xref: /freebsd/sys/dev/netmap/netmap_freebsd.c (revision 6d732c66bca5da4d261577aad2c8ea84519b0bea)
1 /*
2  * Copyright (C) 2013-2014 Universita` di Pisa. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *   1. Redistributions of source code must retain the above copyright
8  *      notice, this list of conditions and the following disclaimer.
9  *   2. Redistributions in binary form must reproduce the above copyright
10  *      notice, this list of conditions and the following disclaimer in the
11  *      documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 /* $FreeBSD$ */
27 
28 #include <sys/types.h>
29 #include <sys/module.h>
30 #include <sys/errno.h>
31 #include <sys/param.h>  /* defines used in kernel.h */
32 #include <sys/kernel.h> /* types used in module initialization */
33 #include <sys/conf.h>	/* DEV_MODULE */
34 
35 #include <sys/rwlock.h>
36 
37 #include <vm/vm.h>      /* vtophys */
38 #include <vm/pmap.h>    /* vtophys */
39 #include <vm/vm_param.h>
40 #include <vm/vm_object.h>
41 #include <vm/vm_page.h>
42 #include <vm/vm_pager.h>
43 #include <vm/uma.h>
44 
45 
46 #include <sys/malloc.h>
47 #include <sys/socket.h> /* sockaddrs */
48 #include <sys/selinfo.h>
49 #include <net/if.h>
50 #include <net/if_var.h>
51 #include <machine/bus.h>        /* bus_dmamap_* */
52 
53 #include <net/netmap.h>
54 #include <dev/netmap/netmap_kern.h>
55 #include <dev/netmap/netmap_mem2.h>
56 
57 
58 /* ======================== FREEBSD-SPECIFIC ROUTINES ================== */
59 
60 /*
61  * Intercept the rx routine in the standard device driver.
62  * Second argument is non-zero to intercept, 0 to restore
63  */
64 int
65 netmap_catch_rx(struct netmap_adapter *na, int intercept)
66 {
67 	struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na;
68 	struct ifnet *ifp = na->ifp;
69 
70 	if (intercept) {
71 		if (gna->save_if_input) {
72 			D("cannot intercept again");
73 			return EINVAL; /* already set */
74 		}
75 		gna->save_if_input = ifp->if_input;
76 		ifp->if_input = generic_rx_handler;
77 	} else {
78 		if (!gna->save_if_input){
79 			D("cannot restore");
80 			return EINVAL;  /* not saved */
81 		}
82 		ifp->if_input = gna->save_if_input;
83 		gna->save_if_input = NULL;
84 	}
85 
86 	return 0;
87 }
88 
89 
90 /*
91  * Intercept the packet steering routine in the tx path,
92  * so that we can decide which queue is used for an mbuf.
93  * Second argument is non-zero to intercept, 0 to restore.
94  *
95  * actually we also need to redirect the if_transmit ?
96  *
97  * XXX see if FreeBSD has such a mechanism
98  */
99 void
100 netmap_catch_tx(struct netmap_generic_adapter *gna, int enable)
101 {
102 	struct netmap_adapter *na = &gna->up.up;
103 	struct ifnet *ifp = na->ifp;
104 
105 	if (enable) {
106 		na->if_transmit = ifp->if_transmit;
107 		ifp->if_transmit = netmap_transmit;
108 	} else {
109 		ifp->if_transmit = na->if_transmit;
110 	}
111 }
112 
113 
114 /* Transmit routine used by generic_netmap_txsync(). Returns 0 on success
115  * and non-zero on error (which may be packet drops or other errors).
116  * addr and len identify the netmap buffer, m is the (preallocated)
117  * mbuf to use for transmissions.
118  *
119  * We should add a reference to the mbuf so the m_freem() at the end
120  * of the transmission does not consume resources.
121  *
122  * On FreeBSD, and on multiqueue cards, we can force the queue using
123  *      if ((m->m_flags & M_FLOWID) != 0)
124  *              i = m->m_pkthdr.flowid % adapter->num_queues;
125  *      else
126  *              i = curcpu % adapter->num_queues;
127  *
128  */
129 int
130 generic_xmit_frame(struct ifnet *ifp, struct mbuf *m,
131 	void *addr, u_int len, u_int ring_nr)
132 {
133 	int ret;
134 
135 	m->m_len = m->m_pkthdr.len = 0;
136 
137 	// copy data to the mbuf
138 	m_copyback(m, 0, len, addr);
139 	// inc refcount. We are alone, so we can skip the atomic
140 	atomic_fetchadd_int(m->m_ext.ref_cnt, 1);
141 	m->m_flags |= M_FLOWID;
142 	m->m_pkthdr.flowid = ring_nr;
143 	m->m_pkthdr.rcvif = ifp; /* used for tx notification */
144 	ret = NA(ifp)->if_transmit(ifp, m);
145 	return ret;
146 }
147 
148 
149 /*
150  * The following two functions are empty until we have a generic
151  * way to extract the info from the ifp
152  */
153 int
154 generic_find_num_desc(struct ifnet *ifp, unsigned int *tx, unsigned int *rx)
155 {
156 	D("called");
157 	return 0;
158 }
159 
160 
161 void
162 generic_find_num_queues(struct ifnet *ifp, u_int *txq, u_int *rxq)
163 {
164 	D("called");
165 	*txq = 1;
166 	*rxq = 1;
167 }
168 
169 
170 void netmap_mitigation_init(struct netmap_generic_adapter *na)
171 {
172 	ND("called");
173 	na->mit_pending = 0;
174 }
175 
176 
177 void netmap_mitigation_start(struct netmap_generic_adapter *na)
178 {
179 	ND("called");
180 }
181 
182 
183 void netmap_mitigation_restart(struct netmap_generic_adapter *na)
184 {
185 	ND("called");
186 }
187 
188 
189 int netmap_mitigation_active(struct netmap_generic_adapter *na)
190 {
191 	ND("called");
192 	return 0;
193 }
194 
195 
196 void netmap_mitigation_cleanup(struct netmap_generic_adapter *na)
197 {
198 	ND("called");
199 }
200 
201 
202 /*
203  * In order to track whether pages are still mapped, we hook into
204  * the standard cdev_pager and intercept the constructor and
205  * destructor.
206  */
207 
208 struct netmap_vm_handle_t {
209 	struct cdev 		*dev;
210 	struct netmap_priv_d	*priv;
211 };
212 
213 
214 static int
215 netmap_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
216     vm_ooffset_t foff, struct ucred *cred, u_short *color)
217 {
218 	struct netmap_vm_handle_t *vmh = handle;
219 	D("handle %p size %jd prot %d foff %jd",
220 		handle, (intmax_t)size, prot, (intmax_t)foff);
221 	dev_ref(vmh->dev);
222 	return 0;
223 }
224 
225 
226 static void
227 netmap_dev_pager_dtor(void *handle)
228 {
229 	struct netmap_vm_handle_t *vmh = handle;
230 	struct cdev *dev = vmh->dev;
231 	struct netmap_priv_d *priv = vmh->priv;
232 	D("handle %p", handle);
233 	netmap_dtor(priv);
234 	free(vmh, M_DEVBUF);
235 	dev_rel(dev);
236 }
237 
238 
239 static int
240 netmap_dev_pager_fault(vm_object_t object, vm_ooffset_t offset,
241 	int prot, vm_page_t *mres)
242 {
243 	struct netmap_vm_handle_t *vmh = object->handle;
244 	struct netmap_priv_d *priv = vmh->priv;
245 	vm_paddr_t paddr;
246 	vm_page_t page;
247 	vm_memattr_t memattr;
248 	vm_pindex_t pidx;
249 
250 	ND("object %p offset %jd prot %d mres %p",
251 			object, (intmax_t)offset, prot, mres);
252 	memattr = object->memattr;
253 	pidx = OFF_TO_IDX(offset);
254 	paddr = netmap_mem_ofstophys(priv->np_mref, offset);
255 	if (paddr == 0)
256 		return VM_PAGER_FAIL;
257 
258 	if (((*mres)->flags & PG_FICTITIOUS) != 0) {
259 		/*
260 		 * If the passed in result page is a fake page, update it with
261 		 * the new physical address.
262 		 */
263 		page = *mres;
264 		vm_page_updatefake(page, paddr, memattr);
265 	} else {
266 		/*
267 		 * Replace the passed in reqpage page with our own fake page and
268 		 * free up the all of the original pages.
269 		 */
270 #ifndef VM_OBJECT_WUNLOCK	/* FreeBSD < 10.x */
271 #define VM_OBJECT_WUNLOCK VM_OBJECT_UNLOCK
272 #define VM_OBJECT_WLOCK	VM_OBJECT_LOCK
273 #endif /* VM_OBJECT_WUNLOCK */
274 
275 		VM_OBJECT_WUNLOCK(object);
276 		page = vm_page_getfake(paddr, memattr);
277 		VM_OBJECT_WLOCK(object);
278 		vm_page_lock(*mres);
279 		vm_page_free(*mres);
280 		vm_page_unlock(*mres);
281 		*mres = page;
282 		vm_page_insert(page, object, pidx);
283 	}
284 	page->valid = VM_PAGE_BITS_ALL;
285 	return (VM_PAGER_OK);
286 }
287 
288 
289 static struct cdev_pager_ops netmap_cdev_pager_ops = {
290 	.cdev_pg_ctor = netmap_dev_pager_ctor,
291 	.cdev_pg_dtor = netmap_dev_pager_dtor,
292 	.cdev_pg_fault = netmap_dev_pager_fault,
293 };
294 
295 
296 static int
297 netmap_mmap_single(struct cdev *cdev, vm_ooffset_t *foff,
298 	vm_size_t objsize,  vm_object_t *objp, int prot)
299 {
300 	int error;
301 	struct netmap_vm_handle_t *vmh;
302 	struct netmap_priv_d *priv;
303 	vm_object_t obj;
304 
305 	D("cdev %p foff %jd size %jd objp %p prot %d", cdev,
306 	    (intmax_t )*foff, (intmax_t )objsize, objp, prot);
307 
308 	vmh = malloc(sizeof(struct netmap_vm_handle_t), M_DEVBUF,
309 			      M_NOWAIT | M_ZERO);
310 	if (vmh == NULL)
311 		return ENOMEM;
312 	vmh->dev = cdev;
313 
314 	NMG_LOCK();
315 	error = devfs_get_cdevpriv((void**)&priv);
316 	if (error)
317 		goto err_unlock;
318 	vmh->priv = priv;
319 	priv->np_refcount++;
320 	NMG_UNLOCK();
321 
322 	error = netmap_get_memory(priv);
323 	if (error)
324 		goto err_deref;
325 
326 	obj = cdev_pager_allocate(vmh, OBJT_DEVICE,
327 		&netmap_cdev_pager_ops, objsize, prot,
328 		*foff, NULL);
329 	if (obj == NULL) {
330 		D("cdev_pager_allocate failed");
331 		error = EINVAL;
332 		goto err_deref;
333 	}
334 
335 	*objp = obj;
336 	return 0;
337 
338 err_deref:
339 	NMG_LOCK();
340 	priv->np_refcount--;
341 err_unlock:
342 	NMG_UNLOCK();
343 // err:
344 	free(vmh, M_DEVBUF);
345 	return error;
346 }
347 
348 
349 // XXX can we remove this ?
350 static int
351 netmap_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
352 {
353 	if (netmap_verbose)
354 		D("dev %p fflag 0x%x devtype %d td %p",
355 			dev, fflag, devtype, td);
356 	return 0;
357 }
358 
359 
360 static int
361 netmap_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
362 {
363 	struct netmap_priv_d *priv;
364 	int error;
365 
366 	(void)dev;
367 	(void)oflags;
368 	(void)devtype;
369 	(void)td;
370 
371 	// XXX wait or nowait ?
372 	priv = malloc(sizeof(struct netmap_priv_d), M_DEVBUF,
373 			      M_NOWAIT | M_ZERO);
374 	if (priv == NULL)
375 		return ENOMEM;
376 
377 	error = devfs_set_cdevpriv(priv, netmap_dtor);
378 	if (error)
379 	        return error;
380 
381 	priv->np_refcount = 1;
382 
383 	return 0;
384 }
385 
386 
387 struct cdevsw netmap_cdevsw = {
388 	.d_version = D_VERSION,
389 	.d_name = "netmap",
390 	.d_open = netmap_open,
391 	.d_mmap_single = netmap_mmap_single,
392 	.d_ioctl = netmap_ioctl,
393 	.d_poll = netmap_poll,
394 	.d_close = netmap_close,
395 };
396 
397 
398 /*
399  * Kernel entry point.
400  *
401  * Initialize/finalize the module and return.
402  *
403  * Return 0 on success, errno on failure.
404  */
405 static int
406 netmap_loader(__unused struct module *module, int event, __unused void *arg)
407 {
408 	int error = 0;
409 
410 	switch (event) {
411 	case MOD_LOAD:
412 		error = netmap_init();
413 		break;
414 
415 	case MOD_UNLOAD:
416 		netmap_fini();
417 		break;
418 
419 	default:
420 		error = EOPNOTSUPP;
421 		break;
422 	}
423 
424 	return (error);
425 }
426 
427 
428 DEV_MODULE(netmap, netmap_loader, NULL);
429