Commit b46c7866 authored by Rob Herring's avatar Rob Herring
Browse files

Merge tag 'overlay_apply_fdt_v7-for-4.17' of... 

Merge tag 'overlay_apply_fdt_v7-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/frowand/linux into dt/next

DT overlay applying rework from Frank Rowand:
"Move duplicating and unflattening of an overlay flattened devicetree
(FDT) into the overlay application code.  To accomplish this,
of_overlay_apply() is replaced by of_overlay_fdt_apply()."
parents c11e6f0f e547c003

Documentation/devicetree/overlay-notes.txt

+2 −2
Original line number Diff line number Diff line
@@ -87,8 +87,8 @@ Overlay in-kernel API 


The API is quite easy to use.



1. Call of_overlay_apply() to create and apply an overlay changeset. The return

value is an error or a cookie identifying this overlay.

1. Call of_overlay_fdt_apply() to create and apply an overlay changeset. The

return value is an error or a cookie identifying this overlay.



2. Call of_overlay_remove() to remove and cleanup the overlay changeset

previously created via the call to of_overlay_apply(). Removal of an overlay

arch/x86/kernel/devicetree.c

+1 −1
Original line number Diff line number Diff line
@@ -259,7 +259,7 @@ static void __init dtb_apic_setup(void) 
	dtb_ioapic_setup();

}



#ifdef CONFIG_OF_FLATTREE

#ifdef CONFIG_OF_EARLY_FLATTREE

static void __init x86_flattree_get_config(void)

{

	u32 size, map_len;

drivers/of/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ config OF_RESOLVE 
config OF_OVERLAY

	bool "Device Tree overlays"

	select OF_DYNAMIC

	select OF_FLATTREE

	select OF_RESOLVE

	help

	  Overlays are a method to dynamically modify part of the kernel's

drivers/of/overlay.c

+119 −15
Original line number Diff line number Diff line
@@ -12,10 +12,12 @@ 
#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/of_fdt.h>

#include <linux/string.h>

#include <linux/ctype.h>

#include <linux/errno.h>

#include <linux/slab.h>

#include <linux/libfdt.h>

#include <linux/err.h>

#include <linux/idr.h>
@@ -33,7 +35,9 @@ struct fragment { 


/**

 * struct overlay_changeset

 * @id:			changeset identifier

 * @ovcs_list:		list on which we are located

 * @fdt:		FDT that was unflattened to create @overlay_tree

 * @overlay_tree:	expanded device tree that contains the fragment nodes

 * @count:		count of fragment structures

 * @fragments:		fragment nodes in the overlay expanded device tree
@@ -43,6 +47,7 @@ struct fragment { 
struct overlay_changeset {

	int id;

	struct list_head ovcs_list;

	const void *fdt;

	struct device_node *overlay_tree;

	int count;

	struct fragment *fragments;
@@ -483,27 +488,38 @@ static int build_changeset(struct overlay_changeset *ovcs) 
 */

static struct device_node *find_target_node(struct device_node *info_node)

{

	struct device_node *node;

	const char *path;

	u32 val;

	int ret;



	ret = of_property_read_u32(info_node, "target", &val);

	if (!ret)

		return of_find_node_by_phandle(val);

	if (!ret) {

		node = of_find_node_by_phandle(val);

		if (!node)

			pr_err("find target, node: %pOF, phandle 0x%x not found\n",

			       info_node, val);

		return node;

	}



	ret = of_property_read_string(info_node, "target-path", &path);

	if (!ret)

		return of_find_node_by_path(path);

	if (!ret) {

		node =  of_find_node_by_path(path);

		if (!node)

			pr_err("find target, node: %pOF, path '%s' not found\n",

			       info_node, path);

		return node;

	}



	pr_err("Failed to find target for node %p (%s)\n",

		info_node, info_node->name);

	pr_err("find target, node: %pOF, no target property\n", info_node);



	return NULL;

}



/**

 * init_overlay_changeset() - initialize overlay changeset from overlay tree

 * @ovcs	Overlay changeset to build

 * @ovcs:	Overlay changeset to build

 * @fdt:	the FDT that was unflattened to create @tree

 * @tree:	Contains all the overlay fragments and overlay fixup nodes

 *

 * Initialize @ovcs.  Populate @ovcs->fragments with node information from
@@ -514,7 +530,7 @@ static struct device_node *find_target_node(struct device_node *info_node) 
 * detected in @tree, or -ENOSPC if idr_alloc() error.

 */

static int init_overlay_changeset(struct overlay_changeset *ovcs,

		struct device_node *tree)

		const void *fdt, struct device_node *tree)

{

	struct device_node *node, *overlay_node;

	struct fragment *fragment;
@@ -535,6 +551,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs, 
		pr_debug("%s() tree is not root\n", __func__);



	ovcs->overlay_tree = tree;

	ovcs->fdt = fdt;



	INIT_LIST_HEAD(&ovcs->ovcs_list);
@@ -606,6 +623,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs, 
	}



	if (!cnt) {

		pr_err("no fragments or symbols in overlay\n");

		ret = -EINVAL;

		goto err_free_fragments;

	}
@@ -642,11 +660,24 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs) 
	}

	kfree(ovcs->fragments);



	/*

	 * TODO

	 *

	 * would like to: kfree(ovcs->overlay_tree);

	 * but can not since drivers may have pointers into this data

	 *

	 * would like to: kfree(ovcs->fdt);

	 * but can not since drivers may have pointers into this data

	 */



	kfree(ovcs);

}



/**

/*

 * internal documentation

 *

 * of_overlay_apply() - Create and apply an overlay changeset

 * @fdt:	the FDT that was unflattened to create @tree

 * @tree:	Expanded overlay device tree

 * @ovcs_id:	Pointer to overlay changeset id

 *
@@ -685,21 +716,29 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs) 
 * id is returned to *ovcs_id.

 */



int of_overlay_apply(struct device_node *tree, int *ovcs_id)

static int of_overlay_apply(const void *fdt, struct device_node *tree,

		int *ovcs_id)

{

	struct overlay_changeset *ovcs;

	int ret = 0, ret_revert, ret_tmp;



	*ovcs_id = 0;

	/*

	 * As of this point, fdt and tree belong to the overlay changeset.

	 * overlay changeset code is responsible for freeing them.

	 */



	if (devicetree_corrupt()) {

		pr_err("devicetree state suspect, refuse to apply overlay\n");

		kfree(fdt);

		kfree(tree);

		ret = -EBUSY;

		goto out;

	}



	ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL);

	if (!ovcs) {

		kfree(fdt);

		kfree(tree);

		ret = -ENOMEM;

		goto out;

	}
@@ -709,12 +748,17 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id) 


	ret = of_resolve_phandles(tree);

	if (ret)

		goto err_free_overlay_changeset;

		goto err_free_tree;



	ret = init_overlay_changeset(ovcs, tree);

	ret = init_overlay_changeset(ovcs, fdt, tree);

	if (ret)

		goto err_free_overlay_changeset;

		goto err_free_tree;



	/*

	 * after overlay_notify(), ovcs->overlay_tree related pointers may have

	 * leaked to drivers, so can not kfree() tree, aka ovcs->overlay_tree;

	 * and can not free fdt, aka ovcs->fdt

	 */

	ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY);

	if (ret) {

		pr_err("overlay changeset pre-apply notify error %d\n", ret);
@@ -754,6 +798,10 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id) 


	goto out_unlock;



err_free_tree:

	kfree(fdt);

	kfree(tree);



err_free_overlay_changeset:

	free_overlay_changeset(ovcs);
@@ -766,7 +814,63 @@ out: 


	return ret;

}

EXPORT_SYMBOL_GPL(of_overlay_apply);



int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,

			 int *ovcs_id)

{

	const void *new_fdt;

	int ret;

	u32 size;

	struct device_node *overlay_root;



	*ovcs_id = 0;

	ret = 0;



	if (overlay_fdt_size < sizeof(struct fdt_header) ||

	    fdt_check_header(overlay_fdt)) {

		pr_err("Invalid overlay_fdt header\n");

		return -EINVAL;

	}



	size = fdt_totalsize(overlay_fdt);

	if (overlay_fdt_size < size)

		return -EINVAL;



	/*

	 * Must create permanent copy of FDT because of_fdt_unflatten_tree()

	 * will create pointers to the passed in FDT in the unflattened tree.

	 */

	new_fdt = kmemdup(overlay_fdt, size, GFP_KERNEL);

	if (!new_fdt)

		return -ENOMEM;



	of_fdt_unflatten_tree(new_fdt, NULL, &overlay_root);

	if (!overlay_root) {

		pr_err("unable to unflatten overlay_fdt\n");

		ret = -EINVAL;

		goto out_free_new_fdt;

	}



	ret = of_overlay_apply(new_fdt, overlay_root, ovcs_id);

	if (ret < 0) {

		/*

		 * new_fdt and overlay_root now belong to the overlay

		 * changeset.

		 * overlay changeset code is responsible for freeing them.

		 */

		goto out;

	}



	return 0;





out_free_new_fdt:

	kfree(new_fdt);



out:

	return ret;

}

EXPORT_SYMBOL_GPL(of_overlay_fdt_apply);



/*

 * Find @np in @tree.

drivers/of/resolver.c

+0 −6
Original line number Diff line number Diff line
@@ -269,17 +269,11 @@ int of_resolve_phandles(struct device_node *overlay) 
		goto out;

	}



#if 0

	Temporarily disable check so that old style overlay unittests

	do not fail when of_resolve_phandles() is moved into

	of_overlay_apply().



	if (!of_node_check_flag(overlay, OF_DETACHED)) {

		pr_err("overlay not detached\n");

		err = -EINVAL;

		goto out;

	}

#endif



	phandle_delta = live_tree_max_phandle() + 1;

	adjust_overlay_phandles(overlay, phandle_delta);

CRA Git | Maintained and supported by SUSTech CRA and CCSE