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dda44eb2 HM |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * VAS user space API for its accelerators (Only NX-GZIP is supported now) | |
4 | * Copyright (C) 2019 Haren Myneni, IBM Corp | |
5 | */ | |
6 | ||
7 | #include <linux/kernel.h> | |
8 | #include <linux/device.h> | |
9 | #include <linux/cdev.h> | |
10 | #include <linux/fs.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/uaccess.h> | |
3b267973 HM |
13 | #include <linux/kthread.h> |
14 | #include <linux/sched/signal.h> | |
15 | #include <linux/mmu_context.h> | |
413d6ed3 | 16 | #include <linux/io.h> |
dda44eb2 HM |
17 | #include <asm/vas.h> |
18 | #include <uapi/asm/vas-api.h> | |
dda44eb2 HM |
19 | |
20 | /* | |
21 | * The driver creates the device node that can be used as follows: | |
22 | * For NX-GZIP | |
23 | * | |
24 | * fd = open("/dev/crypto/nx-gzip", O_RDWR); | |
25 | * rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr); | |
26 | * paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL). | |
27 | * vas_copy(&crb, 0, 1); | |
28 | * vas_paste(paste_addr, 0, 1); | |
29 | * close(fd) or exit process to close window. | |
30 | * | |
31 | * where "vas_copy" and "vas_paste" are defined in copy-paste.h. | |
32 | * copy/paste returns to the user space directly. So refer NX hardware | |
1fd02f66 | 33 | * documentation for exact copy/paste usage and completion / error |
dda44eb2 HM |
34 | * conditions. |
35 | */ | |
36 | ||
37 | /* | |
38 | * Wrapper object for the nx-gzip device - there is just one instance of | |
39 | * this node for the whole system. | |
40 | */ | |
41 | static struct coproc_dev { | |
42 | struct cdev cdev; | |
43 | struct device *device; | |
44 | char *name; | |
45 | dev_t devt; | |
46 | struct class *class; | |
47 | enum vas_cop_type cop_type; | |
1a0d0d5e | 48 | const struct vas_user_win_ops *vops; |
dda44eb2 HM |
49 | } coproc_device; |
50 | ||
51 | struct coproc_instance { | |
52 | struct coproc_dev *coproc; | |
53 | struct vas_window *txwin; | |
54 | }; | |
55 | ||
fb12940f | 56 | static char *coproc_devnode(const struct device *dev, umode_t *mode) |
dda44eb2 HM |
57 | { |
58 | return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev)); | |
59 | } | |
60 | ||
3856aa54 HM |
61 | /* |
62 | * Take reference to pid and mm | |
63 | */ | |
64 | int get_vas_user_win_ref(struct vas_user_win_ref *task_ref) | |
65 | { | |
66 | /* | |
67 | * Window opened by a child thread may not be closed when | |
68 | * it exits. So take reference to its pid and release it | |
69 | * when the window is free by parent thread. | |
70 | * Acquire a reference to the task's pid to make sure | |
71 | * pid will not be re-used - needed only for multithread | |
72 | * applications. | |
73 | */ | |
74 | task_ref->pid = get_task_pid(current, PIDTYPE_PID); | |
75 | /* | |
76 | * Acquire a reference to the task's mm. | |
77 | */ | |
78 | task_ref->mm = get_task_mm(current); | |
79 | if (!task_ref->mm) { | |
80 | put_pid(task_ref->pid); | |
81 | pr_err("VAS: pid(%d): mm_struct is not found\n", | |
82 | current->pid); | |
83 | return -EPERM; | |
84 | } | |
85 | ||
86 | mmgrab(task_ref->mm); | |
87 | mmput(task_ref->mm); | |
88 | /* | |
89 | * Process closes window during exit. In the case of | |
90 | * multithread application, the child thread can open | |
91 | * window and can exit without closing it. So takes tgid | |
92 | * reference until window closed to make sure tgid is not | |
93 | * reused. | |
94 | */ | |
95 | task_ref->tgid = find_get_pid(task_tgid_vnr(current)); | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
3b267973 HM |
100 | /* |
101 | * Successful return must release the task reference with | |
102 | * put_task_struct | |
103 | */ | |
104 | static bool ref_get_pid_and_task(struct vas_user_win_ref *task_ref, | |
105 | struct task_struct **tskp, struct pid **pidp) | |
106 | { | |
107 | struct task_struct *tsk; | |
108 | struct pid *pid; | |
109 | ||
110 | pid = task_ref->pid; | |
111 | tsk = get_pid_task(pid, PIDTYPE_PID); | |
112 | if (!tsk) { | |
113 | pid = task_ref->tgid; | |
114 | tsk = get_pid_task(pid, PIDTYPE_PID); | |
115 | /* | |
116 | * Parent thread (tgid) will be closing window when it | |
117 | * exits. So should not get here. | |
118 | */ | |
119 | if (WARN_ON_ONCE(!tsk)) | |
120 | return false; | |
121 | } | |
122 | ||
123 | /* Return if the task is exiting. */ | |
124 | if (tsk->flags & PF_EXITING) { | |
125 | put_task_struct(tsk); | |
126 | return false; | |
127 | } | |
128 | ||
129 | *tskp = tsk; | |
130 | *pidp = pid; | |
131 | ||
132 | return true; | |
133 | } | |
134 | ||
135 | /* | |
136 | * Update the CSB to indicate a translation error. | |
137 | * | |
138 | * User space will be polling on CSB after the request is issued. | |
139 | * If NX can handle the request without any issues, it updates CSB. | |
140 | * Whereas if NX encounters page fault, the kernel will handle the | |
141 | * fault and update CSB with translation error. | |
142 | * | |
143 | * If we are unable to update the CSB means copy_to_user failed due to | |
144 | * invalid csb_addr, send a signal to the process. | |
145 | */ | |
146 | void vas_update_csb(struct coprocessor_request_block *crb, | |
147 | struct vas_user_win_ref *task_ref) | |
148 | { | |
149 | struct coprocessor_status_block csb; | |
150 | struct kernel_siginfo info; | |
151 | struct task_struct *tsk; | |
152 | void __user *csb_addr; | |
153 | struct pid *pid; | |
154 | int rc; | |
155 | ||
156 | /* | |
157 | * NX user space windows can not be opened for task->mm=NULL | |
158 | * and faults will not be generated for kernel requests. | |
159 | */ | |
160 | if (WARN_ON_ONCE(!task_ref->mm)) | |
161 | return; | |
162 | ||
163 | csb_addr = (void __user *)be64_to_cpu(crb->csb_addr); | |
164 | ||
165 | memset(&csb, 0, sizeof(csb)); | |
166 | csb.cc = CSB_CC_FAULT_ADDRESS; | |
167 | csb.ce = CSB_CE_TERMINATION; | |
168 | csb.cs = 0; | |
169 | csb.count = 0; | |
170 | ||
171 | /* | |
172 | * NX operates and returns in BE format as defined CRB struct. | |
173 | * So saves fault_storage_addr in BE as NX pastes in FIFO and | |
174 | * expects user space to convert to CPU format. | |
175 | */ | |
176 | csb.address = crb->stamp.nx.fault_storage_addr; | |
177 | csb.flags = 0; | |
178 | ||
179 | /* | |
180 | * Process closes send window after all pending NX requests are | |
181 | * completed. In multi-thread applications, a child thread can | |
182 | * open a window and can exit without closing it. May be some | |
183 | * requests are pending or this window can be used by other | |
184 | * threads later. We should handle faults if NX encounters | |
185 | * pages faults on these requests. Update CSB with translation | |
186 | * error and fault address. If csb_addr passed by user space is | |
187 | * invalid, send SEGV signal to pid saved in window. If the | |
188 | * child thread is not running, send the signal to tgid. | |
189 | * Parent thread (tgid) will close this window upon its exit. | |
190 | * | |
191 | * pid and mm references are taken when window is opened by | |
192 | * process (pid). So tgid is used only when child thread opens | |
193 | * a window and exits without closing it. | |
194 | */ | |
195 | ||
196 | if (!ref_get_pid_and_task(task_ref, &tsk, &pid)) | |
197 | return; | |
198 | ||
199 | kthread_use_mm(task_ref->mm); | |
200 | rc = copy_to_user(csb_addr, &csb, sizeof(csb)); | |
201 | /* | |
202 | * User space polls on csb.flags (first byte). So add barrier | |
203 | * then copy first byte with csb flags update. | |
204 | */ | |
205 | if (!rc) { | |
206 | csb.flags = CSB_V; | |
207 | /* Make sure update to csb.flags is visible now */ | |
208 | smp_mb(); | |
209 | rc = copy_to_user(csb_addr, &csb, sizeof(u8)); | |
210 | } | |
211 | kthread_unuse_mm(task_ref->mm); | |
212 | put_task_struct(tsk); | |
213 | ||
214 | /* Success */ | |
215 | if (!rc) | |
216 | return; | |
217 | ||
218 | ||
219 | pr_debug("Invalid CSB address 0x%p signalling pid(%d)\n", | |
220 | csb_addr, pid_vnr(pid)); | |
221 | ||
222 | clear_siginfo(&info); | |
223 | info.si_signo = SIGSEGV; | |
224 | info.si_errno = EFAULT; | |
225 | info.si_code = SEGV_MAPERR; | |
226 | info.si_addr = csb_addr; | |
227 | /* | |
228 | * process will be polling on csb.flags after request is sent to | |
229 | * NX. So generally CSB update should not fail except when an | |
230 | * application passes invalid csb_addr. So an error message will | |
231 | * be displayed and leave it to user space whether to ignore or | |
232 | * handle this signal. | |
233 | */ | |
234 | rcu_read_lock(); | |
235 | rc = kill_pid_info(SIGSEGV, &info, pid); | |
236 | rcu_read_unlock(); | |
237 | ||
238 | pr_devel("%s(): pid %d kill_proc_info() rc %d\n", __func__, | |
239 | pid_vnr(pid), rc); | |
240 | } | |
241 | ||
242 | void vas_dump_crb(struct coprocessor_request_block *crb) | |
243 | { | |
244 | struct data_descriptor_entry *dde; | |
245 | struct nx_fault_stamp *nx; | |
246 | ||
247 | dde = &crb->source; | |
248 | pr_devel("SrcDDE: addr 0x%llx, len %d, count %d, idx %d, flags %d\n", | |
249 | be64_to_cpu(dde->address), be32_to_cpu(dde->length), | |
250 | dde->count, dde->index, dde->flags); | |
251 | ||
252 | dde = &crb->target; | |
253 | pr_devel("TgtDDE: addr 0x%llx, len %d, count %d, idx %d, flags %d\n", | |
254 | be64_to_cpu(dde->address), be32_to_cpu(dde->length), | |
255 | dde->count, dde->index, dde->flags); | |
256 | ||
257 | nx = &crb->stamp.nx; | |
258 | pr_devel("NX Stamp: PSWID 0x%x, FSA 0x%llx, flags 0x%x, FS 0x%x\n", | |
259 | be32_to_cpu(nx->pswid), | |
260 | be64_to_cpu(crb->stamp.nx.fault_storage_addr), | |
261 | nx->flags, nx->fault_status); | |
262 | } | |
263 | ||
dda44eb2 HM |
264 | static int coproc_open(struct inode *inode, struct file *fp) |
265 | { | |
266 | struct coproc_instance *cp_inst; | |
267 | ||
268 | cp_inst = kzalloc(sizeof(*cp_inst), GFP_KERNEL); | |
269 | if (!cp_inst) | |
270 | return -ENOMEM; | |
271 | ||
272 | cp_inst->coproc = container_of(inode->i_cdev, struct coproc_dev, | |
273 | cdev); | |
274 | fp->private_data = cp_inst; | |
275 | ||
276 | return 0; | |
277 | } | |
278 | ||
279 | static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg) | |
280 | { | |
281 | void __user *uptr = (void __user *)arg; | |
dda44eb2 HM |
282 | struct vas_tx_win_open_attr uattr; |
283 | struct coproc_instance *cp_inst; | |
284 | struct vas_window *txwin; | |
1a0d0d5e | 285 | int rc; |
dda44eb2 HM |
286 | |
287 | cp_inst = fp->private_data; | |
288 | ||
289 | /* | |
290 | * One window for file descriptor | |
291 | */ | |
292 | if (cp_inst->txwin) | |
293 | return -EEXIST; | |
294 | ||
295 | rc = copy_from_user(&uattr, uptr, sizeof(uattr)); | |
296 | if (rc) { | |
297 | pr_err("%s(): copy_from_user() returns %d\n", __func__, rc); | |
298 | return -EFAULT; | |
299 | } | |
300 | ||
301 | if (uattr.version != 1) { | |
1a0d0d5e | 302 | pr_err("Invalid window open API version\n"); |
dda44eb2 HM |
303 | return -EINVAL; |
304 | } | |
305 | ||
61cb9ac6 | 306 | if (!cp_inst->coproc->vops || !cp_inst->coproc->vops->open_win) { |
1a0d0d5e HM |
307 | pr_err("VAS API is not registered\n"); |
308 | return -EACCES; | |
309 | } | |
dda44eb2 | 310 | |
1a0d0d5e HM |
311 | txwin = cp_inst->coproc->vops->open_win(uattr.vas_id, uattr.flags, |
312 | cp_inst->coproc->cop_type); | |
dda44eb2 | 313 | if (IS_ERR(txwin)) { |
1a0d0d5e HM |
314 | pr_err("%s() VAS window open failed, %ld\n", __func__, |
315 | PTR_ERR(txwin)); | |
dda44eb2 HM |
316 | return PTR_ERR(txwin); |
317 | } | |
318 | ||
1fe3a33b | 319 | mutex_init(&txwin->task_ref.mmap_mutex); |
dda44eb2 HM |
320 | cp_inst->txwin = txwin; |
321 | ||
322 | return 0; | |
323 | } | |
324 | ||
325 | static int coproc_release(struct inode *inode, struct file *fp) | |
326 | { | |
327 | struct coproc_instance *cp_inst = fp->private_data; | |
1a0d0d5e | 328 | int rc; |
dda44eb2 HM |
329 | |
330 | if (cp_inst->txwin) { | |
1a0d0d5e HM |
331 | if (cp_inst->coproc->vops && |
332 | cp_inst->coproc->vops->close_win) { | |
333 | rc = cp_inst->coproc->vops->close_win(cp_inst->txwin); | |
334 | if (rc) | |
335 | return rc; | |
336 | } | |
dda44eb2 HM |
337 | cp_inst->txwin = NULL; |
338 | } | |
339 | ||
340 | kfree(cp_inst); | |
341 | fp->private_data = NULL; | |
342 | ||
343 | /* | |
344 | * We don't know here if user has other receive windows | |
345 | * open, so we can't really call clear_thread_tidr(). | |
346 | * So, once the process calls set_thread_tidr(), the | |
347 | * TIDR value sticks around until process exits, resulting | |
348 | * in an extra copy in restore_sprs(). | |
349 | */ | |
350 | ||
351 | return 0; | |
352 | } | |
353 | ||
b5c63d90 HM |
354 | /* |
355 | * If the executed instruction that caused the fault was a paste, then | |
356 | * clear regs CR0[EQ], advance NIP, and return 0. Else return error code. | |
357 | */ | |
358 | static int do_fail_paste(void) | |
359 | { | |
360 | struct pt_regs *regs = current->thread.regs; | |
361 | u32 instword; | |
362 | ||
363 | if (WARN_ON_ONCE(!regs)) | |
364 | return -EINVAL; | |
365 | ||
366 | if (WARN_ON_ONCE(!user_mode(regs))) | |
367 | return -EINVAL; | |
368 | ||
369 | /* | |
370 | * If we couldn't translate the instruction, the driver should | |
371 | * return success without handling the fault, it will be retried | |
372 | * or the instruction fetch will fault. | |
373 | */ | |
374 | if (get_user(instword, (u32 __user *)(regs->nip))) | |
375 | return -EAGAIN; | |
376 | ||
377 | /* | |
378 | * Not a paste instruction, driver may fail the fault. | |
379 | */ | |
380 | if ((instword & PPC_INST_PASTE_MASK) != PPC_INST_PASTE) | |
381 | return -ENOENT; | |
382 | ||
383 | regs->ccr &= ~0xe0000000; /* Clear CR0[0-2] to fail paste */ | |
384 | regs_add_return_ip(regs, 4); /* Emulate the paste */ | |
385 | ||
386 | return 0; | |
387 | } | |
388 | ||
1fe3a33b HM |
389 | /* |
390 | * This fault handler is invoked when the core generates page fault on | |
391 | * the paste address. Happens if the kernel closes window in hypervisor | |
392 | * (on pseries) due to lost credit or the paste address is not mapped. | |
393 | */ | |
394 | static vm_fault_t vas_mmap_fault(struct vm_fault *vmf) | |
395 | { | |
396 | struct vm_area_struct *vma = vmf->vma; | |
397 | struct file *fp = vma->vm_file; | |
398 | struct coproc_instance *cp_inst = fp->private_data; | |
399 | struct vas_window *txwin; | |
400 | vm_fault_t fault; | |
401 | u64 paste_addr; | |
b5c63d90 | 402 | int ret; |
1fe3a33b HM |
403 | |
404 | /* | |
405 | * window is not opened. Shouldn't expect this error. | |
406 | */ | |
407 | if (!cp_inst || !cp_inst->txwin) { | |
408 | pr_err("%s(): Unexpected fault on paste address with TX window closed\n", | |
409 | __func__); | |
410 | return VM_FAULT_SIGBUS; | |
411 | } | |
412 | ||
413 | txwin = cp_inst->txwin; | |
414 | /* | |
415 | * When the LPAR lost credits due to core removal or during | |
416 | * migration, invalidate the existing mapping for the current | |
e9adcfec | 417 | * paste addresses and set windows in-active (zap_vma_pages in |
1fe3a33b HM |
418 | * reconfig_close_windows()). |
419 | * New mapping will be done later after migration or new credits | |
420 | * available. So continue to receive faults if the user space | |
421 | * issue NX request. | |
422 | */ | |
423 | if (txwin->task_ref.vma != vmf->vma) { | |
424 | pr_err("%s(): No previous mapping with paste address\n", | |
425 | __func__); | |
426 | return VM_FAULT_SIGBUS; | |
427 | } | |
428 | ||
429 | mutex_lock(&txwin->task_ref.mmap_mutex); | |
430 | /* | |
431 | * The window may be inactive due to lost credit (Ex: core | |
432 | * removal with DLPAR). If the window is active again when | |
433 | * the credit is available, map the new paste address at the | |
0d4bb5e4 | 434 | * window virtual address. |
1fe3a33b HM |
435 | */ |
436 | if (txwin->status == VAS_WIN_ACTIVE) { | |
437 | paste_addr = cp_inst->coproc->vops->paste_addr(txwin); | |
438 | if (paste_addr) { | |
439 | fault = vmf_insert_pfn(vma, vma->vm_start, | |
440 | (paste_addr >> PAGE_SHIFT)); | |
441 | mutex_unlock(&txwin->task_ref.mmap_mutex); | |
442 | return fault; | |
443 | } | |
444 | } | |
445 | mutex_unlock(&txwin->task_ref.mmap_mutex); | |
446 | ||
b5c63d90 HM |
447 | /* |
448 | * Received this fault due to closing the actual window. | |
449 | * It can happen during migration or lost credits. | |
450 | * Since no mapping, return the paste instruction failure | |
451 | * to the user space. | |
452 | */ | |
453 | ret = do_fail_paste(); | |
454 | /* | |
455 | * The user space can retry several times until success (needed | |
456 | * for migration) or should fallback to SW compression or | |
457 | * manage with the existing open windows if available. | |
458 | * Looking at sysfs interface, it can determine whether these | |
459 | * failures are coming during migration or core removal: | |
460 | * nr_used_credits > nr_total_credits when lost credits | |
461 | */ | |
462 | if (!ret || (ret == -EAGAIN)) | |
463 | return VM_FAULT_NOPAGE; | |
464 | ||
1fe3a33b HM |
465 | return VM_FAULT_SIGBUS; |
466 | } | |
467 | ||
468 | static const struct vm_operations_struct vas_vm_ops = { | |
469 | .fault = vas_mmap_fault, | |
470 | }; | |
471 | ||
dda44eb2 HM |
472 | static int coproc_mmap(struct file *fp, struct vm_area_struct *vma) |
473 | { | |
474 | struct coproc_instance *cp_inst = fp->private_data; | |
475 | struct vas_window *txwin; | |
476 | unsigned long pfn; | |
477 | u64 paste_addr; | |
478 | pgprot_t prot; | |
479 | int rc; | |
480 | ||
481 | txwin = cp_inst->txwin; | |
482 | ||
483 | if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) { | |
484 | pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__, | |
485 | (vma->vm_end - vma->vm_start), PAGE_SIZE); | |
486 | return -EINVAL; | |
487 | } | |
488 | ||
489 | /* Ensure instance has an open send window */ | |
490 | if (!txwin) { | |
491 | pr_err("%s(): No send window open?\n", __func__); | |
492 | return -EINVAL; | |
493 | } | |
494 | ||
61cb9ac6 | 495 | if (!cp_inst->coproc->vops || !cp_inst->coproc->vops->paste_addr) { |
1a0d0d5e HM |
496 | pr_err("%s(): VAS API is not registered\n", __func__); |
497 | return -EACCES; | |
498 | } | |
499 | ||
6a8d4ca8 HM |
500 | /* |
501 | * The initial mmap is done after the window is opened | |
502 | * with ioctl. But before mmap(), this window can be closed in | |
503 | * the hypervisor due to lost credit (core removal on pseries). | |
504 | * So if the window is not active, return mmap() failure with | |
505 | * -EACCES and expects the user space reissue mmap() when it | |
506 | * is active again or open new window when the credit is available. | |
507 | * mmap_mutex protects the paste address mmap() with DLPAR | |
508 | * close/open event and allows mmap() only when the window is | |
509 | * active. | |
510 | */ | |
511 | mutex_lock(&txwin->task_ref.mmap_mutex); | |
512 | if (txwin->status != VAS_WIN_ACTIVE) { | |
513 | pr_err("%s(): Window is not active\n", __func__); | |
514 | rc = -EACCES; | |
515 | goto out; | |
516 | } | |
517 | ||
1a0d0d5e HM |
518 | paste_addr = cp_inst->coproc->vops->paste_addr(txwin); |
519 | if (!paste_addr) { | |
520 | pr_err("%s(): Window paste address failed\n", __func__); | |
6a8d4ca8 HM |
521 | rc = -EINVAL; |
522 | goto out; | |
1a0d0d5e HM |
523 | } |
524 | ||
dda44eb2 HM |
525 | pfn = paste_addr >> PAGE_SHIFT; |
526 | ||
527 | /* flags, page_prot from cxl_mmap(), except we want cachable */ | |
1c71222e | 528 | vm_flags_set(vma, VM_IO | VM_PFNMAP); |
dda44eb2 HM |
529 | vma->vm_page_prot = pgprot_cached(vma->vm_page_prot); |
530 | ||
531 | prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY); | |
532 | ||
533 | rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff, | |
534 | vma->vm_end - vma->vm_start, prot); | |
535 | ||
536 | pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__, | |
537 | paste_addr, vma->vm_start, rc); | |
538 | ||
1fe3a33b HM |
539 | txwin->task_ref.vma = vma; |
540 | vma->vm_ops = &vas_vm_ops; | |
541 | ||
6a8d4ca8 HM |
542 | out: |
543 | mutex_unlock(&txwin->task_ref.mmap_mutex); | |
dda44eb2 HM |
544 | return rc; |
545 | } | |
546 | ||
547 | static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) | |
548 | { | |
549 | switch (cmd) { | |
550 | case VAS_TX_WIN_OPEN: | |
551 | return coproc_ioc_tx_win_open(fp, arg); | |
552 | default: | |
553 | return -EINVAL; | |
554 | } | |
555 | } | |
556 | ||
557 | static struct file_operations coproc_fops = { | |
558 | .open = coproc_open, | |
559 | .release = coproc_release, | |
560 | .mmap = coproc_mmap, | |
561 | .unlocked_ioctl = coproc_ioctl, | |
562 | }; | |
563 | ||
564 | /* | |
565 | * Supporting only nx-gzip coprocessor type now, but this API code | |
566 | * extended to other coprocessor types later. | |
567 | */ | |
568 | int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type, | |
1a0d0d5e HM |
569 | const char *name, |
570 | const struct vas_user_win_ops *vops) | |
dda44eb2 HM |
571 | { |
572 | int rc = -EINVAL; | |
573 | dev_t devno; | |
574 | ||
575 | rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, name); | |
576 | if (rc) { | |
577 | pr_err("Unable to allocate coproc major number: %i\n", rc); | |
578 | return rc; | |
579 | } | |
580 | ||
581 | pr_devel("%s device allocated, dev [%i,%i]\n", name, | |
582 | MAJOR(coproc_device.devt), MINOR(coproc_device.devt)); | |
583 | ||
584 | coproc_device.class = class_create(mod, name); | |
585 | if (IS_ERR(coproc_device.class)) { | |
586 | rc = PTR_ERR(coproc_device.class); | |
587 | pr_err("Unable to create %s class %d\n", name, rc); | |
588 | goto err_class; | |
589 | } | |
590 | coproc_device.class->devnode = coproc_devnode; | |
591 | coproc_device.cop_type = cop_type; | |
1a0d0d5e | 592 | coproc_device.vops = vops; |
dda44eb2 HM |
593 | |
594 | coproc_fops.owner = mod; | |
595 | cdev_init(&coproc_device.cdev, &coproc_fops); | |
596 | ||
597 | devno = MKDEV(MAJOR(coproc_device.devt), 0); | |
598 | rc = cdev_add(&coproc_device.cdev, devno, 1); | |
599 | if (rc) { | |
600 | pr_err("cdev_add() failed %d\n", rc); | |
601 | goto err_cdev; | |
602 | } | |
603 | ||
604 | coproc_device.device = device_create(coproc_device.class, NULL, | |
605 | devno, NULL, name, MINOR(devno)); | |
606 | if (IS_ERR(coproc_device.device)) { | |
607 | rc = PTR_ERR(coproc_device.device); | |
608 | pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc); | |
609 | goto err; | |
610 | } | |
611 | ||
612 | pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno), | |
613 | MINOR(devno)); | |
614 | ||
615 | return 0; | |
616 | ||
617 | err: | |
618 | cdev_del(&coproc_device.cdev); | |
619 | err_cdev: | |
620 | class_destroy(coproc_device.class); | |
621 | err_class: | |
622 | unregister_chrdev_region(coproc_device.devt, 1); | |
623 | return rc; | |
624 | } | |
dda44eb2 HM |
625 | |
626 | void vas_unregister_coproc_api(void) | |
627 | { | |
628 | dev_t devno; | |
629 | ||
630 | cdev_del(&coproc_device.cdev); | |
631 | devno = MKDEV(MAJOR(coproc_device.devt), 0); | |
632 | device_destroy(coproc_device.class, devno); | |
633 | ||
634 | class_destroy(coproc_device.class); | |
635 | unregister_chrdev_region(coproc_device.devt, 1); | |
636 | } |