Re: [PATCH 06/12] microblaze: use pgtable-nopmd instead of 4level-fixup

From: Mike Rapoport <rppt@kernel.org>
To: Michal Simek <monstr@monstr.eu>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	Anton Ivanov <anton.ivanov@cambridgegreys.com>,
	Arnd Bergmann <arnd@arndb.de>,
	"David S. Miller" <davem@davemloft.net>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Greentime Hu <green.hu@gmail.com>,
	Greg Ungerer <gerg@linux-m68k.org>, Helge Deller <deller@gmx.de>,
	"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
	Jeff Dike <jdike@addtoit.com>,
	"Kirill A. Shutemov" <kirill@shutemov.name>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Mark Salter <msalter@redhat.com>,
	Matt Turner <mattst88@gmail.com>,
	Richard Weinberger <richard@nod.at>,
	Russell King <linux@armlinux.org.uk>,
	Sam Creasey <sammy@sammy.net>, Vincent Chen <deanbo422@gmail.com>,
	Vineet Gupta <Vineet.Gupta1@synopsys.com>,
	linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-c6x-dev@linux-c6x.org, linux-kernel@vger.kernel.org,
	linux-m68k@lists.linux-m68k.org, linux-parisc@vger.kernel.org,
	linux-um@lists.infradead.org, sparclinux@vger.kernel.org,
	Mike Rapoport <rppt@linux.ibm.com>
Subject: Re: [PATCH 06/12] microblaze: use pgtable-nopmd instead of 4level-fixup
Date: Fri, 25 Oct 2019 23:33:19 +0300	[thread overview]
Message-ID: <20191025203318.GA8413@rapoport-lnx> (raw)
In-Reply-To: <aa7df5a1-5022-bc82-8816-74c956e2fd90@monstr.eu>

On Fri, Oct 25, 2019 at 10:24:30AM +0200, Michal Simek wrote:
> Hi Mike,
> 
> On 23. 10. 19 11:28, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> > 
> > microblaze has only two-level page tables and can use pgtable-nopmd and
> > folding of the upper layers.
> > 
> > Replace usage of include/asm-generic/4level-fixup.h and explicit definition
> > of __PAGETABLE_PMD_FOLDED in microblaze with
> > include/asm-generic/pgtable-nopmd.h and adjust page table manipulation
> > macros and functions accordingly.
> > 
> > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> > ---
> >  arch/microblaze/include/asm/page.h    |  3 ---
> >  arch/microblaze/include/asm/pgalloc.h | 16 ----------------
> >  arch/microblaze/include/asm/pgtable.h | 32 ++------------------------------
> >  arch/microblaze/kernel/signal.c       | 10 +++++++---
> >  arch/microblaze/mm/init.c             |  7 +++++--
> >  arch/microblaze/mm/pgtable.c          | 13 +++++++++++--
> >  6 files changed, 25 insertions(+), 56 deletions(-)
> 
> I have take a look at this and when this is applied on the top of
> 5.4-rc2 there is not a problem.
> But as was reported by 0-day there is compilation issue on the top of
> mmotm/master tree and I am able to replicate it.
> It means there are other changes in Andrew's tree which are causing it.

0day is still using an old tree for mmotm:

> url:    https://github.com/0day-ci/linux/commits/Mike-Rapoport/mm-remove-__ARCH_HAS_4LEVEL_HACK/20191025-063009
> base:   git://git.cmpxchg.org/linux-mmotm.git master
> config: microblaze-mmu_defconfig (attached as .config)

A while ago Johannes moved the mmotm to github and the last commit in
git.cmpxchg.org/linux-mmotm.git was in the end of August.

[1] https://lore.kernel.org/linux-mm/20190916134327.GC29985@cmpxchg.org

> Thanks,
> Michal
> 
> -- 
> Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
> w: www.monstr.eu p: +42-0-721842854
> Maintainer of Linux kernel - Xilinx Microblaze
> Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP ARM64 SoCs
> U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP/Versal SoCs
> 

-- 
Sincerely yours,
Mike.