2 * Common functions for kernel modules using Dell SMBIOS
4 * Copyright (c) Red Hat <mjg@redhat.com>
5 * Copyright (c) 2014 Gabriele Mazzotta <gabriele.mzt@gmail.com>
6 * Copyright (c) 2014 Pali Rohár <pali.rohar@gmail.com>
8 * Based on documentation in the libsmbios package:
9 * Copyright (C) 2005-2014 Dell Inc.
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/dmi.h>
19 #include <linux/gfp.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
23 #include "../../firmware/dcdbas.h"
24 #include "dell-smbios.h"
26 struct calling_interface_structure {
27 struct dmi_header header;
31 struct calling_interface_token tokens[];
34 struct calling_interface_buffer *buffer;
35 EXPORT_SYMBOL_GPL(buffer);
36 static DEFINE_MUTEX(buffer_mutex);
38 static int da_command_address;
39 static int da_command_code;
40 static int da_num_tokens;
41 struct calling_interface_token *da_tokens;
42 EXPORT_SYMBOL_GPL(da_tokens);
44 void dell_smbios_get_buffer(void)
46 mutex_lock(&buffer_mutex);
47 dell_smbios_clear_buffer();
49 EXPORT_SYMBOL_GPL(dell_smbios_get_buffer);
51 void dell_smbios_clear_buffer(void)
53 memset(buffer, 0, sizeof(struct calling_interface_buffer));
55 EXPORT_SYMBOL_GPL(dell_smbios_clear_buffer);
57 void dell_smbios_release_buffer(void)
59 mutex_unlock(&buffer_mutex);
61 EXPORT_SYMBOL_GPL(dell_smbios_release_buffer);
63 void dell_smbios_send_request(int class, int select)
65 struct smi_cmd command;
67 command.magic = SMI_CMD_MAGIC;
68 command.command_address = da_command_address;
69 command.command_code = da_command_code;
70 command.ebx = virt_to_phys(buffer);
71 command.ecx = 0x42534931;
73 buffer->class = class;
74 buffer->select = select;
76 dcdbas_smi_request(&command);
78 EXPORT_SYMBOL_GPL(dell_smbios_send_request);
80 int find_token_id(int tokenid)
84 for (i = 0; i < da_num_tokens; i++) {
85 if (da_tokens[i].tokenID == tokenid)
91 EXPORT_SYMBOL_GPL(find_token_id);
93 int find_token_location(int tokenid)
97 id = find_token_id(tokenid);
101 return da_tokens[id].location;
103 EXPORT_SYMBOL_GPL(find_token_location);
105 static void __init parse_da_table(const struct dmi_header *dm)
107 /* Final token is a terminator, so we don't want to copy it */
108 int tokens = (dm->length-11)/sizeof(struct calling_interface_token)-1;
109 struct calling_interface_token *new_da_tokens;
110 struct calling_interface_structure *table =
111 container_of(dm, struct calling_interface_structure, header);
113 /* 4 bytes of table header, plus 7 bytes of Dell header, plus at least
119 da_command_address = table->cmdIOAddress;
120 da_command_code = table->cmdIOCode;
122 new_da_tokens = krealloc(da_tokens, (da_num_tokens + tokens) *
123 sizeof(struct calling_interface_token),
128 da_tokens = new_da_tokens;
130 memcpy(da_tokens+da_num_tokens, table->tokens,
131 sizeof(struct calling_interface_token) * tokens);
133 da_num_tokens += tokens;
136 static void __init find_tokens(const struct dmi_header *dm, void *dummy)
139 case 0xd4: /* Indexed IO */
140 case 0xd5: /* Protected Area Type 1 */
141 case 0xd6: /* Protected Area Type 2 */
143 case 0xda: /* Calling interface */
149 static int __init dell_smbios_init(void)
153 dmi_walk(find_tokens, NULL);
156 pr_info("Unable to find dmi tokens\n");
161 * Allocate buffer below 4GB for SMI data--only 32-bit physical addr
162 * is passed to SMI handler.
164 buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32);
177 static void __exit dell_smbios_exit(void)
180 free_page((unsigned long)buffer);
183 subsys_initcall(dell_smbios_init);
184 module_exit(dell_smbios_exit);
186 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
187 MODULE_AUTHOR("Gabriele Mazzotta <gabriele.mzt@gmail.com>");
188 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
189 MODULE_DESCRIPTION("Common functions for kernel modules using Dell SMBIOS");
190 MODULE_LICENSE("GPL");