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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IBM Real-Time Linux driver
4 *
5 * Copyright (C) IBM Corporation, 2010
6 *
7 * Author: Keith Mannthey <kmannth@us.ibm.com>
8 * Vernon Mauery <vernux@us.ibm.com>
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/kernel.h>
14#include <linux/delay.h>
15#include <linux/module.h>
16#include <linux/io.h>
17#include <linux/dmi.h>
18#include <linux/efi.h>
19#include <linux/mutex.h>
20#include <asm/bios_ebda.h>
21
22#include <linux/io-64-nonatomic-lo-hi.h>
23
24static bool force;
25module_param(force, bool, 0);
26MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
27
28static bool debug;
29module_param(debug, bool, 0644);
30MODULE_PARM_DESC(debug, "Show debug output");
31
32MODULE_DESCRIPTION("IBM Premium Real Time Mode (PRTM) driver");
33MODULE_LICENSE("GPL");
34MODULE_AUTHOR("Keith Mannthey <kmmanth@us.ibm.com>");
35MODULE_AUTHOR("Vernon Mauery <vernux@us.ibm.com>");
36
37#define RTL_ADDR_TYPE_IO 1
38#define RTL_ADDR_TYPE_MMIO 2
39
40#define RTL_CMD_ENTER_PRTM 1
41#define RTL_CMD_EXIT_PRTM 2
42
43/* The RTL table as presented by the EBDA: */
44struct ibm_rtl_table {
45 char signature[5]; /* signature should be "_RTL_" */
46 u8 version;
47 u8 rt_status;
48 u8 command;
49 u8 command_status;
50 u8 cmd_address_type;
51 u8 cmd_granularity;
52 u8 cmd_offset;
53 u16 reserve1;
54 u32 cmd_port_address; /* platform dependent address */
55 u32 cmd_port_value; /* platform dependent value */
56} __attribute__((packed));
57
58/* to locate "_RTL_" signature do a masked 5-byte integer compare */
59#define RTL_SIGNATURE 0x0000005f4c54525fULL
60#define RTL_MASK 0x000000ffffffffffULL
61
62#define RTL_DEBUG(fmt, ...) \
63do { \
64 if (debug) \
65 pr_info(fmt, ##__VA_ARGS__); \
66} while (0)
67
68static DEFINE_MUTEX(rtl_lock);
69static struct ibm_rtl_table __iomem *rtl_table;
70static void __iomem *ebda_map;
71static void __iomem *rtl_cmd_addr;
72static u8 rtl_cmd_type;
73static u8 rtl_cmd_width;
74
75static void __iomem *rtl_port_map(phys_addr_t addr, unsigned long len)
76{
77 if (rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
78 return ioremap(addr, len);
79 return ioport_map(addr, len);
80}
81
82static void rtl_port_unmap(void __iomem *addr)
83{
84 if (addr && rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
85 iounmap(addr);
86 else
87 ioport_unmap(addr);
88}
89
90static int ibm_rtl_write(u8 value)
91{
92 int ret = 0, count = 0;
93 u32 cmd_port_val;
94
95 RTL_DEBUG("%s(%d)\n", __func__, value);
96
97 value = value == 1 ? RTL_CMD_ENTER_PRTM : RTL_CMD_EXIT_PRTM;
98
99 mutex_lock(&rtl_lock);
100
101 if (ioread8(&rtl_table->rt_status) != value) {
102 iowrite8(value, &rtl_table->command);
103
104 switch (rtl_cmd_width) {
105 case 8:
106 cmd_port_val = ioread8(&rtl_table->cmd_port_value);
107 RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
108 iowrite8((u8)cmd_port_val, rtl_cmd_addr);
109 break;
110 case 16:
111 cmd_port_val = ioread16(&rtl_table->cmd_port_value);
112 RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
113 iowrite16((u16)cmd_port_val, rtl_cmd_addr);
114 break;
115 case 32:
116 cmd_port_val = ioread32(&rtl_table->cmd_port_value);
117 RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
118 iowrite32(cmd_port_val, rtl_cmd_addr);
119 break;
120 }
121
122 while (ioread8(&rtl_table->command)) {
123 msleep(10);
124 if (count++ > 500) {
125 pr_err("Hardware not responding to "
126 "mode switch request\n");
127 ret = -EIO;
128 break;
129 }
130
131 }
132
133 if (ioread8(&rtl_table->command_status)) {
134 RTL_DEBUG("command_status reports failed command\n");
135 ret = -EIO;
136 }
137 }
138
139 mutex_unlock(&rtl_lock);
140 return ret;
141}
142
143static ssize_t rtl_show_version(struct device *dev,
144 struct device_attribute *attr,
145 char *buf)
146{
147 return sprintf(buf, "%d\n", (int)ioread8(&rtl_table->version));
148}
149
150static ssize_t rtl_show_state(struct device *dev,
151 struct device_attribute *attr,
152 char *buf)
153{
154 return sprintf(buf, "%d\n", ioread8(&rtl_table->rt_status));
155}
156
157static ssize_t rtl_set_state(struct device *dev,
158 struct device_attribute *attr,
159 const char *buf,
160 size_t count)
161{
162 ssize_t ret;
163
164 if (count < 1 || count > 2)
165 return -EINVAL;
166
167 switch (buf[0]) {
168 case '0':
169 ret = ibm_rtl_write(0);
170 break;
171 case '1':
172 ret = ibm_rtl_write(1);
173 break;
174 default:
175 ret = -EINVAL;
176 }
177 if (ret >= 0)
178 ret = count;
179
180 return ret;
181}
182
183static const struct bus_type rtl_subsys = {
184 .name = "ibm_rtl",
185 .dev_name = "ibm_rtl",
186};
187
188static DEVICE_ATTR(version, S_IRUGO, rtl_show_version, NULL);
189static DEVICE_ATTR(state, 0600, rtl_show_state, rtl_set_state);
190
191static struct device_attribute *rtl_attributes[] = {
192 &dev_attr_version,
193 &dev_attr_state,
194 NULL
195};
196
197
198static int rtl_setup_sysfs(void) {
199 int ret, i;
200
201 ret = subsys_system_register(&rtl_subsys, NULL);
202 if (!ret) {
203 struct device *dev_root = bus_get_dev_root(&rtl_subsys);
204
205 if (dev_root) {
206 for (i = 0; rtl_attributes[i]; i ++)
207 device_create_file(dev_root, rtl_attributes[i]);
208 put_device(dev_root);
209 }
210 }
211 return ret;
212}
213
214static void rtl_teardown_sysfs(void) {
215 struct device *dev_root = bus_get_dev_root(&rtl_subsys);
216 int i;
217
218 if (dev_root) {
219 for (i = 0; rtl_attributes[i]; i ++)
220 device_remove_file(dev_root, rtl_attributes[i]);
221 put_device(dev_root);
222 }
223 bus_unregister(&rtl_subsys);
224}
225
226
227static const struct dmi_system_id ibm_rtl_dmi_table[] __initconst = {
228 { \
229 .matches = { \
230 DMI_MATCH(DMI_SYS_VENDOR, "IBM"), \
231 }, \
232 },
233 { }
234};
235
236static int __init ibm_rtl_init(void) {
237 unsigned long ebda_addr, ebda_size;
238 unsigned int ebda_kb;
239 int ret = -ENODEV, i;
240
241 if (force)
242 pr_warn("module loaded by force\n");
243 /* first ensure that we are running on IBM HW */
244 else if (efi_enabled(EFI_BOOT) || !dmi_check_system(ibm_rtl_dmi_table))
245 return -ENODEV;
246
247 /* Get the address for the Extended BIOS Data Area */
248 ebda_addr = get_bios_ebda();
249 if (!ebda_addr) {
250 RTL_DEBUG("no BIOS EBDA found\n");
251 return -ENODEV;
252 }
253
254 ebda_map = ioremap(ebda_addr, 4);
255 if (!ebda_map)
256 return -ENOMEM;
257
258 /* First word in the EDBA is the Size in KB */
259 ebda_kb = ioread16(ebda_map);
260 RTL_DEBUG("EBDA is %d kB\n", ebda_kb);
261
262 if (ebda_kb == 0)
263 goto out;
264
265 iounmap(ebda_map);
266 ebda_size = ebda_kb*1024;
267
268 /* Remap the whole table */
269 ebda_map = ioremap(ebda_addr, ebda_size);
270 if (!ebda_map)
271 return -ENOMEM;
272
273 /* search for the _RTL_ signature at the start of the table */
274 for (i = 0 ; i < ebda_size/sizeof(unsigned int); i++) {
275 struct ibm_rtl_table __iomem * tmp;
276 tmp = (struct ibm_rtl_table __iomem *) (ebda_map+i);
277 if ((readq(&tmp->signature) & RTL_MASK) == RTL_SIGNATURE) {
278 phys_addr_t addr;
279 unsigned int plen;
280 RTL_DEBUG("found RTL_SIGNATURE at %p\n", tmp);
281 rtl_table = tmp;
282 /* The address, value, width and offset are platform
283 * dependent and found in the ibm_rtl_table */
284 rtl_cmd_width = ioread8(&rtl_table->cmd_granularity);
285 rtl_cmd_type = ioread8(&rtl_table->cmd_address_type);
286 RTL_DEBUG("rtl_cmd_width = %u, rtl_cmd_type = %u\n",
287 rtl_cmd_width, rtl_cmd_type);
288 addr = ioread32(&rtl_table->cmd_port_address);
289 RTL_DEBUG("addr = %#llx\n", (unsigned long long)addr);
290 plen = rtl_cmd_width/sizeof(char);
291 rtl_cmd_addr = rtl_port_map(addr, plen);
292 RTL_DEBUG("rtl_cmd_addr = %p\n", rtl_cmd_addr);
293 if (!rtl_cmd_addr) {
294 ret = -ENOMEM;
295 break;
296 }
297 ret = rtl_setup_sysfs();
298 break;
299 }
300 }
301
302out:
303 if (ret) {
304 iounmap(ebda_map);
305 rtl_port_unmap(rtl_cmd_addr);
306 }
307
308 return ret;
309}
310
311static void __exit ibm_rtl_exit(void)
312{
313 if (rtl_table) {
314 RTL_DEBUG("cleaning up");
315 /* do not leave the machine in SMI-free mode */
316 ibm_rtl_write(0);
317 /* unmap, unlink and remove all traces */
318 rtl_teardown_sysfs();
319 iounmap(ebda_map);
320 rtl_port_unmap(rtl_cmd_addr);
321 }
322}
323
324module_init(ibm_rtl_init);
325module_exit(ibm_rtl_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IBM Real-Time Linux driver
4 *
5 * Copyright (C) IBM Corporation, 2010
6 *
7 * Author: Keith Mannthey <kmannth@us.ibm.com>
8 * Vernon Mauery <vernux@us.ibm.com>
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/kernel.h>
14#include <linux/delay.h>
15#include <linux/module.h>
16#include <linux/io.h>
17#include <linux/dmi.h>
18#include <linux/efi.h>
19#include <linux/mutex.h>
20#include <asm/bios_ebda.h>
21
22#include <linux/io-64-nonatomic-lo-hi.h>
23
24static bool force;
25module_param(force, bool, 0);
26MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
27
28static bool debug;
29module_param(debug, bool, 0644);
30MODULE_PARM_DESC(debug, "Show debug output");
31
32MODULE_LICENSE("GPL");
33MODULE_AUTHOR("Keith Mannthey <kmmanth@us.ibm.com>");
34MODULE_AUTHOR("Vernon Mauery <vernux@us.ibm.com>");
35
36#define RTL_ADDR_TYPE_IO 1
37#define RTL_ADDR_TYPE_MMIO 2
38
39#define RTL_CMD_ENTER_PRTM 1
40#define RTL_CMD_EXIT_PRTM 2
41
42/* The RTL table as presented by the EBDA: */
43struct ibm_rtl_table {
44 char signature[5]; /* signature should be "_RTL_" */
45 u8 version;
46 u8 rt_status;
47 u8 command;
48 u8 command_status;
49 u8 cmd_address_type;
50 u8 cmd_granularity;
51 u8 cmd_offset;
52 u16 reserve1;
53 u32 cmd_port_address; /* platform dependent address */
54 u32 cmd_port_value; /* platform dependent value */
55} __attribute__((packed));
56
57/* to locate "_RTL_" signature do a masked 5-byte integer compare */
58#define RTL_SIGNATURE 0x0000005f4c54525fULL
59#define RTL_MASK 0x000000ffffffffffULL
60
61#define RTL_DEBUG(fmt, ...) \
62do { \
63 if (debug) \
64 pr_info(fmt, ##__VA_ARGS__); \
65} while (0)
66
67static DEFINE_MUTEX(rtl_lock);
68static struct ibm_rtl_table __iomem *rtl_table;
69static void __iomem *ebda_map;
70static void __iomem *rtl_cmd_addr;
71static u8 rtl_cmd_type;
72static u8 rtl_cmd_width;
73
74static void __iomem *rtl_port_map(phys_addr_t addr, unsigned long len)
75{
76 if (rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
77 return ioremap(addr, len);
78 return ioport_map(addr, len);
79}
80
81static void rtl_port_unmap(void __iomem *addr)
82{
83 if (addr && rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
84 iounmap(addr);
85 else
86 ioport_unmap(addr);
87}
88
89static int ibm_rtl_write(u8 value)
90{
91 int ret = 0, count = 0;
92 u32 cmd_port_val;
93
94 RTL_DEBUG("%s(%d)\n", __func__, value);
95
96 value = value == 1 ? RTL_CMD_ENTER_PRTM : RTL_CMD_EXIT_PRTM;
97
98 mutex_lock(&rtl_lock);
99
100 if (ioread8(&rtl_table->rt_status) != value) {
101 iowrite8(value, &rtl_table->command);
102
103 switch (rtl_cmd_width) {
104 case 8:
105 cmd_port_val = ioread8(&rtl_table->cmd_port_value);
106 RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
107 iowrite8((u8)cmd_port_val, rtl_cmd_addr);
108 break;
109 case 16:
110 cmd_port_val = ioread16(&rtl_table->cmd_port_value);
111 RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
112 iowrite16((u16)cmd_port_val, rtl_cmd_addr);
113 break;
114 case 32:
115 cmd_port_val = ioread32(&rtl_table->cmd_port_value);
116 RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
117 iowrite32(cmd_port_val, rtl_cmd_addr);
118 break;
119 }
120
121 while (ioread8(&rtl_table->command)) {
122 msleep(10);
123 if (count++ > 500) {
124 pr_err("Hardware not responding to "
125 "mode switch request\n");
126 ret = -EIO;
127 break;
128 }
129
130 }
131
132 if (ioread8(&rtl_table->command_status)) {
133 RTL_DEBUG("command_status reports failed command\n");
134 ret = -EIO;
135 }
136 }
137
138 mutex_unlock(&rtl_lock);
139 return ret;
140}
141
142static ssize_t rtl_show_version(struct device *dev,
143 struct device_attribute *attr,
144 char *buf)
145{
146 return sprintf(buf, "%d\n", (int)ioread8(&rtl_table->version));
147}
148
149static ssize_t rtl_show_state(struct device *dev,
150 struct device_attribute *attr,
151 char *buf)
152{
153 return sprintf(buf, "%d\n", ioread8(&rtl_table->rt_status));
154}
155
156static ssize_t rtl_set_state(struct device *dev,
157 struct device_attribute *attr,
158 const char *buf,
159 size_t count)
160{
161 ssize_t ret;
162
163 if (count < 1 || count > 2)
164 return -EINVAL;
165
166 switch (buf[0]) {
167 case '0':
168 ret = ibm_rtl_write(0);
169 break;
170 case '1':
171 ret = ibm_rtl_write(1);
172 break;
173 default:
174 ret = -EINVAL;
175 }
176 if (ret >= 0)
177 ret = count;
178
179 return ret;
180}
181
182static const struct bus_type rtl_subsys = {
183 .name = "ibm_rtl",
184 .dev_name = "ibm_rtl",
185};
186
187static DEVICE_ATTR(version, S_IRUGO, rtl_show_version, NULL);
188static DEVICE_ATTR(state, 0600, rtl_show_state, rtl_set_state);
189
190static struct device_attribute *rtl_attributes[] = {
191 &dev_attr_version,
192 &dev_attr_state,
193 NULL
194};
195
196
197static int rtl_setup_sysfs(void) {
198 int ret, i;
199
200 ret = subsys_system_register(&rtl_subsys, NULL);
201 if (!ret) {
202 struct device *dev_root = bus_get_dev_root(&rtl_subsys);
203
204 if (dev_root) {
205 for (i = 0; rtl_attributes[i]; i ++)
206 device_create_file(dev_root, rtl_attributes[i]);
207 put_device(dev_root);
208 }
209 }
210 return ret;
211}
212
213static void rtl_teardown_sysfs(void) {
214 struct device *dev_root = bus_get_dev_root(&rtl_subsys);
215 int i;
216
217 if (dev_root) {
218 for (i = 0; rtl_attributes[i]; i ++)
219 device_remove_file(dev_root, rtl_attributes[i]);
220 put_device(dev_root);
221 }
222 bus_unregister(&rtl_subsys);
223}
224
225
226static const struct dmi_system_id ibm_rtl_dmi_table[] __initconst = {
227 { \
228 .matches = { \
229 DMI_MATCH(DMI_SYS_VENDOR, "IBM"), \
230 }, \
231 },
232 { }
233};
234
235static int __init ibm_rtl_init(void) {
236 unsigned long ebda_addr, ebda_size;
237 unsigned int ebda_kb;
238 int ret = -ENODEV, i;
239
240 if (force)
241 pr_warn("module loaded by force\n");
242 /* first ensure that we are running on IBM HW */
243 else if (efi_enabled(EFI_BOOT) || !dmi_check_system(ibm_rtl_dmi_table))
244 return -ENODEV;
245
246 /* Get the address for the Extended BIOS Data Area */
247 ebda_addr = get_bios_ebda();
248 if (!ebda_addr) {
249 RTL_DEBUG("no BIOS EBDA found\n");
250 return -ENODEV;
251 }
252
253 ebda_map = ioremap(ebda_addr, 4);
254 if (!ebda_map)
255 return -ENOMEM;
256
257 /* First word in the EDBA is the Size in KB */
258 ebda_kb = ioread16(ebda_map);
259 RTL_DEBUG("EBDA is %d kB\n", ebda_kb);
260
261 if (ebda_kb == 0)
262 goto out;
263
264 iounmap(ebda_map);
265 ebda_size = ebda_kb*1024;
266
267 /* Remap the whole table */
268 ebda_map = ioremap(ebda_addr, ebda_size);
269 if (!ebda_map)
270 return -ENOMEM;
271
272 /* search for the _RTL_ signature at the start of the table */
273 for (i = 0 ; i < ebda_size/sizeof(unsigned int); i++) {
274 struct ibm_rtl_table __iomem * tmp;
275 tmp = (struct ibm_rtl_table __iomem *) (ebda_map+i);
276 if ((readq(&tmp->signature) & RTL_MASK) == RTL_SIGNATURE) {
277 phys_addr_t addr;
278 unsigned int plen;
279 RTL_DEBUG("found RTL_SIGNATURE at %p\n", tmp);
280 rtl_table = tmp;
281 /* The address, value, width and offset are platform
282 * dependent and found in the ibm_rtl_table */
283 rtl_cmd_width = ioread8(&rtl_table->cmd_granularity);
284 rtl_cmd_type = ioread8(&rtl_table->cmd_address_type);
285 RTL_DEBUG("rtl_cmd_width = %u, rtl_cmd_type = %u\n",
286 rtl_cmd_width, rtl_cmd_type);
287 addr = ioread32(&rtl_table->cmd_port_address);
288 RTL_DEBUG("addr = %#llx\n", (unsigned long long)addr);
289 plen = rtl_cmd_width/sizeof(char);
290 rtl_cmd_addr = rtl_port_map(addr, plen);
291 RTL_DEBUG("rtl_cmd_addr = %p\n", rtl_cmd_addr);
292 if (!rtl_cmd_addr) {
293 ret = -ENOMEM;
294 break;
295 }
296 ret = rtl_setup_sysfs();
297 break;
298 }
299 }
300
301out:
302 if (ret) {
303 iounmap(ebda_map);
304 rtl_port_unmap(rtl_cmd_addr);
305 }
306
307 return ret;
308}
309
310static void __exit ibm_rtl_exit(void)
311{
312 if (rtl_table) {
313 RTL_DEBUG("cleaning up");
314 /* do not leave the machine in SMI-free mode */
315 ibm_rtl_write(0);
316 /* unmap, unlink and remove all traces */
317 rtl_teardown_sysfs();
318 iounmap(ebda_map);
319 rtl_port_unmap(rtl_cmd_addr);
320 }
321}
322
323module_init(ibm_rtl_init);
324module_exit(ibm_rtl_exit);