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-rw-r--r--drivers/of/base.c130
1 files changed, 22 insertions, 108 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index db7fbc0c0893..8d173fb3552a 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -135,115 +135,38 @@ int __weak of_node_to_nid(struct device_node *np)
}
#endif
-/*
- * 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
- */
+#define OF_PHANDLE_CACHE_BITS 7
+#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
-static struct device_node **phandle_cache;
-static u32 phandle_cache_mask;
+static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
-/*
- * Caller must hold devtree_lock.
- */
-static void __of_free_phandle_cache(void)
+static u32 of_phandle_cache_hash(phandle handle)
{
- u32 cache_entries = phandle_cache_mask + 1;
- u32 k;
-
- if (!phandle_cache)
- return;
-
- for (k = 0; k < cache_entries; k++)
- of_node_put(phandle_cache[k]);
-
- kfree(phandle_cache);
- phandle_cache = NULL;
+ return hash_32(handle, OF_PHANDLE_CACHE_BITS);
}
-int of_free_phandle_cache(void)
-{
- unsigned long flags;
-
- raw_spin_lock_irqsave(&devtree_lock, flags);
-
- __of_free_phandle_cache();
-
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
- return 0;
-}
-#if !defined(CONFIG_MODULES)
-late_initcall_sync(of_free_phandle_cache);
-#endif
-
/*
* Caller must hold devtree_lock.
*/
-void __of_free_phandle_cache_entry(phandle handle)
+void __of_phandle_cache_inv_entry(phandle handle)
{
- phandle masked_handle;
+ u32 handle_hash;
struct device_node *np;
if (!handle)
return;
- masked_handle = handle & phandle_cache_mask;
-
- if (phandle_cache) {
- np = phandle_cache[masked_handle];
- if (np && handle == np->phandle) {
- of_node_put(np);
- phandle_cache[masked_handle] = NULL;
- }
- }
-}
-
-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);
-
- __of_free_phandle_cache();
-
- for_each_of_allnodes(np)
- if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
- phandles++;
-
- if (!phandles)
- goto out;
+ handle_hash = of_phandle_cache_hash(handle);
- 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) {
- of_node_get(np);
- phandle_cache[np->phandle & phandle_cache_mask] = np;
- }
-
-out:
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
+ np = phandle_cache[handle_hash];
+ if (np && handle == np->phandle)
+ phandle_cache[handle_hash] = NULL;
}
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);
@@ -253,8 +176,11 @@ void __init of_core_init(void)
pr_err("failed to register existing nodes\n");
return;
}
- for_each_of_allnodes(np)
+ for_each_of_allnodes(np) {
__of_attach_node_sysfs(np);
+ if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
+ phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
+ }
mutex_unlock(&of_mutex);
/* Symlink in /proc as required by userspace ABI */
@@ -1235,36 +1161,24 @@ struct device_node *of_find_node_by_phandle(phandle handle)
{
struct device_node *np = NULL;
unsigned long flags;
- phandle masked_handle;
+ u32 handle_hash;
if (!handle)
return NULL;
+ handle_hash = of_phandle_cache_hash(handle);
+
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 && of_node_check_flag(np, OF_DETACHED)) {
- WARN_ON(1); /* did not uncache np on node removal */
- of_node_put(np);
- phandle_cache[masked_handle] = NULL;
- np = NULL;
- }
- }
+ if (phandle_cache[handle_hash] &&
+ handle == phandle_cache[handle_hash]->phandle)
+ np = phandle_cache[handle_hash];
if (!np) {
for_each_of_allnodes(np)
if (np->phandle == handle &&
!of_node_check_flag(np, OF_DETACHED)) {
- if (phandle_cache) {
- /* will put when removed from cache */
- of_node_get(np);
- phandle_cache[masked_handle] = np;
- }
+ phandle_cache[handle_hash] = np;
break;
}
}