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

[Guenter Roeck <linux@roeck-us.net>]

Hi,

On Sun, Jan 29, 2023 at 02:42:33PM +0200, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <rppt@kernel.org>
> 
> 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) <rppt@kernel.org>
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

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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# good: [5a06a9f17454df38f35672be522ff5eb9b4277d2] selftest: add testing unsharing and counting ksm zero page
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# bad: [f5d115a7b06e5661ed5218ffa9a2644c4ff1c135] Merge branch 'mm-nonmm-unstable' into mm-everything
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# good: [1a5d9782ac969dc6e61c6786500b5160603188ea] mm/mmap: remove __vma_adjust()
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# good: [4b32363697de957dcc890b6245bec3f58903639a] arm: include asm-generic/memory_model.h from page.h rather than memory.h
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# bad: [328cf3fa6682ce6a4de6f8bb8009c833dc33f3c8] mm/migrate: convert isolate_movable_page() to use folios
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# bad: [b704c765b08cabe82adf76a4d1a74f3688eee410] mm/mempolicy: convert queue_pages_pmd() to queue_folios_pmd()
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# bad: [e5734c8b0edfd2a053a5c256189586a3b1e9f63d] mm, arch: add generic implementation of pfn_valid() for FLATMEM
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# bad: [ad8aecea034c591b9754bc5908da9719853aa7fa] mips: drop definition of pfn_valid() for DISCONTIGMEM
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# bad: [1f6271a0dfdf952c2e3981f424784d48f243a2be] m68k: use asm-generic/memory_model.h for both MMU and !MMU
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# first bad commit: [1f6271a0dfdf952c2e3981f424784d48f243a2be] m68k: use asm-generic/memory_model.h for both MMU and !MMU