[PATCH 5/5] x86_64, -march=native: MOVBE support

[Alexey Dobriyan]

Use MOVBE if it is available.

Internally MOVBE probably translates to MOV+BSWAP anyway, but who knows.

Do it because it is easy to do...

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
 arch/x86/crypto/des3_ede-asm_64.S | 28 ++++++++++++++++++++++++++++
 arch/x86/kernel/verify_cpu.S      |  7 +++++++
 scripts/kconfig/cpuid.c           |  5 +++++
 scripts/march-native.sh           |  1 +
 4 files changed, 41 insertions(+)

diff --git a/arch/x86/crypto/des3_ede-asm_64.S b/arch/x86/crypto/des3_ede-asm_64.S
index 7fca43099a5f..2fd310e98b0b 100644
--- a/arch/x86/crypto/des3_ede-asm_64.S
+++ b/arch/x86/crypto/des3_ede-asm_64.S
@@ -150,6 +150,15 @@
 
 #define dummy2(a, b) /*_*/
 
+#ifdef CONFIG_MARCH_NATIVE_MOVBE
+#define read_block(io, left, right) \
+	movbe	 (io), left##d; \
+	movbe	4(io), right##d;
+
+#define write_block(io, left, right) \
+	movbe	left##d,   (io); \
+	movbe	right##d, 4(io);
+#else
 #define read_block(io, left, right) \
 	movl    (io), left##d; \
 	movl   4(io), right##d; \
@@ -161,6 +170,7 @@
 	bswapl right##d; \
 	movl   left##d,   (io); \
 	movl   right##d, 4(io);
+#endif
 
 ENTRY(des3_ede_x86_64_crypt_blk)
 	/* input:
@@ -434,6 +444,14 @@ ENTRY(des3_ede_x86_64_crypt_blk_3way)
 	pushq %rsi /* dst */
 
 	/* load input */
+#ifdef CONFIG_MARCH_NATIVE_MOVBE
+	movbe 0 * 4(%rdx), RL0d;
+	movbe 1 * 4(%rdx), RR0d;
+	movbe 2 * 4(%rdx), RL1d;
+	movbe 3 * 4(%rdx), RR1d;
+	movbe 4 * 4(%rdx), RL2d;
+	movbe 5 * 4(%rdx), RR2d;
+#else
 	movl 0 * 4(%rdx), RL0d;
 	movl 1 * 4(%rdx), RR0d;
 	movl 2 * 4(%rdx), RL1d;
@@ -447,6 +465,7 @@ ENTRY(des3_ede_x86_64_crypt_blk_3way)
 	bswapl RR1d;
 	bswapl RL2d;
 	bswapl RR2d;
+#endif
 
 	initial_permutation3(RL, RR);
 
@@ -507,6 +526,14 @@ ENTRY(des3_ede_x86_64_crypt_blk_3way)
 
 	final_permutation3(RR, RL);
 
+#ifdef CONFIG_MARCH_NATIVE_MOVBE
+	movbe RR0d, 0 * 4(%rsi);
+	movbe RL0d, 1 * 4(%rsi);
+	movbe RR1d, 2 * 4(%rsi);
+	movbe RL1d, 3 * 4(%rsi);
+	movbe RR2d, 4 * 4(%rsi);
+	movbe RL2d, 5 * 4(%rsi);
+#else
 	bswapl RR0d;
 	bswapl RL0d;
 	bswapl RR1d;
@@ -521,6 +548,7 @@ ENTRY(des3_ede_x86_64_crypt_blk_3way)
 	movl RL1d, 3 * 4(%rsi);
 	movl RR2d, 4 * 4(%rsi);
 	movl RL2d, 5 * 4(%rsi);
+#endif
 
 	popq %r15;
 	popq %r14;
diff --git a/arch/x86/kernel/verify_cpu.S b/arch/x86/kernel/verify_cpu.S
index d3f3370e7dab..f8ff130edfb3 100644
--- a/arch/x86/kernel/verify_cpu.S
+++ b/arch/x86/kernel/verify_cpu.S
@@ -142,6 +142,13 @@ ENTRY(verify_cpu)
 	jnc	.Lverify_cpu_no_longmode
 #endif
 
+#ifdef CONFIG_MARCH_NATIVE_MOVBE
+	mov	$1, %eax
+	cpuid
+	bt	$22, %ecx
+	jnc	.Lverify_cpu_no_longmode
+#endif
+
 #if defined(CONFIG_MARCH_NATIVE_REP_MOVSB) || defined(CONFIG_MARCH_NATIVE_REP_STOSB)
 	xor	%eax, %eax
 	cpuid
diff --git a/scripts/kconfig/cpuid.c b/scripts/kconfig/cpuid.c
index 58d09bda61e5..0da1142a59da 100644
--- a/scripts/kconfig/cpuid.c
+++ b/scripts/kconfig/cpuid.c
@@ -43,6 +43,7 @@ static inline void cpuid2(uint32_t eax0, uint32_t ecx0, uint32_t *eax, uint32_t
 	);
 }
 
+static bool movbe	= false;
 static bool popcnt	= false;
 static bool rep_movsb	= false;
 static bool rep_stosb	= false;
@@ -57,6 +58,9 @@ static void intel(void)
 		cpuid(1, &eax, &ecx, &edx, &ebx);
 //		printf("%08x %08x %08x %08x\n", eax, ecx, edx, ebx);
 
+		if (ecx & (1 << 22)) {
+			movbe = true;
+		}
 		if (ecx & (1 << 23)) {
 			popcnt = true;
 		}
@@ -89,6 +93,7 @@ int main(int argc, char *argv[])
 	}
 
 #define _(x)	if (streq(opt, #x)) return x ? EXIT_SUCCESS : EXIT_FAILURE
+	_(movbe);
 	_(popcnt);
 	_(rep_movsb);
 	_(rep_stosb);
diff --git a/scripts/march-native.sh b/scripts/march-native.sh
index a41a15a64df4..530bac22fa07 100755
--- a/scripts/march-native.sh
+++ b/scripts/march-native.sh
@@ -41,6 +41,7 @@ COLLECT_GCC_OPTIONS=$(
 )
 echo "-march=native: $COLLECT_GCC_OPTIONS"
 
+"$CPUID" movbe		&& option "CONFIG_MARCH_NATIVE_MOVBE"
 "$CPUID" popcnt		&& option "CONFIG_MARCH_NATIVE_POPCNT"
 "$CPUID" rep_movsb	&& option "CONFIG_MARCH_NATIVE_REP_MOVSB"
 "$CPUID" rep_stosb	&& option "CONFIG_MARCH_NATIVE_REP_STOSB"
-- 
2.21.0