On 2017-09-05 at 17:11:50 +0200, Arnd Bergmann [off-list ref] wrote:

On Tue, Sep 5, 2017 at 1:27 PM, Tobias Klauser [off-list ref] wrote:

quoted

Including linux/vmalloc.h in asm-generic/io.h isn't necessary since none
of the definitions are used in the header itself. Remove the include in
order to avoid potential header dependency problems if other headers
rely on implict inclusion of linux/vmalloc.h which means that changes
there could break unrelated parts.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
---
 include/asm-generic/io.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index b4531e3b2120..d2d3bd163f5f 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h

@@ -764,7 +764,6 @@ static inline void iowrite64_rep(volatile void __iomem *addr,

 #ifdef __KERNEL__

-#include <linux/vmalloc.h>
 #define __io_virt(x) ((void __force *)(x))

 #ifndef CONFIG_GENERIC_IOMAP

This seems like a good idea in principle, but I think it needs to be tested
well before we apply it, to avoid breaking random drivers that forgot to
add their own includes of that header.

Yes, this certainly needs extensive testing. I already did several
randconfig builds on multiple platforms locally. Also, I sent the same
patch a while ago to LKML already as a fix (which wasn't sufficient) [1]
in order to get the kbuild test bot to test it ;)

  [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1392578.html

And indeed, the kbuild test bot failed on multiple drivers as a result
of me submitting this patch back then and I successively sent patches to
fix the fallout. Now all of them are merged.

I've added your patch to my testing queue, but not to the asm-generic
tree now. We should see if it leads to any randconfig build regressions
on the architectures I normally test.

Thanks!

Did you run into a specific problem with the #include, or did it just occur
to you that it might help in general?

See above. Sorry, I should have mentioned it in the original patch
submission but I forgot about the full history and only tried to
reconstruct it now that you asked ;)

Tobias