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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326// SPDX-License-Identifier: GPL-2.0/* * Functions for dealing with DT resolution * * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> * Copyright (C) 2012 Texas Instruments Inc. */
#define pr_fmt(fmt) "OF: resolver: " fmt
#include <linux/cleanup.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/of.h>#include <linux/of_device.h>#include <linux/string.h>#include <linux/ctype.h>#include <linux/errno.h>#include <linux/slab.h>
#include "of_private.h"
static phandle live_tree_max_phandle(void){ struct device_node *node; phandle phandle; unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags); phandle = 0; for_each_of_allnodes(node) { if (node->phandle != OF_PHANDLE_ILLEGAL && node->phandle > phandle) phandle = node->phandle; } raw_spin_unlock_irqrestore(&devtree_lock, flags);
return phandle;}
static void adjust_overlay_phandles(struct device_node *overlay, int phandle_delta){ struct device_node *child; const struct property *prop; phandle phandle;
/* adjust node's phandle in node */ if (overlay->phandle != 0 && overlay->phandle != OF_PHANDLE_ILLEGAL) overlay->phandle += phandle_delta;
/* copy adjusted phandle into *phandle properties */ for_each_property_of_node(overlay, prop) {
if (of_prop_cmp(prop->name, "phandle") && of_prop_cmp(prop->name, "linux,phandle")) continue;
if (prop->length < 4) continue;
phandle = be32_to_cpup(prop->value); if (phandle == OF_PHANDLE_ILLEGAL) continue;
*(__be32 *)prop->value = cpu_to_be32(overlay->phandle); }
for_each_child_of_node(overlay, child) adjust_overlay_phandles(child, phandle_delta);}
static int update_usages_of_a_phandle_reference(struct device_node *overlay, const struct property *prop_fixup, phandle phandle){ struct device_node *refnode; const struct property *prop; char *value __free(kfree) = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL); char *cur, *end, *node_path, *prop_name, *s; int offset, len; int err = 0;
if (!value) return -ENOMEM;
/* prop_fixup contains a list of tuples of path:property_name:offset */ end = value + prop_fixup->length; for (cur = value; cur < end; cur += len + 1) { len = strlen(cur);
node_path = cur; s = strchr(cur, ':'); if (!s) return -EINVAL; *s++ = '\0';
prop_name = s; s = strchr(s, ':'); if (!s) return -EINVAL; *s++ = '\0';
err = kstrtoint(s, 10, &offset); if (err) return err;
refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path); if (!refnode) continue;
for_each_property_of_node(refnode, prop) { if (!of_prop_cmp(prop->name, prop_name)) break; } of_node_put(refnode);
if (!prop) return -ENOENT;
if (offset < 0 || offset + sizeof(__be32) > prop->length) return -EINVAL;
*(__be32 *)(prop->value + offset) = cpu_to_be32(phandle); }
return 0;}
/* compare nodes taking into account that 'name' strips out the @ part */static int node_name_cmp(const struct device_node *dn1, const struct device_node *dn2){ const char *n1 = kbasename(dn1->full_name); const char *n2 = kbasename(dn2->full_name);
return of_node_cmp(n1, n2);}
/* * Adjust the local phandle references by the given phandle delta. * * Subtree @local_fixups, which is overlay node __local_fixups__, * mirrors the fragment node structure at the root of the overlay. * * For each property in the fragments that contains a phandle reference, * @local_fixups has a property of the same name that contains a list * of offsets of the phandle reference(s) within the respective property * value(s). The values at these offsets will be fixed up. */static int adjust_local_phandle_references(const struct device_node *local_fixups, const struct device_node *overlay, int phandle_delta){ struct device_node *overlay_child; const struct property *prop_fix, *prop; int err, i, count; unsigned int off;
if (!local_fixups) return 0;
for_each_property_of_node(local_fixups, prop_fix) {
/* skip properties added automatically */ if (is_pseudo_property(prop_fix->name)) continue;
if ((prop_fix->length % 4) != 0 || prop_fix->length == 0) return -EINVAL; count = prop_fix->length / sizeof(__be32);
for_each_property_of_node(overlay, prop) { if (!of_prop_cmp(prop->name, prop_fix->name)) break; }
if (!prop) return -EINVAL;
for (i = 0; i < count; i++) { off = be32_to_cpu(((__be32 *)prop_fix->value)[i]); if ((off + 4) > prop->length) return -EINVAL;
be32_add_cpu(prop->value + off, phandle_delta); } }
/* * These nested loops recurse down two subtrees in parallel, where the * node names in the two subtrees match. * * The roots of the subtrees are the overlay's __local_fixups__ node * and the overlay's root node. */ for_each_child_of_node_scoped(local_fixups, child) {
for_each_child_of_node(overlay, overlay_child) if (!node_name_cmp(child, overlay_child)) { of_node_put(overlay_child); break; }
if (!overlay_child) return -EINVAL;
err = adjust_local_phandle_references(child, overlay_child, phandle_delta); if (err) return err; }
return 0;}
/** * of_resolve_phandles - Relocate and resolve overlay against live tree * * @overlay: Pointer to devicetree overlay to relocate and resolve * * Modify (relocate) values of local phandles in @overlay to a range that * does not conflict with the live expanded devicetree. Update references * to the local phandles in @overlay. Update (resolve) phandle references * in @overlay that refer to the live expanded devicetree. * * Phandle values in the live tree are in the range of * 1 .. live_tree_max_phandle(). The range of phandle values in the overlay * also begin with at 1. Adjust the phandle values in the overlay to begin * at live_tree_max_phandle() + 1. Update references to the phandles to * the adjusted phandle values. * * The name of each property in the "__fixups__" node in the overlay matches * the name of a symbol (a label) in the live tree. The values of each * property in the "__fixups__" node is a list of the property values in the * overlay that need to be updated to contain the phandle reference * corresponding to that symbol in the live tree. Update the references in * the overlay with the phandle values in the live tree. * * @overlay must be detached. * * Resolving and applying @overlay to the live expanded devicetree must be * protected by a mechanism to ensure that multiple overlays are processed * in a single threaded manner so that multiple overlays will not relocate * phandles to overlapping ranges. The mechanism to enforce this is not * yet implemented. * * Return: %0 on success or a negative error value on error. */int of_resolve_phandles(struct device_node *overlay){ struct device_node *child, *refnode; struct device_node *overlay_fixups; struct device_node __free(device_node) *local_fixups = NULL; struct property *prop; const char *refpath; phandle phandle, phandle_delta; int err;
if (!overlay) { pr_err("null overlay\n"); return -EINVAL; }
if (!of_node_check_flag(overlay, OF_DETACHED)) { pr_err("overlay not detached\n"); return -EINVAL; }
phandle_delta = live_tree_max_phandle() + 1; adjust_overlay_phandles(overlay, phandle_delta);
for_each_child_of_node(overlay, local_fixups) if (of_node_name_eq(local_fixups, "__local_fixups__")) break;
err = adjust_local_phandle_references(local_fixups, overlay, phandle_delta); if (err) return err;
overlay_fixups = NULL;
for_each_child_of_node(overlay, child) { if (of_node_name_eq(child, "__fixups__")) overlay_fixups = child; }
if (!overlay_fixups) return 0;
struct device_node __free(device_node) *tree_symbols = of_find_node_by_path("/__symbols__"); if (!tree_symbols) { pr_err("no symbols in root of device tree.\n"); return -EINVAL; }
for_each_property_of_node(overlay_fixups, prop) {
/* skip properties added automatically */ if (!of_prop_cmp(prop->name, "name")) continue;
err = of_property_read_string(tree_symbols, prop->name, &refpath); if (err) { pr_err("node label '%s' not found in live devicetree symbols table\n", prop->name); return err; }
refnode = of_find_node_by_path(refpath); if (!refnode) return -ENOENT;
phandle = refnode->phandle; of_node_put(refnode);
err = update_usages_of_a_phandle_reference(overlay, prop, phandle); if (err) break; }
if (err) pr_err("overlay phandle fixup failed: %d\n", err); return err;}EXPORT_SYMBOL_GPL(of_resolve_phandles);