linux-kernel - [tip: x86/asm] x86/hyperv: Use named operands in inline asm

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Message-ID: <174108458596.14745.10846308979163517610.tip-bot2@tip-bot2>
Date: Tue, 04 Mar 2025 10:36:25 -0000
From: "tip-bot2 for Josh Poimboeuf" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Josh Poimboeuf <jpoimboe@...nel.org>, Ingo Molnar <mingo@...nel.org>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>,
 "K. Y. Srinivasan" <kys@...rosoft.com>,
 Haiyang Zhang <haiyangz@...rosoft.com>, Wei Liu <wei.liu@...nel.org>,
 Dexuan Cui <decui@...rosoft.com>, linux-kernel@...r.kernel.org,
 x86@...nel.org
Subject: [tip: x86/asm] x86/hyperv: Use named operands in inline asm

The following commit has been merged into the x86/asm branch of tip:

Commit-ID:     9064a8e556fa70ccfd9c414350406ed4887d3059
Gitweb:        https://git.kernel.org/tip/9064a8e556fa70ccfd9c414350406ed4887d3059
Author:        Josh Poimboeuf <jpoimboe@...nel.org>
AuthorDate:    Sun, 02 Mar 2025 17:21:00 -08:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Tue, 04 Mar 2025 11:21:39 +01:00

x86/hyperv: Use named operands in inline asm

Use named operands in inline asm to make it easier to change the
constraint order.

Do this in preparation of changing the ASM_CALL_CONSTRAINT primitive.

Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: "K. Y. Srinivasan" <kys@...rosoft.com>
Cc: Haiyang Zhang <haiyangz@...rosoft.com>
Cc: Wei Liu <wei.liu@...nel.org>
Cc: Dexuan Cui <decui@...rosoft.com>
Cc: linux-kernel@...r.kernel.org
---
 arch/x86/include/asm/mshyperv.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f91ab1e..5e6193d 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -77,11 +77,11 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
 		return hv_tdx_hypercall(control, input_address, output_address);
 
 	if (hv_isolation_type_snp() && !hyperv_paravisor_present) {
-		__asm__ __volatile__("mov %4, %%r8\n"
+		__asm__ __volatile__("mov %[output_address], %%r8\n"
 				     "vmmcall"
 				     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
 				       "+c" (control), "+d" (input_address)
-				     :  "r" (output_address)
+				     : [output_address] "r" (output_address)
 				     : "cc", "memory", "r8", "r9", "r10", "r11");
 		return hv_status;
 	}
@@ -89,12 +89,12 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
 	if (!hv_hypercall_pg)
 		return U64_MAX;
 
-	__asm__ __volatile__("mov %4, %%r8\n"
+	__asm__ __volatile__("mov %[output_address], %%r8\n"
 			     CALL_NOSPEC
 			     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
 			       "+c" (control), "+d" (input_address)
-			     :  "r" (output_address),
-				THUNK_TARGET(hv_hypercall_pg)
+			     : [output_address] "r" (output_address),
+			       THUNK_TARGET(hv_hypercall_pg)
 			     : "cc", "memory", "r8", "r9", "r10", "r11");
 #else
 	u32 input_address_hi = upper_32_bits(input_address);
@@ -187,18 +187,18 @@ static inline u64 _hv_do_fast_hypercall16(u64 control, u64 input1, u64 input2)
 		return hv_tdx_hypercall(control, input1, input2);
 
 	if (hv_isolation_type_snp() && !hyperv_paravisor_present) {
-		__asm__ __volatile__("mov %4, %%r8\n"
+		__asm__ __volatile__("mov %[input2], %%r8\n"
 				     "vmmcall"
 				     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
 				       "+c" (control), "+d" (input1)
-				     : "r" (input2)
+				     : [input2] "r" (input2)
 				     : "cc", "r8", "r9", "r10", "r11");
 	} else {
-		__asm__ __volatile__("mov %4, %%r8\n"
+		__asm__ __volatile__("mov %[input2], %%r8\n"
 				     CALL_NOSPEC
 				     : "=a" (hv_status), ASM_CALL_CONSTRAINT,
 				       "+c" (control), "+d" (input1)
-				     : "r" (input2),
+				     : [input2] "r" (input2),
 				       THUNK_TARGET(hv_hypercall_pg)
 				     : "cc", "r8", "r9", "r10", "r11");
 	}