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From:   Andrew Jones <ajones@ventanamicro.com>
To:     linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, paul.walmsley@sifive.com,
        palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org,
        mchitale@ventanamicro.com, heiko@sntech.de
Subject: [PATCH v2 4/4] riscv: KVM: Apply insn-def to hlv encodings
Date:   Wed, 31 Aug 2022 19:25:00 +0200
Message-Id: <20220831172500.752195-5-ajones@ventanamicro.com>
In-Reply-To: <20220831172500.752195-1-ajones@ventanamicro.com>
References: <20220831172500.752195-1-ajones@ventanamicro.com>
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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>
---
 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