=80=D1=82=D1=91=D0=BC)