2 * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
3 * Copyright (C) 2005, 06 Ralf Baechle (ralf@linux-mips.org)
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.
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
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.
20 #include <linux/device.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <asm/uaccess.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/mips_mt.h>
38 #include <asm/cacheflush.h>
39 #include <asm/atomic.h>
41 #include <asm/processor.h>
42 #include <asm/system.h>
46 static struct rtlx_info *rtlx;
48 static char module_name[] = "rtlx";
50 static struct chan_waitqueues {
51 wait_queue_head_t rt_queue;
52 wait_queue_head_t lx_queue;
55 } channel_wqs[RTLX_CHANNELS];
57 static struct vpe_notifications notify;
58 static int sp_stopping;
60 extern void *vpe_get_shared(int index);
62 static void rtlx_dispatch(void)
64 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
68 /* Interrupt handler may be called before rtlx_init has otherwise had
71 static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
73 unsigned int vpeflags;
77 /* Ought not to be strictly necessary for SMTC builds */
78 local_irq_save(flags);
80 set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
83 local_irq_restore(flags);
85 for (i = 0; i < RTLX_CHANNELS; i++) {
86 wake_up(&channel_wqs[i].lx_queue);
87 wake_up(&channel_wqs[i].rt_queue);
93 static void __used dump_rtlx(void)
97 printk("id 0x%lx state %d\n", rtlx->id, rtlx->state);
99 for (i = 0; i < RTLX_CHANNELS; i++) {
100 struct rtlx_channel *chan = &rtlx->channel[i];
102 printk(" rt_state %d lx_state %d buffer_size %d\n",
103 chan->rt_state, chan->lx_state, chan->buffer_size);
105 printk(" rt_read %d rt_write %d\n",
106 chan->rt_read, chan->rt_write);
108 printk(" lx_read %d lx_write %d\n",
109 chan->lx_read, chan->lx_write);
111 printk(" rt_buffer <%s>\n", chan->rt_buffer);
112 printk(" lx_buffer <%s>\n", chan->lx_buffer);
116 /* call when we have the address of the shared structure from the SP side. */
117 static int rtlx_init(struct rtlx_info *rtlxi)
119 if (rtlxi->id != RTLX_ID) {
120 printk(KERN_ERR "no valid RTLX id at 0x%p 0x%lx\n",
131 static void starting(int vpe)
136 /* force a reload of rtlx */
139 /* wake up any sleeping rtlx_open's */
140 for (i = 0; i < RTLX_CHANNELS; i++)
141 wake_up_interruptible(&channel_wqs[i].lx_queue);
144 static void stopping(int vpe)
149 for (i = 0; i < RTLX_CHANNELS; i++)
150 wake_up_interruptible(&channel_wqs[i].lx_queue);
154 int rtlx_open(int index, int can_sleep)
156 struct rtlx_info **p;
157 struct rtlx_channel *chan;
158 enum rtlx_state state;
161 if (index >= RTLX_CHANNELS) {
162 printk(KERN_DEBUG "rtlx_open index out of range\n");
166 if (atomic_inc_return(&channel_wqs[index].in_open) > 1) {
167 printk(KERN_DEBUG "rtlx_open channel %d already opened\n",
174 if( (p = vpe_get_shared(tclimit)) == NULL) {
176 __wait_event_interruptible(channel_wqs[index].lx_queue,
177 (p = vpe_get_shared(tclimit)), ret);
181 printk(KERN_DEBUG "No SP program loaded, and device "
182 "opened with O_NONBLOCK\n");
195 &channel_wqs[index].lx_queue,
196 &wait, TASK_INTERRUPTIBLE);
200 if (!signal_pending(current)) {
207 finish_wait(&channel_wqs[index].lx_queue, &wait);
209 pr_err(" *vpe_get_shared is NULL. "
210 "Has an SP program been loaded?\n");
216 if ((unsigned int)*p < KSEG0) {
217 printk(KERN_WARNING "vpe_get_shared returned an "
218 "invalid pointer maybe an error code %d\n",
224 if ((ret = rtlx_init(*p)) < 0)
228 chan = &rtlx->channel[index];
230 state = xchg(&chan->lx_state, RTLX_STATE_OPENED);
231 if (state == RTLX_STATE_OPENED) {
238 atomic_dec(&channel_wqs[index].in_open);
245 int rtlx_release(int index)
248 pr_err("rtlx_release() with null rtlx\n");
251 rtlx->channel[index].lx_state = RTLX_STATE_UNUSED;
255 unsigned int rtlx_read_poll(int index, int can_sleep)
257 struct rtlx_channel *chan;
262 chan = &rtlx->channel[index];
264 /* data available to read? */
265 if (chan->lx_read == chan->lx_write) {
269 __wait_event_interruptible(channel_wqs[index].lx_queue,
270 (chan->lx_read != chan->lx_write) ||
281 return (chan->lx_write + chan->buffer_size - chan->lx_read)
285 static inline int write_spacefree(int read, int write, int size)
289 * Never fill the buffer completely, so indexes are always
290 * equal if empty and only empty, or !equal if data available
295 return ((read + size - write) % size) - 1;
298 unsigned int rtlx_write_poll(int index)
300 struct rtlx_channel *chan = &rtlx->channel[index];
302 return write_spacefree(chan->rt_read, chan->rt_write,
306 ssize_t rtlx_read(int index, void __user *buff, size_t count)
308 size_t lx_write, fl = 0L;
309 struct rtlx_channel *lx;
310 unsigned long failed;
315 lx = &rtlx->channel[index];
317 mutex_lock(&channel_wqs[index].mutex);
319 lx_write = lx->lx_write;
321 /* find out how much in total */
323 (size_t)(lx_write + lx->buffer_size - lx->lx_read)
326 /* then how much from the read pointer onwards */
327 fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
329 failed = copy_to_user(buff, lx->lx_buffer + lx->lx_read, fl);
333 /* and if there is anything left at the beginning of the buffer */
335 failed = copy_to_user(buff + fl, lx->lx_buffer, count - fl);
341 lx->lx_read = (lx->lx_read + count) % lx->buffer_size;
343 mutex_unlock(&channel_wqs[index].mutex);
348 ssize_t rtlx_write(int index, const void __user *buffer, size_t count)
350 struct rtlx_channel *rt;
351 unsigned long failed;
358 rt = &rtlx->channel[index];
360 mutex_lock(&channel_wqs[index].mutex);
362 rt_read = rt->rt_read;
364 /* total number of bytes to copy */
365 count = min(count, (size_t)write_spacefree(rt_read, rt->rt_write,
368 /* first bit from write pointer to the end of the buffer, or count */
369 fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
371 failed = copy_from_user(rt->rt_buffer + rt->rt_write, buffer, fl);
375 /* if there's any left copy to the beginning of the buffer */
377 failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
384 rt->rt_write = (rt->rt_write + count) % rt->buffer_size;
386 mutex_unlock(&channel_wqs[index].mutex);
392 static int file_open(struct inode *inode, struct file *filp)
394 return rtlx_open(iminor(inode), (filp->f_flags & O_NONBLOCK) ? 0 : 1);
397 static int file_release(struct inode *inode, struct file *filp)
399 return rtlx_release(iminor(inode));
402 static unsigned int file_poll(struct file *file, poll_table * wait)
405 unsigned int mask = 0;
407 minor = iminor(file->f_path.dentry->d_inode);
409 poll_wait(file, &channel_wqs[minor].rt_queue, wait);
410 poll_wait(file, &channel_wqs[minor].lx_queue, wait);
415 /* data available to read? */
416 if (rtlx_read_poll(minor, 0))
417 mask |= POLLIN | POLLRDNORM;
420 if (rtlx_write_poll(minor))
421 mask |= POLLOUT | POLLWRNORM;
426 static ssize_t file_read(struct file *file, char __user * buffer, size_t count,
429 int minor = iminor(file->f_path.dentry->d_inode);
431 /* data available? */
432 if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1)) {
433 return 0; // -EAGAIN makes cat whinge
436 return rtlx_read(minor, buffer, count);
439 static ssize_t file_write(struct file *file, const char __user * buffer,
440 size_t count, loff_t * ppos)
443 struct rtlx_channel *rt;
445 minor = iminor(file->f_path.dentry->d_inode);
446 rt = &rtlx->channel[minor];
448 /* any space left... */
449 if (!rtlx_write_poll(minor)) {
452 if (file->f_flags & O_NONBLOCK)
455 __wait_event_interruptible(channel_wqs[minor].rt_queue,
456 rtlx_write_poll(minor),
462 return rtlx_write(minor, buffer, count);
465 static const struct file_operations rtlx_fops = {
466 .owner = THIS_MODULE,
468 .release = file_release,
472 .llseek = noop_llseek,
475 static struct irqaction rtlx_irq = {
476 .handler = rtlx_interrupt,
477 .flags = IRQF_DISABLED,
481 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
483 static char register_chrdev_failed[] __initdata =
484 KERN_ERR "rtlx_module_init: unable to register device\n";
486 static int __init rtlx_module_init(void)
491 if (!cpu_has_mipsmt) {
492 printk("VPE loader: not a MIPS MT capable processor\n");
497 printk(KERN_WARNING "No TCs reserved for AP/SP, not "
498 "initializing RTLX.\nPass maxtcs=<n> argument as kernel "
504 major = register_chrdev(0, module_name, &rtlx_fops);
506 printk(register_chrdev_failed);
510 /* initialise the wait queues */
511 for (i = 0; i < RTLX_CHANNELS; i++) {
512 init_waitqueue_head(&channel_wqs[i].rt_queue);
513 init_waitqueue_head(&channel_wqs[i].lx_queue);
514 atomic_set(&channel_wqs[i].in_open, 0);
515 mutex_init(&channel_wqs[i].mutex);
517 dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
518 "%s%d", module_name, i);
525 /* set up notifiers */
526 notify.start = starting;
527 notify.stop = stopping;
528 vpe_notify(tclimit, ¬ify);
531 set_vi_handler(MIPS_CPU_RTLX_IRQ, rtlx_dispatch);
533 pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
538 rtlx_irq.dev_id = rtlx;
539 setup_irq(rtlx_irq_num, &rtlx_irq);
544 for (i = 0; i < RTLX_CHANNELS; i++)
545 device_destroy(mt_class, MKDEV(major, i));
550 static void __exit rtlx_module_exit(void)
554 for (i = 0; i < RTLX_CHANNELS; i++)
555 device_destroy(mt_class, MKDEV(major, i));
557 unregister_chrdev(major, module_name);
560 module_init(rtlx_module_init);
561 module_exit(rtlx_module_exit);
563 MODULE_DESCRIPTION("MIPS RTLX");
564 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
565 MODULE_LICENSE("GPL");