From 83262418b0ef8bda66eca7c72d4c24ae6f7b230e Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Tue, 3 May 2016 23:22:51 +1000 Subject: [PATCH] drivers/of: Return allocated memory from of_fdt_unflatten_tree() This returns the allocate memory chunk, storing the unflattened device tree, from of_fdt_unflatten_tree() so that memory chunk can be released on demand in PowerNV PCI hotplug driver. Signed-off-by: Gavin Shan Acked-by: Rob Herring Signed-off-by: Rob Herring --- drivers/of/fdt.c | 33 ++++++++++++++++++++++----------- include/linux/of_fdt.h | 6 +++--- 2 files changed, 25 insertions(+), 14 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 0d53687d4b8c..ef1ccee51af8 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -454,11 +454,14 @@ static int unflatten_dt_nodes(const void *blob, * @mynodes: The device_node tree created by the call * @dt_alloc: An allocator that provides a virtual address to memory * for the resulting tree + * + * Returns NULL on failure or the memory chunk containing the unflattened + * device tree on success. */ -static void __unflatten_device_tree(const void *blob, - struct device_node *dad, - struct device_node **mynodes, - void * (*dt_alloc)(u64 size, u64 align)) +static void *__unflatten_device_tree(const void *blob, + struct device_node *dad, + struct device_node **mynodes, + void *(*dt_alloc)(u64 size, u64 align)) { int size; void *mem; @@ -467,7 +470,7 @@ static void __unflatten_device_tree(const void *blob, if (!blob) { pr_debug("No device tree pointer\n"); - return; + return NULL; } pr_debug("Unflattening device tree:\n"); @@ -477,13 +480,13 @@ static void __unflatten_device_tree(const void *blob, if (fdt_check_header(blob)) { pr_err("Invalid device tree blob header\n"); - return; + return NULL; } /* First pass, scan for size */ size = unflatten_dt_nodes(blob, NULL, dad, NULL); if (size < 0) - return; + return NULL; size = ALIGN(size, 4); pr_debug(" size is %d, allocating...\n", size); @@ -503,6 +506,7 @@ static void __unflatten_device_tree(const void *blob, be32_to_cpup(mem + size)); pr_debug(" <- unflatten_device_tree()\n"); + return mem; } static void *kernel_tree_alloc(u64 size, u64 align) @@ -522,14 +526,21 @@ static DEFINE_MUTEX(of_fdt_unflatten_mutex); * tree of struct device_node. It also fills the "name" and "type" * pointers of the nodes so the normal device-tree walking functions * can be used. + * + * Returns NULL on failure or the memory chunk containing the unflattened + * device tree on success. */ -void of_fdt_unflatten_tree(const unsigned long *blob, - struct device_node *dad, - struct device_node **mynodes) +void *of_fdt_unflatten_tree(const unsigned long *blob, + struct device_node *dad, + struct device_node **mynodes) { + void *mem; + mutex_lock(&of_fdt_unflatten_mutex); - __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc); + mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc); mutex_unlock(&of_fdt_unflatten_mutex); + + return mem; } EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 1bffcbd56f8e..901ec01c9fba 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -37,9 +37,9 @@ extern bool of_fdt_is_big_endian(const void *blob, unsigned long node); extern int of_fdt_match(const void *blob, unsigned long node, const char *const *compat); -extern void of_fdt_unflatten_tree(const unsigned long *blob, - struct device_node *dad, - struct device_node **mynodes); +extern void *of_fdt_unflatten_tree(const unsigned long *blob, + struct device_node *dad, + struct device_node **mynodes); /* TBD: Temporary export of fdt globals - remove when code fully merged */ extern int __initdata dt_root_addr_cells; -- 2.20.1