X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=kernel%2Fresource.c;h=0bcebffc4e77d5f45571e38ddc5dcc38f40594f4;hb=4282d60689d4f21b40692029080440cc58e8a17d;hp=60c5a3856ab7a5266fabd7eef844b9d1a636d0a8;hpb=b7a40242c82cd73cfcea305f23e67d068dd8401a;p=deliverable%2Flinux.git

diff --git a/kernel/resource.c b/kernel/resource.c
index 60c5a3856ab7..0bcebffc4e77 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -491,6 +491,42 @@ int __weak page_is_ram(unsigned long pfn)
 }
 EXPORT_SYMBOL_GPL(page_is_ram);
 
+/*
+ * Search for a resouce entry that fully contains the specified region.
+ * If found, return 1 if it is RAM, 0 if not.
+ * If not found, or region is not fully contained, return -1
+ *
+ * Used by the ioremap functions to ensure the user is not remapping RAM and is
+ * a vast speed up over walking through the resource table page by page.
+ */
+int region_is_ram(resource_size_t start, unsigned long size)
+{
+	struct resource *p;
+	resource_size_t end = start + size - 1;
+	int flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	const char *name = "System RAM";
+	int ret = -1;
+
+	read_lock(&resource_lock);
+	for (p = iomem_resource.child; p ; p = p->sibling) {
+		if (end < p->start)
+			continue;
+
+		if (p->start <= start && end <= p->end) {
+			/* resource fully contains region */
+			if ((p->flags != flags) || strcmp(p->name, name))
+				ret = 0;
+			else
+				ret = 1;
+			break;
+		}
+		if (p->end < start)
+			break;	/* not found */
+	}
+	read_unlock(&resource_lock);
+	return ret;
+}
+
 void __weak arch_remove_reservations(struct resource *avail)
 {
 }
@@ -1245,6 +1281,76 @@ int release_mem_region_adjustable(struct resource *parent,
 /*
  * Managed region resource
  */
+static void devm_resource_release(struct device *dev, void *ptr)
+{
+	struct resource **r = ptr;
+
+	release_resource(*r);
+}
+
+/**
+ * devm_request_resource() - request and reserve an I/O or memory resource
+ * @dev: device for which to request the resource
+ * @root: root of the resource tree from which to request the resource
+ * @new: descriptor of the resource to request
+ *
+ * This is a device-managed version of request_resource(). There is usually
+ * no need to release resources requested by this function explicitly since
+ * that will be taken care of when the device is unbound from its driver.
+ * If for some reason the resource needs to be released explicitly, because
+ * of ordering issues for example, drivers must call devm_release_resource()
+ * rather than the regular release_resource().
+ *
+ * When a conflict is detected between any existing resources and the newly
+ * requested resource, an error message will be printed.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int devm_request_resource(struct device *dev, struct resource *root,
+			  struct resource *new)
+{
+	struct resource *conflict, **ptr;
+
+	ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	*ptr = new;
+
+	conflict = request_resource_conflict(root, new);
+	if (conflict) {
+		dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
+			new, conflict->name, conflict);
+		devres_free(ptr);
+		return -EBUSY;
+	}
+
+	devres_add(dev, ptr);
+	return 0;
+}
+EXPORT_SYMBOL(devm_request_resource);
+
+static int devm_resource_match(struct device *dev, void *res, void *data)
+{
+	struct resource **ptr = res;
+
+	return *ptr == data;
+}
+
+/**
+ * devm_release_resource() - release a previously requested resource
+ * @dev: device for which to release the resource
+ * @new: descriptor of the resource to release
+ *
+ * Releases a resource previously requested using devm_request_resource().
+ */
+void devm_release_resource(struct device *dev, struct resource *new)
+{
+	WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
+			       new));
+}
+EXPORT_SYMBOL(devm_release_resource);
+
 struct region_devres {
 	struct resource *parent;
 	resource_size_t start;