[PATCH 4/4] riscv: KVM: Apply insn-def to hlv encodings

Andrew Jones ajones at ventanamicro.com
Fri Aug 19 07:02:50 PDT 2022


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 at ventanamicro.com>
---
 arch/riscv/include/asm/insn-def.h | 14 ++++++++++++++
 arch/riscv/kvm/vcpu_exit.c        | 29 +++++------------------------
 2 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/arch/riscv/include/asm/insn-def.h b/arch/riscv/include/asm/insn-def.h
index cd1c0d365f47..c66d5745c5b4 100644
--- a/arch/riscv/include/asm/insn-def.h
+++ b/arch/riscv/include/asm/insn-def.h
@@ -87,4 +87,18 @@
 #define HFENCE_GVMA(gaddr, vmid)	\
 	INSN_R(OPCODE_SYSTEM, FUNC3(0), FUNC7(49), RD(0), gaddr, vmid)
 
+#define HLVX_HU(dest, addr)	\
+	INSN_R(OPCODE_SYSTEM, FUNC3(4), FUNC7(50), dest, addr, RS2(3))
+
+#define HLV_W(dest, addr)	\
+	INSN_R(OPCODE_SYSTEM, FUNC3(4), FUNC7(52), dest, addr, RS2(0))
+
+#ifdef CONFIG_64BIT
+#define HLV_D(dest, addr)	\
+	INSN_R(OPCODE_SYSTEM, FUNC3(4), FUNC7(54), dest, 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..9cb075e72799 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),
-- 
2.37.1




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