cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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of_helpers.c (2441B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/string.h>
      3#include <linux/err.h>
      4#include <linux/slab.h>
      5#include <linux/of.h>
      6#include <asm/prom.h>
      7
      8#include "of_helpers.h"
      9
     10/**
     11 * pseries_of_derive_parent - basically like dirname(1)
     12 * @path:  the full_name of a node to be added to the tree
     13 *
     14 * Returns the node which should be the parent of the node
     15 * described by path.  E.g., for path = "/foo/bar", returns
     16 * the node with full_name = "/foo".
     17 */
     18struct device_node *pseries_of_derive_parent(const char *path)
     19{
     20	struct device_node *parent;
     21	char *parent_path = "/";
     22	const char *tail;
     23
     24	/* We do not want the trailing '/' character */
     25	tail = kbasename(path) - 1;
     26
     27	/* reject if path is "/" */
     28	if (!strcmp(path, "/"))
     29		return ERR_PTR(-EINVAL);
     30
     31	if (tail > path) {
     32		parent_path = kstrndup(path, tail - path, GFP_KERNEL);
     33		if (!parent_path)
     34			return ERR_PTR(-ENOMEM);
     35	}
     36	parent = of_find_node_by_path(parent_path);
     37	if (strcmp(parent_path, "/"))
     38		kfree(parent_path);
     39	return parent ? parent : ERR_PTR(-EINVAL);
     40}
     41
     42
     43/* Helper Routines to convert between drc_index to cpu numbers */
     44
     45int of_read_drc_info_cell(struct property **prop, const __be32 **curval,
     46			struct of_drc_info *data)
     47{
     48	const char *p = (char *)(*curval);
     49	const __be32 *p2;
     50
     51	if (!data)
     52		return -EINVAL;
     53
     54	/* Get drc-type:encode-string */
     55	data->drc_type = (char *)p;
     56	p = of_prop_next_string(*prop, p);
     57	if (!p)
     58		return -EINVAL;
     59
     60	/* Get drc-name-prefix:encode-string */
     61	data->drc_name_prefix = (char *)p;
     62	p = of_prop_next_string(*prop, p);
     63	if (!p)
     64		return -EINVAL;
     65
     66	/* Get drc-index-start:encode-int */
     67	p2 = (const __be32 *)p;
     68	data->drc_index_start = be32_to_cpu(*p2);
     69
     70	/* Get drc-name-suffix-start:encode-int */
     71	p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start);
     72	if (!p2)
     73		return -EINVAL;
     74
     75	/* Get number-sequential-elements:encode-int */
     76	p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems);
     77	if (!p2)
     78		return -EINVAL;
     79
     80	/* Get sequential-increment:encode-int */
     81	p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc);
     82	if (!p2)
     83		return -EINVAL;
     84
     85	/* Get drc-power-domain:encode-int */
     86	p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain);
     87	if (!p2)
     88		return -EINVAL;
     89
     90	/* Should now know end of current entry */
     91	(*curval) = (void *)(++p2);
     92	data->last_drc_index = data->drc_index_start +
     93		((data->num_sequential_elems - 1) * data->sequential_inc);
     94
     95	return 0;
     96}
     97EXPORT_SYMBOL(of_read_drc_info_cell);