2 * An implementation of a loadable kernel mode driver providing
3 * multiple kernel/user space bidirectional communications links.
5 * Author: Alan Cox <alan@redhat.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
12 * Adapted to become the Linux 2.0 Coda pseudo device
13 * Peter Braam <braam@maths.ox.ac.uk>
14 * Michael Callahan <mjc@emmy.smith.edu>
16 * Changes for Linux 2.1
17 * Copyright (c) 1997 Carnegie-Mellon University
20 #include <linux/module.h>
21 #include <linux/errno.h>
22 #include <linux/kernel.h>
23 #include <linux/major.h>
24 #include <linux/time.h>
26 #include <linux/slab.h>
27 #include <linux/ioport.h>
28 #include <linux/fcntl.h>
29 #include <linux/delay.h>
30 #include <linux/skbuff.h>
31 #include <linux/proc_fs.h>
32 #include <linux/devfs_fs_kernel.h>
33 #include <linux/vmalloc.h>
35 #include <linux/file.h>
36 #include <linux/poll.h>
37 #include <linux/init.h>
38 #include <linux/list.h>
39 #include <linux/smp_lock.h>
40 #include <linux/device.h>
42 #include <asm/system.h>
44 #include <asm/uaccess.h>
46 #include <linux/coda.h>
47 #include <linux/coda_linux.h>
48 #include <linux/coda_fs_i.h>
49 #include <linux/coda_psdev.h>
50 #include <linux/coda_proc.h>
52 #define upc_free(r) kfree(r)
57 extern struct file_system_type coda_fs_type;
60 int coda_hard; /* allows signals during upcalls */
61 unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
64 struct venus_comm coda_comms[MAX_CODADEVS];
65 static struct class_simple *coda_psdev_class;
71 static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
73 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
74 unsigned int mask = POLLOUT | POLLWRNORM;
76 poll_wait(file, &vcp->vc_waitq, wait);
77 if (!list_empty(&vcp->vc_pending))
78 mask |= POLLIN | POLLRDNORM;
83 static int coda_psdev_ioctl(struct inode * inode, struct file * filp,
84 unsigned int cmd, unsigned long arg)
89 case CIOC_KERNEL_VERSION:
90 data = CODA_KERNEL_VERSION;
91 return put_user(data, (int *) arg);
100 * Receive a message written by Venus to the psdev
103 static ssize_t coda_psdev_write(struct file *file, const char *buf,
104 size_t nbytes, loff_t *off)
106 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
107 struct upc_req *req = NULL;
109 struct list_head *lh;
110 struct coda_in_hdr hdr;
111 ssize_t retval = 0, count = 0;
114 /* Peek at the opcode, uniquefier */
115 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
118 if (DOWNCALL(hdr.opcode)) {
119 struct super_block *sb = NULL;
120 union outputArgs *dcbuf;
121 int size = sizeof(*dcbuf);
129 if ( nbytes < sizeof(struct coda_out_hdr) ) {
130 printk("coda_downcall opc %d uniq %d, not enough!\n",
131 hdr.opcode, hdr.unique);
135 if ( nbytes > size ) {
136 printk("Coda: downcall opc %d, uniq %d, too much!",
137 hdr.opcode, hdr.unique);
140 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
141 if (copy_from_user(dcbuf, buf, nbytes)) {
142 CODA_FREE(dcbuf, nbytes);
147 /* what downcall errors does Venus handle ? */
149 error = coda_downcall(hdr.opcode, dcbuf, sb);
152 CODA_FREE(dcbuf, nbytes);
154 printk("psdev_write: coda_downcall error: %d\n", error);
162 /* Look for the message on the processing queue. */
164 list_for_each(lh, &vcp->vc_processing) {
165 tmp = list_entry(lh, struct upc_req , uc_chain);
166 if (tmp->uc_unique == hdr.unique) {
168 list_del(&req->uc_chain);
175 printk("psdev_write: msg (%d, %d) not found\n",
176 hdr.opcode, hdr.unique);
181 /* move data into response buffer. */
182 if (req->uc_outSize < nbytes) {
183 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
184 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
185 nbytes = req->uc_outSize; /* don't have more space! */
187 if (copy_from_user(req->uc_data, buf, nbytes)) {
188 req->uc_flags |= REQ_ABORT;
189 wake_up(&req->uc_sleep);
194 /* adjust outsize. is this useful ?? */
195 req->uc_outSize = nbytes;
196 req->uc_flags |= REQ_WRITE;
199 /* Convert filedescriptor into a file handle */
200 if (req->uc_opcode == CODA_OPEN_BY_FD) {
201 struct coda_open_by_fd_out *outp =
202 (struct coda_open_by_fd_out *)req->uc_data;
203 outp->fh = fget(outp->fd);
206 wake_up(&req->uc_sleep);
208 return(count ? count : retval);
212 * Read a message from the kernel to Venus
215 static ssize_t coda_psdev_read(struct file * file, char * buf,
216 size_t nbytes, loff_t *off)
218 DECLARE_WAITQUEUE(wait, current);
219 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
221 ssize_t retval = 0, count = 0;
228 add_wait_queue(&vcp->vc_waitq, &wait);
229 set_current_state(TASK_INTERRUPTIBLE);
231 while (list_empty(&vcp->vc_pending)) {
232 if (file->f_flags & O_NONBLOCK) {
236 if (signal_pending(current)) {
237 retval = -ERESTARTSYS;
243 set_current_state(TASK_RUNNING);
244 remove_wait_queue(&vcp->vc_waitq, &wait);
249 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
250 list_del(&req->uc_chain);
252 /* Move the input args into userspace */
253 count = req->uc_inSize;
254 if (nbytes < req->uc_inSize) {
255 printk ("psdev_read: Venus read %ld bytes of %d in message\n",
256 (long)nbytes, req->uc_inSize);
260 if (copy_to_user(buf, req->uc_data, count))
263 /* If request was not a signal, enqueue and don't free */
264 if (!(req->uc_flags & REQ_ASYNC)) {
265 req->uc_flags |= REQ_READ;
266 list_add(&(req->uc_chain), vcp->vc_processing.prev);
270 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
274 return (count ? count : retval);
277 static int coda_psdev_open(struct inode * inode, struct file * file)
279 struct venus_comm *vcp;
284 if(idx >= MAX_CODADEVS) {
289 vcp = &coda_comms[idx];
295 if (!vcp->vc_inuse++) {
296 INIT_LIST_HEAD(&vcp->vc_pending);
297 INIT_LIST_HEAD(&vcp->vc_processing);
298 init_waitqueue_head(&vcp->vc_waitq);
303 file->private_data = vcp;
310 static int coda_psdev_release(struct inode * inode, struct file * file)
312 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
314 struct list_head *lh, *next;
317 if ( !vcp->vc_inuse ) {
319 printk("psdev_release: Not open.\n");
323 if (--vcp->vc_inuse) {
328 /* Wakeup clients so they can return. */
329 list_for_each_safe(lh, next, &vcp->vc_pending) {
330 req = list_entry(lh, struct upc_req, uc_chain);
331 /* Async requests need to be freed here */
332 if (req->uc_flags & REQ_ASYNC) {
333 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
337 req->uc_flags |= REQ_ABORT;
338 wake_up(&req->uc_sleep);
341 list_for_each_entry(req, &vcp->vc_processing, uc_chain) {
342 req->uc_flags |= REQ_ABORT;
343 wake_up(&req->uc_sleep);
351 static struct file_operations coda_psdev_fops = {
352 .owner = THIS_MODULE,
353 .read = coda_psdev_read,
354 .write = coda_psdev_write,
355 .poll = coda_psdev_poll,
356 .ioctl = coda_psdev_ioctl,
357 .open = coda_psdev_open,
358 .release = coda_psdev_release,
361 static int init_coda_psdev(void)
364 if (register_chrdev(CODA_PSDEV_MAJOR,"coda_psdev",
366 printk(KERN_ERR "coda_psdev: unable to get major %d\n",
370 coda_psdev_class = class_simple_create(THIS_MODULE, "coda_psdev");
371 if (IS_ERR(coda_psdev_class)) {
372 err = PTR_ERR(coda_psdev_class);
375 devfs_mk_dir ("coda");
376 for (i = 0; i < MAX_CODADEVS; i++) {
377 class_simple_device_add(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR,i),
379 err = devfs_mk_cdev(MKDEV(CODA_PSDEV_MAJOR, i),
380 S_IFCHR|S_IRUSR|S_IWUSR, "coda/%d", i);
388 for (i = 0; i < MAX_CODADEVS; i++)
389 class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i));
390 class_simple_destroy(coda_psdev_class);
392 unregister_chrdev(CODA_PSDEV_MAJOR, "coda_psdev");
398 MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>");
399 MODULE_LICENSE("GPL");
401 extern int coda_init_inodecache(void);
402 extern void coda_destroy_inodecache(void);
403 static int __init init_coda(void)
407 printk(KERN_INFO "Coda Kernel/Venus communications, "
408 #ifdef CODA_FS_OLD_API
413 ", coda@cs.cmu.edu\n");
415 status = coda_init_inodecache();
418 status = init_coda_psdev();
420 printk("Problem (%d) in init_coda_psdev\n", status);
424 status = register_filesystem(&coda_fs_type);
426 printk("coda: failed to register filesystem!\n");
431 for (i = 0; i < MAX_CODADEVS; i++) {
432 class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i));
433 devfs_remove("coda/%d", i);
435 class_simple_destroy(coda_psdev_class);
436 devfs_remove("coda");
437 unregister_chrdev(CODA_PSDEV_MAJOR,"coda_psdev");
440 coda_destroy_inodecache();
445 static void __exit exit_coda(void)
449 err = unregister_filesystem(&coda_fs_type);
451 printk("coda: failed to unregister filesystem\n");
453 for (i = 0; i < MAX_CODADEVS; i++) {
454 class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i));
455 devfs_remove("coda/%d", i);
457 class_simple_destroy(coda_psdev_class);
458 devfs_remove("coda");
459 unregister_chrdev(CODA_PSDEV_MAJOR, "coda_psdev");
461 coda_destroy_inodecache();
464 module_init(init_coda);
465 module_exit(exit_coda);