xref: /freebsd/sys/dev/ioat/ioat.c (revision 41b9077ef675c307fd1112bcea26aa3aeba1bb91)
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 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
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_get_chansts(ioat);
682 	CTR4(KTR_IOAT, "%s channel=%u hw_status=0x%lx last_seen=0x%lx",
683 	    __func__, ioat->chan_idx, comp_update, ioat->last_seen);
684 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
685 
686 	if (status == ioat->last_seen) {
687 		/*
688 		 * If we landed in process_events and nothing has been
689 		 * completed, check for a timeout due to channel halt.
690 		 */
691 		goto out;
692 	}
693 
694 	desc = ioat_get_ring_entry(ioat, ioat->tail - 1);
695 	while (desc->hw_desc_bus_addr != status && ioat_get_active(ioat) > 0) {
696 		desc = ioat_get_ring_entry(ioat, ioat->tail);
697 		dmadesc = &desc->bus_dmadesc;
698 		CTR4(KTR_IOAT, "channel=%u completing desc %u ok  cb %p(%p)",
699 		    ioat->chan_idx, ioat->tail, dmadesc->callback_fn,
700 		    dmadesc->callback_arg);
701 
702 		if (dmadesc->callback_fn != NULL)
703 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
704 
705 		completed++;
706 		ioat->tail++;
707 	}
708 
709 	if (completed != 0) {
710 		ioat->last_seen = desc->hw_desc_bus_addr;
711 		ioat->stats.descriptors_processed += completed;
712 	}
713 
714 out:
715 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
716 
717 	/* Perform a racy check first; only take the locks if it passes. */
718 	pending = (ioat_get_active(ioat) != 0);
719 	if (!pending && ioat->is_completion_pending) {
720 		mtx_unlock(&ioat->cleanup_lock);
721 		mtx_lock(&ioat->submit_lock);
722 		mtx_lock(&ioat->cleanup_lock);
723 
724 		pending = (ioat_get_active(ioat) != 0);
725 		if (!pending && ioat->is_completion_pending) {
726 			ioat->is_completion_pending = FALSE;
727 			callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
728 			    ioat_shrink_timer_callback, ioat);
729 			callout_stop(&ioat->poll_timer);
730 		}
731 		mtx_unlock(&ioat->submit_lock);
732 	}
733 	mtx_unlock(&ioat->cleanup_lock);
734 
735 	if (pending)
736 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
737 		    ioat);
738 
739 	if (completed != 0) {
740 		ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
741 		wakeup(&ioat->tail);
742 	}
743 
744 	if (!is_ioat_halted(comp_update) && !is_ioat_suspended(comp_update))
745 		return;
746 
747 	ioat->stats.channel_halts++;
748 
749 	/*
750 	 * Fatal programming error on this DMA channel.  Flush any outstanding
751 	 * work with error status and restart the engine.
752 	 */
753 	ioat_log_message(0, "Channel halted due to fatal programming error\n");
754 	mtx_lock(&ioat->submit_lock);
755 	mtx_lock(&ioat->cleanup_lock);
756 	ioat->quiescing = TRUE;
757 
758 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
759 	ioat_halted_debug(ioat, chanerr);
760 	ioat->stats.last_halt_chanerr = chanerr;
761 
762 	while (ioat_get_active(ioat) > 0) {
763 		desc = ioat_get_ring_entry(ioat, ioat->tail);
764 		dmadesc = &desc->bus_dmadesc;
765 		CTR4(KTR_IOAT, "channel=%u completing desc %u err cb %p(%p)",
766 		    ioat->chan_idx, ioat->tail, dmadesc->callback_fn,
767 		    dmadesc->callback_arg);
768 
769 		if (dmadesc->callback_fn != NULL)
770 			dmadesc->callback_fn(dmadesc->callback_arg,
771 			    chanerr_to_errno(chanerr));
772 
773 		ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
774 		ioat->tail++;
775 		ioat->stats.descriptors_processed++;
776 		ioat->stats.descriptors_error++;
777 	}
778 
779 	if (ioat->is_completion_pending) {
780 		ioat->is_completion_pending = FALSE;
781 		callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
782 		    ioat_shrink_timer_callback, ioat);
783 		callout_stop(&ioat->poll_timer);
784 	}
785 
786 	/* Clear error status */
787 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
788 
789 	mtx_unlock(&ioat->cleanup_lock);
790 	mtx_unlock(&ioat->submit_lock);
791 
792 	ioat_log_message(0, "Resetting channel to recover from error\n");
793 	error = taskqueue_enqueue(taskqueue_thread, &ioat->reset_task);
794 	KASSERT(error == 0,
795 	    ("%s: taskqueue_enqueue failed: %d", __func__, error));
796 }
797 
798 static void
799 ioat_reset_hw_task(void *ctx, int pending __unused)
800 {
801 	struct ioat_softc *ioat;
802 	int error;
803 
804 	ioat = ctx;
805 	ioat_log_message(1, "%s: Resetting channel\n", __func__);
806 
807 	error = ioat_reset_hw(ioat);
808 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
809 	(void)error;
810 }
811 
812 /*
813  * User API functions
814  */
815 unsigned
816 ioat_get_nchannels(void)
817 {
818 
819 	return (ioat_channel_index);
820 }
821 
822 bus_dmaengine_t
823 ioat_get_dmaengine(uint32_t index, int flags)
824 {
825 	struct ioat_softc *ioat;
826 
827 	KASSERT((flags & ~(M_NOWAIT | M_WAITOK)) == 0,
828 	    ("invalid flags: 0x%08x", flags));
829 	KASSERT((flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK),
830 	    ("invalid wait | nowait"));
831 
832 	if (index >= ioat_channel_index)
833 		return (NULL);
834 
835 	ioat = ioat_channel[index];
836 	if (ioat == NULL || ioat->destroying)
837 		return (NULL);
838 
839 	if (ioat->quiescing) {
840 		if ((flags & M_NOWAIT) != 0)
841 			return (NULL);
842 
843 		mtx_lock(IOAT_REFLK);
844 		while (ioat->quiescing && !ioat->destroying)
845 			msleep(&ioat->quiescing, IOAT_REFLK, 0, "getdma", 0);
846 		mtx_unlock(IOAT_REFLK);
847 
848 		if (ioat->destroying)
849 			return (NULL);
850 	}
851 
852 	/*
853 	 * There's a race here between the quiescing check and HW reset or
854 	 * module destroy.
855 	 */
856 	return (&ioat_get(ioat, IOAT_DMAENGINE_REF)->dmaengine);
857 }
858 
859 void
860 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
861 {
862 	struct ioat_softc *ioat;
863 
864 	ioat = to_ioat_softc(dmaengine);
865 	ioat_put(ioat, IOAT_DMAENGINE_REF);
866 }
867 
868 int
869 ioat_get_hwversion(bus_dmaengine_t dmaengine)
870 {
871 	struct ioat_softc *ioat;
872 
873 	ioat = to_ioat_softc(dmaengine);
874 	return (ioat->version);
875 }
876 
877 size_t
878 ioat_get_max_io_size(bus_dmaengine_t dmaengine)
879 {
880 	struct ioat_softc *ioat;
881 
882 	ioat = to_ioat_softc(dmaengine);
883 	return (ioat->max_xfer_size);
884 }
885 
886 uint32_t
887 ioat_get_capabilities(bus_dmaengine_t dmaengine)
888 {
889 	struct ioat_softc *ioat;
890 
891 	ioat = to_ioat_softc(dmaengine);
892 	return (ioat->capabilities);
893 }
894 
895 int
896 ioat_set_interrupt_coalesce(bus_dmaengine_t dmaengine, uint16_t delay)
897 {
898 	struct ioat_softc *ioat;
899 
900 	ioat = to_ioat_softc(dmaengine);
901 	if (!ioat->intrdelay_supported)
902 		return (ENODEV);
903 	if (delay > ioat->intrdelay_max)
904 		return (ERANGE);
905 
906 	ioat_write_2(ioat, IOAT_INTRDELAY_OFFSET, delay);
907 	ioat->cached_intrdelay =
908 	    ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) & IOAT_INTRDELAY_US_MASK;
909 	return (0);
910 }
911 
912 uint16_t
913 ioat_get_max_coalesce_period(bus_dmaengine_t dmaengine)
914 {
915 	struct ioat_softc *ioat;
916 
917 	ioat = to_ioat_softc(dmaengine);
918 	return (ioat->intrdelay_max);
919 }
920 
921 void
922 ioat_acquire(bus_dmaengine_t dmaengine)
923 {
924 	struct ioat_softc *ioat;
925 
926 	ioat = to_ioat_softc(dmaengine);
927 	mtx_lock(&ioat->submit_lock);
928 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
929 }
930 
931 int
932 ioat_acquire_reserve(bus_dmaengine_t dmaengine, unsigned n, int mflags)
933 {
934 	struct ioat_softc *ioat;
935 	int error;
936 
937 	ioat = to_ioat_softc(dmaengine);
938 	ioat_acquire(dmaengine);
939 
940 	error = ioat_reserve_space(ioat, n, mflags);
941 	if (error != 0)
942 		ioat_release(dmaengine);
943 	return (error);
944 }
945 
946 void
947 ioat_release(bus_dmaengine_t dmaengine)
948 {
949 	struct ioat_softc *ioat;
950 
951 	ioat = to_ioat_softc(dmaengine);
952 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
953 	ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET, (uint16_t)ioat->hw_head);
954 	mtx_unlock(&ioat->submit_lock);
955 }
956 
957 static struct ioat_descriptor *
958 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
959     uint32_t size, uint64_t src, uint64_t dst,
960     bus_dmaengine_callback_t callback_fn, void *callback_arg,
961     uint32_t flags)
962 {
963 	struct ioat_generic_hw_descriptor *hw_desc;
964 	struct ioat_descriptor *desc;
965 	int mflags;
966 
967 	mtx_assert(&ioat->submit_lock, MA_OWNED);
968 
969 	KASSERT((flags & ~_DMA_GENERIC_FLAGS) == 0,
970 	    ("Unrecognized flag(s): %#x", flags & ~_DMA_GENERIC_FLAGS));
971 	if ((flags & DMA_NO_WAIT) != 0)
972 		mflags = M_NOWAIT;
973 	else
974 		mflags = M_WAITOK;
975 
976 	if (size > ioat->max_xfer_size) {
977 		ioat_log_message(0, "%s: max_xfer_size = %d, requested = %u\n",
978 		    __func__, ioat->max_xfer_size, (unsigned)size);
979 		return (NULL);
980 	}
981 
982 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
983 		return (NULL);
984 
985 	desc = ioat_get_ring_entry(ioat, ioat->head);
986 	hw_desc = desc->u.generic;
987 
988 	hw_desc->u.control_raw = 0;
989 	hw_desc->u.control_generic.op = op;
990 	hw_desc->u.control_generic.completion_update = 1;
991 
992 	if ((flags & DMA_INT_EN) != 0)
993 		hw_desc->u.control_generic.int_enable = 1;
994 	if ((flags & DMA_FENCE) != 0)
995 		hw_desc->u.control_generic.fence = 1;
996 
997 	hw_desc->size = size;
998 	hw_desc->src_addr = src;
999 	hw_desc->dest_addr = dst;
1000 
1001 	desc->bus_dmadesc.callback_fn = callback_fn;
1002 	desc->bus_dmadesc.callback_arg = callback_arg;
1003 	return (desc);
1004 }
1005 
1006 struct bus_dmadesc *
1007 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
1008     void *callback_arg, uint32_t flags)
1009 {
1010 	struct ioat_dma_hw_descriptor *hw_desc;
1011 	struct ioat_descriptor *desc;
1012 	struct ioat_softc *ioat;
1013 
1014 	ioat = to_ioat_softc(dmaengine);
1015 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1016 
1017 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
1018 	    callback_arg, flags);
1019 	if (desc == NULL)
1020 		return (NULL);
1021 
1022 	hw_desc = desc->u.dma;
1023 	hw_desc->u.control.null = 1;
1024 	ioat_submit_single(ioat);
1025 	return (&desc->bus_dmadesc);
1026 }
1027 
1028 struct bus_dmadesc *
1029 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
1030     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
1031     void *callback_arg, uint32_t flags)
1032 {
1033 	struct ioat_dma_hw_descriptor *hw_desc;
1034 	struct ioat_descriptor *desc;
1035 	struct ioat_softc *ioat;
1036 
1037 	ioat = to_ioat_softc(dmaengine);
1038 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1039 
1040 	if (((src | dst) & (0xffffull << 48)) != 0) {
1041 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1042 		    __func__);
1043 		return (NULL);
1044 	}
1045 
1046 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
1047 	    callback_arg, flags);
1048 	if (desc == NULL)
1049 		return (NULL);
1050 
1051 	hw_desc = desc->u.dma;
1052 	if (g_ioat_debug_level >= 3)
1053 		dump_descriptor(hw_desc);
1054 
1055 	ioat_submit_single(ioat);
1056 	return (&desc->bus_dmadesc);
1057 }
1058 
1059 struct bus_dmadesc *
1060 ioat_copy_8k_aligned(bus_dmaengine_t dmaengine, bus_addr_t dst1,
1061     bus_addr_t dst2, bus_addr_t src1, bus_addr_t src2,
1062     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1063 {
1064 	struct ioat_dma_hw_descriptor *hw_desc;
1065 	struct ioat_descriptor *desc;
1066 	struct ioat_softc *ioat;
1067 
1068 	ioat = to_ioat_softc(dmaengine);
1069 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1070 
1071 	if (((src1 | src2 | dst1 | dst2) & (0xffffull << 48)) != 0) {
1072 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1073 		    __func__);
1074 		return (NULL);
1075 	}
1076 	if (((src1 | src2 | dst1 | dst2) & PAGE_MASK) != 0) {
1077 		ioat_log_message(0, "%s: Addresses must be page-aligned\n",
1078 		    __func__);
1079 		return (NULL);
1080 	}
1081 
1082 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 2 * PAGE_SIZE, src1, dst1,
1083 	    callback_fn, callback_arg, flags);
1084 	if (desc == NULL)
1085 		return (NULL);
1086 
1087 	hw_desc = desc->u.dma;
1088 	if (src2 != src1 + PAGE_SIZE) {
1089 		hw_desc->u.control.src_page_break = 1;
1090 		hw_desc->next_src_addr = src2;
1091 	}
1092 	if (dst2 != dst1 + PAGE_SIZE) {
1093 		hw_desc->u.control.dest_page_break = 1;
1094 		hw_desc->next_dest_addr = dst2;
1095 	}
1096 
1097 	if (g_ioat_debug_level >= 3)
1098 		dump_descriptor(hw_desc);
1099 
1100 	ioat_submit_single(ioat);
1101 	return (&desc->bus_dmadesc);
1102 }
1103 
1104 struct bus_dmadesc *
1105 ioat_copy_crc(bus_dmaengine_t dmaengine, bus_addr_t dst, bus_addr_t src,
1106     bus_size_t len, uint32_t *initialseed, bus_addr_t crcptr,
1107     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1108 {
1109 	struct ioat_crc32_hw_descriptor *hw_desc;
1110 	struct ioat_descriptor *desc;
1111 	struct ioat_softc *ioat;
1112 	uint32_t teststore;
1113 	uint8_t op;
1114 
1115 	ioat = to_ioat_softc(dmaengine);
1116 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1117 
1118 	if ((ioat->capabilities & IOAT_DMACAP_MOVECRC) == 0) {
1119 		ioat_log_message(0, "%s: Device lacks MOVECRC capability\n",
1120 		    __func__);
1121 		return (NULL);
1122 	}
1123 	if (((src | dst) & (0xffffffull << 40)) != 0) {
1124 		ioat_log_message(0, "%s: High 24 bits of src/dst invalid\n",
1125 		    __func__);
1126 		return (NULL);
1127 	}
1128 	teststore = (flags & _DMA_CRC_TESTSTORE);
1129 	if (teststore == _DMA_CRC_TESTSTORE) {
1130 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1131 		return (NULL);
1132 	}
1133 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1134 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1135 		    __func__);
1136 		return (NULL);
1137 	}
1138 
1139 	switch (teststore) {
1140 	case DMA_CRC_STORE:
1141 		op = IOAT_OP_MOVECRC_STORE;
1142 		break;
1143 	case DMA_CRC_TEST:
1144 		op = IOAT_OP_MOVECRC_TEST;
1145 		break;
1146 	default:
1147 		KASSERT(teststore == 0, ("bogus"));
1148 		op = IOAT_OP_MOVECRC;
1149 		break;
1150 	}
1151 
1152 	if ((flags & DMA_CRC_INLINE) == 0 &&
1153 	    (crcptr & (0xffffffull << 40)) != 0) {
1154 		ioat_log_message(0,
1155 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1156 		return (NULL);
1157 	}
1158 
1159 	desc = ioat_op_generic(ioat, op, len, src, dst, callback_fn,
1160 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1161 	if (desc == NULL)
1162 		return (NULL);
1163 
1164 	hw_desc = desc->u.crc32;
1165 
1166 	if ((flags & DMA_CRC_INLINE) == 0)
1167 		hw_desc->crc_address = crcptr;
1168 	else
1169 		hw_desc->u.control.crc_location = 1;
1170 
1171 	if (initialseed != NULL) {
1172 		hw_desc->u.control.use_seed = 1;
1173 		hw_desc->seed = *initialseed;
1174 	}
1175 
1176 	if (g_ioat_debug_level >= 3)
1177 		dump_descriptor(hw_desc);
1178 
1179 	ioat_submit_single(ioat);
1180 	return (&desc->bus_dmadesc);
1181 }
1182 
1183 struct bus_dmadesc *
1184 ioat_crc(bus_dmaengine_t dmaengine, bus_addr_t src, bus_size_t len,
1185     uint32_t *initialseed, bus_addr_t crcptr,
1186     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1187 {
1188 	struct ioat_crc32_hw_descriptor *hw_desc;
1189 	struct ioat_descriptor *desc;
1190 	struct ioat_softc *ioat;
1191 	uint32_t teststore;
1192 	uint8_t op;
1193 
1194 	ioat = to_ioat_softc(dmaengine);
1195 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1196 
1197 	if ((ioat->capabilities & IOAT_DMACAP_CRC) == 0) {
1198 		ioat_log_message(0, "%s: Device lacks CRC capability\n",
1199 		    __func__);
1200 		return (NULL);
1201 	}
1202 	if ((src & (0xffffffull << 40)) != 0) {
1203 		ioat_log_message(0, "%s: High 24 bits of src invalid\n",
1204 		    __func__);
1205 		return (NULL);
1206 	}
1207 	teststore = (flags & _DMA_CRC_TESTSTORE);
1208 	if (teststore == _DMA_CRC_TESTSTORE) {
1209 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1210 		return (NULL);
1211 	}
1212 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1213 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1214 		    __func__);
1215 		return (NULL);
1216 	}
1217 
1218 	switch (teststore) {
1219 	case DMA_CRC_STORE:
1220 		op = IOAT_OP_CRC_STORE;
1221 		break;
1222 	case DMA_CRC_TEST:
1223 		op = IOAT_OP_CRC_TEST;
1224 		break;
1225 	default:
1226 		KASSERT(teststore == 0, ("bogus"));
1227 		op = IOAT_OP_CRC;
1228 		break;
1229 	}
1230 
1231 	if ((flags & DMA_CRC_INLINE) == 0 &&
1232 	    (crcptr & (0xffffffull << 40)) != 0) {
1233 		ioat_log_message(0,
1234 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1235 		return (NULL);
1236 	}
1237 
1238 	desc = ioat_op_generic(ioat, op, len, src, 0, callback_fn,
1239 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1240 	if (desc == NULL)
1241 		return (NULL);
1242 
1243 	hw_desc = desc->u.crc32;
1244 
1245 	if ((flags & DMA_CRC_INLINE) == 0)
1246 		hw_desc->crc_address = crcptr;
1247 	else
1248 		hw_desc->u.control.crc_location = 1;
1249 
1250 	if (initialseed != NULL) {
1251 		hw_desc->u.control.use_seed = 1;
1252 		hw_desc->seed = *initialseed;
1253 	}
1254 
1255 	if (g_ioat_debug_level >= 3)
1256 		dump_descriptor(hw_desc);
1257 
1258 	ioat_submit_single(ioat);
1259 	return (&desc->bus_dmadesc);
1260 }
1261 
1262 struct bus_dmadesc *
1263 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
1264     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
1265     uint32_t flags)
1266 {
1267 	struct ioat_fill_hw_descriptor *hw_desc;
1268 	struct ioat_descriptor *desc;
1269 	struct ioat_softc *ioat;
1270 
1271 	ioat = to_ioat_softc(dmaengine);
1272 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1273 
1274 	if ((ioat->capabilities & IOAT_DMACAP_BFILL) == 0) {
1275 		ioat_log_message(0, "%s: Device lacks BFILL capability\n",
1276 		    __func__);
1277 		return (NULL);
1278 	}
1279 
1280 	if ((dst & (0xffffull << 48)) != 0) {
1281 		ioat_log_message(0, "%s: High 16 bits of dst invalid\n",
1282 		    __func__);
1283 		return (NULL);
1284 	}
1285 
1286 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, fillpattern, dst,
1287 	    callback_fn, callback_arg, flags);
1288 	if (desc == NULL)
1289 		return (NULL);
1290 
1291 	hw_desc = desc->u.fill;
1292 	if (g_ioat_debug_level >= 3)
1293 		dump_descriptor(hw_desc);
1294 
1295 	ioat_submit_single(ioat);
1296 	return (&desc->bus_dmadesc);
1297 }
1298 
1299 /*
1300  * Ring Management
1301  */
1302 static inline uint32_t
1303 ioat_get_active(struct ioat_softc *ioat)
1304 {
1305 
1306 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
1307 }
1308 
1309 static inline uint32_t
1310 ioat_get_ring_space(struct ioat_softc *ioat)
1311 {
1312 
1313 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
1314 }
1315 
1316 static struct ioat_descriptor *
1317 ioat_alloc_ring_entry(struct ioat_softc *ioat, int mflags)
1318 {
1319 	struct ioat_generic_hw_descriptor *hw_desc;
1320 	struct ioat_descriptor *desc;
1321 	int error, busdmaflag;
1322 
1323 	error = ENOMEM;
1324 	hw_desc = NULL;
1325 
1326 	if ((mflags & M_WAITOK) != 0)
1327 		busdmaflag = BUS_DMA_WAITOK;
1328 	else
1329 		busdmaflag = BUS_DMA_NOWAIT;
1330 
1331 	desc = malloc(sizeof(*desc), M_IOAT, mflags);
1332 	if (desc == NULL)
1333 		goto out;
1334 
1335 	bus_dmamem_alloc(ioat->hw_desc_tag, (void **)&hw_desc,
1336 	    BUS_DMA_ZERO | busdmaflag, &ioat->hw_desc_map);
1337 	if (hw_desc == NULL)
1338 		goto out;
1339 
1340 	memset(&desc->bus_dmadesc, 0, sizeof(desc->bus_dmadesc));
1341 	desc->u.generic = hw_desc;
1342 
1343 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
1344 	    sizeof(*hw_desc), ioat_dmamap_cb, &desc->hw_desc_bus_addr,
1345 	    busdmaflag);
1346 	if (error)
1347 		goto out;
1348 
1349 out:
1350 	if (error) {
1351 		ioat_free_ring_entry(ioat, desc);
1352 		return (NULL);
1353 	}
1354 	return (desc);
1355 }
1356 
1357 static void
1358 ioat_free_ring_entry(struct ioat_softc *ioat, struct ioat_descriptor *desc)
1359 {
1360 
1361 	if (desc == NULL)
1362 		return;
1363 
1364 	if (desc->u.generic)
1365 		bus_dmamem_free(ioat->hw_desc_tag, desc->u.generic,
1366 		    ioat->hw_desc_map);
1367 	free(desc, M_IOAT);
1368 }
1369 
1370 /*
1371  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
1372  * for 'num_descs'.
1373  *
1374  * If mflags contains M_WAITOK, blocks until enough space is available.
1375  *
1376  * Returns zero on success, or an errno on error.  If num_descs is beyond the
1377  * maximum ring size, returns EINVAl; if allocation would block and mflags
1378  * contains M_NOWAIT, returns EAGAIN.
1379  *
1380  * Must be called with the submit_lock held; returns with the lock held.  The
1381  * lock may be dropped to allocate the ring.
1382  *
1383  * (The submit_lock is needed to add any entries to the ring, so callers are
1384  * assured enough room is available.)
1385  */
1386 static int
1387 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
1388 {
1389 	struct ioat_descriptor **new_ring;
1390 	uint32_t order;
1391 	boolean_t dug;
1392 	int error;
1393 
1394 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1395 	error = 0;
1396 	dug = FALSE;
1397 
1398 	if (num_descs < 1 || num_descs >= (1 << IOAT_MAX_ORDER)) {
1399 		error = EINVAL;
1400 		goto out;
1401 	}
1402 
1403 	for (;;) {
1404 		if (ioat->quiescing) {
1405 			error = ENXIO;
1406 			goto out;
1407 		}
1408 
1409 		if (ioat_get_ring_space(ioat) >= num_descs)
1410 			goto out;
1411 
1412 		if (!dug && !ioat->is_submitter_processing &&
1413 		    (1 << ioat->ring_size_order) > num_descs) {
1414 			ioat->is_submitter_processing = TRUE;
1415 			mtx_unlock(&ioat->submit_lock);
1416 
1417 			ioat_process_events(ioat);
1418 
1419 			mtx_lock(&ioat->submit_lock);
1420 			dug = TRUE;
1421 			KASSERT(ioat->is_submitter_processing == TRUE,
1422 			    ("is_submitter_processing"));
1423 			ioat->is_submitter_processing = FALSE;
1424 			wakeup(&ioat->tail);
1425 			continue;
1426 		}
1427 
1428 		order = ioat->ring_size_order;
1429 		if (ioat->is_resize_pending || order == IOAT_MAX_ORDER) {
1430 			if ((mflags & M_WAITOK) != 0) {
1431 				msleep(&ioat->tail, &ioat->submit_lock, 0,
1432 				    "ioat_rsz", 0);
1433 				continue;
1434 			}
1435 
1436 			error = EAGAIN;
1437 			break;
1438 		}
1439 
1440 		ioat->is_resize_pending = TRUE;
1441 		for (;;) {
1442 			mtx_unlock(&ioat->submit_lock);
1443 
1444 			new_ring = ioat_prealloc_ring(ioat, 1 << (order + 1),
1445 			    TRUE, mflags);
1446 
1447 			mtx_lock(&ioat->submit_lock);
1448 			KASSERT(ioat->ring_size_order == order,
1449 			    ("is_resize_pending should protect order"));
1450 
1451 			if (new_ring == NULL) {
1452 				KASSERT((mflags & M_WAITOK) == 0,
1453 				    ("allocation failed"));
1454 				error = EAGAIN;
1455 				break;
1456 			}
1457 
1458 			error = ring_grow(ioat, order, new_ring);
1459 			if (error == 0)
1460 				break;
1461 		}
1462 		ioat->is_resize_pending = FALSE;
1463 		wakeup(&ioat->tail);
1464 		if (error)
1465 			break;
1466 	}
1467 
1468 out:
1469 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1470 	KASSERT(!ioat->quiescing || error == ENXIO,
1471 	    ("reserved during quiesce"));
1472 	return (error);
1473 }
1474 
1475 static struct ioat_descriptor **
1476 ioat_prealloc_ring(struct ioat_softc *ioat, uint32_t size, boolean_t need_dscr,
1477     int mflags)
1478 {
1479 	struct ioat_descriptor **ring;
1480 	uint32_t i;
1481 	int error;
1482 
1483 	KASSERT(size > 0 && powerof2(size), ("bogus size"));
1484 
1485 	ring = malloc(size * sizeof(*ring), M_IOAT, M_ZERO | mflags);
1486 	if (ring == NULL)
1487 		return (NULL);
1488 
1489 	if (need_dscr) {
1490 		error = ENOMEM;
1491 		for (i = size / 2; i < size; i++) {
1492 			ring[i] = ioat_alloc_ring_entry(ioat, mflags);
1493 			if (ring[i] == NULL)
1494 				goto out;
1495 			ring[i]->id = i;
1496 		}
1497 	}
1498 	error = 0;
1499 
1500 out:
1501 	if (error != 0 && ring != NULL) {
1502 		ioat_free_ring(ioat, size, ring);
1503 		ring = NULL;
1504 	}
1505 	return (ring);
1506 }
1507 
1508 static void
1509 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1510     struct ioat_descriptor **ring)
1511 {
1512 	uint32_t i;
1513 
1514 	for (i = 0; i < size; i++) {
1515 		if (ring[i] != NULL)
1516 			ioat_free_ring_entry(ioat, ring[i]);
1517 	}
1518 	free(ring, M_IOAT);
1519 }
1520 
1521 static struct ioat_descriptor *
1522 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1523 {
1524 
1525 	return (ioat->ring[index % (1 << ioat->ring_size_order)]);
1526 }
1527 
1528 static int
1529 ring_grow(struct ioat_softc *ioat, uint32_t oldorder,
1530     struct ioat_descriptor **newring)
1531 {
1532 	struct ioat_descriptor *tmp, *next;
1533 	struct ioat_dma_hw_descriptor *hw;
1534 	uint32_t oldsize, newsize, head, tail, i, end;
1535 	int error;
1536 
1537 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1538 
1539 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1540 
1541 	if (oldorder != ioat->ring_size_order || oldorder >= IOAT_MAX_ORDER) {
1542 		error = EINVAL;
1543 		goto out;
1544 	}
1545 
1546 	oldsize = (1 << oldorder);
1547 	newsize = (1 << (oldorder + 1));
1548 
1549 	mtx_lock(&ioat->cleanup_lock);
1550 
1551 	head = ioat->head & (oldsize - 1);
1552 	tail = ioat->tail & (oldsize - 1);
1553 
1554 	/* Copy old descriptors to new ring */
1555 	for (i = 0; i < oldsize; i++)
1556 		newring[i] = ioat->ring[i];
1557 
1558 	/*
1559 	 * If head has wrapped but tail hasn't, we must swap some descriptors
1560 	 * around so that tail can increment directly to head.
1561 	 */
1562 	if (head < tail) {
1563 		for (i = 0; i <= head; i++) {
1564 			tmp = newring[oldsize + i];
1565 
1566 			newring[oldsize + i] = newring[i];
1567 			newring[oldsize + i]->id = oldsize + i;
1568 
1569 			newring[i] = tmp;
1570 			newring[i]->id = i;
1571 		}
1572 		head += oldsize;
1573 	}
1574 
1575 	KASSERT(head >= tail, ("invariants"));
1576 
1577 	/* Head didn't wrap; we only need to link in oldsize..newsize */
1578 	if (head < oldsize) {
1579 		i = oldsize - 1;
1580 		end = newsize;
1581 	} else {
1582 		/* Head did wrap; link newhead..newsize and 0..oldhead */
1583 		i = head;
1584 		end = newsize + (head - oldsize) + 1;
1585 	}
1586 
1587 	/*
1588 	 * Fix up hardware ring, being careful not to trample the active
1589 	 * section (tail -> head).
1590 	 */
1591 	for (; i < end; i++) {
1592 		KASSERT((i & (newsize - 1)) < tail ||
1593 		    (i & (newsize - 1)) >= head, ("trampling snake"));
1594 
1595 		next = newring[(i + 1) & (newsize - 1)];
1596 		hw = newring[i & (newsize - 1)]->u.dma;
1597 		hw->next = next->hw_desc_bus_addr;
1598 	}
1599 
1600 #ifdef INVARIANTS
1601 	for (i = 0; i < newsize; i++) {
1602 		next = newring[(i + 1) & (newsize - 1)];
1603 		hw = newring[i & (newsize - 1)]->u.dma;
1604 
1605 		KASSERT(hw->next == next->hw_desc_bus_addr,
1606 		    ("mismatch at i:%u (oldsize:%u); next=%p nextaddr=0x%lx"
1607 		     " (tail:%u)", i, oldsize, next, next->hw_desc_bus_addr,
1608 		     tail));
1609 	}
1610 #endif
1611 
1612 	free(ioat->ring, M_IOAT);
1613 	ioat->ring = newring;
1614 	ioat->ring_size_order = oldorder + 1;
1615 	ioat->tail = tail;
1616 	ioat->head = head;
1617 	error = 0;
1618 
1619 	mtx_unlock(&ioat->cleanup_lock);
1620 out:
1621 	if (error)
1622 		ioat_free_ring(ioat, (1 << (oldorder + 1)), newring);
1623 	return (error);
1624 }
1625 
1626 static int
1627 ring_shrink(struct ioat_softc *ioat, uint32_t oldorder,
1628     struct ioat_descriptor **newring)
1629 {
1630 	struct ioat_dma_hw_descriptor *hw;
1631 	struct ioat_descriptor *ent, *next;
1632 	uint32_t oldsize, newsize, current_idx, new_idx, i;
1633 	int error;
1634 
1635 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1636 
1637 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1638 
1639 	if (oldorder != ioat->ring_size_order || oldorder <= IOAT_MIN_ORDER) {
1640 		error = EINVAL;
1641 		goto out_unlocked;
1642 	}
1643 
1644 	oldsize = (1 << oldorder);
1645 	newsize = (1 << (oldorder - 1));
1646 
1647 	mtx_lock(&ioat->cleanup_lock);
1648 
1649 	/* Can't shrink below current active set! */
1650 	if (ioat_get_active(ioat) >= newsize) {
1651 		error = ENOMEM;
1652 		goto out;
1653 	}
1654 
1655 	/*
1656 	 * Copy current descriptors to the new ring, dropping the removed
1657 	 * descriptors.
1658 	 */
1659 	for (i = 0; i < newsize; i++) {
1660 		current_idx = (ioat->tail + i) & (oldsize - 1);
1661 		new_idx = (ioat->tail + i) & (newsize - 1);
1662 
1663 		newring[new_idx] = ioat->ring[current_idx];
1664 		newring[new_idx]->id = new_idx;
1665 	}
1666 
1667 	/* Free deleted descriptors */
1668 	for (i = newsize; i < oldsize; i++) {
1669 		ent = ioat_get_ring_entry(ioat, ioat->tail + i);
1670 		ioat_free_ring_entry(ioat, ent);
1671 	}
1672 
1673 	/* Fix up hardware ring. */
1674 	hw = newring[(ioat->tail + newsize - 1) & (newsize - 1)]->u.dma;
1675 	next = newring[(ioat->tail + newsize) & (newsize - 1)];
1676 	hw->next = next->hw_desc_bus_addr;
1677 
1678 #ifdef INVARIANTS
1679 	for (i = 0; i < newsize; i++) {
1680 		next = newring[(i + 1) & (newsize - 1)];
1681 		hw = newring[i & (newsize - 1)]->u.dma;
1682 
1683 		KASSERT(hw->next == next->hw_desc_bus_addr,
1684 		    ("mismatch at i:%u (newsize:%u); next=%p nextaddr=0x%lx "
1685 		     "(tail:%u)", i, newsize, next, next->hw_desc_bus_addr,
1686 		     ioat->tail));
1687 	}
1688 #endif
1689 
1690 	free(ioat->ring, M_IOAT);
1691 	ioat->ring = newring;
1692 	ioat->ring_size_order = oldorder - 1;
1693 	error = 0;
1694 
1695 out:
1696 	mtx_unlock(&ioat->cleanup_lock);
1697 out_unlocked:
1698 	if (error)
1699 		ioat_free_ring(ioat, (1 << (oldorder - 1)), newring);
1700 	return (error);
1701 }
1702 
1703 static void
1704 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1705 {
1706 	struct ioat_descriptor *desc;
1707 
1708 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1709 	    IOAT_CHANERR_STR);
1710 	if (chanerr == 0)
1711 		return;
1712 
1713 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1714 
1715 	desc = ioat_get_ring_entry(ioat, ioat->tail + 0);
1716 	dump_descriptor(desc->u.raw);
1717 
1718 	desc = ioat_get_ring_entry(ioat, ioat->tail + 1);
1719 	dump_descriptor(desc->u.raw);
1720 }
1721 
1722 static void
1723 ioat_poll_timer_callback(void *arg)
1724 {
1725 	struct ioat_softc *ioat;
1726 
1727 	ioat = arg;
1728 	ioat_log_message(3, "%s\n", __func__);
1729 
1730 	ioat_process_events(ioat);
1731 }
1732 
1733 static void
1734 ioat_shrink_timer_callback(void *arg)
1735 {
1736 	struct ioat_descriptor **newring;
1737 	struct ioat_softc *ioat;
1738 	uint32_t order;
1739 
1740 	ioat = arg;
1741 	ioat_log_message(1, "%s\n", __func__);
1742 
1743 	/* Slowly scale the ring down if idle. */
1744 	mtx_lock(&ioat->submit_lock);
1745 
1746 	/* Don't run while the hardware is being reset. */
1747 	if (ioat->resetting) {
1748 		mtx_unlock(&ioat->submit_lock);
1749 		return;
1750 	}
1751 
1752 	order = ioat->ring_size_order;
1753 	if (ioat->is_completion_pending || ioat->is_resize_pending ||
1754 	    order == IOAT_MIN_ORDER) {
1755 		mtx_unlock(&ioat->submit_lock);
1756 		goto out;
1757 	}
1758 	ioat->is_resize_pending = TRUE;
1759 	mtx_unlock(&ioat->submit_lock);
1760 
1761 	newring = ioat_prealloc_ring(ioat, 1 << (order - 1), FALSE,
1762 	    M_NOWAIT);
1763 
1764 	mtx_lock(&ioat->submit_lock);
1765 	KASSERT(ioat->ring_size_order == order,
1766 	    ("resize_pending protects order"));
1767 
1768 	if (newring != NULL && !ioat->is_completion_pending)
1769 		ring_shrink(ioat, order, newring);
1770 	else if (newring != NULL)
1771 		ioat_free_ring(ioat, (1 << (order - 1)), newring);
1772 
1773 	ioat->is_resize_pending = FALSE;
1774 	mtx_unlock(&ioat->submit_lock);
1775 
1776 out:
1777 	if (ioat->ring_size_order > IOAT_MIN_ORDER)
1778 		callout_reset(&ioat->shrink_timer, IOAT_SHRINK_PERIOD,
1779 		    ioat_shrink_timer_callback, ioat);
1780 }
1781 
1782 /*
1783  * Support Functions
1784  */
1785 static void
1786 ioat_submit_single(struct ioat_softc *ioat)
1787 {
1788 
1789 	ioat_get(ioat, IOAT_ACTIVE_DESCR_REF);
1790 	atomic_add_rel_int(&ioat->head, 1);
1791 	atomic_add_rel_int(&ioat->hw_head, 1);
1792 
1793 	if (!ioat->is_completion_pending) {
1794 		ioat->is_completion_pending = TRUE;
1795 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
1796 		    ioat);
1797 		callout_stop(&ioat->shrink_timer);
1798 	}
1799 
1800 	ioat->stats.descriptors_submitted++;
1801 }
1802 
1803 static int
1804 ioat_reset_hw(struct ioat_softc *ioat)
1805 {
1806 	uint64_t status;
1807 	uint32_t chanerr;
1808 	unsigned timeout;
1809 	int error;
1810 
1811 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1812 
1813 	mtx_lock(IOAT_REFLK);
1814 	while (ioat->resetting && !ioat->destroying)
1815 		msleep(&ioat->resetting, IOAT_REFLK, 0, "IRH_drain", 0);
1816 	if (ioat->destroying) {
1817 		mtx_unlock(IOAT_REFLK);
1818 		return (ENXIO);
1819 	}
1820 	ioat->resetting = TRUE;
1821 
1822 	ioat->quiescing = TRUE;
1823 	ioat_drain_locked(ioat);
1824 	mtx_unlock(IOAT_REFLK);
1825 
1826 	/*
1827 	 * Suspend ioat_process_events while the hardware and softc are in an
1828 	 * indeterminate state.
1829 	 */
1830 	mtx_lock(&ioat->cleanup_lock);
1831 	ioat->resetting_cleanup = TRUE;
1832 	mtx_unlock(&ioat->cleanup_lock);
1833 
1834 	CTR2(KTR_IOAT, "%s channel=%u quiesced and drained", __func__,
1835 	    ioat->chan_idx);
1836 
1837 	status = ioat_get_chansts(ioat);
1838 	if (is_ioat_active(status) || is_ioat_idle(status))
1839 		ioat_suspend(ioat);
1840 
1841 	/* Wait at most 20 ms */
1842 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1843 	    timeout < 20; timeout++) {
1844 		DELAY(1000);
1845 		status = ioat_get_chansts(ioat);
1846 	}
1847 	if (timeout == 20) {
1848 		error = ETIMEDOUT;
1849 		goto out;
1850 	}
1851 
1852 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1853 
1854 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1855 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1856 
1857 	CTR2(KTR_IOAT, "%s channel=%u hardware suspended", __func__,
1858 	    ioat->chan_idx);
1859 
1860 	/*
1861 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1862 	 *  that can cause stability issues for IOAT v3.
1863 	 */
1864 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1865 	    4);
1866 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1867 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1868 
1869 	/*
1870 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1871 	 * Save/restore their contents manually.
1872 	 */
1873 	if (ioat_model_resets_msix(ioat)) {
1874 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1875 		pci_save_state(ioat->device);
1876 	}
1877 
1878 	ioat_reset(ioat);
1879 	CTR2(KTR_IOAT, "%s channel=%u hardware reset", __func__,
1880 	    ioat->chan_idx);
1881 
1882 	/* Wait at most 20 ms */
1883 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1884 		DELAY(1000);
1885 	if (timeout == 20) {
1886 		error = ETIMEDOUT;
1887 		goto out;
1888 	}
1889 
1890 	if (ioat_model_resets_msix(ioat)) {
1891 		ioat_log_message(1, "device resets registers; restored\n");
1892 		pci_restore_state(ioat->device);
1893 	}
1894 
1895 	/* Reset attempts to return the hardware to "halted." */
1896 	status = ioat_get_chansts(ioat);
1897 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1898 		/* So this really shouldn't happen... */
1899 		ioat_log_message(0, "Device is active after a reset?\n");
1900 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1901 		error = 0;
1902 		goto out;
1903 	}
1904 
1905 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1906 	if (chanerr != 0) {
1907 		mtx_lock(&ioat->cleanup_lock);
1908 		ioat_halted_debug(ioat, chanerr);
1909 		mtx_unlock(&ioat->cleanup_lock);
1910 		error = EIO;
1911 		goto out;
1912 	}
1913 
1914 	/*
1915 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1916 	 * device back to active.
1917 	 *
1918 	 * The internal ring counter resets to zero, so we have to start over
1919 	 * at zero as well.
1920 	 */
1921 	ioat->tail = ioat->head = ioat->hw_head = 0;
1922 	ioat->last_seen = 0;
1923 	*ioat->comp_update = 0;
1924 	KASSERT(!ioat->is_completion_pending, ("bogus completion_pending"));
1925 
1926 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1927 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1928 	ioat_write_chainaddr(ioat, ioat->ring[0]->hw_desc_bus_addr);
1929 	error = 0;
1930 	CTR2(KTR_IOAT, "%s channel=%u configured channel", __func__,
1931 	    ioat->chan_idx);
1932 
1933 out:
1934 	/* Enqueues a null operation and ensures it completes. */
1935 	if (error == 0) {
1936 		error = ioat_start_channel(ioat);
1937 		CTR2(KTR_IOAT, "%s channel=%u started channel", __func__,
1938 		    ioat->chan_idx);
1939 	}
1940 
1941 	/*
1942 	 * Resume completions now that ring state is consistent.
1943 	 */
1944 	mtx_lock(&ioat->cleanup_lock);
1945 	ioat->resetting_cleanup = FALSE;
1946 	mtx_unlock(&ioat->cleanup_lock);
1947 
1948 	/* Unblock submission of new work */
1949 	mtx_lock(IOAT_REFLK);
1950 	ioat->quiescing = FALSE;
1951 	wakeup(&ioat->quiescing);
1952 
1953 	ioat->resetting = FALSE;
1954 	wakeup(&ioat->resetting);
1955 
1956 	if (ioat->is_completion_pending)
1957 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
1958 		    ioat);
1959 	CTR2(KTR_IOAT, "%s channel=%u reset done", __func__, ioat->chan_idx);
1960 	mtx_unlock(IOAT_REFLK);
1961 
1962 	return (error);
1963 }
1964 
1965 static int
1966 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1967 {
1968 	struct ioat_softc *ioat;
1969 	struct sbuf sb;
1970 	uint64_t status;
1971 	int error;
1972 
1973 	ioat = arg1;
1974 
1975 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1976 
1977 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1978 	switch (status) {
1979 	case IOAT_CHANSTS_ACTIVE:
1980 		sbuf_printf(&sb, "ACTIVE");
1981 		break;
1982 	case IOAT_CHANSTS_IDLE:
1983 		sbuf_printf(&sb, "IDLE");
1984 		break;
1985 	case IOAT_CHANSTS_SUSPENDED:
1986 		sbuf_printf(&sb, "SUSPENDED");
1987 		break;
1988 	case IOAT_CHANSTS_HALTED:
1989 		sbuf_printf(&sb, "HALTED");
1990 		break;
1991 	case IOAT_CHANSTS_ARMED:
1992 		sbuf_printf(&sb, "ARMED");
1993 		break;
1994 	default:
1995 		sbuf_printf(&sb, "UNKNOWN");
1996 		break;
1997 	}
1998 	error = sbuf_finish(&sb);
1999 	sbuf_delete(&sb);
2000 
2001 	if (error != 0 || req->newptr == NULL)
2002 		return (error);
2003 	return (EINVAL);
2004 }
2005 
2006 static int
2007 sysctl_handle_dpi(SYSCTL_HANDLER_ARGS)
2008 {
2009 	struct ioat_softc *ioat;
2010 	struct sbuf sb;
2011 #define	PRECISION	"1"
2012 	const uintmax_t factor = 10;
2013 	uintmax_t rate;
2014 	int error;
2015 
2016 	ioat = arg1;
2017 	sbuf_new_for_sysctl(&sb, NULL, 16, req);
2018 
2019 	if (ioat->stats.interrupts == 0) {
2020 		sbuf_printf(&sb, "NaN");
2021 		goto out;
2022 	}
2023 	rate = ioat->stats.descriptors_processed * factor /
2024 	    ioat->stats.interrupts;
2025 	sbuf_printf(&sb, "%ju.%." PRECISION "ju", rate / factor,
2026 	    rate % factor);
2027 #undef	PRECISION
2028 out:
2029 	error = sbuf_finish(&sb);
2030 	sbuf_delete(&sb);
2031 	if (error != 0 || req->newptr == NULL)
2032 		return (error);
2033 	return (EINVAL);
2034 }
2035 
2036 static int
2037 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
2038 {
2039 	struct ioat_softc *ioat;
2040 	int error, arg;
2041 
2042 	ioat = arg1;
2043 
2044 	arg = 0;
2045 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
2046 	if (error != 0 || req->newptr == NULL)
2047 		return (error);
2048 
2049 	error = SYSCTL_IN(req, &arg, sizeof(arg));
2050 	if (error != 0)
2051 		return (error);
2052 
2053 	if (arg != 0)
2054 		error = ioat_reset_hw(ioat);
2055 
2056 	return (error);
2057 }
2058 
2059 static void
2060 dump_descriptor(void *hw_desc)
2061 {
2062 	int i, j;
2063 
2064 	for (i = 0; i < 2; i++) {
2065 		for (j = 0; j < 8; j++)
2066 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
2067 		printf("\n");
2068 	}
2069 }
2070 
2071 static void
2072 ioat_setup_sysctl(device_t device)
2073 {
2074 	struct sysctl_oid_list *par, *statpar, *state, *hammer;
2075 	struct sysctl_ctx_list *ctx;
2076 	struct sysctl_oid *tree, *tmp;
2077 	struct ioat_softc *ioat;
2078 
2079 	ioat = DEVICE2SOFTC(device);
2080 	ctx = device_get_sysctl_ctx(device);
2081 	tree = device_get_sysctl_tree(device);
2082 	par = SYSCTL_CHILDREN(tree);
2083 
2084 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
2085 	    &ioat->version, 0, "HW version (0xMM form)");
2086 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
2087 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
2088 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "intrdelay_supported", CTLFLAG_RD,
2089 	    &ioat->intrdelay_supported, 0, "Is INTRDELAY supported");
2090 	SYSCTL_ADD_U16(ctx, par, OID_AUTO, "intrdelay_max", CTLFLAG_RD,
2091 	    &ioat->intrdelay_max, 0,
2092 	    "Maximum configurable INTRDELAY on this channel (microseconds)");
2093 
2094 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "state", CTLFLAG_RD, NULL,
2095 	    "IOAT channel internal state");
2096 	state = SYSCTL_CHILDREN(tmp);
2097 
2098 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "ring_size_order", CTLFLAG_RD,
2099 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
2100 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "head", CTLFLAG_RD, &ioat->head,
2101 	    0, "SW descriptor head pointer index");
2102 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail,
2103 	    0, "SW descriptor tail pointer index");
2104 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "hw_head", CTLFLAG_RD,
2105 	    &ioat->hw_head, 0, "HW DMACOUNT");
2106 
2107 	SYSCTL_ADD_UQUAD(ctx, state, OID_AUTO, "last_completion", CTLFLAG_RD,
2108 	    ioat->comp_update, "HW addr of last completion");
2109 
2110 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_resize_pending", CTLFLAG_RD,
2111 	    &ioat->is_resize_pending, 0, "resize pending");
2112 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_submitter_processing",
2113 	    CTLFLAG_RD, &ioat->is_submitter_processing, 0,
2114 	    "submitter processing");
2115 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_completion_pending",
2116 	    CTLFLAG_RD, &ioat->is_completion_pending, 0, "completion pending");
2117 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_reset_pending", CTLFLAG_RD,
2118 	    &ioat->is_reset_pending, 0, "reset pending");
2119 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_channel_running", CTLFLAG_RD,
2120 	    &ioat->is_channel_running, 0, "channel running");
2121 
2122 	SYSCTL_ADD_PROC(ctx, state, OID_AUTO, "chansts",
2123 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
2124 	    "String of the channel status");
2125 
2126 	SYSCTL_ADD_U16(ctx, state, OID_AUTO, "intrdelay", CTLFLAG_RD,
2127 	    &ioat->cached_intrdelay, 0,
2128 	    "Current INTRDELAY on this channel (cached, microseconds)");
2129 
2130 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "hammer", CTLFLAG_RD, NULL,
2131 	    "Big hammers (mostly for testing)");
2132 	hammer = SYSCTL_CHILDREN(tmp);
2133 
2134 	SYSCTL_ADD_PROC(ctx, hammer, OID_AUTO, "force_hw_reset",
2135 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
2136 	    "Set to non-zero to reset the hardware");
2137 
2138 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "stats", CTLFLAG_RD, NULL,
2139 	    "IOAT channel statistics");
2140 	statpar = SYSCTL_CHILDREN(tmp);
2141 
2142 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "interrupts", CTLFLAG_RW,
2143 	    &ioat->stats.interrupts,
2144 	    "Number of interrupts processed on this channel");
2145 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "descriptors", CTLFLAG_RW,
2146 	    &ioat->stats.descriptors_processed,
2147 	    "Number of descriptors processed on this channel");
2148 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "submitted", CTLFLAG_RW,
2149 	    &ioat->stats.descriptors_submitted,
2150 	    "Number of descriptors submitted to this channel");
2151 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "errored", CTLFLAG_RW,
2152 	    &ioat->stats.descriptors_error,
2153 	    "Number of descriptors failed by channel errors");
2154 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "halts", CTLFLAG_RW,
2155 	    &ioat->stats.channel_halts, 0,
2156 	    "Number of times the channel has halted");
2157 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "last_halt_chanerr", CTLFLAG_RW,
2158 	    &ioat->stats.last_halt_chanerr, 0,
2159 	    "The raw CHANERR when the channel was last halted");
2160 
2161 	SYSCTL_ADD_PROC(ctx, statpar, OID_AUTO, "desc_per_interrupt",
2162 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_dpi, "A",
2163 	    "Descriptors per interrupt");
2164 }
2165 
2166 static inline struct ioat_softc *
2167 ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
2168 {
2169 	uint32_t old;
2170 
2171 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
2172 
2173 	old = atomic_fetchadd_32(&ioat->refcnt, 1);
2174 	KASSERT(old < UINT32_MAX, ("refcnt overflow"));
2175 
2176 #ifdef INVARIANTS
2177 	old = atomic_fetchadd_32(&ioat->refkinds[kind], 1);
2178 	KASSERT(old < UINT32_MAX, ("refcnt kind overflow"));
2179 #endif
2180 
2181 	return (ioat);
2182 }
2183 
2184 static inline void
2185 ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
2186 {
2187 
2188 	_ioat_putn(ioat, n, kind, FALSE);
2189 }
2190 
2191 static inline void
2192 ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
2193 {
2194 
2195 	_ioat_putn(ioat, n, kind, TRUE);
2196 }
2197 
2198 static inline void
2199 _ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
2200     boolean_t locked)
2201 {
2202 	uint32_t old;
2203 
2204 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
2205 
2206 	if (n == 0)
2207 		return;
2208 
2209 #ifdef INVARIANTS
2210 	old = atomic_fetchadd_32(&ioat->refkinds[kind], -n);
2211 	KASSERT(old >= n, ("refcnt kind underflow"));
2212 #endif
2213 
2214 	/* Skip acquiring the lock if resulting refcnt > 0. */
2215 	for (;;) {
2216 		old = ioat->refcnt;
2217 		if (old <= n)
2218 			break;
2219 		if (atomic_cmpset_32(&ioat->refcnt, old, old - n))
2220 			return;
2221 	}
2222 
2223 	if (locked)
2224 		mtx_assert(IOAT_REFLK, MA_OWNED);
2225 	else
2226 		mtx_lock(IOAT_REFLK);
2227 
2228 	old = atomic_fetchadd_32(&ioat->refcnt, -n);
2229 	KASSERT(old >= n, ("refcnt error"));
2230 
2231 	if (old == n)
2232 		wakeup(IOAT_REFLK);
2233 	if (!locked)
2234 		mtx_unlock(IOAT_REFLK);
2235 }
2236 
2237 static inline void
2238 ioat_put(struct ioat_softc *ioat, enum ioat_ref_kind kind)
2239 {
2240 
2241 	ioat_putn(ioat, 1, kind);
2242 }
2243 
2244 static void
2245 ioat_drain_locked(struct ioat_softc *ioat)
2246 {
2247 
2248 	mtx_assert(IOAT_REFLK, MA_OWNED);
2249 	while (ioat->refcnt > 0)
2250 		msleep(IOAT_REFLK, IOAT_REFLK, 0, "ioat_drain", 0);
2251 }
2252 
2253 #ifdef DDB
2254 #define	_db_show_lock(lo)	LOCK_CLASS(lo)->lc_ddb_show(lo)
2255 #define	db_show_lock(lk)	_db_show_lock(&(lk)->lock_object)
2256 DB_SHOW_COMMAND(ioat, db_show_ioat)
2257 {
2258 	struct ioat_softc *sc;
2259 	unsigned idx;
2260 
2261 	if (!have_addr)
2262 		goto usage;
2263 	idx = (unsigned)addr;
2264 	if (idx >= ioat_channel_index)
2265 		goto usage;
2266 
2267 	sc = ioat_channel[idx];
2268 	db_printf("ioat softc at %p\n", sc);
2269 	if (sc == NULL)
2270 		return;
2271 
2272 	db_printf(" version: %d\n", sc->version);
2273 	db_printf(" chan_idx: %u\n", sc->chan_idx);
2274 	db_printf(" submit_lock: ");
2275 	db_show_lock(&sc->submit_lock);
2276 
2277 	db_printf(" capabilities: %b\n", (int)sc->capabilities,
2278 	    IOAT_DMACAP_STR);
2279 	db_printf(" cached_intrdelay: %u\n", sc->cached_intrdelay);
2280 	db_printf(" *comp_update: 0x%jx\n", (uintmax_t)*sc->comp_update);
2281 
2282 	db_printf(" poll_timer:\n");
2283 	db_printf("  c_time: %ju\n", (uintmax_t)sc->poll_timer.c_time);
2284 	db_printf("  c_arg: %p\n", sc->poll_timer.c_arg);
2285 	db_printf("  c_func: %p\n", sc->poll_timer.c_func);
2286 	db_printf("  c_lock: %p\n", sc->poll_timer.c_lock);
2287 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->poll_timer.c_flags);
2288 
2289 	db_printf(" shrink_timer:\n");
2290 	db_printf("  c_time: %ju\n", (uintmax_t)sc->shrink_timer.c_time);
2291 	db_printf("  c_arg: %p\n", sc->shrink_timer.c_arg);
2292 	db_printf("  c_func: %p\n", sc->shrink_timer.c_func);
2293 	db_printf("  c_lock: %p\n", sc->shrink_timer.c_lock);
2294 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->shrink_timer.c_flags);
2295 
2296 	db_printf(" quiescing: %d\n", (int)sc->quiescing);
2297 	db_printf(" destroying: %d\n", (int)sc->destroying);
2298 	db_printf(" is_resize_pending: %d\n", (int)sc->is_resize_pending);
2299 	db_printf(" is_submitter_processing: %d\n",
2300 	    (int)sc->is_submitter_processing);
2301 	db_printf(" is_completion_pending: %d\n", (int)sc->is_completion_pending);
2302 	db_printf(" is_reset_pending: %d\n", (int)sc->is_reset_pending);
2303 	db_printf(" is_channel_running: %d\n", (int)sc->is_channel_running);
2304 	db_printf(" intrdelay_supported: %d\n", (int)sc->intrdelay_supported);
2305 	db_printf(" resetting: %d\n", (int)sc->resetting);
2306 
2307 	db_printf(" head: %u\n", sc->head);
2308 	db_printf(" tail: %u\n", sc->tail);
2309 	db_printf(" hw_head: %u\n", sc->hw_head);
2310 	db_printf(" ring_size_order: %u\n", sc->ring_size_order);
2311 	db_printf(" last_seen: 0x%lx\n", sc->last_seen);
2312 	db_printf(" ring: %p\n", sc->ring);
2313 
2314 	db_printf("  ring[%u] (tail):\n", sc->tail %
2315 	    (1 << sc->ring_size_order));
2316 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->tail)->id);
2317 	db_printf("   addr: 0x%lx\n",
2318 	    ioat_get_ring_entry(sc, sc->tail)->hw_desc_bus_addr);
2319 	db_printf("   next: 0x%lx\n",
2320 	    ioat_get_ring_entry(sc, sc->tail)->u.generic->next);
2321 
2322 	db_printf("  ring[%u] (head - 1):\n", (sc->head - 1) %
2323 	    (1 << sc->ring_size_order));
2324 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head - 1)->id);
2325 	db_printf("   addr: 0x%lx\n",
2326 	    ioat_get_ring_entry(sc, sc->head - 1)->hw_desc_bus_addr);
2327 	db_printf("   next: 0x%lx\n",
2328 	    ioat_get_ring_entry(sc, sc->head - 1)->u.generic->next);
2329 
2330 	db_printf("  ring[%u] (head):\n", (sc->head) %
2331 	    (1 << sc->ring_size_order));
2332 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head)->id);
2333 	db_printf("   addr: 0x%lx\n",
2334 	    ioat_get_ring_entry(sc, sc->head)->hw_desc_bus_addr);
2335 	db_printf("   next: 0x%lx\n",
2336 	    ioat_get_ring_entry(sc, sc->head)->u.generic->next);
2337 
2338 	for (idx = 0; idx < (1 << sc->ring_size_order); idx++)
2339 		if ((*sc->comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK)
2340 		    == ioat_get_ring_entry(sc, idx)->hw_desc_bus_addr)
2341 			db_printf("  ring[%u] == hardware tail\n", idx);
2342 
2343 	db_printf(" cleanup_lock: ");
2344 	db_show_lock(&sc->cleanup_lock);
2345 
2346 	db_printf(" refcnt: %u\n", sc->refcnt);
2347 #ifdef INVARIANTS
2348 	CTASSERT(IOAT_NUM_REF_KINDS == 2);
2349 	db_printf(" refkinds: [ENG=%u, DESCR=%u]\n", sc->refkinds[0],
2350 	    sc->refkinds[1]);
2351 #endif
2352 	db_printf(" stats:\n");
2353 	db_printf("  interrupts: %lu\n", sc->stats.interrupts);
2354 	db_printf("  descriptors_processed: %lu\n", sc->stats.descriptors_processed);
2355 	db_printf("  descriptors_error: %lu\n", sc->stats.descriptors_error);
2356 	db_printf("  descriptors_submitted: %lu\n", sc->stats.descriptors_submitted);
2357 
2358 	db_printf("  channel_halts: %u\n", sc->stats.channel_halts);
2359 	db_printf("  last_halt_chanerr: %u\n", sc->stats.last_halt_chanerr);
2360 
2361 	if (db_pager_quit)
2362 		return;
2363 
2364 	db_printf(" hw status:\n");
2365 	db_printf("  status: 0x%lx\n", ioat_get_chansts(sc));
2366 	db_printf("  chanctrl: 0x%x\n",
2367 	    (unsigned)ioat_read_2(sc, IOAT_CHANCTRL_OFFSET));
2368 	db_printf("  chancmd: 0x%x\n",
2369 	    (unsigned)ioat_read_1(sc, IOAT_CHANCMD_OFFSET));
2370 	db_printf("  dmacount: 0x%x\n",
2371 	    (unsigned)ioat_read_2(sc, IOAT_DMACOUNT_OFFSET));
2372 	db_printf("  chainaddr: 0x%lx\n",
2373 	    ioat_read_double_4(sc, IOAT_CHAINADDR_OFFSET_LOW));
2374 	db_printf("  chancmp: 0x%lx\n",
2375 	    ioat_read_double_4(sc, IOAT_CHANCMP_OFFSET_LOW));
2376 	db_printf("  chanerr: %b\n",
2377 	    (int)ioat_read_4(sc, IOAT_CHANERR_OFFSET), IOAT_CHANERR_STR);
2378 	return;
2379 usage:
2380 	db_printf("usage: show ioat <0-%u>\n", ioat_channel_index);
2381 	return;
2382 }
2383 #endif /* DDB */
2384