ia64/linux-2.6.18-xen.hg

view arch/mips/kernel/rtlx.c @ 452:c7ed6fe5dca0

kexec: dont initialise regions in reserve_memory()

There is no need to initialise efi_memmap_res and boot_param_res in
reserve_memory() for the initial xen domain as it is done in
machine_kexec_setup_resources() using values from the kexec hypercall.

Signed-off-by: Simon Horman <horms@verge.net.au>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Feb 28 10:55:18 2008 +0000 (2008-02-28)
parents 831230e53067
children
line source
1 /*
2 * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
3 * Copyright (C) 2005, 06 Ralf Baechle (ralf@linux-mips.org)
4 *
5 * This program is free software; you can distribute it and/or modify it
6 * under the terms of the GNU General Public License (Version 2) as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
17 *
18 */
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/fs.h>
23 #include <linux/init.h>
24 #include <asm/uaccess.h>
25 #include <linux/slab.h>
26 #include <linux/list.h>
27 #include <linux/vmalloc.h>
28 #include <linux/elf.h>
29 #include <linux/seq_file.h>
30 #include <linux/syscalls.h>
31 #include <linux/moduleloader.h>
32 #include <linux/interrupt.h>
33 #include <linux/poll.h>
34 #include <linux/sched.h>
35 #include <linux/wait.h>
36 #include <asm/mipsmtregs.h>
37 #include <asm/cacheflush.h>
38 #include <asm/atomic.h>
39 #include <asm/cpu.h>
40 #include <asm/processor.h>
41 #include <asm/system.h>
42 #include <asm/vpe.h>
43 #include <asm/rtlx.h>
45 #define RTLX_TARG_VPE 1
47 static struct rtlx_info *rtlx;
48 static int major;
49 static char module_name[] = "rtlx";
51 static struct chan_waitqueues {
52 wait_queue_head_t rt_queue;
53 wait_queue_head_t lx_queue;
54 int in_open;
55 } channel_wqs[RTLX_CHANNELS];
57 static struct irqaction irq;
58 static int irq_num;
59 static struct vpe_notifications notify;
60 static int sp_stopping = 0;
62 extern void *vpe_get_shared(int index);
64 static void rtlx_dispatch(struct pt_regs *regs)
65 {
66 do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_RTLX_IRQ, regs);
67 }
70 /* Interrupt handler may be called before rtlx_init has otherwise had
71 a chance to run.
72 */
73 static irqreturn_t rtlx_interrupt(int irq, void *dev_id, struct pt_regs *regs)
74 {
75 int i;
77 for (i = 0; i < RTLX_CHANNELS; i++) {
78 wake_up(&channel_wqs[i].lx_queue);
79 wake_up(&channel_wqs[i].rt_queue);
80 }
82 return IRQ_HANDLED;
83 }
85 static __attribute_used__ void dump_rtlx(void)
86 {
87 int i;
89 printk("id 0x%lx state %d\n", rtlx->id, rtlx->state);
91 for (i = 0; i < RTLX_CHANNELS; i++) {
92 struct rtlx_channel *chan = &rtlx->channel[i];
94 printk(" rt_state %d lx_state %d buffer_size %d\n",
95 chan->rt_state, chan->lx_state, chan->buffer_size);
97 printk(" rt_read %d rt_write %d\n",
98 chan->rt_read, chan->rt_write);
100 printk(" lx_read %d lx_write %d\n",
101 chan->lx_read, chan->lx_write);
103 printk(" rt_buffer <%s>\n", chan->rt_buffer);
104 printk(" lx_buffer <%s>\n", chan->lx_buffer);
105 }
106 }
108 /* call when we have the address of the shared structure from the SP side. */
109 static int rtlx_init(struct rtlx_info *rtlxi)
110 {
111 if (rtlxi->id != RTLX_ID) {
112 printk(KERN_ERR "no valid RTLX id at 0x%p 0x%x\n", rtlxi, rtlxi->id);
113 return -ENOEXEC;
114 }
116 rtlx = rtlxi;
118 return 0;
119 }
121 /* notifications */
122 static void starting(int vpe)
123 {
124 int i;
125 sp_stopping = 0;
127 /* force a reload of rtlx */
128 rtlx=NULL;
130 /* wake up any sleeping rtlx_open's */
131 for (i = 0; i < RTLX_CHANNELS; i++)
132 wake_up_interruptible(&channel_wqs[i].lx_queue);
133 }
135 static void stopping(int vpe)
136 {
137 int i;
139 sp_stopping = 1;
140 for (i = 0; i < RTLX_CHANNELS; i++)
141 wake_up_interruptible(&channel_wqs[i].lx_queue);
142 }
145 int rtlx_open(int index, int can_sleep)
146 {
147 int ret;
148 struct rtlx_channel *chan;
149 volatile struct rtlx_info **p;
151 if (index >= RTLX_CHANNELS) {
152 printk(KERN_DEBUG "rtlx_open index out of range\n");
153 return -ENOSYS;
154 }
156 if (channel_wqs[index].in_open) {
157 printk(KERN_DEBUG "rtlx_open channel %d already opened\n", index);
158 return -EBUSY;
159 }
161 channel_wqs[index].in_open++;
163 if (rtlx == NULL) {
164 if( (p = vpe_get_shared(RTLX_TARG_VPE)) == NULL) {
165 if (can_sleep) {
166 DECLARE_WAITQUEUE(wait, current);
168 /* go to sleep */
169 add_wait_queue(&channel_wqs[index].lx_queue, &wait);
171 set_current_state(TASK_INTERRUPTIBLE);
172 while ((p = vpe_get_shared(RTLX_TARG_VPE)) == NULL) {
173 schedule();
174 set_current_state(TASK_INTERRUPTIBLE);
175 }
177 set_current_state(TASK_RUNNING);
178 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
180 /* back running */
181 } else {
182 printk( KERN_DEBUG "No SP program loaded, and device "
183 "opened with O_NONBLOCK\n");
184 channel_wqs[index].in_open = 0;
185 return -ENOSYS;
186 }
187 }
189 if (*p == NULL) {
190 if (can_sleep) {
191 DECLARE_WAITQUEUE(wait, current);
193 /* go to sleep */
194 add_wait_queue(&channel_wqs[index].lx_queue, &wait);
196 set_current_state(TASK_INTERRUPTIBLE);
197 while (*p == NULL) {
198 schedule();
200 /* reset task state to interruptable otherwise
201 we'll whizz round here like a very fast loopy
202 thing. schedule() appears to return with state
203 set to TASK_RUNNING.
205 If the loaded SP program, for whatever reason,
206 doesn't set up the shared structure *p will never
207 become true. So whoever connected to either /dev/rt?
208 or if it was kspd, will then take up rather a lot of
209 processor cycles.
210 */
212 set_current_state(TASK_INTERRUPTIBLE);
213 }
215 set_current_state(TASK_RUNNING);
216 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
218 /* back running */
219 }
220 else {
221 printk(" *vpe_get_shared is NULL. "
222 "Has an SP program been loaded?\n");
223 channel_wqs[index].in_open = 0;
224 return -ENOSYS;
225 }
226 }
228 if ((unsigned int)*p < KSEG0) {
229 printk(KERN_WARNING "vpe_get_shared returned an invalid pointer "
230 "maybe an error code %d\n", (int)*p);
231 channel_wqs[index].in_open = 0;
232 return -ENOSYS;
233 }
235 if ((ret = rtlx_init(*p)) < 0) {
236 channel_wqs[index].in_open = 0;
237 return ret;
238 }
239 }
241 chan = &rtlx->channel[index];
243 if (chan->lx_state == RTLX_STATE_OPENED) {
244 channel_wqs[index].in_open = 0;
245 return -EBUSY;
246 }
248 chan->lx_state = RTLX_STATE_OPENED;
249 channel_wqs[index].in_open = 0;
250 return 0;
251 }
253 int rtlx_release(int index)
254 {
255 rtlx->channel[index].lx_state = RTLX_STATE_UNUSED;
256 return 0;
257 }
259 unsigned int rtlx_read_poll(int index, int can_sleep)
260 {
261 struct rtlx_channel *chan;
263 if (rtlx == NULL)
264 return 0;
266 chan = &rtlx->channel[index];
268 /* data available to read? */
269 if (chan->lx_read == chan->lx_write) {
270 if (can_sleep) {
271 DECLARE_WAITQUEUE(wait, current);
273 /* go to sleep */
274 add_wait_queue(&channel_wqs[index].lx_queue, &wait);
276 set_current_state(TASK_INTERRUPTIBLE);
277 while (chan->lx_read == chan->lx_write) {
278 schedule();
280 set_current_state(TASK_INTERRUPTIBLE);
282 if (sp_stopping) {
283 set_current_state(TASK_RUNNING);
284 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
285 return 0;
286 }
287 }
289 set_current_state(TASK_RUNNING);
290 remove_wait_queue(&channel_wqs[index].lx_queue, &wait);
292 /* back running */
293 }
294 else
295 return 0;
296 }
298 return (chan->lx_write + chan->buffer_size - chan->lx_read)
299 % chan->buffer_size;
300 }
302 static inline int write_spacefree(int read, int write, int size)
303 {
304 if (read == write) {
305 /*
306 * Never fill the buffer completely, so indexes are always
307 * equal if empty and only empty, or !equal if data available
308 */
309 return size - 1;
310 }
312 return ((read + size - write) % size) - 1;
313 }
315 unsigned int rtlx_write_poll(int index)
316 {
317 struct rtlx_channel *chan = &rtlx->channel[index];
318 return write_spacefree(chan->rt_read, chan->rt_write, chan->buffer_size);
319 }
321 static inline void copy_to(void *dst, void *src, size_t count, int user)
322 {
323 if (user)
324 copy_to_user(dst, src, count);
325 else
326 memcpy(dst, src, count);
327 }
329 static inline void copy_from(void *dst, void *src, size_t count, int user)
330 {
331 if (user)
332 copy_from_user(dst, src, count);
333 else
334 memcpy(dst, src, count);
335 }
337 ssize_t rtlx_read(int index, void *buff, size_t count, int user)
338 {
339 size_t fl = 0L;
340 struct rtlx_channel *lx;
342 if (rtlx == NULL)
343 return -ENOSYS;
345 lx = &rtlx->channel[index];
347 /* find out how much in total */
348 count = min(count,
349 (size_t)(lx->lx_write + lx->buffer_size - lx->lx_read)
350 % lx->buffer_size);
352 /* then how much from the read pointer onwards */
353 fl = min( count, (size_t)lx->buffer_size - lx->lx_read);
355 copy_to(buff, &lx->lx_buffer[lx->lx_read], fl, user);
357 /* and if there is anything left at the beginning of the buffer */
358 if ( count - fl )
359 copy_to (buff + fl, lx->lx_buffer, count - fl, user);
361 /* update the index */
362 lx->lx_read += count;
363 lx->lx_read %= lx->buffer_size;
365 return count;
366 }
368 ssize_t rtlx_write(int index, void *buffer, size_t count, int user)
369 {
370 struct rtlx_channel *rt;
371 size_t fl;
373 if (rtlx == NULL)
374 return(-ENOSYS);
376 rt = &rtlx->channel[index];
378 /* total number of bytes to copy */
379 count = min(count,
380 (size_t)write_spacefree(rt->rt_read, rt->rt_write,
381 rt->buffer_size));
383 /* first bit from write pointer to the end of the buffer, or count */
384 fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
386 copy_from (&rt->rt_buffer[rt->rt_write], buffer, fl, user);
388 /* if there's any left copy to the beginning of the buffer */
389 if( count - fl )
390 copy_from (rt->rt_buffer, buffer + fl, count - fl, user);
392 rt->rt_write += count;
393 rt->rt_write %= rt->buffer_size;
395 return(count);
396 }
399 static int file_open(struct inode *inode, struct file *filp)
400 {
401 int minor = iminor(inode);
403 return rtlx_open(minor, (filp->f_flags & O_NONBLOCK) ? 0 : 1);
404 }
406 static int file_release(struct inode *inode, struct file *filp)
407 {
408 int minor = iminor(inode);
410 return rtlx_release(minor);
411 }
413 static unsigned int file_poll(struct file *file, poll_table * wait)
414 {
415 int minor;
416 unsigned int mask = 0;
418 minor = iminor(file->f_dentry->d_inode);
420 poll_wait(file, &channel_wqs[minor].rt_queue, wait);
421 poll_wait(file, &channel_wqs[minor].lx_queue, wait);
423 if (rtlx == NULL)
424 return 0;
426 /* data available to read? */
427 if (rtlx_read_poll(minor, 0))
428 mask |= POLLIN | POLLRDNORM;
430 /* space to write */
431 if (rtlx_write_poll(minor))
432 mask |= POLLOUT | POLLWRNORM;
434 return mask;
435 }
437 static ssize_t file_read(struct file *file, char __user * buffer, size_t count,
438 loff_t * ppos)
439 {
440 int minor = iminor(file->f_dentry->d_inode);
442 /* data available? */
443 if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1)) {
444 return 0; // -EAGAIN makes cat whinge
445 }
447 return rtlx_read(minor, buffer, count, 1);
448 }
450 static ssize_t file_write(struct file *file, const char __user * buffer,
451 size_t count, loff_t * ppos)
452 {
453 int minor;
454 struct rtlx_channel *rt;
455 DECLARE_WAITQUEUE(wait, current);
457 minor = iminor(file->f_dentry->d_inode);
458 rt = &rtlx->channel[minor];
460 /* any space left... */
461 if (!rtlx_write_poll(minor)) {
463 if (file->f_flags & O_NONBLOCK)
464 return -EAGAIN;
466 add_wait_queue(&channel_wqs[minor].rt_queue, &wait);
467 set_current_state(TASK_INTERRUPTIBLE);
469 while (!rtlx_write_poll(minor))
470 schedule();
472 set_current_state(TASK_RUNNING);
473 remove_wait_queue(&channel_wqs[minor].rt_queue, &wait);
474 }
476 return rtlx_write(minor, (void *)buffer, count, 1);
477 }
479 static struct file_operations rtlx_fops = {
480 .owner = THIS_MODULE,
481 .open = file_open,
482 .release = file_release,
483 .write = file_write,
484 .read = file_read,
485 .poll = file_poll
486 };
488 static struct irqaction rtlx_irq = {
489 .handler = rtlx_interrupt,
490 .flags = IRQF_DISABLED,
491 .name = "RTLX",
492 };
494 static int rtlx_irq_num = MIPSCPU_INT_BASE + MIPS_CPU_RTLX_IRQ;
496 static char register_chrdev_failed[] __initdata =
497 KERN_ERR "rtlx_module_init: unable to register device\n";
499 static int rtlx_module_init(void)
500 {
501 int i;
503 major = register_chrdev(0, module_name, &rtlx_fops);
504 if (major < 0) {
505 printk(register_chrdev_failed);
506 return major;
507 }
509 /* initialise the wait queues */
510 for (i = 0; i < RTLX_CHANNELS; i++) {
511 init_waitqueue_head(&channel_wqs[i].rt_queue);
512 init_waitqueue_head(&channel_wqs[i].lx_queue);
513 channel_wqs[i].in_open = 0;
514 }
516 /* set up notifiers */
517 notify.start = starting;
518 notify.stop = stopping;
519 vpe_notify(RTLX_TARG_VPE, &notify);
521 if (cpu_has_vint)
522 set_vi_handler(MIPS_CPU_RTLX_IRQ, rtlx_dispatch);
524 rtlx_irq.dev_id = rtlx;
525 setup_irq(rtlx_irq_num, &rtlx_irq);
527 return 0;
528 }
530 static void __exit rtlx_module_exit(void)
531 {
532 unregister_chrdev(major, module_name);
533 }
535 module_init(rtlx_module_init);
536 module_exit(rtlx_module_exit);
538 MODULE_DESCRIPTION("MIPS RTLX");
539 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
540 MODULE_LICENSE("GPL");