On Tue, 30 Jul 2019, Atish Patra wrote:
> From: Anup Patel <anup.patel@xxxxxxx>
>
> This patch adds riscv_isa integer to represent ISA features common
> across all CPUs. The riscv_isa is not same as elf_hwcap because
> elf_hwcap will only have ISA features relevant for user-space apps
> whereas riscv_isa will have ISA features relevant to both kernel
> and user-space apps.
>
> One of the use case is KVM hypervisor where riscv_isa will be used
> to do following operations:
>
> 1. Check whether hypervisor extension is available
> 2. Find ISA features that need to be virtualized (e.g. floating
> point support, vector extension, etc.)
>
> Signed-off-by: Anup Patel <anup.patel@xxxxxxx>
> Signed-off-by: Atish Patra <atish.patra@xxxxxxx>
> ---
> arch/riscv/include/asm/hwcap.h | 25 +++++++++++++++++++++
> arch/riscv/kernel/cpufeature.c | 41 +++++++++++++++++++++++++++++++---
> 2 files changed, 63 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index 7ecb7c6a57b1..e069f60ad5d2 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -22,5 +22,30 @@ enum {
> };
>
> extern unsigned long elf_hwcap;
> +
> +#define RISCV_ISA_EXT_A (1UL << ('A' - 'A'))
Are these uppercase variants still needed if we define the ISA string to
be all lowercase, per our recent discussion?
> +#define RISCV_ISA_EXT_a RISCV_ISA_EXT_A
> +#define RISCV_ISA_EXT_C (1UL << ('C' - 'A'))
> +#define RISCV_ISA_EXT_c RISCV_ISA_EXT_C
> +#define RISCV_ISA_EXT_D (1UL << ('D' - 'A'))
> +#define RISCV_ISA_EXT_d RISCV_ISA_EXT_D
> +#define RISCV_ISA_EXT_F (1UL << ('F' - 'A'))
> +#define RISCV_ISA_EXT_f RISCV_ISA_EXT_F
> +#define RISCV_ISA_EXT_H (1UL << ('H' - 'A'))
> +#define RISCV_ISA_EXT_h RISCV_ISA_EXT_H
> +#define RISCV_ISA_EXT_I (1UL << ('I' - 'A'))
> +#define RISCV_ISA_EXT_i RISCV_ISA_EXT_I
> +#define RISCV_ISA_EXT_M (1UL << ('M' - 'A'))
> +#define RISCV_ISA_EXT_m RISCV_ISA_EXT_M
> +#define RISCV_ISA_EXT_S (1UL << ('S' - 'A'))
> +#define RISCV_ISA_EXT_s RISCV_ISA_EXT_S
> +#define RISCV_ISA_EXT_U (1UL << ('U' - 'A'))
> +#define RISCV_ISA_EXT_u RISCV_ISA_EXT_U
> +
> +extern unsigned long riscv_isa;
> +
> +#define riscv_isa_extension_available(ext_char) \
> + (riscv_isa & RISCV_ISA_EXT_##ext_char)
> +
> #endif
> #endif
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index b1ade9a49347..177529d48d87 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
[ ... ]
> @@ -43,8 +49,22 @@ void riscv_fill_hwcap(void)
> continue;
> }
>
> - for (i = 0; i < strlen(isa); ++i)
> + i = 0;
> + isa_len = strlen(isa);
> +#if defined(CONFIG_32BIT)
> + if (strncasecmp(isa, "rv32", 4) != 0)
strcmp()?
> + i += 4;
> +#elif defined(CONFIG_64BIT)
> + if (strncasecmp(isa, "rv64", 4) != 0)
And again here?
> + i += 4;
> +#endif
> + for (; i < isa_len; ++i) {
> this_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
> + if ('a' <= isa[i] && isa[i] <= 'z')
> + this_isa |= (1UL << (isa[i] - 'a'));
> + if ('A' <= isa[i] && isa[i] <= 'Z')
> + this_isa |= (1UL << (isa[i] - 'A'));
Are these uppercase variants still needed?
- Paul
