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of: overlay: minor restructuring
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Continue improving the readability of overlay.c.  The previous patches
renamed identifiers.  This patch is split out from the previous patches
to make the previous patches easier to review.

Changes are:
  - minor code restructuring
  - some initialization of an overlay changeset occurred outside of
    init_overlay_changeset(), move that into init_overlay_changeset()
  - consolidate freeing an overlay changeset into free_overlay_changeset()

This patch is intended to not introduce any functional change.

Signed-off-by: Frank Rowand <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
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@frowand @robherring
frowand authored and robherring committed Oct 18, 2017
1 parent 42b2e94 commit 61b4de4
Showing 1 changed file with 92 additions and 113 deletions.
205 changes: 92 additions & 113 deletions drivers/of/overlay.c
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Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,9 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs,
const struct device_node *overlay_node,
bool is_symbols_node);

static LIST_HEAD(ovcs_list);
static DEFINE_IDR(ovcs_idr);

static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain);

int of_overlay_notifier_register(struct notifier_block *nb)
Expand Down Expand Up @@ -160,8 +163,6 @@ static struct property *dup_and_fixup_symbol_prop(
kfree(new->value);
kfree(new);
return NULL;


}

/**
Expand Down Expand Up @@ -258,13 +259,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs,
if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))
break;

if (tchild) {
if (node->phandle)
return -EINVAL;

ret = build_changeset_next_level(ovcs, tchild, node, 0);
of_node_put(tchild);
} else {
if (!tchild) {
tchild = __of_node_dup(node, "%pOF/%s",
target_node, node_kbasename);
if (!tchild)
Expand All @@ -276,11 +271,15 @@ static int add_changeset_node(struct overlay_changeset *ovcs,
if (ret)
return ret;

ret = build_changeset_next_level(ovcs, tchild, node, 0);
if (ret)
return ret;
return build_changeset_next_level(ovcs, tchild, node, 0);
}

if (node->phandle)
return -EINVAL;

ret = build_changeset_next_level(ovcs, tchild, node, 0);
of_node_put(tchild);

return ret;
}

Expand Down Expand Up @@ -393,41 +392,6 @@ static struct device_node *find_target_node(struct device_node *info_node)
return NULL;
}

/**
* of_fill_overlay_info() - Fill an overlay info structure
* @ov Overlay to fill
* @info_node: Device node containing the overlay
* @ovinfo: Pointer to the overlay info structure to fill
*
* Fills an overlay info structure with the overlay information
* from a device node. This device node must have a target property
* which contains a phandle of the overlay target node, and an
* __overlay__ child node which has the overlay contents.
* Both ovinfo->target & ovinfo->overlay have their references taken.
*
* Returns 0 on success, or a negative error value.
*/
static int of_fill_overlay_info(struct overlay_changeset *ovcset,
struct device_node *info_node, struct fragment *fragment)
{
fragment->overlay = of_get_child_by_name(info_node, "__overlay__");
if (!fragment->overlay)
goto err_fail;

fragment->target = find_target_node(info_node);
if (!fragment->target)
goto err_fail;

return 0;

err_fail:
of_node_put(fragment->target);
of_node_put(fragment->overlay);

memset(fragment, 0, sizeof(*fragment));
return -EINVAL;
}

/**
* init_overlay_changeset() - initialize overlay changeset from overlay tree
* @ovcs Overlay changeset to build
Expand All @@ -438,32 +402,61 @@ static int of_fill_overlay_info(struct overlay_changeset *ovcset,
* nodes and the __symbols__ node. Any other top level node will be ignored.
*
* Returns 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error
* detected in @tree, or -ENODEV if no valid nodes found.
* detected in @tree, or -ENOSPC if idr_alloc() error.
*/
static int init_overlay_changeset(struct overlay_changeset *ovcs,
struct device_node *tree)
{
struct device_node *node;
struct device_node *node, *overlay_node;
struct fragment *fragment;
struct fragment *fragments;
int cnt, ret;

INIT_LIST_HEAD(&ovcs->ovcs_list);

of_changeset_init(&ovcs->cset);

ovcs->id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL);
if (ovcs->id <= 0)
return ovcs->id;

cnt = 0;
for_each_child_of_node(tree, node)
cnt++;

if (of_get_child_by_name(tree, "__symbols__"))
/* fragment nodes */
for_each_child_of_node(tree, node) {
overlay_node = of_get_child_by_name(node, "__overlay__");
if (overlay_node) {
cnt++;
of_node_put(overlay_node);
}
}

node = of_get_child_by_name(tree, "__symbols__");
if (node) {
cnt++;
of_node_put(node);
}

fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL);
if (!fragments)
return -ENOMEM;
if (!fragments) {
ret = -ENOMEM;
goto err_free_idr;
}

cnt = 0;
for_each_child_of_node(tree, node) {
ret = of_fill_overlay_info(ovcs, node, &fragments[cnt]);
if (!ret)
cnt++;
fragment = &fragments[cnt];
fragment->overlay = of_get_child_by_name(node, "__overlay__");
if (fragment->overlay) {
fragment->target = find_target_node(node);
if (!fragment->target) {
of_node_put(fragment->overlay);
ret = -EINVAL;
goto err_free_fragments;
} else {
cnt++;
}
}
}

node = of_get_child_by_name(tree, "__symbols__");
Expand All @@ -475,44 +468,51 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,

if (!fragment->target) {
pr_err("no symbols in root of device tree.\n");
return -EINVAL;
ret = -EINVAL;
goto err_free_fragments;
}

cnt++;
}

if (!cnt) {
kfree(fragments);
return -ENODEV;
ret = -EINVAL;
goto err_free_fragments;
}

ovcs->count = cnt;
ovcs->fragments = fragments;

return 0;


err_free_fragments:
kfree(fragments);
err_free_idr:
idr_remove(&ovcs_idr, ovcs->id);

return ret;
}

/**
* free_overlay_fragments() - Free a fragments array
* @ovcs Overlay to free the overlay info from
*
* Frees the memory of an ovcs->fragments[] array.
*/
static void free_overlay_fragments(struct overlay_changeset *ovcs)
static void free_overlay_changeset(struct overlay_changeset *ovcs)
{
int i;

/* do it in reverse */
for (i = ovcs->count - 1; i >= 0; i--) {
if (!ovcs->cset.entries.next)
return;
of_changeset_destroy(&ovcs->cset);

if (ovcs->id)
idr_remove(&ovcs_idr, ovcs->id);

for (i = 0; i < ovcs->count; i++) {
of_node_put(ovcs->fragments[i].target);
of_node_put(ovcs->fragments[i].overlay);
}

kfree(ovcs->fragments);
}

static LIST_HEAD(ovcs_list);
static DEFINE_IDR(ovcs_idr);
kfree(ovcs);
}

/**
* of_overlay_apply() - Create and apply an overlay changeset
Expand All @@ -526,63 +526,46 @@ static DEFINE_IDR(ovcs_idr);
int of_overlay_apply(struct device_node *tree)
{
struct overlay_changeset *ovcs;
int id, ret;
int ret;

ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL);
if (!ovcs)
return -ENOMEM;
ovcs->id = -1;

INIT_LIST_HEAD(&ovcs->ovcs_list);

of_changeset_init(&ovcs->cset);

mutex_lock(&of_mutex);

id = idr_alloc(&ovcs_idr, ovcs, 0, 0, GFP_KERNEL);
if (id < 0) {
ret = id;
goto err_destroy_trans;
}
ovcs->id = id;

ret = init_overlay_changeset(ovcs, tree);
if (ret) {
pr_err("init_overlay_changeset() failed for tree@%pOF\n",
tree);
goto err_free_idr;
pr_err("init_overlay_changeset() failed, ret = %d\n", ret);
goto err_free_overlay_changeset;
}

ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY);
if (ret < 0) {
pr_err("%s: Pre-apply notifier failed (ret=%d)\n",
__func__, ret);
goto err_free_overlay_fragments;
goto err_free_overlay_changeset;
}

ret = build_changeset(ovcs);
if (ret)
goto err_free_overlay_fragments;
goto err_free_overlay_changeset;

ret = __of_changeset_apply(&ovcs->cset);
if (ret)
goto err_free_overlay_fragments;
goto err_free_overlay_changeset;

list_add_tail(&ovcs->ovcs_list, &ovcs_list);

overlay_notify(ovcs, OF_OVERLAY_POST_APPLY);

mutex_unlock(&of_mutex);

return id;
return ovcs->id;

err_free_overlay_changeset:
free_overlay_changeset(ovcs);

err_free_overlay_fragments:
free_overlay_fragments(ovcs);
err_free_idr:
idr_remove(&ovcs_idr, ovcs->id);
err_destroy_trans:
of_changeset_destroy(&ovcs->cset);
kfree(ovcs);
mutex_unlock(&of_mutex);

return ret;
Expand Down Expand Up @@ -693,13 +676,14 @@ int of_overlay_remove(int ovcs_id)
}

overlay_notify(ovcs, OF_OVERLAY_PRE_REMOVE);

list_del(&ovcs->ovcs_list);

__of_changeset_revert(&ovcs->cset);

overlay_notify(ovcs, OF_OVERLAY_POST_REMOVE);
free_overlay_fragments(ovcs);
idr_remove(&ovcs_idr, ovcs_id);
of_changeset_destroy(&ovcs->cset);
kfree(ovcs);

free_overlay_changeset(ovcs);

out:
mutex_unlock(&of_mutex);
Expand All @@ -718,20 +702,15 @@ EXPORT_SYMBOL_GPL(of_overlay_remove);
int of_overlay_remove_all(void)
{
struct overlay_changeset *ovcs, *ovcs_n;

mutex_lock(&of_mutex);
int ret;

/* the tail of list is guaranteed to be safe to remove */
list_for_each_entry_safe_reverse(ovcs, ovcs_n, &ovcs_list, ovcs_list) {
list_del(&ovcs->ovcs_list);
__of_changeset_revert(&ovcs->cset);
free_overlay_fragments(ovcs);
idr_remove(&ovcs_idr, ovcs->id);
kfree(ovcs);
ret = of_overlay_remove(ovcs->id);
if (ret)
return ret;
}

mutex_unlock(&of_mutex);

return 0;
}
EXPORT_SYMBOL_GPL(of_overlay_remove_all);

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