[PATCH v4 2/4] LoongArch: Add SCQ support detection

[George Guo <dongtai.guo@linux.dev>]

From: george <guodongtai@kylinos.cn>

Check CPUCFG2_SCQ bit to determin if the CPU supports
SCQ instrction.

Co-developed-by: Yangyang Lian <lianyangyang@kylinos.cn>
Signed-off-by: Yangyang Lian <lianyangyang@kylinos.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
---
 arch/loongarch/include/asm/cpu-features.h | 1 +
 arch/loongarch/include/asm/cpu.h          | 2 ++
 arch/loongarch/include/asm/loongarch.h    | 1 +
 arch/loongarch/kernel/cpu-probe.c         | 4 ++++
 4 files changed, 8 insertions(+)

diff --git a/arch/loongarch/include/asm/cpu-features.h b/arch/loongarch/include/asm/cpu-features.h
index bd5f0457ad21d89ab902fb1971cc8b41b1d340ad..860cb58a92ba0c0316a8009d97441043374e7f10 100644
--- a/arch/loongarch/include/asm/cpu-features.h
+++ b/arch/loongarch/include/asm/cpu-features.h
@@ -70,5 +70,6 @@
 #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 f3efb00b61414a9b111ade9fe9beb410b927d937..5531039027ec763f21c7a6a88685ec81fa61d3cc 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/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h
index 3de03cb864b248cd0fb5de9ec5a86b1436ccbdef..be04b3e6f5b0cd6c5d561efcfd99502bc24e5eee 100644
--- a/arch/loongarch/include/asm/loongarch.h
+++ b/arch/loongarch/include/asm/loongarch.h
@@ -94,6 +94,7 @@
 #define  CPUCFG2_LSPW			BIT(21)
 #define  CPUCFG2_LAM			BIT(22)
 #define  CPUCFG2_PTW			BIT(24)
+#define  CPUCFG2_SCQ			BIT(30)
 
 #define LOONGARCH_CPUCFG3		0x3
 #define  CPUCFG3_CCDMA			BIT(0)
diff --git a/arch/loongarch/kernel/cpu-probe.c b/arch/loongarch/kernel/cpu-probe.c
index a2060a24b39fd78fa255816fa5518e0ee99b8a8e..47815a55b7b48bbffd4954a9b8bdf7021d7e234d 100644
--- a/arch/loongarch/kernel/cpu-probe.c
+++ b/arch/loongarch/kernel/cpu-probe.c
@@ -201,6 +201,10 @@ 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;
+	else
+		pr_warn_once("CPU does NOT support SCQ\n");
 	if (config & CPUCFG2_LSPW) {
 		c->options |= LOONGARCH_CPU_LSPW;
 		elf_hwcap |= HWCAP_LOONGARCH_LSPW;

-- 
2.49.0