Samuel Holland 4774848fef riscv: Add a custom ISA extension for the [ms]envcfg CSR ... The [ms]envcfg CSR was added in version 1.12 of the RISC-V privileged ISA (aka S[ms]1p12). However, bits in this CSR are defined by several other extensions which may be implemented separately from any particular version of the privileged ISA (for example, some unrelated errata may prevent an implementation from claiming conformance with Ss1p12). As a result, Linux cannot simply use the privileged ISA version to determine if the CSR is present. It must also check if any of these other extensions are implemented. It also cannot probe the existence of the CSR at runtime, because Linux does not require Sstrict, so (in the absence of additional information) it cannot know if a CSR at that address is [ms]envcfg or part of some non-conforming vendor extension. Since there are several standard extensions that imply the existence of the [ms]envcfg CSR, it becomes unwieldy to check for all of them wherever the CSR is accessed. Instead, define a custom Xlinuxenvcfg ISA extension bit that is implied by the other extensions and denotes that the CSR exists as defined in the privileged ISA, containing at least one of the fields common between menvcfg and senvcfg. This extension does not need to be parsed from the devicetree or ISA string because it can only be implemented as a subset of some other standard extension. Cc: <stable@vger.kernel.org> # v6.7+ Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240228065559.3434837-3-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>		2024-02-29 10:20:17 -08:00
..
boot	SoC: DT changes for 6.8	2024-01-11 11:23:17 -08:00
configs	Merge patch series "RISC-V SBI debug console extension support"	2024-01-11 07:36:27 -08:00
errata	Merge patch series "riscv: errata: thead: use riscv_nonstd_cache_ops for CMO"	2024-01-11 07:36:30 -08:00
include	riscv: Add a custom ISA extension for the [ms]envcfg CSR	2024-02-29 10:20:17 -08:00
kernel	riscv: Add a custom ISA extension for the [ms]envcfg CSR	2024-02-29 10:20:17 -08:00
kvm	Generic:	2024-01-17 13:03:37 -08:00
lib	riscv: lib: Check if output in asm goto supported	2024-01-18 14:41:38 -08:00
mm	RISC-V Patches for the 6.8 Merge Window, Part 4	2024-01-20 11:06:04 -08:00
net	bpf: Use arch_bpf_trampoline_size	2023-12-06 17:17:20 -08:00
purgatory	riscv: Use SYM_*() assembly macros instead of deprecated ones	2023-11-06 09:42:47 -08:00
tools	riscv: Check relocations at compile time	2023-04-19 07:46:32 -07:00
Kbuild	kexec: rename ARCH_HAS_KEXEC_PURGATORY	2023-08-18 10:18:54 -07:00
Kconfig	RISC-V Patches for the 6.8 Merge Window, Part 4	2024-01-20 11:06:04 -08:00
Kconfig.debug	riscv: Add tests for riscv module loading	2023-11-07 14:59:32 -08:00
Kconfig.errata	RISC-V Patches for the 6.8 Merge Window, Part 4	2024-01-20 11:06:04 -08:00
Kconfig.socs	SoC driver updates for 6.7	2023-11-01 14:46:51 -10:00
Makefile	riscv: add dependency among Image(.gz), loader(.bin), and vmlinuz.efi	2024-01-17 18:18:20 -08:00
Makefile.postlink	kbuild: remove ARCH_POSTLINK from module builds	2023-10-28 21:10:08 +09:00