asm-generic: Fix build when __set_fixmap is absent

On Tue, Feb 09, 2016 at 04:52:34PM +0000, Catalin Marinas wrote:
> On Tue, Feb 09, 2016 at 04:33:34PM +0000, Mark Rutland wrote:

> > > >> include/asm-generic/fixmap.h:72:6: error: conflicting types for '__set_fixmap'

> > >     void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);

> > >          ^

> > >    In file included from arch/um/include/asm/pgtable.h:11:0,

> > >                     from include/linux/mm.h:67,

> > >                     from include/linux/ring_buffer.h:5,

> > >                     from include/linux/trace_events.h:5,

> > >                     from include/trace/syscall.h:6,

> > >                     from include/linux/syscalls.h:81,

> > >                     from init/main.c:18:

> > >    arch/um/include/asm/fixmap.h:39:13: note: previous declaration of '__set_fixmap' was here

> > >     extern void __set_fixmap (enum fixed_addresses idx,

> > >                 ^

> > 

> > The conflict is the type of 'phys'. In arch/um that's an unsigned long

> > rather than a phys_addr_t as it is elsewhere.

> 

> At a quick grep, we also have:

> 

> arch/sh/include/asm/fixmap.h

> arch/sh/mm/init.c

> arch/sh/mm/nommu.c

> 

> > If I convert that to a phys_addr_t the build goes along happily.

> > 

> > Should we change set_fixmap_offset back to a macro function for now, or

> > is it simple/correct to change arch/um to use phys_addr_t in

> > __set_fixmap?

> 

> And sh. I prefer the static inline, though there is more effort needed

> to test and get acks ;) (I really don't mind either way).


I would also prefer to make this a static inline, but it looks like we
need to sort out some cross-architecture cleanup first. I'm happy to
have a go at that.

In the meantime, so as to allow linux-next to build, and to save us from
merge hell, let's follow the usual idiom and hope that underscores will
protect us.

Hopefully this is the last time I ask this today: Arnd, Catalin, are you
happy with the below patch?

Mark.

---->8----
From 6d283603d18071690dc138e4a0591a445a1d1e30 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>

Date: Tue, 9 Feb 2016 17:08:26 +0000
Subject: [PATCH] asm-generic: make __set_fixmap_offset a macro again

Turning __set_fixmap_offset into a static inline breaks the build for
several architectures. Fixing this properly requires updates to a number
of architectures to make them agree on the prototype of __set_fixmap.

For the timebeing, restore __set_fixmap_offset to its prior state as a
macro function, reverting commit ac4c0ac73485867c ("asm-generic: make
__set_fixmap_offset a static inline"). To avoid the original issue with
namespace clashes, 'addr' is prefixed with a liberal sprinking of
underscores.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
---
 include/asm-generic/fixmap.h | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

-- 
1.9.1

On Tue, Feb 09, 2016 at 05:21:26PM +0000, Mark Rutland wrote:
> From 6d283603d18071690dc138e4a0591a445a1d1e30 Mon Sep 17 00:00:00 2001

> From: Mark Rutland <mark.rutland@arm.com>

> Date: Tue, 9 Feb 2016 17:08:26 +0000

> Subject: [PATCH] asm-generic: make __set_fixmap_offset a macro again

> 

> Turning __set_fixmap_offset into a static inline breaks the build for

> several architectures. Fixing this properly requires updates to a number

> of architectures to make them agree on the prototype of __set_fixmap.

> 

> For the timebeing, restore __set_fixmap_offset to its prior state as a

> macro function, reverting commit ac4c0ac73485867c ("asm-generic: make

> __set_fixmap_offset a static inline"). To avoid the original issue with

> namespace clashes, 'addr' is prefixed with a liberal sprinking of

> underscores.

> 

> Signed-off-by: Mark Rutland <mark.rutland@arm.com>

> Cc: Arnd Bergmann <arnd@arndb.de>

> Cc: Catalin Marinas <catalin.marinas@arm.com>

> ---

>  include/asm-generic/fixmap.h | 14 +++++++-------

>  1 file changed, 7 insertions(+), 7 deletions(-)

> 

> diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h

> index f9c27b6..827e4d3 100644

> --- a/include/asm-generic/fixmap.h

> +++ b/include/asm-generic/fixmap.h

> @@ -70,13 +70,13 @@ static inline unsigned long virt_to_fix(const unsigned long vaddr)

>  #endif

>  

>  /* Return a pointer with offset calculated */

> -static inline unsigned long __set_fixmap_offset(enum fixed_addresses idx,

> -						phys_addr_t phys,

> -						pgprot_t flags)

> -{

> -	__set_fixmap(idx, phys, flags);

> -	return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1));

> -}

> +#define __set_fixmap_offset(idx, phys, flags)				\

> +({									\

> +	unsigned long ________addr;					\

> +	__set_fixmap(idx, phys, flags);					\

> +	________addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1));	\

> +	________addr;							\

> +})

>  

>  #define set_fixmap_offset(idx, phys) \

>  	__set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL)

> -- 

> 1.9.1


It looks fine to me.

-- 
Catalin