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[59.124.168.89]) by smtp.gmail.com with ESMTPSA id d9-20020a170902854900b0019f53e0f136sm12503965plo.232.2023.03.23.07.59.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Mar 2023 07:59:54 -0700 (PDT) From: Andy Chiu To: linux-riscv@lists.infradead.org, palmer@dabbelt.com, anup@brainfault.org, atishp@atishpatra.org, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org Cc: vineetg@rivosinc.com, greentime.hu@sifive.com, guoren@linux.alibaba.com, Andy Chiu , Paul Walmsley , Albert Ou , Vincent Chen , Conor Dooley , Guo Ren , Masahiro Yamada , Alexandre Ghiti Subject: [PATCH -next v16 04/20] riscv: Clear vector regfile on bootup Date: Thu, 23 Mar 2023 14:59:08 +0000 Message-Id: <20230323145924.4194-5-andy.chiu@sifive.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230323145924.4194-1-andy.chiu@sifive.com> References: <20230323145924.4194-1-andy.chiu@sifive.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Greentime Hu clear vector registers on boot if kernel supports V. Signed-off-by: Greentime Hu Signed-off-by: Vineet Gupta Signed-off-by: Andy Chiu Acked-by: Conor Dooley --- arch/riscv/kernel/head.S | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 4bf6c449d78b..3fd6a4bd9c3e 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -392,7 +392,7 @@ ENTRY(reset_regs) #ifdef CONFIG_FPU csrr t0, CSR_MISA andi t0, t0, (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D) - beqz t0, .Lreset_regs_done + beqz t0, .Lreset_regs_done_fpu li t1, SR_FS csrs CSR_STATUS, t1 @@ -430,8 +430,31 @@ ENTRY(reset_regs) fmv.s.x f31, zero csrw fcsr, 0 /* note that the caller must clear SR_FS */ +.Lreset_regs_done_fpu: #endif /* CONFIG_FPU */ -.Lreset_regs_done: + +#ifdef CONFIG_RISCV_ISA_V + csrr t0, CSR_MISA + li t1, COMPAT_HWCAP_ISA_V + and t0, t0, t1 + beqz t0, .Lreset_regs_done_vector + + /* + * Clear vector registers and reset vcsr + * VLMAX has a defined value, VLEN is a constant, + * and this form of vsetvli is defined to set vl to VLMAX. + */ + li t1, SR_VS + csrs CSR_STATUS, t1 + csrs CSR_VCSR, x0 + vsetvli t1, x0, e8, m8, ta, ma + vmv.v.i v0, 0 + vmv.v.i v8, 0 + vmv.v.i v16, 0 + vmv.v.i v24, 0 + /* note that the caller must clear SR_VS */ +.Lreset_regs_done_vector: +#endif /* CONFIG_RISCV_ISA_V */ ret END(reset_regs) #endif /* CONFIG_RISCV_M_MODE */