1 files changed, 168 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/kdebugfs.c b/arch/loongarch/kernel/kdebugfs.c
new file mode 100644
index 000000000000..80cf64772399
--- /dev/null
+++ b/arch/loongarch/kernel/kdebugfs.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/debugfs.h>
+#include <linux/kstrtox.h>
+#include <asm/loongarch.h>
+
+struct dentry *arch_debugfs_dir;
+EXPORT_SYMBOL(arch_debugfs_dir);
+
+static int sfb_state, tso_state;
+
+static void set_sfb_state(void *info)
+{
+	int val = *(int *)info << CSR_STFILL_SHIFT;
+
+	csr_xchg32(val, CSR_STFILL, LOONGARCH_CSR_IMPCTL1);
+}
+
+static ssize_t sfb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	int s, state;
+	char str[32];
+
+	state = (csr_read32(LOONGARCH_CSR_IMPCTL1) & CSR_STFILL) >> CSR_STFILL_SHIFT;
+
+	s = snprintf(str, sizeof(str), "Boot State: %x\nCurrent State: %x\n", sfb_state, state);
+
+	if (*ppos >= s)
+		return 0;
+
+	s -= *ppos;
+	s = min_t(u32, s, count);
+
+	if (copy_to_user(buf, &str[*ppos], s))
+		return -EFAULT;
+
+	*ppos += s;
+
+	return s;
+}
+
+static ssize_t sfb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	int state;
+
+	if (kstrtoint_from_user(buf, count, 10, &state))
+		return -EFAULT;
+
+	switch (state) {
+	case 0: case 1:
+		on_each_cpu(set_sfb_state, &state, 1);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static const struct file_operations sfb_fops = {
+	.read = sfb_read,
+	.write = sfb_write,
+	.open = simple_open,
+	.llseek = default_llseek
+};
+
+#define LDSTORDER_NLD_NST        0x0 /* 000 = No Load No Store */
+#define LDSTORDER_ALD_NST        0x1 /* 001 = All Load No Store */
+#define LDSTORDER_SLD_NST        0x3 /* 011 = Same Load No Store */
+#define LDSTORDER_NLD_AST        0x4 /* 100 = No Load All Store */
+#define LDSTORDER_ALD_AST        0x5 /* 101 = All Load All Store */
+#define LDSTORDER_SLD_AST        0x7 /* 111 = Same Load All Store */
+
+static char *tso_hints[] = {
+	"No Load No Store",
+	"All Load No Store",
+	"Invalid Config",
+	"Same Load No Store",
+	"No Load All Store",
+	"All Load All Store",
+	"Invalid Config",
+	"Same Load All Store"
+};
+
+static void set_tso_state(void *info)
+{
+	int val = *(int *)info << CSR_LDSTORDER_SHIFT;
+
+	csr_xchg32(val, CSR_LDSTORDER_MASK, LOONGARCH_CSR_IMPCTL1);
+}
+
+static ssize_t tso_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	int s, state;
+	char str[240];
+
+	state = (csr_read32(LOONGARCH_CSR_IMPCTL1) & CSR_LDSTORDER_MASK) >> CSR_LDSTORDER_SHIFT;
+
+	s = snprintf(str, sizeof(str), "Boot State: %d (%s)\n"
+			               "Current State: %d (%s)\n\n"
+				       "Available States:\n"
+				       "0 (%s)\t" "1 (%s)\t" "3 (%s)\n"
+				       "4 (%s)\t" "5 (%s)\t" "7 (%s)\n",
+				       tso_state, tso_hints[tso_state], state, tso_hints[state],
+				       tso_hints[0], tso_hints[1], tso_hints[3], tso_hints[4], tso_hints[5], tso_hints[7]);
+
+	if (*ppos >= s)
+		return 0;
+
+	s -= *ppos;
+	s = min_t(u32, s, count);
+
+	if (copy_to_user(buf, &str[*ppos], s))
+		return -EFAULT;
+
+	*ppos += s;
+
+	return s;
+}
+
+static ssize_t tso_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	int state;
+
+	if (kstrtoint_from_user(buf, count, 10, &state))
+		return -EFAULT;
+
+	switch (state) {
+	case 0: case 1: case 3:
+	case 4: case 5: case 7:
+		on_each_cpu(set_tso_state, &state, 1);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static const struct file_operations tso_fops = {
+	.read = tso_read,
+	.write = tso_write,
+	.open = simple_open,
+	.llseek = default_llseek
+};
+
+static int __init arch_kdebugfs_init(void)
+{
+	unsigned int config = read_cpucfg(LOONGARCH_CPUCFG3);
+
+	arch_debugfs_dir = debugfs_create_dir("loongarch", NULL);
+
+	if (config & CPUCFG3_SFB) {
+		debugfs_create_file("sfb_state", S_IRUGO | S_IWUSR,
+			    arch_debugfs_dir, &sfb_state, &sfb_fops);
+		sfb_state = (csr_read32(LOONGARCH_CSR_IMPCTL1) & CSR_STFILL) >> CSR_STFILL_SHIFT;
+	}
+
+	if (config & (CPUCFG3_ALDORDER_CAP | CPUCFG3_ASTORDER_CAP)) {
+		debugfs_create_file("tso_state", S_IRUGO | S_IWUSR,
+			    arch_debugfs_dir, &tso_state, &tso_fops);
+		tso_state = (csr_read32(LOONGARCH_CSR_IMPCTL1) & CSR_LDSTORDER_MASK) >> CSR_LDSTORDER_SHIFT;
+	}
+
+	return 0;
+}
+postcore_initcall(arch_kdebugfs_init);