From: Palmer Dabbelt Date: Wed, 29 Mar 2023 18:56:08 +0000 (-0700) Subject: Merge patch series "RISC-V: Fixes for riscv_has_extension[un]likely()'s alternative... X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=be693ef2a4aeac0d65d83a22d5fb6941f164a675;p=linux.git Merge patch series "RISC-V: Fixes for riscv_has_extension[un]likely()'s alternative dependency" Conor Dooley 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 * commit '1ee7fc3f4d0a93831a20d5566f203d5ad6d44de8': RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely() --- be693ef2a4aeac0d65d83a22d5fb6941f164a675 diff --cc arch/riscv/Kconfig.errata index 69621ae6d647a,0000000000000..0c8f4652cd828 mode 100644,000000..100644 --- a/arch/riscv/Kconfig.errata +++ b/arch/riscv/Kconfig.errata @@@ -1,82 -1,0 +1,80 @@@ +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" + here if your platform uses SiFive CPU cores. + + Otherwise, please say "N" here to avoid unnecessary overhead. + +config ERRATA_SIFIVE_CIP_453 + bool "Apply SiFive errata CIP-453" + depends on ERRATA_SIFIVE && 64BIT + default y + help + This will apply the SiFive CIP-453 errata to add sign extension + to the $badaddr when exception type is instruction page fault + and instruction access fault. + + If you don't know what to do here, say "Y". + +config ERRATA_SIFIVE_CIP_1200 + bool "Apply SiFive errata CIP-1200" + depends on ERRATA_SIFIVE && 64BIT + default y + help + This will apply the SiFive CIP-1200 errata to repalce all + "sfence.vma addr" with "sfence.vma" to ensure that the addr + has been flushed from TLB. + + If you don't know what to do here, say "Y". + +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" + here if your platform uses T-HEAD CPU cores. + + Otherwise, please say "N" here to avoid unnecessary overhead. + +config ERRATA_THEAD_PBMT + bool "Apply T-Head memory type errata" + depends on ERRATA_THEAD && 64BIT && MMU + select RISCV_ALTERNATIVE_EARLY + default y + help + This will apply the memory type errata to handle the non-standard + memory type bits in page-table-entries on T-Head SoCs. + + If you don't know what to do here, say "Y". + +config ERRATA_THEAD_CMO + bool "Apply T-Head cache management errata" + depends on ERRATA_THEAD && MMU + select RISCV_DMA_NONCOHERENT + default y + help + This will apply the cache management errata to handle the + non-standard handling on non-coherent operations on T-Head SoCs. + + If you don't know what to do here, say "Y". + +config ERRATA_THEAD_PMU + bool "Apply T-Head PMU errata" + depends on ERRATA_THEAD && RISCV_PMU_SBI + default y + help + The T-Head C9xx cores implement a PMU overflow extension very + similar to the core SSCOFPMF extension. + + This will apply the overflow errata to handle the non-standard + behaviour via the regular SBI PMU driver and interface. + + If you don't know what to do here, say "Y". + +endmenu # "CPU errata selection"