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/slab.h>
27 #include <linux/list.h>
28 #include <linux/vmalloc.h>
29 #include <linux/elf.h>
30 #include <linux/seq_file.h>
31 #include <linux/smp_lock.h>
32 #include <linux/syscalls.h>
33 #include <linux/moduleloader.h>
34 #include <linux/interrupt.h>
35 #include <linux/poll.h>
36 #include <linux/sched.h>
37 #include <linux/wait.h>
38 #include <asm/mipsmtregs.h>
39 #include <asm/mips_mt.h>
40 #include <asm/cacheflush.h>
41 #include <asm/atomic.h>
43 #include <asm/processor.h>
44 #include <asm/system.h>
48 static struct rtlx_info *rtlx;
50 static char module_name[] = "rtlx";
52 static struct chan_waitqueues {
53 wait_queue_head_t rt_queue;
54 wait_queue_head_t lx_queue;
57 } channel_wqs[RTLX_CHANNELS];
59 static struct vpe_notifications notify;
60 static int sp_stopping;
62 extern void *vpe_get_shared(int index);
64 static void rtlx_dispatch(void)
66 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
70 /* Interrupt handler may be called before rtlx_init has otherwise had
73 static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
75 unsigned int vpeflags;
79 /* Ought not to be strictly necessary for SMTC builds */
80 local_irq_save(flags);
82 set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
85 local_irq_restore(flags);
87 for (i = 0; i < RTLX_CHANNELS; i++) {
88 wake_up(&channel_wqs[i].lx_queue);
89 wake_up(&channel_wqs[i].rt_queue);
95 static void __used dump_rtlx(void)
99 printk("id 0x%lx state %d\n", rtlx->id, rtlx->state);
101 for (i = 0; i < RTLX_CHANNELS; i++) {
102 struct rtlx_channel *chan = &rtlx->channel[i];
104 printk(" rt_state %d lx_state %d buffer_size %d\n",
105 chan->rt_state, chan->lx_state, chan->buffer_size);
107 printk(" rt_read %d rt_write %d\n",
108 chan->rt_read, chan->rt_write);
110 printk(" lx_read %d lx_write %d\n",
111 chan->lx_read, chan->lx_write);
113 printk(" rt_buffer <%s>\n", chan->rt_buffer);
114 printk(" lx_buffer <%s>\n", chan->lx_buffer);
118 /* call when we have the address of the shared structure from the SP side. */
119 static int rtlx_init(struct rtlx_info *rtlxi)
121 if (rtlxi->id != RTLX_ID) {
122 printk(KERN_ERR "no valid RTLX id at 0x%p 0x%lx\n",
133 static void starting(int vpe)
138 /* force a reload of rtlx */
141 /* wake up any sleeping rtlx_open's */
142 for (i = 0; i < RTLX_CHANNELS; i++)
143 wake_up_interruptible(&channel_wqs[i].lx_queue);
146 static void stopping(int vpe)
151 for (i = 0; i < RTLX_CHANNELS; i++)
152 wake_up_interruptible(&channel_wqs[i].lx_queue);
156 int rtlx_open(int index, int can_sleep)
158 struct rtlx_info **p;
159 struct rtlx_channel *chan;
160 enum rtlx_state state;
163 if (index >= RTLX_CHANNELS) {
164 printk(KERN_DEBUG "rtlx_open index out of range\n");
168 if (atomic_inc_return(&channel_wqs[index].in_open) > 1) {
169 printk(KERN_DEBUG "rtlx_open channel %d already opened\n",
176 if( (p = vpe_get_shared(tclimit)) == NULL) {
178 __wait_event_interruptible(channel_wqs[index].lx_queue,
179 (p = vpe_get_shared(tclimit)), ret);
183 printk(KERN_DEBUG "No SP program loaded, and device "
184 "opened with O_NONBLOCK\n");
197 &channel_wqs[index].lx_queue,
198 &wait, TASK_INTERRUPTIBLE);
202 if (!signal_pending(current)) {
209 finish_wait(&channel_wqs[index].lx_queue, &wait);
211 pr_err(" *vpe_get_shared is NULL. "
212 "Has an SP program been loaded?\n");
218 if ((unsigned int)*p < KSEG0) {
219 printk(KERN_WARNING "vpe_get_shared returned an "
220 "invalid pointer maybe an error code %d\n",
226 if ((ret = rtlx_init(*p)) < 0)
230 chan = &rtlx->channel[index];
232 state = xchg(&chan->lx_state, RTLX_STATE_OPENED);
233 if (state == RTLX_STATE_OPENED) {
240 atomic_dec(&channel_wqs[index].in_open);
247 int rtlx_release(int index)
250 pr_err("rtlx_release() with null rtlx\n");
253 rtlx->channel[index].lx_state = RTLX_STATE_UNUSED;
257 unsigned int rtlx_read_poll(int index, int can_sleep)
259 struct rtlx_channel *chan;
264 chan = &rtlx->channel[index];
266 /* data available to read? */
267 if (chan->lx_read == chan->lx_write) {
271 __wait_event_interruptible(channel_wqs[index].lx_queue,
272 (chan->lx_read != chan->lx_write) ||
283 return (chan->lx_write + chan->buffer_size - chan->lx_read)
287 static inline int write_spacefree(int read, int write, int size)
291 * Never fill the buffer completely, so indexes are always
292 * equal if empty and only empty, or !equal if data available
297 return ((read + size - write) % size) - 1;
300 unsigned int rtlx_write_poll(int index)
302 struct rtlx_channel *chan = &rtlx->channel[index];
304 return write_spacefree(chan->rt_read, chan->rt_write,
308 ssize_t rtlx_read(int index, void __user *buff, size_t count)
310 size_t lx_write, fl = 0L;
311 struct rtlx_channel *lx;
312 unsigned long failed;
317 lx = &rtlx->channel[index];
319 mutex_lock(&channel_wqs[index].mutex);
321 lx_write = lx->lx_write;
323 /* find out how much in total */
325 (size_t)(lx_write + lx->buffer_size - lx->lx_read)
328 /* then how much from the read pointer onwards */
329 fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
331 failed = copy_to_user(buff, lx->lx_buffer + lx->lx_read, fl);
335 /* and if there is anything left at the beginning of the buffer */
337 failed = copy_to_user(buff + fl, lx->lx_buffer, count - fl);
343 lx->lx_read = (lx->lx_read + count) % lx->buffer_size;
345 mutex_unlock(&channel_wqs[index].mutex);
350 ssize_t rtlx_write(int index, const void __user *buffer, size_t count)
352 struct rtlx_channel *rt;
353 unsigned long failed;
360 rt = &rtlx->channel[index];
362 mutex_lock(&channel_wqs[index].mutex);
364 rt_read = rt->rt_read;
366 /* total number of bytes to copy */
367 count = min(count, (size_t)write_spacefree(rt_read, rt->rt_write,
370 /* first bit from write pointer to the end of the buffer, or count */
371 fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
373 failed = copy_from_user(rt->rt_buffer + rt->rt_write, buffer, fl);
377 /* if there's any left copy to the beginning of the buffer */
379 failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
386 rt->rt_write = (rt->rt_write + count) % rt->buffer_size;
388 mutex_unlock(&channel_wqs[index].mutex);
394 static int file_open(struct inode *inode, struct file *filp)
396 return rtlx_open(iminor(inode), (filp->f_flags & O_NONBLOCK) ? 0 : 1);
399 static int file_release(struct inode *inode, struct file *filp)
401 return rtlx_release(iminor(inode));
404 static unsigned int file_poll(struct file *file, poll_table * wait)
407 unsigned int mask = 0;
409 minor = iminor(file->f_path.dentry->d_inode);
411 poll_wait(file, &channel_wqs[minor].rt_queue, wait);
412 poll_wait(file, &channel_wqs[minor].lx_queue, wait);
417 /* data available to read? */
418 if (rtlx_read_poll(minor, 0))
419 mask |= POLLIN | POLLRDNORM;
422 if (rtlx_write_poll(minor))
423 mask |= POLLOUT | POLLWRNORM;
428 static ssize_t file_read(struct file *file, char __user * buffer, size_t count,
431 int minor = iminor(file->f_path.dentry->d_inode);
433 /* data available? */
434 if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1)) {
435 return 0; // -EAGAIN makes cat whinge
438 return rtlx_read(minor, buffer, count);
441 static ssize_t file_write(struct file *file, const char __user * buffer,
442 size_t count, loff_t * ppos)
445 struct rtlx_channel *rt;
447 minor = iminor(file->f_path.dentry->d_inode);
448 rt = &rtlx->channel[minor];
450 /* any space left... */
451 if (!rtlx_write_poll(minor)) {
454 if (file->f_flags & O_NONBLOCK)
457 __wait_event_interruptible(channel_wqs[minor].rt_queue,
458 rtlx_write_poll(minor),
464 return rtlx_write(minor, buffer, count);
467 static const struct file_operations rtlx_fops = {
468 .owner = THIS_MODULE,
470 .release = file_release,
476 static struct irqaction rtlx_irq = {
477 .handler = rtlx_interrupt,
478 .flags = IRQF_DISABLED,
482 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
484 static char register_chrdev_failed[] __initdata =
485 KERN_ERR "rtlx_module_init: unable to register device\n";
487 static int __init rtlx_module_init(void)
492 if (!cpu_has_mipsmt) {
493 printk("VPE loader: not a MIPS MT capable processor\n");
498 printk(KERN_WARNING "No TCs reserved for AP/SP, not "
499 "initializing RTLX.\nPass maxtcs=<n> argument as kernel "
505 major = register_chrdev(0, module_name, &rtlx_fops);
507 printk(register_chrdev_failed);
511 /* initialise the wait queues */
512 for (i = 0; i < RTLX_CHANNELS; i++) {
513 init_waitqueue_head(&channel_wqs[i].rt_queue);
514 init_waitqueue_head(&channel_wqs[i].lx_queue);
515 atomic_set(&channel_wqs[i].in_open, 0);
516 mutex_init(&channel_wqs[i].mutex);
518 dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
519 "%s%d", module_name, i);
526 /* set up notifiers */
527 notify.start = starting;
528 notify.stop = stopping;
529 vpe_notify(tclimit, ¬ify);
532 set_vi_handler(MIPS_CPU_RTLX_IRQ, rtlx_dispatch);
534 pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
539 rtlx_irq.dev_id = rtlx;
540 setup_irq(rtlx_irq_num, &rtlx_irq);
545 for (i = 0; i < RTLX_CHANNELS; i++)
546 device_destroy(mt_class, MKDEV(major, i));
551 static void __exit rtlx_module_exit(void)
555 for (i = 0; i < RTLX_CHANNELS; i++)
556 device_destroy(mt_class, MKDEV(major, i));
558 unregister_chrdev(major, module_name);
561 module_init(rtlx_module_init);
562 module_exit(rtlx_module_exit);
564 MODULE_DESCRIPTION("MIPS RTLX");
565 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
566 MODULE_LICENSE("GPL");