1 files changed, 129 insertions, 127 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 55e7f5bb0549..ae03b1218b06 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -86,34 +86,46 @@ static bool __of_node_is_type(const struct device_node *np, const char *type)
 	return np && match && type && !strcmp(match, type);
 }
 
-int of_n_addr_cells(struct device_node *np)
+int of_bus_n_addr_cells(struct device_node *np)
 {
 	u32 cells;
 
-	do {
-		if (np->parent)
-			np = np->parent;
+	for (; np; np = np->parent)
 		if (!of_property_read_u32(np, "#address-cells", &cells))
 			return cells;
-	} while (np->parent);
+
 	/* No #address-cells property for the root node */
 	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 }
+
+int of_n_addr_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_addr_cells(np);
+}
 EXPORT_SYMBOL(of_n_addr_cells);
 
-int of_n_size_cells(struct device_node *np)
+int of_bus_n_size_cells(struct device_node *np)
 {
 	u32 cells;
 
-	do {
-		if (np->parent)
-			np = np->parent;
+	for (; np; np = np->parent)
 		if (!of_property_read_u32(np, "#size-cells", &cells))
 			return cells;
-	} while (np->parent);
+
 	/* No #size-cells property for the root node */
 	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 }
+
+int of_n_size_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_size_cells(np);
+}
 EXPORT_SYMBOL(of_n_size_cells);
 
 #ifdef CONFIG_NUMA
@@ -123,115 +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
- */
-
-static struct device_node **phandle_cache;
-static u32 phandle_cache_mask;
-
-/*
- * Caller must hold devtree_lock.
- */
-static void __of_free_phandle_cache(void)
-{
-	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]);
+#define OF_PHANDLE_CACHE_BITS	7
+#define OF_PHANDLE_CACHE_SZ	BIT(OF_PHANDLE_CACHE_BITS)
 
-	kfree(phandle_cache);
-	phandle_cache = NULL;
-}
+static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
 
-int of_free_phandle_cache(void)
+static u32 of_phandle_cache_hash(phandle handle)
 {
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&devtree_lock, flags);
-
-	__of_free_phandle_cache();
-
-	raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
-	return 0;
+	return hash_32(handle, OF_PHANDLE_CACHE_BITS);
 }
-#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;
+	handle_hash = of_phandle_cache_hash(handle);
 
-	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;
-
-	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);
@@ -241,8 +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 */
@@ -478,6 +416,42 @@ int of_cpu_node_to_id(struct device_node *cpu_node)
 EXPORT_SYMBOL(of_cpu_node_to_id);
 
 /**
+ * of_get_cpu_state_node - Get CPU's idle state node at the given index
+ *
+ * @cpu_node: The device node for the CPU
+ * @index: The index in the list of the idle states
+ *
+ * Two generic methods can be used to describe a CPU's idle states, either via
+ * a flattened description through the "cpu-idle-states" binding or via the
+ * hierarchical layout, using the "power-domains" and the "domain-idle-states"
+ * bindings. This function check for both and returns the idle state node for
+ * the requested index.
+ *
+ * In case an idle state node is found at @index, the refcount is incremented
+ * for it, so call of_node_put() on it when done. Returns NULL if not found.
+ */
+struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
+					  int index)
+{
+	struct of_phandle_args args;
+	int err;
+
+	err = of_parse_phandle_with_args(cpu_node, "power-domains",
+					"#power-domain-cells", 0, &args);
+	if (!err) {
+		struct device_node *state_node =
+			of_parse_phandle(args.np, "domain-idle-states", index);
+
+		of_node_put(args.np);
+		if (state_node)
+			return state_node;
+	}
+
+	return of_parse_phandle(cpu_node, "cpu-idle-states", index);
+}
+EXPORT_SYMBOL(of_get_cpu_state_node);
+
+/**
  * __of_device_is_compatible() - Check if the node matches given constraints
  * @device: pointer to node
  * @compat: required compatible string, NULL or "" for any match
@@ -1223,36 +1197,24 @@ 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;
 			}
 	}
@@ -1286,6 +1248,13 @@ int of_phandle_iterator_init(struct of_phandle_iterator *it,
 
 	memset(it, 0, sizeof(*it));
 
+	/*
+	 * one of cell_count or cells_name must be provided to determine the
+	 * argument length.
+	 */
+	if (cell_count < 0 && !cells_name)
+		return -EINVAL;
+
 	list = of_get_property(np, list_name, &size);
 	if (!list)
 		return -ENOENT;
@@ -1335,11 +1304,20 @@ int of_phandle_iterator_next(struct of_phandle_iterator *it)
 
 			if (of_property_read_u32(it->node, it->cells_name,
 						 &count)) {
-				pr_err("%pOF: could not get %s for %pOF\n",
-				       it->parent,
-				       it->cells_name,
-				       it->node);
-				goto err;
+				/*
+				 * If both cell_count and cells_name is given,
+				 * fall back to cell_count in absence
+				 * of the cells_name property
+				 */
+				if (it->cell_count >= 0) {
+					count = it->cell_count;
+				} else {
+					pr_err("%pOF: could not get %s for %pOF\n",
+					       it->parent,
+					       it->cells_name,
+					       it->node);
+					goto err;
+				}
 			}
 		} else {
 			count = it->cell_count;
@@ -1503,10 +1481,17 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na
 				const char *cells_name, int index,
 				struct of_phandle_args *out_args)
 {
+	int cell_count = -1;
+
 	if (index < 0)
 		return -EINVAL;
-	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
-					    index, out_args);
+
+	/* If cells_name is NULL we assume a cell count of 0 */
+	if (!cells_name)
+		cell_count = 0;
+
+	return __of_parse_phandle_with_args(np, list_name, cells_name,
+					    cell_count, index, out_args);
 }
 EXPORT_SYMBOL(of_parse_phandle_with_args);
 
@@ -1588,7 +1573,7 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
 	if (!pass_name)
 		goto free;
 
-	ret = __of_parse_phandle_with_args(np, list_name, cells_name, 0, index,
+	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
 					   out_args);
 	if (ret)
 		goto free;
@@ -1756,7 +1741,24 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
 	struct of_phandle_iterator it;
 	int rc, cur_index = 0;
 
-	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
+	/*
+	 * If cells_name is NULL we assume a cell count of 0. This makes
+	 * counting the phandles trivial as each 32bit word in the list is a
+	 * phandle and no arguments are to consider. So we don't iterate through
+	 * the list but just use the length to determine the phandle count.
+	 */
+	if (!cells_name) {
+		const __be32 *list;
+		int size;
+
+		list = of_get_property(np, list_name, &size);
+		if (!list)
+			return -ENOENT;
+
+		return size / sizeof(*list);
+	}
+
+	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
 	if (rc)
 		return rc;