diff options
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/base.c | 86 | ||||
| -rw-r--r-- | drivers/of/of_private.h | 3 | ||||
| -rw-r--r-- | drivers/of/resolver.c | 3 |
3 files changed, 85 insertions, 7 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 091aa9449c3a..848f549164cd 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -91,10 +91,72 @@ int __weak of_node_to_nid(struct device_node *np) } #endif +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); @@ -1021,16 +1083,32 @@ 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); - for_each_of_allnodes(np) - if (np->phandle == handle) - break; + + 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; + break; + } + } + of_node_get(np); raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index 26bb31beb03e..891d780c076a 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -132,6 +132,9 @@ 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) \ diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c index b2f645187213..65d0b7adfcd4 100644 --- a/drivers/of/resolver.c +++ b/drivers/of/resolver.c @@ -19,9 +19,6 @@ #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; |