linux-kernel - [PATCH v9 loongarch-next 2/4] LoongArch: Add SCQ support detection

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Message-ID: <20260105105514.76021-3-dongtai.guo@linux.dev>
Date: Mon,  5 Jan 2026 18:55:12 +0800
From: George Guo <dongtai.guo@...ux.dev>
To: chenhuacai@...nel.org
Cc: dongtai.guo@...ux.dev,
	hengqi.chen@...il.com,
	kernel@...0n.name,
	lianyangyang@...inos.cn,
	linux-kernel@...r.kernel.org,
	loongarch@...ts.linux.dev,
	r@....cc,
	xry111@...111.site,
	George Guo <guodongtai@...inos.cn>
Subject: [PATCH v9 loongarch-next 2/4] LoongArch: Add SCQ support detection

From: George Guo <guodongtai@...inos.cn>

Check CPUCFG2_SCQ bit to determine if the CPU supports
SCQ instruction.

Co-developed-by: Yangyang Lian <lianyangyang@...inos.cn>
Signed-off-by: Yangyang Lian <lianyangyang@...inos.cn>
Reviewed-by: Hengqi Chen <hengqi.chen@...il.com>
Tested-by: Hengqi Chen <hengqi.chen@...il.com>
Signed-off-by: George Guo <guodongtai@...inos.cn>
---
 arch/loongarch/include/asm/cpu-features.h | 1 +
 arch/loongarch/include/asm/cpu.h          | 2 ++
 arch/loongarch/include/uapi/asm/hwcap.h   | 1 +
 arch/loongarch/kernel/cpu-probe.c         | 4 ++++
 arch/loongarch/kernel/proc.c              | 2 ++
 5 files changed, 10 insertions(+)

diff --git a/arch/loongarch/include/asm/cpu-features.h b/arch/loongarch/include/asm/cpu-features.h
index 3745d991a99a..39c7fe64c3ef 100644
--- a/arch/loongarch/include/asm/cpu-features.h
+++ b/arch/loongarch/include/asm/cpu-features.h
@@ -67,5 +67,6 @@
 #define cpu_has_msgint		cpu_opt(LOONGARCH_CPU_MSGINT)
 #define cpu_has_avecint		cpu_opt(LOONGARCH_CPU_AVECINT)
 #define cpu_has_redirectint	cpu_opt(LOONGARCH_CPU_REDIRECTINT)
+#define cpu_has_scq		cpu_opt(LOONGARCH_CPU_SCQ)
 
 #endif /* __ASM_CPU_FEATURES_H */
diff --git a/arch/loongarch/include/asm/cpu.h b/arch/loongarch/include/asm/cpu.h
index f3efb00b6141..5531039027ec 100644
--- a/arch/loongarch/include/asm/cpu.h
+++ b/arch/loongarch/include/asm/cpu.h
@@ -125,6 +125,7 @@ static inline char *id_to_core_name(unsigned int id)
 #define CPU_FEATURE_MSGINT		29	/* CPU has MSG interrupt */
 #define CPU_FEATURE_AVECINT		30	/* CPU has AVEC interrupt */
 #define CPU_FEATURE_REDIRECTINT		31	/* CPU has interrupt remapping */
+#define CPU_FEATURE_SCQ			32	/* CPU has SC.Q instruction */
 
 #define LOONGARCH_CPU_CPUCFG		BIT_ULL(CPU_FEATURE_CPUCFG)
 #define LOONGARCH_CPU_LAM		BIT_ULL(CPU_FEATURE_LAM)
@@ -158,5 +159,6 @@ static inline char *id_to_core_name(unsigned int id)
 #define LOONGARCH_CPU_MSGINT		BIT_ULL(CPU_FEATURE_MSGINT)
 #define LOONGARCH_CPU_AVECINT		BIT_ULL(CPU_FEATURE_AVECINT)
 #define LOONGARCH_CPU_REDIRECTINT	BIT_ULL(CPU_FEATURE_REDIRECTINT)
+#define LOONGARCH_CPU_SCQ		BIT_ULL(CPU_FEATURE_SCQ)
 
 #endif /* _ASM_CPU_H */
diff --git a/arch/loongarch/include/uapi/asm/hwcap.h b/arch/loongarch/include/uapi/asm/hwcap.h
index 2b34e56cfa9e..a3c570d407b9 100644
--- a/arch/loongarch/include/uapi/asm/hwcap.h
+++ b/arch/loongarch/include/uapi/asm/hwcap.h
@@ -18,5 +18,6 @@
 #define HWCAP_LOONGARCH_LBT_MIPS	(1 << 12)
 #define HWCAP_LOONGARCH_PTW		(1 << 13)
 #define HWCAP_LOONGARCH_LSPW		(1 << 14)
+#define HWCAP_LOONGARCH_CPU_SCQ		(1 << 15)
 
 #endif /* _UAPI_ASM_HWCAP_H */
diff --git a/arch/loongarch/kernel/cpu-probe.c b/arch/loongarch/kernel/cpu-probe.c
index 08a227034042..0051f2fcd3ec 100644
--- a/arch/loongarch/kernel/cpu-probe.c
+++ b/arch/loongarch/kernel/cpu-probe.c
@@ -205,6 +205,10 @@ static void cpu_probe_common(struct cpuinfo_loongarch *c)
 		c->options |= LOONGARCH_CPU_PTW;
 		elf_hwcap |= HWCAP_LOONGARCH_PTW;
 	}
+	if (config & CPUCFG2_SCQ) {
+		c->options |= LOONGARCH_CPU_SCQ;
+		elf_hwcap |= HWCAP_LOONGARCH_CPU_SCQ;
+	}
 	if (config & CPUCFG2_LSPW) {
 		c->options |= LOONGARCH_CPU_LSPW;
 		elf_hwcap |= HWCAP_LOONGARCH_LSPW;
diff --git a/arch/loongarch/kernel/proc.c b/arch/loongarch/kernel/proc.c
index 1d646da010f9..1b9cc05d1f33 100644
--- a/arch/loongarch/kernel/proc.c
+++ b/arch/loongarch/kernel/proc.c
@@ -90,6 +90,8 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		seq_puts(m, " lbt_arm");
 	if (cpu_has_lbt_mips)
 		seq_puts(m, " lbt_mips");
+	if (cpu_has_scq)
+		seq_puts(m, " scq");
 	seq_puts(m, "\n");
 
 	seq_printf(m, "Hardware Watchpoint\t: %s", str_yes_no(cpu_has_watch));
-- 
2.43.0