Messages in this thread | | | Date | Mon, 13 Jun 2011 13:00:04 +0900 | From | Paul Mundt <> | Subject | Re: [PATCH] fb.h: ARM uses __raw_{read/write} |
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On Fri, Jun 10, 2011 at 05:31:08PM -0700, H Hartley Sweeten wrote: > ARM provides __raw_{read/write}* functions for memory access. These > should be used instead of the default '(*(volatile' stuff to make sure the > memory accesses are typesafe (void __iomem *). > > This also fixes a number of sparse warning like: > > warning: cast removes address space of expression > > Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> > Cc: Paul Mundt <lethal@linux-sh.org> > Cc: Russell King <linux@arm.linux.org.uk> > I'm not sure what semantics are desirable for ARM here, so I'll wait for Russell to reply.
This wrapping will basically mean that the fb_read/write ops are using __raw_xxx variants while the memset and memcpy wrappers will be using the regular read/write[bwl] routines which contain __iormb() calls. Given that ioread/write and friends all wrap in to the normal versions with the barriers, I would suppose that this is the default behaviour that is desired, as opposed to wrapping in to the __raw_xxx variants directly.
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