riscv: KVM: Apply insn-def to hlv encodings

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>
Signed-off-by: Anup Patel <anup@brainfault.org>

arch/riscv/include/asm/insn-def.h

@@ -97,4 +97,21 @@
 	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 */

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)
@@ -62,11 +63,7 @@ unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
 {
 	register unsigned long taddr asm("a0") = (unsigned long)trap;
 	register unsigned long ttmp asm("a1");
-	register unsigned long val asm("t0");
-	register unsigned long tmp asm("t1");
-	register unsigned long addr asm("t2") = guest_addr;
-	unsigned long flags;
-	unsigned long old_stvec, old_hstatus;
+	unsigned long flags, val, tmp, old_stvec, old_hstatus;
 
 	local_irq_save(flags);
 
@@ -82,29 +79,19 @@ 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"
 			".option pop"
 		: [val] "=&r" (val), [tmp] "=&r" (tmp),
 		  [taddr] "+&r" (taddr), [ttmp] "+&r" (ttmp),
-		  [addr] "+&r" (addr) : : "memory");
+		  [addr] "+&r" (guest_addr) : : "memory");
 
 		if (trap->scause == EXC_LOAD_PAGE_FAULT)
 			trap->scause = EXC_INST_PAGE_FAULT;
@@ -121,24 +108,14 @@ 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),
 		  [taddr] "+&r" (taddr), [ttmp] "+&r" (ttmp)
-		: [addr] "r" (addr) : "memory");
+		: [addr] "r" (guest_addr) : "memory");
 	}
 
 	csr_write(CSR_STVEC, old_stvec);