On 19/04/2024 17:51, Conor Dooley wrote: > On Thu, Apr 18, 2024 at 02:42:27PM +0200, Clément Léger wrote: >> The Zc* standard extension for code reduction introduces new extensions. >> This patch adds support for Zca, Zcf, Zcd and Zcb. Zce, Zcmt and Zcmp >> are left out of this patch since they are targeting microcontrollers/ >> embedded CPUs instead of application processors. >> >> Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx> >> --- >> arch/riscv/include/asm/hwcap.h | 4 ++++ >> arch/riscv/kernel/cpufeature.c | 4 ++++ >> 2 files changed, 8 insertions(+) >> >> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h >> index 543e3ea2da0e..b7551bad341b 100644 >> --- a/arch/riscv/include/asm/hwcap.h >> +++ b/arch/riscv/include/asm/hwcap.h >> @@ -82,6 +82,10 @@ >> #define RISCV_ISA_EXT_ZACAS 73 >> #define RISCV_ISA_EXT_XANDESPMU 74 >> #define RISCV_ISA_EXT_ZIMOP 75 >> +#define RISCV_ISA_EXT_ZCA 76 >> +#define RISCV_ISA_EXT_ZCB 77 >> +#define RISCV_ISA_EXT_ZCD 78 >> +#define RISCV_ISA_EXT_ZCF 79 >> >> #define RISCV_ISA_EXT_XLINUXENVCFG 127 >> >> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c >> index 115ba001f1bc..09dee071274d 100644 >> --- a/arch/riscv/kernel/cpufeature.c >> +++ b/arch/riscv/kernel/cpufeature.c >> @@ -261,6 +261,10 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = { >> __RISCV_ISA_EXT_DATA(zfa, RISCV_ISA_EXT_ZFA), >> __RISCV_ISA_EXT_DATA(zfh, RISCV_ISA_EXT_ZFH), >> __RISCV_ISA_EXT_DATA(zfhmin, RISCV_ISA_EXT_ZFHMIN), >> + __RISCV_ISA_EXT_DATA(zca, RISCV_ISA_EXT_ZCA), >> + __RISCV_ISA_EXT_DATA(zcb, RISCV_ISA_EXT_ZCB), >> + __RISCV_ISA_EXT_DATA(zcd, RISCV_ISA_EXT_ZCD), >> + __RISCV_ISA_EXT_DATA(zcf, RISCV_ISA_EXT_ZCF), >> __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA), >> __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB), >> __RISCV_ISA_EXT_DATA(zbc, RISCV_ISA_EXT_ZBC), > > Ye, this looks exactly like what I "feared". Ok but for instance, Qemu actually set Zc* based on C/F/D. So the ISA string containing theses dependencies should actually also be allowed. So should we simply ignore them in the ISA string and always do our own "post-processing" based on C/F/D ? Thanks, Clément