diff options
| author | Palmer Dabbelt | 2023-03-29 11:56:08 -0700 |
|---|---|---|
| committer | Palmer Dabbelt | 2023-03-29 12:26:38 -0700 |
| commit | be693ef2a4aeac0d65d83a22d5fb6941f164a675 (patch) | |
| tree | cb20237b54c36f5bd19688e31d30440b8eba3a2d /arch/riscv/Kconfig | |
| parent | e97be4fbc1b16f3e02ee004c12967e360cb06d52 (diff) | |
| parent | 1ee7fc3f4d0a93831a20d5566f203d5ad6d44de8 (diff) | |
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')
| -rw-r--r-- | arch/riscv/Kconfig | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index d7c467670be8..b47c08364dc3 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -127,6 +127,7 @@ config RISCV select OF_IRQ select PCI_DOMAINS_GENERIC if PCI select PCI_MSI if PCI + select RISCV_ALTERNATIVE if !XIP_KERNEL select RISCV_INTC select RISCV_TIMER if RISCV_SBI select SIFIVE_PLIC @@ -420,9 +421,8 @@ config RISCV_ISA_SVNAPOT config RISCV_ISA_SVPBMT bool "SVPBMT extension support" depends on 64BIT && MMU - depends on !XIP_KERNEL + depends on RISCV_ALTERNATIVE default y - select RISCV_ALTERNATIVE help Adds support to dynamically detect the presence of the SVPBMT ISA-extension (Supervisor-mode: page-based memory types) and @@ -447,8 +447,8 @@ config TOOLCHAIN_HAS_ZBB config RISCV_ISA_ZBB bool "Zbb extension support for bit manipulation instructions" depends on TOOLCHAIN_HAS_ZBB - depends on !XIP_KERNEL && MMU - select RISCV_ALTERNATIVE + depends on MMU + depends on RISCV_ALTERNATIVE default y help Adds support to dynamically detect the presence of the ZBB @@ -462,9 +462,9 @@ config RISCV_ISA_ZBB config RISCV_ISA_ZICBOM bool "Zicbom extension support for non-coherent DMA operation" - depends on !XIP_KERNEL && MMU + depends on MMU + depends on RISCV_ALTERNATIVE default y - select RISCV_ALTERNATIVE select RISCV_DMA_NONCOHERENT help Adds support to dynamically detect the presence of the ZICBOM |