xref: /freebsd/sys/dev/ioat/ioat.c (revision 5ab1c5846ff41be24b1f6beb0317bf8258cd4409)
1 /*-
2  * Copyright (C) 2012 Intel Corporation
3  * All rights reserved.
4  * Copyright (C) 2018 Alexander Motin <mav@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include "opt_ddb.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/conf.h>
37 #include <sys/domainset.h>
38 #include <sys/fail.h>
39 #include <sys/ioccom.h>
40 #include <sys/kernel.h>
41 #include <sys/ktr.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/module.h>
45 #include <sys/mutex.h>
46 #include <sys/rman.h>
47 #include <sys/sbuf.h>
48 #include <sys/smp.h>
49 #include <sys/sysctl.h>
50 #include <sys/taskqueue.h>
51 #include <sys/time.h>
52 #include <dev/pci/pcireg.h>
53 #include <dev/pci/pcivar.h>
54 #include <machine/bus.h>
55 #include <machine/resource.h>
56 #include <machine/stdarg.h>
57 
58 #ifdef DDB
59 #include <ddb/ddb.h>
60 #endif
61 
62 #include "ioat.h"
63 #include "ioat_hw.h"
64 #include "ioat_internal.h"
65 
66 #ifndef	BUS_SPACE_MAXADDR_40BIT
67 #define	BUS_SPACE_MAXADDR_40BIT	MIN(BUS_SPACE_MAXADDR, 0xFFFFFFFFFFULL)
68 #endif
69 #ifndef	BUS_SPACE_MAXADDR_46BIT
70 #define	BUS_SPACE_MAXADDR_46BIT	MIN(BUS_SPACE_MAXADDR, 0x3FFFFFFFFFFFULL)
71 #endif
72 
73 static int ioat_probe(device_t device);
74 static int ioat_attach(device_t device);
75 static int ioat_detach(device_t device);
76 static int ioat_setup_intr(struct ioat_softc *ioat);
77 static int ioat_teardown_intr(struct ioat_softc *ioat);
78 static int ioat3_attach(device_t device);
79 static int ioat_start_channel(struct ioat_softc *ioat);
80 static int ioat_map_pci_bar(struct ioat_softc *ioat);
81 static void ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg,
82     int error);
83 static void ioat_interrupt_handler(void *arg);
84 static boolean_t ioat_model_resets_msix(struct ioat_softc *ioat);
85 static int chanerr_to_errno(uint32_t);
86 static void ioat_process_events(struct ioat_softc *ioat, boolean_t intr);
87 static inline uint32_t ioat_get_active(struct ioat_softc *ioat);
88 static inline uint32_t ioat_get_ring_space(struct ioat_softc *ioat);
89 static void ioat_free_ring(struct ioat_softc *, uint32_t size,
90     struct ioat_descriptor *);
91 static int ioat_reserve_space(struct ioat_softc *, uint32_t, int mflags);
92 static union ioat_hw_descriptor *ioat_get_descriptor(struct ioat_softc *,
93     uint32_t index);
94 static struct ioat_descriptor *ioat_get_ring_entry(struct ioat_softc *,
95     uint32_t index);
96 static void ioat_halted_debug(struct ioat_softc *, uint32_t);
97 static void ioat_poll_timer_callback(void *arg);
98 static void dump_descriptor(void *hw_desc);
99 static void ioat_submit_single(struct ioat_softc *ioat);
100 static void ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg,
101     int error);
102 static int ioat_reset_hw(struct ioat_softc *ioat);
103 static void ioat_reset_hw_task(void *, int);
104 static void ioat_setup_sysctl(device_t device);
105 static int sysctl_handle_reset(SYSCTL_HANDLER_ARGS);
106 static void ioat_get(struct ioat_softc *);
107 static void ioat_put(struct ioat_softc *);
108 static void ioat_drain_locked(struct ioat_softc *);
109 
110 #define	ioat_log_message(v, ...) do {					\
111 	if ((v) <= g_ioat_debug_level) {				\
112 		device_printf(ioat->device, __VA_ARGS__);		\
113 	}								\
114 } while (0)
115 
116 MALLOC_DEFINE(M_IOAT, "ioat", "ioat driver memory allocations");
117 SYSCTL_NODE(_hw, OID_AUTO, ioat, CTLFLAG_RD, 0, "ioat node");
118 
119 static int g_force_legacy_interrupts;
120 SYSCTL_INT(_hw_ioat, OID_AUTO, force_legacy_interrupts, CTLFLAG_RDTUN,
121     &g_force_legacy_interrupts, 0, "Set to non-zero to force MSI-X disabled");
122 
123 int g_ioat_debug_level = 0;
124 SYSCTL_INT(_hw_ioat, OID_AUTO, debug_level, CTLFLAG_RWTUN, &g_ioat_debug_level,
125     0, "Set log level (0-3) for ioat(4). Higher is more verbose.");
126 
127 unsigned g_ioat_ring_order = 13;
128 SYSCTL_UINT(_hw_ioat, OID_AUTO, ring_order, CTLFLAG_RDTUN, &g_ioat_ring_order,
129     0, "Set IOAT ring order.  (1 << this) == ring size.");
130 
131 /*
132  * OS <-> Driver interface structures
133  */
134 static device_method_t ioat_pci_methods[] = {
135 	/* Device interface */
136 	DEVMETHOD(device_probe,     ioat_probe),
137 	DEVMETHOD(device_attach,    ioat_attach),
138 	DEVMETHOD(device_detach,    ioat_detach),
139 	DEVMETHOD_END
140 };
141 
142 static driver_t ioat_pci_driver = {
143 	"ioat",
144 	ioat_pci_methods,
145 	sizeof(struct ioat_softc),
146 };
147 
148 static devclass_t ioat_devclass;
149 DRIVER_MODULE(ioat, pci, ioat_pci_driver, ioat_devclass, 0, 0);
150 MODULE_VERSION(ioat, 1);
151 
152 /*
153  * Private data structures
154  */
155 static struct ioat_softc *ioat_channel[IOAT_MAX_CHANNELS];
156 static unsigned ioat_channel_index = 0;
157 SYSCTL_UINT(_hw_ioat, OID_AUTO, channels, CTLFLAG_RD, &ioat_channel_index, 0,
158     "Number of IOAT channels attached");
159 static struct mtx ioat_list_mtx;
160 MTX_SYSINIT(ioat_list_mtx, &ioat_list_mtx, "ioat list mtx", MTX_DEF);
161 
162 static struct _pcsid
163 {
164 	u_int32_t   type;
165 	const char  *desc;
166 } pci_ids[] = {
167 	{ 0x34308086, "TBG IOAT Ch0" },
168 	{ 0x34318086, "TBG IOAT Ch1" },
169 	{ 0x34328086, "TBG IOAT Ch2" },
170 	{ 0x34338086, "TBG IOAT Ch3" },
171 	{ 0x34298086, "TBG IOAT Ch4" },
172 	{ 0x342a8086, "TBG IOAT Ch5" },
173 	{ 0x342b8086, "TBG IOAT Ch6" },
174 	{ 0x342c8086, "TBG IOAT Ch7" },
175 
176 	{ 0x37108086, "JSF IOAT Ch0" },
177 	{ 0x37118086, "JSF IOAT Ch1" },
178 	{ 0x37128086, "JSF IOAT Ch2" },
179 	{ 0x37138086, "JSF IOAT Ch3" },
180 	{ 0x37148086, "JSF IOAT Ch4" },
181 	{ 0x37158086, "JSF IOAT Ch5" },
182 	{ 0x37168086, "JSF IOAT Ch6" },
183 	{ 0x37178086, "JSF IOAT Ch7" },
184 	{ 0x37188086, "JSF IOAT Ch0 (RAID)" },
185 	{ 0x37198086, "JSF IOAT Ch1 (RAID)" },
186 
187 	{ 0x3c208086, "SNB IOAT Ch0" },
188 	{ 0x3c218086, "SNB IOAT Ch1" },
189 	{ 0x3c228086, "SNB IOAT Ch2" },
190 	{ 0x3c238086, "SNB IOAT Ch3" },
191 	{ 0x3c248086, "SNB IOAT Ch4" },
192 	{ 0x3c258086, "SNB IOAT Ch5" },
193 	{ 0x3c268086, "SNB IOAT Ch6" },
194 	{ 0x3c278086, "SNB IOAT Ch7" },
195 	{ 0x3c2e8086, "SNB IOAT Ch0 (RAID)" },
196 	{ 0x3c2f8086, "SNB IOAT Ch1 (RAID)" },
197 
198 	{ 0x0e208086, "IVB IOAT Ch0" },
199 	{ 0x0e218086, "IVB IOAT Ch1" },
200 	{ 0x0e228086, "IVB IOAT Ch2" },
201 	{ 0x0e238086, "IVB IOAT Ch3" },
202 	{ 0x0e248086, "IVB IOAT Ch4" },
203 	{ 0x0e258086, "IVB IOAT Ch5" },
204 	{ 0x0e268086, "IVB IOAT Ch6" },
205 	{ 0x0e278086, "IVB IOAT Ch7" },
206 	{ 0x0e2e8086, "IVB IOAT Ch0 (RAID)" },
207 	{ 0x0e2f8086, "IVB IOAT Ch1 (RAID)" },
208 
209 	{ 0x2f208086, "HSW IOAT Ch0" },
210 	{ 0x2f218086, "HSW IOAT Ch1" },
211 	{ 0x2f228086, "HSW IOAT Ch2" },
212 	{ 0x2f238086, "HSW IOAT Ch3" },
213 	{ 0x2f248086, "HSW IOAT Ch4" },
214 	{ 0x2f258086, "HSW IOAT Ch5" },
215 	{ 0x2f268086, "HSW IOAT Ch6" },
216 	{ 0x2f278086, "HSW IOAT Ch7" },
217 	{ 0x2f2e8086, "HSW IOAT Ch0 (RAID)" },
218 	{ 0x2f2f8086, "HSW IOAT Ch1 (RAID)" },
219 
220 	{ 0x0c508086, "BWD IOAT Ch0" },
221 	{ 0x0c518086, "BWD IOAT Ch1" },
222 	{ 0x0c528086, "BWD IOAT Ch2" },
223 	{ 0x0c538086, "BWD IOAT Ch3" },
224 
225 	{ 0x6f508086, "BDXDE IOAT Ch0" },
226 	{ 0x6f518086, "BDXDE IOAT Ch1" },
227 	{ 0x6f528086, "BDXDE IOAT Ch2" },
228 	{ 0x6f538086, "BDXDE IOAT Ch3" },
229 
230 	{ 0x6f208086, "BDX IOAT Ch0" },
231 	{ 0x6f218086, "BDX IOAT Ch1" },
232 	{ 0x6f228086, "BDX IOAT Ch2" },
233 	{ 0x6f238086, "BDX IOAT Ch3" },
234 	{ 0x6f248086, "BDX IOAT Ch4" },
235 	{ 0x6f258086, "BDX IOAT Ch5" },
236 	{ 0x6f268086, "BDX IOAT Ch6" },
237 	{ 0x6f278086, "BDX IOAT Ch7" },
238 	{ 0x6f2e8086, "BDX IOAT Ch0 (RAID)" },
239 	{ 0x6f2f8086, "BDX IOAT Ch1 (RAID)" },
240 
241 	{ 0x20218086, "SKX IOAT" },
242 };
243 
244 MODULE_PNP_INFO("W32:vendor/device;D:#", pci, ioat, pci_ids,
245     nitems(pci_ids));
246 
247 /*
248  * OS <-> Driver linkage functions
249  */
250 static int
251 ioat_probe(device_t device)
252 {
253 	struct _pcsid *ep;
254 	u_int32_t type;
255 
256 	type = pci_get_devid(device);
257 	for (ep = pci_ids; ep < &pci_ids[nitems(pci_ids)]; ep++) {
258 		if (ep->type == type) {
259 			device_set_desc(device, ep->desc);
260 			return (0);
261 		}
262 	}
263 	return (ENXIO);
264 }
265 
266 static int
267 ioat_attach(device_t device)
268 {
269 	struct ioat_softc *ioat;
270 	int error, i;
271 
272 	ioat = DEVICE2SOFTC(device);
273 	ioat->device = device;
274 	if (bus_get_domain(device, &ioat->domain) != 0)
275 		ioat->domain = 0;
276 	ioat->cpu = CPU_FFS(&cpuset_domain[ioat->domain]) - 1;
277 	if (ioat->cpu < 0)
278 		ioat->cpu = CPU_FIRST();
279 
280 	error = ioat_map_pci_bar(ioat);
281 	if (error != 0)
282 		goto err;
283 
284 	ioat->version = ioat_read_cbver(ioat);
285 	if (ioat->version < IOAT_VER_3_0) {
286 		error = ENODEV;
287 		goto err;
288 	}
289 
290 	error = ioat3_attach(device);
291 	if (error != 0)
292 		goto err;
293 
294 	error = pci_enable_busmaster(device);
295 	if (error != 0)
296 		goto err;
297 
298 	error = ioat_setup_intr(ioat);
299 	if (error != 0)
300 		goto err;
301 
302 	error = ioat_reset_hw(ioat);
303 	if (error != 0)
304 		goto err;
305 
306 	ioat_process_events(ioat, FALSE);
307 	ioat_setup_sysctl(device);
308 
309 	mtx_lock(&ioat_list_mtx);
310 	for (i = 0; i < IOAT_MAX_CHANNELS; i++) {
311 		if (ioat_channel[i] == NULL)
312 			break;
313 	}
314 	if (i >= IOAT_MAX_CHANNELS) {
315 		mtx_unlock(&ioat_list_mtx);
316 		device_printf(device, "Too many I/OAT devices in system\n");
317 		error = ENXIO;
318 		goto err;
319 	}
320 	ioat->chan_idx = i;
321 	ioat_channel[i] = ioat;
322 	if (i >= ioat_channel_index)
323 		ioat_channel_index = i + 1;
324 	mtx_unlock(&ioat_list_mtx);
325 
326 	ioat_test_attach();
327 
328 err:
329 	if (error != 0)
330 		ioat_detach(device);
331 	return (error);
332 }
333 
334 static inline int
335 ioat_bus_dmamap_destroy(struct ioat_softc *ioat, const char *func,
336     bus_dma_tag_t dmat, bus_dmamap_t map)
337 {
338 	int error;
339 
340 	error = bus_dmamap_destroy(dmat, map);
341 	if (error != 0) {
342 		ioat_log_message(0,
343 		    "%s: bus_dmamap_destroy failed %d\n", func, error);
344 	}
345 
346 	return (error);
347 }
348 
349 static int
350 ioat_detach(device_t device)
351 {
352 	struct ioat_softc *ioat;
353 	int i, error;
354 
355 	ioat = DEVICE2SOFTC(device);
356 
357 	mtx_lock(&ioat_list_mtx);
358 	ioat_channel[ioat->chan_idx] = NULL;
359 	while (ioat_channel_index > 0 &&
360 	    ioat_channel[ioat_channel_index - 1] == NULL)
361 		ioat_channel_index--;
362 	mtx_unlock(&ioat_list_mtx);
363 
364 	ioat_test_detach();
365 	taskqueue_drain(taskqueue_thread, &ioat->reset_task);
366 
367 	mtx_lock(&ioat->submit_lock);
368 	ioat->quiescing = TRUE;
369 	ioat->destroying = TRUE;
370 	wakeup(&ioat->quiescing);
371 	wakeup(&ioat->resetting);
372 
373 	ioat_drain_locked(ioat);
374 	mtx_unlock(&ioat->submit_lock);
375 	mtx_lock(&ioat->cleanup_lock);
376 	while (ioat_get_active(ioat) > 0)
377 		msleep(&ioat->tail, &ioat->cleanup_lock, 0, "ioat_drain", 1);
378 	mtx_unlock(&ioat->cleanup_lock);
379 
380 	ioat_teardown_intr(ioat);
381 	callout_drain(&ioat->poll_timer);
382 
383 	pci_disable_busmaster(device);
384 
385 	if (ioat->pci_resource != NULL)
386 		bus_release_resource(device, SYS_RES_MEMORY,
387 		    ioat->pci_resource_id, ioat->pci_resource);
388 
389 	if (ioat->data_tag != NULL) {
390 		for (i = 0; i < 1 << ioat->ring_size_order; i++) {
391 			error = ioat_bus_dmamap_destroy(ioat, __func__,
392 			    ioat->data_tag, ioat->ring[i].src_dmamap);
393 			if (error != 0)
394 				return (error);
395 		}
396 		for (i = 0; i < 1 << ioat->ring_size_order; i++) {
397 			error = ioat_bus_dmamap_destroy(ioat, __func__,
398 			    ioat->data_tag, ioat->ring[i].dst_dmamap);
399 			if (error != 0)
400 				return (error);
401 		}
402 
403 		for (i = 0; i < 1 << ioat->ring_size_order; i++) {
404 			error = ioat_bus_dmamap_destroy(ioat, __func__,
405 			    ioat->data_tag, ioat->ring[i].src2_dmamap);
406 			if (error != 0)
407 				return (error);
408 		}
409 		for (i = 0; i < 1 << ioat->ring_size_order; i++) {
410 			error = ioat_bus_dmamap_destroy(ioat, __func__,
411 			    ioat->data_tag, ioat->ring[i].dst2_dmamap);
412 			if (error != 0)
413 				return (error);
414 		}
415 
416 		bus_dma_tag_destroy(ioat->data_tag);
417 	}
418 
419 	if (ioat->ring != NULL)
420 		ioat_free_ring(ioat, 1 << ioat->ring_size_order, ioat->ring);
421 
422 	if (ioat->comp_update != NULL) {
423 		bus_dmamap_unload(ioat->comp_update_tag, ioat->comp_update_map);
424 		bus_dmamem_free(ioat->comp_update_tag, ioat->comp_update,
425 		    ioat->comp_update_map);
426 		bus_dma_tag_destroy(ioat->comp_update_tag);
427 	}
428 
429 	if (ioat->hw_desc_ring != NULL) {
430 		bus_dmamap_unload(ioat->hw_desc_tag, ioat->hw_desc_map);
431 		bus_dmamem_free(ioat->hw_desc_tag, ioat->hw_desc_ring,
432 		    ioat->hw_desc_map);
433 		bus_dma_tag_destroy(ioat->hw_desc_tag);
434 	}
435 
436 	return (0);
437 }
438 
439 static int
440 ioat_teardown_intr(struct ioat_softc *ioat)
441 {
442 
443 	if (ioat->tag != NULL)
444 		bus_teardown_intr(ioat->device, ioat->res, ioat->tag);
445 
446 	if (ioat->res != NULL)
447 		bus_release_resource(ioat->device, SYS_RES_IRQ,
448 		    rman_get_rid(ioat->res), ioat->res);
449 
450 	pci_release_msi(ioat->device);
451 	return (0);
452 }
453 
454 static int
455 ioat_start_channel(struct ioat_softc *ioat)
456 {
457 	struct ioat_dma_hw_descriptor *hw_desc;
458 	struct ioat_descriptor *desc;
459 	struct bus_dmadesc *dmadesc;
460 	uint64_t status;
461 	uint32_t chanerr;
462 	int i;
463 
464 	ioat_acquire(&ioat->dmaengine);
465 
466 	/* Submit 'NULL' operation manually to avoid quiescing flag */
467 	desc = ioat_get_ring_entry(ioat, ioat->head);
468 	hw_desc = &ioat_get_descriptor(ioat, ioat->head)->dma;
469 	dmadesc = &desc->bus_dmadesc;
470 
471 	dmadesc->callback_fn = NULL;
472 	dmadesc->callback_arg = NULL;
473 
474 	hw_desc->u.control_raw = 0;
475 	hw_desc->u.control_generic.op = IOAT_OP_COPY;
476 	hw_desc->u.control_generic.completion_update = 1;
477 	hw_desc->size = 8;
478 	hw_desc->src_addr = 0;
479 	hw_desc->dest_addr = 0;
480 	hw_desc->u.control.null = 1;
481 
482 	ioat_submit_single(ioat);
483 	ioat_release(&ioat->dmaengine);
484 
485 	for (i = 0; i < 100; i++) {
486 		DELAY(1);
487 		status = ioat_get_chansts(ioat);
488 		if (is_ioat_idle(status))
489 			return (0);
490 	}
491 
492 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
493 	ioat_log_message(0, "could not start channel: "
494 	    "status = %#jx error = %b\n", (uintmax_t)status, (int)chanerr,
495 	    IOAT_CHANERR_STR);
496 	return (ENXIO);
497 }
498 
499 /*
500  * Initialize Hardware
501  */
502 static int
503 ioat3_attach(device_t device)
504 {
505 	struct ioat_softc *ioat;
506 	struct ioat_descriptor *ring;
507 	struct ioat_dma_hw_descriptor *dma_hw_desc;
508 	void *hw_desc;
509 	bus_addr_t lowaddr;
510 	size_t ringsz;
511 	int i, num_descriptors;
512 	int error;
513 	uint8_t xfercap;
514 
515 	error = 0;
516 	ioat = DEVICE2SOFTC(device);
517 	ioat->capabilities = ioat_read_dmacapability(ioat);
518 
519 	ioat_log_message(0, "Capabilities: %b\n", (int)ioat->capabilities,
520 	    IOAT_DMACAP_STR);
521 
522 	xfercap = ioat_read_xfercap(ioat);
523 	ioat->max_xfer_size = 1 << xfercap;
524 
525 	ioat->intrdelay_supported = (ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) &
526 	    IOAT_INTRDELAY_SUPPORTED) != 0;
527 	if (ioat->intrdelay_supported)
528 		ioat->intrdelay_max = IOAT_INTRDELAY_US_MASK;
529 
530 	/* TODO: need to check DCA here if we ever do XOR/PQ */
531 
532 	mtx_init(&ioat->submit_lock, "ioat_submit", NULL, MTX_DEF);
533 	mtx_init(&ioat->cleanup_lock, "ioat_cleanup", NULL, MTX_DEF);
534 	callout_init(&ioat->poll_timer, 1);
535 	TASK_INIT(&ioat->reset_task, 0, ioat_reset_hw_task, ioat);
536 
537 	/* Establish lock order for Witness */
538 	mtx_lock(&ioat->cleanup_lock);
539 	mtx_lock(&ioat->submit_lock);
540 	mtx_unlock(&ioat->submit_lock);
541 	mtx_unlock(&ioat->cleanup_lock);
542 
543 	ioat->is_submitter_processing = FALSE;
544 
545 	if (ioat->version >= IOAT_VER_3_3)
546 		lowaddr = BUS_SPACE_MAXADDR_48BIT;
547 	else if (ioat->version >= IOAT_VER_3_2)
548 		lowaddr = BUS_SPACE_MAXADDR_46BIT;
549 	else
550 		lowaddr = BUS_SPACE_MAXADDR_40BIT;
551 
552 	error = bus_dma_tag_create(bus_get_dma_tag(ioat->device),
553 	    sizeof(uint64_t), 0x0, lowaddr, BUS_SPACE_MAXADDR, NULL, NULL,
554 	    sizeof(uint64_t), 1, sizeof(uint64_t), 0, NULL, NULL,
555 	    &ioat->comp_update_tag);
556 	if (error != 0)
557 		return (error);
558 
559 	error = bus_dmamem_alloc(ioat->comp_update_tag,
560 	    (void **)&ioat->comp_update, BUS_DMA_ZERO | BUS_DMA_WAITOK,
561 	    &ioat->comp_update_map);
562 	if (error != 0)
563 		return (error);
564 
565 	error = bus_dmamap_load(ioat->comp_update_tag, ioat->comp_update_map,
566 	    ioat->comp_update, sizeof(uint64_t), ioat_comp_update_map, ioat,
567 	    BUS_DMA_NOWAIT);
568 	if (error != 0)
569 		return (error);
570 
571 	ioat->ring_size_order = g_ioat_ring_order;
572 	num_descriptors = 1 << ioat->ring_size_order;
573 	ringsz = sizeof(struct ioat_dma_hw_descriptor) * num_descriptors;
574 
575 	error = bus_dma_tag_create(bus_get_dma_tag(ioat->device),
576 	    2 * 1024 * 1024, 0x0, lowaddr, BUS_SPACE_MAXADDR, NULL, NULL,
577 	    ringsz, 1, ringsz, 0, NULL, NULL, &ioat->hw_desc_tag);
578 	if (error != 0)
579 		return (error);
580 
581 	error = bus_dmamem_alloc(ioat->hw_desc_tag, &hw_desc,
582 	    BUS_DMA_ZERO | BUS_DMA_WAITOK, &ioat->hw_desc_map);
583 	if (error != 0)
584 		return (error);
585 
586 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
587 	    ringsz, ioat_dmamap_cb, &ioat->hw_desc_bus_addr, BUS_DMA_NOWAIT);
588 	if (error)
589 		return (error);
590 
591 	ioat->hw_desc_ring = hw_desc;
592 
593 	error = bus_dma_tag_create(bus_get_dma_tag(ioat->device),
594 	    1, 0, lowaddr, BUS_SPACE_MAXADDR, NULL, NULL,
595 	    ioat->max_xfer_size, 1, ioat->max_xfer_size, 0, NULL, NULL,
596 	    &ioat->data_tag);
597 	if (error != 0)
598 		return (error);
599 	ioat->ring = malloc_domainset(num_descriptors * sizeof(*ring), M_IOAT,
600 	    DOMAINSET_PREF(ioat->domain), M_ZERO | M_WAITOK);
601 
602 	ring = ioat->ring;
603 	for (i = 0; i < num_descriptors; i++) {
604 		memset(&ring[i].bus_dmadesc, 0, sizeof(ring[i].bus_dmadesc));
605 		ring[i].id = i;
606 		error = bus_dmamap_create(ioat->data_tag, 0,
607                     &ring[i].src_dmamap);
608 		if (error != 0) {
609 			ioat_log_message(0,
610 			    "%s: bus_dmamap_create failed %d\n", __func__,
611 			    error);
612 			return (error);
613 		}
614 		error = bus_dmamap_create(ioat->data_tag, 0,
615                     &ring[i].dst_dmamap);
616 		if (error != 0) {
617 			ioat_log_message(0,
618 			    "%s: bus_dmamap_create failed %d\n", __func__,
619 			    error);
620 			return (error);
621 		}
622 		error = bus_dmamap_create(ioat->data_tag, 0,
623                     &ring[i].src2_dmamap);
624 		if (error != 0) {
625 			ioat_log_message(0,
626 			    "%s: bus_dmamap_create failed %d\n", __func__,
627 			    error);
628 			return (error);
629 		}
630 		error = bus_dmamap_create(ioat->data_tag, 0,
631                     &ring[i].dst2_dmamap);
632 		if (error != 0) {
633 			ioat_log_message(0,
634 			    "%s: bus_dmamap_create failed %d\n", __func__,
635 			    error);
636 			return (error);
637 		}
638 	}
639 
640 	for (i = 0; i < num_descriptors; i++) {
641 		dma_hw_desc = &ioat->hw_desc_ring[i].dma;
642 		dma_hw_desc->next = RING_PHYS_ADDR(ioat, i + 1);
643 	}
644 
645 	ioat->tail = ioat->head = 0;
646 	*ioat->comp_update = ioat->last_seen =
647 	    RING_PHYS_ADDR(ioat, ioat->tail - 1);
648 	return (0);
649 }
650 
651 static int
652 ioat_map_pci_bar(struct ioat_softc *ioat)
653 {
654 
655 	ioat->pci_resource_id = PCIR_BAR(0);
656 	ioat->pci_resource = bus_alloc_resource_any(ioat->device,
657 	    SYS_RES_MEMORY, &ioat->pci_resource_id, RF_ACTIVE);
658 
659 	if (ioat->pci_resource == NULL) {
660 		ioat_log_message(0, "unable to allocate pci resource\n");
661 		return (ENODEV);
662 	}
663 
664 	ioat->pci_bus_tag = rman_get_bustag(ioat->pci_resource);
665 	ioat->pci_bus_handle = rman_get_bushandle(ioat->pci_resource);
666 	return (0);
667 }
668 
669 static void
670 ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
671 {
672 	struct ioat_softc *ioat = arg;
673 
674 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
675 	ioat->comp_update_bus_addr = seg[0].ds_addr;
676 }
677 
678 static void
679 ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
680 {
681 	bus_addr_t *baddr;
682 
683 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
684 	baddr = arg;
685 	*baddr = segs->ds_addr;
686 }
687 
688 /*
689  * Interrupt setup and handlers
690  */
691 static int
692 ioat_setup_intr(struct ioat_softc *ioat)
693 {
694 	uint32_t num_vectors;
695 	int error;
696 	boolean_t use_msix;
697 	boolean_t force_legacy_interrupts;
698 
699 	use_msix = FALSE;
700 	force_legacy_interrupts = FALSE;
701 
702 	if (!g_force_legacy_interrupts && pci_msix_count(ioat->device) >= 1) {
703 		num_vectors = 1;
704 		pci_alloc_msix(ioat->device, &num_vectors);
705 		if (num_vectors == 1)
706 			use_msix = TRUE;
707 	}
708 
709 	if (use_msix) {
710 		ioat->rid = 1;
711 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
712 		    &ioat->rid, RF_ACTIVE);
713 	} else {
714 		ioat->rid = 0;
715 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
716 		    &ioat->rid, RF_SHAREABLE | RF_ACTIVE);
717 	}
718 	if (ioat->res == NULL) {
719 		ioat_log_message(0, "bus_alloc_resource failed\n");
720 		return (ENOMEM);
721 	}
722 
723 	ioat->tag = NULL;
724 	error = bus_setup_intr(ioat->device, ioat->res, INTR_MPSAFE |
725 	    INTR_TYPE_MISC, NULL, ioat_interrupt_handler, ioat, &ioat->tag);
726 	if (error != 0) {
727 		ioat_log_message(0, "bus_setup_intr failed\n");
728 		return (error);
729 	}
730 
731 	ioat_write_intrctrl(ioat, IOAT_INTRCTRL_MASTER_INT_EN);
732 	return (0);
733 }
734 
735 static boolean_t
736 ioat_model_resets_msix(struct ioat_softc *ioat)
737 {
738 	u_int32_t pciid;
739 
740 	pciid = pci_get_devid(ioat->device);
741 	switch (pciid) {
742 		/* BWD: */
743 	case 0x0c508086:
744 	case 0x0c518086:
745 	case 0x0c528086:
746 	case 0x0c538086:
747 		/* BDXDE: */
748 	case 0x6f508086:
749 	case 0x6f518086:
750 	case 0x6f528086:
751 	case 0x6f538086:
752 		return (TRUE);
753 	}
754 
755 	return (FALSE);
756 }
757 
758 static void
759 ioat_interrupt_handler(void *arg)
760 {
761 	struct ioat_softc *ioat = arg;
762 
763 	ioat->stats.interrupts++;
764 	ioat_process_events(ioat, TRUE);
765 }
766 
767 static int
768 chanerr_to_errno(uint32_t chanerr)
769 {
770 
771 	if (chanerr == 0)
772 		return (0);
773 	if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
774 		return (EFAULT);
775 	if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
776 		return (EIO);
777 	/* This one is probably our fault: */
778 	if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
779 		return (EIO);
780 	return (EIO);
781 }
782 
783 static void
784 ioat_process_events(struct ioat_softc *ioat, boolean_t intr)
785 {
786 	struct ioat_descriptor *desc;
787 	struct bus_dmadesc *dmadesc;
788 	uint64_t comp_update, status;
789 	uint32_t completed, chanerr;
790 	int error;
791 
792 	mtx_lock(&ioat->cleanup_lock);
793 
794 	/*
795 	 * Don't run while the hardware is being reset.  Reset is responsible
796 	 * for blocking new work and draining & completing existing work, so
797 	 * there is nothing to do until new work is queued after reset anyway.
798 	 */
799 	if (ioat->resetting_cleanup) {
800 		mtx_unlock(&ioat->cleanup_lock);
801 		return;
802 	}
803 
804 	completed = 0;
805 	comp_update = *ioat->comp_update;
806 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
807 
808 	if (status < ioat->hw_desc_bus_addr ||
809 	    status >= ioat->hw_desc_bus_addr + (1 << ioat->ring_size_order) *
810 	    sizeof(struct ioat_generic_hw_descriptor))
811 		panic("Bogus completion address %jx (channel %u)",
812 		    (uintmax_t)status, ioat->chan_idx);
813 
814 	if (status == ioat->last_seen) {
815 		/*
816 		 * If we landed in process_events and nothing has been
817 		 * completed, check for a timeout due to channel halt.
818 		 */
819 		goto out;
820 	}
821 	CTR4(KTR_IOAT, "%s channel=%u hw_status=0x%lx last_seen=0x%lx",
822 	    __func__, ioat->chan_idx, comp_update, ioat->last_seen);
823 
824 	while (RING_PHYS_ADDR(ioat, ioat->tail - 1) != status) {
825 		desc = ioat_get_ring_entry(ioat, ioat->tail);
826 		dmadesc = &desc->bus_dmadesc;
827 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) ok  cb %p(%p)",
828 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
829 		    dmadesc->callback_arg);
830 
831 		bus_dmamap_unload(ioat->data_tag, desc->src_dmamap);
832 		bus_dmamap_unload(ioat->data_tag, desc->dst_dmamap);
833 		bus_dmamap_unload(ioat->data_tag, desc->src2_dmamap);
834 		bus_dmamap_unload(ioat->data_tag, desc->dst2_dmamap);
835 
836 		if (dmadesc->callback_fn != NULL)
837 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
838 
839 		completed++;
840 		ioat->tail++;
841 	}
842 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
843 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
844 
845 	if (completed != 0) {
846 		ioat->last_seen = RING_PHYS_ADDR(ioat, ioat->tail - 1);
847 		ioat->stats.descriptors_processed += completed;
848 		wakeup(&ioat->tail);
849 	}
850 
851 out:
852 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
853 	mtx_unlock(&ioat->cleanup_lock);
854 
855 	/*
856 	 * The device doesn't seem to reliably push suspend/halt statuses to
857 	 * the channel completion memory address, so poll the device register
858 	 * here.  For performance reasons skip it on interrupts, do it only
859 	 * on much more rare polling events.
860 	 */
861 	if (!intr)
862 		comp_update = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
863 	if (!is_ioat_halted(comp_update) && !is_ioat_suspended(comp_update))
864 		return;
865 
866 	ioat->stats.channel_halts++;
867 
868 	/*
869 	 * Fatal programming error on this DMA channel.  Flush any outstanding
870 	 * work with error status and restart the engine.
871 	 */
872 	mtx_lock(&ioat->submit_lock);
873 	ioat->quiescing = TRUE;
874 	mtx_unlock(&ioat->submit_lock);
875 
876 	/*
877 	 * This is safe to do here because the submit queue is quiesced.  We
878 	 * know that we will drain all outstanding events, so ioat_reset_hw
879 	 * can't deadlock. It is necessary to protect other ioat_process_event
880 	 * threads from racing ioat_reset_hw, reading an indeterminate hw
881 	 * state, and attempting to continue issuing completions.
882 	 */
883 	mtx_lock(&ioat->cleanup_lock);
884 	ioat->resetting_cleanup = TRUE;
885 
886 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
887 	if (1 <= g_ioat_debug_level)
888 		ioat_halted_debug(ioat, chanerr);
889 	ioat->stats.last_halt_chanerr = chanerr;
890 
891 	while (ioat_get_active(ioat) > 0) {
892 		desc = ioat_get_ring_entry(ioat, ioat->tail);
893 		dmadesc = &desc->bus_dmadesc;
894 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) err cb %p(%p)",
895 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
896 		    dmadesc->callback_arg);
897 
898 		if (dmadesc->callback_fn != NULL)
899 			dmadesc->callback_fn(dmadesc->callback_arg,
900 			    chanerr_to_errno(chanerr));
901 
902 		ioat->tail++;
903 		ioat->stats.descriptors_processed++;
904 		ioat->stats.descriptors_error++;
905 	}
906 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
907 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
908 
909 	/* Clear error status */
910 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
911 
912 	mtx_unlock(&ioat->cleanup_lock);
913 
914 	ioat_log_message(0, "Resetting channel to recover from error\n");
915 	error = taskqueue_enqueue(taskqueue_thread, &ioat->reset_task);
916 	KASSERT(error == 0,
917 	    ("%s: taskqueue_enqueue failed: %d", __func__, error));
918 }
919 
920 static void
921 ioat_reset_hw_task(void *ctx, int pending __unused)
922 {
923 	struct ioat_softc *ioat;
924 	int error;
925 
926 	ioat = ctx;
927 	ioat_log_message(1, "%s: Resetting channel\n", __func__);
928 
929 	error = ioat_reset_hw(ioat);
930 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
931 	(void)error;
932 }
933 
934 /*
935  * User API functions
936  */
937 unsigned
938 ioat_get_nchannels(void)
939 {
940 
941 	return (ioat_channel_index);
942 }
943 
944 bus_dmaengine_t
945 ioat_get_dmaengine(uint32_t index, int flags)
946 {
947 	struct ioat_softc *ioat;
948 
949 	KASSERT((flags & ~(M_NOWAIT | M_WAITOK)) == 0,
950 	    ("invalid flags: 0x%08x", flags));
951 	KASSERT((flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK),
952 	    ("invalid wait | nowait"));
953 
954 	mtx_lock(&ioat_list_mtx);
955 	if (index >= ioat_channel_index ||
956 	    (ioat = ioat_channel[index]) == NULL) {
957 		mtx_unlock(&ioat_list_mtx);
958 		return (NULL);
959 	}
960 	mtx_lock(&ioat->submit_lock);
961 	mtx_unlock(&ioat_list_mtx);
962 
963 	if (ioat->destroying) {
964 		mtx_unlock(&ioat->submit_lock);
965 		return (NULL);
966 	}
967 
968 	ioat_get(ioat);
969 	if (ioat->quiescing) {
970 		if ((flags & M_NOWAIT) != 0) {
971 			ioat_put(ioat);
972 			mtx_unlock(&ioat->submit_lock);
973 			return (NULL);
974 		}
975 
976 		while (ioat->quiescing && !ioat->destroying)
977 			msleep(&ioat->quiescing, &ioat->submit_lock, 0, "getdma", 0);
978 
979 		if (ioat->destroying) {
980 			ioat_put(ioat);
981 			mtx_unlock(&ioat->submit_lock);
982 			return (NULL);
983 		}
984 	}
985 	mtx_unlock(&ioat->submit_lock);
986 	return (&ioat->dmaengine);
987 }
988 
989 void
990 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
991 {
992 	struct ioat_softc *ioat;
993 
994 	ioat = to_ioat_softc(dmaengine);
995 	mtx_lock(&ioat->submit_lock);
996 	ioat_put(ioat);
997 	mtx_unlock(&ioat->submit_lock);
998 }
999 
1000 int
1001 ioat_get_hwversion(bus_dmaengine_t dmaengine)
1002 {
1003 	struct ioat_softc *ioat;
1004 
1005 	ioat = to_ioat_softc(dmaengine);
1006 	return (ioat->version);
1007 }
1008 
1009 size_t
1010 ioat_get_max_io_size(bus_dmaengine_t dmaengine)
1011 {
1012 	struct ioat_softc *ioat;
1013 
1014 	ioat = to_ioat_softc(dmaengine);
1015 	return (ioat->max_xfer_size);
1016 }
1017 
1018 uint32_t
1019 ioat_get_capabilities(bus_dmaengine_t dmaengine)
1020 {
1021 	struct ioat_softc *ioat;
1022 
1023 	ioat = to_ioat_softc(dmaengine);
1024 	return (ioat->capabilities);
1025 }
1026 
1027 int
1028 ioat_get_domain(bus_dmaengine_t dmaengine, int *domain)
1029 {
1030 	struct ioat_softc *ioat;
1031 
1032 	ioat = to_ioat_softc(dmaengine);
1033 	return (bus_get_domain(ioat->device, domain));
1034 }
1035 
1036 int
1037 ioat_set_interrupt_coalesce(bus_dmaengine_t dmaengine, uint16_t delay)
1038 {
1039 	struct ioat_softc *ioat;
1040 
1041 	ioat = to_ioat_softc(dmaengine);
1042 	if (!ioat->intrdelay_supported)
1043 		return (ENODEV);
1044 	if (delay > ioat->intrdelay_max)
1045 		return (ERANGE);
1046 
1047 	ioat_write_2(ioat, IOAT_INTRDELAY_OFFSET, delay);
1048 	ioat->cached_intrdelay =
1049 	    ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) & IOAT_INTRDELAY_US_MASK;
1050 	return (0);
1051 }
1052 
1053 uint16_t
1054 ioat_get_max_coalesce_period(bus_dmaengine_t dmaengine)
1055 {
1056 	struct ioat_softc *ioat;
1057 
1058 	ioat = to_ioat_softc(dmaengine);
1059 	return (ioat->intrdelay_max);
1060 }
1061 
1062 void
1063 ioat_acquire(bus_dmaengine_t dmaengine)
1064 {
1065 	struct ioat_softc *ioat;
1066 
1067 	ioat = to_ioat_softc(dmaengine);
1068 	mtx_lock(&ioat->submit_lock);
1069 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1070 	ioat->acq_head = ioat->head;
1071 }
1072 
1073 int
1074 ioat_acquire_reserve(bus_dmaengine_t dmaengine, unsigned n, int mflags)
1075 {
1076 	struct ioat_softc *ioat;
1077 	int error;
1078 
1079 	ioat = to_ioat_softc(dmaengine);
1080 	ioat_acquire(dmaengine);
1081 
1082 	error = ioat_reserve_space(ioat, n, mflags);
1083 	if (error != 0)
1084 		ioat_release(dmaengine);
1085 	return (error);
1086 }
1087 
1088 void
1089 ioat_release(bus_dmaengine_t dmaengine)
1090 {
1091 	struct ioat_softc *ioat;
1092 
1093 	ioat = to_ioat_softc(dmaengine);
1094 	CTR3(KTR_IOAT, "%s channel=%u dispatch1 head=%u", __func__,
1095 	    ioat->chan_idx, ioat->head);
1096 	KFAIL_POINT_CODE(DEBUG_FP, ioat_release, /* do nothing */);
1097 	CTR3(KTR_IOAT, "%s channel=%u dispatch2 head=%u", __func__,
1098 	    ioat->chan_idx, ioat->head);
1099 
1100 	if (ioat->acq_head != ioat->head) {
1101 		ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET,
1102 		    (uint16_t)ioat->head);
1103 
1104 		if (!callout_pending(&ioat->poll_timer)) {
1105 			callout_reset_on(&ioat->poll_timer, 1,
1106 			    ioat_poll_timer_callback, ioat, ioat->cpu);
1107 		}
1108 	}
1109 	mtx_unlock(&ioat->submit_lock);
1110 }
1111 
1112 static struct ioat_descriptor *
1113 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
1114     uint32_t size, uint64_t src, uint64_t dst,
1115     bus_dmaengine_callback_t callback_fn, void *callback_arg,
1116     uint32_t flags)
1117 {
1118 	struct ioat_generic_hw_descriptor *hw_desc;
1119 	struct ioat_descriptor *desc;
1120 	bus_dma_segment_t seg;
1121 	int mflags, nseg, error;
1122 
1123 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1124 
1125 	KASSERT((flags & ~_DMA_GENERIC_FLAGS) == 0,
1126 	    ("Unrecognized flag(s): %#x", flags & ~_DMA_GENERIC_FLAGS));
1127 	KASSERT(size <= ioat->max_xfer_size, ("%s: size too big (%u > %u)",
1128 	    __func__, (unsigned)size, ioat->max_xfer_size));
1129 
1130 	if ((flags & DMA_NO_WAIT) != 0)
1131 		mflags = M_NOWAIT;
1132 	else
1133 		mflags = M_WAITOK;
1134 
1135 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
1136 		return (NULL);
1137 
1138 	desc = ioat_get_ring_entry(ioat, ioat->head);
1139 	hw_desc = &ioat_get_descriptor(ioat, ioat->head)->generic;
1140 
1141 	hw_desc->u.control_raw = 0;
1142 	hw_desc->u.control_generic.op = op;
1143 	hw_desc->u.control_generic.completion_update = 1;
1144 
1145 	if ((flags & DMA_INT_EN) != 0)
1146 		hw_desc->u.control_generic.int_enable = 1;
1147 	if ((flags & DMA_FENCE) != 0)
1148 		hw_desc->u.control_generic.fence = 1;
1149 
1150 	hw_desc->size = size;
1151 
1152 	if (src != 0) {
1153 		nseg = -1;
1154 		error = _bus_dmamap_load_phys(ioat->data_tag, desc->src_dmamap,
1155 		    src, size, 0, &seg, &nseg);
1156 		if (error != 0) {
1157 			ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1158 			    " failed %d\n", __func__, error);
1159 			return (NULL);
1160 		}
1161 		hw_desc->src_addr = seg.ds_addr;
1162 	}
1163 
1164 	if (dst != 0) {
1165 		nseg = -1;
1166 		error = _bus_dmamap_load_phys(ioat->data_tag, desc->dst_dmamap,
1167 		    dst, size, 0, &seg, &nseg);
1168 		if (error != 0) {
1169 			ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1170 			    " failed %d\n", __func__, error);
1171 			return (NULL);
1172 		}
1173 		hw_desc->dest_addr = seg.ds_addr;
1174 	}
1175 
1176 	desc->bus_dmadesc.callback_fn = callback_fn;
1177 	desc->bus_dmadesc.callback_arg = callback_arg;
1178 	return (desc);
1179 }
1180 
1181 struct bus_dmadesc *
1182 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
1183     void *callback_arg, uint32_t flags)
1184 {
1185 	struct ioat_dma_hw_descriptor *hw_desc;
1186 	struct ioat_descriptor *desc;
1187 	struct ioat_softc *ioat;
1188 
1189 	ioat = to_ioat_softc(dmaengine);
1190 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1191 
1192 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
1193 	    callback_arg, flags);
1194 	if (desc == NULL)
1195 		return (NULL);
1196 
1197 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1198 	hw_desc->u.control.null = 1;
1199 	ioat_submit_single(ioat);
1200 	return (&desc->bus_dmadesc);
1201 }
1202 
1203 struct bus_dmadesc *
1204 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
1205     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
1206     void *callback_arg, uint32_t flags)
1207 {
1208 	struct ioat_dma_hw_descriptor *hw_desc;
1209 	struct ioat_descriptor *desc;
1210 	struct ioat_softc *ioat;
1211 
1212 	ioat = to_ioat_softc(dmaengine);
1213 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
1214 	    callback_arg, flags);
1215 	if (desc == NULL)
1216 		return (NULL);
1217 
1218 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1219 	if (g_ioat_debug_level >= 3)
1220 		dump_descriptor(hw_desc);
1221 
1222 	ioat_submit_single(ioat);
1223 	CTR6(KTR_IOAT, "%s channel=%u desc=%p dest=%lx src=%lx len=%lx",
1224 	    __func__, ioat->chan_idx, &desc->bus_dmadesc, dst, src, len);
1225 	return (&desc->bus_dmadesc);
1226 }
1227 
1228 struct bus_dmadesc *
1229 ioat_copy_8k_aligned(bus_dmaengine_t dmaengine, bus_addr_t dst1,
1230     bus_addr_t dst2, bus_addr_t src1, bus_addr_t src2,
1231     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1232 {
1233 	struct ioat_dma_hw_descriptor *hw_desc;
1234 	struct ioat_descriptor *desc;
1235 	struct ioat_softc *ioat;
1236 	bus_size_t src1_len, dst1_len;
1237 	bus_dma_segment_t seg;
1238 	int nseg, error;
1239 
1240 	ioat = to_ioat_softc(dmaengine);
1241 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1242 
1243 	KASSERT(((src1 | src2 | dst1 | dst2) & PAGE_MASK) == 0,
1244 	    ("%s: addresses are not page-aligned", __func__));
1245 
1246 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 2 * PAGE_SIZE, 0, 0,
1247 	    callback_fn, callback_arg, flags);
1248 	if (desc == NULL)
1249 		return (NULL);
1250 
1251 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1252 
1253 	src1_len = (src2 != src1 + PAGE_SIZE) ? PAGE_SIZE : 2 * PAGE_SIZE;
1254 	nseg = -1;
1255 	error = _bus_dmamap_load_phys(ioat->data_tag,
1256 	    desc->src_dmamap, src1, src1_len, 0, &seg, &nseg);
1257 	if (error != 0) {
1258 		ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1259 		    " failed %d\n", __func__, error);
1260 		return (NULL);
1261 	}
1262 	hw_desc->src_addr = seg.ds_addr;
1263 	if (src1_len != 2 * PAGE_SIZE) {
1264 		hw_desc->u.control.src_page_break = 1;
1265 		nseg = -1;
1266 		error = _bus_dmamap_load_phys(ioat->data_tag,
1267 		    desc->src2_dmamap, src2, PAGE_SIZE, 0, &seg, &nseg);
1268 		if (error != 0) {
1269 			ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1270 			    " failed %d\n", __func__, error);
1271 			return (NULL);
1272 		}
1273 		hw_desc->next_src_addr = seg.ds_addr;
1274 	}
1275 
1276 	dst1_len = (dst2 != dst1 + PAGE_SIZE) ? PAGE_SIZE : 2 * PAGE_SIZE;
1277 	nseg = -1;
1278 	error = _bus_dmamap_load_phys(ioat->data_tag,
1279 	    desc->dst_dmamap, dst1, dst1_len, 0, &seg, &nseg);
1280 	if (error != 0) {
1281 		ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1282 		    " failed %d\n", __func__, error);
1283 		return (NULL);
1284 	}
1285 	hw_desc->dest_addr = seg.ds_addr;
1286 	if (dst1_len != 2 * PAGE_SIZE) {
1287 		hw_desc->u.control.dest_page_break = 1;
1288 		nseg = -1;
1289 		error = _bus_dmamap_load_phys(ioat->data_tag,
1290 		    desc->dst2_dmamap, dst2, PAGE_SIZE, 0, &seg, &nseg);
1291 		if (error != 0) {
1292 			ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1293 			    " failed %d\n", __func__, error);
1294 			return (NULL);
1295 		}
1296 		hw_desc->next_dest_addr = seg.ds_addr;
1297 	}
1298 
1299 	if (g_ioat_debug_level >= 3)
1300 		dump_descriptor(hw_desc);
1301 
1302 	ioat_submit_single(ioat);
1303 	return (&desc->bus_dmadesc);
1304 }
1305 
1306 struct bus_dmadesc *
1307 ioat_copy_crc(bus_dmaengine_t dmaengine, bus_addr_t dst, bus_addr_t src,
1308     bus_size_t len, uint32_t *initialseed, bus_addr_t crcptr,
1309     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1310 {
1311 	struct ioat_crc32_hw_descriptor *hw_desc;
1312 	struct ioat_descriptor *desc;
1313 	struct ioat_softc *ioat;
1314 	uint32_t teststore;
1315 	uint8_t op;
1316 	bus_dma_segment_t seg;
1317 	int nseg, error;
1318 
1319 	ioat = to_ioat_softc(dmaengine);
1320 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1321 
1322 	KASSERT((ioat->capabilities & IOAT_DMACAP_MOVECRC) != 0,
1323 	    ("%s: device lacks MOVECRC capability", __func__));
1324 	teststore = (flags & _DMA_CRC_TESTSTORE);
1325 	KASSERT(teststore != _DMA_CRC_TESTSTORE,
1326 	    ("%s: TEST and STORE invalid", __func__));
1327 	KASSERT(teststore != 0 || (flags & DMA_CRC_INLINE) == 0,
1328 	    ("%s: INLINE invalid without TEST or STORE", __func__));
1329 
1330 	switch (teststore) {
1331 	case DMA_CRC_STORE:
1332 		op = IOAT_OP_MOVECRC_STORE;
1333 		break;
1334 	case DMA_CRC_TEST:
1335 		op = IOAT_OP_MOVECRC_TEST;
1336 		break;
1337 	default:
1338 		KASSERT(teststore == 0, ("bogus"));
1339 		op = IOAT_OP_MOVECRC;
1340 		break;
1341 	}
1342 
1343 	desc = ioat_op_generic(ioat, op, len, src, dst, callback_fn,
1344 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1345 	if (desc == NULL)
1346 		return (NULL);
1347 
1348 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1349 
1350 	if ((flags & DMA_CRC_INLINE) == 0) {
1351 		nseg = -1;
1352 		error = _bus_dmamap_load_phys(ioat->data_tag,
1353 		    desc->dst2_dmamap, crcptr, sizeof(uint32_t), 0,
1354 		    &seg, &nseg);
1355 		if (error != 0) {
1356 			ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1357 			    " failed %d\n", __func__, error);
1358 			return (NULL);
1359 		}
1360 		hw_desc->crc_address = seg.ds_addr;
1361 	} else
1362 		hw_desc->u.control.crc_location = 1;
1363 
1364 	if (initialseed != NULL) {
1365 		hw_desc->u.control.use_seed = 1;
1366 		hw_desc->seed = *initialseed;
1367 	}
1368 
1369 	if (g_ioat_debug_level >= 3)
1370 		dump_descriptor(hw_desc);
1371 
1372 	ioat_submit_single(ioat);
1373 	return (&desc->bus_dmadesc);
1374 }
1375 
1376 struct bus_dmadesc *
1377 ioat_crc(bus_dmaengine_t dmaengine, bus_addr_t src, bus_size_t len,
1378     uint32_t *initialseed, bus_addr_t crcptr,
1379     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1380 {
1381 	struct ioat_crc32_hw_descriptor *hw_desc;
1382 	struct ioat_descriptor *desc;
1383 	struct ioat_softc *ioat;
1384 	uint32_t teststore;
1385 	uint8_t op;
1386 	bus_dma_segment_t seg;
1387 	int nseg, error;
1388 
1389 	ioat = to_ioat_softc(dmaengine);
1390 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1391 
1392 	KASSERT((ioat->capabilities & IOAT_DMACAP_CRC) != 0,
1393 	    ("%s: device lacks CRC capability", __func__));
1394 	teststore = (flags & _DMA_CRC_TESTSTORE);
1395 	KASSERT(teststore != _DMA_CRC_TESTSTORE,
1396 	    ("%s: TEST and STORE invalid", __func__));
1397 	KASSERT(teststore != 0 || (flags & DMA_CRC_INLINE) == 0,
1398 	    ("%s: INLINE invalid without TEST or STORE", __func__));
1399 
1400 	switch (teststore) {
1401 	case DMA_CRC_STORE:
1402 		op = IOAT_OP_CRC_STORE;
1403 		break;
1404 	case DMA_CRC_TEST:
1405 		op = IOAT_OP_CRC_TEST;
1406 		break;
1407 	default:
1408 		KASSERT(teststore == 0, ("bogus"));
1409 		op = IOAT_OP_CRC;
1410 		break;
1411 	}
1412 
1413 	desc = ioat_op_generic(ioat, op, len, src, 0, callback_fn,
1414 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1415 	if (desc == NULL)
1416 		return (NULL);
1417 
1418 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1419 
1420 	if ((flags & DMA_CRC_INLINE) == 0) {
1421 		nseg = -1;
1422 		error = _bus_dmamap_load_phys(ioat->data_tag,
1423 		    desc->dst2_dmamap, crcptr, sizeof(uint32_t), 0,
1424 		    &seg, &nseg);
1425 		if (error != 0) {
1426 			ioat_log_message(0, "%s: _bus_dmamap_load_phys"
1427 			    " failed %d\n", __func__, error);
1428 			return (NULL);
1429 		}
1430 		hw_desc->crc_address = seg.ds_addr;
1431 	} else
1432 		hw_desc->u.control.crc_location = 1;
1433 
1434 	if (initialseed != NULL) {
1435 		hw_desc->u.control.use_seed = 1;
1436 		hw_desc->seed = *initialseed;
1437 	}
1438 
1439 	if (g_ioat_debug_level >= 3)
1440 		dump_descriptor(hw_desc);
1441 
1442 	ioat_submit_single(ioat);
1443 	return (&desc->bus_dmadesc);
1444 }
1445 
1446 struct bus_dmadesc *
1447 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
1448     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
1449     uint32_t flags)
1450 {
1451 	struct ioat_fill_hw_descriptor *hw_desc;
1452 	struct ioat_descriptor *desc;
1453 	struct ioat_softc *ioat;
1454 
1455 	ioat = to_ioat_softc(dmaengine);
1456 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1457 
1458 	KASSERT((ioat->capabilities & IOAT_DMACAP_BFILL) != 0,
1459 	    ("%s: device lacks BFILL capability", __func__));
1460 
1461 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, 0, dst,
1462 	    callback_fn, callback_arg, flags);
1463 	if (desc == NULL)
1464 		return (NULL);
1465 
1466 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->fill;
1467 	hw_desc->src_data = fillpattern;
1468 	if (g_ioat_debug_level >= 3)
1469 		dump_descriptor(hw_desc);
1470 
1471 	ioat_submit_single(ioat);
1472 	return (&desc->bus_dmadesc);
1473 }
1474 
1475 /*
1476  * Ring Management
1477  */
1478 static inline uint32_t
1479 ioat_get_active(struct ioat_softc *ioat)
1480 {
1481 
1482 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
1483 }
1484 
1485 static inline uint32_t
1486 ioat_get_ring_space(struct ioat_softc *ioat)
1487 {
1488 
1489 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
1490 }
1491 
1492 /*
1493  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
1494  * for 'num_descs'.
1495  *
1496  * If mflags contains M_WAITOK, blocks until enough space is available.
1497  *
1498  * Returns zero on success, or an errno on error.  If num_descs is beyond the
1499  * maximum ring size, returns EINVAl; if allocation would block and mflags
1500  * contains M_NOWAIT, returns EAGAIN.
1501  *
1502  * Must be called with the submit_lock held; returns with the lock held.  The
1503  * lock may be dropped to allocate the ring.
1504  *
1505  * (The submit_lock is needed to add any entries to the ring, so callers are
1506  * assured enough room is available.)
1507  */
1508 static int
1509 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
1510 {
1511 	boolean_t dug;
1512 	int error;
1513 
1514 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1515 	error = 0;
1516 	dug = FALSE;
1517 
1518 	if (num_descs < 1 || num_descs >= (1 << ioat->ring_size_order)) {
1519 		error = EINVAL;
1520 		goto out;
1521 	}
1522 
1523 	for (;;) {
1524 		if (ioat->quiescing) {
1525 			error = ENXIO;
1526 			goto out;
1527 		}
1528 
1529 		if (ioat_get_ring_space(ioat) >= num_descs)
1530 			goto out;
1531 
1532 		CTR3(KTR_IOAT, "%s channel=%u starved (%u)", __func__,
1533 		    ioat->chan_idx, num_descs);
1534 
1535 		if (!dug && !ioat->is_submitter_processing) {
1536 			ioat->is_submitter_processing = TRUE;
1537 			mtx_unlock(&ioat->submit_lock);
1538 
1539 			CTR2(KTR_IOAT, "%s channel=%u attempting to process events",
1540 			    __func__, ioat->chan_idx);
1541 			ioat_process_events(ioat, FALSE);
1542 
1543 			mtx_lock(&ioat->submit_lock);
1544 			dug = TRUE;
1545 			KASSERT(ioat->is_submitter_processing == TRUE,
1546 			    ("is_submitter_processing"));
1547 			ioat->is_submitter_processing = FALSE;
1548 			wakeup(&ioat->tail);
1549 			continue;
1550 		}
1551 
1552 		if ((mflags & M_WAITOK) == 0) {
1553 			error = EAGAIN;
1554 			break;
1555 		}
1556 		CTR2(KTR_IOAT, "%s channel=%u blocking on completions",
1557 		    __func__, ioat->chan_idx);
1558 		msleep(&ioat->tail, &ioat->submit_lock, 0,
1559 		    "ioat_full", 0);
1560 		continue;
1561 	}
1562 
1563 out:
1564 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1565 	KASSERT(!ioat->quiescing || error == ENXIO,
1566 	    ("reserved during quiesce"));
1567 	return (error);
1568 }
1569 
1570 static void
1571 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1572     struct ioat_descriptor *ring)
1573 {
1574 
1575 	free_domain(ring, M_IOAT);
1576 }
1577 
1578 static struct ioat_descriptor *
1579 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1580 {
1581 
1582 	return (&ioat->ring[index % (1 << ioat->ring_size_order)]);
1583 }
1584 
1585 static union ioat_hw_descriptor *
1586 ioat_get_descriptor(struct ioat_softc *ioat, uint32_t index)
1587 {
1588 
1589 	return (&ioat->hw_desc_ring[index % (1 << ioat->ring_size_order)]);
1590 }
1591 
1592 static void
1593 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1594 {
1595 	union ioat_hw_descriptor *desc;
1596 
1597 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1598 	    IOAT_CHANERR_STR);
1599 	if (chanerr == 0)
1600 		return;
1601 
1602 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1603 
1604 	desc = ioat_get_descriptor(ioat, ioat->tail + 0);
1605 	dump_descriptor(desc);
1606 
1607 	desc = ioat_get_descriptor(ioat, ioat->tail + 1);
1608 	dump_descriptor(desc);
1609 }
1610 
1611 static void
1612 ioat_poll_timer_callback(void *arg)
1613 {
1614 	struct ioat_softc *ioat;
1615 
1616 	ioat = arg;
1617 	CTR1(KTR_IOAT, "%s", __func__);
1618 
1619 	ioat_process_events(ioat, FALSE);
1620 
1621 	mtx_lock(&ioat->submit_lock);
1622 	if (ioat_get_active(ioat) > 0)
1623 		callout_schedule(&ioat->poll_timer, 1);
1624 	mtx_unlock(&ioat->submit_lock);
1625 }
1626 
1627 /*
1628  * Support Functions
1629  */
1630 static void
1631 ioat_submit_single(struct ioat_softc *ioat)
1632 {
1633 
1634 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1635 
1636 	ioat->head++;
1637 	CTR4(KTR_IOAT, "%s channel=%u head=%u tail=%u", __func__,
1638 	    ioat->chan_idx, ioat->head, ioat->tail);
1639 
1640 	ioat->stats.descriptors_submitted++;
1641 }
1642 
1643 static int
1644 ioat_reset_hw(struct ioat_softc *ioat)
1645 {
1646 	uint64_t status;
1647 	uint32_t chanerr;
1648 	unsigned timeout;
1649 	int error;
1650 
1651 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1652 
1653 	mtx_lock(&ioat->submit_lock);
1654 	while (ioat->resetting && !ioat->destroying)
1655 		msleep(&ioat->resetting, &ioat->submit_lock, 0, "IRH_drain", 0);
1656 	if (ioat->destroying) {
1657 		mtx_unlock(&ioat->submit_lock);
1658 		return (ENXIO);
1659 	}
1660 	ioat->resetting = TRUE;
1661 	ioat->quiescing = TRUE;
1662 	mtx_unlock(&ioat->submit_lock);
1663 	mtx_lock(&ioat->cleanup_lock);
1664 	while (ioat_get_active(ioat) > 0)
1665 		msleep(&ioat->tail, &ioat->cleanup_lock, 0, "ioat_drain", 1);
1666 
1667 	/*
1668 	 * Suspend ioat_process_events while the hardware and softc are in an
1669 	 * indeterminate state.
1670 	 */
1671 	ioat->resetting_cleanup = TRUE;
1672 	mtx_unlock(&ioat->cleanup_lock);
1673 
1674 	CTR2(KTR_IOAT, "%s channel=%u quiesced and drained", __func__,
1675 	    ioat->chan_idx);
1676 
1677 	status = ioat_get_chansts(ioat);
1678 	if (is_ioat_active(status) || is_ioat_idle(status))
1679 		ioat_suspend(ioat);
1680 
1681 	/* Wait at most 20 ms */
1682 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1683 	    timeout < 20; timeout++) {
1684 		DELAY(1000);
1685 		status = ioat_get_chansts(ioat);
1686 	}
1687 	if (timeout == 20) {
1688 		error = ETIMEDOUT;
1689 		goto out;
1690 	}
1691 
1692 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1693 
1694 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1695 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1696 
1697 	CTR2(KTR_IOAT, "%s channel=%u hardware suspended", __func__,
1698 	    ioat->chan_idx);
1699 
1700 	/*
1701 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1702 	 *  that can cause stability issues for IOAT v3.
1703 	 */
1704 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1705 	    4);
1706 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1707 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1708 
1709 	/*
1710 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1711 	 * Save/restore their contents manually.
1712 	 */
1713 	if (ioat_model_resets_msix(ioat)) {
1714 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1715 		pci_save_state(ioat->device);
1716 	}
1717 
1718 	ioat_reset(ioat);
1719 	CTR2(KTR_IOAT, "%s channel=%u hardware reset", __func__,
1720 	    ioat->chan_idx);
1721 
1722 	/* Wait at most 20 ms */
1723 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1724 		DELAY(1000);
1725 	if (timeout == 20) {
1726 		error = ETIMEDOUT;
1727 		goto out;
1728 	}
1729 
1730 	if (ioat_model_resets_msix(ioat)) {
1731 		ioat_log_message(1, "device resets registers; restored\n");
1732 		pci_restore_state(ioat->device);
1733 	}
1734 
1735 	/* Reset attempts to return the hardware to "halted." */
1736 	status = ioat_get_chansts(ioat);
1737 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1738 		/* So this really shouldn't happen... */
1739 		ioat_log_message(0, "Device is active after a reset?\n");
1740 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1741 		error = 0;
1742 		goto out;
1743 	}
1744 
1745 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1746 	if (chanerr != 0) {
1747 		mtx_lock(&ioat->cleanup_lock);
1748 		ioat_halted_debug(ioat, chanerr);
1749 		mtx_unlock(&ioat->cleanup_lock);
1750 		error = EIO;
1751 		goto out;
1752 	}
1753 
1754 	/*
1755 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1756 	 * device back to active.
1757 	 *
1758 	 * The internal ring counter resets to zero, so we have to start over
1759 	 * at zero as well.
1760 	 */
1761 	ioat->tail = ioat->head = 0;
1762 	*ioat->comp_update = ioat->last_seen =
1763 	    RING_PHYS_ADDR(ioat, ioat->tail - 1);
1764 
1765 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1766 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1767 	ioat_write_chainaddr(ioat, RING_PHYS_ADDR(ioat, 0));
1768 	error = 0;
1769 	CTR2(KTR_IOAT, "%s channel=%u configured channel", __func__,
1770 	    ioat->chan_idx);
1771 
1772 out:
1773 	/* Enqueues a null operation and ensures it completes. */
1774 	if (error == 0) {
1775 		error = ioat_start_channel(ioat);
1776 		CTR2(KTR_IOAT, "%s channel=%u started channel", __func__,
1777 		    ioat->chan_idx);
1778 	}
1779 
1780 	/*
1781 	 * Resume completions now that ring state is consistent.
1782 	 */
1783 	mtx_lock(&ioat->cleanup_lock);
1784 	ioat->resetting_cleanup = FALSE;
1785 	mtx_unlock(&ioat->cleanup_lock);
1786 
1787 	/* Unblock submission of new work */
1788 	mtx_lock(&ioat->submit_lock);
1789 	ioat->quiescing = FALSE;
1790 	wakeup(&ioat->quiescing);
1791 
1792 	ioat->resetting = FALSE;
1793 	wakeup(&ioat->resetting);
1794 
1795 	CTR2(KTR_IOAT, "%s channel=%u reset done", __func__, ioat->chan_idx);
1796 	mtx_unlock(&ioat->submit_lock);
1797 
1798 	return (error);
1799 }
1800 
1801 static int
1802 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1803 {
1804 	struct ioat_softc *ioat;
1805 	struct sbuf sb;
1806 	uint64_t status;
1807 	int error;
1808 
1809 	ioat = arg1;
1810 
1811 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1812 
1813 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1814 	switch (status) {
1815 	case IOAT_CHANSTS_ACTIVE:
1816 		sbuf_printf(&sb, "ACTIVE");
1817 		break;
1818 	case IOAT_CHANSTS_IDLE:
1819 		sbuf_printf(&sb, "IDLE");
1820 		break;
1821 	case IOAT_CHANSTS_SUSPENDED:
1822 		sbuf_printf(&sb, "SUSPENDED");
1823 		break;
1824 	case IOAT_CHANSTS_HALTED:
1825 		sbuf_printf(&sb, "HALTED");
1826 		break;
1827 	case IOAT_CHANSTS_ARMED:
1828 		sbuf_printf(&sb, "ARMED");
1829 		break;
1830 	default:
1831 		sbuf_printf(&sb, "UNKNOWN");
1832 		break;
1833 	}
1834 	error = sbuf_finish(&sb);
1835 	sbuf_delete(&sb);
1836 
1837 	if (error != 0 || req->newptr == NULL)
1838 		return (error);
1839 	return (EINVAL);
1840 }
1841 
1842 static int
1843 sysctl_handle_dpi(SYSCTL_HANDLER_ARGS)
1844 {
1845 	struct ioat_softc *ioat;
1846 	struct sbuf sb;
1847 #define	PRECISION	"1"
1848 	const uintmax_t factor = 10;
1849 	uintmax_t rate;
1850 	int error;
1851 
1852 	ioat = arg1;
1853 	sbuf_new_for_sysctl(&sb, NULL, 16, req);
1854 
1855 	if (ioat->stats.interrupts == 0) {
1856 		sbuf_printf(&sb, "NaN");
1857 		goto out;
1858 	}
1859 	rate = ioat->stats.descriptors_processed * factor /
1860 	    ioat->stats.interrupts;
1861 	sbuf_printf(&sb, "%ju.%." PRECISION "ju", rate / factor,
1862 	    rate % factor);
1863 #undef	PRECISION
1864 out:
1865 	error = sbuf_finish(&sb);
1866 	sbuf_delete(&sb);
1867 	if (error != 0 || req->newptr == NULL)
1868 		return (error);
1869 	return (EINVAL);
1870 }
1871 
1872 static int
1873 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
1874 {
1875 	struct ioat_softc *ioat;
1876 	int error, arg;
1877 
1878 	ioat = arg1;
1879 
1880 	arg = 0;
1881 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1882 	if (error != 0 || req->newptr == NULL)
1883 		return (error);
1884 
1885 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1886 	if (error != 0)
1887 		return (error);
1888 
1889 	if (arg != 0)
1890 		error = ioat_reset_hw(ioat);
1891 
1892 	return (error);
1893 }
1894 
1895 static void
1896 dump_descriptor(void *hw_desc)
1897 {
1898 	int i, j;
1899 
1900 	for (i = 0; i < 2; i++) {
1901 		for (j = 0; j < 8; j++)
1902 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
1903 		printf("\n");
1904 	}
1905 }
1906 
1907 static void
1908 ioat_setup_sysctl(device_t device)
1909 {
1910 	struct sysctl_oid_list *par, *statpar, *state, *hammer;
1911 	struct sysctl_ctx_list *ctx;
1912 	struct sysctl_oid *tree, *tmp;
1913 	struct ioat_softc *ioat;
1914 
1915 	ioat = DEVICE2SOFTC(device);
1916 	ctx = device_get_sysctl_ctx(device);
1917 	tree = device_get_sysctl_tree(device);
1918 	par = SYSCTL_CHILDREN(tree);
1919 
1920 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
1921 	    &ioat->version, 0, "HW version (0xMM form)");
1922 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
1923 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
1924 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "intrdelay_supported", CTLFLAG_RD,
1925 	    &ioat->intrdelay_supported, 0, "Is INTRDELAY supported");
1926 	SYSCTL_ADD_U16(ctx, par, OID_AUTO, "intrdelay_max", CTLFLAG_RD,
1927 	    &ioat->intrdelay_max, 0,
1928 	    "Maximum configurable INTRDELAY on this channel (microseconds)");
1929 
1930 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "state", CTLFLAG_RD, NULL,
1931 	    "IOAT channel internal state");
1932 	state = SYSCTL_CHILDREN(tmp);
1933 
1934 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "ring_size_order", CTLFLAG_RD,
1935 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
1936 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "head", CTLFLAG_RD, &ioat->head,
1937 	    0, "SW descriptor head pointer index");
1938 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail,
1939 	    0, "SW descriptor tail pointer index");
1940 
1941 	SYSCTL_ADD_UQUAD(ctx, state, OID_AUTO, "last_completion", CTLFLAG_RD,
1942 	    ioat->comp_update, "HW addr of last completion");
1943 
1944 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_submitter_processing",
1945 	    CTLFLAG_RD, &ioat->is_submitter_processing, 0,
1946 	    "submitter processing");
1947 
1948 	SYSCTL_ADD_PROC(ctx, state, OID_AUTO, "chansts",
1949 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
1950 	    "String of the channel status");
1951 
1952 	SYSCTL_ADD_U16(ctx, state, OID_AUTO, "intrdelay", CTLFLAG_RD,
1953 	    &ioat->cached_intrdelay, 0,
1954 	    "Current INTRDELAY on this channel (cached, microseconds)");
1955 
1956 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "hammer", CTLFLAG_RD, NULL,
1957 	    "Big hammers (mostly for testing)");
1958 	hammer = SYSCTL_CHILDREN(tmp);
1959 
1960 	SYSCTL_ADD_PROC(ctx, hammer, OID_AUTO, "force_hw_reset",
1961 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
1962 	    "Set to non-zero to reset the hardware");
1963 
1964 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "stats", CTLFLAG_RD, NULL,
1965 	    "IOAT channel statistics");
1966 	statpar = SYSCTL_CHILDREN(tmp);
1967 
1968 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "interrupts",
1969 	    CTLFLAG_RW | CTLFLAG_STATS, &ioat->stats.interrupts,
1970 	    "Number of interrupts processed on this channel");
1971 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "descriptors",
1972 	    CTLFLAG_RW | CTLFLAG_STATS, &ioat->stats.descriptors_processed,
1973 	    "Number of descriptors processed on this channel");
1974 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "submitted",
1975 	    CTLFLAG_RW | CTLFLAG_STATS, &ioat->stats.descriptors_submitted,
1976 	    "Number of descriptors submitted to this channel");
1977 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "errored",
1978 	    CTLFLAG_RW | CTLFLAG_STATS, &ioat->stats.descriptors_error,
1979 	    "Number of descriptors failed by channel errors");
1980 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "halts",
1981 	    CTLFLAG_RW | CTLFLAG_STATS, &ioat->stats.channel_halts, 0,
1982 	    "Number of times the channel has halted");
1983 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "last_halt_chanerr",
1984 	    CTLFLAG_RW | CTLFLAG_STATS, &ioat->stats.last_halt_chanerr, 0,
1985 	    "The raw CHANERR when the channel was last halted");
1986 
1987 	SYSCTL_ADD_PROC(ctx, statpar, OID_AUTO, "desc_per_interrupt",
1988 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_dpi, "A",
1989 	    "Descriptors per interrupt");
1990 }
1991 
1992 static void
1993 ioat_get(struct ioat_softc *ioat)
1994 {
1995 
1996 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1997 	KASSERT(ioat->refcnt < UINT32_MAX, ("refcnt overflow"));
1998 
1999 	ioat->refcnt++;
2000 }
2001 
2002 static void
2003 ioat_put(struct ioat_softc *ioat)
2004 {
2005 
2006 	mtx_assert(&ioat->submit_lock, MA_OWNED);
2007 	KASSERT(ioat->refcnt >= 1, ("refcnt error"));
2008 
2009 	if (--ioat->refcnt == 0)
2010 		wakeup(&ioat->refcnt);
2011 }
2012 
2013 static void
2014 ioat_drain_locked(struct ioat_softc *ioat)
2015 {
2016 
2017 	mtx_assert(&ioat->submit_lock, MA_OWNED);
2018 
2019 	while (ioat->refcnt > 0)
2020 		msleep(&ioat->refcnt, &ioat->submit_lock, 0, "ioat_drain", 0);
2021 }
2022 
2023 #ifdef DDB
2024 #define	_db_show_lock(lo)	LOCK_CLASS(lo)->lc_ddb_show(lo)
2025 #define	db_show_lock(lk)	_db_show_lock(&(lk)->lock_object)
2026 DB_SHOW_COMMAND(ioat, db_show_ioat)
2027 {
2028 	struct ioat_softc *sc;
2029 	unsigned idx;
2030 
2031 	if (!have_addr)
2032 		goto usage;
2033 	idx = (unsigned)addr;
2034 	if (idx >= ioat_channel_index)
2035 		goto usage;
2036 
2037 	sc = ioat_channel[idx];
2038 	db_printf("ioat softc at %p\n", sc);
2039 	if (sc == NULL)
2040 		return;
2041 
2042 	db_printf(" version: %d\n", sc->version);
2043 	db_printf(" chan_idx: %u\n", sc->chan_idx);
2044 	db_printf(" submit_lock: ");
2045 	db_show_lock(&sc->submit_lock);
2046 
2047 	db_printf(" capabilities: %b\n", (int)sc->capabilities,
2048 	    IOAT_DMACAP_STR);
2049 	db_printf(" cached_intrdelay: %u\n", sc->cached_intrdelay);
2050 	db_printf(" *comp_update: 0x%jx\n", (uintmax_t)*sc->comp_update);
2051 
2052 	db_printf(" poll_timer:\n");
2053 	db_printf("  c_time: %ju\n", (uintmax_t)sc->poll_timer.c_time);
2054 	db_printf("  c_arg: %p\n", sc->poll_timer.c_arg);
2055 	db_printf("  c_func: %p\n", sc->poll_timer.c_func);
2056 	db_printf("  c_lock: %p\n", sc->poll_timer.c_lock);
2057 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->poll_timer.c_flags);
2058 
2059 	db_printf(" quiescing: %d\n", (int)sc->quiescing);
2060 	db_printf(" destroying: %d\n", (int)sc->destroying);
2061 	db_printf(" is_submitter_processing: %d\n",
2062 	    (int)sc->is_submitter_processing);
2063 	db_printf(" intrdelay_supported: %d\n", (int)sc->intrdelay_supported);
2064 	db_printf(" resetting: %d\n", (int)sc->resetting);
2065 
2066 	db_printf(" head: %u\n", sc->head);
2067 	db_printf(" tail: %u\n", sc->tail);
2068 	db_printf(" ring_size_order: %u\n", sc->ring_size_order);
2069 	db_printf(" last_seen: 0x%lx\n", sc->last_seen);
2070 	db_printf(" ring: %p\n", sc->ring);
2071 	db_printf(" descriptors: %p\n", sc->hw_desc_ring);
2072 	db_printf(" descriptors (phys): 0x%jx\n",
2073 	    (uintmax_t)sc->hw_desc_bus_addr);
2074 
2075 	db_printf("  ring[%u] (tail):\n", sc->tail %
2076 	    (1 << sc->ring_size_order));
2077 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->tail)->id);
2078 	db_printf("   addr: 0x%lx\n",
2079 	    RING_PHYS_ADDR(sc, sc->tail));
2080 	db_printf("   next: 0x%lx\n",
2081 	     ioat_get_descriptor(sc, sc->tail)->generic.next);
2082 
2083 	db_printf("  ring[%u] (head - 1):\n", (sc->head - 1) %
2084 	    (1 << sc->ring_size_order));
2085 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head - 1)->id);
2086 	db_printf("   addr: 0x%lx\n",
2087 	    RING_PHYS_ADDR(sc, sc->head - 1));
2088 	db_printf("   next: 0x%lx\n",
2089 	     ioat_get_descriptor(sc, sc->head - 1)->generic.next);
2090 
2091 	db_printf("  ring[%u] (head):\n", (sc->head) %
2092 	    (1 << sc->ring_size_order));
2093 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head)->id);
2094 	db_printf("   addr: 0x%lx\n",
2095 	    RING_PHYS_ADDR(sc, sc->head));
2096 	db_printf("   next: 0x%lx\n",
2097 	     ioat_get_descriptor(sc, sc->head)->generic.next);
2098 
2099 	for (idx = 0; idx < (1 << sc->ring_size_order); idx++)
2100 		if ((*sc->comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK)
2101 		    == RING_PHYS_ADDR(sc, idx))
2102 			db_printf("  ring[%u] == hardware tail\n", idx);
2103 
2104 	db_printf(" cleanup_lock: ");
2105 	db_show_lock(&sc->cleanup_lock);
2106 
2107 	db_printf(" refcnt: %u\n", sc->refcnt);
2108 	db_printf(" stats:\n");
2109 	db_printf("  interrupts: %lu\n", sc->stats.interrupts);
2110 	db_printf("  descriptors_processed: %lu\n", sc->stats.descriptors_processed);
2111 	db_printf("  descriptors_error: %lu\n", sc->stats.descriptors_error);
2112 	db_printf("  descriptors_submitted: %lu\n", sc->stats.descriptors_submitted);
2113 
2114 	db_printf("  channel_halts: %u\n", sc->stats.channel_halts);
2115 	db_printf("  last_halt_chanerr: %u\n", sc->stats.last_halt_chanerr);
2116 
2117 	if (db_pager_quit)
2118 		return;
2119 
2120 	db_printf(" hw status:\n");
2121 	db_printf("  status: 0x%lx\n", ioat_get_chansts(sc));
2122 	db_printf("  chanctrl: 0x%x\n",
2123 	    (unsigned)ioat_read_2(sc, IOAT_CHANCTRL_OFFSET));
2124 	db_printf("  chancmd: 0x%x\n",
2125 	    (unsigned)ioat_read_1(sc, IOAT_CHANCMD_OFFSET));
2126 	db_printf("  dmacount: 0x%x\n",
2127 	    (unsigned)ioat_read_2(sc, IOAT_DMACOUNT_OFFSET));
2128 	db_printf("  chainaddr: 0x%lx\n",
2129 	    ioat_read_double_4(sc, IOAT_CHAINADDR_OFFSET_LOW));
2130 	db_printf("  chancmp: 0x%lx\n",
2131 	    ioat_read_double_4(sc, IOAT_CHANCMP_OFFSET_LOW));
2132 	db_printf("  chanerr: %b\n",
2133 	    (int)ioat_read_4(sc, IOAT_CHANERR_OFFSET), IOAT_CHANERR_STR);
2134 	return;
2135 usage:
2136 	db_printf("usage: show ioat <0-%u>\n", ioat_channel_index);
2137 	return;
2138 }
2139 #endif /* DDB */
2140