linux-kernel - Re: [PATCH RFC] usb: gadget: Add xilinx axi usb2 device support

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:	Fri, 21 Feb 2014 17:15:04 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	monstr@...str.eu
Cc:	balbi@...com, Mark Rutland <mark.rutland@....com>,
	Subbaraya Sundeep Bhatta <subbaraya.sundeep.bhatta@...inx.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Subbaraya Sundeep Bhatta <sbhatta@...inx.com>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>
Subject: Re: [PATCH RFC] usb: gadget: Add xilinx axi usb2 device support

On Friday 21 February 2014 16:51:07 Michal Simek wrote:
> > | 
> > |     if (res->flags & IORESOURCE_CACHEABLE)
> > |             dest_ptr = devm_ioremap(dev, res->start, size);
> > |     else
> > |             dest_ptr = devm_ioremap_nocache(dev, res->start, size);
> 
> I have read it just not sure if IORESOURCE_CACHEABLE is setup by default
> or not.
> If yes, then you have to setup res->flags in your driver and have to
> check it.

ioremap() and ioremap_nocache() are the same on all architectures.
If you want a cacheable mapping, you need to call ioremap_cache(),
which unfortunately doesn't exist on all architectures and also
doesn't have a devm_* variant.

I don't know how the above code made it into devm_ioremap_resource(),
it's clearly bogus. The only time we ever set IORESOURCE_CACHEABLE
is for ROM BARs on PCI, which in turn are rarely used in the kernel.
It's never set for any platform devices, aside from one use
in arch/arm/mach-clps711x/board-cdb89712.c.

	Arnd
--
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/