[PATCH 1/5] device: introduce resource structure to simplify resource delaration

Jean-Christophe PLAGNIOL-VILLARD plagnioj at jcrosoft.com
Sat Nov 20 08:58:24 EST 2010


On 14:40 Sat 20 Nov     , Sascha Hauer wrote:
> On Fri, Nov 19, 2010 at 12:30:09PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > On 09:00 Fri 19 Nov     , Sascha Hauer wrote:
> > > Hi J,
> > > 
> > > On Fri, Nov 12, 2010 at 07:18:54PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > > > introdude also some helper to manager them
> > > > 
> > > > and add multi resource per device support
> > > > 
> > > > ram device: use resource structure instead of memory_platform_data
> > > > 
> > > > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> > > 
> > > 
> > > You shouldn't use a resource_size_t type to access registers. This will
> > > lead to problems when we start to support 64bit resource sizes
> > no as resource_size_t is 64 bit aware
> 
> And exactly this is the problem. void * is usually only 32bit on arm.
> This will lead to compiler warnings and sparse isn't happy about
> unsigned long in readl/writel anyway.
IIRC on arm resource_size_t is never 64bit at least on the current ARMvx

> 
> > >. Instead we should introduce a
> > > 
> > > #define resource_size_to_iomem(size) (void __force __iomem *)(size)
> > > 
> > > macro which does the conversion to a void __iomem * type. In a more
> > > advanced version this could also spit a warning when the resource start
> > > is bigger than a pointer type. As an additional plus we'll get rid of
> > > some sparse warnings where map_base is used for readl/writel.
> > we do not do in the kernel and do see the advantage here for the ressource
> > in mind it's in the drivers we need to do it
> > if necessary
> 
> resource_size_t is never passed to readl/writel in the kernel.
yeah but the resources are cast in the drivers

Best Regards,
J.



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