Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/csky/kernel/cpu-probe.c b/arch/csky/kernel/cpu-probe.c
new file mode 100644
index 0000000..5f15ca3
--- /dev/null
+++ b/arch/csky/kernel/cpu-probe.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/of.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/memblock.h>
+
+#include <abi/reg_ops.h>
+
+static void percpu_print(void *arg)
+{
+ struct seq_file *m = (struct seq_file *)arg;
+ unsigned int cur, next, i;
+
+ seq_printf(m, "processor : %d\n", smp_processor_id());
+ seq_printf(m, "C-SKY CPU model : %s\n", CSKYCPU_DEF_NAME);
+
+ /* read processor id, max is 100 */
+ cur = mfcr("cr13");
+ for (i = 0; i < 100; i++) {
+ seq_printf(m, "product info[%d] : 0x%08x\n", i, cur);
+
+ next = mfcr("cr13");
+
+ /* some CPU only has one id reg */
+ if (cur == next)
+ break;
+
+ cur = next;
+
+ /* cpid index is 31-28, reset */
+ if (!(next >> 28)) {
+ while ((mfcr("cr13") >> 28) != i);
+ break;
+ }
+ }
+
+ /* CPU feature regs, setup by bootloader or gdbinit */
+ seq_printf(m, "hint (CPU funcs): 0x%08x\n", mfcr_hint());
+ seq_printf(m, "ccr (L1C & MMU): 0x%08x\n", mfcr("cr18"));
+ seq_printf(m, "ccr2 (L2C) : 0x%08x\n", mfcr_ccr2());
+ seq_printf(m, "\n");
+}
+
+static int c_show(struct seq_file *m, void *v)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ smp_call_function_single(cpu, percpu_print, m, true);
+
+#ifdef CSKY_ARCH_VERSION
+ seq_printf(m, "arch-version : %s\n", CSKY_ARCH_VERSION);
+ seq_printf(m, "\n");
+#endif
+
+ return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+ return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ ++*pos;
+ return NULL;
+}
+
+static void c_stop(struct seq_file *m, void *v) {}
+
+const struct seq_operations cpuinfo_op = {
+ .start = c_start,
+ .next = c_next,
+ .stop = c_stop,
+ .show = c_show,
+};