xref: /freebsd/sys/dev/ioat/ioat.c (revision 884d26c84cba3ffc3d4e626306098fcdfe6a0c2b)
1 /*-
2  * Copyright (C) 2012 Intel Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_ddb.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/conf.h>
36 #include <sys/ioccom.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/rman.h>
43 #include <sys/sbuf.h>
44 #include <sys/sysctl.h>
45 #include <sys/taskqueue.h>
46 #include <sys/time.h>
47 #include <dev/pci/pcireg.h>
48 #include <dev/pci/pcivar.h>
49 #include <machine/bus.h>
50 #include <machine/resource.h>
51 #include <machine/stdarg.h>
52 
53 #ifdef DDB
54 #include <ddb/ddb.h>
55 #endif
56 
57 #include "ioat.h"
58 #include "ioat_hw.h"
59 #include "ioat_internal.h"
60 
61 #ifndef	BUS_SPACE_MAXADDR_40BIT
62 #define	BUS_SPACE_MAXADDR_40BIT	0xFFFFFFFFFFULL
63 #endif
64 #define	IOAT_REFLK	(&ioat->submit_lock)
65 #define	IOAT_SHRINK_PERIOD	(10 * hz)
66 
67 static int ioat_probe(device_t device);
68 static int ioat_attach(device_t device);
69 static int ioat_detach(device_t device);
70 static int ioat_setup_intr(struct ioat_softc *ioat);
71 static int ioat_teardown_intr(struct ioat_softc *ioat);
72 static int ioat3_attach(device_t device);
73 static int ioat_start_channel(struct ioat_softc *ioat);
74 static int ioat_map_pci_bar(struct ioat_softc *ioat);
75 static void ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg,
76     int error);
77 static void ioat_interrupt_handler(void *arg);
78 static boolean_t ioat_model_resets_msix(struct ioat_softc *ioat);
79 static int chanerr_to_errno(uint32_t);
80 static void ioat_process_events(struct ioat_softc *ioat);
81 static inline uint32_t ioat_get_active(struct ioat_softc *ioat);
82 static inline uint32_t ioat_get_ring_space(struct ioat_softc *ioat);
83 static void ioat_free_ring(struct ioat_softc *, uint32_t size,
84     struct ioat_descriptor **);
85 static void ioat_free_ring_entry(struct ioat_softc *ioat,
86     struct ioat_descriptor *desc);
87 static struct ioat_descriptor *ioat_alloc_ring_entry(struct ioat_softc *,
88     int mflags);
89 static int ioat_reserve_space(struct ioat_softc *, uint32_t, int mflags);
90 static struct ioat_descriptor *ioat_get_ring_entry(struct ioat_softc *ioat,
91     uint32_t index);
92 static struct ioat_descriptor **ioat_prealloc_ring(struct ioat_softc *,
93     uint32_t size, boolean_t need_dscr, int mflags);
94 static int ring_grow(struct ioat_softc *, uint32_t oldorder,
95     struct ioat_descriptor **);
96 static int ring_shrink(struct ioat_softc *, uint32_t oldorder,
97     struct ioat_descriptor **);
98 static void ioat_halted_debug(struct ioat_softc *, uint32_t);
99 static void ioat_poll_timer_callback(void *arg);
100 static void ioat_shrink_timer_callback(void *arg);
101 static void dump_descriptor(void *hw_desc);
102 static void ioat_submit_single(struct ioat_softc *ioat);
103 static void ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg,
104     int error);
105 static int ioat_reset_hw(struct ioat_softc *ioat);
106 static void ioat_reset_hw_task(void *, int);
107 static void ioat_setup_sysctl(device_t device);
108 static int sysctl_handle_reset(SYSCTL_HANDLER_ARGS);
109 static inline struct ioat_softc *ioat_get(struct ioat_softc *,
110     enum ioat_ref_kind);
111 static inline void ioat_put(struct ioat_softc *, enum ioat_ref_kind);
112 static inline void _ioat_putn(struct ioat_softc *, uint32_t,
113     enum ioat_ref_kind, boolean_t);
114 static inline void ioat_putn(struct ioat_softc *, uint32_t,
115     enum ioat_ref_kind);
116 static inline void ioat_putn_locked(struct ioat_softc *, uint32_t,
117     enum ioat_ref_kind);
118 static void ioat_drain_locked(struct ioat_softc *);
119 
120 #define	ioat_log_message(v, ...) do {					\
121 	if ((v) <= g_ioat_debug_level) {				\
122 		device_printf(ioat->device, __VA_ARGS__);		\
123 	}								\
124 } while (0)
125 
126 MALLOC_DEFINE(M_IOAT, "ioat", "ioat driver memory allocations");
127 SYSCTL_NODE(_hw, OID_AUTO, ioat, CTLFLAG_RD, 0, "ioat node");
128 
129 static int g_force_legacy_interrupts;
130 SYSCTL_INT(_hw_ioat, OID_AUTO, force_legacy_interrupts, CTLFLAG_RDTUN,
131     &g_force_legacy_interrupts, 0, "Set to non-zero to force MSI-X disabled");
132 
133 int g_ioat_debug_level = 0;
134 SYSCTL_INT(_hw_ioat, OID_AUTO, debug_level, CTLFLAG_RWTUN, &g_ioat_debug_level,
135     0, "Set log level (0-3) for ioat(4). Higher is more verbose.");
136 
137 /*
138  * OS <-> Driver interface structures
139  */
140 static device_method_t ioat_pci_methods[] = {
141 	/* Device interface */
142 	DEVMETHOD(device_probe,     ioat_probe),
143 	DEVMETHOD(device_attach,    ioat_attach),
144 	DEVMETHOD(device_detach,    ioat_detach),
145 	DEVMETHOD_END
146 };
147 
148 static driver_t ioat_pci_driver = {
149 	"ioat",
150 	ioat_pci_methods,
151 	sizeof(struct ioat_softc),
152 };
153 
154 static devclass_t ioat_devclass;
155 DRIVER_MODULE(ioat, pci, ioat_pci_driver, ioat_devclass, 0, 0);
156 MODULE_VERSION(ioat, 1);
157 
158 /*
159  * Private data structures
160  */
161 static struct ioat_softc *ioat_channel[IOAT_MAX_CHANNELS];
162 static unsigned ioat_channel_index = 0;
163 SYSCTL_UINT(_hw_ioat, OID_AUTO, channels, CTLFLAG_RD, &ioat_channel_index, 0,
164     "Number of IOAT channels attached");
165 
166 static struct _pcsid
167 {
168 	u_int32_t   type;
169 	const char  *desc;
170 } pci_ids[] = {
171 	{ 0x34308086, "TBG IOAT Ch0" },
172 	{ 0x34318086, "TBG IOAT Ch1" },
173 	{ 0x34328086, "TBG IOAT Ch2" },
174 	{ 0x34338086, "TBG IOAT Ch3" },
175 	{ 0x34298086, "TBG IOAT Ch4" },
176 	{ 0x342a8086, "TBG IOAT Ch5" },
177 	{ 0x342b8086, "TBG IOAT Ch6" },
178 	{ 0x342c8086, "TBG IOAT Ch7" },
179 
180 	{ 0x37108086, "JSF IOAT Ch0" },
181 	{ 0x37118086, "JSF IOAT Ch1" },
182 	{ 0x37128086, "JSF IOAT Ch2" },
183 	{ 0x37138086, "JSF IOAT Ch3" },
184 	{ 0x37148086, "JSF IOAT Ch4" },
185 	{ 0x37158086, "JSF IOAT Ch5" },
186 	{ 0x37168086, "JSF IOAT Ch6" },
187 	{ 0x37178086, "JSF IOAT Ch7" },
188 	{ 0x37188086, "JSF IOAT Ch0 (RAID)" },
189 	{ 0x37198086, "JSF IOAT Ch1 (RAID)" },
190 
191 	{ 0x3c208086, "SNB IOAT Ch0" },
192 	{ 0x3c218086, "SNB IOAT Ch1" },
193 	{ 0x3c228086, "SNB IOAT Ch2" },
194 	{ 0x3c238086, "SNB IOAT Ch3" },
195 	{ 0x3c248086, "SNB IOAT Ch4" },
196 	{ 0x3c258086, "SNB IOAT Ch5" },
197 	{ 0x3c268086, "SNB IOAT Ch6" },
198 	{ 0x3c278086, "SNB IOAT Ch7" },
199 	{ 0x3c2e8086, "SNB IOAT Ch0 (RAID)" },
200 	{ 0x3c2f8086, "SNB IOAT Ch1 (RAID)" },
201 
202 	{ 0x0e208086, "IVB IOAT Ch0" },
203 	{ 0x0e218086, "IVB IOAT Ch1" },
204 	{ 0x0e228086, "IVB IOAT Ch2" },
205 	{ 0x0e238086, "IVB IOAT Ch3" },
206 	{ 0x0e248086, "IVB IOAT Ch4" },
207 	{ 0x0e258086, "IVB IOAT Ch5" },
208 	{ 0x0e268086, "IVB IOAT Ch6" },
209 	{ 0x0e278086, "IVB IOAT Ch7" },
210 	{ 0x0e2e8086, "IVB IOAT Ch0 (RAID)" },
211 	{ 0x0e2f8086, "IVB IOAT Ch1 (RAID)" },
212 
213 	{ 0x2f208086, "HSW IOAT Ch0" },
214 	{ 0x2f218086, "HSW IOAT Ch1" },
215 	{ 0x2f228086, "HSW IOAT Ch2" },
216 	{ 0x2f238086, "HSW IOAT Ch3" },
217 	{ 0x2f248086, "HSW IOAT Ch4" },
218 	{ 0x2f258086, "HSW IOAT Ch5" },
219 	{ 0x2f268086, "HSW IOAT Ch6" },
220 	{ 0x2f278086, "HSW IOAT Ch7" },
221 	{ 0x2f2e8086, "HSW IOAT Ch0 (RAID)" },
222 	{ 0x2f2f8086, "HSW IOAT Ch1 (RAID)" },
223 
224 	{ 0x0c508086, "BWD IOAT Ch0" },
225 	{ 0x0c518086, "BWD IOAT Ch1" },
226 	{ 0x0c528086, "BWD IOAT Ch2" },
227 	{ 0x0c538086, "BWD IOAT Ch3" },
228 
229 	{ 0x6f508086, "BDXDE IOAT Ch0" },
230 	{ 0x6f518086, "BDXDE IOAT Ch1" },
231 	{ 0x6f528086, "BDXDE IOAT Ch2" },
232 	{ 0x6f538086, "BDXDE IOAT Ch3" },
233 
234 	{ 0x6f208086, "BDX IOAT Ch0" },
235 	{ 0x6f218086, "BDX IOAT Ch1" },
236 	{ 0x6f228086, "BDX IOAT Ch2" },
237 	{ 0x6f238086, "BDX IOAT Ch3" },
238 	{ 0x6f248086, "BDX IOAT Ch4" },
239 	{ 0x6f258086, "BDX IOAT Ch5" },
240 	{ 0x6f268086, "BDX IOAT Ch6" },
241 	{ 0x6f278086, "BDX IOAT Ch7" },
242 	{ 0x6f2e8086, "BDX IOAT Ch0 (RAID)" },
243 	{ 0x6f2f8086, "BDX IOAT Ch1 (RAID)" },
244 
245 	{ 0x00000000, NULL           }
246 };
247 
248 /*
249  * OS <-> Driver linkage functions
250  */
251 static int
252 ioat_probe(device_t device)
253 {
254 	struct _pcsid *ep;
255 	u_int32_t type;
256 
257 	type = pci_get_devid(device);
258 	for (ep = pci_ids; ep->type; ep++) {
259 		if (ep->type == type) {
260 			device_set_desc(device, ep->desc);
261 			return (0);
262 		}
263 	}
264 	return (ENXIO);
265 }
266 
267 static int
268 ioat_attach(device_t device)
269 {
270 	struct ioat_softc *ioat;
271 	int error;
272 
273 	ioat = DEVICE2SOFTC(device);
274 	ioat->device = device;
275 
276 	error = ioat_map_pci_bar(ioat);
277 	if (error != 0)
278 		goto err;
279 
280 	ioat->version = ioat_read_cbver(ioat);
281 	if (ioat->version < IOAT_VER_3_0) {
282 		error = ENODEV;
283 		goto err;
284 	}
285 
286 	error = ioat3_attach(device);
287 	if (error != 0)
288 		goto err;
289 
290 	error = pci_enable_busmaster(device);
291 	if (error != 0)
292 		goto err;
293 
294 	error = ioat_setup_intr(ioat);
295 	if (error != 0)
296 		goto err;
297 
298 	error = ioat_reset_hw(ioat);
299 	if (error != 0)
300 		goto err;
301 
302 	ioat_process_events(ioat);
303 	ioat_setup_sysctl(device);
304 
305 	ioat->chan_idx = ioat_channel_index;
306 	ioat_channel[ioat_channel_index++] = ioat;
307 	ioat_test_attach();
308 
309 err:
310 	if (error != 0)
311 		ioat_detach(device);
312 	return (error);
313 }
314 
315 static int
316 ioat_detach(device_t device)
317 {
318 	struct ioat_softc *ioat;
319 
320 	ioat = DEVICE2SOFTC(device);
321 
322 	ioat_test_detach();
323 	taskqueue_drain(taskqueue_thread, &ioat->reset_task);
324 
325 	mtx_lock(IOAT_REFLK);
326 	ioat->quiescing = TRUE;
327 	ioat->destroying = TRUE;
328 	wakeup(&ioat->quiescing);
329 	wakeup(&ioat->resetting);
330 
331 	ioat_channel[ioat->chan_idx] = NULL;
332 
333 	ioat_drain_locked(ioat);
334 	mtx_unlock(IOAT_REFLK);
335 
336 	ioat_teardown_intr(ioat);
337 	callout_drain(&ioat->poll_timer);
338 	callout_drain(&ioat->shrink_timer);
339 
340 	pci_disable_busmaster(device);
341 
342 	if (ioat->pci_resource != NULL)
343 		bus_release_resource(device, SYS_RES_MEMORY,
344 		    ioat->pci_resource_id, ioat->pci_resource);
345 
346 	if (ioat->ring != NULL)
347 		ioat_free_ring(ioat, 1 << ioat->ring_size_order, ioat->ring);
348 
349 	if (ioat->comp_update != NULL) {
350 		bus_dmamap_unload(ioat->comp_update_tag, ioat->comp_update_map);
351 		bus_dmamem_free(ioat->comp_update_tag, ioat->comp_update,
352 		    ioat->comp_update_map);
353 		bus_dma_tag_destroy(ioat->comp_update_tag);
354 	}
355 
356 	bus_dma_tag_destroy(ioat->hw_desc_tag);
357 
358 	return (0);
359 }
360 
361 static int
362 ioat_teardown_intr(struct ioat_softc *ioat)
363 {
364 
365 	if (ioat->tag != NULL)
366 		bus_teardown_intr(ioat->device, ioat->res, ioat->tag);
367 
368 	if (ioat->res != NULL)
369 		bus_release_resource(ioat->device, SYS_RES_IRQ,
370 		    rman_get_rid(ioat->res), ioat->res);
371 
372 	pci_release_msi(ioat->device);
373 	return (0);
374 }
375 
376 static int
377 ioat_start_channel(struct ioat_softc *ioat)
378 {
379 	struct ioat_dma_hw_descriptor *hw_desc;
380 	struct ioat_descriptor *desc;
381 	struct bus_dmadesc *dmadesc;
382 	uint64_t status;
383 	uint32_t chanerr;
384 	int i;
385 
386 	ioat_acquire(&ioat->dmaengine);
387 
388 	/* Submit 'NULL' operation manually to avoid quiescing flag */
389 	desc = ioat_get_ring_entry(ioat, ioat->head);
390 	dmadesc = &desc->bus_dmadesc;
391 	hw_desc = desc->u.dma;
392 
393 	dmadesc->callback_fn = NULL;
394 	dmadesc->callback_arg = NULL;
395 
396 	hw_desc->u.control_raw = 0;
397 	hw_desc->u.control_generic.op = IOAT_OP_COPY;
398 	hw_desc->u.control_generic.completion_update = 1;
399 	hw_desc->size = 8;
400 	hw_desc->src_addr = 0;
401 	hw_desc->dest_addr = 0;
402 	hw_desc->u.control.null = 1;
403 
404 	ioat_submit_single(ioat);
405 	ioat_release(&ioat->dmaengine);
406 
407 	for (i = 0; i < 100; i++) {
408 		DELAY(1);
409 		status = ioat_get_chansts(ioat);
410 		if (is_ioat_idle(status))
411 			return (0);
412 	}
413 
414 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
415 	ioat_log_message(0, "could not start channel: "
416 	    "status = %#jx error = %b\n", (uintmax_t)status, (int)chanerr,
417 	    IOAT_CHANERR_STR);
418 	return (ENXIO);
419 }
420 
421 /*
422  * Initialize Hardware
423  */
424 static int
425 ioat3_attach(device_t device)
426 {
427 	struct ioat_softc *ioat;
428 	struct ioat_descriptor **ring;
429 	struct ioat_descriptor *next;
430 	struct ioat_dma_hw_descriptor *dma_hw_desc;
431 	int i, num_descriptors;
432 	int error;
433 	uint8_t xfercap;
434 
435 	error = 0;
436 	ioat = DEVICE2SOFTC(device);
437 	ioat->capabilities = ioat_read_dmacapability(ioat);
438 
439 	ioat_log_message(0, "Capabilities: %b\n", (int)ioat->capabilities,
440 	    IOAT_DMACAP_STR);
441 
442 	xfercap = ioat_read_xfercap(ioat);
443 	ioat->max_xfer_size = 1 << xfercap;
444 
445 	ioat->intrdelay_supported = (ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) &
446 	    IOAT_INTRDELAY_SUPPORTED) != 0;
447 	if (ioat->intrdelay_supported)
448 		ioat->intrdelay_max = IOAT_INTRDELAY_US_MASK;
449 
450 	/* TODO: need to check DCA here if we ever do XOR/PQ */
451 
452 	mtx_init(&ioat->submit_lock, "ioat_submit", NULL, MTX_DEF);
453 	mtx_init(&ioat->cleanup_lock, "ioat_cleanup", NULL, MTX_DEF);
454 	callout_init(&ioat->poll_timer, 1);
455 	callout_init(&ioat->shrink_timer, 1);
456 	TASK_INIT(&ioat->reset_task, 0, ioat_reset_hw_task, ioat);
457 
458 	/* Establish lock order for Witness */
459 	mtx_lock(&ioat->submit_lock);
460 	mtx_lock(&ioat->cleanup_lock);
461 	mtx_unlock(&ioat->cleanup_lock);
462 	mtx_unlock(&ioat->submit_lock);
463 
464 	ioat->is_resize_pending = FALSE;
465 	ioat->is_submitter_processing = FALSE;
466 	ioat->is_completion_pending = FALSE;
467 	ioat->is_reset_pending = FALSE;
468 	ioat->is_channel_running = FALSE;
469 
470 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), sizeof(uint64_t), 0x0,
471 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
472 	    sizeof(uint64_t), 1, sizeof(uint64_t), 0, NULL, NULL,
473 	    &ioat->comp_update_tag);
474 
475 	error = bus_dmamem_alloc(ioat->comp_update_tag,
476 	    (void **)&ioat->comp_update, BUS_DMA_ZERO, &ioat->comp_update_map);
477 	if (ioat->comp_update == NULL)
478 		return (ENOMEM);
479 
480 	error = bus_dmamap_load(ioat->comp_update_tag, ioat->comp_update_map,
481 	    ioat->comp_update, sizeof(uint64_t), ioat_comp_update_map, ioat,
482 	    0);
483 	if (error != 0)
484 		return (error);
485 
486 	ioat->ring_size_order = IOAT_MIN_ORDER;
487 
488 	num_descriptors = 1 << ioat->ring_size_order;
489 
490 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), 0x40, 0x0,
491 	    BUS_SPACE_MAXADDR_40BIT, BUS_SPACE_MAXADDR, NULL, NULL,
492 	    sizeof(struct ioat_dma_hw_descriptor), 1,
493 	    sizeof(struct ioat_dma_hw_descriptor), 0, NULL, NULL,
494 	    &ioat->hw_desc_tag);
495 
496 	ioat->ring = malloc(num_descriptors * sizeof(*ring), M_IOAT,
497 	    M_ZERO | M_WAITOK);
498 
499 	ring = ioat->ring;
500 	for (i = 0; i < num_descriptors; i++) {
501 		ring[i] = ioat_alloc_ring_entry(ioat, M_WAITOK);
502 		if (ring[i] == NULL)
503 			return (ENOMEM);
504 
505 		ring[i]->id = i;
506 	}
507 
508 	for (i = 0; i < num_descriptors - 1; i++) {
509 		next = ring[i + 1];
510 		dma_hw_desc = ring[i]->u.dma;
511 
512 		dma_hw_desc->next = next->hw_desc_bus_addr;
513 	}
514 
515 	ring[i]->u.dma->next = ring[0]->hw_desc_bus_addr;
516 
517 	ioat->head = ioat->hw_head = 0;
518 	ioat->tail = 0;
519 	ioat->last_seen = 0;
520 	*ioat->comp_update = 0;
521 	return (0);
522 }
523 
524 static int
525 ioat_map_pci_bar(struct ioat_softc *ioat)
526 {
527 
528 	ioat->pci_resource_id = PCIR_BAR(0);
529 	ioat->pci_resource = bus_alloc_resource_any(ioat->device,
530 	    SYS_RES_MEMORY, &ioat->pci_resource_id, RF_ACTIVE);
531 
532 	if (ioat->pci_resource == NULL) {
533 		ioat_log_message(0, "unable to allocate pci resource\n");
534 		return (ENODEV);
535 	}
536 
537 	ioat->pci_bus_tag = rman_get_bustag(ioat->pci_resource);
538 	ioat->pci_bus_handle = rman_get_bushandle(ioat->pci_resource);
539 	return (0);
540 }
541 
542 static void
543 ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
544 {
545 	struct ioat_softc *ioat = arg;
546 
547 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
548 	ioat->comp_update_bus_addr = seg[0].ds_addr;
549 }
550 
551 static void
552 ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
553 {
554 	bus_addr_t *baddr;
555 
556 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
557 	baddr = arg;
558 	*baddr = segs->ds_addr;
559 }
560 
561 /*
562  * Interrupt setup and handlers
563  */
564 static int
565 ioat_setup_intr(struct ioat_softc *ioat)
566 {
567 	uint32_t num_vectors;
568 	int error;
569 	boolean_t use_msix;
570 	boolean_t force_legacy_interrupts;
571 
572 	use_msix = FALSE;
573 	force_legacy_interrupts = FALSE;
574 
575 	if (!g_force_legacy_interrupts && pci_msix_count(ioat->device) >= 1) {
576 		num_vectors = 1;
577 		pci_alloc_msix(ioat->device, &num_vectors);
578 		if (num_vectors == 1)
579 			use_msix = TRUE;
580 	}
581 
582 	if (use_msix) {
583 		ioat->rid = 1;
584 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
585 		    &ioat->rid, RF_ACTIVE);
586 	} else {
587 		ioat->rid = 0;
588 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
589 		    &ioat->rid, RF_SHAREABLE | RF_ACTIVE);
590 	}
591 	if (ioat->res == NULL) {
592 		ioat_log_message(0, "bus_alloc_resource failed\n");
593 		return (ENOMEM);
594 	}
595 
596 	ioat->tag = NULL;
597 	error = bus_setup_intr(ioat->device, ioat->res, INTR_MPSAFE |
598 	    INTR_TYPE_MISC, NULL, ioat_interrupt_handler, ioat, &ioat->tag);
599 	if (error != 0) {
600 		ioat_log_message(0, "bus_setup_intr failed\n");
601 		return (error);
602 	}
603 
604 	ioat_write_intrctrl(ioat, IOAT_INTRCTRL_MASTER_INT_EN);
605 	return (0);
606 }
607 
608 static boolean_t
609 ioat_model_resets_msix(struct ioat_softc *ioat)
610 {
611 	u_int32_t pciid;
612 
613 	pciid = pci_get_devid(ioat->device);
614 	switch (pciid) {
615 		/* BWD: */
616 	case 0x0c508086:
617 	case 0x0c518086:
618 	case 0x0c528086:
619 	case 0x0c538086:
620 		/* BDXDE: */
621 	case 0x6f508086:
622 	case 0x6f518086:
623 	case 0x6f528086:
624 	case 0x6f538086:
625 		return (TRUE);
626 	}
627 
628 	return (FALSE);
629 }
630 
631 static void
632 ioat_interrupt_handler(void *arg)
633 {
634 	struct ioat_softc *ioat = arg;
635 
636 	ioat->stats.interrupts++;
637 	ioat_process_events(ioat);
638 }
639 
640 static int
641 chanerr_to_errno(uint32_t chanerr)
642 {
643 
644 	if (chanerr == 0)
645 		return (0);
646 	if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
647 		return (EFAULT);
648 	if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
649 		return (EIO);
650 	/* This one is probably our fault: */
651 	if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
652 		return (EIO);
653 	return (EIO);
654 }
655 
656 static void
657 ioat_process_events(struct ioat_softc *ioat)
658 {
659 	struct ioat_descriptor *desc;
660 	struct bus_dmadesc *dmadesc;
661 	uint64_t comp_update, status;
662 	uint32_t completed, chanerr;
663 	boolean_t pending;
664 	int error;
665 
666 	CTR0(KTR_IOAT, __func__);
667 
668 	mtx_lock(&ioat->cleanup_lock);
669 
670 	/*
671 	 * Don't run while the hardware is being reset.  Reset is responsible
672 	 * for blocking new work and draining & completing existing work, so
673 	 * there is nothing to do until new work is queued after reset anyway.
674 	 */
675 	if (ioat->resetting_cleanup) {
676 		mtx_unlock(&ioat->cleanup_lock);
677 		return;
678 	}
679 
680 	completed = 0;
681 	comp_update = *ioat->comp_update;
682 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
683 
684 	if (status == ioat->last_seen) {
685 		/*
686 		 * If we landed in process_events and nothing has been
687 		 * completed, check for a timeout due to channel halt.
688 		 */
689 		comp_update = ioat_get_chansts(ioat);
690 		goto out;
691 	}
692 
693 	while (1) {
694 		desc = ioat_get_ring_entry(ioat, ioat->tail);
695 		dmadesc = &desc->bus_dmadesc;
696 		CTR3(KTR_IOAT, "completing desc %u ok  cb %p(%p)", ioat->tail,
697 		    dmadesc->callback_fn, dmadesc->callback_arg);
698 
699 		if (dmadesc->callback_fn != NULL)
700 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
701 
702 		completed++;
703 		ioat->tail++;
704 		if (desc->hw_desc_bus_addr == status)
705 			break;
706 
707 		KASSERT(ioat_get_active(ioat) > 0, ("overrunning ring t:%u "
708 		    "h:%u st:0x%016lx last_seen:%016lx completed:%u\n",
709 		    ioat->tail, ioat->head, comp_update, ioat->last_seen,
710 		    completed));
711 	}
712 
713 	ioat->last_seen = desc->hw_desc_bus_addr;
714 	ioat->stats.descriptors_processed += completed;
715 
716 out:
717 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
718 
719 	/* Perform a racy check first; only take the locks if it passes. */
720 	pending = (ioat_get_active(ioat) != 0);
721 	if (!pending && ioat->is_completion_pending) {
722 		mtx_unlock(&ioat->cleanup_lock);
723 		mtx_lock(&ioat->submit_lock);
724 		mtx_lock(&ioat->cleanup_lock);
725 
726 		pending = (ioat_get_active(ioat) != 0);
727 		if (!pending && ioat->is_completion_pending) {
728 			ioat->is_completion_pending = FALSE;
729 			callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
730 			    ioat_shrink_timer_callback, ioat);
731 			callout_stop(&ioat->poll_timer);
732 		}
733 		mtx_unlock(&ioat->submit_lock);
734 	}
735 	mtx_unlock(&ioat->cleanup_lock);
736 
737 	if (pending)
738 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
739 		    ioat);
740 
741 	if (completed != 0) {
742 		ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
743 		wakeup(&ioat->tail);
744 	}
745 
746 	if (!is_ioat_halted(comp_update) && !is_ioat_suspended(comp_update))
747 		return;
748 
749 	ioat->stats.channel_halts++;
750 
751 	/*
752 	 * Fatal programming error on this DMA channel.  Flush any outstanding
753 	 * work with error status and restart the engine.
754 	 */
755 	ioat_log_message(0, "Channel halted due to fatal programming error\n");
756 	mtx_lock(&ioat->submit_lock);
757 	mtx_lock(&ioat->cleanup_lock);
758 	ioat->quiescing = TRUE;
759 
760 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
761 	ioat_halted_debug(ioat, chanerr);
762 	ioat->stats.last_halt_chanerr = chanerr;
763 
764 	while (ioat_get_active(ioat) > 0) {
765 		desc = ioat_get_ring_entry(ioat, ioat->tail);
766 		dmadesc = &desc->bus_dmadesc;
767 		CTR3(KTR_IOAT, "completing desc %u err cb %p(%p)", ioat->tail,
768 		    dmadesc->callback_fn, dmadesc->callback_arg);
769 
770 		if (dmadesc->callback_fn != NULL)
771 			dmadesc->callback_fn(dmadesc->callback_arg,
772 			    chanerr_to_errno(chanerr));
773 
774 		ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
775 		ioat->tail++;
776 		ioat->stats.descriptors_processed++;
777 		ioat->stats.descriptors_error++;
778 	}
779 
780 	/* Clear error status */
781 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
782 
783 	mtx_unlock(&ioat->cleanup_lock);
784 	mtx_unlock(&ioat->submit_lock);
785 
786 	ioat_log_message(0, "Resetting channel to recover from error\n");
787 	error = taskqueue_enqueue(taskqueue_thread, &ioat->reset_task);
788 	KASSERT(error == 0,
789 	    ("%s: taskqueue_enqueue failed: %d", __func__, error));
790 }
791 
792 static void
793 ioat_reset_hw_task(void *ctx, int pending __unused)
794 {
795 	struct ioat_softc *ioat;
796 	int error;
797 
798 	ioat = ctx;
799 	ioat_log_message(1, "%s: Resetting channel\n", __func__);
800 
801 	error = ioat_reset_hw(ioat);
802 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
803 	(void)error;
804 }
805 
806 /*
807  * User API functions
808  */
809 unsigned
810 ioat_get_nchannels(void)
811 {
812 
813 	return (ioat_channel_index);
814 }
815 
816 bus_dmaengine_t
817 ioat_get_dmaengine(uint32_t index, int flags)
818 {
819 	struct ioat_softc *ioat;
820 
821 	KASSERT((flags & ~(M_NOWAIT | M_WAITOK)) == 0,
822 	    ("invalid flags: 0x%08x", flags));
823 	KASSERT((flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK),
824 	    ("invalid wait | nowait"));
825 
826 	if (index >= ioat_channel_index)
827 		return (NULL);
828 
829 	ioat = ioat_channel[index];
830 	if (ioat == NULL || ioat->destroying)
831 		return (NULL);
832 
833 	if (ioat->quiescing) {
834 		if ((flags & M_NOWAIT) != 0)
835 			return (NULL);
836 
837 		mtx_lock(IOAT_REFLK);
838 		while (ioat->quiescing && !ioat->destroying)
839 			msleep(&ioat->quiescing, IOAT_REFLK, 0, "getdma", 0);
840 		mtx_unlock(IOAT_REFLK);
841 
842 		if (ioat->destroying)
843 			return (NULL);
844 	}
845 
846 	/*
847 	 * There's a race here between the quiescing check and HW reset or
848 	 * module destroy.
849 	 */
850 	return (&ioat_get(ioat, IOAT_DMAENGINE_REF)->dmaengine);
851 }
852 
853 void
854 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
855 {
856 	struct ioat_softc *ioat;
857 
858 	ioat = to_ioat_softc(dmaengine);
859 	ioat_put(ioat, IOAT_DMAENGINE_REF);
860 }
861 
862 int
863 ioat_get_hwversion(bus_dmaengine_t dmaengine)
864 {
865 	struct ioat_softc *ioat;
866 
867 	ioat = to_ioat_softc(dmaengine);
868 	return (ioat->version);
869 }
870 
871 size_t
872 ioat_get_max_io_size(bus_dmaengine_t dmaengine)
873 {
874 	struct ioat_softc *ioat;
875 
876 	ioat = to_ioat_softc(dmaengine);
877 	return (ioat->max_xfer_size);
878 }
879 
880 uint32_t
881 ioat_get_capabilities(bus_dmaengine_t dmaengine)
882 {
883 	struct ioat_softc *ioat;
884 
885 	ioat = to_ioat_softc(dmaengine);
886 	return (ioat->capabilities);
887 }
888 
889 int
890 ioat_set_interrupt_coalesce(bus_dmaengine_t dmaengine, uint16_t delay)
891 {
892 	struct ioat_softc *ioat;
893 
894 	ioat = to_ioat_softc(dmaengine);
895 	if (!ioat->intrdelay_supported)
896 		return (ENODEV);
897 	if (delay > ioat->intrdelay_max)
898 		return (ERANGE);
899 
900 	ioat_write_2(ioat, IOAT_INTRDELAY_OFFSET, delay);
901 	ioat->cached_intrdelay =
902 	    ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) & IOAT_INTRDELAY_US_MASK;
903 	return (0);
904 }
905 
906 uint16_t
907 ioat_get_max_coalesce_period(bus_dmaengine_t dmaengine)
908 {
909 	struct ioat_softc *ioat;
910 
911 	ioat = to_ioat_softc(dmaengine);
912 	return (ioat->intrdelay_max);
913 }
914 
915 void
916 ioat_acquire(bus_dmaengine_t dmaengine)
917 {
918 	struct ioat_softc *ioat;
919 
920 	ioat = to_ioat_softc(dmaengine);
921 	mtx_lock(&ioat->submit_lock);
922 	CTR0(KTR_IOAT, __func__);
923 }
924 
925 int
926 ioat_acquire_reserve(bus_dmaengine_t dmaengine, unsigned n, int mflags)
927 {
928 	struct ioat_softc *ioat;
929 	int error;
930 
931 	ioat = to_ioat_softc(dmaengine);
932 	ioat_acquire(dmaengine);
933 
934 	error = ioat_reserve_space(ioat, n, mflags);
935 	if (error != 0)
936 		ioat_release(dmaengine);
937 	return (error);
938 }
939 
940 void
941 ioat_release(bus_dmaengine_t dmaengine)
942 {
943 	struct ioat_softc *ioat;
944 
945 	ioat = to_ioat_softc(dmaengine);
946 	CTR0(KTR_IOAT, __func__);
947 	ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET, (uint16_t)ioat->hw_head);
948 	mtx_unlock(&ioat->submit_lock);
949 }
950 
951 static struct ioat_descriptor *
952 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
953     uint32_t size, uint64_t src, uint64_t dst,
954     bus_dmaengine_callback_t callback_fn, void *callback_arg,
955     uint32_t flags)
956 {
957 	struct ioat_generic_hw_descriptor *hw_desc;
958 	struct ioat_descriptor *desc;
959 	int mflags;
960 
961 	mtx_assert(&ioat->submit_lock, MA_OWNED);
962 
963 	KASSERT((flags & ~_DMA_GENERIC_FLAGS) == 0,
964 	    ("Unrecognized flag(s): %#x", flags & ~_DMA_GENERIC_FLAGS));
965 	if ((flags & DMA_NO_WAIT) != 0)
966 		mflags = M_NOWAIT;
967 	else
968 		mflags = M_WAITOK;
969 
970 	if (size > ioat->max_xfer_size) {
971 		ioat_log_message(0, "%s: max_xfer_size = %d, requested = %u\n",
972 		    __func__, ioat->max_xfer_size, (unsigned)size);
973 		return (NULL);
974 	}
975 
976 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
977 		return (NULL);
978 
979 	desc = ioat_get_ring_entry(ioat, ioat->head);
980 	hw_desc = desc->u.generic;
981 
982 	hw_desc->u.control_raw = 0;
983 	hw_desc->u.control_generic.op = op;
984 	hw_desc->u.control_generic.completion_update = 1;
985 
986 	if ((flags & DMA_INT_EN) != 0)
987 		hw_desc->u.control_generic.int_enable = 1;
988 	if ((flags & DMA_FENCE) != 0)
989 		hw_desc->u.control_generic.fence = 1;
990 
991 	hw_desc->size = size;
992 	hw_desc->src_addr = src;
993 	hw_desc->dest_addr = dst;
994 
995 	desc->bus_dmadesc.callback_fn = callback_fn;
996 	desc->bus_dmadesc.callback_arg = callback_arg;
997 	return (desc);
998 }
999 
1000 struct bus_dmadesc *
1001 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
1002     void *callback_arg, uint32_t flags)
1003 {
1004 	struct ioat_dma_hw_descriptor *hw_desc;
1005 	struct ioat_descriptor *desc;
1006 	struct ioat_softc *ioat;
1007 
1008 	CTR0(KTR_IOAT, __func__);
1009 	ioat = to_ioat_softc(dmaengine);
1010 
1011 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
1012 	    callback_arg, flags);
1013 	if (desc == NULL)
1014 		return (NULL);
1015 
1016 	hw_desc = desc->u.dma;
1017 	hw_desc->u.control.null = 1;
1018 	ioat_submit_single(ioat);
1019 	return (&desc->bus_dmadesc);
1020 }
1021 
1022 struct bus_dmadesc *
1023 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
1024     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
1025     void *callback_arg, uint32_t flags)
1026 {
1027 	struct ioat_dma_hw_descriptor *hw_desc;
1028 	struct ioat_descriptor *desc;
1029 	struct ioat_softc *ioat;
1030 
1031 	CTR0(KTR_IOAT, __func__);
1032 	ioat = to_ioat_softc(dmaengine);
1033 
1034 	if (((src | dst) & (0xffffull << 48)) != 0) {
1035 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1036 		    __func__);
1037 		return (NULL);
1038 	}
1039 
1040 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
1041 	    callback_arg, flags);
1042 	if (desc == NULL)
1043 		return (NULL);
1044 
1045 	hw_desc = desc->u.dma;
1046 	if (g_ioat_debug_level >= 3)
1047 		dump_descriptor(hw_desc);
1048 
1049 	ioat_submit_single(ioat);
1050 	return (&desc->bus_dmadesc);
1051 }
1052 
1053 struct bus_dmadesc *
1054 ioat_copy_8k_aligned(bus_dmaengine_t dmaengine, bus_addr_t dst1,
1055     bus_addr_t dst2, bus_addr_t src1, bus_addr_t src2,
1056     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1057 {
1058 	struct ioat_dma_hw_descriptor *hw_desc;
1059 	struct ioat_descriptor *desc;
1060 	struct ioat_softc *ioat;
1061 
1062 	CTR0(KTR_IOAT, __func__);
1063 	ioat = to_ioat_softc(dmaengine);
1064 
1065 	if (((src1 | src2 | dst1 | dst2) & (0xffffull << 48)) != 0) {
1066 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1067 		    __func__);
1068 		return (NULL);
1069 	}
1070 	if (((src1 | src2 | dst1 | dst2) & PAGE_MASK) != 0) {
1071 		ioat_log_message(0, "%s: Addresses must be page-aligned\n",
1072 		    __func__);
1073 		return (NULL);
1074 	}
1075 
1076 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 2 * PAGE_SIZE, src1, dst1,
1077 	    callback_fn, callback_arg, flags);
1078 	if (desc == NULL)
1079 		return (NULL);
1080 
1081 	hw_desc = desc->u.dma;
1082 	if (src2 != src1 + PAGE_SIZE) {
1083 		hw_desc->u.control.src_page_break = 1;
1084 		hw_desc->next_src_addr = src2;
1085 	}
1086 	if (dst2 != dst1 + PAGE_SIZE) {
1087 		hw_desc->u.control.dest_page_break = 1;
1088 		hw_desc->next_dest_addr = dst2;
1089 	}
1090 
1091 	if (g_ioat_debug_level >= 3)
1092 		dump_descriptor(hw_desc);
1093 
1094 	ioat_submit_single(ioat);
1095 	return (&desc->bus_dmadesc);
1096 }
1097 
1098 struct bus_dmadesc *
1099 ioat_copy_crc(bus_dmaengine_t dmaengine, bus_addr_t dst, bus_addr_t src,
1100     bus_size_t len, uint32_t *initialseed, bus_addr_t crcptr,
1101     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1102 {
1103 	struct ioat_crc32_hw_descriptor *hw_desc;
1104 	struct ioat_descriptor *desc;
1105 	struct ioat_softc *ioat;
1106 	uint32_t teststore;
1107 	uint8_t op;
1108 
1109 	CTR0(KTR_IOAT, __func__);
1110 	ioat = to_ioat_softc(dmaengine);
1111 
1112 	if ((ioat->capabilities & IOAT_DMACAP_MOVECRC) == 0) {
1113 		ioat_log_message(0, "%s: Device lacks MOVECRC capability\n",
1114 		    __func__);
1115 		return (NULL);
1116 	}
1117 	if (((src | dst) & (0xffffffull << 40)) != 0) {
1118 		ioat_log_message(0, "%s: High 24 bits of src/dst invalid\n",
1119 		    __func__);
1120 		return (NULL);
1121 	}
1122 	teststore = (flags & _DMA_CRC_TESTSTORE);
1123 	if (teststore == _DMA_CRC_TESTSTORE) {
1124 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1125 		return (NULL);
1126 	}
1127 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1128 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1129 		    __func__);
1130 		return (NULL);
1131 	}
1132 
1133 	switch (teststore) {
1134 	case DMA_CRC_STORE:
1135 		op = IOAT_OP_MOVECRC_STORE;
1136 		break;
1137 	case DMA_CRC_TEST:
1138 		op = IOAT_OP_MOVECRC_TEST;
1139 		break;
1140 	default:
1141 		KASSERT(teststore == 0, ("bogus"));
1142 		op = IOAT_OP_MOVECRC;
1143 		break;
1144 	}
1145 
1146 	if ((flags & DMA_CRC_INLINE) == 0 &&
1147 	    (crcptr & (0xffffffull << 40)) != 0) {
1148 		ioat_log_message(0,
1149 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1150 		return (NULL);
1151 	}
1152 
1153 	desc = ioat_op_generic(ioat, op, len, src, dst, callback_fn,
1154 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1155 	if (desc == NULL)
1156 		return (NULL);
1157 
1158 	hw_desc = desc->u.crc32;
1159 
1160 	if ((flags & DMA_CRC_INLINE) == 0)
1161 		hw_desc->crc_address = crcptr;
1162 	else
1163 		hw_desc->u.control.crc_location = 1;
1164 
1165 	if (initialseed != NULL) {
1166 		hw_desc->u.control.use_seed = 1;
1167 		hw_desc->seed = *initialseed;
1168 	}
1169 
1170 	if (g_ioat_debug_level >= 3)
1171 		dump_descriptor(hw_desc);
1172 
1173 	ioat_submit_single(ioat);
1174 	return (&desc->bus_dmadesc);
1175 }
1176 
1177 struct bus_dmadesc *
1178 ioat_crc(bus_dmaengine_t dmaengine, bus_addr_t src, bus_size_t len,
1179     uint32_t *initialseed, bus_addr_t crcptr,
1180     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1181 {
1182 	struct ioat_crc32_hw_descriptor *hw_desc;
1183 	struct ioat_descriptor *desc;
1184 	struct ioat_softc *ioat;
1185 	uint32_t teststore;
1186 	uint8_t op;
1187 
1188 	CTR0(KTR_IOAT, __func__);
1189 	ioat = to_ioat_softc(dmaengine);
1190 
1191 	if ((ioat->capabilities & IOAT_DMACAP_CRC) == 0) {
1192 		ioat_log_message(0, "%s: Device lacks CRC capability\n",
1193 		    __func__);
1194 		return (NULL);
1195 	}
1196 	if ((src & (0xffffffull << 40)) != 0) {
1197 		ioat_log_message(0, "%s: High 24 bits of src invalid\n",
1198 		    __func__);
1199 		return (NULL);
1200 	}
1201 	teststore = (flags & _DMA_CRC_TESTSTORE);
1202 	if (teststore == _DMA_CRC_TESTSTORE) {
1203 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1204 		return (NULL);
1205 	}
1206 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1207 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1208 		    __func__);
1209 		return (NULL);
1210 	}
1211 
1212 	switch (teststore) {
1213 	case DMA_CRC_STORE:
1214 		op = IOAT_OP_CRC_STORE;
1215 		break;
1216 	case DMA_CRC_TEST:
1217 		op = IOAT_OP_CRC_TEST;
1218 		break;
1219 	default:
1220 		KASSERT(teststore == 0, ("bogus"));
1221 		op = IOAT_OP_CRC;
1222 		break;
1223 	}
1224 
1225 	if ((flags & DMA_CRC_INLINE) == 0 &&
1226 	    (crcptr & (0xffffffull << 40)) != 0) {
1227 		ioat_log_message(0,
1228 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1229 		return (NULL);
1230 	}
1231 
1232 	desc = ioat_op_generic(ioat, op, len, src, 0, callback_fn,
1233 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1234 	if (desc == NULL)
1235 		return (NULL);
1236 
1237 	hw_desc = desc->u.crc32;
1238 
1239 	if ((flags & DMA_CRC_INLINE) == 0)
1240 		hw_desc->crc_address = crcptr;
1241 	else
1242 		hw_desc->u.control.crc_location = 1;
1243 
1244 	if (initialseed != NULL) {
1245 		hw_desc->u.control.use_seed = 1;
1246 		hw_desc->seed = *initialseed;
1247 	}
1248 
1249 	if (g_ioat_debug_level >= 3)
1250 		dump_descriptor(hw_desc);
1251 
1252 	ioat_submit_single(ioat);
1253 	return (&desc->bus_dmadesc);
1254 }
1255 
1256 struct bus_dmadesc *
1257 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
1258     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
1259     uint32_t flags)
1260 {
1261 	struct ioat_fill_hw_descriptor *hw_desc;
1262 	struct ioat_descriptor *desc;
1263 	struct ioat_softc *ioat;
1264 
1265 	CTR0(KTR_IOAT, __func__);
1266 	ioat = to_ioat_softc(dmaengine);
1267 
1268 	if ((ioat->capabilities & IOAT_DMACAP_BFILL) == 0) {
1269 		ioat_log_message(0, "%s: Device lacks BFILL capability\n",
1270 		    __func__);
1271 		return (NULL);
1272 	}
1273 
1274 	if ((dst & (0xffffull << 48)) != 0) {
1275 		ioat_log_message(0, "%s: High 16 bits of dst invalid\n",
1276 		    __func__);
1277 		return (NULL);
1278 	}
1279 
1280 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, fillpattern, dst,
1281 	    callback_fn, callback_arg, flags);
1282 	if (desc == NULL)
1283 		return (NULL);
1284 
1285 	hw_desc = desc->u.fill;
1286 	if (g_ioat_debug_level >= 3)
1287 		dump_descriptor(hw_desc);
1288 
1289 	ioat_submit_single(ioat);
1290 	return (&desc->bus_dmadesc);
1291 }
1292 
1293 /*
1294  * Ring Management
1295  */
1296 static inline uint32_t
1297 ioat_get_active(struct ioat_softc *ioat)
1298 {
1299 
1300 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
1301 }
1302 
1303 static inline uint32_t
1304 ioat_get_ring_space(struct ioat_softc *ioat)
1305 {
1306 
1307 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
1308 }
1309 
1310 static struct ioat_descriptor *
1311 ioat_alloc_ring_entry(struct ioat_softc *ioat, int mflags)
1312 {
1313 	struct ioat_generic_hw_descriptor *hw_desc;
1314 	struct ioat_descriptor *desc;
1315 	int error, busdmaflag;
1316 
1317 	error = ENOMEM;
1318 	hw_desc = NULL;
1319 
1320 	if ((mflags & M_WAITOK) != 0)
1321 		busdmaflag = BUS_DMA_WAITOK;
1322 	else
1323 		busdmaflag = BUS_DMA_NOWAIT;
1324 
1325 	desc = malloc(sizeof(*desc), M_IOAT, mflags);
1326 	if (desc == NULL)
1327 		goto out;
1328 
1329 	bus_dmamem_alloc(ioat->hw_desc_tag, (void **)&hw_desc,
1330 	    BUS_DMA_ZERO | busdmaflag, &ioat->hw_desc_map);
1331 	if (hw_desc == NULL)
1332 		goto out;
1333 
1334 	memset(&desc->bus_dmadesc, 0, sizeof(desc->bus_dmadesc));
1335 	desc->u.generic = hw_desc;
1336 
1337 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
1338 	    sizeof(*hw_desc), ioat_dmamap_cb, &desc->hw_desc_bus_addr,
1339 	    busdmaflag);
1340 	if (error)
1341 		goto out;
1342 
1343 out:
1344 	if (error) {
1345 		ioat_free_ring_entry(ioat, desc);
1346 		return (NULL);
1347 	}
1348 	return (desc);
1349 }
1350 
1351 static void
1352 ioat_free_ring_entry(struct ioat_softc *ioat, struct ioat_descriptor *desc)
1353 {
1354 
1355 	if (desc == NULL)
1356 		return;
1357 
1358 	if (desc->u.generic)
1359 		bus_dmamem_free(ioat->hw_desc_tag, desc->u.generic,
1360 		    ioat->hw_desc_map);
1361 	free(desc, M_IOAT);
1362 }
1363 
1364 /*
1365  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
1366  * for 'num_descs'.
1367  *
1368  * If mflags contains M_WAITOK, blocks until enough space is available.
1369  *
1370  * Returns zero on success, or an errno on error.  If num_descs is beyond the
1371  * maximum ring size, returns EINVAl; if allocation would block and mflags
1372  * contains M_NOWAIT, returns EAGAIN.
1373  *
1374  * Must be called with the submit_lock held; returns with the lock held.  The
1375  * lock may be dropped to allocate the ring.
1376  *
1377  * (The submit_lock is needed to add any entries to the ring, so callers are
1378  * assured enough room is available.)
1379  */
1380 static int
1381 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
1382 {
1383 	struct ioat_descriptor **new_ring;
1384 	uint32_t order;
1385 	boolean_t dug;
1386 	int error;
1387 
1388 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1389 	error = 0;
1390 	dug = FALSE;
1391 
1392 	if (num_descs < 1 || num_descs >= (1 << IOAT_MAX_ORDER)) {
1393 		error = EINVAL;
1394 		goto out;
1395 	}
1396 
1397 	for (;;) {
1398 		if (ioat->quiescing) {
1399 			error = ENXIO;
1400 			goto out;
1401 		}
1402 
1403 		if (ioat_get_ring_space(ioat) >= num_descs)
1404 			goto out;
1405 
1406 		if (!dug && !ioat->is_submitter_processing &&
1407 		    (1 << ioat->ring_size_order) > num_descs) {
1408 			ioat->is_submitter_processing = TRUE;
1409 			mtx_unlock(&ioat->submit_lock);
1410 
1411 			ioat_process_events(ioat);
1412 
1413 			mtx_lock(&ioat->submit_lock);
1414 			dug = TRUE;
1415 			KASSERT(ioat->is_submitter_processing == TRUE,
1416 			    ("is_submitter_processing"));
1417 			ioat->is_submitter_processing = FALSE;
1418 			wakeup(&ioat->tail);
1419 			continue;
1420 		}
1421 
1422 		order = ioat->ring_size_order;
1423 		if (ioat->is_resize_pending || order == IOAT_MAX_ORDER) {
1424 			if ((mflags & M_WAITOK) != 0) {
1425 				msleep(&ioat->tail, &ioat->submit_lock, 0,
1426 				    "ioat_rsz", 0);
1427 				continue;
1428 			}
1429 
1430 			error = EAGAIN;
1431 			break;
1432 		}
1433 
1434 		ioat->is_resize_pending = TRUE;
1435 		for (;;) {
1436 			mtx_unlock(&ioat->submit_lock);
1437 
1438 			new_ring = ioat_prealloc_ring(ioat, 1 << (order + 1),
1439 			    TRUE, mflags);
1440 
1441 			mtx_lock(&ioat->submit_lock);
1442 			KASSERT(ioat->ring_size_order == order,
1443 			    ("is_resize_pending should protect order"));
1444 
1445 			if (new_ring == NULL) {
1446 				KASSERT((mflags & M_WAITOK) == 0,
1447 				    ("allocation failed"));
1448 				error = EAGAIN;
1449 				break;
1450 			}
1451 
1452 			error = ring_grow(ioat, order, new_ring);
1453 			if (error == 0)
1454 				break;
1455 		}
1456 		ioat->is_resize_pending = FALSE;
1457 		wakeup(&ioat->tail);
1458 		if (error)
1459 			break;
1460 	}
1461 
1462 out:
1463 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1464 	KASSERT(!ioat->quiescing || error == ENXIO,
1465 	    ("reserved during quiesce"));
1466 	return (error);
1467 }
1468 
1469 static struct ioat_descriptor **
1470 ioat_prealloc_ring(struct ioat_softc *ioat, uint32_t size, boolean_t need_dscr,
1471     int mflags)
1472 {
1473 	struct ioat_descriptor **ring;
1474 	uint32_t i;
1475 	int error;
1476 
1477 	KASSERT(size > 0 && powerof2(size), ("bogus size"));
1478 
1479 	ring = malloc(size * sizeof(*ring), M_IOAT, M_ZERO | mflags);
1480 	if (ring == NULL)
1481 		return (NULL);
1482 
1483 	if (need_dscr) {
1484 		error = ENOMEM;
1485 		for (i = size / 2; i < size; i++) {
1486 			ring[i] = ioat_alloc_ring_entry(ioat, mflags);
1487 			if (ring[i] == NULL)
1488 				goto out;
1489 			ring[i]->id = i;
1490 		}
1491 	}
1492 	error = 0;
1493 
1494 out:
1495 	if (error != 0 && ring != NULL) {
1496 		ioat_free_ring(ioat, size, ring);
1497 		ring = NULL;
1498 	}
1499 	return (ring);
1500 }
1501 
1502 static void
1503 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1504     struct ioat_descriptor **ring)
1505 {
1506 	uint32_t i;
1507 
1508 	for (i = 0; i < size; i++) {
1509 		if (ring[i] != NULL)
1510 			ioat_free_ring_entry(ioat, ring[i]);
1511 	}
1512 	free(ring, M_IOAT);
1513 }
1514 
1515 static struct ioat_descriptor *
1516 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1517 {
1518 
1519 	return (ioat->ring[index % (1 << ioat->ring_size_order)]);
1520 }
1521 
1522 static int
1523 ring_grow(struct ioat_softc *ioat, uint32_t oldorder,
1524     struct ioat_descriptor **newring)
1525 {
1526 	struct ioat_descriptor *tmp, *next;
1527 	struct ioat_dma_hw_descriptor *hw;
1528 	uint32_t oldsize, newsize, head, tail, i, end;
1529 	int error;
1530 
1531 	CTR0(KTR_IOAT, __func__);
1532 
1533 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1534 
1535 	if (oldorder != ioat->ring_size_order || oldorder >= IOAT_MAX_ORDER) {
1536 		error = EINVAL;
1537 		goto out;
1538 	}
1539 
1540 	oldsize = (1 << oldorder);
1541 	newsize = (1 << (oldorder + 1));
1542 
1543 	mtx_lock(&ioat->cleanup_lock);
1544 
1545 	head = ioat->head & (oldsize - 1);
1546 	tail = ioat->tail & (oldsize - 1);
1547 
1548 	/* Copy old descriptors to new ring */
1549 	for (i = 0; i < oldsize; i++)
1550 		newring[i] = ioat->ring[i];
1551 
1552 	/*
1553 	 * If head has wrapped but tail hasn't, we must swap some descriptors
1554 	 * around so that tail can increment directly to head.
1555 	 */
1556 	if (head < tail) {
1557 		for (i = 0; i <= head; i++) {
1558 			tmp = newring[oldsize + i];
1559 
1560 			newring[oldsize + i] = newring[i];
1561 			newring[oldsize + i]->id = oldsize + i;
1562 
1563 			newring[i] = tmp;
1564 			newring[i]->id = i;
1565 		}
1566 		head += oldsize;
1567 	}
1568 
1569 	KASSERT(head >= tail, ("invariants"));
1570 
1571 	/* Head didn't wrap; we only need to link in oldsize..newsize */
1572 	if (head < oldsize) {
1573 		i = oldsize - 1;
1574 		end = newsize;
1575 	} else {
1576 		/* Head did wrap; link newhead..newsize and 0..oldhead */
1577 		i = head;
1578 		end = newsize + (head - oldsize) + 1;
1579 	}
1580 
1581 	/*
1582 	 * Fix up hardware ring, being careful not to trample the active
1583 	 * section (tail -> head).
1584 	 */
1585 	for (; i < end; i++) {
1586 		KASSERT((i & (newsize - 1)) < tail ||
1587 		    (i & (newsize - 1)) >= head, ("trampling snake"));
1588 
1589 		next = newring[(i + 1) & (newsize - 1)];
1590 		hw = newring[i & (newsize - 1)]->u.dma;
1591 		hw->next = next->hw_desc_bus_addr;
1592 	}
1593 
1594 #ifdef INVARIANTS
1595 	for (i = 0; i < newsize; i++) {
1596 		next = newring[(i + 1) & (newsize - 1)];
1597 		hw = newring[i & (newsize - 1)]->u.dma;
1598 
1599 		KASSERT(hw->next == next->hw_desc_bus_addr,
1600 		    ("mismatch at i:%u (oldsize:%u); next=%p nextaddr=0x%lx"
1601 		     " (tail:%u)", i, oldsize, next, next->hw_desc_bus_addr,
1602 		     tail));
1603 	}
1604 #endif
1605 
1606 	free(ioat->ring, M_IOAT);
1607 	ioat->ring = newring;
1608 	ioat->ring_size_order = oldorder + 1;
1609 	ioat->tail = tail;
1610 	ioat->head = head;
1611 	error = 0;
1612 
1613 	mtx_unlock(&ioat->cleanup_lock);
1614 out:
1615 	if (error)
1616 		ioat_free_ring(ioat, (1 << (oldorder + 1)), newring);
1617 	return (error);
1618 }
1619 
1620 static int
1621 ring_shrink(struct ioat_softc *ioat, uint32_t oldorder,
1622     struct ioat_descriptor **newring)
1623 {
1624 	struct ioat_dma_hw_descriptor *hw;
1625 	struct ioat_descriptor *ent, *next;
1626 	uint32_t oldsize, newsize, current_idx, new_idx, i;
1627 	int error;
1628 
1629 	CTR0(KTR_IOAT, __func__);
1630 
1631 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1632 
1633 	if (oldorder != ioat->ring_size_order || oldorder <= IOAT_MIN_ORDER) {
1634 		error = EINVAL;
1635 		goto out_unlocked;
1636 	}
1637 
1638 	oldsize = (1 << oldorder);
1639 	newsize = (1 << (oldorder - 1));
1640 
1641 	mtx_lock(&ioat->cleanup_lock);
1642 
1643 	/* Can't shrink below current active set! */
1644 	if (ioat_get_active(ioat) >= newsize) {
1645 		error = ENOMEM;
1646 		goto out;
1647 	}
1648 
1649 	/*
1650 	 * Copy current descriptors to the new ring, dropping the removed
1651 	 * descriptors.
1652 	 */
1653 	for (i = 0; i < newsize; i++) {
1654 		current_idx = (ioat->tail + i) & (oldsize - 1);
1655 		new_idx = (ioat->tail + i) & (newsize - 1);
1656 
1657 		newring[new_idx] = ioat->ring[current_idx];
1658 		newring[new_idx]->id = new_idx;
1659 	}
1660 
1661 	/* Free deleted descriptors */
1662 	for (i = newsize; i < oldsize; i++) {
1663 		ent = ioat_get_ring_entry(ioat, ioat->tail + i);
1664 		ioat_free_ring_entry(ioat, ent);
1665 	}
1666 
1667 	/* Fix up hardware ring. */
1668 	hw = newring[(ioat->tail + newsize - 1) & (newsize - 1)]->u.dma;
1669 	next = newring[(ioat->tail + newsize) & (newsize - 1)];
1670 	hw->next = next->hw_desc_bus_addr;
1671 
1672 #ifdef INVARIANTS
1673 	for (i = 0; i < newsize; i++) {
1674 		next = newring[(i + 1) & (newsize - 1)];
1675 		hw = newring[i & (newsize - 1)]->u.dma;
1676 
1677 		KASSERT(hw->next == next->hw_desc_bus_addr,
1678 		    ("mismatch at i:%u (newsize:%u); next=%p nextaddr=0x%lx "
1679 		     "(tail:%u)", i, newsize, next, next->hw_desc_bus_addr,
1680 		     ioat->tail));
1681 	}
1682 #endif
1683 
1684 	free(ioat->ring, M_IOAT);
1685 	ioat->ring = newring;
1686 	ioat->ring_size_order = oldorder - 1;
1687 	error = 0;
1688 
1689 out:
1690 	mtx_unlock(&ioat->cleanup_lock);
1691 out_unlocked:
1692 	if (error)
1693 		ioat_free_ring(ioat, (1 << (oldorder - 1)), newring);
1694 	return (error);
1695 }
1696 
1697 static void
1698 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1699 {
1700 	struct ioat_descriptor *desc;
1701 
1702 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1703 	    IOAT_CHANERR_STR);
1704 	if (chanerr == 0)
1705 		return;
1706 
1707 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1708 
1709 	desc = ioat_get_ring_entry(ioat, ioat->tail + 0);
1710 	dump_descriptor(desc->u.raw);
1711 
1712 	desc = ioat_get_ring_entry(ioat, ioat->tail + 1);
1713 	dump_descriptor(desc->u.raw);
1714 }
1715 
1716 static void
1717 ioat_poll_timer_callback(void *arg)
1718 {
1719 	struct ioat_softc *ioat;
1720 
1721 	ioat = arg;
1722 	ioat_log_message(3, "%s\n", __func__);
1723 
1724 	ioat_process_events(ioat);
1725 }
1726 
1727 static void
1728 ioat_shrink_timer_callback(void *arg)
1729 {
1730 	struct ioat_descriptor **newring;
1731 	struct ioat_softc *ioat;
1732 	uint32_t order;
1733 
1734 	ioat = arg;
1735 	ioat_log_message(1, "%s\n", __func__);
1736 
1737 	/* Slowly scale the ring down if idle. */
1738 	mtx_lock(&ioat->submit_lock);
1739 
1740 	/* Don't run while the hardware is being reset. */
1741 	if (ioat->resetting) {
1742 		mtx_unlock(&ioat->submit_lock);
1743 		return;
1744 	}
1745 
1746 	order = ioat->ring_size_order;
1747 	if (ioat->is_completion_pending || ioat->is_resize_pending ||
1748 	    order == IOAT_MIN_ORDER) {
1749 		mtx_unlock(&ioat->submit_lock);
1750 		goto out;
1751 	}
1752 	ioat->is_resize_pending = TRUE;
1753 	mtx_unlock(&ioat->submit_lock);
1754 
1755 	newring = ioat_prealloc_ring(ioat, 1 << (order - 1), FALSE,
1756 	    M_NOWAIT);
1757 
1758 	mtx_lock(&ioat->submit_lock);
1759 	KASSERT(ioat->ring_size_order == order,
1760 	    ("resize_pending protects order"));
1761 
1762 	if (newring != NULL && !ioat->is_completion_pending)
1763 		ring_shrink(ioat, order, newring);
1764 	else if (newring != NULL)
1765 		ioat_free_ring(ioat, (1 << (order - 1)), newring);
1766 
1767 	ioat->is_resize_pending = FALSE;
1768 	mtx_unlock(&ioat->submit_lock);
1769 
1770 out:
1771 	if (ioat->ring_size_order > IOAT_MIN_ORDER)
1772 		callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
1773 		    ioat_shrink_timer_callback, ioat);
1774 }
1775 
1776 /*
1777  * Support Functions
1778  */
1779 static void
1780 ioat_submit_single(struct ioat_softc *ioat)
1781 {
1782 
1783 	ioat_get(ioat, IOAT_ACTIVE_DESCR_REF);
1784 	atomic_add_rel_int(&ioat->head, 1);
1785 	atomic_add_rel_int(&ioat->hw_head, 1);
1786 
1787 	if (!ioat->is_completion_pending) {
1788 		ioat->is_completion_pending = TRUE;
1789 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
1790 		    ioat);
1791 		callout_stop(&ioat->shrink_timer);
1792 	}
1793 
1794 	ioat->stats.descriptors_submitted++;
1795 }
1796 
1797 static int
1798 ioat_reset_hw(struct ioat_softc *ioat)
1799 {
1800 	uint64_t status;
1801 	uint32_t chanerr;
1802 	unsigned timeout;
1803 	int error;
1804 
1805 	CTR0(KTR_IOAT, __func__);
1806 
1807 	mtx_lock(IOAT_REFLK);
1808 	while (ioat->resetting && !ioat->destroying)
1809 		msleep(&ioat->resetting, IOAT_REFLK, 0, "IRH_drain", 0);
1810 	if (ioat->destroying) {
1811 		mtx_unlock(IOAT_REFLK);
1812 		return (ENXIO);
1813 	}
1814 	ioat->resetting = TRUE;
1815 
1816 	ioat->quiescing = TRUE;
1817 	ioat_drain_locked(ioat);
1818 	mtx_unlock(IOAT_REFLK);
1819 
1820 	/*
1821 	 * Suspend ioat_process_events while the hardware and softc are in an
1822 	 * indeterminate state.
1823 	 */
1824 	mtx_lock(&ioat->cleanup_lock);
1825 	ioat->resetting_cleanup = TRUE;
1826 	mtx_unlock(&ioat->cleanup_lock);
1827 
1828 	status = ioat_get_chansts(ioat);
1829 	if (is_ioat_active(status) || is_ioat_idle(status))
1830 		ioat_suspend(ioat);
1831 
1832 	/* Wait at most 20 ms */
1833 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1834 	    timeout < 20; timeout++) {
1835 		DELAY(1000);
1836 		status = ioat_get_chansts(ioat);
1837 	}
1838 	if (timeout == 20) {
1839 		error = ETIMEDOUT;
1840 		goto out;
1841 	}
1842 
1843 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1844 
1845 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1846 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1847 
1848 	/*
1849 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1850 	 *  that can cause stability issues for IOAT v3.
1851 	 */
1852 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1853 	    4);
1854 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1855 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1856 
1857 	/*
1858 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1859 	 * Save/restore their contents manually.
1860 	 */
1861 	if (ioat_model_resets_msix(ioat)) {
1862 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1863 		pci_save_state(ioat->device);
1864 	}
1865 
1866 	ioat_reset(ioat);
1867 
1868 	/* Wait at most 20 ms */
1869 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1870 		DELAY(1000);
1871 	if (timeout == 20) {
1872 		error = ETIMEDOUT;
1873 		goto out;
1874 	}
1875 
1876 	if (ioat_model_resets_msix(ioat)) {
1877 		ioat_log_message(1, "device resets registers; restored\n");
1878 		pci_restore_state(ioat->device);
1879 	}
1880 
1881 	/* Reset attempts to return the hardware to "halted." */
1882 	status = ioat_get_chansts(ioat);
1883 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1884 		/* So this really shouldn't happen... */
1885 		ioat_log_message(0, "Device is active after a reset?\n");
1886 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1887 		error = 0;
1888 		goto out;
1889 	}
1890 
1891 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1892 	if (chanerr != 0) {
1893 		mtx_lock(&ioat->cleanup_lock);
1894 		ioat_halted_debug(ioat, chanerr);
1895 		mtx_unlock(&ioat->cleanup_lock);
1896 		error = EIO;
1897 		goto out;
1898 	}
1899 
1900 	/*
1901 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1902 	 * device back to active.
1903 	 *
1904 	 * The internal ring counter resets to zero, so we have to start over
1905 	 * at zero as well.
1906 	 */
1907 	ioat->tail = ioat->head = ioat->hw_head = 0;
1908 	ioat->last_seen = 0;
1909 	*ioat->comp_update = 0;
1910 
1911 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1912 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1913 	ioat_write_chainaddr(ioat, ioat->ring[0]->hw_desc_bus_addr);
1914 	error = 0;
1915 
1916 out:
1917 	/*
1918 	 * Resume completions now that ring state is consistent.
1919 	 * ioat_start_channel will add a pending completion and if we are still
1920 	 * blocking completions, we may livelock.
1921 	 */
1922 	mtx_lock(&ioat->cleanup_lock);
1923 	ioat->resetting_cleanup = FALSE;
1924 	mtx_unlock(&ioat->cleanup_lock);
1925 
1926 	/* Enqueues a null operation and ensures it completes. */
1927 	if (error == 0)
1928 		error = ioat_start_channel(ioat);
1929 
1930 	/* Unblock submission of new work */
1931 	mtx_lock(IOAT_REFLK);
1932 	ioat->quiescing = FALSE;
1933 	wakeup(&ioat->quiescing);
1934 
1935 	ioat->resetting = FALSE;
1936 	wakeup(&ioat->resetting);
1937 	mtx_unlock(IOAT_REFLK);
1938 
1939 	return (error);
1940 }
1941 
1942 static int
1943 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1944 {
1945 	struct ioat_softc *ioat;
1946 	struct sbuf sb;
1947 	uint64_t status;
1948 	int error;
1949 
1950 	ioat = arg1;
1951 
1952 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1953 
1954 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1955 	switch (status) {
1956 	case IOAT_CHANSTS_ACTIVE:
1957 		sbuf_printf(&sb, "ACTIVE");
1958 		break;
1959 	case IOAT_CHANSTS_IDLE:
1960 		sbuf_printf(&sb, "IDLE");
1961 		break;
1962 	case IOAT_CHANSTS_SUSPENDED:
1963 		sbuf_printf(&sb, "SUSPENDED");
1964 		break;
1965 	case IOAT_CHANSTS_HALTED:
1966 		sbuf_printf(&sb, "HALTED");
1967 		break;
1968 	case IOAT_CHANSTS_ARMED:
1969 		sbuf_printf(&sb, "ARMED");
1970 		break;
1971 	default:
1972 		sbuf_printf(&sb, "UNKNOWN");
1973 		break;
1974 	}
1975 	error = sbuf_finish(&sb);
1976 	sbuf_delete(&sb);
1977 
1978 	if (error != 0 || req->newptr == NULL)
1979 		return (error);
1980 	return (EINVAL);
1981 }
1982 
1983 static int
1984 sysctl_handle_dpi(SYSCTL_HANDLER_ARGS)
1985 {
1986 	struct ioat_softc *ioat;
1987 	struct sbuf sb;
1988 #define	PRECISION	"1"
1989 	const uintmax_t factor = 10;
1990 	uintmax_t rate;
1991 	int error;
1992 
1993 	ioat = arg1;
1994 	sbuf_new_for_sysctl(&sb, NULL, 16, req);
1995 
1996 	if (ioat->stats.interrupts == 0) {
1997 		sbuf_printf(&sb, "NaN");
1998 		goto out;
1999 	}
2000 	rate = ioat->stats.descriptors_processed * factor /
2001 	    ioat->stats.interrupts;
2002 	sbuf_printf(&sb, "%ju.%." PRECISION "ju", rate / factor,
2003 	    rate % factor);
2004 #undef	PRECISION
2005 out:
2006 	error = sbuf_finish(&sb);
2007 	sbuf_delete(&sb);
2008 	if (error != 0 || req->newptr == NULL)
2009 		return (error);
2010 	return (EINVAL);
2011 }
2012 
2013 static int
2014 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
2015 {
2016 	struct ioat_softc *ioat;
2017 	int error, arg;
2018 
2019 	ioat = arg1;
2020 
2021 	arg = 0;
2022 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
2023 	if (error != 0 || req->newptr == NULL)
2024 		return (error);
2025 
2026 	error = SYSCTL_IN(req, &arg, sizeof(arg));
2027 	if (error != 0)
2028 		return (error);
2029 
2030 	if (arg != 0)
2031 		error = ioat_reset_hw(ioat);
2032 
2033 	return (error);
2034 }
2035 
2036 static void
2037 dump_descriptor(void *hw_desc)
2038 {
2039 	int i, j;
2040 
2041 	for (i = 0; i < 2; i++) {
2042 		for (j = 0; j < 8; j++)
2043 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
2044 		printf("\n");
2045 	}
2046 }
2047 
2048 static void
2049 ioat_setup_sysctl(device_t device)
2050 {
2051 	struct sysctl_oid_list *par, *statpar, *state, *hammer;
2052 	struct sysctl_ctx_list *ctx;
2053 	struct sysctl_oid *tree, *tmp;
2054 	struct ioat_softc *ioat;
2055 
2056 	ioat = DEVICE2SOFTC(device);
2057 	ctx = device_get_sysctl_ctx(device);
2058 	tree = device_get_sysctl_tree(device);
2059 	par = SYSCTL_CHILDREN(tree);
2060 
2061 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
2062 	    &ioat->version, 0, "HW version (0xMM form)");
2063 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
2064 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
2065 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "intrdelay_supported", CTLFLAG_RD,
2066 	    &ioat->intrdelay_supported, 0, "Is INTRDELAY supported");
2067 	SYSCTL_ADD_U16(ctx, par, OID_AUTO, "intrdelay_max", CTLFLAG_RD,
2068 	    &ioat->intrdelay_max, 0,
2069 	    "Maximum configurable INTRDELAY on this channel (microseconds)");
2070 
2071 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "state", CTLFLAG_RD, NULL,
2072 	    "IOAT channel internal state");
2073 	state = SYSCTL_CHILDREN(tmp);
2074 
2075 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "ring_size_order", CTLFLAG_RD,
2076 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
2077 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "head", CTLFLAG_RD, &ioat->head,
2078 	    0, "SW descriptor head pointer index");
2079 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail,
2080 	    0, "SW descriptor tail pointer index");
2081 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "hw_head", CTLFLAG_RD,
2082 	    &ioat->hw_head, 0, "HW DMACOUNT");
2083 
2084 	SYSCTL_ADD_UQUAD(ctx, state, OID_AUTO, "last_completion", CTLFLAG_RD,
2085 	    ioat->comp_update, "HW addr of last completion");
2086 
2087 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_resize_pending", CTLFLAG_RD,
2088 	    &ioat->is_resize_pending, 0, "resize pending");
2089 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_submitter_processing",
2090 	    CTLFLAG_RD, &ioat->is_submitter_processing, 0,
2091 	    "submitter processing");
2092 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_completion_pending",
2093 	    CTLFLAG_RD, &ioat->is_completion_pending, 0, "completion pending");
2094 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_reset_pending", CTLFLAG_RD,
2095 	    &ioat->is_reset_pending, 0, "reset pending");
2096 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_channel_running", CTLFLAG_RD,
2097 	    &ioat->is_channel_running, 0, "channel running");
2098 
2099 	SYSCTL_ADD_PROC(ctx, state, OID_AUTO, "chansts",
2100 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
2101 	    "String of the channel status");
2102 
2103 	SYSCTL_ADD_U16(ctx, state, OID_AUTO, "intrdelay", CTLFLAG_RD,
2104 	    &ioat->cached_intrdelay, 0,
2105 	    "Current INTRDELAY on this channel (cached, microseconds)");
2106 
2107 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "hammer", CTLFLAG_RD, NULL,
2108 	    "Big hammers (mostly for testing)");
2109 	hammer = SYSCTL_CHILDREN(tmp);
2110 
2111 	SYSCTL_ADD_PROC(ctx, hammer, OID_AUTO, "force_hw_reset",
2112 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
2113 	    "Set to non-zero to reset the hardware");
2114 
2115 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "stats", CTLFLAG_RD, NULL,
2116 	    "IOAT channel statistics");
2117 	statpar = SYSCTL_CHILDREN(tmp);
2118 
2119 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "interrupts", CTLFLAG_RW,
2120 	    &ioat->stats.interrupts,
2121 	    "Number of interrupts processed on this channel");
2122 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "descriptors", CTLFLAG_RW,
2123 	    &ioat->stats.descriptors_processed,
2124 	    "Number of descriptors processed on this channel");
2125 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "submitted", CTLFLAG_RW,
2126 	    &ioat->stats.descriptors_submitted,
2127 	    "Number of descriptors submitted to this channel");
2128 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "errored", CTLFLAG_RW,
2129 	    &ioat->stats.descriptors_error,
2130 	    "Number of descriptors failed by channel errors");
2131 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "halts", CTLFLAG_RW,
2132 	    &ioat->stats.channel_halts, 0,
2133 	    "Number of times the channel has halted");
2134 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "last_halt_chanerr", CTLFLAG_RW,
2135 	    &ioat->stats.last_halt_chanerr, 0,
2136 	    "The raw CHANERR when the channel was last halted");
2137 
2138 	SYSCTL_ADD_PROC(ctx, statpar, OID_AUTO, "desc_per_interrupt",
2139 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_dpi, "A",
2140 	    "Descriptors per interrupt");
2141 }
2142 
2143 static inline struct ioat_softc *
2144 ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
2145 {
2146 	uint32_t old;
2147 
2148 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
2149 
2150 	old = atomic_fetchadd_32(&ioat->refcnt, 1);
2151 	KASSERT(old < UINT32_MAX, ("refcnt overflow"));
2152 
2153 #ifdef INVARIANTS
2154 	old = atomic_fetchadd_32(&ioat->refkinds[kind], 1);
2155 	KASSERT(old < UINT32_MAX, ("refcnt kind overflow"));
2156 #endif
2157 
2158 	return (ioat);
2159 }
2160 
2161 static inline void
2162 ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
2163 {
2164 
2165 	_ioat_putn(ioat, n, kind, FALSE);
2166 }
2167 
2168 static inline void
2169 ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
2170 {
2171 
2172 	_ioat_putn(ioat, n, kind, TRUE);
2173 }
2174 
2175 static inline void
2176 _ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
2177     boolean_t locked)
2178 {
2179 	uint32_t old;
2180 
2181 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
2182 
2183 	if (n == 0)
2184 		return;
2185 
2186 #ifdef INVARIANTS
2187 	old = atomic_fetchadd_32(&ioat->refkinds[kind], -n);
2188 	KASSERT(old >= n, ("refcnt kind underflow"));
2189 #endif
2190 
2191 	/* Skip acquiring the lock if resulting refcnt > 0. */
2192 	for (;;) {
2193 		old = ioat->refcnt;
2194 		if (old <= n)
2195 			break;
2196 		if (atomic_cmpset_32(&ioat->refcnt, old, old - n))
2197 			return;
2198 	}
2199 
2200 	if (locked)
2201 		mtx_assert(IOAT_REFLK, MA_OWNED);
2202 	else
2203 		mtx_lock(IOAT_REFLK);
2204 
2205 	old = atomic_fetchadd_32(&ioat->refcnt, -n);
2206 	KASSERT(old >= n, ("refcnt error"));
2207 
2208 	if (old == n)
2209 		wakeup(IOAT_REFLK);
2210 	if (!locked)
2211 		mtx_unlock(IOAT_REFLK);
2212 }
2213 
2214 static inline void
2215 ioat_put(struct ioat_softc *ioat, enum ioat_ref_kind kind)
2216 {
2217 
2218 	ioat_putn(ioat, 1, kind);
2219 }
2220 
2221 static void
2222 ioat_drain_locked(struct ioat_softc *ioat)
2223 {
2224 
2225 	mtx_assert(IOAT_REFLK, MA_OWNED);
2226 	while (ioat->refcnt > 0)
2227 		msleep(IOAT_REFLK, IOAT_REFLK, 0, "ioat_drain", 0);
2228 }
2229 
2230 #ifdef DDB
2231 #define	_db_show_lock(lo)	LOCK_CLASS(lo)->lc_ddb_show(lo)
2232 #define	db_show_lock(lk)	_db_show_lock(&(lk)->lock_object)
2233 DB_SHOW_COMMAND(ioat, db_show_ioat)
2234 {
2235 	struct ioat_softc *sc;
2236 	unsigned idx;
2237 
2238 	if (!have_addr)
2239 		goto usage;
2240 	idx = (unsigned)addr;
2241 	if (idx >= ioat_channel_index)
2242 		goto usage;
2243 
2244 	sc = ioat_channel[idx];
2245 	db_printf("ioat softc at %p\n", sc);
2246 	if (sc == NULL)
2247 		return;
2248 
2249 	db_printf(" version: %d\n", sc->version);
2250 	db_printf(" chan_idx: %u\n", sc->chan_idx);
2251 	db_printf(" submit_lock: ");
2252 	db_show_lock(&sc->submit_lock);
2253 
2254 	db_printf(" capabilities: %b\n", (int)sc->capabilities,
2255 	    IOAT_DMACAP_STR);
2256 	db_printf(" cached_intrdelay: %u\n", sc->cached_intrdelay);
2257 	db_printf(" *comp_update: 0x%jx\n", (uintmax_t)*sc->comp_update);
2258 
2259 	db_printf(" poll_timer:\n");
2260 	db_printf("  c_time: %ju\n", (uintmax_t)sc->poll_timer.c_time);
2261 	db_printf("  c_arg: %p\n", sc->poll_timer.c_arg);
2262 	db_printf("  c_func: %p\n", sc->poll_timer.c_func);
2263 	db_printf("  c_lock: %p\n", sc->poll_timer.c_lock);
2264 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->poll_timer.c_flags);
2265 
2266 	db_printf(" shrink_timer:\n");
2267 	db_printf("  c_time: %ju\n", (uintmax_t)sc->shrink_timer.c_time);
2268 	db_printf("  c_arg: %p\n", sc->shrink_timer.c_arg);
2269 	db_printf("  c_func: %p\n", sc->shrink_timer.c_func);
2270 	db_printf("  c_lock: %p\n", sc->shrink_timer.c_lock);
2271 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->shrink_timer.c_flags);
2272 
2273 	db_printf(" quiescing: %d\n", (int)sc->quiescing);
2274 	db_printf(" destroying: %d\n", (int)sc->destroying);
2275 	db_printf(" is_resize_pending: %d\n", (int)sc->is_resize_pending);
2276 	db_printf(" is_submitter_processing: %d\n",
2277 	    (int)sc->is_submitter_processing);
2278 	db_printf(" is_completion_pending: %d\n", (int)sc->is_completion_pending);
2279 	db_printf(" is_reset_pending: %d\n", (int)sc->is_reset_pending);
2280 	db_printf(" is_channel_running: %d\n", (int)sc->is_channel_running);
2281 	db_printf(" intrdelay_supported: %d\n", (int)sc->intrdelay_supported);
2282 	db_printf(" resetting: %d\n", (int)sc->resetting);
2283 
2284 	db_printf(" head: %u\n", sc->head);
2285 	db_printf(" tail: %u\n", sc->tail);
2286 	db_printf(" hw_head: %u\n", sc->hw_head);
2287 	db_printf(" ring_size_order: %u\n", sc->ring_size_order);
2288 	db_printf(" last_seen: 0x%lx\n", sc->last_seen);
2289 	db_printf(" ring: %p\n", sc->ring);
2290 
2291 	db_printf("  ring[%u] (tail):\n", sc->tail %
2292 	    (1 << sc->ring_size_order));
2293 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->tail)->id);
2294 	db_printf("   addr: 0x%lx\n",
2295 	    ioat_get_ring_entry(sc, sc->tail)->hw_desc_bus_addr);
2296 	db_printf("   next: 0x%lx\n",
2297 	    ioat_get_ring_entry(sc, sc->tail)->u.generic->next);
2298 
2299 	db_printf("  ring[%u] (head - 1):\n", (sc->head - 1) %
2300 	    (1 << sc->ring_size_order));
2301 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head - 1)->id);
2302 	db_printf("   addr: 0x%lx\n",
2303 	    ioat_get_ring_entry(sc, sc->head - 1)->hw_desc_bus_addr);
2304 	db_printf("   next: 0x%lx\n",
2305 	    ioat_get_ring_entry(sc, sc->head - 1)->u.generic->next);
2306 
2307 	db_printf("  ring[%u] (head):\n", (sc->head) %
2308 	    (1 << sc->ring_size_order));
2309 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head)->id);
2310 	db_printf("   addr: 0x%lx\n",
2311 	    ioat_get_ring_entry(sc, sc->head)->hw_desc_bus_addr);
2312 	db_printf("   next: 0x%lx\n",
2313 	    ioat_get_ring_entry(sc, sc->head)->u.generic->next);
2314 
2315 	for (idx = 0; idx < (1 << sc->ring_size_order); idx++)
2316 		if ((*sc->comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK)
2317 		    == ioat_get_ring_entry(sc, idx)->hw_desc_bus_addr)
2318 			db_printf("  ring[%u] == hardware tail\n", idx);
2319 
2320 	db_printf(" cleanup_lock: ");
2321 	db_show_lock(&sc->cleanup_lock);
2322 
2323 	db_printf(" refcnt: %u\n", sc->refcnt);
2324 #ifdef INVARIANTS
2325 	CTASSERT(IOAT_NUM_REF_KINDS == 2);
2326 	db_printf(" refkinds: [ENG=%u, DESCR=%u]\n", sc->refkinds[0],
2327 	    sc->refkinds[1]);
2328 #endif
2329 	db_printf(" stats:\n");
2330 	db_printf("  interrupts: %lu\n", sc->stats.interrupts);
2331 	db_printf("  descriptors_processed: %lu\n", sc->stats.descriptors_processed);
2332 	db_printf("  descriptors_error: %lu\n", sc->stats.descriptors_error);
2333 	db_printf("  descriptors_submitted: %lu\n", sc->stats.descriptors_submitted);
2334 
2335 	db_printf("  channel_halts: %u\n", sc->stats.channel_halts);
2336 	db_printf("  last_halt_chanerr: %u\n", sc->stats.last_halt_chanerr);
2337 
2338 	if (db_pager_quit)
2339 		return;
2340 
2341 	db_printf(" hw status:\n");
2342 	db_printf("  status: 0x%lx\n", ioat_get_chansts(sc));
2343 	db_printf("  chanctrl: 0x%x\n",
2344 	    (unsigned)ioat_read_2(sc, IOAT_CHANCTRL_OFFSET));
2345 	db_printf("  chancmd: 0x%x\n",
2346 	    (unsigned)ioat_read_1(sc, IOAT_CHANCMD_OFFSET));
2347 	db_printf("  dmacount: 0x%x\n",
2348 	    (unsigned)ioat_read_2(sc, IOAT_DMACOUNT_OFFSET));
2349 	db_printf("  chainaddr: 0x%lx\n",
2350 	    ioat_read_double_4(sc, IOAT_CHAINADDR_OFFSET_LOW));
2351 	db_printf("  chancmp: 0x%lx\n",
2352 	    ioat_read_double_4(sc, IOAT_CHANCMP_OFFSET_LOW));
2353 	db_printf("  chanerr: %b\n",
2354 	    (int)ioat_read_4(sc, IOAT_CHANERR_OFFSET), IOAT_CHANERR_STR);
2355 	return;
2356 usage:
2357 	db_printf("usage: show ioat <0-%u>\n", ioat_channel_index);
2358 	return;
2359 }
2360 #endif /* DDB */
2361