v4.19.13 snapshot.
diff --git a/drivers/misc/cxl/debugfs.c b/drivers/misc/cxl/debugfs.c
new file mode 100644
index 0000000..a1921d8
--- /dev/null
+++ b/drivers/misc/cxl/debugfs.c
@@ -0,0 +1,152 @@
+/*
+ * Copyright 2014 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "cxl.h"
+
+static struct dentry *cxl_debugfs;
+
+/* Helpers to export CXL mmaped IO registers via debugfs */
+static int debugfs_io_u64_get(void *data, u64 *val)
+{
+	*val = in_be64((u64 __iomem *)data);
+	return 0;
+}
+
+static int debugfs_io_u64_set(void *data, u64 val)
+{
+	out_be64((u64 __iomem *)data, val);
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(fops_io_x64, debugfs_io_u64_get, debugfs_io_u64_set,
+			 "0x%016llx\n");
+
+static struct dentry *debugfs_create_io_x64(const char *name, umode_t mode,
+					    struct dentry *parent, u64 __iomem *value)
+{
+	return debugfs_create_file_unsafe(name, mode, parent,
+					  (void __force *)value, &fops_io_x64);
+}
+
+void cxl_debugfs_add_adapter_regs_psl9(struct cxl *adapter, struct dentry *dir)
+{
+	debugfs_create_io_x64("fir1", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL9_FIR1));
+	debugfs_create_io_x64("fir_mask", 0400, dir,
+			      _cxl_p1_addr(adapter, CXL_PSL9_FIR_MASK));
+	debugfs_create_io_x64("fir_cntl", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL9_FIR_CNTL));
+	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1_addr(adapter, CXL_PSL9_TRACECFG));
+	debugfs_create_io_x64("debug", 0600, dir,
+			      _cxl_p1_addr(adapter, CXL_PSL9_DEBUG));
+	debugfs_create_io_x64("xsl-debug", 0600, dir,
+			      _cxl_p1_addr(adapter, CXL_XSL9_DBG));
+}
+
+void cxl_debugfs_add_adapter_regs_psl8(struct cxl *adapter, struct dentry *dir)
+{
+	debugfs_create_io_x64("fir1", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR1));
+	debugfs_create_io_x64("fir2", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR2));
+	debugfs_create_io_x64("fir_cntl", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_FIR_CNTL));
+	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_TRACE));
+}
+
+int cxl_debugfs_adapter_add(struct cxl *adapter)
+{
+	struct dentry *dir;
+	char buf[32];
+
+	if (!cxl_debugfs)
+		return -ENODEV;
+
+	snprintf(buf, 32, "card%i", adapter->adapter_num);
+	dir = debugfs_create_dir(buf, cxl_debugfs);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+	adapter->debugfs = dir;
+
+	debugfs_create_io_x64("err_ivte", S_IRUSR, dir, _cxl_p1_addr(adapter, CXL_PSL_ErrIVTE));
+
+	if (adapter->native->sl_ops->debugfs_add_adapter_regs)
+		adapter->native->sl_ops->debugfs_add_adapter_regs(adapter, dir);
+	return 0;
+}
+
+void cxl_debugfs_adapter_remove(struct cxl *adapter)
+{
+	debugfs_remove_recursive(adapter->debugfs);
+}
+
+void cxl_debugfs_add_afu_regs_psl9(struct cxl_afu *afu, struct dentry *dir)
+{
+	debugfs_create_io_x64("serr", S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SERR_An));
+}
+
+void cxl_debugfs_add_afu_regs_psl8(struct cxl_afu *afu, struct dentry *dir)
+{
+	debugfs_create_io_x64("sstp0", S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_SSTP0_An));
+	debugfs_create_io_x64("sstp1", S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_SSTP1_An));
+
+	debugfs_create_io_x64("fir", S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_FIR_SLICE_An));
+	debugfs_create_io_x64("serr", S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SERR_An));
+	debugfs_create_io_x64("afu_debug", S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_AFU_DEBUG_An));
+	debugfs_create_io_x64("trace", S_IRUSR | S_IWUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SLICE_TRACE));
+}
+
+int cxl_debugfs_afu_add(struct cxl_afu *afu)
+{
+	struct dentry *dir;
+	char buf[32];
+
+	if (!afu->adapter->debugfs)
+		return -ENODEV;
+
+	snprintf(buf, 32, "psl%i.%i", afu->adapter->adapter_num, afu->slice);
+	dir = debugfs_create_dir(buf, afu->adapter->debugfs);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+	afu->debugfs = dir;
+
+	debugfs_create_io_x64("sr",         S_IRUSR, dir, _cxl_p1n_addr(afu, CXL_PSL_SR_An));
+	debugfs_create_io_x64("dsisr",      S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_DSISR_An));
+	debugfs_create_io_x64("dar",        S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_DAR_An));
+
+	debugfs_create_io_x64("err_status", S_IRUSR, dir, _cxl_p2n_addr(afu, CXL_PSL_ErrStat_An));
+
+	if (afu->adapter->native->sl_ops->debugfs_add_afu_regs)
+		afu->adapter->native->sl_ops->debugfs_add_afu_regs(afu, dir);
+
+	return 0;
+}
+
+void cxl_debugfs_afu_remove(struct cxl_afu *afu)
+{
+	debugfs_remove_recursive(afu->debugfs);
+}
+
+int __init cxl_debugfs_init(void)
+{
+	struct dentry *ent;
+
+	if (!cpu_has_feature(CPU_FTR_HVMODE))
+		return 0;
+
+	ent = debugfs_create_dir("cxl", NULL);
+	if (IS_ERR(ent))
+		return PTR_ERR(ent);
+	cxl_debugfs = ent;
+
+	return 0;
+}
+
+void cxl_debugfs_exit(void)
+{
+	debugfs_remove_recursive(cxl_debugfs);
+}