xref: /freebsd/sys/dev/ioat/ioat.c (revision d786719d90df3240f8f893dd8e19edd46f4273ee)
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/fail.h>
37 #include <sys/ioccom.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/rman.h>
44 #include <sys/sbuf.h>
45 #include <sys/sysctl.h>
46 #include <sys/taskqueue.h>
47 #include <sys/time.h>
48 #include <dev/pci/pcireg.h>
49 #include <dev/pci/pcivar.h>
50 #include <machine/bus.h>
51 #include <machine/resource.h>
52 #include <machine/stdarg.h>
53 
54 #ifdef DDB
55 #include <ddb/ddb.h>
56 #endif
57 
58 #include "ioat.h"
59 #include "ioat_hw.h"
60 #include "ioat_internal.h"
61 
62 #ifndef	BUS_SPACE_MAXADDR_40BIT
63 #define	BUS_SPACE_MAXADDR_40BIT	0xFFFFFFFFFFULL
64 #endif
65 #define	IOAT_REFLK	(&ioat->submit_lock)
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 int ioat_reserve_space(struct ioat_softc *, uint32_t, int mflags);
86 static union ioat_hw_descriptor *ioat_get_descriptor(struct ioat_softc *,
87     uint32_t index);
88 static struct ioat_descriptor *ioat_get_ring_entry(struct ioat_softc *,
89     uint32_t index);
90 static void ioat_halted_debug(struct ioat_softc *, uint32_t);
91 static void ioat_poll_timer_callback(void *arg);
92 static void dump_descriptor(void *hw_desc);
93 static void ioat_submit_single(struct ioat_softc *ioat);
94 static void ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg,
95     int error);
96 static int ioat_reset_hw(struct ioat_softc *ioat);
97 static void ioat_reset_hw_task(void *, int);
98 static void ioat_setup_sysctl(device_t device);
99 static int sysctl_handle_reset(SYSCTL_HANDLER_ARGS);
100 static inline struct ioat_softc *ioat_get(struct ioat_softc *,
101     enum ioat_ref_kind);
102 static inline void ioat_put(struct ioat_softc *, enum ioat_ref_kind);
103 static inline void _ioat_putn(struct ioat_softc *, uint32_t,
104     enum ioat_ref_kind, boolean_t);
105 static inline void ioat_putn(struct ioat_softc *, uint32_t,
106     enum ioat_ref_kind);
107 static inline void ioat_putn_locked(struct ioat_softc *, uint32_t,
108     enum ioat_ref_kind);
109 static void ioat_drain_locked(struct ioat_softc *);
110 
111 #define	ioat_log_message(v, ...) do {					\
112 	if ((v) <= g_ioat_debug_level) {				\
113 		device_printf(ioat->device, __VA_ARGS__);		\
114 	}								\
115 } while (0)
116 
117 MALLOC_DEFINE(M_IOAT, "ioat", "ioat driver memory allocations");
118 SYSCTL_NODE(_hw, OID_AUTO, ioat, CTLFLAG_RD, 0, "ioat node");
119 
120 static int g_force_legacy_interrupts;
121 SYSCTL_INT(_hw_ioat, OID_AUTO, force_legacy_interrupts, CTLFLAG_RDTUN,
122     &g_force_legacy_interrupts, 0, "Set to non-zero to force MSI-X disabled");
123 
124 int g_ioat_debug_level = 0;
125 SYSCTL_INT(_hw_ioat, OID_AUTO, debug_level, CTLFLAG_RWTUN, &g_ioat_debug_level,
126     0, "Set log level (0-3) for ioat(4). Higher is more verbose.");
127 
128 unsigned g_ioat_ring_order = 13;
129 SYSCTL_UINT(_hw_ioat, OID_AUTO, ring_order, CTLFLAG_RDTUN, &g_ioat_ring_order,
130     0, "Set IOAT ring order.  (1 << this) == ring size.");
131 
132 /*
133  * OS <-> Driver interface structures
134  */
135 static device_method_t ioat_pci_methods[] = {
136 	/* Device interface */
137 	DEVMETHOD(device_probe,     ioat_probe),
138 	DEVMETHOD(device_attach,    ioat_attach),
139 	DEVMETHOD(device_detach,    ioat_detach),
140 	DEVMETHOD_END
141 };
142 
143 static driver_t ioat_pci_driver = {
144 	"ioat",
145 	ioat_pci_methods,
146 	sizeof(struct ioat_softc),
147 };
148 
149 static devclass_t ioat_devclass;
150 DRIVER_MODULE(ioat, pci, ioat_pci_driver, ioat_devclass, 0, 0);
151 MODULE_VERSION(ioat, 1);
152 
153 /*
154  * Private data structures
155  */
156 static struct ioat_softc *ioat_channel[IOAT_MAX_CHANNELS];
157 static unsigned ioat_channel_index = 0;
158 SYSCTL_UINT(_hw_ioat, OID_AUTO, channels, CTLFLAG_RD, &ioat_channel_index, 0,
159     "Number of IOAT channels attached");
160 
161 static struct _pcsid
162 {
163 	u_int32_t   type;
164 	const char  *desc;
165 } pci_ids[] = {
166 	{ 0x34308086, "TBG IOAT Ch0" },
167 	{ 0x34318086, "TBG IOAT Ch1" },
168 	{ 0x34328086, "TBG IOAT Ch2" },
169 	{ 0x34338086, "TBG IOAT Ch3" },
170 	{ 0x34298086, "TBG IOAT Ch4" },
171 	{ 0x342a8086, "TBG IOAT Ch5" },
172 	{ 0x342b8086, "TBG IOAT Ch6" },
173 	{ 0x342c8086, "TBG IOAT Ch7" },
174 
175 	{ 0x37108086, "JSF IOAT Ch0" },
176 	{ 0x37118086, "JSF IOAT Ch1" },
177 	{ 0x37128086, "JSF IOAT Ch2" },
178 	{ 0x37138086, "JSF IOAT Ch3" },
179 	{ 0x37148086, "JSF IOAT Ch4" },
180 	{ 0x37158086, "JSF IOAT Ch5" },
181 	{ 0x37168086, "JSF IOAT Ch6" },
182 	{ 0x37178086, "JSF IOAT Ch7" },
183 	{ 0x37188086, "JSF IOAT Ch0 (RAID)" },
184 	{ 0x37198086, "JSF IOAT Ch1 (RAID)" },
185 
186 	{ 0x3c208086, "SNB IOAT Ch0" },
187 	{ 0x3c218086, "SNB IOAT Ch1" },
188 	{ 0x3c228086, "SNB IOAT Ch2" },
189 	{ 0x3c238086, "SNB IOAT Ch3" },
190 	{ 0x3c248086, "SNB IOAT Ch4" },
191 	{ 0x3c258086, "SNB IOAT Ch5" },
192 	{ 0x3c268086, "SNB IOAT Ch6" },
193 	{ 0x3c278086, "SNB IOAT Ch7" },
194 	{ 0x3c2e8086, "SNB IOAT Ch0 (RAID)" },
195 	{ 0x3c2f8086, "SNB IOAT Ch1 (RAID)" },
196 
197 	{ 0x0e208086, "IVB IOAT Ch0" },
198 	{ 0x0e218086, "IVB IOAT Ch1" },
199 	{ 0x0e228086, "IVB IOAT Ch2" },
200 	{ 0x0e238086, "IVB IOAT Ch3" },
201 	{ 0x0e248086, "IVB IOAT Ch4" },
202 	{ 0x0e258086, "IVB IOAT Ch5" },
203 	{ 0x0e268086, "IVB IOAT Ch6" },
204 	{ 0x0e278086, "IVB IOAT Ch7" },
205 	{ 0x0e2e8086, "IVB IOAT Ch0 (RAID)" },
206 	{ 0x0e2f8086, "IVB IOAT Ch1 (RAID)" },
207 
208 	{ 0x2f208086, "HSW IOAT Ch0" },
209 	{ 0x2f218086, "HSW IOAT Ch1" },
210 	{ 0x2f228086, "HSW IOAT Ch2" },
211 	{ 0x2f238086, "HSW IOAT Ch3" },
212 	{ 0x2f248086, "HSW IOAT Ch4" },
213 	{ 0x2f258086, "HSW IOAT Ch5" },
214 	{ 0x2f268086, "HSW IOAT Ch6" },
215 	{ 0x2f278086, "HSW IOAT Ch7" },
216 	{ 0x2f2e8086, "HSW IOAT Ch0 (RAID)" },
217 	{ 0x2f2f8086, "HSW IOAT Ch1 (RAID)" },
218 
219 	{ 0x0c508086, "BWD IOAT Ch0" },
220 	{ 0x0c518086, "BWD IOAT Ch1" },
221 	{ 0x0c528086, "BWD IOAT Ch2" },
222 	{ 0x0c538086, "BWD IOAT Ch3" },
223 
224 	{ 0x6f508086, "BDXDE IOAT Ch0" },
225 	{ 0x6f518086, "BDXDE IOAT Ch1" },
226 	{ 0x6f528086, "BDXDE IOAT Ch2" },
227 	{ 0x6f538086, "BDXDE IOAT Ch3" },
228 
229 	{ 0x6f208086, "BDX IOAT Ch0" },
230 	{ 0x6f218086, "BDX IOAT Ch1" },
231 	{ 0x6f228086, "BDX IOAT Ch2" },
232 	{ 0x6f238086, "BDX IOAT Ch3" },
233 	{ 0x6f248086, "BDX IOAT Ch4" },
234 	{ 0x6f258086, "BDX IOAT Ch5" },
235 	{ 0x6f268086, "BDX IOAT Ch6" },
236 	{ 0x6f278086, "BDX IOAT Ch7" },
237 	{ 0x6f2e8086, "BDX IOAT Ch0 (RAID)" },
238 	{ 0x6f2f8086, "BDX IOAT Ch1 (RAID)" },
239 
240 	{ 0x00000000, NULL           }
241 };
242 
243 /*
244  * OS <-> Driver linkage functions
245  */
246 static int
247 ioat_probe(device_t device)
248 {
249 	struct _pcsid *ep;
250 	u_int32_t type;
251 
252 	type = pci_get_devid(device);
253 	for (ep = pci_ids; ep->type; ep++) {
254 		if (ep->type == type) {
255 			device_set_desc(device, ep->desc);
256 			return (0);
257 		}
258 	}
259 	return (ENXIO);
260 }
261 
262 static int
263 ioat_attach(device_t device)
264 {
265 	struct ioat_softc *ioat;
266 	int error;
267 
268 	ioat = DEVICE2SOFTC(device);
269 	ioat->device = device;
270 
271 	error = ioat_map_pci_bar(ioat);
272 	if (error != 0)
273 		goto err;
274 
275 	ioat->version = ioat_read_cbver(ioat);
276 	if (ioat->version < IOAT_VER_3_0) {
277 		error = ENODEV;
278 		goto err;
279 	}
280 
281 	error = ioat3_attach(device);
282 	if (error != 0)
283 		goto err;
284 
285 	error = pci_enable_busmaster(device);
286 	if (error != 0)
287 		goto err;
288 
289 	error = ioat_setup_intr(ioat);
290 	if (error != 0)
291 		goto err;
292 
293 	error = ioat_reset_hw(ioat);
294 	if (error != 0)
295 		goto err;
296 
297 	ioat_process_events(ioat);
298 	ioat_setup_sysctl(device);
299 
300 	ioat->chan_idx = ioat_channel_index;
301 	ioat_channel[ioat_channel_index++] = ioat;
302 	ioat_test_attach();
303 
304 err:
305 	if (error != 0)
306 		ioat_detach(device);
307 	return (error);
308 }
309 
310 static int
311 ioat_detach(device_t device)
312 {
313 	struct ioat_softc *ioat;
314 
315 	ioat = DEVICE2SOFTC(device);
316 
317 	ioat_test_detach();
318 	taskqueue_drain(taskqueue_thread, &ioat->reset_task);
319 
320 	mtx_lock(IOAT_REFLK);
321 	ioat->quiescing = TRUE;
322 	ioat->destroying = TRUE;
323 	wakeup(&ioat->quiescing);
324 	wakeup(&ioat->resetting);
325 
326 	ioat_channel[ioat->chan_idx] = NULL;
327 
328 	ioat_drain_locked(ioat);
329 	mtx_unlock(IOAT_REFLK);
330 
331 	ioat_teardown_intr(ioat);
332 	callout_drain(&ioat->poll_timer);
333 
334 	pci_disable_busmaster(device);
335 
336 	if (ioat->pci_resource != NULL)
337 		bus_release_resource(device, SYS_RES_MEMORY,
338 		    ioat->pci_resource_id, ioat->pci_resource);
339 
340 	if (ioat->ring != NULL)
341 		ioat_free_ring(ioat, 1 << ioat->ring_size_order, ioat->ring);
342 
343 	if (ioat->comp_update != NULL) {
344 		bus_dmamap_unload(ioat->comp_update_tag, ioat->comp_update_map);
345 		bus_dmamem_free(ioat->comp_update_tag, ioat->comp_update,
346 		    ioat->comp_update_map);
347 		bus_dma_tag_destroy(ioat->comp_update_tag);
348 	}
349 
350 	if (ioat->hw_desc_ring != NULL) {
351 		bus_dmamap_unload(ioat->hw_desc_tag, ioat->hw_desc_map);
352 		bus_dmamem_free(ioat->hw_desc_tag, ioat->hw_desc_ring,
353 		    ioat->hw_desc_map);
354 		bus_dma_tag_destroy(ioat->hw_desc_tag);
355 	}
356 
357 	return (0);
358 }
359 
360 static int
361 ioat_teardown_intr(struct ioat_softc *ioat)
362 {
363 
364 	if (ioat->tag != NULL)
365 		bus_teardown_intr(ioat->device, ioat->res, ioat->tag);
366 
367 	if (ioat->res != NULL)
368 		bus_release_resource(ioat->device, SYS_RES_IRQ,
369 		    rman_get_rid(ioat->res), ioat->res);
370 
371 	pci_release_msi(ioat->device);
372 	return (0);
373 }
374 
375 static int
376 ioat_start_channel(struct ioat_softc *ioat)
377 {
378 	struct ioat_dma_hw_descriptor *hw_desc;
379 	struct ioat_descriptor *desc;
380 	struct bus_dmadesc *dmadesc;
381 	uint64_t status;
382 	uint32_t chanerr;
383 	int i;
384 
385 	ioat_acquire(&ioat->dmaengine);
386 
387 	/* Submit 'NULL' operation manually to avoid quiescing flag */
388 	desc = ioat_get_ring_entry(ioat, ioat->head);
389 	hw_desc = &ioat_get_descriptor(ioat, ioat->head)->dma;
390 	dmadesc = &desc->bus_dmadesc;
391 
392 	dmadesc->callback_fn = NULL;
393 	dmadesc->callback_arg = NULL;
394 
395 	hw_desc->u.control_raw = 0;
396 	hw_desc->u.control_generic.op = IOAT_OP_COPY;
397 	hw_desc->u.control_generic.completion_update = 1;
398 	hw_desc->size = 8;
399 	hw_desc->src_addr = 0;
400 	hw_desc->dest_addr = 0;
401 	hw_desc->u.control.null = 1;
402 
403 	ioat_submit_single(ioat);
404 	ioat_release(&ioat->dmaengine);
405 
406 	for (i = 0; i < 100; i++) {
407 		DELAY(1);
408 		status = ioat_get_chansts(ioat);
409 		if (is_ioat_idle(status))
410 			return (0);
411 	}
412 
413 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
414 	ioat_log_message(0, "could not start channel: "
415 	    "status = %#jx error = %b\n", (uintmax_t)status, (int)chanerr,
416 	    IOAT_CHANERR_STR);
417 	return (ENXIO);
418 }
419 
420 /*
421  * Initialize Hardware
422  */
423 static int
424 ioat3_attach(device_t device)
425 {
426 	struct ioat_softc *ioat;
427 	struct ioat_descriptor *ring;
428 	struct ioat_dma_hw_descriptor *dma_hw_desc;
429 	void *hw_desc;
430 	size_t ringsz;
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 	TASK_INIT(&ioat->reset_task, 0, ioat_reset_hw_task, ioat);
456 
457 	/* Establish lock order for Witness */
458 	mtx_lock(&ioat->submit_lock);
459 	mtx_lock(&ioat->cleanup_lock);
460 	mtx_unlock(&ioat->cleanup_lock);
461 	mtx_unlock(&ioat->submit_lock);
462 
463 	ioat->is_submitter_processing = FALSE;
464 	ioat->is_completion_pending = FALSE;
465 	ioat->is_reset_pending = FALSE;
466 	ioat->is_channel_running = FALSE;
467 
468 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), sizeof(uint64_t), 0x0,
469 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
470 	    sizeof(uint64_t), 1, sizeof(uint64_t), 0, NULL, NULL,
471 	    &ioat->comp_update_tag);
472 
473 	error = bus_dmamem_alloc(ioat->comp_update_tag,
474 	    (void **)&ioat->comp_update, BUS_DMA_ZERO, &ioat->comp_update_map);
475 	if (ioat->comp_update == NULL)
476 		return (ENOMEM);
477 
478 	error = bus_dmamap_load(ioat->comp_update_tag, ioat->comp_update_map,
479 	    ioat->comp_update, sizeof(uint64_t), ioat_comp_update_map, ioat,
480 	    0);
481 	if (error != 0)
482 		return (error);
483 
484 	ioat->ring_size_order = g_ioat_ring_order;
485 	num_descriptors = 1 << ioat->ring_size_order;
486 	ringsz = sizeof(struct ioat_dma_hw_descriptor) * num_descriptors;
487 
488 	error = bus_dma_tag_create(bus_get_dma_tag(ioat->device),
489 	    2 * 1024 * 1024, 0x0, (bus_addr_t)BUS_SPACE_MAXADDR_40BIT,
490 	    BUS_SPACE_MAXADDR, NULL, NULL, ringsz, 1, ringsz, 0, NULL, NULL,
491 	    &ioat->hw_desc_tag);
492 	if (error != 0)
493 		return (error);
494 
495 	error = bus_dmamem_alloc(ioat->hw_desc_tag, &hw_desc,
496 	    BUS_DMA_ZERO | BUS_DMA_WAITOK, &ioat->hw_desc_map);
497 	if (error != 0)
498 		return (error);
499 
500 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
501 	    ringsz, ioat_dmamap_cb, &ioat->hw_desc_bus_addr, BUS_DMA_WAITOK);
502 	if (error)
503 		return (error);
504 
505 	ioat->hw_desc_ring = hw_desc;
506 
507 	ioat->ring = malloc(num_descriptors * sizeof(*ring), M_IOAT,
508 	    M_ZERO | M_WAITOK);
509 
510 	ring = ioat->ring;
511 	for (i = 0; i < num_descriptors; i++) {
512 		memset(&ring[i].bus_dmadesc, 0, sizeof(ring[i].bus_dmadesc));
513 		ring[i].id = i;
514 	}
515 
516 	for (i = 0; i < num_descriptors; i++) {
517 		dma_hw_desc = &ioat->hw_desc_ring[i].dma;
518 		dma_hw_desc->next = RING_PHYS_ADDR(ioat, i + 1);
519 	}
520 
521 	ioat->head = ioat->hw_head = 0;
522 	ioat->tail = 0;
523 	ioat->last_seen = 0;
524 	*ioat->comp_update = 0;
525 	return (0);
526 }
527 
528 static int
529 ioat_map_pci_bar(struct ioat_softc *ioat)
530 {
531 
532 	ioat->pci_resource_id = PCIR_BAR(0);
533 	ioat->pci_resource = bus_alloc_resource_any(ioat->device,
534 	    SYS_RES_MEMORY, &ioat->pci_resource_id, RF_ACTIVE);
535 
536 	if (ioat->pci_resource == NULL) {
537 		ioat_log_message(0, "unable to allocate pci resource\n");
538 		return (ENODEV);
539 	}
540 
541 	ioat->pci_bus_tag = rman_get_bustag(ioat->pci_resource);
542 	ioat->pci_bus_handle = rman_get_bushandle(ioat->pci_resource);
543 	return (0);
544 }
545 
546 static void
547 ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
548 {
549 	struct ioat_softc *ioat = arg;
550 
551 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
552 	ioat->comp_update_bus_addr = seg[0].ds_addr;
553 }
554 
555 static void
556 ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
557 {
558 	bus_addr_t *baddr;
559 
560 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
561 	baddr = arg;
562 	*baddr = segs->ds_addr;
563 }
564 
565 /*
566  * Interrupt setup and handlers
567  */
568 static int
569 ioat_setup_intr(struct ioat_softc *ioat)
570 {
571 	uint32_t num_vectors;
572 	int error;
573 	boolean_t use_msix;
574 	boolean_t force_legacy_interrupts;
575 
576 	use_msix = FALSE;
577 	force_legacy_interrupts = FALSE;
578 
579 	if (!g_force_legacy_interrupts && pci_msix_count(ioat->device) >= 1) {
580 		num_vectors = 1;
581 		pci_alloc_msix(ioat->device, &num_vectors);
582 		if (num_vectors == 1)
583 			use_msix = TRUE;
584 	}
585 
586 	if (use_msix) {
587 		ioat->rid = 1;
588 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
589 		    &ioat->rid, RF_ACTIVE);
590 	} else {
591 		ioat->rid = 0;
592 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
593 		    &ioat->rid, RF_SHAREABLE | RF_ACTIVE);
594 	}
595 	if (ioat->res == NULL) {
596 		ioat_log_message(0, "bus_alloc_resource failed\n");
597 		return (ENOMEM);
598 	}
599 
600 	ioat->tag = NULL;
601 	error = bus_setup_intr(ioat->device, ioat->res, INTR_MPSAFE |
602 	    INTR_TYPE_MISC, NULL, ioat_interrupt_handler, ioat, &ioat->tag);
603 	if (error != 0) {
604 		ioat_log_message(0, "bus_setup_intr failed\n");
605 		return (error);
606 	}
607 
608 	ioat_write_intrctrl(ioat, IOAT_INTRCTRL_MASTER_INT_EN);
609 	return (0);
610 }
611 
612 static boolean_t
613 ioat_model_resets_msix(struct ioat_softc *ioat)
614 {
615 	u_int32_t pciid;
616 
617 	pciid = pci_get_devid(ioat->device);
618 	switch (pciid) {
619 		/* BWD: */
620 	case 0x0c508086:
621 	case 0x0c518086:
622 	case 0x0c528086:
623 	case 0x0c538086:
624 		/* BDXDE: */
625 	case 0x6f508086:
626 	case 0x6f518086:
627 	case 0x6f528086:
628 	case 0x6f538086:
629 		return (TRUE);
630 	}
631 
632 	return (FALSE);
633 }
634 
635 static void
636 ioat_interrupt_handler(void *arg)
637 {
638 	struct ioat_softc *ioat = arg;
639 
640 	ioat->stats.interrupts++;
641 	ioat_process_events(ioat);
642 }
643 
644 static int
645 chanerr_to_errno(uint32_t chanerr)
646 {
647 
648 	if (chanerr == 0)
649 		return (0);
650 	if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
651 		return (EFAULT);
652 	if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
653 		return (EIO);
654 	/* This one is probably our fault: */
655 	if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
656 		return (EIO);
657 	return (EIO);
658 }
659 
660 static void
661 ioat_process_events(struct ioat_softc *ioat)
662 {
663 	struct ioat_descriptor *desc;
664 	struct bus_dmadesc *dmadesc;
665 	uint64_t comp_update, status;
666 	uint32_t completed, chanerr;
667 	boolean_t pending;
668 	int error;
669 
670 	mtx_lock(&ioat->cleanup_lock);
671 
672 	/*
673 	 * Don't run while the hardware is being reset.  Reset is responsible
674 	 * for blocking new work and draining & completing existing work, so
675 	 * there is nothing to do until new work is queued after reset anyway.
676 	 */
677 	if (ioat->resetting_cleanup) {
678 		mtx_unlock(&ioat->cleanup_lock);
679 		return;
680 	}
681 
682 	completed = 0;
683 	comp_update = *ioat->comp_update;
684 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
685 
686 	if (status < ioat->hw_desc_bus_addr ||
687 	    status >= ioat->hw_desc_bus_addr + (1 << ioat->ring_size_order) *
688 	    sizeof(struct ioat_generic_hw_descriptor))
689 		panic("Bogus completion address %jx (channel %u)",
690 		    (uintmax_t)status, ioat->chan_idx);
691 
692 	if (status == ioat->last_seen) {
693 		/*
694 		 * If we landed in process_events and nothing has been
695 		 * completed, check for a timeout due to channel halt.
696 		 */
697 		goto out;
698 	}
699 	CTR4(KTR_IOAT, "%s channel=%u hw_status=0x%lx last_seen=0x%lx",
700 	    __func__, ioat->chan_idx, comp_update, ioat->last_seen);
701 
702 	while (RING_PHYS_ADDR(ioat, ioat->tail - 1) != status) {
703 		desc = ioat_get_ring_entry(ioat, ioat->tail);
704 		dmadesc = &desc->bus_dmadesc;
705 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) ok  cb %p(%p)",
706 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
707 		    dmadesc->callback_arg);
708 
709 		if (dmadesc->callback_fn != NULL)
710 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
711 
712 		completed++;
713 		ioat->tail++;
714 	}
715 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
716 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
717 
718 	if (completed != 0) {
719 		ioat->last_seen = RING_PHYS_ADDR(ioat, ioat->tail - 1);
720 		ioat->stats.descriptors_processed += completed;
721 	}
722 
723 out:
724 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
725 
726 	/* Perform a racy check first; only take the locks if it passes. */
727 	pending = (ioat_get_active(ioat) != 0);
728 	if (!pending && ioat->is_completion_pending) {
729 		mtx_unlock(&ioat->cleanup_lock);
730 		mtx_lock(&ioat->submit_lock);
731 		mtx_lock(&ioat->cleanup_lock);
732 
733 		pending = (ioat_get_active(ioat) != 0);
734 		if (!pending && ioat->is_completion_pending) {
735 			ioat->is_completion_pending = FALSE;
736 			callout_stop(&ioat->poll_timer);
737 		}
738 		mtx_unlock(&ioat->submit_lock);
739 	}
740 	mtx_unlock(&ioat->cleanup_lock);
741 
742 	if (pending)
743 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
744 		    ioat);
745 
746 	if (completed != 0) {
747 		ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
748 		wakeup(&ioat->tail);
749 	}
750 
751 	/*
752 	 * The device doesn't seem to reliably push suspend/halt statuses to
753 	 * the channel completion memory address, so poll the device register
754 	 * here.
755 	 */
756 	comp_update = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
757 	if (!is_ioat_halted(comp_update) && !is_ioat_suspended(comp_update))
758 		return;
759 
760 	ioat->stats.channel_halts++;
761 
762 	/*
763 	 * Fatal programming error on this DMA channel.  Flush any outstanding
764 	 * work with error status and restart the engine.
765 	 */
766 	mtx_lock(&ioat->submit_lock);
767 	mtx_lock(&ioat->cleanup_lock);
768 	ioat->quiescing = TRUE;
769 	/*
770 	 * This is safe to do here because we have both locks and the submit
771 	 * queue is quiesced.  We know that we will drain all outstanding
772 	 * events, so ioat_reset_hw can't deadlock.  It is necessary to
773 	 * protect other ioat_process_event threads from racing ioat_reset_hw,
774 	 * reading an indeterminate hw state, and attempting to continue
775 	 * issuing completions.
776 	 */
777 	ioat->resetting_cleanup = TRUE;
778 
779 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
780 	if (1 <= g_ioat_debug_level)
781 		ioat_halted_debug(ioat, chanerr);
782 	ioat->stats.last_halt_chanerr = chanerr;
783 
784 	while (ioat_get_active(ioat) > 0) {
785 		desc = ioat_get_ring_entry(ioat, ioat->tail);
786 		dmadesc = &desc->bus_dmadesc;
787 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) err cb %p(%p)",
788 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
789 		    dmadesc->callback_arg);
790 
791 		if (dmadesc->callback_fn != NULL)
792 			dmadesc->callback_fn(dmadesc->callback_arg,
793 			    chanerr_to_errno(chanerr));
794 
795 		ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
796 		ioat->tail++;
797 		ioat->stats.descriptors_processed++;
798 		ioat->stats.descriptors_error++;
799 	}
800 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
801 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
802 
803 	if (ioat->is_completion_pending) {
804 		ioat->is_completion_pending = FALSE;
805 		callout_stop(&ioat->poll_timer);
806 	}
807 
808 	/* Clear error status */
809 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
810 
811 	mtx_unlock(&ioat->cleanup_lock);
812 	mtx_unlock(&ioat->submit_lock);
813 
814 	ioat_log_message(0, "Resetting channel to recover from error\n");
815 	error = taskqueue_enqueue(taskqueue_thread, &ioat->reset_task);
816 	KASSERT(error == 0,
817 	    ("%s: taskqueue_enqueue failed: %d", __func__, error));
818 }
819 
820 static void
821 ioat_reset_hw_task(void *ctx, int pending __unused)
822 {
823 	struct ioat_softc *ioat;
824 	int error;
825 
826 	ioat = ctx;
827 	ioat_log_message(1, "%s: Resetting channel\n", __func__);
828 
829 	error = ioat_reset_hw(ioat);
830 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
831 	(void)error;
832 }
833 
834 /*
835  * User API functions
836  */
837 unsigned
838 ioat_get_nchannels(void)
839 {
840 
841 	return (ioat_channel_index);
842 }
843 
844 bus_dmaengine_t
845 ioat_get_dmaengine(uint32_t index, int flags)
846 {
847 	struct ioat_softc *ioat;
848 
849 	KASSERT((flags & ~(M_NOWAIT | M_WAITOK)) == 0,
850 	    ("invalid flags: 0x%08x", flags));
851 	KASSERT((flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK),
852 	    ("invalid wait | nowait"));
853 
854 	if (index >= ioat_channel_index)
855 		return (NULL);
856 
857 	ioat = ioat_channel[index];
858 	if (ioat == NULL || ioat->destroying)
859 		return (NULL);
860 
861 	if (ioat->quiescing) {
862 		if ((flags & M_NOWAIT) != 0)
863 			return (NULL);
864 
865 		mtx_lock(IOAT_REFLK);
866 		while (ioat->quiescing && !ioat->destroying)
867 			msleep(&ioat->quiescing, IOAT_REFLK, 0, "getdma", 0);
868 		mtx_unlock(IOAT_REFLK);
869 
870 		if (ioat->destroying)
871 			return (NULL);
872 	}
873 
874 	/*
875 	 * There's a race here between the quiescing check and HW reset or
876 	 * module destroy.
877 	 */
878 	return (&ioat_get(ioat, IOAT_DMAENGINE_REF)->dmaengine);
879 }
880 
881 void
882 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
883 {
884 	struct ioat_softc *ioat;
885 
886 	ioat = to_ioat_softc(dmaengine);
887 	ioat_put(ioat, IOAT_DMAENGINE_REF);
888 }
889 
890 int
891 ioat_get_hwversion(bus_dmaengine_t dmaengine)
892 {
893 	struct ioat_softc *ioat;
894 
895 	ioat = to_ioat_softc(dmaengine);
896 	return (ioat->version);
897 }
898 
899 size_t
900 ioat_get_max_io_size(bus_dmaengine_t dmaengine)
901 {
902 	struct ioat_softc *ioat;
903 
904 	ioat = to_ioat_softc(dmaengine);
905 	return (ioat->max_xfer_size);
906 }
907 
908 uint32_t
909 ioat_get_capabilities(bus_dmaengine_t dmaengine)
910 {
911 	struct ioat_softc *ioat;
912 
913 	ioat = to_ioat_softc(dmaengine);
914 	return (ioat->capabilities);
915 }
916 
917 int
918 ioat_set_interrupt_coalesce(bus_dmaengine_t dmaengine, uint16_t delay)
919 {
920 	struct ioat_softc *ioat;
921 
922 	ioat = to_ioat_softc(dmaengine);
923 	if (!ioat->intrdelay_supported)
924 		return (ENODEV);
925 	if (delay > ioat->intrdelay_max)
926 		return (ERANGE);
927 
928 	ioat_write_2(ioat, IOAT_INTRDELAY_OFFSET, delay);
929 	ioat->cached_intrdelay =
930 	    ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) & IOAT_INTRDELAY_US_MASK;
931 	return (0);
932 }
933 
934 uint16_t
935 ioat_get_max_coalesce_period(bus_dmaengine_t dmaengine)
936 {
937 	struct ioat_softc *ioat;
938 
939 	ioat = to_ioat_softc(dmaengine);
940 	return (ioat->intrdelay_max);
941 }
942 
943 void
944 ioat_acquire(bus_dmaengine_t dmaengine)
945 {
946 	struct ioat_softc *ioat;
947 
948 	ioat = to_ioat_softc(dmaengine);
949 	mtx_lock(&ioat->submit_lock);
950 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
951 	ioat->acq_head = ioat->head;
952 }
953 
954 int
955 ioat_acquire_reserve(bus_dmaengine_t dmaengine, unsigned n, int mflags)
956 {
957 	struct ioat_softc *ioat;
958 	int error;
959 
960 	ioat = to_ioat_softc(dmaengine);
961 	ioat_acquire(dmaengine);
962 
963 	error = ioat_reserve_space(ioat, n, mflags);
964 	if (error != 0)
965 		ioat_release(dmaengine);
966 	return (error);
967 }
968 
969 void
970 ioat_release(bus_dmaengine_t dmaengine)
971 {
972 	struct ioat_softc *ioat;
973 
974 	ioat = to_ioat_softc(dmaengine);
975 	CTR4(KTR_IOAT, "%s channel=%u dispatch1 hw_head=%u head=%u", __func__,
976 	    ioat->chan_idx, ioat->hw_head & UINT16_MAX, ioat->head);
977 	KFAIL_POINT_CODE(DEBUG_FP, ioat_release, /* do nothing */);
978 	CTR4(KTR_IOAT, "%s channel=%u dispatch2 hw_head=%u head=%u", __func__,
979 	    ioat->chan_idx, ioat->hw_head & UINT16_MAX, ioat->head);
980 
981 	if (ioat->acq_head != ioat->head) {
982 		ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET,
983 		    (uint16_t)ioat->hw_head);
984 
985 		if (!ioat->is_completion_pending) {
986 			ioat->is_completion_pending = TRUE;
987 			callout_reset(&ioat->poll_timer, 1,
988 			    ioat_poll_timer_callback, ioat);
989 		}
990 	}
991 	mtx_unlock(&ioat->submit_lock);
992 }
993 
994 static struct ioat_descriptor *
995 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
996     uint32_t size, uint64_t src, uint64_t dst,
997     bus_dmaengine_callback_t callback_fn, void *callback_arg,
998     uint32_t flags)
999 {
1000 	struct ioat_generic_hw_descriptor *hw_desc;
1001 	struct ioat_descriptor *desc;
1002 	int mflags;
1003 
1004 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1005 
1006 	KASSERT((flags & ~_DMA_GENERIC_FLAGS) == 0,
1007 	    ("Unrecognized flag(s): %#x", flags & ~_DMA_GENERIC_FLAGS));
1008 	if ((flags & DMA_NO_WAIT) != 0)
1009 		mflags = M_NOWAIT;
1010 	else
1011 		mflags = M_WAITOK;
1012 
1013 	if (size > ioat->max_xfer_size) {
1014 		ioat_log_message(0, "%s: max_xfer_size = %d, requested = %u\n",
1015 		    __func__, ioat->max_xfer_size, (unsigned)size);
1016 		return (NULL);
1017 	}
1018 
1019 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
1020 		return (NULL);
1021 
1022 	desc = ioat_get_ring_entry(ioat, ioat->head);
1023 	hw_desc = &ioat_get_descriptor(ioat, ioat->head)->generic;
1024 
1025 	hw_desc->u.control_raw = 0;
1026 	hw_desc->u.control_generic.op = op;
1027 	hw_desc->u.control_generic.completion_update = 1;
1028 
1029 	if ((flags & DMA_INT_EN) != 0)
1030 		hw_desc->u.control_generic.int_enable = 1;
1031 	if ((flags & DMA_FENCE) != 0)
1032 		hw_desc->u.control_generic.fence = 1;
1033 
1034 	hw_desc->size = size;
1035 	hw_desc->src_addr = src;
1036 	hw_desc->dest_addr = dst;
1037 
1038 	desc->bus_dmadesc.callback_fn = callback_fn;
1039 	desc->bus_dmadesc.callback_arg = callback_arg;
1040 	return (desc);
1041 }
1042 
1043 struct bus_dmadesc *
1044 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
1045     void *callback_arg, uint32_t flags)
1046 {
1047 	struct ioat_dma_hw_descriptor *hw_desc;
1048 	struct ioat_descriptor *desc;
1049 	struct ioat_softc *ioat;
1050 
1051 	ioat = to_ioat_softc(dmaengine);
1052 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1053 
1054 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
1055 	    callback_arg, flags);
1056 	if (desc == NULL)
1057 		return (NULL);
1058 
1059 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1060 	hw_desc->u.control.null = 1;
1061 	ioat_submit_single(ioat);
1062 	return (&desc->bus_dmadesc);
1063 }
1064 
1065 struct bus_dmadesc *
1066 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
1067     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
1068     void *callback_arg, uint32_t flags)
1069 {
1070 	struct ioat_dma_hw_descriptor *hw_desc;
1071 	struct ioat_descriptor *desc;
1072 	struct ioat_softc *ioat;
1073 
1074 	ioat = to_ioat_softc(dmaengine);
1075 
1076 	if (((src | dst) & (0xffffull << 48)) != 0) {
1077 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1078 		    __func__);
1079 		return (NULL);
1080 	}
1081 
1082 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
1083 	    callback_arg, flags);
1084 	if (desc == NULL)
1085 		return (NULL);
1086 
1087 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1088 	if (g_ioat_debug_level >= 3)
1089 		dump_descriptor(hw_desc);
1090 
1091 	ioat_submit_single(ioat);
1092 	CTR6(KTR_IOAT, "%s channel=%u desc=%p dest=%lx src=%lx len=%lx",
1093 	    __func__, ioat->chan_idx, &desc->bus_dmadesc, dst, src, len);
1094 	return (&desc->bus_dmadesc);
1095 }
1096 
1097 struct bus_dmadesc *
1098 ioat_copy_8k_aligned(bus_dmaengine_t dmaengine, bus_addr_t dst1,
1099     bus_addr_t dst2, bus_addr_t src1, bus_addr_t src2,
1100     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1101 {
1102 	struct ioat_dma_hw_descriptor *hw_desc;
1103 	struct ioat_descriptor *desc;
1104 	struct ioat_softc *ioat;
1105 
1106 	ioat = to_ioat_softc(dmaengine);
1107 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1108 
1109 	if (((src1 | src2 | dst1 | dst2) & (0xffffull << 48)) != 0) {
1110 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1111 		    __func__);
1112 		return (NULL);
1113 	}
1114 	if (((src1 | src2 | dst1 | dst2) & PAGE_MASK) != 0) {
1115 		ioat_log_message(0, "%s: Addresses must be page-aligned\n",
1116 		    __func__);
1117 		return (NULL);
1118 	}
1119 
1120 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 2 * PAGE_SIZE, src1, dst1,
1121 	    callback_fn, callback_arg, flags);
1122 	if (desc == NULL)
1123 		return (NULL);
1124 
1125 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1126 	if (src2 != src1 + PAGE_SIZE) {
1127 		hw_desc->u.control.src_page_break = 1;
1128 		hw_desc->next_src_addr = src2;
1129 	}
1130 	if (dst2 != dst1 + PAGE_SIZE) {
1131 		hw_desc->u.control.dest_page_break = 1;
1132 		hw_desc->next_dest_addr = dst2;
1133 	}
1134 
1135 	if (g_ioat_debug_level >= 3)
1136 		dump_descriptor(hw_desc);
1137 
1138 	ioat_submit_single(ioat);
1139 	return (&desc->bus_dmadesc);
1140 }
1141 
1142 struct bus_dmadesc *
1143 ioat_copy_crc(bus_dmaengine_t dmaengine, bus_addr_t dst, bus_addr_t src,
1144     bus_size_t len, uint32_t *initialseed, bus_addr_t crcptr,
1145     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1146 {
1147 	struct ioat_crc32_hw_descriptor *hw_desc;
1148 	struct ioat_descriptor *desc;
1149 	struct ioat_softc *ioat;
1150 	uint32_t teststore;
1151 	uint8_t op;
1152 
1153 	ioat = to_ioat_softc(dmaengine);
1154 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1155 
1156 	if ((ioat->capabilities & IOAT_DMACAP_MOVECRC) == 0) {
1157 		ioat_log_message(0, "%s: Device lacks MOVECRC capability\n",
1158 		    __func__);
1159 		return (NULL);
1160 	}
1161 	if (((src | dst) & (0xffffffull << 40)) != 0) {
1162 		ioat_log_message(0, "%s: High 24 bits of src/dst invalid\n",
1163 		    __func__);
1164 		return (NULL);
1165 	}
1166 	teststore = (flags & _DMA_CRC_TESTSTORE);
1167 	if (teststore == _DMA_CRC_TESTSTORE) {
1168 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1169 		return (NULL);
1170 	}
1171 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1172 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1173 		    __func__);
1174 		return (NULL);
1175 	}
1176 
1177 	switch (teststore) {
1178 	case DMA_CRC_STORE:
1179 		op = IOAT_OP_MOVECRC_STORE;
1180 		break;
1181 	case DMA_CRC_TEST:
1182 		op = IOAT_OP_MOVECRC_TEST;
1183 		break;
1184 	default:
1185 		KASSERT(teststore == 0, ("bogus"));
1186 		op = IOAT_OP_MOVECRC;
1187 		break;
1188 	}
1189 
1190 	if ((flags & DMA_CRC_INLINE) == 0 &&
1191 	    (crcptr & (0xffffffull << 40)) != 0) {
1192 		ioat_log_message(0,
1193 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1194 		return (NULL);
1195 	}
1196 
1197 	desc = ioat_op_generic(ioat, op, len, src, dst, callback_fn,
1198 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1199 	if (desc == NULL)
1200 		return (NULL);
1201 
1202 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1203 
1204 	if ((flags & DMA_CRC_INLINE) == 0)
1205 		hw_desc->crc_address = crcptr;
1206 	else
1207 		hw_desc->u.control.crc_location = 1;
1208 
1209 	if (initialseed != NULL) {
1210 		hw_desc->u.control.use_seed = 1;
1211 		hw_desc->seed = *initialseed;
1212 	}
1213 
1214 	if (g_ioat_debug_level >= 3)
1215 		dump_descriptor(hw_desc);
1216 
1217 	ioat_submit_single(ioat);
1218 	return (&desc->bus_dmadesc);
1219 }
1220 
1221 struct bus_dmadesc *
1222 ioat_crc(bus_dmaengine_t dmaengine, bus_addr_t src, bus_size_t len,
1223     uint32_t *initialseed, bus_addr_t crcptr,
1224     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1225 {
1226 	struct ioat_crc32_hw_descriptor *hw_desc;
1227 	struct ioat_descriptor *desc;
1228 	struct ioat_softc *ioat;
1229 	uint32_t teststore;
1230 	uint8_t op;
1231 
1232 	ioat = to_ioat_softc(dmaengine);
1233 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1234 
1235 	if ((ioat->capabilities & IOAT_DMACAP_CRC) == 0) {
1236 		ioat_log_message(0, "%s: Device lacks CRC capability\n",
1237 		    __func__);
1238 		return (NULL);
1239 	}
1240 	if ((src & (0xffffffull << 40)) != 0) {
1241 		ioat_log_message(0, "%s: High 24 bits of src invalid\n",
1242 		    __func__);
1243 		return (NULL);
1244 	}
1245 	teststore = (flags & _DMA_CRC_TESTSTORE);
1246 	if (teststore == _DMA_CRC_TESTSTORE) {
1247 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1248 		return (NULL);
1249 	}
1250 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1251 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1252 		    __func__);
1253 		return (NULL);
1254 	}
1255 
1256 	switch (teststore) {
1257 	case DMA_CRC_STORE:
1258 		op = IOAT_OP_CRC_STORE;
1259 		break;
1260 	case DMA_CRC_TEST:
1261 		op = IOAT_OP_CRC_TEST;
1262 		break;
1263 	default:
1264 		KASSERT(teststore == 0, ("bogus"));
1265 		op = IOAT_OP_CRC;
1266 		break;
1267 	}
1268 
1269 	if ((flags & DMA_CRC_INLINE) == 0 &&
1270 	    (crcptr & (0xffffffull << 40)) != 0) {
1271 		ioat_log_message(0,
1272 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1273 		return (NULL);
1274 	}
1275 
1276 	desc = ioat_op_generic(ioat, op, len, src, 0, callback_fn,
1277 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1278 	if (desc == NULL)
1279 		return (NULL);
1280 
1281 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1282 
1283 	if ((flags & DMA_CRC_INLINE) == 0)
1284 		hw_desc->crc_address = crcptr;
1285 	else
1286 		hw_desc->u.control.crc_location = 1;
1287 
1288 	if (initialseed != NULL) {
1289 		hw_desc->u.control.use_seed = 1;
1290 		hw_desc->seed = *initialseed;
1291 	}
1292 
1293 	if (g_ioat_debug_level >= 3)
1294 		dump_descriptor(hw_desc);
1295 
1296 	ioat_submit_single(ioat);
1297 	return (&desc->bus_dmadesc);
1298 }
1299 
1300 struct bus_dmadesc *
1301 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
1302     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
1303     uint32_t flags)
1304 {
1305 	struct ioat_fill_hw_descriptor *hw_desc;
1306 	struct ioat_descriptor *desc;
1307 	struct ioat_softc *ioat;
1308 
1309 	ioat = to_ioat_softc(dmaengine);
1310 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1311 
1312 	if ((ioat->capabilities & IOAT_DMACAP_BFILL) == 0) {
1313 		ioat_log_message(0, "%s: Device lacks BFILL capability\n",
1314 		    __func__);
1315 		return (NULL);
1316 	}
1317 
1318 	if ((dst & (0xffffull << 48)) != 0) {
1319 		ioat_log_message(0, "%s: High 16 bits of dst invalid\n",
1320 		    __func__);
1321 		return (NULL);
1322 	}
1323 
1324 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, fillpattern, dst,
1325 	    callback_fn, callback_arg, flags);
1326 	if (desc == NULL)
1327 		return (NULL);
1328 
1329 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->fill;
1330 	if (g_ioat_debug_level >= 3)
1331 		dump_descriptor(hw_desc);
1332 
1333 	ioat_submit_single(ioat);
1334 	return (&desc->bus_dmadesc);
1335 }
1336 
1337 /*
1338  * Ring Management
1339  */
1340 static inline uint32_t
1341 ioat_get_active(struct ioat_softc *ioat)
1342 {
1343 
1344 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
1345 }
1346 
1347 static inline uint32_t
1348 ioat_get_ring_space(struct ioat_softc *ioat)
1349 {
1350 
1351 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
1352 }
1353 
1354 /*
1355  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
1356  * for 'num_descs'.
1357  *
1358  * If mflags contains M_WAITOK, blocks until enough space is available.
1359  *
1360  * Returns zero on success, or an errno on error.  If num_descs is beyond the
1361  * maximum ring size, returns EINVAl; if allocation would block and mflags
1362  * contains M_NOWAIT, returns EAGAIN.
1363  *
1364  * Must be called with the submit_lock held; returns with the lock held.  The
1365  * lock may be dropped to allocate the ring.
1366  *
1367  * (The submit_lock is needed to add any entries to the ring, so callers are
1368  * assured enough room is available.)
1369  */
1370 static int
1371 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
1372 {
1373 	boolean_t dug;
1374 	int error;
1375 
1376 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1377 	error = 0;
1378 	dug = FALSE;
1379 
1380 	if (num_descs < 1 || num_descs >= (1 << ioat->ring_size_order)) {
1381 		error = EINVAL;
1382 		goto out;
1383 	}
1384 
1385 	for (;;) {
1386 		if (ioat->quiescing) {
1387 			error = ENXIO;
1388 			goto out;
1389 		}
1390 
1391 		if (ioat_get_ring_space(ioat) >= num_descs)
1392 			goto out;
1393 
1394 		CTR3(KTR_IOAT, "%s channel=%u starved (%u)", __func__,
1395 		    ioat->chan_idx, num_descs);
1396 
1397 		if (!dug && !ioat->is_submitter_processing) {
1398 			ioat->is_submitter_processing = TRUE;
1399 			mtx_unlock(&ioat->submit_lock);
1400 
1401 			CTR2(KTR_IOAT, "%s channel=%u attempting to process events",
1402 			    __func__, ioat->chan_idx);
1403 			ioat_process_events(ioat);
1404 
1405 			mtx_lock(&ioat->submit_lock);
1406 			dug = TRUE;
1407 			KASSERT(ioat->is_submitter_processing == TRUE,
1408 			    ("is_submitter_processing"));
1409 			ioat->is_submitter_processing = FALSE;
1410 			wakeup(&ioat->tail);
1411 			continue;
1412 		}
1413 
1414 		if ((mflags & M_WAITOK) == 0) {
1415 			error = EAGAIN;
1416 			break;
1417 		}
1418 		CTR2(KTR_IOAT, "%s channel=%u blocking on completions",
1419 		    __func__, ioat->chan_idx);
1420 		msleep(&ioat->tail, &ioat->submit_lock, 0,
1421 		    "ioat_full", 0);
1422 		continue;
1423 	}
1424 
1425 out:
1426 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1427 	KASSERT(!ioat->quiescing || error == ENXIO,
1428 	    ("reserved during quiesce"));
1429 	return (error);
1430 }
1431 
1432 static void
1433 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1434     struct ioat_descriptor *ring)
1435 {
1436 
1437 	free(ring, M_IOAT);
1438 }
1439 
1440 static struct ioat_descriptor *
1441 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1442 {
1443 
1444 	return (&ioat->ring[index % (1 << ioat->ring_size_order)]);
1445 }
1446 
1447 static union ioat_hw_descriptor *
1448 ioat_get_descriptor(struct ioat_softc *ioat, uint32_t index)
1449 {
1450 
1451 	return (&ioat->hw_desc_ring[index % (1 << ioat->ring_size_order)]);
1452 }
1453 
1454 static void
1455 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1456 {
1457 	union ioat_hw_descriptor *desc;
1458 
1459 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1460 	    IOAT_CHANERR_STR);
1461 	if (chanerr == 0)
1462 		return;
1463 
1464 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1465 
1466 	desc = ioat_get_descriptor(ioat, ioat->tail + 0);
1467 	dump_descriptor(desc);
1468 
1469 	desc = ioat_get_descriptor(ioat, ioat->tail + 1);
1470 	dump_descriptor(desc);
1471 }
1472 
1473 static void
1474 ioat_poll_timer_callback(void *arg)
1475 {
1476 	struct ioat_softc *ioat;
1477 
1478 	ioat = arg;
1479 	ioat_log_message(3, "%s\n", __func__);
1480 
1481 	ioat_process_events(ioat);
1482 }
1483 
1484 /*
1485  * Support Functions
1486  */
1487 static void
1488 ioat_submit_single(struct ioat_softc *ioat)
1489 {
1490 
1491 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1492 
1493 	ioat_get(ioat, IOAT_ACTIVE_DESCR_REF);
1494 	atomic_add_rel_int(&ioat->head, 1);
1495 	atomic_add_rel_int(&ioat->hw_head, 1);
1496 	CTR5(KTR_IOAT, "%s channel=%u head=%u hw_head=%u tail=%u", __func__,
1497 	    ioat->chan_idx, ioat->head, ioat->hw_head & UINT16_MAX,
1498 	    ioat->tail);
1499 
1500 	ioat->stats.descriptors_submitted++;
1501 }
1502 
1503 static int
1504 ioat_reset_hw(struct ioat_softc *ioat)
1505 {
1506 	uint64_t status;
1507 	uint32_t chanerr;
1508 	unsigned timeout;
1509 	int error;
1510 
1511 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1512 
1513 	mtx_lock(IOAT_REFLK);
1514 	while (ioat->resetting && !ioat->destroying)
1515 		msleep(&ioat->resetting, IOAT_REFLK, 0, "IRH_drain", 0);
1516 	if (ioat->destroying) {
1517 		mtx_unlock(IOAT_REFLK);
1518 		return (ENXIO);
1519 	}
1520 	ioat->resetting = TRUE;
1521 
1522 	ioat->quiescing = TRUE;
1523 	ioat_drain_locked(ioat);
1524 	mtx_unlock(IOAT_REFLK);
1525 
1526 	/*
1527 	 * Suspend ioat_process_events while the hardware and softc are in an
1528 	 * indeterminate state.
1529 	 */
1530 	mtx_lock(&ioat->cleanup_lock);
1531 	ioat->resetting_cleanup = TRUE;
1532 	mtx_unlock(&ioat->cleanup_lock);
1533 
1534 	CTR2(KTR_IOAT, "%s channel=%u quiesced and drained", __func__,
1535 	    ioat->chan_idx);
1536 
1537 	status = ioat_get_chansts(ioat);
1538 	if (is_ioat_active(status) || is_ioat_idle(status))
1539 		ioat_suspend(ioat);
1540 
1541 	/* Wait at most 20 ms */
1542 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1543 	    timeout < 20; timeout++) {
1544 		DELAY(1000);
1545 		status = ioat_get_chansts(ioat);
1546 	}
1547 	if (timeout == 20) {
1548 		error = ETIMEDOUT;
1549 		goto out;
1550 	}
1551 
1552 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1553 
1554 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1555 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1556 
1557 	CTR2(KTR_IOAT, "%s channel=%u hardware suspended", __func__,
1558 	    ioat->chan_idx);
1559 
1560 	/*
1561 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1562 	 *  that can cause stability issues for IOAT v3.
1563 	 */
1564 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1565 	    4);
1566 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1567 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1568 
1569 	/*
1570 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1571 	 * Save/restore their contents manually.
1572 	 */
1573 	if (ioat_model_resets_msix(ioat)) {
1574 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1575 		pci_save_state(ioat->device);
1576 	}
1577 
1578 	ioat_reset(ioat);
1579 	CTR2(KTR_IOAT, "%s channel=%u hardware reset", __func__,
1580 	    ioat->chan_idx);
1581 
1582 	/* Wait at most 20 ms */
1583 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1584 		DELAY(1000);
1585 	if (timeout == 20) {
1586 		error = ETIMEDOUT;
1587 		goto out;
1588 	}
1589 
1590 	if (ioat_model_resets_msix(ioat)) {
1591 		ioat_log_message(1, "device resets registers; restored\n");
1592 		pci_restore_state(ioat->device);
1593 	}
1594 
1595 	/* Reset attempts to return the hardware to "halted." */
1596 	status = ioat_get_chansts(ioat);
1597 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1598 		/* So this really shouldn't happen... */
1599 		ioat_log_message(0, "Device is active after a reset?\n");
1600 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1601 		error = 0;
1602 		goto out;
1603 	}
1604 
1605 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1606 	if (chanerr != 0) {
1607 		mtx_lock(&ioat->cleanup_lock);
1608 		ioat_halted_debug(ioat, chanerr);
1609 		mtx_unlock(&ioat->cleanup_lock);
1610 		error = EIO;
1611 		goto out;
1612 	}
1613 
1614 	/*
1615 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1616 	 * device back to active.
1617 	 *
1618 	 * The internal ring counter resets to zero, so we have to start over
1619 	 * at zero as well.
1620 	 */
1621 	ioat->tail = ioat->head = ioat->hw_head = 0;
1622 	ioat->last_seen = 0;
1623 	*ioat->comp_update = 0;
1624 	KASSERT(!ioat->is_completion_pending, ("bogus completion_pending"));
1625 
1626 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1627 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1628 	ioat_write_chainaddr(ioat, RING_PHYS_ADDR(ioat, 0));
1629 	error = 0;
1630 	CTR2(KTR_IOAT, "%s channel=%u configured channel", __func__,
1631 	    ioat->chan_idx);
1632 
1633 out:
1634 	/* Enqueues a null operation and ensures it completes. */
1635 	if (error == 0) {
1636 		error = ioat_start_channel(ioat);
1637 		CTR2(KTR_IOAT, "%s channel=%u started channel", __func__,
1638 		    ioat->chan_idx);
1639 	}
1640 
1641 	/*
1642 	 * Resume completions now that ring state is consistent.
1643 	 */
1644 	mtx_lock(&ioat->cleanup_lock);
1645 	ioat->resetting_cleanup = FALSE;
1646 	mtx_unlock(&ioat->cleanup_lock);
1647 
1648 	/* Unblock submission of new work */
1649 	mtx_lock(IOAT_REFLK);
1650 	ioat->quiescing = FALSE;
1651 	wakeup(&ioat->quiescing);
1652 
1653 	ioat->resetting = FALSE;
1654 	wakeup(&ioat->resetting);
1655 
1656 	if (ioat->is_completion_pending)
1657 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
1658 		    ioat);
1659 	CTR2(KTR_IOAT, "%s channel=%u reset done", __func__, ioat->chan_idx);
1660 	mtx_unlock(IOAT_REFLK);
1661 
1662 	return (error);
1663 }
1664 
1665 static int
1666 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1667 {
1668 	struct ioat_softc *ioat;
1669 	struct sbuf sb;
1670 	uint64_t status;
1671 	int error;
1672 
1673 	ioat = arg1;
1674 
1675 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1676 
1677 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1678 	switch (status) {
1679 	case IOAT_CHANSTS_ACTIVE:
1680 		sbuf_printf(&sb, "ACTIVE");
1681 		break;
1682 	case IOAT_CHANSTS_IDLE:
1683 		sbuf_printf(&sb, "IDLE");
1684 		break;
1685 	case IOAT_CHANSTS_SUSPENDED:
1686 		sbuf_printf(&sb, "SUSPENDED");
1687 		break;
1688 	case IOAT_CHANSTS_HALTED:
1689 		sbuf_printf(&sb, "HALTED");
1690 		break;
1691 	case IOAT_CHANSTS_ARMED:
1692 		sbuf_printf(&sb, "ARMED");
1693 		break;
1694 	default:
1695 		sbuf_printf(&sb, "UNKNOWN");
1696 		break;
1697 	}
1698 	error = sbuf_finish(&sb);
1699 	sbuf_delete(&sb);
1700 
1701 	if (error != 0 || req->newptr == NULL)
1702 		return (error);
1703 	return (EINVAL);
1704 }
1705 
1706 static int
1707 sysctl_handle_dpi(SYSCTL_HANDLER_ARGS)
1708 {
1709 	struct ioat_softc *ioat;
1710 	struct sbuf sb;
1711 #define	PRECISION	"1"
1712 	const uintmax_t factor = 10;
1713 	uintmax_t rate;
1714 	int error;
1715 
1716 	ioat = arg1;
1717 	sbuf_new_for_sysctl(&sb, NULL, 16, req);
1718 
1719 	if (ioat->stats.interrupts == 0) {
1720 		sbuf_printf(&sb, "NaN");
1721 		goto out;
1722 	}
1723 	rate = ioat->stats.descriptors_processed * factor /
1724 	    ioat->stats.interrupts;
1725 	sbuf_printf(&sb, "%ju.%." PRECISION "ju", rate / factor,
1726 	    rate % factor);
1727 #undef	PRECISION
1728 out:
1729 	error = sbuf_finish(&sb);
1730 	sbuf_delete(&sb);
1731 	if (error != 0 || req->newptr == NULL)
1732 		return (error);
1733 	return (EINVAL);
1734 }
1735 
1736 static int
1737 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
1738 {
1739 	struct ioat_softc *ioat;
1740 	int error, arg;
1741 
1742 	ioat = arg1;
1743 
1744 	arg = 0;
1745 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1746 	if (error != 0 || req->newptr == NULL)
1747 		return (error);
1748 
1749 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1750 	if (error != 0)
1751 		return (error);
1752 
1753 	if (arg != 0)
1754 		error = ioat_reset_hw(ioat);
1755 
1756 	return (error);
1757 }
1758 
1759 static void
1760 dump_descriptor(void *hw_desc)
1761 {
1762 	int i, j;
1763 
1764 	for (i = 0; i < 2; i++) {
1765 		for (j = 0; j < 8; j++)
1766 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
1767 		printf("\n");
1768 	}
1769 }
1770 
1771 static void
1772 ioat_setup_sysctl(device_t device)
1773 {
1774 	struct sysctl_oid_list *par, *statpar, *state, *hammer;
1775 	struct sysctl_ctx_list *ctx;
1776 	struct sysctl_oid *tree, *tmp;
1777 	struct ioat_softc *ioat;
1778 
1779 	ioat = DEVICE2SOFTC(device);
1780 	ctx = device_get_sysctl_ctx(device);
1781 	tree = device_get_sysctl_tree(device);
1782 	par = SYSCTL_CHILDREN(tree);
1783 
1784 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
1785 	    &ioat->version, 0, "HW version (0xMM form)");
1786 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
1787 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
1788 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "intrdelay_supported", CTLFLAG_RD,
1789 	    &ioat->intrdelay_supported, 0, "Is INTRDELAY supported");
1790 	SYSCTL_ADD_U16(ctx, par, OID_AUTO, "intrdelay_max", CTLFLAG_RD,
1791 	    &ioat->intrdelay_max, 0,
1792 	    "Maximum configurable INTRDELAY on this channel (microseconds)");
1793 
1794 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "state", CTLFLAG_RD, NULL,
1795 	    "IOAT channel internal state");
1796 	state = SYSCTL_CHILDREN(tmp);
1797 
1798 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "ring_size_order", CTLFLAG_RD,
1799 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
1800 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "head", CTLFLAG_RD, &ioat->head,
1801 	    0, "SW descriptor head pointer index");
1802 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail,
1803 	    0, "SW descriptor tail pointer index");
1804 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "hw_head", CTLFLAG_RD,
1805 	    &ioat->hw_head, 0, "HW DMACOUNT");
1806 
1807 	SYSCTL_ADD_UQUAD(ctx, state, OID_AUTO, "last_completion", CTLFLAG_RD,
1808 	    ioat->comp_update, "HW addr of last completion");
1809 
1810 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_submitter_processing",
1811 	    CTLFLAG_RD, &ioat->is_submitter_processing, 0,
1812 	    "submitter processing");
1813 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_completion_pending",
1814 	    CTLFLAG_RD, &ioat->is_completion_pending, 0, "completion pending");
1815 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_reset_pending", CTLFLAG_RD,
1816 	    &ioat->is_reset_pending, 0, "reset pending");
1817 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_channel_running", CTLFLAG_RD,
1818 	    &ioat->is_channel_running, 0, "channel running");
1819 
1820 	SYSCTL_ADD_PROC(ctx, state, OID_AUTO, "chansts",
1821 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
1822 	    "String of the channel status");
1823 
1824 	SYSCTL_ADD_U16(ctx, state, OID_AUTO, "intrdelay", CTLFLAG_RD,
1825 	    &ioat->cached_intrdelay, 0,
1826 	    "Current INTRDELAY on this channel (cached, microseconds)");
1827 
1828 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "hammer", CTLFLAG_RD, NULL,
1829 	    "Big hammers (mostly for testing)");
1830 	hammer = SYSCTL_CHILDREN(tmp);
1831 
1832 	SYSCTL_ADD_PROC(ctx, hammer, OID_AUTO, "force_hw_reset",
1833 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
1834 	    "Set to non-zero to reset the hardware");
1835 
1836 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "stats", CTLFLAG_RD, NULL,
1837 	    "IOAT channel statistics");
1838 	statpar = SYSCTL_CHILDREN(tmp);
1839 
1840 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "interrupts", CTLFLAG_RW,
1841 	    &ioat->stats.interrupts,
1842 	    "Number of interrupts processed on this channel");
1843 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "descriptors", CTLFLAG_RW,
1844 	    &ioat->stats.descriptors_processed,
1845 	    "Number of descriptors processed on this channel");
1846 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "submitted", CTLFLAG_RW,
1847 	    &ioat->stats.descriptors_submitted,
1848 	    "Number of descriptors submitted to this channel");
1849 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "errored", CTLFLAG_RW,
1850 	    &ioat->stats.descriptors_error,
1851 	    "Number of descriptors failed by channel errors");
1852 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "halts", CTLFLAG_RW,
1853 	    &ioat->stats.channel_halts, 0,
1854 	    "Number of times the channel has halted");
1855 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "last_halt_chanerr", CTLFLAG_RW,
1856 	    &ioat->stats.last_halt_chanerr, 0,
1857 	    "The raw CHANERR when the channel was last halted");
1858 
1859 	SYSCTL_ADD_PROC(ctx, statpar, OID_AUTO, "desc_per_interrupt",
1860 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_dpi, "A",
1861 	    "Descriptors per interrupt");
1862 }
1863 
1864 static inline struct ioat_softc *
1865 ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1866 {
1867 	uint32_t old;
1868 
1869 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1870 
1871 	old = atomic_fetchadd_32(&ioat->refcnt, 1);
1872 	KASSERT(old < UINT32_MAX, ("refcnt overflow"));
1873 
1874 #ifdef INVARIANTS
1875 	old = atomic_fetchadd_32(&ioat->refkinds[kind], 1);
1876 	KASSERT(old < UINT32_MAX, ("refcnt kind overflow"));
1877 #endif
1878 
1879 	return (ioat);
1880 }
1881 
1882 static inline void
1883 ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1884 {
1885 
1886 	_ioat_putn(ioat, n, kind, FALSE);
1887 }
1888 
1889 static inline void
1890 ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1891 {
1892 
1893 	_ioat_putn(ioat, n, kind, TRUE);
1894 }
1895 
1896 static inline void
1897 _ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
1898     boolean_t locked)
1899 {
1900 	uint32_t old;
1901 
1902 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1903 
1904 	if (n == 0)
1905 		return;
1906 
1907 #ifdef INVARIANTS
1908 	old = atomic_fetchadd_32(&ioat->refkinds[kind], -n);
1909 	KASSERT(old >= n, ("refcnt kind underflow"));
1910 #endif
1911 
1912 	/* Skip acquiring the lock if resulting refcnt > 0. */
1913 	for (;;) {
1914 		old = ioat->refcnt;
1915 		if (old <= n)
1916 			break;
1917 		if (atomic_cmpset_32(&ioat->refcnt, old, old - n))
1918 			return;
1919 	}
1920 
1921 	if (locked)
1922 		mtx_assert(IOAT_REFLK, MA_OWNED);
1923 	else
1924 		mtx_lock(IOAT_REFLK);
1925 
1926 	old = atomic_fetchadd_32(&ioat->refcnt, -n);
1927 	KASSERT(old >= n, ("refcnt error"));
1928 
1929 	if (old == n)
1930 		wakeup(IOAT_REFLK);
1931 	if (!locked)
1932 		mtx_unlock(IOAT_REFLK);
1933 }
1934 
1935 static inline void
1936 ioat_put(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1937 {
1938 
1939 	ioat_putn(ioat, 1, kind);
1940 }
1941 
1942 static void
1943 ioat_drain_locked(struct ioat_softc *ioat)
1944 {
1945 
1946 	mtx_assert(IOAT_REFLK, MA_OWNED);
1947 	while (ioat->refcnt > 0)
1948 		msleep(IOAT_REFLK, IOAT_REFLK, 0, "ioat_drain", 0);
1949 }
1950 
1951 #ifdef DDB
1952 #define	_db_show_lock(lo)	LOCK_CLASS(lo)->lc_ddb_show(lo)
1953 #define	db_show_lock(lk)	_db_show_lock(&(lk)->lock_object)
1954 DB_SHOW_COMMAND(ioat, db_show_ioat)
1955 {
1956 	struct ioat_softc *sc;
1957 	unsigned idx;
1958 
1959 	if (!have_addr)
1960 		goto usage;
1961 	idx = (unsigned)addr;
1962 	if (idx >= ioat_channel_index)
1963 		goto usage;
1964 
1965 	sc = ioat_channel[idx];
1966 	db_printf("ioat softc at %p\n", sc);
1967 	if (sc == NULL)
1968 		return;
1969 
1970 	db_printf(" version: %d\n", sc->version);
1971 	db_printf(" chan_idx: %u\n", sc->chan_idx);
1972 	db_printf(" submit_lock: ");
1973 	db_show_lock(&sc->submit_lock);
1974 
1975 	db_printf(" capabilities: %b\n", (int)sc->capabilities,
1976 	    IOAT_DMACAP_STR);
1977 	db_printf(" cached_intrdelay: %u\n", sc->cached_intrdelay);
1978 	db_printf(" *comp_update: 0x%jx\n", (uintmax_t)*sc->comp_update);
1979 
1980 	db_printf(" poll_timer:\n");
1981 	db_printf("  c_time: %ju\n", (uintmax_t)sc->poll_timer.c_time);
1982 	db_printf("  c_arg: %p\n", sc->poll_timer.c_arg);
1983 	db_printf("  c_func: %p\n", sc->poll_timer.c_func);
1984 	db_printf("  c_lock: %p\n", sc->poll_timer.c_lock);
1985 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->poll_timer.c_flags);
1986 
1987 	db_printf(" quiescing: %d\n", (int)sc->quiescing);
1988 	db_printf(" destroying: %d\n", (int)sc->destroying);
1989 	db_printf(" is_submitter_processing: %d\n",
1990 	    (int)sc->is_submitter_processing);
1991 	db_printf(" is_completion_pending: %d\n", (int)sc->is_completion_pending);
1992 	db_printf(" is_reset_pending: %d\n", (int)sc->is_reset_pending);
1993 	db_printf(" is_channel_running: %d\n", (int)sc->is_channel_running);
1994 	db_printf(" intrdelay_supported: %d\n", (int)sc->intrdelay_supported);
1995 	db_printf(" resetting: %d\n", (int)sc->resetting);
1996 
1997 	db_printf(" head: %u\n", sc->head);
1998 	db_printf(" tail: %u\n", sc->tail);
1999 	db_printf(" hw_head: %u\n", sc->hw_head);
2000 	db_printf(" ring_size_order: %u\n", sc->ring_size_order);
2001 	db_printf(" last_seen: 0x%lx\n", sc->last_seen);
2002 	db_printf(" ring: %p\n", sc->ring);
2003 	db_printf(" descriptors: %p\n", sc->hw_desc_ring);
2004 	db_printf(" descriptors (phys): 0x%jx\n",
2005 	    (uintmax_t)sc->hw_desc_bus_addr);
2006 
2007 	db_printf("  ring[%u] (tail):\n", sc->tail %
2008 	    (1 << sc->ring_size_order));
2009 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->tail)->id);
2010 	db_printf("   addr: 0x%lx\n",
2011 	    RING_PHYS_ADDR(sc, sc->tail));
2012 	db_printf("   next: 0x%lx\n",
2013 	     ioat_get_descriptor(sc, sc->tail)->generic.next);
2014 
2015 	db_printf("  ring[%u] (head - 1):\n", (sc->head - 1) %
2016 	    (1 << sc->ring_size_order));
2017 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head - 1)->id);
2018 	db_printf("   addr: 0x%lx\n",
2019 	    RING_PHYS_ADDR(sc, sc->head - 1));
2020 	db_printf("   next: 0x%lx\n",
2021 	     ioat_get_descriptor(sc, sc->head - 1)->generic.next);
2022 
2023 	db_printf("  ring[%u] (head):\n", (sc->head) %
2024 	    (1 << sc->ring_size_order));
2025 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head)->id);
2026 	db_printf("   addr: 0x%lx\n",
2027 	    RING_PHYS_ADDR(sc, sc->head));
2028 	db_printf("   next: 0x%lx\n",
2029 	     ioat_get_descriptor(sc, sc->head)->generic.next);
2030 
2031 	for (idx = 0; idx < (1 << sc->ring_size_order); idx++)
2032 		if ((*sc->comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK)
2033 		    == RING_PHYS_ADDR(sc, idx))
2034 			db_printf("  ring[%u] == hardware tail\n", idx);
2035 
2036 	db_printf(" cleanup_lock: ");
2037 	db_show_lock(&sc->cleanup_lock);
2038 
2039 	db_printf(" refcnt: %u\n", sc->refcnt);
2040 #ifdef INVARIANTS
2041 	CTASSERT(IOAT_NUM_REF_KINDS == 2);
2042 	db_printf(" refkinds: [ENG=%u, DESCR=%u]\n", sc->refkinds[0],
2043 	    sc->refkinds[1]);
2044 #endif
2045 	db_printf(" stats:\n");
2046 	db_printf("  interrupts: %lu\n", sc->stats.interrupts);
2047 	db_printf("  descriptors_processed: %lu\n", sc->stats.descriptors_processed);
2048 	db_printf("  descriptors_error: %lu\n", sc->stats.descriptors_error);
2049 	db_printf("  descriptors_submitted: %lu\n", sc->stats.descriptors_submitted);
2050 
2051 	db_printf("  channel_halts: %u\n", sc->stats.channel_halts);
2052 	db_printf("  last_halt_chanerr: %u\n", sc->stats.last_halt_chanerr);
2053 
2054 	if (db_pager_quit)
2055 		return;
2056 
2057 	db_printf(" hw status:\n");
2058 	db_printf("  status: 0x%lx\n", ioat_get_chansts(sc));
2059 	db_printf("  chanctrl: 0x%x\n",
2060 	    (unsigned)ioat_read_2(sc, IOAT_CHANCTRL_OFFSET));
2061 	db_printf("  chancmd: 0x%x\n",
2062 	    (unsigned)ioat_read_1(sc, IOAT_CHANCMD_OFFSET));
2063 	db_printf("  dmacount: 0x%x\n",
2064 	    (unsigned)ioat_read_2(sc, IOAT_DMACOUNT_OFFSET));
2065 	db_printf("  chainaddr: 0x%lx\n",
2066 	    ioat_read_double_4(sc, IOAT_CHAINADDR_OFFSET_LOW));
2067 	db_printf("  chancmp: 0x%lx\n",
2068 	    ioat_read_double_4(sc, IOAT_CHANCMP_OFFSET_LOW));
2069 	db_printf("  chanerr: %b\n",
2070 	    (int)ioat_read_4(sc, IOAT_CHANERR_OFFSET), IOAT_CHANERR_STR);
2071 	return;
2072 usage:
2073 	db_printf("usage: show ioat <0-%u>\n", ioat_channel_index);
2074 	return;
2075 }
2076 #endif /* DDB */
2077