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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/of/resolver.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/of/resolver.c')
| -rw-r--r-- | drivers/of/resolver.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c new file mode 100644 index 000000000..86424e145 --- /dev/null +++ b/drivers/of/resolver.c @@ -0,0 +1,325 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Functions for dealing with DT resolution + * + * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> + * Copyright (C) 2012 Texas Instruments Inc. + */ + +#define pr_fmt(fmt) "OF: resolver: " fmt + +#include <linux/cleanup.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/errno.h> +#include <linux/slab.h> + +#include "of_private.h" + +static phandle live_tree_max_phandle(void) +{ + struct device_node *node; + phandle phandle; + unsigned long flags; + + raw_spin_lock_irqsave(&devtree_lock, flags); + phandle = 0; + for_each_of_allnodes(node) { + if (node->phandle != OF_PHANDLE_ILLEGAL && + node->phandle > phandle) + phandle = node->phandle; + } + raw_spin_unlock_irqrestore(&devtree_lock, flags); + + return phandle; +} + +static void adjust_overlay_phandles(struct device_node *overlay, + int phandle_delta) +{ + struct device_node *child; + const struct property *prop; + phandle phandle; + + /* adjust node's phandle in node */ + if (overlay->phandle != 0 && overlay->phandle != OF_PHANDLE_ILLEGAL) + overlay->phandle += phandle_delta; + + /* copy adjusted phandle into *phandle properties */ + for_each_property_of_node(overlay, prop) { + + if (of_prop_cmp(prop->name, "phandle") && + of_prop_cmp(prop->name, "linux,phandle")) + continue; + + if (prop->length < 4) + continue; + + phandle = be32_to_cpup(prop->value); + if (phandle == OF_PHANDLE_ILLEGAL) + continue; + + *(__be32 *)prop->value = cpu_to_be32(overlay->phandle); + } + + for_each_child_of_node(overlay, child) + adjust_overlay_phandles(child, phandle_delta); +} + +static int update_usages_of_a_phandle_reference(struct device_node *overlay, + const struct property *prop_fixup, phandle phandle) +{ + struct device_node *refnode; + const struct property *prop; + char *value __free(kfree) = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL); + char *cur, *end, *node_path, *prop_name, *s; + int offset, len; + int err = 0; + + if (!value) + return -ENOMEM; + + /* prop_fixup contains a list of tuples of path:property_name:offset */ + end = value + prop_fixup->length; + for (cur = value; cur < end; cur += len + 1) { + len = strlen(cur); + + node_path = cur; + s = strchr(cur, ':'); + if (!s) + return -EINVAL; + *s++ = '\0'; + + prop_name = s; + s = strchr(s, ':'); + if (!s) + return -EINVAL; + *s++ = '\0'; + + err = kstrtoint(s, 10, &offset); + if (err) + return err; + + refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path); + if (!refnode) + continue; + + for_each_property_of_node(refnode, prop) { + if (!of_prop_cmp(prop->name, prop_name)) + break; + } + of_node_put(refnode); + + if (!prop) + return -ENOENT; + + if (offset < 0 || offset + sizeof(__be32) > prop->length) + return -EINVAL; + + *(__be32 *)(prop->value + offset) = cpu_to_be32(phandle); + } + + return 0; +} + +/* compare nodes taking into account that 'name' strips out the @ part */ +static int node_name_cmp(const struct device_node *dn1, + const struct device_node *dn2) +{ + const char *n1 = kbasename(dn1->full_name); + const char *n2 = kbasename(dn2->full_name); + + return of_node_cmp(n1, n2); +} + +/* + * Adjust the local phandle references by the given phandle delta. + * + * Subtree @local_fixups, which is overlay node __local_fixups__, + * mirrors the fragment node structure at the root of the overlay. + * + * For each property in the fragments that contains a phandle reference, + * @local_fixups has a property of the same name that contains a list + * of offsets of the phandle reference(s) within the respective property + * value(s). The values at these offsets will be fixed up. + */ +static int adjust_local_phandle_references(const struct device_node *local_fixups, + const struct device_node *overlay, int phandle_delta) +{ + struct device_node *overlay_child; + const struct property *prop_fix, *prop; + int err, i, count; + unsigned int off; + + if (!local_fixups) + return 0; + + for_each_property_of_node(local_fixups, prop_fix) { + + /* skip properties added automatically */ + if (is_pseudo_property(prop_fix->name)) + continue; + + if ((prop_fix->length % 4) != 0 || prop_fix->length == 0) + return -EINVAL; + count = prop_fix->length / sizeof(__be32); + + for_each_property_of_node(overlay, prop) { + if (!of_prop_cmp(prop->name, prop_fix->name)) + break; + } + + if (!prop) + return -EINVAL; + + for (i = 0; i < count; i++) { + off = be32_to_cpu(((__be32 *)prop_fix->value)[i]); + if ((off + 4) > prop->length) + return -EINVAL; + + be32_add_cpu(prop->value + off, phandle_delta); + } + } + + /* + * These nested loops recurse down two subtrees in parallel, where the + * node names in the two subtrees match. + * + * The roots of the subtrees are the overlay's __local_fixups__ node + * and the overlay's root node. + */ + for_each_child_of_node_scoped(local_fixups, child) { + + for_each_child_of_node(overlay, overlay_child) + if (!node_name_cmp(child, overlay_child)) { + of_node_put(overlay_child); + break; + } + + if (!overlay_child) + return -EINVAL; + + err = adjust_local_phandle_references(child, overlay_child, + phandle_delta); + if (err) + return err; + } + + return 0; +} + +/** + * of_resolve_phandles - Relocate and resolve overlay against live tree + * + * @overlay: Pointer to devicetree overlay to relocate and resolve + * + * Modify (relocate) values of local phandles in @overlay to a range that + * does not conflict with the live expanded devicetree. Update references + * to the local phandles in @overlay. Update (resolve) phandle references + * in @overlay that refer to the live expanded devicetree. + * + * Phandle values in the live tree are in the range of + * 1 .. live_tree_max_phandle(). The range of phandle values in the overlay + * also begin with at 1. Adjust the phandle values in the overlay to begin + * at live_tree_max_phandle() + 1. Update references to the phandles to + * the adjusted phandle values. + * + * The name of each property in the "__fixups__" node in the overlay matches + * the name of a symbol (a label) in the live tree. The values of each + * property in the "__fixups__" node is a list of the property values in the + * overlay that need to be updated to contain the phandle reference + * corresponding to that symbol in the live tree. Update the references in + * the overlay with the phandle values in the live tree. + * + * @overlay must be detached. + * + * Resolving and applying @overlay to the live expanded devicetree must be + * protected by a mechanism to ensure that multiple overlays are processed + * in a single threaded manner so that multiple overlays will not relocate + * phandles to overlapping ranges. The mechanism to enforce this is not + * yet implemented. + * + * Return: %0 on success or a negative error value on error. + */ +int of_resolve_phandles(struct device_node *overlay) +{ + struct device_node *child, *refnode; + struct device_node *overlay_fixups; + struct device_node __free(device_node) *local_fixups = NULL; + struct property *prop; + const char *refpath; + phandle phandle, phandle_delta; + int err; + + if (!overlay) { + pr_err("null overlay\n"); + return -EINVAL; + } + + if (!of_node_check_flag(overlay, OF_DETACHED)) { + pr_err("overlay not detached\n"); + return -EINVAL; + } + + phandle_delta = live_tree_max_phandle() + 1; + adjust_overlay_phandles(overlay, phandle_delta); + + for_each_child_of_node(overlay, local_fixups) + if (of_node_name_eq(local_fixups, "__local_fixups__")) + break; + + err = adjust_local_phandle_references(local_fixups, overlay, phandle_delta); + if (err) + return err; + + overlay_fixups = NULL; + + for_each_child_of_node(overlay, child) { + if (of_node_name_eq(child, "__fixups__")) + overlay_fixups = child; + } + + if (!overlay_fixups) + return 0; + + struct device_node __free(device_node) *tree_symbols = of_find_node_by_path("/__symbols__"); + if (!tree_symbols) { + pr_err("no symbols in root of device tree.\n"); + return -EINVAL; + } + + for_each_property_of_node(overlay_fixups, prop) { + + /* skip properties added automatically */ + if (!of_prop_cmp(prop->name, "name")) + continue; + + err = of_property_read_string(tree_symbols, + prop->name, &refpath); + if (err) { + pr_err("node label '%s' not found in live devicetree symbols table\n", + prop->name); + return err; + } + + refnode = of_find_node_by_path(refpath); + if (!refnode) + return -ENOENT; + + phandle = refnode->phandle; + of_node_put(refnode); + + err = update_usages_of_a_phandle_reference(overlay, prop, phandle); + if (err) + break; + } + + if (err) + pr_err("overlay phandle fixup failed: %d\n", err); + return err; +} +EXPORT_SYMBOL_GPL(of_resolve_phandles); |
