RISC-V: Fix a race condition during kernel stack overflow
[platform/kernel/linux-starfive.git] / drivers / eisa / eisa-bus.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * EISA bus support functions for sysfs.
4  *
5  * (C) 2002, 2003 Marc Zyngier <maz@wild-wind.fr.eu.org>
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/device.h>
10 #include <linux/eisa.h>
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/ioport.h>
16 #include <asm/io.h>
17
18 #define SLOT_ADDRESS(r,n) (r->bus_base_addr + (0x1000 * n))
19
20 #define EISA_DEVINFO(i,s) { .id = { .sig = i }, .name = s }
21
22 struct eisa_device_info {
23         struct eisa_device_id id;
24         char name[50];
25 };
26
27 #ifdef CONFIG_EISA_NAMES
28 static struct eisa_device_info __initdata eisa_table[] = {
29 #include "devlist.h"
30 };
31 #define EISA_INFOS (sizeof (eisa_table) / (sizeof (struct eisa_device_info)))
32 #endif
33
34 #define EISA_MAX_FORCED_DEV 16
35
36 static int enable_dev[EISA_MAX_FORCED_DEV];
37 static unsigned int enable_dev_count;
38 static int disable_dev[EISA_MAX_FORCED_DEV];
39 static unsigned int disable_dev_count;
40
41 static int is_forced_dev(int *forced_tab,
42                          int forced_count,
43                          struct eisa_root_device *root,
44                          struct eisa_device *edev)
45 {
46         int i, x;
47
48         for (i = 0; i < forced_count; i++) {
49                 x = (root->bus_nr << 8) | edev->slot;
50                 if (forced_tab[i] == x)
51                         return 1;
52         }
53
54         return 0;
55 }
56
57 static void __init eisa_name_device(struct eisa_device *edev)
58 {
59 #ifdef CONFIG_EISA_NAMES
60         int i;
61         for (i = 0; i < EISA_INFOS; i++) {
62                 if (!strcmp(edev->id.sig, eisa_table[i].id.sig)) {
63                         strlcpy(edev->pretty_name,
64                                 eisa_table[i].name,
65                                 sizeof(edev->pretty_name));
66                         return;
67                 }
68         }
69
70         /* No name was found */
71         sprintf(edev->pretty_name, "EISA device %.7s", edev->id.sig);
72 #endif
73 }
74
75 static char __init *decode_eisa_sig(unsigned long addr)
76 {
77         static char sig_str[EISA_SIG_LEN];
78         u8 sig[4];
79         u16 rev;
80         int i;
81
82         for (i = 0; i < 4; i++) {
83 #ifdef CONFIG_EISA_VLB_PRIMING
84                 /*
85                  * This ugly stuff is used to wake up VL-bus cards
86                  * (AHA-284x is the only known example), so we can
87                  * read the EISA id.
88                  *
89                  * Thankfully, this only exists on x86...
90                  */
91                 outb(0x80 + i, addr);
92 #endif
93                 sig[i] = inb(addr + i);
94
95                 if (!i && (sig[0] & 0x80))
96                         return NULL;
97         }
98
99         sig_str[0] = ((sig[0] >> 2) & 0x1f) + ('A' - 1);
100         sig_str[1] = (((sig[0] & 3) << 3) | (sig[1] >> 5)) + ('A' - 1);
101         sig_str[2] = (sig[1] & 0x1f) + ('A' - 1);
102         rev = (sig[2] << 8) | sig[3];
103         sprintf(sig_str + 3, "%04X", rev);
104
105         return sig_str;
106 }
107
108 static int eisa_bus_match(struct device *dev, struct device_driver *drv)
109 {
110         struct eisa_device *edev = to_eisa_device(dev);
111         struct eisa_driver *edrv = to_eisa_driver(drv);
112         const struct eisa_device_id *eids = edrv->id_table;
113
114         if (!eids)
115                 return 0;
116
117         while (strlen(eids->sig)) {
118                 if (!strcmp(eids->sig, edev->id.sig) &&
119                     edev->state & EISA_CONFIG_ENABLED) {
120                         edev->id.driver_data = eids->driver_data;
121                         return 1;
122                 }
123
124                 eids++;
125         }
126
127         return 0;
128 }
129
130 static int eisa_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
131 {
132         struct eisa_device *edev = to_eisa_device(dev);
133
134         add_uevent_var(env, "MODALIAS=" EISA_DEVICE_MODALIAS_FMT, edev->id.sig);
135         return 0;
136 }
137
138 struct bus_type eisa_bus_type = {
139         .name  = "eisa",
140         .match = eisa_bus_match,
141         .uevent = eisa_bus_uevent,
142 };
143 EXPORT_SYMBOL(eisa_bus_type);
144
145 int eisa_driver_register(struct eisa_driver *edrv)
146 {
147         edrv->driver.bus = &eisa_bus_type;
148         return driver_register(&edrv->driver);
149 }
150 EXPORT_SYMBOL(eisa_driver_register);
151
152 void eisa_driver_unregister(struct eisa_driver *edrv)
153 {
154         driver_unregister(&edrv->driver);
155 }
156 EXPORT_SYMBOL(eisa_driver_unregister);
157
158 static ssize_t signature_show(struct device *dev,
159                               struct device_attribute *attr, char *buf)
160 {
161         struct eisa_device *edev = to_eisa_device(dev);
162         return sprintf(buf, "%s\n", edev->id.sig);
163 }
164 static DEVICE_ATTR_RO(signature);
165
166 static ssize_t enabled_show(struct device *dev,
167                             struct device_attribute *attr, char *buf)
168 {
169         struct eisa_device *edev = to_eisa_device(dev);
170         return sprintf(buf, "%d\n", edev->state & EISA_CONFIG_ENABLED);
171 }
172 static DEVICE_ATTR_RO(enabled);
173
174 static ssize_t modalias_show(struct device *dev,
175                              struct device_attribute *attr, char *buf)
176 {
177         struct eisa_device *edev = to_eisa_device(dev);
178         return sprintf(buf, EISA_DEVICE_MODALIAS_FMT "\n", edev->id.sig);
179 }
180 static DEVICE_ATTR_RO(modalias);
181
182 static int __init eisa_init_device(struct eisa_root_device *root,
183                                    struct eisa_device *edev,
184                                    int slot)
185 {
186         char *sig;
187         unsigned long sig_addr;
188         int i;
189
190         sig_addr = SLOT_ADDRESS(root, slot) + EISA_VENDOR_ID_OFFSET;
191
192         sig = decode_eisa_sig(sig_addr);
193         if (!sig)
194                 return -1;      /* No EISA device here */
195
196         memcpy(edev->id.sig, sig, EISA_SIG_LEN);
197         edev->slot = slot;
198         edev->state = inb(SLOT_ADDRESS(root, slot) + EISA_CONFIG_OFFSET)
199                       & EISA_CONFIG_ENABLED;
200         edev->base_addr = SLOT_ADDRESS(root, slot);
201         edev->dma_mask = root->dma_mask; /* Default DMA mask */
202         eisa_name_device(edev);
203         edev->dev.parent = root->dev;
204         edev->dev.bus = &eisa_bus_type;
205         edev->dev.dma_mask = &edev->dma_mask;
206         edev->dev.coherent_dma_mask = edev->dma_mask;
207         dev_set_name(&edev->dev, "%02X:%02X", root->bus_nr, slot);
208
209         for (i = 0; i < EISA_MAX_RESOURCES; i++) {
210 #ifdef CONFIG_EISA_NAMES
211                 edev->res[i].name = edev->pretty_name;
212 #else
213                 edev->res[i].name = edev->id.sig;
214 #endif
215         }
216
217         if (is_forced_dev(enable_dev, enable_dev_count, root, edev))
218                 edev->state = EISA_CONFIG_ENABLED | EISA_CONFIG_FORCED;
219
220         if (is_forced_dev(disable_dev, disable_dev_count, root, edev))
221                 edev->state = EISA_CONFIG_FORCED;
222
223         return 0;
224 }
225
226 static int __init eisa_register_device(struct eisa_device *edev)
227 {
228         int rc = device_register(&edev->dev);
229         if (rc) {
230                 put_device(&edev->dev);
231                 return rc;
232         }
233
234         rc = device_create_file(&edev->dev, &dev_attr_signature);
235         if (rc)
236                 goto err_devreg;
237         rc = device_create_file(&edev->dev, &dev_attr_enabled);
238         if (rc)
239                 goto err_sig;
240         rc = device_create_file(&edev->dev, &dev_attr_modalias);
241         if (rc)
242                 goto err_enab;
243
244         return 0;
245
246 err_enab:
247         device_remove_file(&edev->dev, &dev_attr_enabled);
248 err_sig:
249         device_remove_file(&edev->dev, &dev_attr_signature);
250 err_devreg:
251         device_unregister(&edev->dev);
252         return rc;
253 }
254
255 static int __init eisa_request_resources(struct eisa_root_device *root,
256                                          struct eisa_device *edev,
257                                          int slot)
258 {
259         int i;
260
261         for (i = 0; i < EISA_MAX_RESOURCES; i++) {
262                 /* Don't register resource for slot 0, since this is
263                  * very likely to fail... :-( Instead, grab the EISA
264                  * id, now we can display something in /proc/ioports.
265                  */
266
267                 /* Only one region for mainboard */
268                 if (!slot && i > 0) {
269                         edev->res[i].start = edev->res[i].end = 0;
270                         continue;
271                 }
272
273                 if (slot) {
274                         edev->res[i].name  = NULL;
275                         edev->res[i].start = SLOT_ADDRESS(root, slot)
276                                              + (i * 0x400);
277                         edev->res[i].end   = edev->res[i].start + 0xff;
278                         edev->res[i].flags = IORESOURCE_IO;
279                 } else {
280                         edev->res[i].name  = NULL;
281                         edev->res[i].start = SLOT_ADDRESS(root, slot)
282                                              + EISA_VENDOR_ID_OFFSET;
283                         edev->res[i].end   = edev->res[i].start + 3;
284                         edev->res[i].flags = IORESOURCE_IO | IORESOURCE_BUSY;
285                 }
286
287                 if (request_resource(root->res, &edev->res[i]))
288                         goto failed;
289         }
290
291         return 0;
292
293  failed:
294         while (--i >= 0)
295                 release_resource(&edev->res[i]);
296
297         return -1;
298 }
299
300 static void __init eisa_release_resources(struct eisa_device *edev)
301 {
302         int i;
303
304         for (i = 0; i < EISA_MAX_RESOURCES; i++)
305                 if (edev->res[i].start || edev->res[i].end)
306                         release_resource(&edev->res[i]);
307 }
308
309 static int __init eisa_probe(struct eisa_root_device *root)
310 {
311         int i, c;
312         struct eisa_device *edev;
313         char *enabled_str;
314
315         dev_info(root->dev, "Probing EISA bus %d\n", root->bus_nr);
316
317         /* First try to get hold of slot 0. If there is no device
318          * here, simply fail, unless root->force_probe is set. */
319
320         edev = kzalloc(sizeof(*edev), GFP_KERNEL);
321         if (!edev)
322                 return -ENOMEM;
323
324         if (eisa_request_resources(root, edev, 0)) {
325                 dev_warn(root->dev,
326                          "EISA: Cannot allocate resource for mainboard\n");
327                 kfree(edev);
328                 if (!root->force_probe)
329                         return -EBUSY;
330                 goto force_probe;
331         }
332
333         if (eisa_init_device(root, edev, 0)) {
334                 eisa_release_resources(edev);
335                 kfree(edev);
336                 if (!root->force_probe)
337                         return -ENODEV;
338                 goto force_probe;
339         }
340
341         dev_info(&edev->dev, "EISA: Mainboard %s detected\n", edev->id.sig);
342
343         if (eisa_register_device(edev)) {
344                 dev_err(&edev->dev, "EISA: Failed to register %s\n",
345                         edev->id.sig);
346                 eisa_release_resources(edev);
347                 kfree(edev);
348         }
349
350  force_probe:
351
352         for (c = 0, i = 1; i <= root->slots; i++) {
353                 edev = kzalloc(sizeof(*edev), GFP_KERNEL);
354                 if (!edev) {
355                         dev_err(root->dev, "EISA: Out of memory for slot %d\n",
356                                 i);
357                         continue;
358                 }
359
360                 if (eisa_request_resources(root, edev, i)) {
361                         dev_warn(root->dev,
362                                  "Cannot allocate resource for EISA slot %d\n",
363                                  i);
364                         kfree(edev);
365                         continue;
366                 }
367
368                 if (eisa_init_device(root, edev, i)) {
369                         eisa_release_resources(edev);
370                         kfree(edev);
371                         continue;
372                 }
373
374                 if (edev->state == (EISA_CONFIG_ENABLED | EISA_CONFIG_FORCED))
375                         enabled_str = " (forced enabled)";
376                 else if (edev->state == EISA_CONFIG_FORCED)
377                         enabled_str = " (forced disabled)";
378                 else if (edev->state == 0)
379                         enabled_str = " (disabled)";
380                 else
381                         enabled_str = "";
382
383                 dev_info(&edev->dev, "EISA: slot %d: %s detected%s\n", i,
384                          edev->id.sig, enabled_str);
385
386                 c++;
387
388                 if (eisa_register_device(edev)) {
389                         dev_err(&edev->dev, "EISA: Failed to register %s\n",
390                                 edev->id.sig);
391                         eisa_release_resources(edev);
392                         kfree(edev);
393                 }
394         }
395
396         dev_info(root->dev, "EISA: Detected %d card%s\n", c, c == 1 ? "" : "s");
397         return 0;
398 }
399
400 static struct resource eisa_root_res = {
401         .name  = "EISA root resource",
402         .start = 0,
403         .end   = 0xffffffff,
404         .flags = IORESOURCE_IO,
405 };
406
407 static int eisa_bus_count;
408
409 int __init eisa_root_register(struct eisa_root_device *root)
410 {
411         int err;
412
413         /* Use our own resources to check if this bus base address has
414          * been already registered. This prevents the virtual root
415          * device from registering after the real one has, for
416          * example... */
417
418         root->eisa_root_res.name  = eisa_root_res.name;
419         root->eisa_root_res.start = root->res->start;
420         root->eisa_root_res.end   = root->res->end;
421         root->eisa_root_res.flags = IORESOURCE_BUSY;
422
423         err = request_resource(&eisa_root_res, &root->eisa_root_res);
424         if (err)
425                 return err;
426
427         root->bus_nr = eisa_bus_count++;
428
429         err = eisa_probe(root);
430         if (err)
431                 release_resource(&root->eisa_root_res);
432
433         return err;
434 }
435
436 static int __init eisa_init(void)
437 {
438         int r;
439
440         r = bus_register(&eisa_bus_type);
441         if (r)
442                 return r;
443
444         printk(KERN_INFO "EISA bus registered\n");
445         return 0;
446 }
447
448 module_param_array(enable_dev, int, &enable_dev_count, 0444);
449 module_param_array(disable_dev, int, &disable_dev_count, 0444);
450
451 postcore_initcall(eisa_init);
452
453 int EISA_bus;           /* for legacy drivers */
454 EXPORT_SYMBOL(EISA_bus);