Re: ioremap and dma cleanups and fixes for superh (2nd resend)

Geert Uytterhoeven
2020-07-15T18:21:41Z

On Wed, Jul 15, 2020 at 6:18 PM John Paul Adrian Glaubitz
<glaubitz@physik.fu-berlin.de> wrote:
> On 7/15/20 4:37 PM, John Paul Adrian Glaubitz wrote:
> > Okay, kernel 5.0.0 does not suffer from this bug. So I should be able to bisect
> > this particular issue.
> >
> > I'm glad I don't have to start bisecting with earlier kernels because these
> > won't build easily with my current toolchain based on gcc-9.
> >
> > Will report once I found the bad commit that introduced the problem.
>
> Found the culprit:
>
> c5b27a889da92f4a969d61df77bd4f79ffce57c9 is the first bad commit
> commit c5b27a889da92f4a969d61df77bd4f79ffce57c9
> Author: Peter Zijlstra <peterz@infradead.org>
> Date: Tue Sep 4 14:45:04 2018 +0200
>
> sh/tlb: Convert SH to generic mmu_gather
>
> Generic mmu_gather provides everything SH needs (range tracking and
> cache coherency).
>
> No change in behavior intended.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Nick Piggin <npiggin@gmail.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Rich Felker <dalias@libc.org>
> Cc: Rik van Riel <riel@surriel.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
>
> arch/sh/include/asm/pgalloc.h | 9 +++
> arch/sh/include/asm/tlb.h | 130 +-----------------------------------------
> 2 files changed, 10 insertions(+), 129 deletions(-)
>
> CC'ing the author (Peter Zijlstra <peterz@infradead.org>).

Oh, we actually discussed that:
https://lore.kernel.org/linux-mm/20191204133454.GW2844@hirez.programming.kicks-ass.net/
but there was no conclusion...

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds