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/syscalls.h>
32 #include <linux/moduleloader.h>
33 #include <linux/interrupt.h>
34 #include <linux/poll.h>
35 #include <linux/sched.h>
36 #include <linux/wait.h>
37 #include <asm/mipsmtregs.h>
38 #include <asm/mips_mt.h>
39 #include <asm/cacheflush.h>
40 #include <asm/atomic.h>
42 #include <asm/processor.h>
43 #include <asm/mips_mt.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
= 0;
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
)
77 for (i
= 0; i
< RTLX_CHANNELS
; i
++) {
78 wake_up(&channel_wqs
[i
].lx_queue
);
79 wake_up(&channel_wqs
[i
].rt_queue
);
85 static void __used
dump_rtlx(void)
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
);
108 /* call when we have the address of the shared structure from the SP side. */
109 static int rtlx_init(struct rtlx_info
*rtlxi
)
111 if (rtlxi
->id
!= RTLX_ID
) {
112 printk(KERN_ERR
"no valid RTLX id at 0x%p 0x%lx\n", rtlxi
, rtlxi
->id
);
122 static void starting(int vpe
)
127 /* force a reload of rtlx */
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
);
135 static void stopping(int vpe
)
140 for (i
= 0; i
< RTLX_CHANNELS
; i
++)
141 wake_up_interruptible(&channel_wqs
[i
].lx_queue
);
145 int rtlx_open(int index
, int can_sleep
)
147 struct rtlx_info
**p
;
148 struct rtlx_channel
*chan
;
149 enum rtlx_state state
;
152 if (index
>= RTLX_CHANNELS
) {
153 printk(KERN_DEBUG
"rtlx_open index out of range\n");
157 if (atomic_inc_return(&channel_wqs
[index
].in_open
) > 1) {
158 printk(KERN_DEBUG
"rtlx_open channel %d already opened\n",
165 if( (p
= vpe_get_shared(tclimit
)) == NULL
) {
167 __wait_event_interruptible(channel_wqs
[index
].lx_queue
,
168 (p
= vpe_get_shared(tclimit
)),
173 printk(KERN_DEBUG
"No SP program loaded, and device "
174 "opened with O_NONBLOCK\n");
186 prepare_to_wait(&channel_wqs
[index
].lx_queue
, &wait
, TASK_INTERRUPTIBLE
);
190 if (!signal_pending(current
)) {
197 finish_wait(&channel_wqs
[index
].lx_queue
, &wait
);
199 printk(" *vpe_get_shared is NULL. "
200 "Has an SP program been loaded?\n");
206 if ((unsigned int)*p
< KSEG0
) {
207 printk(KERN_WARNING
"vpe_get_shared returned an invalid pointer "
208 "maybe an error code %d\n", (int)*p
);
213 if ((ret
= rtlx_init(*p
)) < 0)
217 chan
= &rtlx
->channel
[index
];
219 state
= xchg(&chan
->lx_state
, RTLX_STATE_OPENED
);
220 if (state
== RTLX_STATE_OPENED
) {
227 atomic_dec(&channel_wqs
[index
].in_open
);
234 int rtlx_release(int index
)
236 rtlx
->channel
[index
].lx_state
= RTLX_STATE_UNUSED
;
240 unsigned int rtlx_read_poll(int index
, int can_sleep
)
242 struct rtlx_channel
*chan
;
247 chan
= &rtlx
->channel
[index
];
249 /* data available to read? */
250 if (chan
->lx_read
== chan
->lx_write
) {
254 __wait_event_interruptible(channel_wqs
[index
].lx_queue
,
255 chan
->lx_read
!= chan
->lx_write
|| sp_stopping
,
266 return (chan
->lx_write
+ chan
->buffer_size
- chan
->lx_read
)
270 static inline int write_spacefree(int read
, int write
, int size
)
274 * Never fill the buffer completely, so indexes are always
275 * equal if empty and only empty, or !equal if data available
280 return ((read
+ size
- write
) % size
) - 1;
283 unsigned int rtlx_write_poll(int index
)
285 struct rtlx_channel
*chan
= &rtlx
->channel
[index
];
286 return write_spacefree(chan
->rt_read
, chan
->rt_write
, chan
->buffer_size
);
289 ssize_t
rtlx_read(int index
, void __user
*buff
, size_t count
)
291 size_t lx_write
, fl
= 0L;
292 struct rtlx_channel
*lx
;
293 unsigned long failed
;
298 lx
= &rtlx
->channel
[index
];
300 mutex_lock(&channel_wqs
[index
].mutex
);
302 lx_write
= lx
->lx_write
;
304 /* find out how much in total */
306 (size_t)(lx_write
+ lx
->buffer_size
- lx
->lx_read
)
309 /* then how much from the read pointer onwards */
310 fl
= min(count
, (size_t)lx
->buffer_size
- lx
->lx_read
);
312 failed
= copy_to_user(buff
, lx
->lx_buffer
+ lx
->lx_read
, fl
);
316 /* and if there is anything left at the beginning of the buffer */
318 failed
= copy_to_user(buff
+ fl
, lx
->lx_buffer
, count
- fl
);
324 lx
->lx_read
= (lx
->lx_read
+ count
) % lx
->buffer_size
;
326 mutex_unlock(&channel_wqs
[index
].mutex
);
331 ssize_t
rtlx_write(int index
, const void __user
*buffer
, size_t count
)
333 struct rtlx_channel
*rt
;
334 unsigned long failed
;
341 rt
= &rtlx
->channel
[index
];
343 mutex_lock(&channel_wqs
[index
].mutex
);
345 rt_read
= rt
->rt_read
;
347 /* total number of bytes to copy */
349 (size_t)write_spacefree(rt_read
, rt
->rt_write
, rt
->buffer_size
));
351 /* first bit from write pointer to the end of the buffer, or count */
352 fl
= min(count
, (size_t) rt
->buffer_size
- rt
->rt_write
);
354 failed
= copy_from_user(rt
->rt_buffer
+ rt
->rt_write
, buffer
, fl
);
358 /* if there's any left copy to the beginning of the buffer */
360 failed
= copy_from_user(rt
->rt_buffer
, buffer
+ fl
, count
- fl
);
367 rt
->rt_write
= (rt
->rt_write
+ count
) % rt
->buffer_size
;
369 mutex_unlock(&channel_wqs
[index
].mutex
);
375 static int file_open(struct inode
*inode
, struct file
*filp
)
377 int minor
= iminor(inode
);
379 return rtlx_open(minor
, (filp
->f_flags
& O_NONBLOCK
) ? 0 : 1);
382 static int file_release(struct inode
*inode
, struct file
*filp
)
384 int minor
= iminor(inode
);
386 return rtlx_release(minor
);
389 static unsigned int file_poll(struct file
*file
, poll_table
* wait
)
392 unsigned int mask
= 0;
394 minor
= iminor(file
->f_path
.dentry
->d_inode
);
396 poll_wait(file
, &channel_wqs
[minor
].rt_queue
, wait
);
397 poll_wait(file
, &channel_wqs
[minor
].lx_queue
, wait
);
402 /* data available to read? */
403 if (rtlx_read_poll(minor
, 0))
404 mask
|= POLLIN
| POLLRDNORM
;
407 if (rtlx_write_poll(minor
))
408 mask
|= POLLOUT
| POLLWRNORM
;
413 static ssize_t
file_read(struct file
*file
, char __user
* buffer
, size_t count
,
416 int minor
= iminor(file
->f_path
.dentry
->d_inode
);
418 /* data available? */
419 if (!rtlx_read_poll(minor
, (file
->f_flags
& O_NONBLOCK
) ? 0 : 1)) {
420 return 0; // -EAGAIN makes cat whinge
423 return rtlx_read(minor
, buffer
, count
);
426 static ssize_t
file_write(struct file
*file
, const char __user
* buffer
,
427 size_t count
, loff_t
* ppos
)
430 struct rtlx_channel
*rt
;
432 minor
= iminor(file
->f_path
.dentry
->d_inode
);
433 rt
= &rtlx
->channel
[minor
];
435 /* any space left... */
436 if (!rtlx_write_poll(minor
)) {
439 if (file
->f_flags
& O_NONBLOCK
)
442 __wait_event_interruptible(channel_wqs
[minor
].rt_queue
,
443 rtlx_write_poll(minor
),
449 return rtlx_write(minor
, buffer
, count
);
452 static const struct file_operations rtlx_fops
= {
453 .owner
= THIS_MODULE
,
455 .release
= file_release
,
461 static struct irqaction rtlx_irq
= {
462 .handler
= rtlx_interrupt
,
463 .flags
= IRQF_DISABLED
,
467 static int rtlx_irq_num
= MIPS_CPU_IRQ_BASE
+ MIPS_CPU_RTLX_IRQ
;
469 static char register_chrdev_failed
[] __initdata
=
470 KERN_ERR
"rtlx_module_init: unable to register device\n";
472 static int __init
rtlx_module_init(void)
477 if (!cpu_has_mipsmt
) {
478 printk("VPE loader: not a MIPS MT capable processor\n");
483 printk(KERN_WARNING
"No TCs reserved for AP/SP, not "
484 "initializing RTLX.\nPass maxtcs=<n> argument as kernel "
490 major
= register_chrdev(0, module_name
, &rtlx_fops
);
492 printk(register_chrdev_failed
);
496 /* initialise the wait queues */
497 for (i
= 0; i
< RTLX_CHANNELS
; i
++) {
498 init_waitqueue_head(&channel_wqs
[i
].rt_queue
);
499 init_waitqueue_head(&channel_wqs
[i
].lx_queue
);
500 atomic_set(&channel_wqs
[i
].in_open
, 0);
501 mutex_init(&channel_wqs
[i
].mutex
);
503 dev
= device_create(mt_class
, NULL
, MKDEV(major
, i
),
504 "%s%d", module_name
, i
);
511 /* set up notifiers */
512 notify
.start
= starting
;
513 notify
.stop
= stopping
;
514 vpe_notify(tclimit
, ¬ify
);
517 set_vi_handler(MIPS_CPU_RTLX_IRQ
, rtlx_dispatch
);
519 rtlx_irq
.dev_id
= rtlx
;
520 setup_irq(rtlx_irq_num
, &rtlx_irq
);
525 for (i
= 0; i
< RTLX_CHANNELS
; i
++)
526 device_destroy(mt_class
, MKDEV(major
, i
));
531 static void __exit
rtlx_module_exit(void)
535 for (i
= 0; i
< RTLX_CHANNELS
; i
++)
536 device_destroy(mt_class
, MKDEV(major
, i
));
538 unregister_chrdev(major
, module_name
);
541 module_init(rtlx_module_init
);
542 module_exit(rtlx_module_exit
);
544 MODULE_DESCRIPTION("MIPS RTLX");
545 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
546 MODULE_LICENSE("GPL");