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From:   Anup Patel <anup@brainfault.org>
Date:   Fri, 2 Sep 2022 12:23:27 +0530
Message-ID: <CAAhSdy1746pbZKBuFizhv6e8_ivSd4ePNkN_OG6X0NEhcrVRfw@mail.gmail.com>
Subject: Re: [PATCH v2 4/4] riscv: KVM: Apply insn-def to hlv encodings
To:     Andrew Jones <ajones@ventanamicro.com>
Cc:     linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, paul.walmsley@sifive.com,
        palmer@dabbelt.com, aou@eecs.berkeley.edu,
        mchitale@ventanamicro.com, heiko@sntech.de
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On Wed, Aug 31, 2022 at 10:55 PM Andrew Jones <ajones@ventanamicro.com> wrote:
>
> Introduce hlv instruction encodings and apply them to KVM's use.
> We're careful not to introduce hlv.d to 32-bit builds. Indeed,
> we ensure the build fails if someone tries to use it.
>
> Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
> Reviewed-by: Anup Patel <anup@brainfault.org>

I have queued this patch for Linux-6.1

Thanks,
Anup

> ---
>  arch/riscv/include/asm/insn-def.h | 17 +++++++++++++++++
>  arch/riscv/kvm/vcpu_exit.c        | 29 +++++------------------------
>  2 files changed, 22 insertions(+), 24 deletions(-)
>
> diff --git a/arch/riscv/include/asm/insn-def.h b/arch/riscv/include/asm/insn-def.h
> index 86c1f602413b..8fe9036efb68 100644
> --- a/arch/riscv/include/asm/insn-def.h
> +++ b/arch/riscv/include/asm/insn-def.h
> @@ -93,4 +93,21 @@
>         INSN_R(OPCODE_SYSTEM, FUNC3(0), FUNC7(49),              \
>                __RD(0), RS1(gaddr), RS2(vmid))
>
> +#define HLVX_HU(dest, addr)                                    \
> +       INSN_R(OPCODE_SYSTEM, FUNC3(4), FUNC7(50),              \
> +              RD(dest), RS1(addr), __RS2(3))
> +
> +#define HLV_W(dest, addr)                                      \
> +       INSN_R(OPCODE_SYSTEM, FUNC3(4), FUNC7(52),              \
> +              RD(dest), RS1(addr), __RS2(0))
> +
> +#ifdef CONFIG_64BIT
> +#define HLV_D(dest, addr)                                      \
> +       INSN_R(OPCODE_SYSTEM, FUNC3(4), FUNC7(54),              \
> +              RD(dest), RS1(addr), __RS2(0))
> +#else
> +#define HLV_D(dest, addr)      \
> +       __ASM_STR(.error "hlv.d requires 64-bit support")
> +#endif
> +
>  #endif /* __ASM_INSN_DEF_H */
> diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
> index d5c36386878a..da793f113a72 100644
> --- a/arch/riscv/kvm/vcpu_exit.c
> +++ b/arch/riscv/kvm/vcpu_exit.c
> @@ -8,6 +8,7 @@
>
>  #include <linux/kvm_host.h>
>  #include <asm/csr.h>
> +#include <asm/insn-def.h>
>
>  static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
>                              struct kvm_cpu_trap *trap)
> @@ -82,22 +83,12 @@ unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
>                         ".option push\n"
>                         ".option norvc\n"
>                         "add %[ttmp], %[taddr], 0\n"
> -                       /*
> -                        * HLVX.HU %[val], (%[addr])
> -                        * HLVX.HU t0, (t2)
> -                        * 0110010 00011 00111 100 00101 1110011
> -                        */
> -                       ".word 0x6433c2f3\n"
> +                       HLVX_HU(%[val], %[addr])
>                         "andi %[tmp], %[val], 3\n"
>                         "addi %[tmp], %[tmp], -3\n"
>                         "bne %[tmp], zero, 2f\n"
>                         "addi %[addr], %[addr], 2\n"
> -                       /*
> -                        * HLVX.HU %[tmp], (%[addr])
> -                        * HLVX.HU t1, (t2)
> -                        * 0110010 00011 00111 100 00110 1110011
> -                        */
> -                       ".word 0x6433c373\n"
> +                       HLVX_HU(%[tmp], %[addr])
>                         "sll %[tmp], %[tmp], 16\n"
>                         "add %[val], %[val], %[tmp]\n"
>                         "2:\n"
> @@ -121,19 +112,9 @@ unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
>                         ".option norvc\n"
>                         "add %[ttmp], %[taddr], 0\n"
>  #ifdef CONFIG_64BIT
> -                       /*
> -                        * HLV.D %[val], (%[addr])
> -                        * HLV.D t0, (t2)
> -                        * 0110110 00000 00111 100 00101 1110011
> -                        */
> -                       ".word 0x6c03c2f3\n"
> +                       HLV_D(%[val], %[addr])
>  #else
> -                       /*
> -                        * HLV.W %[val], (%[addr])
> -                        * HLV.W t0, (t2)
> -                        * 0110100 00000 00111 100 00101 1110011
> -                        */
> -                       ".word 0x6803c2f3\n"
> +                       HLV_W(%[val], %[addr])
>  #endif
>                         ".option pop"
>                 : [val] "=&r" (val),
> --
> 2.37.2
>