Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * dev-path-parser.c - EFI Device Path parser
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2016 Lukas Wunner <lukas@wunner.de>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * This program is free software; you can redistribute it and/or modify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * it under the terms of the GNU General Public License (version 2) as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * published by the Free Software Foundation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/acpi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/efi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/pci.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) struct acpi_hid_uid {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 	struct acpi_device_id hid[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 	char uid[11]; /* UINT_MAX + null byte */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) static int __init match_acpi_dev(struct device *dev, const void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	struct acpi_hid_uid hid_uid = *(const struct acpi_hid_uid *)data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	struct acpi_device *adev = to_acpi_device(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	if (acpi_match_device_ids(adev, hid_uid.hid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	if (adev->pnp.unique_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 		return !strcmp(adev->pnp.unique_id, hid_uid.uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 		return !strcmp("0", hid_uid.uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) static long __init parse_acpi_path(const struct efi_dev_path *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 				   struct device *parent, struct device **child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	struct acpi_hid_uid hid_uid = {};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	struct device *phys_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	if (node->header.length != 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	sprintf(hid_uid.hid[0].id, "%c%c%c%04X",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		'A' + ((node->acpi.hid >> 10) & 0x1f) - 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 		'A' + ((node->acpi.hid >>  5) & 0x1f) - 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		'A' + ((node->acpi.hid >>  0) & 0x1f) - 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 			node->acpi.hid >> 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	sprintf(hid_uid.uid, "%u", node->acpi.uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	*child = bus_find_device(&acpi_bus_type, NULL, &hid_uid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 				 match_acpi_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	if (!*child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	phys_dev = acpi_get_first_physical_node(to_acpi_device(*child));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	if (phys_dev) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 		get_device(phys_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 		put_device(*child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		*child = phys_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) static int __init match_pci_dev(struct device *dev, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	unsigned int devfn = *(unsigned int *)data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	return dev_is_pci(dev) && to_pci_dev(dev)->devfn == devfn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) static long __init parse_pci_path(const struct efi_dev_path *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 				  struct device *parent, struct device **child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	unsigned int devfn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	if (node->header.length != 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	if (!parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	devfn = PCI_DEVFN(node->pci.dev, node->pci.fn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	*child = device_find_child(parent, &devfn, match_pci_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	if (!*child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92)  * Insert parsers for further node types here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94)  * Each parser takes a pointer to the @node and to the @parent (will be NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95)  * for the first device path node). If a device corresponding to @node was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96)  * found below @parent, its reference count should be incremented and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97)  * device returned in @child.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99)  * The return value should be 0 on success or a negative int on failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)  * The special return values 0x01 (EFI_DEV_END_INSTANCE) and 0xFF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)  * (EFI_DEV_END_ENTIRE) signal the end of the device path, only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)  * parse_end_path() is supposed to return this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)  * Be sure to validate the node length and contents before commencing the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)  * search for a device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static long __init parse_end_path(const struct efi_dev_path *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 				  struct device *parent, struct device **child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	if (node->header.length != 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	if (node->header.sub_type != EFI_DEV_END_INSTANCE &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	    node->header.sub_type != EFI_DEV_END_ENTIRE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	if (!parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	*child = get_device(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	return node->header.sub_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)  * efi_get_device_by_path - find device by EFI Device Path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)  * @node: EFI Device Path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)  * @len: maximum length of EFI Device Path in bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)  * Parse a series of EFI Device Path nodes at @node and find the corresponding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)  * device.  If the device was found, its reference count is incremented and a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)  * pointer to it is returned.  The caller needs to drop the reference with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)  * put_device() after use.  The @node pointer is updated to point to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)  * location immediately after the "End of Hardware Device Path" node.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)  * If another Device Path instance follows, @len is decremented by the number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)  * of bytes consumed.  Otherwise @len is set to %0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)  * If a Device Path node is malformed or its corresponding device is not found,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)  * @node is updated to point to this offending node and an ERR_PTR is returned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)  * If @len is initially %0, the function returns %NULL.  Thus, to iterate over
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  * all instances in a path, the following idiom may be used:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)  *	while (!IS_ERR_OR_NULL(dev = efi_get_device_by_path(&node, &len))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)  *		// do something with dev
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)  *		put_device(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)  *	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)  *	if (IS_ERR(dev))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)  *		// report error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)  * Devices can only be found if they're already instantiated. Most buses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)  * instantiate devices in the "subsys" initcall level, hence the earliest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)  * initcall level in which this function should be called is "fs".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)  * Returns the device on success or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)  *	%ERR_PTR(-ENODEV) if no device was found,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)  *	%ERR_PTR(-EINVAL) if a node is malformed or exceeds @len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)  *	%ERR_PTR(-ENOTSUPP) if support for a node type is not yet implemented.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) struct device * __init efi_get_device_by_path(const struct efi_dev_path **node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 					      size_t *len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	struct device *parent = NULL, *child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	long ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	if (!*len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	while (!ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		if (*len < 4 || *len < (*node)->header.length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 			ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		else if ((*node)->header.type		== EFI_DEV_ACPI &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 			 (*node)->header.sub_type	== EFI_DEV_BASIC_ACPI)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 			ret = parse_acpi_path(*node, parent, &child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		else if ((*node)->header.type		== EFI_DEV_HW &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 			 (*node)->header.sub_type	== EFI_DEV_PCI)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 			ret = parse_pci_path(*node, parent, &child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		else if (((*node)->header.type		== EFI_DEV_END_PATH ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 			  (*node)->header.type		== EFI_DEV_END_PATH2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 			ret = parse_end_path(*node, parent, &child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 			ret = -ENOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		put_device(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 			return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		parent = child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		*node  = (void *)*node + (*node)->header.length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		*len  -= (*node)->header.length;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	if (ret == EFI_DEV_END_ENTIRE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		*len = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	return child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }