linux-kernel - Re: [PATCH] ARM: Gemini: Add support for PCI BUS

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

Date:	Mon, 29 Nov 2010 21:57:23 +0200
From:	Paulius Zaleckas <paulius.zaleckas@...il.com>
To:	Russell King - ARM Linux <linux@....linux.org.uk>
CC:	Arnd Bergmann <arnd@...db.de>,
	linux-arm-kernel@...ts.infradead.org,
	Hans Ulli Kroll <ulli.kroll@...glemail.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ARM: Gemini: Add support for PCI BUS

On 11/29/2010 09:32 PM, Russell King - ARM Linux wrote:
> On Mon, Nov 29, 2010 at 06:05:07PM +0200, Paulius Zaleckas wrote:
>> No he really should NOT use readl/writel. The ONLY difference
>> between readl/writel and __raw_readl/__raw_writel is endianess
>> conversion. __raw_*l is not doing it. Which to use depend only
>> on HW.
>
> Wrong.  readl/writel have barriers too to guarantee ordering between
> device accesses and memory accesses.  (device accesses are already
> ordered with respect to themselves.)  __raw variants do not
> guarantee the relative ordering between memory accesses and device
> accesses.

#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
#define __iormb()		rmb()
#define __iowmb()		wmb()
#else
#define __iormb()		do { } while (0)
#define __iowmb()		do { } while (0)
#endif

CONFIG_ARM_DMA_MEM_BUFFERABLE is NOT defined in this case.
I don't see any other barriers.
readl does endianess conversion. What to do if you don't need it?
Do it one more time?
--
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/