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Diffstat (limited to 'arch/loongarch/vdso/vgetcpu.c')
-rw-r--r--arch/loongarch/vdso/vgetcpu.c45
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 0000000000..9e445be397
--- /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;
+}