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of: overlay: add overlay symbols to live device tree

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Add overlay __symbols__ properties to live tree when an overlay
is added to the live tree so that the symbols are available to
subsequent overlays.

Expected test result is new __symbols__ entries for labels from
the overlay after this commit.

Before this commit:

   Console error message near end of unittest:
      ### dt-test ### FAIL of_unittest_overlay_high_level():2296 Adding overlay 'overlay_bad_symbol' failed
      ### dt-test ### end of unittest - 190 passed, 1 failed

   The new unittest "fails" because the expected result of loading the
   new overlay is an error instead of success.

   $ # node hvac-medium-2 exists because the overlay loaded
   $ # since the duplicate symbol was not detected
   $ cd /proc/device-tree/testcase-data-2/substation@100/
   $ ls
   compatible     hvac-medium-2  motor-8        reg
   hvac-large-1   linux,phandle  name           status
   hvac-medium-1  motor-1        phandle

   $ cd /proc/device-tree/__symbols__/
   $ ls
   electric_1   lights_1     name         rides_1      spin_ctrl_2
   hvac_1       lights_2     retail_1     spin_ctrl_1

After this commit:

   Previous console error message no longer occurs, but expected error
   occurs:
      OF: overlay: Failed to apply prop @/__symbols__/hvac_1
      OF: overlay: apply failed '/__symbols__'
      ### dt-test ### end of unittest - 191 passed, 0 failed

   $ # node hvac-medium-2 does not exist because the overlay
   $ # properly failed to load due to the duplicate symbol
   $ cd /proc/device-tree/testcase-data-2/substation@100/
   $ ls
   compatible     hvac-medium-1  motor-1        name           reg
   hvac-large-1   linux,phandle  motor-8        phandle        status

   $ cd /proc/device-tree/__symbols__/
   $ ls
   electric_1      lights_1        retail_1        ride_200_right  spin_ctrl_2
   hvac_1          lights_2        ride_200        rides_1
   hvac_2          name            ride_200_left   spin_ctrl_1
   $ cat ride_200; echo
   /testcase-data-2/fairway-1/ride@200
   $ cat ride_200_left ; echo
   /testcase-data-2/fairway-1/ride@200/track@10
   $ cat ride_200_right ; echo
   /testcase-data-2/fairway-1/ride@200/track@20

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
This commit is contained in:
Frank Rowand 2017-07-19 09:25:22 -07:00 committed by Rob Herring
parent c1cd1e01fe
commit d1651b03c2
1 changed files with 108 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

118
drivers/of/overlay.c
View File

@ -35,6 +35,7 @@
struct of_overlay_info {
struct device_node *target;
struct device_node *overlay;
bool is_symbols_node;
};
/**
@ -55,7 +56,8 @@ struct of_overlay {
};
static int of_overlay_apply_one(struct of_overlay *ov,
struct device_node *target, const struct device_node *overlay);
struct device_node *target, const struct device_node *overlay,
bool is_symbols_node);
static BLOCKING_NOTIFIER_HEAD(of_overlay_chain);
@ -92,10 +94,74 @@ static int of_overlay_notify(struct of_overlay *ov,
return 0;
}
static int of_overlay_apply_single_property(struct of_overlay *ov,
struct device_node *target, struct property *prop)
static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov,
const struct property *prop)
{
struct property *propn, *tprop;
struct of_overlay_info *ovinfo;
struct property *new;
const char *overlay_name;
char *label_path;
char *symbol_path;
const char *target_path;
int k;
int label_path_len;
int overlay_name_len;
int target_path_len;
if (!prop->value)
return NULL;
symbol_path = prop->value;
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return NULL;
for (k = 0; k < ov->count; k++) {
ovinfo = &ov->ovinfo_tab[k];
overlay_name = ovinfo->overlay->full_name;
overlay_name_len = strlen(overlay_name);
if (!strncasecmp(symbol_path, overlay_name, overlay_name_len))
break;
}
if (k >= ov->count)
goto err_free;
target_path = ovinfo->target->full_name;
target_path_len = strlen(target_path);
label_path = symbol_path + overlay_name_len;
label_path_len = strlen(label_path);
new->name = kstrdup(prop->name, GFP_KERNEL);
new->length = target_path_len + label_path_len + 1;
new->value = kzalloc(new->length, GFP_KERNEL);
if (!new->name || !new->value)
goto err_free;
strcpy(new->value, target_path);
strcpy(new->value + target_path_len, label_path);
/* mark the property as dynamic */
of_property_set_flag(new, OF_DYNAMIC);
return new;
err_free:
kfree(new->name);
kfree(new->value);
kfree(new);
return NULL;
}
static int of_overlay_apply_single_property(struct of_overlay *ov,
struct device_node *target, struct property *prop,
bool is_symbols_node)
{
struct property *propn = NULL, *tprop;
/* NOTE: Multiple changes of single properties not supported */
tprop = of_find_property(target, prop->name, NULL);
@ -106,7 +172,15 @@ static int of_overlay_apply_single_property(struct of_overlay *ov,
of_prop_cmp(prop->name, "linux,phandle") == 0)
return 0;
propn = __of_prop_dup(prop, GFP_KERNEL);
if (is_symbols_node) {
/* changing a property in __symbols__ node not allowed */
if (tprop)
return -EINVAL;
propn = dup_and_fixup_symbol_prop(ov, prop);
} else {
propn = __of_prop_dup(prop, GFP_KERNEL);
}
if (propn == NULL)
return -ENOMEM;
@ -140,7 +214,7 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
return -EINVAL;
/* apply overlay recursively */
ret = of_overlay_apply_one(ov, tchild, child);
ret = of_overlay_apply_one(ov, tchild, child, 0);
of_node_put(tchild);
} else {
/* create empty tree as a target */
@ -155,7 +229,7 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
if (ret)
return ret;
ret = of_overlay_apply_one(ov, tchild, child);
ret = of_overlay_apply_one(ov, tchild, child, 0);
if (ret)
return ret;
}
@ -171,14 +245,16 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
* by using the changeset.
*/
static int of_overlay_apply_one(struct of_overlay *ov,
struct device_node *target, const struct device_node *overlay)
struct device_node *target, const struct device_node *overlay,
bool is_symbols_node)
{
struct device_node *child;
struct property *prop;
int ret;
for_each_property_of_node(overlay, prop) {
ret = of_overlay_apply_single_property(ov, target, prop);
ret = of_overlay_apply_single_property(ov, target, prop,
is_symbols_node);
if (ret) {
pr_err("Failed to apply prop @%pOF/%s\n",
target, prop->name);
@ -186,6 +262,10 @@ static int of_overlay_apply_one(struct of_overlay *ov,
}
}
/* do not allow symbols node to have any children */
if (is_symbols_node)
return 0;
for_each_child_of_node(overlay, child) {
ret = of_overlay_apply_single_device_node(ov, target, child);
if (ret != 0) {
@ -216,7 +296,8 @@ static int of_overlay_apply(struct of_overlay *ov)
for (i = 0; i < ov->count; i++) {
struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i];
err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay);
err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay,
ovinfo->is_symbols_node);
if (err != 0) {
pr_err("apply failed '%pOF'\n", ovinfo->target);
return err;
@ -314,6 +395,9 @@ static int of_build_overlay_info(struct of_overlay *ov,
for_each_child_of_node(tree, node)
cnt++;
if (of_get_child_by_name(tree, "__symbols__"))
cnt++;
ovinfo = kcalloc(cnt, sizeof(*ovinfo), GFP_KERNEL);
if (ovinfo == NULL)
return -ENOMEM;
@ -325,6 +409,20 @@ static int of_build_overlay_info(struct of_overlay *ov,
cnt++;
}
node = of_get_child_by_name(tree, "__symbols__");
if (node) {
ovinfo[cnt].overlay = node;
ovinfo[cnt].target = of_find_node_by_path("/__symbols__");
ovinfo[cnt].is_symbols_node = 1;
if (!ovinfo[cnt].target) {
pr_err("no symbols in root of device tree.\n");
return -EINVAL;
}
cnt++;
}
/* if nothing filled, return error */
if (cnt == 0) {
kfree(ovinfo);