Merge "of: cache phandle nodes to reduce cost of of_find_node_by_phandle()" (a7b916ad) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/of/base.c

+80 −4

Original line number	Diff line number	Diff line
		@@ -198,10 +198,70 @@ 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)
		for_each_of_allnodes(np)
		if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
		phandle_cache[np->phandle & phandle_cache_mask] = np;

		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);
		@@ -1093,16 +1153,32 @@ EXPORT_SYMBOL_GPL(of_modalias_node);
		*/
		struct device_node *of_find_node_by_phandle(phandle handle)
		{
		struct device_node *np;
		struct device_node *np = NULL;
		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 (np->phandle == handle) {
		if (phandle_cache)
		phandle_cache[masked_handle] = np;
		break;
		}
		}

		of_node_get(np);
		raw_spin_unlock_irqrestore(&devtree_lock, flags);
		return np;

drivers/of/of_private.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,9 @@ 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

+0 −3

Original line number	Diff line number	Diff line
		@@ -21,9 +21,6 @@
		#include <linux/string.h>
		#include <linux/slab.h>

		/* illegal phandle value (set when unresolved) */
		#define OF_PHANDLE_ILLEGAL 0xdeadbeef

		/**
		* Find a node with the give full name by recursively following any of
		* the child node links.