1 /*
2 * drivers/sbus/char/jsflash.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds (drivers/char/mem.c)
5 * Copyright (C) 1997 Eddie C. Dost (drivers/sbus/char/flash.c)
6 * Copyright (C) 1997-2000 Pavel Machek <pavel@ucw.cz> (drivers/block/nbd.c)
7 * Copyright (C) 1999-2000 Pete Zaitcev
8 *
9 * This driver is used to program OS into a Flash SIMM on
10 * Krups and Espresso platforms.
11 *
12 * TODO: do not allow erase/programming if file systems are mounted.
13 * TODO: Erase/program both banks of a 8MB SIMM.
14 *
15 * It is anticipated that programming an OS Flash will be a routine
16 * procedure. In the same time it is exceedingly dangerous because
17 * a user can program its OBP flash with OS image and effectively
18 * kill the machine.
19 *
20 * This driver uses an interface different from Eddie's flash.c
21 * as a silly safeguard.
22 *
23 * XXX The flash.c manipulates page caching characteristics in a certain
24 * dubious way; also it assumes that remap_pfn_range() can remap
25 * PCI bus locations, which may be false. ioremap() must be used
26 * instead. We should discuss this.
27 */
28
29 #include <linux/module.h>
30 #include <linux/mutex.h>
31 #include <linux/types.h>
32 #include <linux/errno.h>
33 #include <linux/miscdevice.h>
34 #include <linux/fcntl.h>
35 #include <linux/poll.h>
36 #include <linux/init.h>
37 #include <linux/string.h>
38 #include <linux/genhd.h>
39 #include <linux/blkdev.h>
40 #include <asm/uaccess.h>
41 #include <asm/pgtable.h>
42 #include <asm/io.h>
43 #include <asm/pcic.h>
44 #include <asm/oplib.h>
45
46 #include <asm/jsflash.h> /* ioctl arguments. <linux/> ?? */
47 #define JSFIDSZ (sizeof(struct jsflash_ident_arg))
48 #define JSFPRGSZ (sizeof(struct jsflash_program_arg))
49
50 /*
51 * Our device numbers have no business in system headers.
52 * The only thing a user knows is the device name /dev/jsflash.
53 *
54 * Block devices are laid out like this:
55 * minor+0 - Bootstrap, for 8MB SIMM 0x20400000[0x800000]
56 * minor+1 - Filesystem to mount, normally 0x20400400[0x7ffc00]
57 * minor+2 - Whole flash area for any case... 0x20000000[0x01000000]
58 * Total 3 minors per flash device.
59 *
60 * It is easier to have static size vectors, so we define
61 * a total minor range JSF_MAX, which must cover all minors.
62 */
63 /* character device */
64 #define JSF_MINOR 178 /* 178 is registered with hpa */
65 /* block device */
66 #define JSF_MAX 3 /* 3 minors wasted total so far. */
67 #define JSF_NPART 3 /* 3 minors per flash device */
68 #define JSF_PART_BITS 2 /* 2 bits of minors to cover JSF_NPART */
69 #define JSF_PART_MASK 0x3 /* 2 bits mask */
70
71 static DEFINE_MUTEX(jsf_mutex);
72
73 /*
74 * Access functions.
75 * We could ioremap(), but it's easier this way.
76 */
jsf_inl(unsigned long addr)77 static unsigned int jsf_inl(unsigned long addr)
78 {
79 unsigned long retval;
80
81 __asm__ __volatile__("lda [%1] %2, %0\n\t" :
82 "=r" (retval) :
83 "r" (addr), "i" (ASI_M_BYPASS));
84 return retval;
85 }
86
jsf_outl(unsigned long addr,__u32 data)87 static void jsf_outl(unsigned long addr, __u32 data)
88 {
89
90 __asm__ __volatile__("sta %0, [%1] %2\n\t" : :
91 "r" (data), "r" (addr), "i" (ASI_M_BYPASS) :
92 "memory");
93 }
94
95 /*
96 * soft carrier
97 */
98
99 struct jsfd_part {
100 unsigned long dbase;
101 unsigned long dsize;
102 };
103
104 struct jsflash {
105 unsigned long base;
106 unsigned long size;
107 unsigned long busy; /* In use? */
108 struct jsflash_ident_arg id;
109 /* int mbase; */ /* Minor base, typically zero */
110 struct jsfd_part dv[JSF_NPART];
111 };
112
113 /*
114 * We do not map normal memory or obio as a safety precaution.
115 * But offsets are real, for ease of userland programming.
116 */
117 #define JSF_BASE_TOP 0x30000000
118 #define JSF_BASE_ALL 0x20000000
119
120 #define JSF_BASE_JK 0x20400000
121
122 /*
123 */
124 static struct gendisk *jsfd_disk[JSF_MAX];
125
126 /*
127 * Let's pretend we may have several of these...
128 */
129 static struct jsflash jsf0;
130
131 /*
132 * Wait for AMD to finish its embedded algorithm.
133 * We use the Toggle bit DQ6 (0x40) because it does not
134 * depend on the data value as /DATA bit DQ7 does.
135 *
136 * XXX Do we need any timeout here? So far it never hanged, beware broken hw.
137 */
jsf_wait(unsigned long p)138 static void jsf_wait(unsigned long p) {
139 unsigned int x1, x2;
140
141 for (;;) {
142 x1 = jsf_inl(p);
143 x2 = jsf_inl(p);
144 if ((x1 & 0x40404040) == (x2 & 0x40404040)) return;
145 }
146 }
147
148 /*
149 * Programming will only work if Flash is clean,
150 * we leave it to the programmer application.
151 *
152 * AMD must be programmed one byte at a time;
153 * thus, Simple Tech SIMM must be written 4 bytes at a time.
154 *
155 * Write waits for the chip to become ready after the write
156 * was finished. This is done so that application would read
157 * consistent data after the write is done.
158 */
jsf_write4(unsigned long fa,u32 data)159 static void jsf_write4(unsigned long fa, u32 data) {
160
161 jsf_outl(fa, 0xAAAAAAAA); /* Unlock 1 Write 1 */
162 jsf_outl(fa, 0x55555555); /* Unlock 1 Write 2 */
163 jsf_outl(fa, 0xA0A0A0A0); /* Byte Program */
164 jsf_outl(fa, data);
165
166 jsf_wait(fa);
167 }
168
169 /*
170 */
jsfd_read(char * buf,unsigned long p,size_t togo)171 static void jsfd_read(char *buf, unsigned long p, size_t togo) {
172 union byte4 {
173 char s[4];
174 unsigned int n;
175 } b;
176
177 while (togo >= 4) {
178 togo -= 4;
179 b.n = jsf_inl(p);
180 memcpy(buf, b.s, 4);
181 p += 4;
182 buf += 4;
183 }
184 }
185
jsfd_do_request(struct request_queue * q)186 static void jsfd_do_request(struct request_queue *q)
187 {
188 struct request *req;
189
190 req = blk_fetch_request(q);
191 while (req) {
192 struct jsfd_part *jdp = req->rq_disk->private_data;
193 unsigned long offset = blk_rq_pos(req) << 9;
194 size_t len = blk_rq_cur_bytes(req);
195 int err = -EIO;
196
197 if ((offset + len) > jdp->dsize)
198 goto end;
199
200 if (rq_data_dir(req) != READ) {
201 printk(KERN_ERR "jsfd: write\n");
202 goto end;
203 }
204
205 if ((jdp->dbase & 0xff000000) != 0x20000000) {
206 printk(KERN_ERR "jsfd: bad base %x\n", (int)jdp->dbase);
207 goto end;
208 }
209
210 jsfd_read(req->buffer, jdp->dbase + offset, len);
211 err = 0;
212 end:
213 if (!__blk_end_request_cur(req, err))
214 req = blk_fetch_request(q);
215 }
216 }
217
218 /*
219 * The memory devices use the full 32/64 bits of the offset, and so we cannot
220 * check against negative addresses: they are ok. The return value is weird,
221 * though, in that case (0).
222 *
223 * also note that seeking relative to the "end of file" isn't supported:
224 * it has no meaning, so it returns -EINVAL.
225 */
jsf_lseek(struct file * file,loff_t offset,int orig)226 static loff_t jsf_lseek(struct file * file, loff_t offset, int orig)
227 {
228 loff_t ret;
229
230 mutex_lock(&jsf_mutex);
231 switch (orig) {
232 case 0:
233 file->f_pos = offset;
234 ret = file->f_pos;
235 break;
236 case 1:
237 file->f_pos += offset;
238 ret = file->f_pos;
239 break;
240 default:
241 ret = -EINVAL;
242 }
243 mutex_unlock(&jsf_mutex);
244 return ret;
245 }
246
247 /*
248 * OS SIMM Cannot be read in other size but a 32bits word.
249 */
jsf_read(struct file * file,char __user * buf,size_t togo,loff_t * ppos)250 static ssize_t jsf_read(struct file * file, char __user * buf,
251 size_t togo, loff_t *ppos)
252 {
253 unsigned long p = *ppos;
254 char __user *tmp = buf;
255
256 union byte4 {
257 char s[4];
258 unsigned int n;
259 } b;
260
261 if (p < JSF_BASE_ALL || p >= JSF_BASE_TOP) {
262 return 0;
263 }
264
265 if ((p + togo) < p /* wrap */
266 || (p + togo) >= JSF_BASE_TOP) {
267 togo = JSF_BASE_TOP - p;
268 }
269
270 if (p < JSF_BASE_ALL && togo != 0) {
271 #if 0 /* __bzero XXX */
272 size_t x = JSF_BASE_ALL - p;
273 if (x > togo) x = togo;
274 clear_user(tmp, x);
275 tmp += x;
276 p += x;
277 togo -= x;
278 #else
279 /*
280 * Implementation of clear_user() calls __bzero
281 * without regard to modversions,
282 * so we cannot build a module.
283 */
284 return 0;
285 #endif
286 }
287
288 while (togo >= 4) {
289 togo -= 4;
290 b.n = jsf_inl(p);
291 if (copy_to_user(tmp, b.s, 4))
292 return -EFAULT;
293 tmp += 4;
294 p += 4;
295 }
296
297 /*
298 * XXX Small togo may remain if 1 byte is ordered.
299 * It would be nice if we did a word size read and unpacked it.
300 */
301
302 *ppos = p;
303 return tmp-buf;
304 }
305
jsf_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)306 static ssize_t jsf_write(struct file * file, const char __user * buf,
307 size_t count, loff_t *ppos)
308 {
309 return -ENOSPC;
310 }
311
312 /*
313 */
jsf_ioctl_erase(unsigned long arg)314 static int jsf_ioctl_erase(unsigned long arg)
315 {
316 unsigned long p;
317
318 /* p = jsf0.base; hits wrong bank */
319 p = 0x20400000;
320
321 jsf_outl(p, 0xAAAAAAAA); /* Unlock 1 Write 1 */
322 jsf_outl(p, 0x55555555); /* Unlock 1 Write 2 */
323 jsf_outl(p, 0x80808080); /* Erase setup */
324 jsf_outl(p, 0xAAAAAAAA); /* Unlock 2 Write 1 */
325 jsf_outl(p, 0x55555555); /* Unlock 2 Write 2 */
326 jsf_outl(p, 0x10101010); /* Chip erase */
327
328 #if 0
329 /*
330 * This code is ok, except that counter based timeout
331 * has no place in this world. Let's just drop timeouts...
332 */
333 {
334 int i;
335 __u32 x;
336 for (i = 0; i < 1000000; i++) {
337 x = jsf_inl(p);
338 if ((x & 0x80808080) == 0x80808080) break;
339 }
340 if ((x & 0x80808080) != 0x80808080) {
341 printk("jsf0: erase timeout with 0x%08x\n", x);
342 } else {
343 printk("jsf0: erase done with 0x%08x\n", x);
344 }
345 }
346 #else
347 jsf_wait(p);
348 #endif
349
350 return 0;
351 }
352
353 /*
354 * Program a block of flash.
355 * Very simple because we can do it byte by byte anyway.
356 */
jsf_ioctl_program(void __user * arg)357 static int jsf_ioctl_program(void __user *arg)
358 {
359 struct jsflash_program_arg abuf;
360 char __user *uptr;
361 unsigned long p;
362 unsigned int togo;
363 union {
364 unsigned int n;
365 char s[4];
366 } b;
367
368 if (copy_from_user(&abuf, arg, JSFPRGSZ))
369 return -EFAULT;
370 p = abuf.off;
371 togo = abuf.size;
372 if ((togo & 3) || (p & 3)) return -EINVAL;
373
374 uptr = (char __user *) (unsigned long) abuf.data;
375 while (togo != 0) {
376 togo -= 4;
377 if (copy_from_user(&b.s[0], uptr, 4))
378 return -EFAULT;
379 jsf_write4(p, b.n);
380 p += 4;
381 uptr += 4;
382 }
383
384 return 0;
385 }
386
jsf_ioctl(struct file * f,unsigned int cmd,unsigned long arg)387 static long jsf_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
388 {
389 mutex_lock(&jsf_mutex);
390 int error = -ENOTTY;
391 void __user *argp = (void __user *)arg;
392
393 if (!capable(CAP_SYS_ADMIN)) {
394 mutex_unlock(&jsf_mutex);
395 return -EPERM;
396 }
397 switch (cmd) {
398 case JSFLASH_IDENT:
399 if (copy_to_user(argp, &jsf0.id, JSFIDSZ)) {
400 mutex_unlock(&jsf_mutex);
401 return -EFAULT;
402 }
403 break;
404 case JSFLASH_ERASE:
405 error = jsf_ioctl_erase(arg);
406 break;
407 case JSFLASH_PROGRAM:
408 error = jsf_ioctl_program(argp);
409 break;
410 }
411
412 mutex_unlock(&jsf_mutex);
413 return error;
414 }
415
jsf_mmap(struct file * file,struct vm_area_struct * vma)416 static int jsf_mmap(struct file * file, struct vm_area_struct * vma)
417 {
418 return -ENXIO;
419 }
420
jsf_open(struct inode * inode,struct file * filp)421 static int jsf_open(struct inode * inode, struct file * filp)
422 {
423 mutex_lock(&jsf_mutex);
424 if (jsf0.base == 0) {
425 mutex_unlock(&jsf_mutex);
426 return -ENXIO;
427 }
428 if (test_and_set_bit(0, (void *)&jsf0.busy) != 0) {
429 mutex_unlock(&jsf_mutex);
430 return -EBUSY;
431 }
432
433 mutex_unlock(&jsf_mutex);
434 return 0; /* XXX What security? */
435 }
436
jsf_release(struct inode * inode,struct file * file)437 static int jsf_release(struct inode *inode, struct file *file)
438 {
439 jsf0.busy = 0;
440 return 0;
441 }
442
443 static const struct file_operations jsf_fops = {
444 .owner = THIS_MODULE,
445 .llseek = jsf_lseek,
446 .read = jsf_read,
447 .write = jsf_write,
448 .unlocked_ioctl = jsf_ioctl,
449 .mmap = jsf_mmap,
450 .open = jsf_open,
451 .release = jsf_release,
452 };
453
454 static struct miscdevice jsf_dev = { JSF_MINOR, "jsflash", &jsf_fops };
455
456 static const struct block_device_operations jsfd_fops = {
457 .owner = THIS_MODULE,
458 };
459
jsflash_init(void)460 static int jsflash_init(void)
461 {
462 int rc;
463 struct jsflash *jsf;
464 phandle node;
465 char banner[128];
466 struct linux_prom_registers reg0;
467
468 node = prom_getchild(prom_root_node);
469 node = prom_searchsiblings(node, "flash-memory");
470 if (node != 0 && (s32)node != -1) {
471 if (prom_getproperty(node, "reg",
472 (char *)®0, sizeof(reg0)) == -1) {
473 printk("jsflash: no \"reg\" property\n");
474 return -ENXIO;
475 }
476 if (reg0.which_io != 0) {
477 printk("jsflash: bus number nonzero: 0x%x:%x\n",
478 reg0.which_io, reg0.phys_addr);
479 return -ENXIO;
480 }
481 /*
482 * Flash may be somewhere else, for instance on Ebus.
483 * So, don't do the following check for IIep flash space.
484 */
485 #if 0
486 if ((reg0.phys_addr >> 24) != 0x20) {
487 printk("jsflash: suspicious address: 0x%x:%x\n",
488 reg0.which_io, reg0.phys_addr);
489 return -ENXIO;
490 }
491 #endif
492 if ((int)reg0.reg_size <= 0) {
493 printk("jsflash: bad size 0x%x\n", (int)reg0.reg_size);
494 return -ENXIO;
495 }
496 } else {
497 /* XXX Remove this code once PROLL ID12 got widespread */
498 printk("jsflash: no /flash-memory node, use PROLL >= 12\n");
499 prom_getproperty(prom_root_node, "banner-name", banner, 128);
500 if (strcmp (banner, "JavaStation-NC") != 0 &&
501 strcmp (banner, "JavaStation-E") != 0) {
502 return -ENXIO;
503 }
504 reg0.which_io = 0;
505 reg0.phys_addr = 0x20400000;
506 reg0.reg_size = 0x00800000;
507 }
508
509 /* Let us be really paranoid for modifications to probing code. */
510 /* extern enum sparc_cpu sparc_cpu_model; */ /* in <asm/system.h> */
511 if (sparc_cpu_model != sun4m) {
512 /* We must be on sun4m because we use MMU Bypass ASI. */
513 return -ENXIO;
514 }
515
516 if (jsf0.base == 0) {
517 jsf = &jsf0;
518
519 jsf->base = reg0.phys_addr;
520 jsf->size = reg0.reg_size;
521
522 /* XXX Redo the userland interface. */
523 jsf->id.off = JSF_BASE_ALL;
524 jsf->id.size = 0x01000000; /* 16M - all segments */
525 strcpy(jsf->id.name, "Krups_all");
526
527 jsf->dv[0].dbase = jsf->base;
528 jsf->dv[0].dsize = jsf->size;
529 jsf->dv[1].dbase = jsf->base + 1024;
530 jsf->dv[1].dsize = jsf->size - 1024;
531 jsf->dv[2].dbase = JSF_BASE_ALL;
532 jsf->dv[2].dsize = 0x01000000;
533
534 printk("Espresso Flash @0x%lx [%d MB]\n", jsf->base,
535 (int) (jsf->size / (1024*1024)));
536 }
537
538 if ((rc = misc_register(&jsf_dev)) != 0) {
539 printk(KERN_ERR "jsf: unable to get misc minor %d\n",
540 JSF_MINOR);
541 jsf0.base = 0;
542 return rc;
543 }
544
545 return 0;
546 }
547
548 static struct request_queue *jsf_queue;
549
jsfd_init(void)550 static int jsfd_init(void)
551 {
552 static DEFINE_SPINLOCK(lock);
553 struct jsflash *jsf;
554 struct jsfd_part *jdp;
555 int err;
556 int i;
557
558 if (jsf0.base == 0)
559 return -ENXIO;
560
561 err = -ENOMEM;
562 for (i = 0; i < JSF_MAX; i++) {
563 struct gendisk *disk = alloc_disk(1);
564 if (!disk)
565 goto out;
566 jsfd_disk[i] = disk;
567 }
568
569 if (register_blkdev(JSFD_MAJOR, "jsfd")) {
570 err = -EIO;
571 goto out;
572 }
573
574 jsf_queue = blk_init_queue(jsfd_do_request, &lock);
575 if (!jsf_queue) {
576 err = -ENOMEM;
577 unregister_blkdev(JSFD_MAJOR, "jsfd");
578 goto out;
579 }
580
581 for (i = 0; i < JSF_MAX; i++) {
582 struct gendisk *disk = jsfd_disk[i];
583 if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
584 jsf = &jsf0; /* actually, &jsfv[i >> JSF_PART_BITS] */
585 jdp = &jsf->dv[i&JSF_PART_MASK];
586
587 disk->major = JSFD_MAJOR;
588 disk->first_minor = i;
589 sprintf(disk->disk_name, "jsfd%d", i);
590 disk->fops = &jsfd_fops;
591 set_capacity(disk, jdp->dsize >> 9);
592 disk->private_data = jdp;
593 disk->queue = jsf_queue;
594 add_disk(disk);
595 set_disk_ro(disk, 1);
596 }
597 return 0;
598 out:
599 while (i--)
600 put_disk(jsfd_disk[i]);
601 return err;
602 }
603
604 MODULE_LICENSE("GPL");
605
jsflash_init_module(void)606 static int __init jsflash_init_module(void) {
607 int rc;
608
609 if ((rc = jsflash_init()) == 0) {
610 jsfd_init();
611 return 0;
612 }
613 return rc;
614 }
615
jsflash_cleanup_module(void)616 static void __exit jsflash_cleanup_module(void)
617 {
618 int i;
619
620 for (i = 0; i < JSF_MAX; i++) {
621 if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
622 del_gendisk(jsfd_disk[i]);
623 put_disk(jsfd_disk[i]);
624 }
625 if (jsf0.busy)
626 printk("jsf0: cleaning busy unit\n");
627 jsf0.base = 0;
628 jsf0.busy = 0;
629
630 misc_deregister(&jsf_dev);
631 unregister_blkdev(JSFD_MAJOR, "jsfd");
632 blk_cleanup_queue(jsf_queue);
633 }
634
635 module_init(jsflash_init_module);
636 module_exit(jsflash_cleanup_module);
637