From d1651b03c2df75db8eda3fbcd3a07adb337ee8b0 Mon Sep 17 00:00:00 2001 From: Frank Rowand Date: Wed, 19 Jul 2017 09:25:22 -0700 Subject: of: overlay: add overlay symbols to live device tree 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 Signed-off-by: Rob Herring --- drivers/of/overlay.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 107 insertions(+), 9 deletions(-) (limited to 'drivers/of/overlay.c') diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index fbe1980accb6..8ecfee31ab6d 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -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 struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov, + const struct property *prop) +{ + 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) + struct device_node *target, struct property *prop, + bool is_symbols_node) { - struct property *propn, *tprop; + 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); -- cgit v1.2.3-59-g8ed1b