// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright 2010 Benjamin Herrenschmidt, IBM Corp *                <benh@kernel.crashing.org> *     and        David Gibson, IBM Corporation. */ #include <linux/kernel.h>#include <linux/slab.h>#include <linux/export.h>#include <asm/debugfs.h>#include <asm/prom.h>#include <asm/scom.h>#include <linux/uaccess.h> const struct scom_controller *scom_controller;EXPORT_SYMBOL_GPL(scom_controller); struct device_node *scom_find_parent(struct device_node *node){	struct device_node *par, *tmp;	const u32 *p; 	for (par = of_node_get(node); par;) {		if (of_get_property(par, "scom-controller", NULL))			break;		p = of_get_property(par, "scom-parent", NULL);		tmp = par;		if (p == NULL)			par = of_get_parent(par);		else			par = of_find_node_by_phandle(*p);		of_node_put(tmp);	}	return par;}EXPORT_SYMBOL_GPL(scom_find_parent); scom_map_t scom_map_device(struct device_node *dev, int index){	struct device_node *parent;	unsigned int cells, size;	const __be32 *prop, *sprop;	u64 reg, cnt;	scom_map_t ret; 	parent = scom_find_parent(dev); 	if (parent == NULL)		return NULL; 	/*	 * We support "scom-reg" properties for adding scom registers	 * to a random device-tree node with an explicit scom-parent	 *	 * We also support the simple "reg" property if the device is	 * a direct child of a scom controller.	 *	 * In case both exist, "scom-reg" takes precedence.	 */	prop = of_get_property(dev, "scom-reg", &size);	sprop = of_get_property(parent, "#scom-cells", NULL);	if (!prop && parent == dev->parent) {		prop = of_get_property(dev, "reg", &size);		sprop = of_get_property(parent, "#address-cells", NULL);	}	if (!prop)		return NULL;	cells = sprop ? be32_to_cpup(sprop) : 1;	size >>= 2; 	if (index >= (size / (2*cells)))		return NULL; 	reg = of_read_number(&prop[index * cells * 2], cells);	cnt = of_read_number(&prop[index * cells * 2 + cells], cells); 	ret = scom_map(parent, reg, cnt);	of_node_put(parent); 	return ret;}EXPORT_SYMBOL_GPL(scom_map_device); #ifdef CONFIG_SCOM_DEBUGFSstruct scom_debug_entry {	struct device_node *dn;	struct debugfs_blob_wrapper path;	char name[16];}; static ssize_t scom_debug_read(struct file *filp, char __user *ubuf,			       size_t count, loff_t *ppos){	struct scom_debug_entry *ent = filp->private_data;	u64 __user *ubuf64 = (u64 __user *)ubuf;	loff_t off = *ppos;	ssize_t done = 0; 	u64 reg, reg_cnt, val;	scom_map_t map;	int rc; 	if (off < 0 || (off & 7) || (count & 7))		return -EINVAL;	reg = off >> 3;	reg_cnt = count >> 3; 	map = scom_map(ent->dn, reg, reg_cnt);	if (!scom_map_ok(map))		return -ENXIO; 	for (reg = 0; reg < reg_cnt; reg++) {		rc = scom_read(map, reg, &val);		if (!rc)			rc = put_user(val, ubuf64);		if (rc) {			if (!done)				done = rc;			break;		}		ubuf64++;		*ppos += 8;		done += 8;	}	scom_unmap(map);	return done;} static ssize_t scom_debug_write(struct file* filp, const char __user *ubuf,				size_t count, loff_t *ppos){	struct scom_debug_entry *ent = filp->private_data;	u64 __user *ubuf64 = (u64 __user *)ubuf;	loff_t off = *ppos;	ssize_t done = 0; 	u64 reg, reg_cnt, val;	scom_map_t map;	int rc; 	if (off < 0 || (off & 7) || (count & 7))		return -EINVAL;	reg = off >> 3;	reg_cnt = count >> 3; 	map = scom_map(ent->dn, reg, reg_cnt);	if (!scom_map_ok(map))		return -ENXIO; 	for (reg = 0; reg < reg_cnt; reg++) {		rc = get_user(val, ubuf64);		if (!rc)			rc = scom_write(map, reg,  val);		if (rc) {			if (!done)				done = rc;			break;		}		ubuf64++;		done += 8;	}	scom_unmap(map);	return done;} static const struct file_operations scom_debug_fops = {	.read =		scom_debug_read,	.write =	scom_debug_write,	.open =		simple_open,	.llseek =	default_llseek,}; static int scom_debug_init_one(struct dentry *root, struct device_node *dn,			       int i){	struct scom_debug_entry *ent;	struct dentry *dir; 	ent = kzalloc(sizeof(*ent), GFP_KERNEL);	if (!ent)		return -ENOMEM; 	ent->dn = of_node_get(dn);	snprintf(ent->name, 16, "%08x", i);	ent->path.data = (void*)kasprintf(GFP_KERNEL, "%pOF", dn);	ent->path.size = strlen((char *)ent->path.data); 	dir = debugfs_create_dir(ent->name, root);	if (!dir) {		of_node_put(dn);		kfree(ent->path.data);		kfree(ent);		return -1;	} 	debugfs_create_blob("devspec", 0400, dir, &ent->path);	debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops); 	return 0;} static int scom_debug_init(void){	struct device_node *dn;	struct dentry *root;	int i, rc; 	root = debugfs_create_dir("scom", powerpc_debugfs_root);	if (!root)		return -1; 	i = rc = 0;	for_each_node_with_property(dn, "scom-controller") {		int id = of_get_ibm_chip_id(dn);		if (id == -1)			id = i;		rc |= scom_debug_init_one(root, dn, id);		i++;	} 	return rc;}device_initcall(scom_debug_init);#endif /* CONFIG_SCOM_DEBUGFS */