From a9e3760b0838299649c0d57cca44daaf40ba3c33 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2026 22:12:34 -1000 Subject: sched_ext: Maintain an online cid mask in the scheduler arena Schedulers on the default cid mapping treat [0, nr_online_cids) as the online set and restart on hotplug. Schedulers that install their own mapping with scx_bpf_cid_override() have no way to learn which cids are online: the count no longer identifies members and the CPU-form cpumask is unusable from cid programs. This is an obvious hole in the cid API. Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's arena, allocated alongside the per-CPU scratch masks and populated after the cid mapping is finalized and before ops.init(), for child schedulers too. The pointer stays valid through ops.exit() with no reference to take. It is the arena offset as a void pointer, the same form struct_ops arena arguments arrive in. The verifier types the void return as a scalar for the program's arena cast. The mask follows the SCX hotplug notifications: seeded from cpu_active_mask and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask only inside a hotplug transition. Updates walk the scheduler list under the lock that also serializes unlinking. Reads are live, not atomic snapshots. Root initialization excludes hotplug. v2: Reworded the getter kerneldoc (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- drivers/pinctrl/devicetree.c | 439 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 439 insertions(+) create mode 100644 drivers/pinctrl/devicetree.c (limited to 'drivers/pinctrl/devicetree.c') diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c new file mode 100644 index 000000000..465b43092 --- /dev/null +++ b/drivers/pinctrl/devicetree.c @@ -0,0 +1,439 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Device tree integration for the pin control subsystem + * + * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved. + */ + +#include +#include +#include +#include + +#include "core.h" +#include "devicetree.h" + +/** + * struct pinctrl_dt_map - mapping table chunk parsed from device tree + * @node: list node for struct pinctrl's @dt_maps field + * @pctldev: the pin controller that allocated this struct, and will free it + * @map: the mapping table entries + * @num_maps: number of mapping table entries + */ +struct pinctrl_dt_map { + struct list_head node; + struct pinctrl_dev *pctldev; + struct pinctrl_map *map; + unsigned int num_maps; +}; + +static void dt_free_map(struct pinctrl_dev *pctldev, + struct pinctrl_map *map, unsigned int num_maps) +{ + int i; + + for (i = 0; i < num_maps; ++i) { + kfree_const(map[i].dev_name); + map[i].dev_name = NULL; + } + + if (pctldev) { + const struct pinctrl_ops *ops = pctldev->desc->pctlops; + if (ops->dt_free_map) + ops->dt_free_map(pctldev, map, num_maps); + } else { + /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ + kfree(map); + } +} + +void pinctrl_dt_free_maps(struct pinctrl *p) +{ + struct pinctrl_dt_map *dt_map, *n1; + + list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) { + pinctrl_unregister_mappings(dt_map->map); + list_del(&dt_map->node); + dt_free_map(dt_map->pctldev, dt_map->map, + dt_map->num_maps); + kfree(dt_map); + } + + of_node_put(p->dev->of_node); +} + +static int dt_remember_or_free_map(struct pinctrl *p, const char *statename, + struct pinctrl_dev *pctldev, + struct pinctrl_map *map, unsigned int num_maps) +{ + int i; + struct pinctrl_dt_map *dt_map; + + /* Initialize dev_name before any allocation can fail */ + for (i = 0; i < num_maps; i++) + map[i].dev_name = NULL; + + /* Initialize common mapping table entry fields */ + for (i = 0; i < num_maps; i++) { + const char *devname; + + devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL); + if (!devname) + goto err_free_map; + + map[i].dev_name = devname; + map[i].name = statename; + if (pctldev) + map[i].ctrl_dev_name = dev_name(pctldev->dev); + } + + /* Remember the converted mapping table entries */ + dt_map = kzalloc_obj(*dt_map); + if (!dt_map) + goto err_free_map; + + dt_map->pctldev = pctldev; + dt_map->map = map; + dt_map->num_maps = num_maps; + list_add_tail(&dt_map->node, &p->dt_maps); + + return pinctrl_register_mappings(map, num_maps); + +err_free_map: + dt_free_map(pctldev, map, num_maps); + return -ENOMEM; +} + +struct pinctrl_dev *of_pinctrl_get(struct device_node *np) +{ + return get_pinctrl_dev_from_of_node(np); +} +EXPORT_SYMBOL_GPL(of_pinctrl_get); + +static int dt_to_map_one_config(struct pinctrl *p, + struct pinctrl_dev *hog_pctldev, + const char *statename, + struct device_node *np_config) +{ + struct pinctrl_dev *pctldev = NULL; + struct device_node *np_pctldev; + const struct pinctrl_ops *ops; + int ret; + struct pinctrl_map *map; + unsigned int num_maps; + bool allow_default = false; + + /* Find the pin controller containing np_config */ + np_pctldev = of_node_get(np_config); + for (;;) { + if (!allow_default) + allow_default = of_property_read_bool(np_pctldev, + "pinctrl-use-default"); + + np_pctldev = of_get_next_parent(np_pctldev); + if (!np_pctldev || of_node_is_root(np_pctldev)) { + of_node_put(np_pctldev); + ret = -ENODEV; + /* keep deferring if modules are enabled */ + if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0) + ret = -EPROBE_DEFER; + return ret; + } + /* If we're creating a hog we can use the passed pctldev */ + if (hog_pctldev && (np_pctldev == p->dev->of_node)) { + pctldev = hog_pctldev; + break; + } + pctldev = get_pinctrl_dev_from_of_node(np_pctldev); + if (pctldev) + break; + /* + * Do not defer probing of hogs (circular loop) + * + * Return 1 to let the caller catch the case. + */ + if (np_pctldev == p->dev->of_node) { + of_node_put(np_pctldev); + return 1; + } + } + of_node_put(np_pctldev); + + /* + * Call pinctrl driver to parse device tree node, and + * generate mapping table entries + */ + ops = pctldev->desc->pctlops; + if (!ops->dt_node_to_map) { + dev_err(p->dev, "pctldev %s doesn't support DT\n", + dev_name(pctldev->dev)); + return -ENODEV; + } + ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); + if (ret < 0) + return ret; + else if (num_maps == 0) { + /* + * If we have no valid maps (maybe caused by empty pinctrl node + * or typing error) ther is no need remember this, so just + * return. + */ + dev_info(p->dev, + "there are no valid maps for state %s\n", statename); + return 0; + } + + /* Stash the mapping table chunk away for later use */ + return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); +} + +static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) +{ + struct pinctrl_map *map; + + map = kzalloc_obj(*map); + if (!map) + return -ENOMEM; + + /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ + map->type = PIN_MAP_TYPE_DUMMY_STATE; + + return dt_remember_or_free_map(p, statename, NULL, map, 1); +} + +int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev) +{ + struct device_node *np = p->dev->of_node; + int state, ret; + char *propname; + struct property *prop; + const char *statename; + const __be32 *list; + int size, config; + phandle phandle; + struct device_node *np_config; + + /* CONFIG_OF enabled, p->dev not instantiated from DT */ + if (!np) { + if (of_have_populated_dt()) + dev_dbg(p->dev, + "no of_node; not parsing pinctrl DT\n"); + return 0; + } + + /* We may store pointers to property names within the node */ + of_node_get(np); + + /* For each defined state ID */ + for (state = 0; ; state++) { + /* Retrieve the pinctrl-* property */ + propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); + if (!propname) { + ret = -ENOMEM; + goto err; + } + prop = of_find_property(np, propname, &size); + kfree(propname); + if (!prop) { + if (state == 0) { + ret = -ENODEV; + goto err; + } + break; + } + list = prop->value; + size /= sizeof(*list); + + /* Determine whether pinctrl-names property names the state */ + ret = of_property_read_string_index(np, "pinctrl-names", + state, &statename); + /* + * If not, statename is just the integer state ID. But rather + * than dynamically allocate it and have to free it later, + * just point part way into the property name for the string. + */ + if (ret < 0) + statename = prop->name + strlen("pinctrl-"); + + /* For every referenced pin configuration node in it */ + for (config = 0; config < size; config++) { + phandle = be32_to_cpup(list++); + + /* Look up the pin configuration node */ + np_config = of_find_node_by_phandle(phandle); + if (!np_config) { + dev_err(p->dev, + "prop %s index %i invalid phandle\n", + prop->name, config); + ret = -EINVAL; + goto err; + } + + /* Parse the node */ + ret = dt_to_map_one_config(p, pctldev, statename, + np_config); + of_node_put(np_config); + if (ret == 1) + continue; + if (ret < 0) + goto err; + } + + /* No entries in DT? Generate a dummy state table entry */ + if (!size) { + ret = dt_remember_dummy_state(p, statename); + if (ret < 0) + goto err; + } + } + + return 0; + +err: + pinctrl_dt_free_maps(p); + return ret; +} + +/* + * For pinctrl binding, typically #pinctrl-cells is for the pin controller + * device, so either parent or grandparent. See pinctrl-bindings.txt. + */ +static int pinctrl_find_cells_size(const struct device_node *np) +{ + const char *cells_name = "#pinctrl-cells"; + int cells_size, error; + + error = of_property_read_u32(np->parent, cells_name, &cells_size); + if (error) { + error = of_property_read_u32(np->parent->parent, + cells_name, &cells_size); + if (error) + return -ENOENT; + } + + return cells_size; +} + +/** + * pinctrl_get_list_and_count - Gets the list and it's cell size and number + * @np: pointer to device node with the property + * @list_name: property that contains the list + * @list: pointer for the list found + * @cells_size: pointer for the cell size found + * @nr_elements: pointer for the number of elements found + * + * Typically np is a single pinctrl entry containing the list. + */ +static int pinctrl_get_list_and_count(const struct device_node *np, + const char *list_name, + const __be32 **list, + int *cells_size, + int *nr_elements) +{ + int size; + + *cells_size = 0; + *nr_elements = 0; + + *list = of_get_property(np, list_name, &size); + if (!*list) + return -ENOENT; + + *cells_size = pinctrl_find_cells_size(np); + if (*cells_size < 0) + return -ENOENT; + + /* First element is always the index within the pinctrl device */ + *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); + + return 0; +} + +/** + * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry + * @np: pointer to device node with the property + * @list_name: property that contains the list + * + * Counts the number of elements in a pinctrl array consisting of an index + * within the controller and a number of u32 entries specified for each + * entry. Note that device_node is always for the parent pin controller device. + */ +int pinctrl_count_index_with_args(const struct device_node *np, + const char *list_name) +{ + const __be32 *list; + int size, nr_cells, error; + + error = pinctrl_get_list_and_count(np, list_name, &list, + &nr_cells, &size); + if (error) + return error; + + return size; +} +EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); + +/** + * pinctrl_copy_args - Populates of_phandle_args based on index + * @np: pointer to device node with the property + * @list: pointer to a list with the elements + * @index: entry within the list of elements + * @nr_cells: number of cells in the list + * @nr_elem: number of elements for each entry in the list + * @out_args: returned values + * + * Populates the of_phandle_args based on the index in the list. + */ +static int pinctrl_copy_args(const struct device_node *np, + const __be32 *list, + int index, int nr_cells, int nr_elem, + struct of_phandle_args *out_args) +{ + int i; + + memset(out_args, 0, sizeof(*out_args)); + out_args->np = (struct device_node *)np; + out_args->args_count = nr_cells + 1; + + if (index >= nr_elem) + return -EINVAL; + + list += index * (nr_cells + 1); + + for (i = 0; i < nr_cells + 1; i++) + out_args->args[i] = be32_to_cpup(list++); + + return 0; +} + +/** + * pinctrl_parse_index_with_args - Find a node pointed by index in a list + * @np: pointer to device node with the property + * @list_name: property that contains the list + * @index: index within the list + * @out_args: entries in the list pointed by index + * + * Finds the selected element in a pinctrl array consisting of an index + * within the controller and a number of u32 entries specified for each + * entry. Note that device_node is always for the parent pin controller device. + */ +int pinctrl_parse_index_with_args(const struct device_node *np, + const char *list_name, int index, + struct of_phandle_args *out_args) +{ + const __be32 *list; + int nr_elem, nr_cells, error; + + error = pinctrl_get_list_and_count(np, list_name, &list, + &nr_cells, &nr_elem); + if (error || !nr_cells) + return error; + + error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, + out_args); + if (error) + return error; + + return 0; +} +EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); -- cgit v1.3.1