From: "Pali Rohár" <pali@kernel.org>
To: linux-mm@kvack.org
Cc: Ash Logan <ash@heyquark.com>,
paulus@samba.org, mpe@ellerman.id.au,
christophe.leroy@csgroup.eu, robh+dt@kernel.org,
benh@kernel.crashing.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, j.ne@posteo.net
Subject: Re: [PATCH 11/12] powerpc: wiiu: don't enforce flat memory
Date: Fri, 20 May 2022 14:30:02 +0200 [thread overview]
Message-ID: <20220520123002.rd46p5ty6wumi7cc@pali> (raw)
In-Reply-To: <935b426a-6c64-beb0-907f-8c3f0a089ab7@heyquark.com>
+ linux-mm
Do you know what are requirements for kernel to support non-contiguous
memory support and what is needed to enable it for 32-bit powerpc?
Currently powerpc arch code does not support "memblock.memory.cnt > 1"
except for WII which seems like a hack... See below.
On Friday 20 May 2022 20:44:04 Ash Logan wrote:
> On 20/5/22 18:04, Pali Rohár wrote:
> > On Friday 20 May 2022 13:41:04 Ash Logan wrote:
> >> On 14/5/22 08:43, Pali Rohár wrote:
> >>> On Wednesday 02 March 2022 15:44:05 Ash Logan wrote:
> >>>> pgtable_32.c:mapin_ram loops over each valid memory range, which means
> >>>> non-contiguous memory just works.
> >>>
> >>> Hello! Does it mean that non-contiguous memory works for any 32-bit
> >>> powerpc platform, and not only for wiiu? If yes, should not be
> >>> non-contiguous memory support enabled for all 32-bit ppc boards then?
> >>
> >> Hi! Sorry for my delayed response. As best I can tell, it does indeed
> >> Just Work, but I have only been able to test on wiiu which is missing a
> >> lot of features other boards have (like PCI) - so it's possible there's
> >> still an assumption elsewhere in the kernel that I haven't hit.
> >>
> >> As best I can tell, the Wii and Wii U are the only 32-bit powerpc boards
> >> out there where it's even possible to have non-contiguous memory.
> >
> > What is the reason that those two boards are the **only**? Is there some
> > specific requirement from bootloader or hardware to "enable"
> > non-contiguous memory support?
>
> Not that I know of, I was just saying that I was only aware of those two
> boards where the memory map isn't contiguous, and that is the only place
> where it has been tested. Evidently you know of another board!
>
> > I'm interested in enabling non-contiguous memory support for P2020-based
> > board as it has gaps in its 32-bit memory layout and which could be used
> > for RAM mapping when 4GB DDR3 module is plugged in (default is 2GB).
>
> If it's like the Wii or Wii U (some memory at 0, a gap for MMIO or
> whatever, then more memory at a higher address) then you should try a
> patch along these lines, because barring the unknowns I mentioned before
> it should work. At least as far as I'm aware ;)
>
> >>>> Signed-off-by: Ash Logan <ash@heyquark.com>
> >>>> ---
> >>>> arch/powerpc/mm/init_32.c | 4 ++--
> >>>> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>>>
> >>>> diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
> >>>> index 3d690be48e84..59a84629d9a0 100644
> >>>> --- a/arch/powerpc/mm/init_32.c
> >>>> +++ b/arch/powerpc/mm/init_32.c
> >>>> @@ -125,10 +125,10 @@ void __init MMU_init(void)
> >>>> * lowmem_end_addr is initialized below.
> >>>> */
> >>>> if (memblock.memory.cnt > 1) {
> >>>> -#ifndef CONFIG_WII
> >>>> +#if !defined(CONFIG_WII) && !defined(CONFIG_WIIU)
> >>>> memblock_enforce_memory_limit(memblock.memory.regions[0].size);
> >>>> pr_warn("Only using first contiguous memory region\n");
> >>>> -#else
> >>>> +#elif defined(CONFIG_WII)
> >>>> wii_memory_fixups();
> >>>> #endif
> >>>> }
> >>>> --
> >>>> 2.35.1
> >>>>
next prev parent reply other threads:[~2022-05-20 12:30 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-02 4:43 [PATCH 00/12] powerpc: Nintendo Wii U support Ash Logan
2022-03-02 4:43 ` [PATCH 01/12] dt-bindings: wiiu: Document the Nintendo Wii U devicetree Ash Logan
2022-03-02 13:28 ` Rob Herring
2022-03-02 4:43 ` [PATCH 02/12] powerpc: wiiu: device tree Ash Logan
2022-03-02 13:36 ` Rob Herring
2022-03-03 2:41 ` Ash Logan
2022-03-02 4:43 ` [PATCH 03/12] powerpc: wiiu: bootwrapper support Ash Logan
2022-03-02 4:43 ` [PATCH 04/12] powerpc: wiiu: introduce wiiu platform Ash Logan
2022-03-02 4:43 ` [PATCH 05/12] powerpc: wiiu: declare as non-coherent Ash Logan
2022-03-02 4:44 ` [PATCH 06/12] powerpc: wiiu: udbg support for latteipc Ash Logan
2022-03-02 4:44 ` [PATCH 07/12] powerpc: wiiu: espresso interrupt controller support Ash Logan
2022-03-02 4:44 ` [PATCH 08/12] powerpc: wiiu: latte " Ash Logan
2022-03-02 4:44 ` [PATCH 09/12] powerpc: espresso processor support Ash Logan
2022-03-02 4:44 ` [PATCH 10/12] powerpc: wiiu: platform support Ash Logan
2022-03-02 4:44 ` [PATCH 11/12] powerpc: wiiu: don't enforce flat memory Ash Logan
2022-05-13 22:43 ` Pali Rohár
2022-05-20 3:41 ` Ash Logan
2022-05-20 8:04 ` Pali Rohár
2022-05-20 10:44 ` Ash Logan
2022-05-20 12:30 ` Pali Rohár [this message]
2022-06-09 22:24 ` Pali Rohár
2022-08-08 18:40 ` Pali Rohár
2022-09-08 15:25 ` Christophe Leroy
2022-09-08 15:35 ` Pali Rohár
2022-09-08 20:17 ` Fragmented physical memory on powerpc/32 Pali Rohár
2022-09-10 9:39 ` Christophe Leroy
2022-09-12 14:48 ` Mike Rapoport
2022-09-12 21:16 ` Pali Rohár
2022-09-13 6:11 ` Christophe Leroy
2022-09-13 12:36 ` Christophe Leroy
2022-09-14 9:32 ` Mike Rapoport
2022-09-14 9:43 ` Christophe Leroy
2022-09-14 15:55 ` Mike Rapoport
2022-09-14 19:56 ` Pali Rohár
2022-03-02 4:44 ` [PATCH 12/12] powerpc: wiiu: Add minimal default config Ash Logan
2022-06-22 13:10 ` [PATCH v2 00/12] powerpc: Nintendo Wii U support Ash Logan
2022-06-22 13:10 ` [PATCH v2 01/12] dt-bindings: wiiu: Document the Nintendo Wii U devicetree Ash Logan
2022-06-22 13:10 ` [PATCH v2 02/12] powerpc: wiiu: device tree Ash Logan
2022-06-22 13:10 ` [PATCH v2 03/12] powerpc: wiiu: bootwrapper support Ash Logan
2022-06-22 13:10 ` [PATCH v2 04/12] powerpc: wiiu: introduce wiiu platform Ash Logan
2022-06-22 13:10 ` [PATCH v2 05/12] powerpc: wiiu: declare as non-coherent Ash Logan
2022-06-22 13:10 ` [PATCH v2 06/12] powerpc: wiiu: udbg support for latteipc Ash Logan
2022-06-27 0:15 ` kernel test robot
2022-06-22 13:10 ` [PATCH v2 07/12] powerpc: wiiu: espresso interrupt controller support Ash Logan
2022-06-22 13:10 ` [PATCH v2 08/12] powerpc: wiiu: latte " Ash Logan
2022-06-27 2:51 ` kernel test robot
2022-06-22 13:10 ` [PATCH v2 09/12] powerpc: espresso processor support Ash Logan
2022-06-22 13:10 ` [PATCH v2 10/12] powerpc: wiiu: platform support Ash Logan
2022-06-22 13:10 ` [PATCH v2 11/12] powerpc: wiiu: don't enforce flat memory Ash Logan
2022-06-22 13:10 ` [PATCH v2 12/12] powerpc: wiiu: Add minimal default config Ash Logan
2022-06-28 13:31 ` [PATCH v3 00/12] powerpc: Nintendo Wii U support Ash Logan
2022-06-28 13:31 ` [PATCH v3 01/12] dt-bindings: wiiu: Document the Nintendo Wii U devicetree Ash Logan
2022-06-29 9:52 ` Krzysztof Kozlowski
2022-06-28 13:31 ` [PATCH v3 02/12] powerpc: wiiu: device tree Ash Logan
2022-06-29 9:58 ` Krzysztof Kozlowski
2022-06-29 16:13 ` Segher Boessenkool
2022-06-29 18:13 ` Krzysztof Kozlowski
2022-06-29 20:28 ` Segher Boessenkool
2022-06-28 13:31 ` [PATCH v3 03/12] powerpc: wiiu: bootwrapper support Ash Logan
2022-06-28 13:31 ` [PATCH v3 04/12] powerpc: wiiu: introduce wiiu platform Ash Logan
2022-06-28 13:31 ` [PATCH v3 05/12] powerpc: wiiu: declare as non-coherent Ash Logan
2022-06-28 13:31 ` [PATCH v3 06/12] powerpc: wiiu: udbg support for latteipc Ash Logan
2022-06-28 13:31 ` [PATCH v3 07/12] powerpc: wiiu: espresso interrupt controller support Ash Logan
2022-06-28 13:31 ` [PATCH v3 08/12] powerpc: wiiu: latte " Ash Logan
2022-06-28 13:31 ` [PATCH v3 09/12] powerpc: espresso processor support Ash Logan
2022-06-28 13:31 ` [PATCH v3 10/12] powerpc: wiiu: platform support Ash Logan
2022-06-28 13:31 ` [PATCH v3 11/12] powerpc: wiiu: don't enforce flat memory Ash Logan
2022-06-28 13:31 ` [PATCH v3 12/12] powerpc: wiiu: add minimal default config Ash Logan
2022-11-15 14:47 ` [PATCH v3 00/12] powerpc: Nintendo Wii U support Christophe Leroy
2022-11-19 11:30 ` [PATCH v4 00/11] " Ash Logan
2022-11-19 11:30 ` [PATCH v4 01/11] dt-bindings: wiiu: Document the Nintendo Wii U devicetree Ash Logan
2022-11-19 21:36 ` Rob Herring
2022-11-20 15:30 ` Rob Herring
2024-02-20 16:20 ` Christophe Leroy
2024-02-20 16:24 ` Krzysztof Kozlowski
2022-11-19 11:30 ` [PATCH v4 02/11] powerpc: wiiu: device tree Ash Logan
2022-11-19 11:30 ` [PATCH v4 03/11] powerpc: wiiu: bootwrapper support Ash Logan
2022-11-19 11:30 ` [PATCH v4 04/11] powerpc: wiiu: introduce wiiu platform Ash Logan
2022-11-19 11:30 ` [PATCH v4 05/11] powerpc: wiiu: declare as non-coherent Ash Logan
2022-11-19 11:30 ` [PATCH v4 06/11] powerpc: wiiu: udbg support for latteipc Ash Logan
2022-11-19 11:30 ` [PATCH v4 07/11] powerpc: wiiu: espresso interrupt controller support Ash Logan
2022-11-19 11:30 ` [PATCH v4 08/11] powerpc: wiiu: latte " Ash Logan
2022-11-19 11:30 ` [PATCH v4 09/11] powerpc: espresso processor support Ash Logan
2022-11-19 11:30 ` [PATCH v4 10/11] powerpc: wiiu: platform support Ash Logan
2022-11-19 11:30 ` [PATCH v4 11/11] powerpc: wiiu: add minimal default config Ash Logan
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