Messages in this thread | | | Subject | Re: [PATCH 0/6] DISCONTIGMEM support for PPC32 | From | Christophe LEROY <> | Date | Wed, 21 Feb 2018 08:06:10 +0100 |
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Le 20/02/2018 à 17:14, Jonathan Neuschäfer a écrit : > This patchset adds support for DISCONTIGMEM on 32-bit PowerPC. This is > required to properly support the Nintendo Wii's memory layout, in which > there are two blocks of RAM and MMIO in the middle. > > Previously, this memory layout was handled by code that joins the two > RAM blocks into one, reserves the MMIO hole, and permits allocations of > reserved memory in ioremap. This hack didn't work with resource-based > allocation (as used for example in the GPIO driver for Wii[1]), however. > > After this patchset, users of the Wii can either select CONFIG_FLATMEM > to get the old behaviour, or CONFIG_DISCONTIGMEM to get the new > behaviour.
My question might me stupid, as I don't know PCC64 in deep, but when looking at page_is_ram() in arch/powerpc/mm/mem.c, I have the feeling the PPC64 implements ram by blocks. Isn't it what you are trying to achieve ? Wouldn't it be feasible to map to what's done in PPC64 for PPC32 ?
Christophe
> > Some parts of this patchset are probably not ideal (I'm thinking of my > implementation of pfn_to_nid here), and will require some discussion/ > changes. > > [1]: https://www.spinics.net/lists/devicetree/msg213956.html > > Jonathan Neuschäfer (6): > powerpc/mm/32: Use pfn_valid to check if pointer is in RAM > powerpc: numa: Fix overshift on PPC32 > powerpc: numa: Use the right #ifdef guards around functions > powerpc: numa: Restrict fake NUMA enulation to CONFIG_NUMA systems > powerpc: Implement DISCONTIGMEM and allow selection on PPC32 > powerpc: wii: Don't rely on reserved memory hack if DISCONTIGMEM is > set > > arch/powerpc/Kconfig | 5 ++++- > arch/powerpc/include/asm/mmzone.h | 21 +++++++++++++++++++++ > arch/powerpc/mm/numa.c | 18 +++++++++++++++--- > arch/powerpc/mm/pgtable_32.c | 2 +- > arch/powerpc/platforms/embedded6xx/wii.c | 10 +++++++--- > 5 files changed, 48 insertions(+), 8 deletions(-) >
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