From: greg@kroah.com (Greg KH)
To: kernelnewbies@lists.kernelnewbies.org
Subject: single, comprehensive kernel data types document?
Date: Thu, 21 Apr 2016 11:51:17 +0900 [thread overview]
Message-ID: <20160421025117.GA29694@kroah.com> (raw)
In-Reply-To: <1461184627.2053.6.camel@rtd-VirtualBox>
On Wed, Apr 20, 2016 at 04:37:07PM -0400, Rob Groner wrote:
> Sorry if this isn't related, it seemed like it was...
>
> I recently discovered one of our drivers isn't written correctly for
> 64-bit. It uses a uint32_t to hold an address. Whoops.
>
> In previous drivers when I've needed to hold an address, I've used an
> "unsigned long", as (so far as I could tell) that would give me the
> correct number of bytes whether on 32 or 64-bit systems.
>
> Now that I have to fix this driver, I'd rather do whatever the
> "standard" method is for storing an address value.
>
> Looking at code in the kernel and linux/types.h, I see "phys_addr_t and
> dma_addr_t. Is that what I want to use? What if it's a virtual
> address? void *?
You want to use '__u64' and cast properly within the kernel to a
pointer.
hope this helps,
greg k-h
next prev parent reply other threads:[~2016-04-21 2:51 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-15 12:04 single, comprehensive kernel data types document? Robert P. J. Day
2016-04-15 12:27 ` Greg KH
2016-04-15 12:37 ` John Chludzinski
2016-04-15 13:08 ` Silvan Jegen
2016-04-15 13:09 ` Daniel.
2016-04-15 13:55 ` Greg KH
2016-04-15 16:28 ` Daniel.
2016-04-15 13:53 ` Greg KH
2016-04-15 15:59 ` Nicholas Mc Guire
2016-04-15 16:18 ` Greg KH
2016-04-15 17:07 ` Valdis.Kletnieks at vt.edu
2016-04-15 20:15 ` Greg KH
2016-04-20 20:37 ` Rob Groner
2016-04-21 2:51 ` Greg KH [this message]
2016-04-21 12:51 ` Rob Groner
2016-04-21 19:34 ` Josh Cartwright
2016-04-22 2:37 ` Greg KH
2016-04-22 3:02 ` Valdis.Kletnieks at vt.edu
2016-04-22 3:13 ` Greg KH
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