DT queued up for v3.16

Mostly bug fixes, but also some rework to improve path handling and device naming
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Merge tag 'dt-for-robh' of git://git.secretlab.ca/git/linux into for-next

Pull DT changes from Grant Likely:

DT queued up for v3.16

Mostly bug fixes, but also some rework to improve path handling and device naming

arch/powerpc/include/asm/dcr-mmio.h

@@ -51,10 +51,6 @@ static inline void dcr_write_mmio(dcr_host_mmio_t host,
 	out_be32(host.token + ((host.base + dcr_n) * host.stride), value);
 }
 
-extern u64 of_translate_dcr_address(struct device_node *dev,
-				    unsigned int dcr_n,
-				    unsigned int *stride);
-
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_DCR_MMIO_H */
 

arch/powerpc/sysdev/dcr.c

@@ -152,9 +152,9 @@ EXPORT_SYMBOL_GPL(dcr_resource_len);
 
 #ifdef CONFIG_PPC_DCR_MMIO
 
-u64 of_translate_dcr_address(struct device_node *dev,
-			     unsigned int dcr_n,
-			     unsigned int *out_stride)
+static u64 of_translate_dcr_address(struct device_node *dev,
+				    unsigned int dcr_n,
+				    unsigned int *out_stride)
 {
 	struct device_node *dp;
 	const u32 *p;

drivers/base/platform.c

@@ -131,9 +131,12 @@ EXPORT_SYMBOL_GPL(platform_get_resource_byname);
  */
 int platform_get_irq_byname(struct platform_device *dev, const char *name)
 {
-	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
-							  name);
+	struct resource *r;
 
+	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node)
+		return of_irq_get_byname(dev->dev.of_node, name);
+
+	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
 	return r ? r->start : -ENXIO;
 }
 EXPORT_SYMBOL_GPL(platform_get_irq_byname);

drivers/of/base.c

@@ -695,6 +695,22 @@ struct device_node *of_get_next_parent(struct device_node *node)
 }
 EXPORT_SYMBOL(of_get_next_parent);
 
+static struct device_node *__of_get_next_child(const struct device_node *node,
+						struct device_node *prev)
+{
+	struct device_node *next;
+
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling)
+		if (of_node_get(next))
+			break;
+	of_node_put(prev);
+	return next;
+}
+#define __for_each_child_of_node(parent, child) \
+	for (child = __of_get_next_child(parent, NULL); child != NULL; \
+	     child = __of_get_next_child(parent, child))
+
 /**
  *	of_get_next_child - Iterate a node childs
  *	@node:	parent node
@@ -710,11 +726,7 @@ struct device_node *of_get_next_child(const struct device_node *node,
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	next = prev ? prev->sibling : node->child;
-	for (; next; next = next->sibling)
-		if (of_node_get(next))
-			break;
-	of_node_put(prev);
+	next = __of_get_next_child(node, prev);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return next;
 }
@@ -771,23 +783,78 @@ struct device_node *of_get_child_by_name(const struct device_node *node,
 }
 EXPORT_SYMBOL(of_get_child_by_name);
 
+static struct device_node *__of_find_node_by_path(struct device_node *parent,
+						const char *path)
+{
+	struct device_node *child;
+	int len = strchrnul(path, '/') - path;
+
+	if (!len)
+		return NULL;
+
+	__for_each_child_of_node(parent, child) {
+		const char *name = strrchr(child->full_name, '/');
+		if (WARN(!name, "malformed device_node %s\n", child->full_name))
+			continue;
+		name++;
+		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
+			return child;
+	}
+	return NULL;
+}
+
 /**
  *	of_find_node_by_path - Find a node matching a full OF path
- *	@path:	The full path to match
+ *	@path: Either the full path to match, or if the path does not
+ *	       start with '/', the name of a property of the /aliases
+ *	       node (an alias).  In the case of an alias, the node
+ *	       matching the alias' value will be returned.
+ *
+ *	Valid paths:
+ *		/foo/bar	Full path
+ *		foo		Valid alias
+ *		foo/bar		Valid alias + relative path
  *
  *	Returns a node pointer with refcount incremented, use
  *	of_node_put() on it when done.
  */
 struct device_node *of_find_node_by_path(const char *path)
 {
-	struct device_node *np = of_allnodes;
+	struct device_node *np = NULL;
+	struct property *pp;
 	unsigned long flags;
 
+	if (strcmp(path, "/") == 0)
+		return of_node_get(of_allnodes);
+
+	/* The path could begin with an alias */
+	if (*path != '/') {
+		char *p = strchrnul(path, '/');
+		int len = p - path;
+
+		/* of_aliases must not be NULL */
+		if (!of_aliases)
+			return NULL;
+
+		for_each_property_of_node(of_aliases, pp) {
+			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
+				np = of_find_node_by_path(pp->value);
+				break;
+			}
+		}
+		if (!np)
+			return NULL;
+		path = p;
+	}
+
+	/* Step down the tree matching path components */
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	for (; np; np = np->allnext) {
-		if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
-		    && of_node_get(np))
-			break;
+	if (!np)
+		np = of_node_get(of_allnodes);
+	while (np && *path == '/') {
+		path++; /* Increment past '/' delimiter */
+		np = __of_find_node_by_path(np, path);
+		path = strchrnul(path, '/');
 	}
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
@@ -1800,7 +1867,7 @@ int of_update_property(struct device_node *np, struct property *newprop)
 {
 	struct property **next, *oldprop;
 	unsigned long flags;
-	int rc, found = 0;
+	int rc;
 
 	rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
 	if (rc)
@@ -1809,30 +1876,34 @@ int of_update_property(struct device_node *np, struct property *newprop)
 	if (!newprop->name)
 		return -EINVAL;
 
-	oldprop = of_find_property(np, newprop->name, NULL);
-	if (!oldprop)
-		return of_add_property(np, newprop);
-
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	next = &np->properties;
-	while (*next) {
+	oldprop = __of_find_property(np, newprop->name, NULL);
+	if (!oldprop) {
+		/* add the new node */
+		rc = __of_add_property(np, newprop);
+	} else while (*next) {
+		/* replace the node */
 		if (*next == oldprop) {
-			/* found the node */
 			newprop->next = oldprop->next;
 			*next = newprop;
 			oldprop->next = np->deadprops;
 			np->deadprops = oldprop;
-			found = 1;
 			break;
 		}
 		next = &(*next)->next;
 	}
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
-	if (!found)
-		return -ENODEV;
+	if (rc)
+		return rc;
+
+	/* At early boot, bail out and defer setup to of_init() */
+	if (!of_kset)
+		return 0;
 
 	/* Update the sysfs attribute */
-	sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
+	if (oldprop)
+		sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
 	__of_add_property_sysfs(np, newprop);
 
 	return 0;

drivers/of/fdt.c

@@ -324,7 +324,7 @@ static void __unflatten_device_tree(void *blob,
 
 	/* First pass, scan for size */
 	start = 0;
-	size = (unsigned long)unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
+	size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0);
 	size = ALIGN(size, 4);
 
 	pr_debug("  size is %lx, allocating...\n", size);
@@ -748,7 +748,7 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 		 * The longtrail doesn't have a device_type on the
 		 * /memory node, so look for the node called /memory@0.
 		 */
-		if (depth != 1 || strcmp(uname, "memory@0") != 0)
+		if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
 			return 0;
 	} else if (strcmp(type, "memory") != 0)
 		return 0;

drivers/of/irq.c

@@ -405,6 +405,28 @@ int of_irq_get(struct device_node *dev, int index)
 	return irq_create_of_mapping(&oirq);
 }
 
+/**
+ * of_irq_get_byname - Decode a node's IRQ and return it as a Linux irq number
+ * @dev: pointer to device tree node
+ * @name: irq name
+ *
+ * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
+ * is not yet created, or error code in case of any other failure.
+ */
+int of_irq_get_byname(struct device_node *dev, const char *name)
+{
+	int index;
+
+	if (unlikely(!name))
+		return -EINVAL;
+
+	index = of_property_match_string(dev, "interrupt-names", name);
+	if (index < 0)
+		return index;
+
+	return of_irq_get(dev, index);
+}
+
 /**
  * of_irq_count - Count the number of IRQs a node uses
  * @dev: pointer to device tree node

drivers/of/of_pci_irq.c

@@ -18,8 +18,6 @@ int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq
 {
 	struct device_node *dn, *ppnode;
 	struct pci_dev *ppdev;
-	u32 lspec;
-	__be32 lspec_be;
 	__be32 laddr[3];
 	u8 pin;
 	int rc;
@@ -46,7 +44,6 @@ int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq
 		return -ENODEV;
 
 	/* Now we walk up the PCI tree */
-	lspec = pin;
 	for (;;) {
 		/* Get the pci_dev of our parent */
 		ppdev = pdev->bus->self;
@@ -80,14 +77,13 @@ int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq
 		/* We can only get here if we hit a P2P bridge with no node,
 		 * let's do standard swizzling and try again
 		 */
-		lspec = pci_swizzle_interrupt_pin(pdev, lspec);
+		pin = pci_swizzle_interrupt_pin(pdev, pin);
 		pdev = ppdev;
 	}
 
 	out_irq->np = ppnode;
 	out_irq->args_count = 1;
-	out_irq->args[0] = lspec;
-	lspec_be = cpu_to_be32(lspec);
+	out_irq->args[0] = pin;
 	laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
 	laddr[1] = laddr[2] = cpu_to_be32(0);
 	return of_irq_parse_raw(laddr, out_irq);

drivers/of/platform.c

@@ -51,10 +51,6 @@ struct platform_device *of_find_device_by_node(struct device_node *np)
 }
 EXPORT_SYMBOL(of_find_device_by_node);
 
-#if defined(CONFIG_PPC_DCR)
-#include <asm/dcr.h>
-#endif
-
 #ifdef CONFIG_OF_ADDRESS
 /*
  * The following routines scan a subtree and registers a device for
@@ -68,57 +64,35 @@ EXPORT_SYMBOL(of_find_device_by_node);
  * of_device_make_bus_id - Use the device node data to assign a unique name
  * @dev: pointer to device structure that is linked to a device tree node
  *
- * This routine will first try using either the dcr-reg or the reg property
- * value to derive a unique name.  As a last resort it will use the node
- * name followed by a unique number.
+ * This routine will first try using the translated bus address to
+ * derive a unique name. If it cannot, then it will prepend names from
+ * parent nodes until a unique name can be derived.
  */
 void of_device_make_bus_id(struct device *dev)
 {
-	static atomic_t bus_no_reg_magic;
 	struct device_node *node = dev->of_node;
 	const __be32 *reg;
 	u64 addr;
-	int magic;
 
-#ifdef CONFIG_PPC_DCR
-	/*
-	 * If it's a DCR based device, use 'd' for native DCRs
-	 * and 'D' for MMIO DCRs.
-	 */
-	reg = of_get_property(node, "dcr-reg", NULL);
-	if (reg) {
-#ifdef CONFIG_PPC_DCR_NATIVE
-		dev_set_name(dev, "d%x.%s", *reg, node->name);
-#else /* CONFIG_PPC_DCR_NATIVE */
-		u64 addr = of_translate_dcr_address(node, *reg, NULL);
-		if (addr != OF_BAD_ADDR) {
-			dev_set_name(dev, "D%llx.%s",
-				     (unsigned long long)addr, node->name);
+	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
+	while (node->parent) {
+		/*
+		 * If the address can be translated, then that is as much
+		 * uniqueness as we need. Make it the first component and return
+		 */
+		reg = of_get_property(node, "reg", NULL);
+		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
+			dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
+				     (unsigned long long)addr, node->name,
+				     dev_name(dev));
 			return;
 		}
-#endif /* !CONFIG_PPC_DCR_NATIVE */
-	}
-#endif /* CONFIG_PPC_DCR */
 
-	/*
-	 * For MMIO, get the physical address
-	 */
-	reg = of_get_property(node, "reg", NULL);
-	if (reg) {
-		addr = of_translate_address(node, reg);
-		if (addr != OF_BAD_ADDR) {
-			dev_set_name(dev, "%llx.%s",
-				     (unsigned long long)addr, node->name);
-			return;
-		}
+		/* format arguments only used if dev_name() resolves to NULL */
+		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
+			     strrchr(node->full_name, '/') + 1, dev_name(dev));
+		node = node->parent;
 	}
-
-	/*
-	 * No BusID, use the node name and add a globally incremented
-	 * counter (and pray...)
-	 */
-	magic = atomic_add_return(1, &bus_no_reg_magic);
-	dev_set_name(dev, "%s.%d", node->name, magic - 1);
 }
 
 /**

drivers/of/selftest.c

@@ -31,6 +31,51 @@ static struct selftest_results {
 	} \
 }
 
+static void __init of_selftest_find_node_by_name(void)
+{
+	struct device_node *np;
+
+	np = of_find_node_by_path("/testcase-data");
+	selftest(np && !strcmp("/testcase-data", np->full_name),
+		"find /testcase-data failed\n");
+	of_node_put(np);
+
+	/* Test if trailing '/' works */
+	np = of_find_node_by_path("/testcase-data/");
+	selftest(!np, "trailing '/' on /testcase-data/ should fail\n");
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	selftest(np && !strcmp("/testcase-data/phandle-tests/consumer-a", np->full_name),
+		"find /testcase-data/phandle-tests/consumer-a failed\n");
+	of_node_put(np);
+
+	np = of_find_node_by_path("testcase-alias");
+	selftest(np && !strcmp("/testcase-data", np->full_name),
+		"find testcase-alias failed\n");
+	of_node_put(np);
+
+	/* Test if trailing '/' works on aliases */
+	np = of_find_node_by_path("testcase-alias/");
+	selftest(!np, "trailing '/' on testcase-alias/ should fail\n");
+
+	np = of_find_node_by_path("testcase-alias/phandle-tests/consumer-a");
+	selftest(np && !strcmp("/testcase-data/phandle-tests/consumer-a", np->full_name),
+		"find testcase-alias/phandle-tests/consumer-a failed\n");
+	of_node_put(np);
+
+	np = of_find_node_by_path("/testcase-data/missing-path");
+	selftest(!np, "non-existent path returned node %s\n", np->full_name);
+	of_node_put(np);
+
+	np = of_find_node_by_path("missing-alias");
+	selftest(!np, "non-existent alias returned node %s\n", np->full_name);
+	of_node_put(np);
+
+	np = of_find_node_by_path("testcase-alias/missing-path");
+	selftest(!np, "non-existent alias with relative path returned node %s\n", np->full_name);
+	of_node_put(np);
+}
+
 static void __init of_selftest_dynamic(void)
 {
 	struct device_node *np;
@@ -484,6 +529,7 @@ static int __init of_selftest(void)
 	of_node_put(np);
 
 	pr_info("start of selftest - you will see error messages\n");
+	of_selftest_find_node_by_name();
 	of_selftest_dynamic();
 	of_selftest_parse_phandle_with_args();
 	of_selftest_property_match_string();

drivers/of/testcase-data/tests-phandle.dtsi

@@ -1,6 +1,10 @@
 
 / {
-	testcase-data {
+	aliases {
+		testcase-alias = &testcase;
+	};
+
+	testcase: testcase-data {
 		security-password = "password";
 		duplicate-name = "duplicate";
 		duplicate-name { };

include/linux/of_irq.h

@@ -45,6 +45,7 @@ extern void of_irq_init(const struct of_device_id *matches);
 #ifdef CONFIG_OF_IRQ
 extern int of_irq_count(struct device_node *dev);
 extern int of_irq_get(struct device_node *dev, int index);
+extern int of_irq_get_byname(struct device_node *dev, const char *name);
 #else
 static inline int of_irq_count(struct device_node *dev)
 {
@@ -54,6 +55,10 @@ static inline int of_irq_get(struct device_node *dev, int index)
 {
 	return 0;
 }
+static inline int of_irq_get_byname(struct device_node *dev, const char *name)
+{
+	return 0;
+}
 #endif
 
 #if defined(CONFIG_OF)

include/linux/string.h

@@ -52,6 +52,9 @@ extern int strncasecmp(const char *s1, const char *s2, size_t n);
 #ifndef __HAVE_ARCH_STRCHR
 extern char * strchr(const char *,int);
 #endif
+#ifndef __HAVE_ARCH_STRCHRNUL
+extern char * strchrnul(const char *,int);
+#endif
 #ifndef __HAVE_ARCH_STRNCHR
 extern char * strnchr(const char *, size_t, int);
 #endif

lib/string.c

@@ -301,6 +301,24 @@ char *strchr(const char *s, int c)
 EXPORT_SYMBOL(strchr);
 #endif
 
+#ifndef __HAVE_ARCH_STRCHRNUL
+/**
+ * strchrnul - Find and return a character in a string, or end of string
+ * @s: The string to be searched
+ * @c: The character to search for
+ *
+ * Returns pointer to first occurrence of 'c' in s. If c is not found, then
+ * return a pointer to the null byte at the end of s.
+ */
+char *strchrnul(const char *s, int c)
+{
+	while (*s && *s != (char)c)
+		s++;
+	return (char *)s;
+}
+EXPORT_SYMBOL(strchrnul);
+#endif
+
 #ifndef __HAVE_ARCH_STRRCHR
 /**
  * strrchr - Find the last occurrence of a character in a string