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| author |  Palmer Dabbelt <palmer@rivosinc.com>
| 2023-03-29 11:56:08 -0700 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com>
| 2023-03-29 12:26:38 -0700 |
| commit | be693ef2a4aeac0d65d83a22d5fb6941f164a675 (patch) | |
| tree | cb20237b54c36f5bd19688e31d30440b8eba3a2d /arch/riscv/Kconfig.errata | |
| parent | Merge patch series "Add RISC-V 32 NOMMU support" (diff) | |
| parent | RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels (diff) | |
| download | linux-be693ef2a4aeac0d65d83a22d5fb6941f164a675.tar.gz linux-be693ef2a4aeac0d65d83a22d5fb6941f164a675.tar.bz2 linux-be693ef2a4aeac0d65d83a22d5fb6941f164a675.zip | |
Merge patch series "RISC-V: Fixes for riscv_has_extension[un]likely()'s alternative dependency"
Conor Dooley <conor.dooley@microchip.com> says:
Here's my attempt at fixing both the use of an FPU on XIP kernels and
the issue that Jason ran into where CONFIG_FPU, which needs the
alternatives frame work for has_fpu() checks, could be enabled without
the alternatives actually being present.
For the former, a "slow" fallback that does not use alternatives is
added to riscv_has_extension_[un]likely() that can be used with XIP.
Obviously, we want to make use of Jisheng's alternatives based approach
where possible, so any users of riscv_has_extension_[un]likely() will
want to make sure that they select RISCV_ALTERNATIVE.
If they don't however, they'll hit the fallback path which (should,
sparing a silly mistake from me!) behave in the same way, thus
succeeding silently. Sounds like a
To prevent "depends on !XIP_KERNEL; select RISCV_ALTERNATIVE" spreading
like the plague through the various places that want to check for the
presence of extensions, and sidestep the potential silent "success"
mentioned above, all users RISCV_ALTERNATIVE are converted from selects
to dependencies, with the option being selected for all !XIP_KERNEL
builds.
I know that the VDSO was a key place that Jisheng wanted to use the new
helper rather than static branches, and I think the fallback path
should not cause issues there.
See the thread at [1] for the prior discussion.
1 - https://lore.kernel.org/linux-riscv/20230128172856.3814-1-jszhang@kernel.org/T/#m21390d570997145d31dd8bb95002fd61f99c6573
[Palmer: these were also merged into fixes, but there's a cleanup that
depends on the merge so I'm taking it into for-next as well.]
* b4-shazam-merge:
RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels
RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()
Link: https://lore.kernel.org/r/20230324100538.3514663-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* commit '1ee7fc3f4d0a93831a20d5566f203d5ad6d44de8':
RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels
RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()
Diffstat (limited to 'arch/riscv/Kconfig.errata')
| -rw-r--r-- | arch/riscv/Kconfig.errata | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/riscv/Kconfig.errata b/arch/riscv/Kconfig.errata index 69621ae6d647..0c8f4652cd82 100644 --- a/arch/riscv/Kconfig.errata +++ b/arch/riscv/Kconfig.errata @@ -2,8 +2,7 @@ menu "CPU errata selection" config ERRATA_SIFIVE bool "SiFive errata" - depends on !XIP_KERNEL - select RISCV_ALTERNATIVE + depends on RISCV_ALTERNATIVE help All SiFive errata Kconfig depend on this Kconfig. Disabling this Kconfig will disable all SiFive errata. Please say "Y" @@ -35,8 +34,7 @@ config ERRATA_SIFIVE_CIP_1200 config ERRATA_THEAD bool "T-HEAD errata" - depends on !XIP_KERNEL - select RISCV_ALTERNATIVE + depends on RISCV_ALTERNATIVE help All T-HEAD errata Kconfig depend on this Kconfig. Disabling this Kconfig will disable all T-HEAD errata. Please say "Y" |