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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/firmware/google/vpd.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/firmware/google/vpd.c')
| -rw-r--r-- | drivers/firmware/google/vpd.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/drivers/firmware/google/vpd.c b/drivers/firmware/google/vpd.c new file mode 100644 index 000000000..fbb5a8d7c --- /dev/null +++ b/drivers/firmware/google/vpd.c @@ -0,0 +1,328 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vpd.c + * + * Driver for exporting VPD content to sysfs. + * + * Copyright 2017 Google Inc. + */ + +#include <linux/ctype.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/kobject.h> +#include <linux/list.h> +#include <linux/device-id/coreboot.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include "coreboot_table.h" +#include "vpd_decode.h" + +#define CB_TAG_VPD 0x2c +#define VPD_CBMEM_MAGIC 0x43524f53 + +static struct kobject *vpd_kobj; + +struct vpd_cbmem { + u32 magic; + u32 version; + u32 ro_size; + u32 rw_size; + u8 blob[]; +}; + +struct vpd_section { + bool enabled; + const char *name; + char *raw_name; /* the string name_raw */ + struct kobject *kobj; /* vpd/name directory */ + char *baseaddr; + struct bin_attribute bin_attr; /* vpd/name_raw bin_attribute */ + struct list_head attribs; /* key/value in vpd_attrib_info list */ +}; + +struct vpd_attrib_info { + char *key; + const char *value; + struct bin_attribute bin_attr; + struct list_head list; +}; + +static struct vpd_section ro_vpd; +static struct vpd_section rw_vpd; + +static ssize_t vpd_attrib_read(struct file *filp, struct kobject *kobp, + const struct bin_attribute *bin_attr, char *buf, + loff_t pos, size_t count) +{ + struct vpd_attrib_info *info = bin_attr->private; + + return memory_read_from_buffer(buf, count, &pos, info->value, + info->bin_attr.size); +} + +/* + * vpd_section_check_key_name() + * + * The VPD specification supports only [a-zA-Z0-9_]+ characters in key names but + * old firmware versions may have entries like "S/N" which are problematic when + * exporting them as sysfs attributes. These keys present in old firmwares are + * ignored. + * + * Returns VPD_OK for a valid key name, VPD_FAIL otherwise. + * + * @key: The key name to check + * @key_len: key name length + */ +static int vpd_section_check_key_name(const u8 *key, s32 key_len) +{ + int c; + + while (key_len-- > 0) { + c = *key++; + + if (!isalnum(c) && c != '_') + return VPD_FAIL; + } + + return VPD_OK; +} + +static int vpd_section_attrib_add(const u8 *key, u32 key_len, + const u8 *value, u32 value_len, + void *arg) +{ + int ret; + struct vpd_section *sec = arg; + struct vpd_attrib_info *info; + + /* + * Return VPD_OK immediately to decode next entry if the current key + * name contains invalid characters. + */ + if (vpd_section_check_key_name(key, key_len) != VPD_OK) + return VPD_OK; + + info = kzalloc_obj(*info); + if (!info) + return -ENOMEM; + + info->key = kstrndup(key, key_len, GFP_KERNEL); + if (!info->key) { + ret = -ENOMEM; + goto free_info; + } + + sysfs_bin_attr_init(&info->bin_attr); + info->bin_attr.attr.name = info->key; + info->bin_attr.attr.mode = 0444; + info->bin_attr.size = value_len; + info->bin_attr.read = vpd_attrib_read; + info->bin_attr.private = info; + + info->value = value; + + INIT_LIST_HEAD(&info->list); + + ret = sysfs_create_bin_file(sec->kobj, &info->bin_attr); + if (ret) + goto free_info_key; + + list_add_tail(&info->list, &sec->attribs); + return 0; + +free_info_key: + kfree(info->key); +free_info: + kfree(info); + + return ret; +} + +static void vpd_section_attrib_destroy(struct vpd_section *sec) +{ + struct vpd_attrib_info *info; + struct vpd_attrib_info *temp; + + list_for_each_entry_safe(info, temp, &sec->attribs, list) { + sysfs_remove_bin_file(sec->kobj, &info->bin_attr); + kfree(info->key); + kfree(info); + } +} + +static ssize_t vpd_section_read(struct file *filp, struct kobject *kobp, + const struct bin_attribute *bin_attr, char *buf, + loff_t pos, size_t count) +{ + struct vpd_section *sec = bin_attr->private; + + return memory_read_from_buffer(buf, count, &pos, sec->baseaddr, + sec->bin_attr.size); +} + +static int vpd_section_create_attribs(struct vpd_section *sec) +{ + s32 consumed; + int ret; + + consumed = 0; + do { + ret = vpd_decode_string(sec->bin_attr.size, sec->baseaddr, + &consumed, vpd_section_attrib_add, sec); + } while (ret == VPD_OK); + + return 0; +} + +static int vpd_section_init(const char *name, struct vpd_section *sec, + phys_addr_t physaddr, size_t size) +{ + int err; + + sec->baseaddr = memremap(physaddr, size, MEMREMAP_WB); + if (!sec->baseaddr) + return -ENOMEM; + + sec->name = name; + + /* We want to export the raw partition with name ${name}_raw */ + sec->raw_name = kasprintf(GFP_KERNEL, "%s_raw", name); + if (!sec->raw_name) { + err = -ENOMEM; + goto err_memunmap; + } + + sysfs_bin_attr_init(&sec->bin_attr); + sec->bin_attr.attr.name = sec->raw_name; + sec->bin_attr.attr.mode = 0444; + sec->bin_attr.size = size; + sec->bin_attr.read = vpd_section_read; + sec->bin_attr.private = sec; + + err = sysfs_create_bin_file(vpd_kobj, &sec->bin_attr); + if (err) + goto err_free_raw_name; + + sec->kobj = kobject_create_and_add(name, vpd_kobj); + if (!sec->kobj) { + err = -EINVAL; + goto err_sysfs_remove; + } + + INIT_LIST_HEAD(&sec->attribs); + vpd_section_create_attribs(sec); + + sec->enabled = true; + + return 0; + +err_sysfs_remove: + sysfs_remove_bin_file(vpd_kobj, &sec->bin_attr); +err_free_raw_name: + kfree(sec->raw_name); +err_memunmap: + memunmap(sec->baseaddr); + return err; +} + +static int vpd_section_destroy(struct vpd_section *sec) +{ + if (sec->enabled) { + vpd_section_attrib_destroy(sec); + kobject_put(sec->kobj); + sysfs_remove_bin_file(vpd_kobj, &sec->bin_attr); + kfree(sec->raw_name); + memunmap(sec->baseaddr); + sec->enabled = false; + } + + return 0; +} + +static int vpd_sections_init(phys_addr_t physaddr) +{ + struct vpd_cbmem *temp; + struct vpd_cbmem header; + int ret = 0; + + temp = memremap(physaddr, sizeof(struct vpd_cbmem), MEMREMAP_WB); + if (!temp) + return -ENOMEM; + + memcpy(&header, temp, sizeof(struct vpd_cbmem)); + memunmap(temp); + + if (header.magic != VPD_CBMEM_MAGIC) + return -ENODEV; + + if (header.ro_size) { + ret = vpd_section_init("ro", &ro_vpd, + physaddr + sizeof(struct vpd_cbmem), + header.ro_size); + if (ret) + return ret; + } + + if (header.rw_size) { + ret = vpd_section_init("rw", &rw_vpd, + physaddr + sizeof(struct vpd_cbmem) + + header.ro_size, header.rw_size); + if (ret) { + vpd_section_destroy(&ro_vpd); + return ret; + } + } + + return 0; +} + +static int vpd_probe(struct coreboot_device *dev) +{ + int ret; + + vpd_kobj = kobject_create_and_add("vpd", firmware_kobj); + if (!vpd_kobj) + return -ENOMEM; + + ret = vpd_sections_init(dev->cbmem_ref.cbmem_addr); + if (ret) { + kobject_put(vpd_kobj); + return ret; + } + + return 0; +} + +static void vpd_remove(struct coreboot_device *dev) +{ + vpd_section_destroy(&ro_vpd); + vpd_section_destroy(&rw_vpd); + + kobject_put(vpd_kobj); +} + +static const struct coreboot_device_id vpd_ids[] = { + { .tag = CB_TAG_VPD }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(coreboot, vpd_ids); + +static struct coreboot_driver vpd_driver = { + .probe = vpd_probe, + .remove = vpd_remove, + .drv = { + .name = "vpd", + }, + .id_table = vpd_ids, +}; +module_coreboot_driver(vpd_driver); + +MODULE_AUTHOR("Google, Inc."); +MODULE_DESCRIPTION("Driver for exporting Vital Product Data content to sysfs"); +MODULE_LICENSE("GPL"); |
