From df513ed49f0073ce1778eb469ab5db44bceade30 Mon Sep 17 00:00:00 2001 From: Heiko Stuebner Date: Sun, 21 Jan 2024 16:19:12 -0800 Subject: [PATCH] RISC-V: add helper function to read the vector VLEN VLEN describes the length of each vector register and some instructions need specific minimal VLENs to work correctly. The vector code already includes a variable riscv_v_vsize that contains the value of "32 vector registers with vlenb length" that gets filled during boot. vlenb is the value contained in the CSR_VLENB register and the value represents "VLEN / 8". So add riscv_vector_vlen() to return the actual VLEN value for in-kernel users when they need to check the available VLEN. Signed-off-by: Heiko Stuebner Reviewed-by: Eric Biggers Signed-off-by: Jerry Shih Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20240122002024.27477-2-ebiggers@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/vector.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 0cd6f0a027d1f..731dcd0ed4de9 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -284,4 +284,15 @@ static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; } #endif /* CONFIG_RISCV_ISA_V */ +/* + * Return the implementation's vlen value. + * + * riscv_v_vsize contains the value of "32 vector registers with vlenb length" + * so rebuild the vlen value in bits from it. + */ +static inline int riscv_vector_vlen(void) +{ + return riscv_v_vsize / 32 * 8; +} + #endif /* ! __ASM_RISCV_VECTOR_H */ -- 2.30.2