[PATCH v7 00/13] riscv: support for Svpbmt and D1 memory types

Heiko Stuebner
2022-03-07T20:53:44Z

Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
for things like non-cacheable pages or I/O memory pages.

So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
types) using the alternatives framework.

This includes a number of changes to the alternatives mechanism itself.
The biggest one being the move to a more central location, as I expect
in the future, nearly every chip needing some sort of patching, be it
either for erratas or for optional features (svpbmt or others).

Detection of the svpbmt functionality is done via Atish's isa extension
handling series [0] and thus does not need any dt-parsing of its own
anymore.

The series also introduces support for the memory types of the D1
which are implemented differently to svpbmt. But when patching anyway
it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
location.

The only slightly bigger difference is that the "normal" type is not 0
as with svpbmt, so kernel patches for this PMA type need to be applied
even before the MMU is brought up, so the series introduces a separate
stage for that.

In theory this series is 3 parts:
- sbi cache-flush / null-ptr
- alternatives improvements
- svpbmt+d1

So expecially patches from the first 2 areas could be applied when
deemed ready, I just thought to keep it together to show-case where
the end-goal is and not requiring jumping between different series.

I picked the recipient list from the previous versions, hopefully
I didn't forget anybody.

changes in v7:
- fix typo in patch1 (Atish)
- moved to Atish's isa-extension framework
- and therefore move regular boot-alternatives directly behind fill_hwcaps
- change T-Head errata Kconfig text (Atish)

changes in v6:
- rebase onto 5.17-rc1
- handle sbi null-ptr differently
- improve commit messages
- use riscv,mmu as property name

changes in v5:
- move to use alternatives for runtime-patching
- add D1 variant

[0] https://lore.kernel.org/r/20220222204811.2281949-2-atishp@rivosinc.com

Heiko Stuebner (12):
riscv: prevent null-pointer dereference with sbi_remote_fence_i
riscv: integrate alternatives better into the main architecture
riscv: allow different stages with alternatives
riscv: implement module alternatives
riscv: implement ALTERNATIVE_2 macro
riscv: extend concatenated alternatives-lines to the same length
riscv: prevent compressed instructions in alternatives
riscv: move boot alternatives to after fill_hwcap
riscv: Fix accessing pfn bits in PTEs for non-32bit variants
riscv: add cpufeature handling via alternatives
riscv: remove FIXMAP_PAGE_IO and fall back to its default value
riscv: add memory-type errata for T-Head

Wei Fu (1):
riscv: add RISC-V Svpbmt extension support

arch/riscv/Kconfig.erratas | 29 +++--
arch/riscv/Kconfig.socs | 1 -
arch/riscv/Makefile | 2 +-
arch/riscv/errata/Makefile | 2 +-
arch/riscv/errata/sifive/errata.c | 17 ++-
arch/riscv/errata/thead/Makefile | 1 +
arch/riscv/errata/thead/errata.c | 85 +++++++++++++++
arch/riscv/include/asm/alternative-macros.h | 114 +++++++++++---------
arch/riscv/include/asm/alternative.h | 16 ++-
arch/riscv/include/asm/errata_list.h | 52 +++++++++
arch/riscv/include/asm/fixmap.h | 2 -
arch/riscv/include/asm/hwcap.h | 1 +
arch/riscv/include/asm/pgtable-32.h | 17 +++
arch/riscv/include/asm/pgtable-64.h | 79 +++++++++++++-
arch/riscv/include/asm/pgtable-bits.h | 10 --
arch/riscv/include/asm/pgtable.h | 53 +++++++--
arch/riscv/include/asm/vendorid_list.h | 1 +
arch/riscv/kernel/Makefile | 1 +
arch/riscv/{errata => kernel}/alternative.c | 48 +++++++--
arch/riscv/kernel/cpu.c | 1 +
arch/riscv/kernel/cpufeature.c | 80 +++++++++++++-
arch/riscv/kernel/module.c | 29 +++++
arch/riscv/kernel/sbi.c | 10 +-
arch/riscv/kernel/setup.c | 2 +
arch/riscv/kernel/smpboot.c | 4 -
arch/riscv/kernel/traps.c | 2 +-
arch/riscv/mm/init.c | 1 +
27 files changed, 546 insertions(+), 114 deletions(-)
create mode 100644 arch/riscv/errata/thead/Makefile
create mode 100644 arch/riscv/errata/thead/errata.c
rename arch/riscv/{errata => kernel}/alternative.c (59%)

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2.30.2