From: Frank Rowand frank.rowand@sony.com

Follows recommendations in Documentation/process/coding-style.rst, section 8, Commenting.

Some in function comments are promoted to function header comments.

Signed-off-by: Frank Rowand frank.rowand@sony.com --- drivers/of/overlay.c | 53 ++++++++++++++++++++++++---------------------------- 1 file changed, 24 insertions(+), 29 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 8ecfee31ab6d..26f63f10f4b0 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -143,7 +143,6 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov, 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; @@ -157,23 +156,24 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov,

}

+/* + * Some special properties are not updated (no error returned). + * Update of property in symbols node is not allowed. + */ 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);

- /* special properties are not meant to be updated (silent NOP) */ if (of_prop_cmp(prop->name, "name") == 0 || of_prop_cmp(prop->name, "phandle") == 0 || of_prop_cmp(prop->name, "linux,phandle") == 0) return 0;

if (is_symbols_node) { - /* changing a property in __symbols__ node not allowed */ if (tprop) return -EINVAL; propn = dup_and_fixup_symbol_prop(ov, prop); @@ -184,14 +184,19 @@ static int of_overlay_apply_single_property(struct of_overlay *ov, if (propn == NULL) return -ENOMEM;

- /* not found? add */ if (tprop == NULL) return of_changeset_add_property(&ov->cset, target, propn);

- /* found? update */ return of_changeset_update_property(&ov->cset, target, propn); }

+/* + * NOTE: Multiple mods of created nodes not supported. + * + * Return + * -ENOMEM if memory allocation fails + * -EINVAL if existing node has a phandle and overlay node has a phandle + */ static int of_overlay_apply_single_device_node(struct of_overlay *ov, struct device_node *target, struct device_node *child) { @@ -203,13 +208,11 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, if (cname == NULL) return -ENOMEM;

- /* NOTE: Multiple mods of created nodes not supported */ for_each_child_of_node(target, tchild) if (!of_node_cmp(cname, kbasename(tchild->full_name))) break;

if (tchild != NULL) { - /* new overlay phandle value conflicts with existing value */ if (child->phandle) return -EINVAL;

@@ -217,12 +220,10 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, ret = of_overlay_apply_one(ov, tchild, child, 0); of_node_put(tchild); } else { - /* create empty tree as a target */ tchild = __of_node_dup(child, "%pOF/%s", target, cname); if (!tchild) return -ENOMEM;

- /* point to parent */ tchild->parent = target;

ret = of_changeset_attach_node(&ov->cset, tchild); @@ -243,6 +244,8 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, * Note that the in case of an error the target node is left * in a inconsistent state. Error recovery should be performed * by using the changeset. + * + * Do not allow symbols node to have any children. */ static int of_overlay_apply_one(struct of_overlay *ov, struct device_node *target, const struct device_node *overlay, @@ -262,7 +265,6 @@ 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;

@@ -292,7 +294,6 @@ static int of_overlay_apply(struct of_overlay *ov) { int i, err;

- /* first we apply the overlays atomically */ for (i = 0; i < ov->count; i++) { struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i];

@@ -309,10 +310,10 @@ static int of_overlay_apply(struct of_overlay *ov)

/* * Find the target node using a number of different strategies - * in order of preference + * in order of preference: * - * "target" property containing the phandle of the target - * "target-path" property containing the path of the target + * 1) "target" property containing the phandle of the target + * 2) "target-path" property containing the path of the target */ static struct device_node *find_target_node(struct device_node *info_node) { @@ -320,12 +321,10 @@ static struct device_node *find_target_node(struct device_node *info_node) u32 val; int ret;

- /* first try to go by using the target as a phandle */ ret = of_property_read_u32(info_node, "target", &val); if (ret == 0) return of_find_node_by_phandle(val);

- /* now try to locate by path */ ret = of_property_read_string(info_node, "target-path", &path); if (ret == 0) return of_find_node_by_path(path); @@ -390,7 +389,6 @@ static int of_build_overlay_info(struct of_overlay *ov, struct of_overlay_info *ovinfo; int cnt, err;

- /* worst case; every child is a node */ cnt = 0; for_each_child_of_node(tree, node) cnt++; @@ -423,7 +421,6 @@ static int of_build_overlay_info(struct of_overlay *ov, cnt++; }

- /* if nothing filled, return error */ if (cnt == 0) { kfree(ovinfo); return -ENODEV; @@ -479,7 +476,6 @@ int of_overlay_create(struct device_node *tree) struct of_overlay *ov; int err, id;

- /* allocate the overlay structure */ ov = kzalloc(sizeof(*ov), GFP_KERNEL); if (ov == NULL) return -ENOMEM; @@ -498,7 +494,6 @@ int of_overlay_create(struct device_node *tree) } ov->id = id;

- /* build the overlay info structures */ err = of_build_overlay_info(ov, tree); if (err) { pr_err("of_build_overlay_info() failed for tree@%pOF\n", @@ -513,18 +508,15 @@ int of_overlay_create(struct device_node *tree) goto err_free_idr; }

- /* apply the overlay */ err = of_overlay_apply(ov); if (err) goto err_abort_trans;

- /* apply the changeset */ err = __of_changeset_apply(&ov->cset); if (err) goto err_revert_overlay;

- /* add to the tail of the overlay list */ list_add_tail(&ov->node, &ov_list);

of_overlay_notify(ov, OF_OVERLAY_POST_APPLY); @@ -547,13 +539,15 @@ int of_overlay_create(struct device_node *tree) } EXPORT_SYMBOL_GPL(of_overlay_create);

-/* check whether the given node, lies under the given tree */ +/* + * check whether the given node, lies under the given tree + * return 1 if under tree, else 0 + */ static int overlay_subtree_check(struct device_node *tree, struct device_node *dn) { struct device_node *child;

- /* match? */ if (tree == dn) return 1;

@@ -567,7 +561,10 @@ static int overlay_subtree_check(struct device_node *tree, return 0; }

-/* check whether this overlay is the topmost */ +/* + * check whether this overlay is the topmost + * return 1 if topmost, else 0 + */ static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) { struct of_overlay *ovt; @@ -588,7 +585,6 @@ static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) } }

- /* overlay is topmost */ return 1; }

@@ -638,7 +634,6 @@ int of_overlay_destroy(int id) goto out; }

- /* check whether the overlay is safe to remove */ if (!overlay_removal_is_ok(ov)) { err = -EBUSY; goto out;

From: Frank Rowand frank.rowand@sony.com

This patch is aimed primarily at drivers/of/overlay.c, but those changes also have a small impact in a few other files.

overlay.c is difficult to read and maintain. Improve readability: - Rename functions, types and variables to better reflect what they do and to be consistent with names in other places, such as the device tree overlay FDT (flattened device tree), and make the algorithms more clear - Use the same names consistently throughout the file - Update comments for name changes - Fix incorrect comments

This patch is intended to not introduce any functional change.

Signed-off-by: Frank Rowand frank.rowand@sony.com --- Documentation/devicetree/overlay-notes.txt | 12 +- drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c | 5 +- drivers/of/dynamic.c | 2 +- drivers/of/overlay.c | 506 ++++++++++++++------------- drivers/of/unittest.c | 20 +- include/linux/of.h | 12 +- 6 files changed, 294 insertions(+), 263 deletions(-)

diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt index eb7f2685fda1..c4aa0adf13ec 100644 --- a/Documentation/devicetree/overlay-notes.txt +++ b/Documentation/devicetree/overlay-notes.txt @@ -87,15 +87,15 @@ Overlay in-kernel API

The API is quite easy to use.

-1. Call of_overlay_create() to create and apply an overlay. The return value -is a cookie identifying this overlay. +1. Call of_overlay_apply() to create and apply an overlay changeset. The return +value is an error or a cookie identifying this overlay.

-2. Call of_overlay_destroy() to remove and cleanup the overlay previously -created via the call to of_overlay_create(). Removal of an overlay that -is stacked by another will not be permitted. +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 +changeset that is stacked by another will not be permitted.

Finally, if you need to remove all overlays in one-go, just call -of_overlay_destroy_all() which will remove every single one in the correct +of_overlay_remove_all() which will remove every single one in the correct order.

Overlay DTS Format diff --git a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c index 623a9140493c..5f5b7ba35f1d 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c @@ -247,9 +247,10 @@ static void __init tilcdc_convert_slave_node(void)

tilcdc_node_disable(slave);

- ret = of_overlay_create(overlay); + ret = of_overlay_apply(overlay); if (ret) - pr_err("%s: Creating overlay failed: %d\n", __func__, ret); + pr_err("%s: Applying overlay changeset failed: %d\n", + __func__, ret); else pr_info("%s: ti,tilcdc,slave node successfully converted\n", __func__); diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 301b6db2b48d..124510d56421 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -775,7 +775,7 @@ int of_changeset_revert(struct of_changeset *ocs) EXPORT_SYMBOL_GPL(of_changeset_revert);

/** - * of_changeset_action - Perform a changeset action + * of_changeset_action - Add an action to the tail of the changeset list * * @ocs: changeset pointer * @action: action to perform diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 8e0c7eb4858c..397ef10d1f26 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -25,67 +25,63 @@ #include "of_private.h"

/** - * struct of_overlay_info - Holds a single overlay info + * struct fragment - info about fragment nodes in overlay expanded device tree * @target: target of the overlay operation - * @overlay: pointer to the overlay contents node - * - * Holds a single overlay state, including all the overlay logs & - * records. + * @overlay: pointer to the __overlay__ node */ -struct of_overlay_info { +struct fragment { struct device_node *target; struct device_node *overlay; bool is_symbols_node; };

/** - * struct of_overlay - Holds a complete overlay transaction - * @node: List on which we are located - * @count: Count of ovinfo structures - * @ovinfo_tab: Overlay info table (count sized) - * @cset: Changeset to be used - * - * Holds a complete overlay transaction + * struct overlay_changeset + * @ovcs_list: list on which we are located + * @count: count of @fragments structures + * @fragments: info about fragment nodes in overlay expanded device tree + * @cset: changeset to apply fragments to live device tree */ -struct of_overlay { +struct overlay_changeset { int id; - struct list_head node; + struct list_head ovcs_list; int count; - struct of_overlay_info *ovinfo_tab; + struct fragment *fragments; struct of_changeset cset; };

-static int of_overlay_apply_one(struct of_overlay *ov, - struct device_node *target, const struct device_node *overlay, +static int build_changeset_next_level(struct overlay_changeset *ovcs, + struct device_node *target_node, + const struct device_node *overlay_node, bool is_symbols_node);

-static BLOCKING_NOTIFIER_HEAD(of_overlay_chain); +static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain);

int of_overlay_notifier_register(struct notifier_block *nb) { - return blocking_notifier_chain_register(&of_overlay_chain, nb); + return blocking_notifier_chain_register(&overlay_notify_chain, nb); } EXPORT_SYMBOL_GPL(of_overlay_notifier_register);

int of_overlay_notifier_unregister(struct notifier_block *nb) { - return blocking_notifier_chain_unregister(&of_overlay_chain, nb); + return blocking_notifier_chain_unregister(&overlay_notify_chain, nb); } EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister);

-static int of_overlay_notify(struct of_overlay *ov, - enum of_overlay_notify_action action) +static int overlay_notify(struct overlay_changeset *ovcs, + enum of_overlay_notify_action action) { struct of_overlay_notify_data nd; int i, ret;

- for (i = 0; i < ov->count; i++) { - struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i]; + for (i = 0; i < ovcs->count; i++) { + struct fragment *fragment = &ovcs->fragments[i];

- nd.target = ovinfo->target; - nd.overlay = ovinfo->overlay; + nd.target = fragment->target; + nd.overlay = fragment->overlay;

- ret = blocking_notifier_call_chain(&of_overlay_chain, + ret = blocking_notifier_call_chain(&overlay_notify_chain, action, &nd); if (ret) return notifier_to_errno(ret); @@ -94,10 +90,10 @@ 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) +static struct property *dup_and_fixup_symbol_prop( + struct overlay_changeset *ovcs, const struct property *prop) { - struct of_overlay_info *ovinfo; + struct fragment *fragment; struct property *new; const char *overlay_name; char *label_path; @@ -116,18 +112,18 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov, if (!new) return NULL;

- for (k = 0; k < ov->count; k++) { - ovinfo = &ov->ovinfo_tab[k]; - overlay_name = ovinfo->overlay->full_name; + for (k = 0; k < ovcs->count; k++) { + fragment = &ovcs->fragments[k]; + overlay_name = fragment->overlay->full_name; overlay_name_len = strlen(overlay_name); if (!strncasecmp(symbol_path, overlay_name, overlay_name_len)) break; }

- if (k >= ov->count) + if (k >= ovcs->count) goto err_free;

- target_path = ovinfo->target->full_name; + target_path = fragment->target->full_name; target_path_len = strlen(target_path);

label_path = symbol_path + overlay_name_len; @@ -156,81 +152,110 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov,

}

-/* +/** + * add_changeset_property() - add @overlay_prop to overlay changeset + * @ovcs: overlay changeset + * @target_node: where to place @overlay_prop in live tree + * @overlay_prop: property to add or update, from overlay tree + * is_symbols_node: 1 if @target_node is "/__symbols__" + * + * If @overlay_prop does not already exist in @target_node, add changeset entry + * to add @overlay_prop in @target_node, else add changeset entry to update + * value of @overlay_prop. + * * Some special properties are not updated (no error returned). + * * Update of property in symbols node is not allowed. + * + * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if + * invalid @overlay. */ -static int of_overlay_apply_single_property(struct of_overlay *ov, - struct device_node *target, struct property *prop, +static int add_changeset_property(struct overlay_changeset *ovcs, + struct device_node *target_node, + struct property *overlay_prop, bool is_symbols_node) { - struct property *propn = NULL, *tprop; + struct property *new_prop = NULL, *prop;

- tprop = of_find_property(target, prop->name, NULL); + prop = of_find_property(target_node, overlay_prop->name, NULL);

- if (!of_prop_cmp(prop->name, "name") || - !of_prop_cmp(prop->name, "phandle") || - !of_prop_cmp(prop->name, "linux,phandle")) + if (!of_prop_cmp(overlay_prop->name, "name") || + !of_prop_cmp(overlay_prop->name, "phandle") || + !of_prop_cmp(overlay_prop->name, "linux,phandle")) return 0;

if (is_symbols_node) { - if (tprop) + if (prop) return -EINVAL; - propn = dup_and_fixup_symbol_prop(ov, prop); + new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop); } else { - propn = __of_prop_dup(prop, GFP_KERNEL); + new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL); }

- if (!propn) + if (!new_prop) return -ENOMEM;

- if (!tprop) - return of_changeset_add_property(&ov->cset, target, propn); + if (!prop) + return of_changeset_add_property(&ovcs->cset, target_node, + new_prop);

- return of_changeset_update_property(&ov->cset, target, propn); + return of_changeset_update_property(&ovcs->cset, target_node, new_prop); }

-/* +/** + * add_changeset_node() - add @node (and children) to overlay changeset + * @ovcs: overlay changeset + * @target_node: where to place @node in live tree + * @node: node from within overlay device tree fragment + * + * If @node does not already exist in @target_node, add changeset entry + * to add @node in @target_node. + * + * If @node already exists in @target_node, and the existing node has + * a phandle, the overlay node is not allowed to have a phandle. + * + * If @node has child nodes, add the children recursively via + * build_changeset_next_level(). + * * NOTE: Multiple mods of created nodes not supported. * - * Return - * -ENOMEM if memory allocation fails - * -EINVAL if existing node has a phandle and overlay node has a phandle + * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if + * invalid @overlay. */ -static int of_overlay_apply_single_device_node(struct of_overlay *ov, - struct device_node *target, struct device_node *child) +static int add_changeset_node(struct overlay_changeset *ovcs, + struct device_node *target_node, struct device_node *node) { - const char *cname; + const char *node_kbasename; struct device_node *tchild; int ret = 0;

- cname = kbasename(child->full_name); - if (!cname) + node_kbasename = kbasename(node->full_name); + if (!node_kbasename) return -ENOMEM;

- for_each_child_of_node(target, tchild) - if (!of_node_cmp(cname, kbasename(tchild->full_name))) + for_each_child_of_node(target_node, tchild) + if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name))) break;

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

- /* apply overlay recursively */ - ret = of_overlay_apply_one(ov, tchild, child, 0); + ret = build_changeset_next_level(ovcs, tchild, node, 0); of_node_put(tchild); } else { - tchild = __of_node_dup(child, "%pOF/%s", target, cname); + tchild = __of_node_dup(node, "%pOF/%s", + target_node, node_kbasename); if (!tchild) return -ENOMEM;

- tchild->parent = target; + tchild->parent = target_node;

- ret = of_changeset_attach_node(&ov->cset, tchild); + ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) return ret;

- ret = of_overlay_apply_one(ov, tchild, child, 0); + ret = build_changeset_next_level(ovcs, tchild, node, 0); if (ret) return ret; } @@ -238,29 +263,37 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, return ret; }

-/* - * Apply a single overlay node recursively. +/** + * build_changeset_next_level() - add level of overlay changeset + * @ovcs: overlay changeset + * @target_node: where to place @overlay_node in live tree + * @overlay_node: node from within an overlay device tree fragment + * @is_symbols_node: @overlay_node is node "/__symbols__" * - * Note that the in case of an error the target node is left - * in a inconsistent state. Error recovery should be performed - * by using the changeset. + * Add the properties (if any) and nodes (if any) from @overlay_node to the + * @ovcs->cset changeset. If an added node has child nodes, they will + * be added recursively. * * Do not allow symbols node to have any children. + * + * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if + * invalid @overlay_node. */ -static int of_overlay_apply_one(struct of_overlay *ov, - struct device_node *target, const struct device_node *overlay, +static int build_changeset_next_level(struct overlay_changeset *ovcs, + struct device_node *target_node, + const struct device_node *overlay_node, 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, - is_symbols_node); + for_each_property_of_node(overlay_node, prop) { + ret = add_changeset_property(ovcs, target_node, prop, + is_symbols_node); if (ret) { pr_err("Failed to apply prop @%pOF/%s\n", - target, prop->name); + target_node, prop->name); return ret; } } @@ -268,11 +301,11 @@ static int of_overlay_apply_one(struct of_overlay *ov, if (is_symbols_node) return 0;

- for_each_child_of_node(overlay, child) { - ret = of_overlay_apply_single_device_node(ov, target, child); + for_each_child_of_node(overlay_node, child) { + ret = add_changeset_node(ovcs, target_node, child); if (ret) { - pr_err("Failed to apply single node @%pOF/%s\n", - target, child->name); + pr_err("Failed to apply node @%pOF/%s\n", + target_node, child->name); of_node_put(child); return ret; } @@ -282,26 +315,30 @@ static int of_overlay_apply_one(struct of_overlay *ov, }

/** - * of_overlay_apply() - Apply @count overlays pointed at by @ovinfo_tab - * @ov: Overlay to apply + * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments + * @ovcs: Overlay changeset * - * Applies the overlays given, while handling all error conditions - * appropriately. Either the operation succeeds, or if it fails the - * live tree is reverted to the state before the attempt. - * Returns 0, or an error if the overlay attempt failed. + * Create changeset @ovcs->cset to contain the nodes and properties of the + * overlay device tree fragments in @ovcs->fragments[]. If an error occurs, + * any portions of the changeset that were successfully created will remain + * in @ovcs->cset. + * + * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if + * invalid overlay in @ovcs->fragments[]. */ -static int of_overlay_apply(struct of_overlay *ov) +static int build_changeset(struct overlay_changeset *ovcs) { - int i, err; + int i, ret;

- for (i = 0; i < ov->count; i++) { - struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i]; + for (i = 0; i < ovcs->count; i++) { + struct fragment *fragment = &ovcs->fragments[i];

- err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay, - ovinfo->is_symbols_node); - if (err) { - pr_err("apply failed '%pOF'\n", ovinfo->target); - return err; + ret = build_changeset_next_level(ovcs, fragment->target, + fragment->overlay, + fragment->is_symbols_node); + if (ret) { + pr_err("apply failed '%pOF'\n", fragment->target); + return ret; } }

@@ -371,23 +408,24 @@ static int of_fill_overlay_info(struct of_overlay *ov, }

/** - * of_build_overlay_info() - Build an overlay info array - * @ov Overlay to build - * @tree: Device node containing all the overlays + * init_overlay_changeset() - initialize overlay changeset from overlay tree + * @ovcs Overlay changeset to build + * @tree: Contains all the overlay fragments and overlay fixup nodes * - * Helper function that given a tree containing overlay information, - * allocates and builds an overlay info array containing it, ready - * for use using of_overlay_apply. + * Initialize @ovcs. Populate @ovcs->fragments with node information from + * the top level of @tree. The relevant top level nodes are the fragment + * nodes and the __symbols__ node. Any other top level node will be ignored. * - * Returns 0 on success with the @cntp @ovinfop pointers valid, - * while on error a negative error value is returned. + * Returns 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error + * detected in @tree, or -ENODEV if no valid nodes found. */ -static int of_build_overlay_info(struct of_overlay *ov, +static int init_overlay_changeset(struct overlay_changeset *ovcs, struct device_node *tree) { struct device_node *node; - struct of_overlay_info *ovinfo; - int cnt, err; + struct fragment *fragment; + struct fragment *fragments; + int cnt, ret;

cnt = 0; for_each_child_of_node(tree, node) @@ -396,24 +434,25 @@ static int of_build_overlay_info(struct of_overlay *ov, if (of_get_child_by_name(tree, "__symbols__")) cnt++;

- ovinfo = kcalloc(cnt, sizeof(*ovinfo), GFP_KERNEL); - if (!ovinfo) + fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL); + if (!fragments) return -ENOMEM;

cnt = 0; for_each_child_of_node(tree, node) { - err = of_fill_overlay_info(ov, node, &ovinfo[cnt]); - if (!err) + ret = of_fill_overlay_info(ovcs, node, &fragments[cnt]); + if (!ret) 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; + fragment = &fragments[cnt]; + fragment->overlay = node; + fragment->target = of_find_node_by_path("/__symbols__"); + fragment->is_symbols_node = 1;

- if (!ovinfo[cnt].target) { + if (!fragment->target) { pr_err("no symbols in root of device tree.\n"); return -EINVAL; } @@ -422,137 +461,127 @@ static int of_build_overlay_info(struct of_overlay *ov, }

if (!cnt) { - kfree(ovinfo); + kfree(fragments); return -ENODEV; }

- ov->count = cnt; - ov->ovinfo_tab = ovinfo; + ovcs->count = cnt; + ovcs->fragments = fragments;

return 0; }

/** - * of_free_overlay_info() - Free an overlay info array - * @ov Overlay to free the overlay info from - * @ovinfo_tab: Array of overlay_info's to free + * free_overlay_fragments() - Free a fragments array + * @ovcs Overlay to free the overlay info from * - * Releases the memory of a previously allocated ovinfo array - * by of_build_overlay_info. - * Returns 0, or an error if the arguments are bogus. + * Frees the memory of an ovcs->fragments[] array. */ -static int of_free_overlay_info(struct of_overlay *ov) +static void free_overlay_fragments(struct overlay_changeset *ovcs) { - struct of_overlay_info *ovinfo; int i;

/* do it in reverse */ - for (i = ov->count - 1; i >= 0; i--) { - ovinfo = &ov->ovinfo_tab[i]; - - of_node_put(ovinfo->target); - of_node_put(ovinfo->overlay); + for (i = ovcs->count - 1; i >= 0; i--) { + of_node_put(ovcs->fragments[i].target); + of_node_put(ovcs->fragments[i].overlay); } - kfree(ov->ovinfo_tab);

- return 0; + kfree(ovcs->fragments); }

-static LIST_HEAD(ov_list); -static DEFINE_IDR(ov_idr); +static LIST_HEAD(ovcs_list); +static DEFINE_IDR(ovcs_idr);

/** - * of_overlay_create() - Create and apply an overlay - * @tree: Device node containing all the overlays + * of_overlay_apply() - Create and apply an overlay changeset + * @tree: Expanded overlay device tree * - * Creates and applies an overlay while also keeping track - * of the overlay in a list. This list can be used to prevent - * illegal overlay removals. + * Creates and applies an overlay changeset. If successful, the overlay + * changeset is added to the overlay changeset list. * - * Returns the id of the created overlay, or a negative error number + * Returns the id of the created overlay changeset, or a negative error number */ -int of_overlay_create(struct device_node *tree) +int of_overlay_apply(struct device_node *tree) { - struct of_overlay *ov; - int err, id; + struct overlay_changeset *ovcs; + int id, ret;

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

- INIT_LIST_HEAD(&ov->node); + INIT_LIST_HEAD(&ovcs->ovcs_list);

- of_changeset_init(&ov->cset); + of_changeset_init(&ovcs->cset);

mutex_lock(&of_mutex);

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

- err = of_build_overlay_info(ov, tree); - if (err) { - pr_err("of_build_overlay_info() failed for tree@%pOF\n", + ret = init_overlay_changeset(ovcs, tree); + if (ret) { + pr_err("init_overlay_changeset() failed for tree@%pOF\n", tree); goto err_free_idr; }

- err = of_overlay_notify(ov, OF_OVERLAY_PRE_APPLY); - if (err < 0) { - pr_err("%s: Pre-apply notifier failed (err=%d)\n", - __func__, err); - goto err_free_idr; + 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; }

- err = of_overlay_apply(ov); - if (err) - goto err_abort_trans; + ret = build_changeset(ovcs); + if (ret) + goto err_free_overlay_fragments;

- err = __of_changeset_apply(&ov->cset); - if (err) - goto err_revert_overlay; + ret = __of_changeset_apply(&ovcs->cset); + if (ret) + goto err_free_overlay_fragments;

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

- list_add_tail(&ov->node, &ov_list); - - of_overlay_notify(ov, OF_OVERLAY_POST_APPLY); + overlay_notify(ovcs, OF_OVERLAY_POST_APPLY);

mutex_unlock(&of_mutex);

return id;

-err_revert_overlay: -err_abort_trans: - of_free_overlay_info(ov); +err_free_overlay_fragments: + free_overlay_fragments(ovcs); err_free_idr: - idr_remove(&ov_idr, ov->id); + idr_remove(&ovcs_idr, ovcs->id); err_destroy_trans: - of_changeset_destroy(&ov->cset); - kfree(ov); + of_changeset_destroy(&ovcs->cset); + kfree(ovcs); mutex_unlock(&of_mutex);

- return err; + return ret; } -EXPORT_SYMBOL_GPL(of_overlay_create); +EXPORT_SYMBOL_GPL(of_overlay_apply);

/* - * check whether the given node, lies under the given tree - * return 1 if under tree, else 0 + * Find @np in @tree. + * + * Returns 1 if @np is @tree or is contained in @tree, else 0 */ -static int overlay_subtree_check(struct device_node *tree, - struct device_node *dn) +static int find_node(struct device_node *tree, struct device_node *np) { struct device_node *child;

- if (tree == dn) + if (tree == np) return 1;

for_each_child_of_node(tree, child) { - if (overlay_subtree_check(child, dn)) { + if (find_node(child, np)) { of_node_put(child); return 1; } @@ -562,30 +591,32 @@ static int overlay_subtree_check(struct device_node *tree, }

/* - * check whether this overlay is the topmost - * return 1 if topmost, else 0 + * Is @remove_ce_np a child of or the same as any + * node in an overlay changeset more topmost than @remove_ovcs? + * + * Returns 1 if found, else 0 */ -static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) +static int node_in_later_cs(struct overlay_changeset *remove_ovcs, + struct device_node *remove_ce_np) { - struct of_overlay *ovt; + struct overlay_changeset *ovcs; struct of_changeset_entry *ce;

- list_for_each_entry_reverse(ovt, &ov_list, node) { - /* if we hit ourselves, we're done */ - if (ovt == ov) + list_for_each_entry_reverse(ovcs, &ovcs_list, ovcs_list) { + if (ovcs == remove_ovcs) break;

- /* check against each subtree affected by this overlay */ - list_for_each_entry(ce, &ovt->cset.entries, node) { - if (overlay_subtree_check(ce->np, dn)) { + list_for_each_entry(ce, &ovcs->cset.entries, node) { + if (find_node(ce->np, remove_ce_np)) { pr_err("%s: #%d clashes #%d @%pOF\n", - __func__, ov->id, ovt->id, dn); - return 0; + __func__, remove_ovcs->id, ovcs->id, + remove_ce_np); + return 1; } } }

- return 1; + return 0; }

/* @@ -598,13 +629,13 @@ static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) * the one closest to the tail. If another overlay has affected this * device node and is closest to the tail, then removal is not permited. */ -static int overlay_removal_is_ok(struct of_overlay *ov) +static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs) { - struct of_changeset_entry *ce; + struct of_changeset_entry *remove_ce;

- list_for_each_entry(ce, &ov->cset.entries, node) { - if (!overlay_is_topmost(ov, ce->np)) { - pr_err("overlay #%d is not topmost\n", ov->id); + list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) { + if (node_in_later_cs(remove_ovcs, remove_ce->np)) { + pr_err("overlay #%d is not topmost\n", remove_ovcs->id); return 0; } } @@ -613,74 +644,73 @@ static int overlay_removal_is_ok(struct of_overlay *ov) }

/** - * of_overlay_destroy() - Removes an overlay - * @id: Overlay id number returned by a previous call to of_overlay_create + * of_overlay_remove() - Revert and free an overlay changeset + * @ovcs_id: Overlay changeset id number * - * Removes an overlay if it is permissible. + * Removes an overlay if it is permissible. ovcs_id was previously returned + * by of_overlay_apply(). * * Returns 0 on success, or a negative error number */ -int of_overlay_destroy(int id) +int of_overlay_remove(int ovcs_id) { - struct of_overlay *ov; - int err; + struct overlay_changeset *ovcs; + int ret = 0;

mutex_lock(&of_mutex);

- ov = idr_find(&ov_idr, id); - if (!ov) { - err = -ENODEV; - pr_err("destroy: Could not find overlay #%d\n", id); + ovcs = idr_find(&ovcs_idr, ovcs_id); + if (!ovcs) { + ret = -ENODEV; + pr_err("remove: Could not find overlay #%d\n", ovcs_id); goto out; }

- if (!overlay_removal_is_ok(ov)) { - err = -EBUSY; + if (!overlay_removal_is_ok(ovcs)) { + ret = -EBUSY; goto out; }

- of_overlay_notify(ov, OF_OVERLAY_PRE_REMOVE); - list_del(&ov->node); - __of_changeset_revert(&ov->cset); - of_overlay_notify(ov, OF_OVERLAY_POST_REMOVE); - of_free_overlay_info(ov); - idr_remove(&ov_idr, id); - of_changeset_destroy(&ov->cset); - kfree(ov); - - err = 0; + 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);

out: mutex_unlock(&of_mutex);

- return err; + return ret; } -EXPORT_SYMBOL_GPL(of_overlay_destroy); +EXPORT_SYMBOL_GPL(of_overlay_remove);

/** - * of_overlay_destroy_all() - Removes all overlays from the system + * of_overlay_remove_all() - Reverts and frees all overlay changesets * * Removes all overlays from the system in the correct order. * * Returns 0 on success, or a negative error number */ -int of_overlay_destroy_all(void) +int of_overlay_remove_all(void) { - struct of_overlay *ov, *ovn; + struct overlay_changeset *ovcs, *ovcs_n;

mutex_lock(&of_mutex);

/* the tail of list is guaranteed to be safe to remove */ - list_for_each_entry_safe_reverse(ov, ovn, &ov_list, node) { - list_del(&ov->node); - __of_changeset_revert(&ov->cset); - of_free_overlay_info(ov); - idr_remove(&ov_idr, ov->id); - kfree(ov); + 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); }

mutex_unlock(&of_mutex);

return 0; } -EXPORT_SYMBOL_GPL(of_overlay_destroy_all); +EXPORT_SYMBOL_GPL(of_overlay_remove_all); diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index 29a35cb1da64..e19dcd80e7a7 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -1231,7 +1231,7 @@ static void of_unittest_destroy_tracked_overlays(void) if (!(overlay_id_bits[BIT_WORD(id)] & BIT_MASK(id))) continue;

- ret = of_overlay_destroy(id + overlay_first_id); + ret = of_overlay_remove(id + overlay_first_id); if (ret == -ENODEV) { pr_warn("%s: no overlay to destroy for #%d\n", __func__, id + overlay_first_id); @@ -1263,7 +1263,7 @@ static int of_unittest_apply_overlay(int overlay_nr, int unittest_nr, goto out; }

- ret = of_overlay_create(np); + ret = of_overlay_apply(np); if (ret < 0) { unittest(0, "could not create overlay from "%s"\n", overlay_path(overlay_nr)); @@ -1348,7 +1348,7 @@ static int of_unittest_apply_revert_overlay_check(int overlay_nr, return -EINVAL; }

- ret = of_overlay_destroy(ov_id); + ret = of_overlay_remove(ov_id); if (ret != 0) { unittest(0, "overlay @"%s" failed to be destroyed @"%s"\n", overlay_path(overlay_nr), @@ -1477,7 +1477,7 @@ static void of_unittest_overlay_6(void) return; }

- ret = of_overlay_create(np); + ret = of_overlay_apply(np); if (ret < 0) { unittest(0, "could not create overlay from "%s"\n", overlay_path(overlay_nr + i)); @@ -1501,7 +1501,7 @@ static void of_unittest_overlay_6(void) }

for (i = 1; i >= 0; i--) { - ret = of_overlay_destroy(ov_id[i]); + ret = of_overlay_remove(ov_id[i]); if (ret != 0) { unittest(0, "overlay @"%s" failed destroy @"%s"\n", overlay_path(overlay_nr + i), @@ -1547,7 +1547,7 @@ static void of_unittest_overlay_8(void) return; }

- ret = of_overlay_create(np); + ret = of_overlay_apply(np); if (ret < 0) { unittest(0, "could not create overlay from "%s"\n", overlay_path(overlay_nr + i)); @@ -1558,7 +1558,7 @@ static void of_unittest_overlay_8(void) }

/* now try to remove first overlay (it should fail) */ - ret = of_overlay_destroy(ov_id[0]); + ret = of_overlay_remove(ov_id[0]); if (ret == 0) { unittest(0, "overlay @"%s" was destroyed @"%s"\n", overlay_path(overlay_nr + 0), @@ -1569,7 +1569,7 @@ static void of_unittest_overlay_8(void)

/* removing them in order should work */ for (i = 1; i >= 0; i--) { - ret = of_overlay_destroy(ov_id[i]); + ret = of_overlay_remove(ov_id[i]); if (ret != 0) { unittest(0, "overlay @"%s" not destroyed @"%s"\n", overlay_path(overlay_nr + i), @@ -2151,9 +2151,9 @@ static int __init overlay_data_add(int onum) goto out_free_np_overlay; }

- ret = of_overlay_create(info->np_overlay); + ret = of_overlay_apply(info->np_overlay); if (ret < 0) { - pr_err("of_overlay_create() (ret=%d), %d\n", ret, onum); + pr_err("of_overlay_apply() (ret=%d), %d\n", ret, onum); goto out_free_np_overlay; } else { info->overlay_id = ret; diff --git a/include/linux/of.h b/include/linux/of.h index cfc34117fc92..45e787e28ce7 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -1306,26 +1306,26 @@ struct of_overlay_notify_data { #ifdef CONFIG_OF_OVERLAY

/* ID based overlays; the API for external users */ -int of_overlay_create(struct device_node *tree); -int of_overlay_destroy(int id); -int of_overlay_destroy_all(void); +int of_overlay_apply(struct device_node *tree); +int of_overlay_remove(int id); +int of_overlay_remove_all(void);

int of_overlay_notifier_register(struct notifier_block *nb); int of_overlay_notifier_unregister(struct notifier_block *nb);

#else

-static inline int of_overlay_create(struct device_node *tree) +static inline int of_overlay_apply(struct device_node *tree) { return -ENOTSUPP; }

-static inline int of_overlay_destroy(int id) +static inline int of_overlay_remove(int id) { return -ENOTSUPP; }

-static inline int of_overlay_destroy_all(void) +static inline int of_overlay_remove_all(void) { return -ENOTSUPP; }

From: Frank Rowand frank.rowand@sony.com

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 frank.rowand@sony.com --- drivers/of/overlay.c | 205 +++++++++++++++++++++++---------------------------- 1 file changed, 92 insertions(+), 113 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index c350742ed2a2..0f92a5c26748 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -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) @@ -160,8 +163,6 @@ static struct property *dup_and_fixup_symbol_prop( kfree(new->value); kfree(new); return NULL; - - }

/** @@ -249,13 +250,7 @@ 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) @@ -267,11 +262,15 @@ 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; }

@@ -385,41 +384,6 @@ static struct device_node *find_target_node(struct device_node *info_node) }

/** - * 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 of_overlay *ov, - struct device_node *info_node, struct of_overlay_info *ovinfo) -{ - ovinfo->overlay = of_get_child_by_name(info_node, "__overlay__"); - if (!ovinfo->overlay) - goto err_fail; - - ovinfo->target = find_target_node(info_node); - if (!ovinfo->target) - goto err_fail; - - return 0; - -err_fail: - of_node_put(ovinfo->target); - of_node_put(ovinfo->overlay); - - memset(ovinfo, 0, sizeof(*ovinfo)); - return -EINVAL; -} - -/** * init_overlay_changeset() - initialize overlay changeset from overlay tree * @ovcs Overlay changeset to build * @tree: Contains all the overlay fragments and overlay fixup nodes @@ -429,32 +393,61 @@ static int of_fill_overlay_info(struct of_overlay *ov, * 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__"); @@ -466,44 +459,51 @@ 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 @@ -517,47 +517,34 @@ static void free_overlay_fragments(struct overlay_changeset *ovcs) 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);

@@ -565,15 +552,11 @@ int of_overlay_apply(struct device_node *tree)

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; @@ -684,13 +667,14 @@ 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); @@ -709,20 +693,15 @@ int of_overlay_remove(int ovcs_id) 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);

From: Frank Rowand frank.rowand@sony.com

The test of whether it is safe to remove an overlay changeset looked at whether any node in the overlay changeset was in a subtree rooted at any more recently applied overlay changeset node.

The test failed to determine whether any node in the overlay changeset was the root of a subtree that contained a more recently applied overlay changeset node. Add this additional check to the test.

The test is still lacking any check for any phandle dependencies.

Signed-off-by: Frank Rowand frank.rowand@sony.com --- drivers/of/overlay.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index c7526186b1c8..015d8b112f60 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -698,13 +698,13 @@ static int find_node(struct device_node *tree, struct device_node *np) }

/* - * Is @remove_ce_np a child of or the same as any + * Is @remove_ce_node a child of, a parent of, or the same as any * node in an overlay changeset more topmost than @remove_ovcs? * * Returns 1 if found, else 0 */ -static int node_in_later_cs(struct overlay_changeset *remove_ovcs, - struct device_node *remove_ce_np) +static int node_overlaps_later_cs(struct overlay_changeset *remove_ovcs, + struct device_node *remove_ce_node) { struct overlay_changeset *ovcs; struct of_changeset_entry *ce; @@ -714,10 +714,16 @@ static int node_in_later_cs(struct overlay_changeset *remove_ovcs, break;

list_for_each_entry(ce, &ovcs->cset.entries, node) { - if (find_node(ce->np, remove_ce_np)) { - pr_err("%s: #%d clashes #%d @%pOF\n", + if (find_node(ce->np, remove_ce_node)) { + pr_err("%s: #%d overlaps with #%d @%pOF\n", __func__, remove_ovcs->id, ovcs->id, - remove_ce_np); + remove_ce_node); + return 1; + } + if (find_node(remove_ce_node, ce->np)) { + pr_err("%s: #%d overlaps with #%d @%pOF\n", + __func__, remove_ovcs->id, ovcs->id, + remove_ce_node); return 1; } } @@ -741,7 +747,7 @@ static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs) struct of_changeset_entry *remove_ce;

list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) { - if (node_in_later_cs(remove_ovcs, remove_ce->np)) { + if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) { pr_err("overlay #%d is not topmost\n", remove_ovcs->id); return 0; }

From: Frank Rowand frank.rowand@sony.com

The process of applying an overlay consists of: - unflatten an overlay FDT (flattened device tree) into an EDT (expanded device tree) - fixup the phandle values in the overlay EDT to fit in a range above the phandle values in the live device tree - create the overlay changeset to reflect the contents of the overlay EDT - apply the overlay changeset, to modify the live device tree, potentially changing the maximum phandle value in the live device tree

There is currently no protection against two overlay applies concurrently determining what range of phandle values are in use in the live device tree, and subsequently changing that range. Add a mutex to prevent multiple overlay applies from occurring simultaneously.

Ignoring 2 checkpatch warnings: Prefer using '"%s...", __func__' so that the WARN() string will be more easily grepped.

Signed-off-by: Frank Rowand frank.rowand@sony.com --- drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c | 7 +++++++ drivers/of/overlay.c | 22 ++++++++++++++++++++++ drivers/of/unittest.c | 21 +++++++++++++++++++++ include/linux/of.h | 19 +++++++++++++++++++ 4 files changed, 69 insertions(+)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c index 7a7be0515bfd..c99f7924b1c6 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c @@ -221,6 +221,11 @@ static void __init tilcdc_convert_slave_node(void) goto out; }

+ /* + * protect from of_resolve_phandles() through of_overlay_apply() + */ + of_overlay_mutex_lock(); + overlay = tilcdc_get_overlay(&kft); if (!overlay) goto out; @@ -256,6 +261,8 @@ static void __init tilcdc_convert_slave_node(void) pr_info("%s: ti,tilcdc,slave node successfully converted\n", __func__); out: + of_overlay_mutex_unlock(); + kfree_table_free(&kft); of_node_put(i2c); of_node_put(slave); diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index a0d3222febdc..4ed372af6ce7 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -71,6 +71,28 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs, const struct device_node *overlay_node, bool is_symbols_node);

+/* + * of_resolve_phandles() finds the largest phandle in the live tree. + * of_overlay_apply() may add a larger phandle to the live tree. + * Do not allow race between two overlays being applied simultaneously: + * mutex_lock(&of_overlay_phandle_mutex) + * of_resolve_phandles() + * of_overlay_apply() + * mutex_unlock(&of_overlay_phandle_mutex) + */ +static DEFINE_MUTEX(of_overlay_phandle_mutex); + +void of_overlay_mutex_lock(void) +{ + mutex_lock(&of_overlay_phandle_mutex); +} + +void of_overlay_mutex_unlock(void) +{ + mutex_unlock(&of_overlay_phandle_mutex); +} + + static LIST_HEAD(ovcs_list); static DEFINE_IDR(ovcs_idr);

diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index db2f170186de..f4c8aff21320 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -994,9 +994,17 @@ static int __init unittest_data_add(void) return -ENODATA; } of_node_set_flag(unittest_data_node, OF_DETACHED); + + /* + * This lock normally encloses of_overlay_apply() as well as + * of_resolve_phandles(). + */ + of_overlay_mutex_lock(); + rc = of_resolve_phandles(unittest_data_node); if (rc) { pr_err("%s: Failed to resolve phandles (rc=%i)\n", __func__, rc); + of_overlay_mutex_unlock(); return -EINVAL; }

@@ -1006,6 +1014,7 @@ static int __init unittest_data_add(void) __of_attach_node_sysfs(np); of_aliases = of_find_node_by_path("/aliases"); of_chosen = of_find_node_by_path("/chosen"); + of_overlay_mutex_unlock(); return 0; }

@@ -1018,6 +1027,9 @@ static int __init unittest_data_add(void) attach_node_and_children(np); np = next; } + + of_overlay_mutex_unlock(); + return 0; }

@@ -2150,9 +2162,12 @@ static int __init overlay_data_add(int onum) } of_node_set_flag(info->np_overlay, OF_DETACHED);

+ of_overlay_mutex_lock(); + ret = of_resolve_phandles(info->np_overlay); if (ret) { pr_err("resolve ot phandles (ret=%d), %d\n", ret, onum); + of_overlay_mutex_unlock(); goto out_free_np_overlay; }

@@ -2160,9 +2175,12 @@ static int __init overlay_data_add(int onum) ret = of_overlay_apply(info->np_overlay, &info->overlay_id); if (ret < 0) { pr_err("of_overlay_apply() (ret=%d), %d\n", ret, onum); + of_overlay_mutex_unlock(); goto out_free_np_overlay; }

+ of_overlay_mutex_unlock(); + pr_debug("__dtb_overlay_begin applied, overlay id %d\n", ret);

goto out; @@ -2209,7 +2227,10 @@ static __init void of_unittest_overlay_high_level(void) * Could not fixup phandles in unittest_unflatten_overlay_base() * because kmalloc() was not yet available. */ + of_overlay_mutex_lock(); of_resolve_phandles(overlay_base_root); + of_overlay_mutex_unlock(); +

/* * do not allow overlay_base to duplicate any node already in diff --git a/include/linux/of.h b/include/linux/of.h index 49e5f24fb390..eb60eddf83c2 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -1306,6 +1306,9 @@ struct of_overlay_notify_data { #ifdef CONFIG_OF_OVERLAY

/* ID based overlays; the API for external users */ +void of_overlay_mutex_lock(void); +void of_overlay_mutex_unlock(void); + int of_overlay_apply(struct device_node *tree, int *ovcs_id); int of_overlay_remove(int *ovcs_id); int of_overlay_remove_all(void); @@ -1315,6 +1318,22 @@ struct of_overlay_notify_data {

#else

+static inline void of_overlay_mutex_lock(void) +{ +#ifndef CONFIG_OF_RESOLVE + /* avoid warning in unittest.c */ + WARN(1, "of_overlay_mutex_lock() ifdef'ed out\n"); +#endif +} + +static inline void of_overlay_mutex_unlock(void) +{ +#ifndef CONFIG_OF_RESOLVE + /* avoid warning in unittest.c */ + WARN(1, "of_overlay_mutex_unlock() ifdef'ed out\n"); +#endif +} + static inline int of_overlay_apply(struct device_node *tree, int *ovcs_id) { return -ENOTSUPP;

From: Frank Rowand frank.rowand@sony.com

The code to apply symbols from an overlay to the live device tree was implemented with the intent to be minimally intrusive on the existing code. After recent restructuring of the overlay apply code, it is easier to disintangle the code that applies the symbols, and to make the overlay changeset creation code more straight forward and understandable.

Remove the extra complexity, and make the code more obvious.

Signed-off-by: Frank Rowand frank.rowand@sony.com --- drivers/of/overlay.c | 91 +++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 65 insertions(+), 26 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 4ed372af6ce7..172807d3f375 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -32,21 +32,22 @@ struct fragment { struct device_node *target; struct device_node *overlay; - bool is_symbols_node; };

/** * struct overlay_changeset - * @ovcs_list: list on which we are located - * @count: count of @fragments structures - * @fragments: info about fragment nodes in overlay expanded device tree - * @cset: changeset to apply fragments to live device tree + * @ovcs_list: list on which we are located + * @count: count of fragment structures + * @fragments: fragment nodes in the overlay expanded device tree + * @symbols_fragment: last element of @fragments[] is the __symbols__ node + * @cset: changeset to apply fragments to live device tree */ struct overlay_changeset { int id; struct list_head ovcs_list; int count; struct fragment *fragments; + bool symbols_fragment; struct of_changeset cset; };

@@ -68,8 +69,7 @@ static int devicetree_corrupt(void)

static int build_changeset_next_level(struct overlay_changeset *ovcs, struct device_node *target_node, - const struct device_node *overlay_node, - bool is_symbols_node); + const struct device_node *overlay_node);

/* * of_resolve_phandles() finds the largest phandle in the live tree. @@ -221,7 +221,7 @@ static struct property *dup_and_fixup_symbol_prop( * @ovcs: overlay changeset * @target_node: where to place @overlay_prop in live tree * @overlay_prop: property to add or update, from overlay tree - * is_symbols_node: 1 if @target_node is "/__symbols__" + * @is_symbols_prop: 1 if @overlay_prop is from node "/__symbols__" * * If @overlay_prop does not already exist in @target_node, add changeset entry * to add @overlay_prop in @target_node, else add changeset entry to update @@ -237,7 +237,7 @@ static struct property *dup_and_fixup_symbol_prop( static int add_changeset_property(struct overlay_changeset *ovcs, struct device_node *target_node, struct property *overlay_prop, - bool is_symbols_node) + bool is_symbols_prop) { struct property *new_prop = NULL, *prop;

@@ -248,7 +248,7 @@ static int add_changeset_property(struct overlay_changeset *ovcs, !of_prop_cmp(overlay_prop->name, "linux,phandle")) return 0;

- if (is_symbols_node) { + if (is_symbols_prop) { if (prop) return -EINVAL; new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop); @@ -321,13 +321,13 @@ static int add_changeset_node(struct overlay_changeset *ovcs, if (ret) return ret;

- return build_changeset_next_level(ovcs, tchild, node, 0); + return build_changeset_next_level(ovcs, tchild, node); }

if (node->phandle && tchild->phandle) ret = -EINVAL; else - ret = build_changeset_next_level(ovcs, tchild, node, 0); + ret = build_changeset_next_level(ovcs, tchild, node); of_node_put(tchild);

return ret; @@ -338,7 +338,6 @@ static int add_changeset_node(struct overlay_changeset *ovcs, * @ovcs: overlay changeset * @target_node: where to place @overlay_node in live tree * @overlay_node: node from within an overlay device tree fragment - * @is_symbols_node: @overlay_node is node "/__symbols__" * * Add the properties (if any) and nodes (if any) from @overlay_node to the * @ovcs->cset changeset. If an added node has child nodes, they will @@ -351,16 +350,14 @@ static int add_changeset_node(struct overlay_changeset *ovcs, */ static int build_changeset_next_level(struct overlay_changeset *ovcs, struct device_node *target_node, - const struct device_node *overlay_node, - bool is_symbols_node) + const struct device_node *overlay_node) { struct device_node *child; struct property *prop; int ret;

for_each_property_of_node(overlay_node, prop) { - ret = add_changeset_property(ovcs, target_node, prop, - is_symbols_node); + ret = add_changeset_property(ovcs, target_node, prop, 0); if (ret) { pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", target_node, prop->name, ret); @@ -368,9 +365,6 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs, } }

- if (is_symbols_node) - return 0; - for_each_child_of_node(overlay_node, child) { ret = add_changeset_node(ovcs, target_node, child); if (ret) { @@ -384,6 +378,28 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs, return 0; }

+/* + * Add the properties from __overlay__ node to the @ovcs->cset changeset. + */ +static int build_changeset_symbols_node(struct overlay_changeset *ovcs, + struct device_node *target_node, + const struct device_node *overlay_symbols_node) +{ + struct property *prop; + int ret; + + for_each_property_of_node(overlay_symbols_node, prop) { + ret = add_changeset_property(ovcs, target_node, prop, 1); + if (ret) { + pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", + target_node, prop->name, ret); + return ret; + } + } + + return 0; +} + /** * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments * @ovcs: Overlay changeset @@ -398,14 +414,33 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs, */ static int build_changeset(struct overlay_changeset *ovcs) { - int i, ret; + struct fragment *fragment; + int fragments_count, i, ret;

- for (i = 0; i < ovcs->count; i++) { - struct fragment *fragment = &ovcs->fragments[i]; + /* + * if there is a symbols fragment in ovcs->fragments[i] it is + * the final element in the array + */ + if (ovcs->symbols_fragment) + fragments_count = ovcs->count - 1; + else + fragments_count = ovcs->count; + + for (i = 0; i < fragments_count; i++) { + fragment = &ovcs->fragments[i];

ret = build_changeset_next_level(ovcs, fragment->target, - fragment->overlay, - fragment->is_symbols_node); + fragment->overlay); + if (ret) { + pr_debug("apply failed '%pOF'\n", fragment->target); + return ret; + } + } + + if (ovcs->symbols_fragment) { + fragment = &ovcs->fragments[ovcs->count - 1]; + ret = build_changeset_symbols_node(ovcs, fragment->target, + fragment->overlay); if (ret) { pr_debug("apply failed '%pOF'\n", fragment->target); return ret; @@ -522,12 +557,16 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs, } }

+ /* + * if there is a symbols fragment in ovcs->fragments[i] it is + * the final element in the array + */ node = of_get_child_by_name(tree, "__symbols__"); if (node) { + ovcs->symbols_fragment = 1; fragment = &fragments[cnt]; fragment->overlay = node; fragment->target = of_find_node_by_path("/__symbols__"); - fragment->is_symbols_node = 1;

if (!fragment->target) { pr_err("no symbols in root of device tree.\n");

From: Frank Rowand frank.rowand@sony.com

kbasename() will not return NULL if passed a valid string. If the parameter passed to kbasename() in this case is already NULL then the devicetree has been corrupted.

Signed-off-by: Frank Rowand frank.rowand@sony.com --- drivers/of/overlay.c | 2 -- 1 file changed, 2 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 81881e45f273..88df2986b03f 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -322,8 +322,6 @@ static int add_changeset_node(struct overlay_changeset *ovcs, int ret = 0;

node_kbasename = kbasename(node->full_name); - if (!node_kbasename) - return -ENOMEM;

for_each_child_of_node(target_node, tchild) if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))