[RFC PATCH v2 29/31] kvx: Add support for cpuinfo

[Yann Sionneau <ysionneau@kalray.eu>]

Add support for cpuinfo on kvx arch.

Co-developed-by: Clement Leger <clement@clement-leger.fr>
Signed-off-by: Clement Leger <clement@clement-leger.fr>
Co-developed-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
Signed-off-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
Co-developed-by: Julian Vetter <jvetter@kalray.eu>
Signed-off-by: Julian Vetter <jvetter@kalray.eu>
Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
---

Notes:
    V1 -> V2: no changes

 arch/kvx/kernel/cpuinfo.c | 96 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 arch/kvx/kernel/cpuinfo.c

diff --git a/arch/kvx/kernel/cpuinfo.c b/arch/kvx/kernel/cpuinfo.c
new file mode 100644
index 000000000000..f44c46c1e4ba
--- /dev/null
+++ b/arch/kvx/kernel/cpuinfo.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ *            Guillaume Thouvenin
+ */
+
+#include <linux/seq_file.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+
+unsigned long elf_hwcap __read_mostly;
+
+static int show_cpuinfo(struct seq_file *m, void *v)
+{
+	int cpu_num = *(unsigned int *)v;
+	struct cpuinfo_kvx *n = per_cpu_ptr(&cpu_info, cpu_num);
+
+	seq_printf(m, "processor\t: %d\nvendor_id\t: Kalray\n", cpu_num);
+
+	seq_printf(m,
+		   "copro enabled\t: %s\n"
+		   "arch revision\t: %d\n"
+		   "uarch revision\t: %d\n",
+		   n->copro_enable ? "yes" : "no",
+		   n->arch_rev,
+		   n->uarch_rev);
+
+	seq_printf(m,
+		   "bogomips\t: %lu.%02lu\n"
+		   "cpu MHz\t\t: %llu.%03llu\n\n",
+		   (loops_per_jiffy * HZ) / 500000,
+		   ((loops_per_jiffy * HZ) / 5000) % 100,
+		   n->freq / 1000000, (n->freq / 10000) % 100);
+
+	return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+	if (*pos == 0)
+		*pos = cpumask_first(cpu_online_mask);
+	if (*pos >= num_online_cpus())
+		return NULL;
+
+	return pos;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	*pos = cpumask_next(*pos, cpu_online_mask);
+
+	return c_start(m, pos);
+}
+
+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 = show_cpuinfo,
+};
+
+static int __init setup_cpuinfo(void)
+{
+	int cpu;
+	struct clk *clk;
+	unsigned long cpu_freq = 1000000000;
+	struct device_node *node = of_get_cpu_node(0, NULL);
+
+	clk = of_clk_get(node, 0);
+	if (IS_ERR(clk)) {
+		printk(KERN_WARNING
+		       "Device tree missing CPU 'clock' parameter. Assuming frequency is 1GHZ");
+		goto setup_cpu_freq;
+	}
+
+	cpu_freq = clk_get_rate(clk);
+
+	clk_put(clk);
+
+setup_cpu_freq:
+	of_node_put(node);
+
+	for_each_possible_cpu(cpu)
+		per_cpu_ptr(&cpu_info, cpu)->freq = cpu_freq;
+
+	return 0;
+}
+
+late_initcall(setup_cpuinfo);
-- 
2.37.2