of: Use scope based of_node_put() cleanups

Use the relatively new scope based of_node_put() cleanup to simplify
function exit handling. Doing so reduces the chances of forgetting an
of_node_put() and simplifies error paths by avoiding the need for goto
statements.

Reviewed-by: Saravana Kannan <saravanak@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240409-dt-cleanup-free-v2-3-5b419a4af38d@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/drivers/of/address.c b/drivers/of/address.c
index ae46a36059045ae39d768472960937f3d0d0651b..d669ce25b5f9c1f77246c25438fb0d18853d17c0 100644 (file)
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -486,34 +486,30 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
  * device that had registered logical PIO mapping, and the return code is
  * relative to that node.
  */
-static u64 __of_translate_address(struct device_node *dev,
+static u64 __of_translate_address(struct device_node *node,
                                  struct device_node *(*get_parent)(const struct device_node *),
                                  const __be32 *in_addr, const char *rprop,
                                  struct device_node **host)
 {
-       struct device_node *parent = NULL;
+       struct device_node *dev __free(device_node) = of_node_get(node);
+       struct device_node *parent __free(device_node) = get_parent(dev);
        struct of_bus *bus, *pbus;
        __be32 addr[OF_MAX_ADDR_CELLS];
        int na, ns, pna, pns;
-       u64 result = OF_BAD_ADDR;
 
        pr_debug("** translation for device %pOF **\n", dev);
 
-       /* Increase refcount at current level */
-       of_node_get(dev);
-
        *host = NULL;
-       /* Get parent & match bus type */
-       parent = get_parent(dev);
+
        if (parent == NULL)
-               goto bail;
+               return OF_BAD_ADDR;
        bus = of_match_bus(parent);
 
        /* Count address cells & copy address locally */
        bus->count_cells(dev, &na, &ns);
        if (!OF_CHECK_COUNTS(na, ns)) {
                pr_debug("Bad cell count for %pOF\n", dev);
-               goto bail;
+               return OF_BAD_ADDR;
        }
        memcpy(addr, in_addr, na * 4);
 
@@ -533,8 +529,7 @@ static u64 __of_translate_address(struct device_node *dev,
                /* If root, we have finished */
                if (parent == NULL) {
                        pr_debug("reached root node\n");
-                       result = of_read_number(addr, na);
-                       break;
+                       return of_read_number(addr, na);
                }
 
                /*
@@ -543,11 +538,11 @@ static u64 __of_translate_address(struct device_node *dev,
                 */
                iorange = find_io_range_by_fwnode(&dev->fwnode);
                if (iorange && (iorange->flags != LOGIC_PIO_CPU_MMIO)) {
-                       result = of_read_number(addr + 1, na - 1);
+                       u64 result = of_read_number(addr + 1, na - 1);
                        pr_debug("indirectIO matched(%pOF) 0x%llx\n",
                                 dev, result);
-                       *host = of_node_get(dev);
-                       break;
+                       *host = no_free_ptr(dev);
+                       return result;
                }
 
                /* Get new parent bus and counts */
@@ -555,7 +550,7 @@ static u64 __of_translate_address(struct device_node *dev,
                pbus->count_cells(dev, &pna, &pns);
                if (!OF_CHECK_COUNTS(pna, pns)) {
                        pr_err("Bad cell count for %pOF\n", dev);
-                       break;
+                       return OF_BAD_ADDR;
                }
 
                pr_debug("parent bus is %s (na=%d, ns=%d) on %pOF\n",
@@ -563,7 +558,7 @@ static u64 __of_translate_address(struct device_node *dev,
 
                /* Apply bus translation */
                if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
-                       break;
+                       return OF_BAD_ADDR;
 
                /* Complete the move up one level */
                na = pna;
@@ -572,11 +567,8 @@ static u64 __of_translate_address(struct device_node *dev,
 
                of_dump_addr("one level translation:", addr, na);
        }
- bail:
-       of_node_put(parent);
-       of_node_put(dev);
 
-       return result;
+       unreachable();
 }
 
 u64 of_translate_address(struct device_node *dev, const __be32 *in_addr)
@@ -654,19 +646,16 @@ EXPORT_SYMBOL(of_translate_dma_address);
 const __be32 *of_translate_dma_region(struct device_node *dev, const __be32 *prop,
                                      phys_addr_t *start, size_t *length)
 {
-       struct device_node *parent;
+       struct device_node *parent __free(device_node) = __of_get_dma_parent(dev);
        u64 address, size;
        int na, ns;
 
-       parent = __of_get_dma_parent(dev);
        if (!parent)
                return NULL;
 
        na = of_bus_n_addr_cells(parent);
        ns = of_bus_n_size_cells(parent);
 
-       of_node_put(parent);
-
        address = of_translate_dma_address(dev, prop);
        if (address == OF_BAD_ADDR)
                return NULL;
@@ -688,21 +677,19 @@ const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,
 {
        const __be32 *prop;
        unsigned int psize;
-       struct device_node *parent;
+       struct device_node *parent __free(device_node) = of_get_parent(dev);
        struct of_bus *bus;
        int onesize, i, na, ns;
 
-       /* Get parent & match bus type */
-       parent = of_get_parent(dev);
        if (parent == NULL)
                return NULL;
+
+       /* match the parent's bus type */
        bus = of_match_bus(parent);
-       if (strcmp(bus->name, "pci") && (bar_no >= 0)) {
-               of_node_put(parent);
+       if (strcmp(bus->name, "pci") && (bar_no >= 0))
                return NULL;
-       }
+
        bus->count_cells(dev, &na, &ns);
-       of_node_put(parent);
        if (!OF_CHECK_ADDR_COUNT(na))
                return NULL;
 
@@ -888,14 +875,13 @@ static u64 of_translate_ioport(struct device_node *dev, const __be32 *in_addr,
  */
 int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
 {
-       struct device_node *node = of_node_get(np);
+       struct device_node *node __free(device_node) = of_node_get(np);
        const __be32 *ranges = NULL;
        bool found_dma_ranges = false;
        struct of_range_parser parser;
        struct of_range range;
        struct bus_dma_region *r;
        int len, num_ranges = 0;
-       int ret = 0;
 
        while (node) {
                ranges = of_get_property(node, "dma-ranges", &len);
@@ -905,10 +891,9 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
                        break;
 
                /* Once we find 'dma-ranges', then a missing one is an error */
-               if (found_dma_ranges && !ranges) {
-                       ret = -ENODEV;
-                       goto out;
-               }
+               if (found_dma_ranges && !ranges)
+                       return -ENODEV;
+
                found_dma_ranges = true;
 
                node = of_get_next_dma_parent(node);
@@ -916,10 +901,8 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
 
        if (!node || !ranges) {
                pr_debug("no dma-ranges found for node(%pOF)\n", np);
-               ret = -ENODEV;
-               goto out;
+               return -ENODEV;
        }
-
        of_dma_range_parser_init(&parser, node);
        for_each_of_range(&parser, &range) {
                if (range.cpu_addr == OF_BAD_ADDR) {
@@ -930,16 +913,12 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
                num_ranges++;
        }
 
-       if (!num_ranges) {
-               ret = -EINVAL;
-               goto out;
-       }
+       if (!num_ranges)
+               return -EINVAL;
 
        r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL);
-       if (!r) {
-               ret = -ENOMEM;
-               goto out;
-       }
+       if (!r)
+               return -ENOMEM;
 
        /*
         * Record all info in the generic DMA ranges array for struct device,
@@ -957,9 +936,7 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
                r->size = range.size;
                r++;
        }
-out:
-       of_node_put(node);
-       return ret;
+       return 0;
 }
 #endif /* CONFIG_HAS_DMA */
 
@@ -1016,24 +993,18 @@ phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
  */
 bool of_dma_is_coherent(struct device_node *np)
 {
-       struct device_node *node;
-       bool is_coherent = dma_default_coherent;
-
-       node = of_node_get(np);
+       struct device_node *node __free(device_node) = of_node_get(np);
 
        while (node) {
-               if (of_property_read_bool(node, "dma-coherent")) {
-                       is_coherent = true;
-                       break;
-               }
-               if (of_property_read_bool(node, "dma-noncoherent")) {
-                       is_coherent = false;
-                       break;
-               }
+               if (of_property_read_bool(node, "dma-coherent"))
+                       return true;
+
+               if (of_property_read_bool(node, "dma-noncoherent"))
+                       return false;
+
                node = of_get_next_dma_parent(node);
        }
-       of_node_put(node);
-       return is_coherent;
+       return dma_default_coherent;
 }
 EXPORT_SYMBOL_GPL(of_dma_is_coherent);
 
@@ -1049,20 +1020,14 @@ EXPORT_SYMBOL_GPL(of_dma_is_coherent);
  */
 static bool of_mmio_is_nonposted(struct device_node *np)
 {
-       struct device_node *parent;
-       bool nonposted;
-
        if (!IS_ENABLED(CONFIG_ARCH_APPLE))
                return false;
 
-       parent = of_get_parent(np);
+       struct device_node *parent __free(device_node) = of_get_parent(np);
        if (!parent)
                return false;
 
-       nonposted = of_property_read_bool(parent, "nonposted-mmio");
-
-       of_node_put(parent);
-       return nonposted;
+       return of_property_read_bool(parent, "nonposted-mmio");
 }
 
 static int __of_address_to_resource(struct device_node *dev, int index, int bar_no,

diff --git a/drivers/of/property.c b/drivers/of/property.c
index a6358ee99b74b99a90df38c63e08943b628a7b80..c1be194412bf616717e66db133306497520b055d 100644 (file)
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -40,15 +40,12 @@
  */
 bool of_graph_is_present(const struct device_node *node)
 {
-       struct device_node *ports, *port;
+       struct device_node *ports __free(device_node) = of_get_child_by_name(node, "ports");
 
-       ports = of_get_child_by_name(node, "ports");
        if (ports)
                node = ports;
 
-       port = of_get_child_by_name(node, "port");
-       of_node_put(ports);
-       of_node_put(port);
+       struct device_node *port __free(device_node) = of_get_child_by_name(node, "port");
 
        return !!port;
 }
@@ -610,25 +607,22 @@ EXPORT_SYMBOL(of_graph_parse_endpoint);
  */
 struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
 {
-       struct device_node *node, *port;
+       struct device_node *node __free(device_node) = of_get_child_by_name(parent, "ports");
 
-       node = of_get_child_by_name(parent, "ports");
        if (node)
                parent = node;
 
-       for_each_child_of_node(parent, port) {
+       for_each_child_of_node_scoped(parent, port) {
                u32 port_id = 0;
 
                if (!of_node_name_eq(port, "port"))
                        continue;
                of_property_read_u32(port, "reg", &port_id);
                if (id == port_id)
-                       break;
+                       return_ptr(port);
        }
 
-       of_node_put(node);
-
-       return port;
+       return NULL;
 }
 EXPORT_SYMBOL(of_graph_get_port_by_id);
 
@@ -655,15 +649,13 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
         * parent port node.
         */
        if (!prev) {
-               struct device_node *node;
+               struct device_node *node __free(device_node) =
+                       of_get_child_by_name(parent, "ports");
 
-               node = of_get_child_by_name(parent, "ports");
                if (node)
                        parent = node;
 
                port = of_get_child_by_name(parent, "port");
-               of_node_put(node);
-
                if (!port) {
                        pr_debug("graph: no port node found in %pOF\n", parent);
                        return NULL;
@@ -1052,15 +1044,13 @@ static int of_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
                                          struct fwnode_endpoint *endpoint)
 {
        const struct device_node *node = to_of_node(fwnode);
-       struct device_node *port_node = of_get_parent(node);
+       struct device_node *port_node __free(device_node) = of_get_parent(node);
 
        endpoint->local_fwnode = fwnode;
 
        of_property_read_u32(port_node, "reg", &endpoint->port);
        of_property_read_u32(node, "reg", &endpoint->id);
 
-       of_node_put(port_node);
-
        return 0;
 }