Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/arch/loongarch/vdso/vgetcpu.c b/arch/loongarch/vdso/vgetcpu.c
new file mode 100644
index 000000000..9e445be39
--- /dev/null
+++ b/arch/loongarch/vdso/vgetcpu.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Fast user context implementation of getcpu()
+ */
+
+#include <asm/vdso.h>
+#include <linux/getcpu.h>
+
+static __always_inline int read_cpu_id(void)
+{
+	int cpu_id;
+
+	__asm__ __volatile__(
+	"	rdtime.d $zero, %0\n"
+	: "=r" (cpu_id)
+	:
+	: "memory");
+
+	return cpu_id;
+}
+
+static __always_inline const struct vdso_pcpu_data *get_pcpu_data(void)
+{
+	return (struct vdso_pcpu_data *)(get_vdso_data() + VVAR_LOONGARCH_PAGES_START * PAGE_SIZE);
+}
+
+extern
+int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused);
+int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused)
+{
+	int cpu_id;
+	const struct vdso_pcpu_data *data;
+
+	cpu_id = read_cpu_id();
+
+	if (cpu)
+		*cpu = cpu_id;
+
+	if (node) {
+		data = get_pcpu_data();
+		*node = data[cpu_id].node;
+	}
+
+	return 0;
+}