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Commit 2dc9c281 authored by Chintan Pandya's avatar Chintan Pandya
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Revert "of: cache phandle nodes to reduce cost of of_find_node_by_phandle()" 



This reverts commit f7642c6a.

Original author credentials got missed inadvertently in this commit. So,
revert this commit and update new commit with proper credentials.

Change-Id: Ice9e825b7bd181eb2393a26fd317673916737851
Signed-off-by: default avatarChintan Pandya <cpandya@codeaurora.org>
parent cb57e6b4

drivers/of/base.c

+4 −82
Original line number Diff line number Diff line
@@ -197,72 +197,10 @@ int __of_attach_node_sysfs(struct device_node *np) 
	return 0;

}



static struct device_node **phandle_cache;

static u32 phandle_cache_mask;



/*

 * Assumptions behind phandle_cache implementation:

 *   - phandle property values are in a contiguous range of 1..n

 *

 * If the assumptions do not hold, then

 *   - the phandle lookup overhead reduction provided by the cache

 *     will likely be less

 */

static void of_populate_phandle_cache(void)

{

	unsigned long flags;

	u32 cache_entries;

	struct device_node *np;

	u32 phandles = 0;



	raw_spin_lock_irqsave(&devtree_lock, flags);



	kfree(phandle_cache);

	phandle_cache = NULL;



	for_each_of_allnodes(np)

		if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)

			phandles++;



	cache_entries = roundup_pow_of_two(phandles);

	phandle_cache_mask = cache_entries - 1;



	phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),

				GFP_ATOMIC);

	if (!phandle_cache)

		goto out;



	for_each_of_allnodes(np)

		if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)

			phandle_cache[np->phandle & phandle_cache_mask] = np;



out:

	raw_spin_unlock_irqrestore(&devtree_lock, flags);

}



#ifndef CONFIG_MODULES

static int __init of_free_phandle_cache(void)

{

	unsigned long flags;



	raw_spin_lock_irqsave(&devtree_lock, flags);



	kfree(phandle_cache);

	phandle_cache = NULL;



	raw_spin_unlock_irqrestore(&devtree_lock, flags);



	return 0;

}

late_initcall_sync(of_free_phandle_cache);

#endif



void __init of_core_init(void)

{

	struct device_node *np;



	of_populate_phandle_cache();



	/* Create the kset, and register existing nodes */

	mutex_lock(&of_mutex);

	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
@@ -1189,32 +1127,16 @@ EXPORT_SYMBOL_GPL(of_modalias_node); 
 */

struct device_node *of_find_node_by_phandle(phandle handle)

{

	struct device_node *np = NULL;

	struct device_node *np;

	unsigned long flags;

	phandle masked_handle;



	if (!handle)

		return NULL;



	raw_spin_lock_irqsave(&devtree_lock, flags);



	masked_handle = handle & phandle_cache_mask;



	if (phandle_cache) {

		if (phandle_cache[masked_handle] &&

		    handle == phandle_cache[masked_handle]->phandle)

			np = phandle_cache[masked_handle];

	}



	if (!np) {

	for_each_of_allnodes(np)

			if (np->phandle == handle) {

				if (phandle_cache)

					phandle_cache[masked_handle] = np;

		if (np->phandle == handle)

			break;

			}

	}



	of_node_get(np);

	raw_spin_unlock_irqrestore(&devtree_lock, flags);

	return np;

drivers/of/of_private.h

+0 −3
Original line number Diff line number Diff line
@@ -100,9 +100,6 @@ extern void __of_detach_node_sysfs(struct device_node *np); 
extern void __of_sysfs_remove_bin_file(struct device_node *np,

				       struct property *prop);



/* illegal phandle value (set when unresolved) */

#define OF_PHANDLE_ILLEGAL	0xdeadbeef



/* iterators for transactions, used for overlays */

/* forward iterator */

#define for_each_transaction_entry(_oft, _te) \

drivers/of/resolver.c

+3 −0
Original line number Diff line number Diff line
@@ -22,6 +22,9 @@ 


#include "of_private.h"



/* illegal phandle value (set when unresolved) */

#define OF_PHANDLE_ILLEGAL	0xdeadbeef



static phandle live_tree_max_phandle(void)

{

	struct device_node *node;