From: George Guo <dongtai.guo@linux.dev>
To: Huacai Chen <chenhuacai@kernel.org>, WANG Xuerui <kernel@xen0n.name>
Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org,
George Guo <dongtai.guo@linux.dev>,
george <guodongtai@kylinos.cn>,
Yangyang Lian <lianyangyang@kylinos.cn>,
George Guo <guodongtai@kylinos.cn>
Subject: [PATCH v4 2/4] LoongArch: Add SCQ support detection
Date: Fri, 05 Dec 2025 14:29:05 +0800 [thread overview]
Message-ID: <20251205-2-v4-2-e5ab932cf219@linux.dev> (raw)
In-Reply-To: <20251205-2-v4-0-e5ab932cf219@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
next prev parent reply other threads:[~2025-12-05 6:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-05 6:29 [PATCH v4 0/4] LoongArch: Add 128-bit atomic cmpxchg support (v4) George Guo
2025-12-05 6:29 ` [PATCH v4 1/4] LoongArch: Add 128-bit atomic cmpxchg support George Guo
2025-12-05 6:29 ` George Guo [this message]
2025-12-05 6:29 ` [PATCH v4 3/4] LoongArch: Use spinlock to emulate 128-bit cmpxchg George Guo
2025-12-05 6:29 ` [PATCH v4 4/4] LoongArch: Enable 128-bit atomics cmpxchg support George Guo
2025-12-10 4:07 ` [PATCH v4 0/4] LoongArch: Add 128-bit atomic cmpxchg support (v4) Hengqi Chen
2025-12-10 4:08 ` Hengqi Chen
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