Messages in this thread | | | Date | Mon, 29 Nov 2021 21:33:18 +0800 | From | Jisheng Zhang <> | Subject | Re: [PATCH V4 0/2] riscv: add RISC-V Svpbmt Standard Extension supports |
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On Mon, 29 Nov 2021 09:40:05 +0800 wefu@redhat.com wrote:
> From: Fu Wei <wefu@redhat.com> > > This patch follows the RISC-V standard Svpbmt extension in > privilege spec to solve the non-coherent SOC DMA synchronization > issues. > > The svpbmt PTE format: > | 63 | 62-61 | 60-8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 > N MT RSW D A G U X W R V > ^ > > Of the Reserved bits [63:54] in a leaf PTE, the bits [62:61] are used as > the MT (aka MemType) field. This field specifies one of three memory types > as shown in the following table: > MemType RISC-V Description > ---------- ------------------------------------------------ > 00 - PMA Normal Cacheable, No change to implied PMA memory type > 01 - NC Non-cacheable, idempotent, weakly-ordered Main Memory > 10 - IO Non-cacheable, non-idempotent, strongly-ordered I/O memory > 11 - Rsvd Reserved for future standard use > > The standard protection_map[] needn't be modified because the "PMA" > type keeps the highest bits zero. > And the whole modification is limited in the arch/riscv/* and using > a global variable(__svpbmt) as _PAGE_MASK/IO/NOCACHE for pgprot_noncached > (&writecombine) in pgtable.h. We also add _PAGE_CHG_MASK to filter > PFN than before. > > Enable it in devicetree - (Add "riscv,svpbmt" in the mmu of cpu node) > - mmu: > riscv,svpmbt >
I noticed that this series goes up to v4 but changes history is missing. Will you add it?
> Wei Fu (2): > dt-bindings: riscv: add MMU Standard Extensions support for Svpbmt > riscv: add RISC-V Svpbmt extension supports > > .../devicetree/bindings/riscv/cpus.yaml | 10 +++++ > arch/riscv/include/asm/fixmap.h | 2 +- > arch/riscv/include/asm/pgtable-64.h | 21 ++++++++-- > arch/riscv/include/asm/pgtable-bits.h | 39 ++++++++++++++++++- > arch/riscv/include/asm/pgtable.h | 39 ++++++++++++++----- > arch/riscv/kernel/cpufeature.c | 35 +++++++++++++++++ > arch/riscv/mm/init.c | 5 +++ > 7 files changed, 136 insertions(+), 15 deletions(-) >
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