Subject: Re: [PATCH v2 2/4] m68k: use asm-generic/memory_model.h for both MMU and !MMU

From: Guenter Roeck <[email-masked]>
Date: Sun, 12 Feb 2023 09:35:13 -0800

Hi,

On Sun, Jan 29, 2023 at 02:42:33PM +0200, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[email-masked]>
> 
> The MMU variant uses generic definitions of page_to_pfn() and
> pfn_to_page(), but !MMU defines them in include/asm/page_no.h for no
> good reason.
> 
> Include asm-generic/memory_model.h in the common include/asm/page.h and
> drop redundant definitions.
> 
> Signed-off-by: Mike Rapoport (IBM) <[email-masked]>
> Reviewed-by: Geert Uytterhoeven <[email-masked]>
> Acked-by: Geert Uytterhoeven <[email-masked]>

This patch results in a boot failure when trying to boot the mcf5208evb qemu
emulation. Reverting it together with "mm, arch: add generic implementation
of pfn_valid() for FLATMEM" fixes the problem. There is no error log - the
emulation hangs silently until aborted.

Guenter

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# bad: [6ba8a227fd19d19779005fb66ad7562608e1df83] Add linux-next specific files for 20230210
# good: [4ec5183ec48656cec489c49f989c508b68b518e3] Linux 6.2-rc7
git bisect start 'HEAD' 'v6.2-rc7'
# good: [94613f0efc69ed41f9229ef5c294db3ec37145da] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git
git bisect good 94613f0efc69ed41f9229ef5c294db3ec37145da
# good: [19e62c715fe70dae4582c2874ed3e66715d09af6] Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
git bisect good 19e62c715fe70dae4582c2874ed3e66715d09af6
# good: [5d8b7ecef7f4a681b6e5538db59ff26c389c0ab6] Merge branch 'for-next' of https://gitlab.com/peda-linux/mux.git
git bisect good 5d8b7ecef7f4a681b6e5538db59ff26c389c0ab6
# good: [c349bf6ec83903b20fe570c5609b9a864a64e09c] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/krisman/unicode.git
git bisect good c349bf6ec83903b20fe570c5609b9a864a64e09c
# good: [5a06a9f17454df38f35672be522ff5eb9b4277d2] selftest: add testing unsharing and counting ksm zero page
git bisect good 5a06a9f17454df38f35672be522ff5eb9b4277d2
# bad: [f5d115a7b06e5661ed5218ffa9a2644c4ff1c135] Merge branch 'mm-nonmm-unstable' into mm-everything
git bisect bad f5d115a7b06e5661ed5218ffa9a2644c4ff1c135
# bad: [acb018d6ea0c055381fba7dddaef386ee28f8075] mm/vmalloc.c: allow vread() to read out vm_map_ram areas
git bisect bad acb018d6ea0c055381fba7dddaef386ee28f8075
# good: [1a5d9782ac969dc6e61c6786500b5160603188ea] mm/mmap: remove __vma_adjust()
git bisect good 1a5d9782ac969dc6e61c6786500b5160603188ea
# good: [4b32363697de957dcc890b6245bec3f58903639a] arm: include asm-generic/memory_model.h from page.h rather than memory.h
git bisect good 4b32363697de957dcc890b6245bec3f58903639a
# bad: [328cf3fa6682ce6a4de6f8bb8009c833dc33f3c8] mm/migrate: convert isolate_movable_page() to use folios
git bisect bad 328cf3fa6682ce6a4de6f8bb8009c833dc33f3c8
# bad: [b704c765b08cabe82adf76a4d1a74f3688eee410] mm/mempolicy: convert queue_pages_pmd() to queue_folios_pmd()
git bisect bad b704c765b08cabe82adf76a4d1a74f3688eee410
# bad: [e5734c8b0edfd2a053a5c256189586a3b1e9f63d] mm, arch: add generic implementation of pfn_valid() for FLATMEM
git bisect bad e5734c8b0edfd2a053a5c256189586a3b1e9f63d
# bad: [ad8aecea034c591b9754bc5908da9719853aa7fa] mips: drop definition of pfn_valid() for DISCONTIGMEM
git bisect bad ad8aecea034c591b9754bc5908da9719853aa7fa
# bad: [1f6271a0dfdf952c2e3981f424784d48f243a2be] m68k: use asm-generic/memory_model.h for both MMU and !MMU
git bisect bad 1f6271a0dfdf952c2e3981f424784d48f243a2be
# first bad commit: [1f6271a0dfdf952c2e3981f424784d48f243a2be] m68k: use asm-generic/memory_model.h for both MMU and !MMU