xref: /freebsd/sys/dev/ioat/ioat.c (revision 2a243b9539a45b392a515569cab2091844cf2bdf)
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 
241 MODULE_PNP_INFO("W32:vendor/device;D:human", pci, ioat, pci_ids,
242     sizeof(pci_ids[0]), nitems(pci_ids));
243 
244 /*
245  * OS <-> Driver linkage functions
246  */
247 static int
248 ioat_probe(device_t device)
249 {
250 	struct _pcsid *ep;
251 	u_int32_t type;
252 
253 	type = pci_get_devid(device);
254 	for (ep = pci_ids; ep < &pci_ids[nitems(pci_ids)]; ep++) {
255 		if (ep->type == type) {
256 			device_set_desc(device, ep->desc);
257 			return (0);
258 		}
259 	}
260 	return (ENXIO);
261 }
262 
263 static int
264 ioat_attach(device_t device)
265 {
266 	struct ioat_softc *ioat;
267 	int error;
268 
269 	ioat = DEVICE2SOFTC(device);
270 	ioat->device = device;
271 
272 	error = ioat_map_pci_bar(ioat);
273 	if (error != 0)
274 		goto err;
275 
276 	ioat->version = ioat_read_cbver(ioat);
277 	if (ioat->version < IOAT_VER_3_0) {
278 		error = ENODEV;
279 		goto err;
280 	}
281 
282 	error = ioat3_attach(device);
283 	if (error != 0)
284 		goto err;
285 
286 	error = pci_enable_busmaster(device);
287 	if (error != 0)
288 		goto err;
289 
290 	error = ioat_setup_intr(ioat);
291 	if (error != 0)
292 		goto err;
293 
294 	error = ioat_reset_hw(ioat);
295 	if (error != 0)
296 		goto err;
297 
298 	ioat_process_events(ioat);
299 	ioat_setup_sysctl(device);
300 
301 	ioat->chan_idx = ioat_channel_index;
302 	ioat_channel[ioat_channel_index++] = ioat;
303 	ioat_test_attach();
304 
305 err:
306 	if (error != 0)
307 		ioat_detach(device);
308 	return (error);
309 }
310 
311 static int
312 ioat_detach(device_t device)
313 {
314 	struct ioat_softc *ioat;
315 
316 	ioat = DEVICE2SOFTC(device);
317 
318 	ioat_test_detach();
319 	taskqueue_drain(taskqueue_thread, &ioat->reset_task);
320 
321 	mtx_lock(IOAT_REFLK);
322 	ioat->quiescing = TRUE;
323 	ioat->destroying = TRUE;
324 	wakeup(&ioat->quiescing);
325 	wakeup(&ioat->resetting);
326 
327 	ioat_channel[ioat->chan_idx] = NULL;
328 
329 	ioat_drain_locked(ioat);
330 	mtx_unlock(IOAT_REFLK);
331 
332 	ioat_teardown_intr(ioat);
333 	callout_drain(&ioat->poll_timer);
334 
335 	pci_disable_busmaster(device);
336 
337 	if (ioat->pci_resource != NULL)
338 		bus_release_resource(device, SYS_RES_MEMORY,
339 		    ioat->pci_resource_id, ioat->pci_resource);
340 
341 	if (ioat->ring != NULL)
342 		ioat_free_ring(ioat, 1 << ioat->ring_size_order, ioat->ring);
343 
344 	if (ioat->comp_update != NULL) {
345 		bus_dmamap_unload(ioat->comp_update_tag, ioat->comp_update_map);
346 		bus_dmamem_free(ioat->comp_update_tag, ioat->comp_update,
347 		    ioat->comp_update_map);
348 		bus_dma_tag_destroy(ioat->comp_update_tag);
349 	}
350 
351 	if (ioat->hw_desc_ring != NULL) {
352 		bus_dmamap_unload(ioat->hw_desc_tag, ioat->hw_desc_map);
353 		bus_dmamem_free(ioat->hw_desc_tag, ioat->hw_desc_ring,
354 		    ioat->hw_desc_map);
355 		bus_dma_tag_destroy(ioat->hw_desc_tag);
356 	}
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 	hw_desc = &ioat_get_descriptor(ioat, ioat->head)->dma;
391 	dmadesc = &desc->bus_dmadesc;
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_dma_hw_descriptor *dma_hw_desc;
430 	void *hw_desc;
431 	size_t ringsz;
432 	int i, num_descriptors;
433 	int error;
434 	uint8_t xfercap;
435 
436 	error = 0;
437 	ioat = DEVICE2SOFTC(device);
438 	ioat->capabilities = ioat_read_dmacapability(ioat);
439 
440 	ioat_log_message(0, "Capabilities: %b\n", (int)ioat->capabilities,
441 	    IOAT_DMACAP_STR);
442 
443 	xfercap = ioat_read_xfercap(ioat);
444 	ioat->max_xfer_size = 1 << xfercap;
445 
446 	ioat->intrdelay_supported = (ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) &
447 	    IOAT_INTRDELAY_SUPPORTED) != 0;
448 	if (ioat->intrdelay_supported)
449 		ioat->intrdelay_max = IOAT_INTRDELAY_US_MASK;
450 
451 	/* TODO: need to check DCA here if we ever do XOR/PQ */
452 
453 	mtx_init(&ioat->submit_lock, "ioat_submit", NULL, MTX_DEF);
454 	mtx_init(&ioat->cleanup_lock, "ioat_cleanup", NULL, MTX_DEF);
455 	callout_init(&ioat->poll_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_submitter_processing = FALSE;
465 	ioat->is_completion_pending = FALSE;
466 	ioat->is_reset_pending = FALSE;
467 	ioat->is_channel_running = FALSE;
468 
469 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), sizeof(uint64_t), 0x0,
470 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
471 	    sizeof(uint64_t), 1, sizeof(uint64_t), 0, NULL, NULL,
472 	    &ioat->comp_update_tag);
473 
474 	error = bus_dmamem_alloc(ioat->comp_update_tag,
475 	    (void **)&ioat->comp_update, BUS_DMA_ZERO, &ioat->comp_update_map);
476 	if (ioat->comp_update == NULL)
477 		return (ENOMEM);
478 
479 	error = bus_dmamap_load(ioat->comp_update_tag, ioat->comp_update_map,
480 	    ioat->comp_update, sizeof(uint64_t), ioat_comp_update_map, ioat,
481 	    0);
482 	if (error != 0)
483 		return (error);
484 
485 	ioat->ring_size_order = g_ioat_ring_order;
486 	num_descriptors = 1 << ioat->ring_size_order;
487 	ringsz = sizeof(struct ioat_dma_hw_descriptor) * num_descriptors;
488 
489 	error = bus_dma_tag_create(bus_get_dma_tag(ioat->device),
490 	    2 * 1024 * 1024, 0x0, (bus_addr_t)BUS_SPACE_MAXADDR_40BIT,
491 	    BUS_SPACE_MAXADDR, NULL, NULL, ringsz, 1, ringsz, 0, NULL, NULL,
492 	    &ioat->hw_desc_tag);
493 	if (error != 0)
494 		return (error);
495 
496 	error = bus_dmamem_alloc(ioat->hw_desc_tag, &hw_desc,
497 	    BUS_DMA_ZERO | BUS_DMA_WAITOK, &ioat->hw_desc_map);
498 	if (error != 0)
499 		return (error);
500 
501 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
502 	    ringsz, ioat_dmamap_cb, &ioat->hw_desc_bus_addr, BUS_DMA_WAITOK);
503 	if (error)
504 		return (error);
505 
506 	ioat->hw_desc_ring = hw_desc;
507 
508 	ioat->ring = malloc(num_descriptors * sizeof(*ring), M_IOAT,
509 	    M_ZERO | M_WAITOK);
510 
511 	ring = ioat->ring;
512 	for (i = 0; i < num_descriptors; i++) {
513 		memset(&ring[i].bus_dmadesc, 0, sizeof(ring[i].bus_dmadesc));
514 		ring[i].id = i;
515 	}
516 
517 	for (i = 0; i < num_descriptors; i++) {
518 		dma_hw_desc = &ioat->hw_desc_ring[i].dma;
519 		dma_hw_desc->next = RING_PHYS_ADDR(ioat, i + 1);
520 	}
521 
522 	ioat->head = ioat->hw_head = 0;
523 	ioat->tail = 0;
524 	ioat->last_seen = 0;
525 	*ioat->comp_update = 0;
526 	return (0);
527 }
528 
529 static int
530 ioat_map_pci_bar(struct ioat_softc *ioat)
531 {
532 
533 	ioat->pci_resource_id = PCIR_BAR(0);
534 	ioat->pci_resource = bus_alloc_resource_any(ioat->device,
535 	    SYS_RES_MEMORY, &ioat->pci_resource_id, RF_ACTIVE);
536 
537 	if (ioat->pci_resource == NULL) {
538 		ioat_log_message(0, "unable to allocate pci resource\n");
539 		return (ENODEV);
540 	}
541 
542 	ioat->pci_bus_tag = rman_get_bustag(ioat->pci_resource);
543 	ioat->pci_bus_handle = rman_get_bushandle(ioat->pci_resource);
544 	return (0);
545 }
546 
547 static void
548 ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
549 {
550 	struct ioat_softc *ioat = arg;
551 
552 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
553 	ioat->comp_update_bus_addr = seg[0].ds_addr;
554 }
555 
556 static void
557 ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
558 {
559 	bus_addr_t *baddr;
560 
561 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
562 	baddr = arg;
563 	*baddr = segs->ds_addr;
564 }
565 
566 /*
567  * Interrupt setup and handlers
568  */
569 static int
570 ioat_setup_intr(struct ioat_softc *ioat)
571 {
572 	uint32_t num_vectors;
573 	int error;
574 	boolean_t use_msix;
575 	boolean_t force_legacy_interrupts;
576 
577 	use_msix = FALSE;
578 	force_legacy_interrupts = FALSE;
579 
580 	if (!g_force_legacy_interrupts && pci_msix_count(ioat->device) >= 1) {
581 		num_vectors = 1;
582 		pci_alloc_msix(ioat->device, &num_vectors);
583 		if (num_vectors == 1)
584 			use_msix = TRUE;
585 	}
586 
587 	if (use_msix) {
588 		ioat->rid = 1;
589 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
590 		    &ioat->rid, RF_ACTIVE);
591 	} else {
592 		ioat->rid = 0;
593 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
594 		    &ioat->rid, RF_SHAREABLE | RF_ACTIVE);
595 	}
596 	if (ioat->res == NULL) {
597 		ioat_log_message(0, "bus_alloc_resource failed\n");
598 		return (ENOMEM);
599 	}
600 
601 	ioat->tag = NULL;
602 	error = bus_setup_intr(ioat->device, ioat->res, INTR_MPSAFE |
603 	    INTR_TYPE_MISC, NULL, ioat_interrupt_handler, ioat, &ioat->tag);
604 	if (error != 0) {
605 		ioat_log_message(0, "bus_setup_intr failed\n");
606 		return (error);
607 	}
608 
609 	ioat_write_intrctrl(ioat, IOAT_INTRCTRL_MASTER_INT_EN);
610 	return (0);
611 }
612 
613 static boolean_t
614 ioat_model_resets_msix(struct ioat_softc *ioat)
615 {
616 	u_int32_t pciid;
617 
618 	pciid = pci_get_devid(ioat->device);
619 	switch (pciid) {
620 		/* BWD: */
621 	case 0x0c508086:
622 	case 0x0c518086:
623 	case 0x0c528086:
624 	case 0x0c538086:
625 		/* BDXDE: */
626 	case 0x6f508086:
627 	case 0x6f518086:
628 	case 0x6f528086:
629 	case 0x6f538086:
630 		return (TRUE);
631 	}
632 
633 	return (FALSE);
634 }
635 
636 static void
637 ioat_interrupt_handler(void *arg)
638 {
639 	struct ioat_softc *ioat = arg;
640 
641 	ioat->stats.interrupts++;
642 	ioat_process_events(ioat);
643 }
644 
645 static int
646 chanerr_to_errno(uint32_t chanerr)
647 {
648 
649 	if (chanerr == 0)
650 		return (0);
651 	if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
652 		return (EFAULT);
653 	if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
654 		return (EIO);
655 	/* This one is probably our fault: */
656 	if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
657 		return (EIO);
658 	return (EIO);
659 }
660 
661 static void
662 ioat_process_events(struct ioat_softc *ioat)
663 {
664 	struct ioat_descriptor *desc;
665 	struct bus_dmadesc *dmadesc;
666 	uint64_t comp_update, status;
667 	uint32_t completed, chanerr;
668 	boolean_t pending;
669 	int error;
670 
671 	mtx_lock(&ioat->cleanup_lock);
672 
673 	/*
674 	 * Don't run while the hardware is being reset.  Reset is responsible
675 	 * for blocking new work and draining & completing existing work, so
676 	 * there is nothing to do until new work is queued after reset anyway.
677 	 */
678 	if (ioat->resetting_cleanup) {
679 		mtx_unlock(&ioat->cleanup_lock);
680 		return;
681 	}
682 
683 	completed = 0;
684 	comp_update = *ioat->comp_update;
685 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
686 
687 	if (status < ioat->hw_desc_bus_addr ||
688 	    status >= ioat->hw_desc_bus_addr + (1 << ioat->ring_size_order) *
689 	    sizeof(struct ioat_generic_hw_descriptor))
690 		panic("Bogus completion address %jx (channel %u)",
691 		    (uintmax_t)status, ioat->chan_idx);
692 
693 	if (status == ioat->last_seen) {
694 		/*
695 		 * If we landed in process_events and nothing has been
696 		 * completed, check for a timeout due to channel halt.
697 		 */
698 		goto out;
699 	}
700 	CTR4(KTR_IOAT, "%s channel=%u hw_status=0x%lx last_seen=0x%lx",
701 	    __func__, ioat->chan_idx, comp_update, ioat->last_seen);
702 
703 	while (RING_PHYS_ADDR(ioat, ioat->tail - 1) != status) {
704 		desc = ioat_get_ring_entry(ioat, ioat->tail);
705 		dmadesc = &desc->bus_dmadesc;
706 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) ok  cb %p(%p)",
707 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
708 		    dmadesc->callback_arg);
709 
710 		if (dmadesc->callback_fn != NULL)
711 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
712 
713 		completed++;
714 		ioat->tail++;
715 	}
716 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
717 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
718 
719 	if (completed != 0) {
720 		ioat->last_seen = RING_PHYS_ADDR(ioat, ioat->tail - 1);
721 		ioat->stats.descriptors_processed += completed;
722 	}
723 
724 out:
725 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
726 
727 	/* Perform a racy check first; only take the locks if it passes. */
728 	pending = (ioat_get_active(ioat) != 0);
729 	if (!pending && ioat->is_completion_pending) {
730 		mtx_unlock(&ioat->cleanup_lock);
731 		mtx_lock(&ioat->submit_lock);
732 		mtx_lock(&ioat->cleanup_lock);
733 
734 		pending = (ioat_get_active(ioat) != 0);
735 		if (!pending && ioat->is_completion_pending) {
736 			ioat->is_completion_pending = FALSE;
737 			callout_stop(&ioat->poll_timer);
738 		}
739 		mtx_unlock(&ioat->submit_lock);
740 	}
741 	mtx_unlock(&ioat->cleanup_lock);
742 
743 	if (pending)
744 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
745 		    ioat);
746 
747 	if (completed != 0) {
748 		ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
749 		wakeup(&ioat->tail);
750 	}
751 
752 	/*
753 	 * The device doesn't seem to reliably push suspend/halt statuses to
754 	 * the channel completion memory address, so poll the device register
755 	 * here.
756 	 */
757 	comp_update = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
758 	if (!is_ioat_halted(comp_update) && !is_ioat_suspended(comp_update))
759 		return;
760 
761 	ioat->stats.channel_halts++;
762 
763 	/*
764 	 * Fatal programming error on this DMA channel.  Flush any outstanding
765 	 * work with error status and restart the engine.
766 	 */
767 	mtx_lock(&ioat->submit_lock);
768 	mtx_lock(&ioat->cleanup_lock);
769 	ioat->quiescing = TRUE;
770 	/*
771 	 * This is safe to do here because we have both locks and the submit
772 	 * queue is quiesced.  We know that we will drain all outstanding
773 	 * events, so ioat_reset_hw can't deadlock.  It is necessary to
774 	 * protect other ioat_process_event threads from racing ioat_reset_hw,
775 	 * reading an indeterminate hw state, and attempting to continue
776 	 * issuing completions.
777 	 */
778 	ioat->resetting_cleanup = TRUE;
779 
780 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
781 	if (1 <= g_ioat_debug_level)
782 		ioat_halted_debug(ioat, chanerr);
783 	ioat->stats.last_halt_chanerr = chanerr;
784 
785 	while (ioat_get_active(ioat) > 0) {
786 		desc = ioat_get_ring_entry(ioat, ioat->tail);
787 		dmadesc = &desc->bus_dmadesc;
788 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) err cb %p(%p)",
789 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
790 		    dmadesc->callback_arg);
791 
792 		if (dmadesc->callback_fn != NULL)
793 			dmadesc->callback_fn(dmadesc->callback_arg,
794 			    chanerr_to_errno(chanerr));
795 
796 		ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
797 		ioat->tail++;
798 		ioat->stats.descriptors_processed++;
799 		ioat->stats.descriptors_error++;
800 	}
801 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
802 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
803 
804 	if (ioat->is_completion_pending) {
805 		ioat->is_completion_pending = FALSE;
806 		callout_stop(&ioat->poll_timer);
807 	}
808 
809 	/* Clear error status */
810 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
811 
812 	mtx_unlock(&ioat->cleanup_lock);
813 	mtx_unlock(&ioat->submit_lock);
814 
815 	ioat_log_message(0, "Resetting channel to recover from error\n");
816 	error = taskqueue_enqueue(taskqueue_thread, &ioat->reset_task);
817 	KASSERT(error == 0,
818 	    ("%s: taskqueue_enqueue failed: %d", __func__, error));
819 }
820 
821 static void
822 ioat_reset_hw_task(void *ctx, int pending __unused)
823 {
824 	struct ioat_softc *ioat;
825 	int error;
826 
827 	ioat = ctx;
828 	ioat_log_message(1, "%s: Resetting channel\n", __func__);
829 
830 	error = ioat_reset_hw(ioat);
831 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
832 	(void)error;
833 }
834 
835 /*
836  * User API functions
837  */
838 unsigned
839 ioat_get_nchannels(void)
840 {
841 
842 	return (ioat_channel_index);
843 }
844 
845 bus_dmaengine_t
846 ioat_get_dmaengine(uint32_t index, int flags)
847 {
848 	struct ioat_softc *ioat;
849 
850 	KASSERT((flags & ~(M_NOWAIT | M_WAITOK)) == 0,
851 	    ("invalid flags: 0x%08x", flags));
852 	KASSERT((flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK),
853 	    ("invalid wait | nowait"));
854 
855 	if (index >= ioat_channel_index)
856 		return (NULL);
857 
858 	ioat = ioat_channel[index];
859 	if (ioat == NULL || ioat->destroying)
860 		return (NULL);
861 
862 	if (ioat->quiescing) {
863 		if ((flags & M_NOWAIT) != 0)
864 			return (NULL);
865 
866 		mtx_lock(IOAT_REFLK);
867 		while (ioat->quiescing && !ioat->destroying)
868 			msleep(&ioat->quiescing, IOAT_REFLK, 0, "getdma", 0);
869 		mtx_unlock(IOAT_REFLK);
870 
871 		if (ioat->destroying)
872 			return (NULL);
873 	}
874 
875 	/*
876 	 * There's a race here between the quiescing check and HW reset or
877 	 * module destroy.
878 	 */
879 	return (&ioat_get(ioat, IOAT_DMAENGINE_REF)->dmaengine);
880 }
881 
882 void
883 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
884 {
885 	struct ioat_softc *ioat;
886 
887 	ioat = to_ioat_softc(dmaengine);
888 	ioat_put(ioat, IOAT_DMAENGINE_REF);
889 }
890 
891 int
892 ioat_get_hwversion(bus_dmaengine_t dmaengine)
893 {
894 	struct ioat_softc *ioat;
895 
896 	ioat = to_ioat_softc(dmaengine);
897 	return (ioat->version);
898 }
899 
900 size_t
901 ioat_get_max_io_size(bus_dmaengine_t dmaengine)
902 {
903 	struct ioat_softc *ioat;
904 
905 	ioat = to_ioat_softc(dmaengine);
906 	return (ioat->max_xfer_size);
907 }
908 
909 uint32_t
910 ioat_get_capabilities(bus_dmaengine_t dmaengine)
911 {
912 	struct ioat_softc *ioat;
913 
914 	ioat = to_ioat_softc(dmaengine);
915 	return (ioat->capabilities);
916 }
917 
918 int
919 ioat_set_interrupt_coalesce(bus_dmaengine_t dmaengine, uint16_t delay)
920 {
921 	struct ioat_softc *ioat;
922 
923 	ioat = to_ioat_softc(dmaengine);
924 	if (!ioat->intrdelay_supported)
925 		return (ENODEV);
926 	if (delay > ioat->intrdelay_max)
927 		return (ERANGE);
928 
929 	ioat_write_2(ioat, IOAT_INTRDELAY_OFFSET, delay);
930 	ioat->cached_intrdelay =
931 	    ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) & IOAT_INTRDELAY_US_MASK;
932 	return (0);
933 }
934 
935 uint16_t
936 ioat_get_max_coalesce_period(bus_dmaengine_t dmaengine)
937 {
938 	struct ioat_softc *ioat;
939 
940 	ioat = to_ioat_softc(dmaengine);
941 	return (ioat->intrdelay_max);
942 }
943 
944 void
945 ioat_acquire(bus_dmaengine_t dmaengine)
946 {
947 	struct ioat_softc *ioat;
948 
949 	ioat = to_ioat_softc(dmaengine);
950 	mtx_lock(&ioat->submit_lock);
951 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
952 	ioat->acq_head = ioat->head;
953 }
954 
955 int
956 ioat_acquire_reserve(bus_dmaengine_t dmaengine, unsigned n, int mflags)
957 {
958 	struct ioat_softc *ioat;
959 	int error;
960 
961 	ioat = to_ioat_softc(dmaengine);
962 	ioat_acquire(dmaengine);
963 
964 	error = ioat_reserve_space(ioat, n, mflags);
965 	if (error != 0)
966 		ioat_release(dmaengine);
967 	return (error);
968 }
969 
970 void
971 ioat_release(bus_dmaengine_t dmaengine)
972 {
973 	struct ioat_softc *ioat;
974 
975 	ioat = to_ioat_softc(dmaengine);
976 	CTR4(KTR_IOAT, "%s channel=%u dispatch1 hw_head=%u head=%u", __func__,
977 	    ioat->chan_idx, ioat->hw_head & UINT16_MAX, ioat->head);
978 	KFAIL_POINT_CODE(DEBUG_FP, ioat_release, /* do nothing */);
979 	CTR4(KTR_IOAT, "%s channel=%u dispatch2 hw_head=%u head=%u", __func__,
980 	    ioat->chan_idx, ioat->hw_head & UINT16_MAX, ioat->head);
981 
982 	if (ioat->acq_head != ioat->head) {
983 		ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET,
984 		    (uint16_t)ioat->hw_head);
985 
986 		if (!ioat->is_completion_pending) {
987 			ioat->is_completion_pending = TRUE;
988 			callout_reset(&ioat->poll_timer, 1,
989 			    ioat_poll_timer_callback, ioat);
990 		}
991 	}
992 	mtx_unlock(&ioat->submit_lock);
993 }
994 
995 static struct ioat_descriptor *
996 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
997     uint32_t size, uint64_t src, uint64_t dst,
998     bus_dmaengine_callback_t callback_fn, void *callback_arg,
999     uint32_t flags)
1000 {
1001 	struct ioat_generic_hw_descriptor *hw_desc;
1002 	struct ioat_descriptor *desc;
1003 	int mflags;
1004 
1005 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1006 
1007 	KASSERT((flags & ~_DMA_GENERIC_FLAGS) == 0,
1008 	    ("Unrecognized flag(s): %#x", flags & ~_DMA_GENERIC_FLAGS));
1009 	if ((flags & DMA_NO_WAIT) != 0)
1010 		mflags = M_NOWAIT;
1011 	else
1012 		mflags = M_WAITOK;
1013 
1014 	if (size > ioat->max_xfer_size) {
1015 		ioat_log_message(0, "%s: max_xfer_size = %d, requested = %u\n",
1016 		    __func__, ioat->max_xfer_size, (unsigned)size);
1017 		return (NULL);
1018 	}
1019 
1020 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
1021 		return (NULL);
1022 
1023 	desc = ioat_get_ring_entry(ioat, ioat->head);
1024 	hw_desc = &ioat_get_descriptor(ioat, ioat->head)->generic;
1025 
1026 	hw_desc->u.control_raw = 0;
1027 	hw_desc->u.control_generic.op = op;
1028 	hw_desc->u.control_generic.completion_update = 1;
1029 
1030 	if ((flags & DMA_INT_EN) != 0)
1031 		hw_desc->u.control_generic.int_enable = 1;
1032 	if ((flags & DMA_FENCE) != 0)
1033 		hw_desc->u.control_generic.fence = 1;
1034 
1035 	hw_desc->size = size;
1036 	hw_desc->src_addr = src;
1037 	hw_desc->dest_addr = dst;
1038 
1039 	desc->bus_dmadesc.callback_fn = callback_fn;
1040 	desc->bus_dmadesc.callback_arg = callback_arg;
1041 	return (desc);
1042 }
1043 
1044 struct bus_dmadesc *
1045 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
1046     void *callback_arg, uint32_t flags)
1047 {
1048 	struct ioat_dma_hw_descriptor *hw_desc;
1049 	struct ioat_descriptor *desc;
1050 	struct ioat_softc *ioat;
1051 
1052 	ioat = to_ioat_softc(dmaengine);
1053 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1054 
1055 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
1056 	    callback_arg, flags);
1057 	if (desc == NULL)
1058 		return (NULL);
1059 
1060 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1061 	hw_desc->u.control.null = 1;
1062 	ioat_submit_single(ioat);
1063 	return (&desc->bus_dmadesc);
1064 }
1065 
1066 struct bus_dmadesc *
1067 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
1068     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
1069     void *callback_arg, uint32_t flags)
1070 {
1071 	struct ioat_dma_hw_descriptor *hw_desc;
1072 	struct ioat_descriptor *desc;
1073 	struct ioat_softc *ioat;
1074 
1075 	ioat = to_ioat_softc(dmaengine);
1076 
1077 	if (((src | dst) & (0xffffull << 48)) != 0) {
1078 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1079 		    __func__);
1080 		return (NULL);
1081 	}
1082 
1083 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
1084 	    callback_arg, flags);
1085 	if (desc == NULL)
1086 		return (NULL);
1087 
1088 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1089 	if (g_ioat_debug_level >= 3)
1090 		dump_descriptor(hw_desc);
1091 
1092 	ioat_submit_single(ioat);
1093 	CTR6(KTR_IOAT, "%s channel=%u desc=%p dest=%lx src=%lx len=%lx",
1094 	    __func__, ioat->chan_idx, &desc->bus_dmadesc, dst, src, len);
1095 	return (&desc->bus_dmadesc);
1096 }
1097 
1098 struct bus_dmadesc *
1099 ioat_copy_8k_aligned(bus_dmaengine_t dmaengine, bus_addr_t dst1,
1100     bus_addr_t dst2, bus_addr_t src1, bus_addr_t src2,
1101     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1102 {
1103 	struct ioat_dma_hw_descriptor *hw_desc;
1104 	struct ioat_descriptor *desc;
1105 	struct ioat_softc *ioat;
1106 
1107 	ioat = to_ioat_softc(dmaengine);
1108 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1109 
1110 	if (((src1 | src2 | dst1 | dst2) & (0xffffull << 48)) != 0) {
1111 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1112 		    __func__);
1113 		return (NULL);
1114 	}
1115 	if (((src1 | src2 | dst1 | dst2) & PAGE_MASK) != 0) {
1116 		ioat_log_message(0, "%s: Addresses must be page-aligned\n",
1117 		    __func__);
1118 		return (NULL);
1119 	}
1120 
1121 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 2 * PAGE_SIZE, src1, dst1,
1122 	    callback_fn, callback_arg, flags);
1123 	if (desc == NULL)
1124 		return (NULL);
1125 
1126 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1127 	if (src2 != src1 + PAGE_SIZE) {
1128 		hw_desc->u.control.src_page_break = 1;
1129 		hw_desc->next_src_addr = src2;
1130 	}
1131 	if (dst2 != dst1 + PAGE_SIZE) {
1132 		hw_desc->u.control.dest_page_break = 1;
1133 		hw_desc->next_dest_addr = dst2;
1134 	}
1135 
1136 	if (g_ioat_debug_level >= 3)
1137 		dump_descriptor(hw_desc);
1138 
1139 	ioat_submit_single(ioat);
1140 	return (&desc->bus_dmadesc);
1141 }
1142 
1143 struct bus_dmadesc *
1144 ioat_copy_crc(bus_dmaengine_t dmaengine, bus_addr_t dst, bus_addr_t src,
1145     bus_size_t len, uint32_t *initialseed, bus_addr_t crcptr,
1146     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1147 {
1148 	struct ioat_crc32_hw_descriptor *hw_desc;
1149 	struct ioat_descriptor *desc;
1150 	struct ioat_softc *ioat;
1151 	uint32_t teststore;
1152 	uint8_t op;
1153 
1154 	ioat = to_ioat_softc(dmaengine);
1155 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1156 
1157 	if ((ioat->capabilities & IOAT_DMACAP_MOVECRC) == 0) {
1158 		ioat_log_message(0, "%s: Device lacks MOVECRC capability\n",
1159 		    __func__);
1160 		return (NULL);
1161 	}
1162 	if (((src | dst) & (0xffffffull << 40)) != 0) {
1163 		ioat_log_message(0, "%s: High 24 bits of src/dst invalid\n",
1164 		    __func__);
1165 		return (NULL);
1166 	}
1167 	teststore = (flags & _DMA_CRC_TESTSTORE);
1168 	if (teststore == _DMA_CRC_TESTSTORE) {
1169 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1170 		return (NULL);
1171 	}
1172 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1173 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1174 		    __func__);
1175 		return (NULL);
1176 	}
1177 
1178 	switch (teststore) {
1179 	case DMA_CRC_STORE:
1180 		op = IOAT_OP_MOVECRC_STORE;
1181 		break;
1182 	case DMA_CRC_TEST:
1183 		op = IOAT_OP_MOVECRC_TEST;
1184 		break;
1185 	default:
1186 		KASSERT(teststore == 0, ("bogus"));
1187 		op = IOAT_OP_MOVECRC;
1188 		break;
1189 	}
1190 
1191 	if ((flags & DMA_CRC_INLINE) == 0 &&
1192 	    (crcptr & (0xffffffull << 40)) != 0) {
1193 		ioat_log_message(0,
1194 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1195 		return (NULL);
1196 	}
1197 
1198 	desc = ioat_op_generic(ioat, op, len, src, dst, callback_fn,
1199 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1200 	if (desc == NULL)
1201 		return (NULL);
1202 
1203 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1204 
1205 	if ((flags & DMA_CRC_INLINE) == 0)
1206 		hw_desc->crc_address = crcptr;
1207 	else
1208 		hw_desc->u.control.crc_location = 1;
1209 
1210 	if (initialseed != NULL) {
1211 		hw_desc->u.control.use_seed = 1;
1212 		hw_desc->seed = *initialseed;
1213 	}
1214 
1215 	if (g_ioat_debug_level >= 3)
1216 		dump_descriptor(hw_desc);
1217 
1218 	ioat_submit_single(ioat);
1219 	return (&desc->bus_dmadesc);
1220 }
1221 
1222 struct bus_dmadesc *
1223 ioat_crc(bus_dmaengine_t dmaengine, bus_addr_t src, bus_size_t len,
1224     uint32_t *initialseed, bus_addr_t crcptr,
1225     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1226 {
1227 	struct ioat_crc32_hw_descriptor *hw_desc;
1228 	struct ioat_descriptor *desc;
1229 	struct ioat_softc *ioat;
1230 	uint32_t teststore;
1231 	uint8_t op;
1232 
1233 	ioat = to_ioat_softc(dmaengine);
1234 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1235 
1236 	if ((ioat->capabilities & IOAT_DMACAP_CRC) == 0) {
1237 		ioat_log_message(0, "%s: Device lacks CRC capability\n",
1238 		    __func__);
1239 		return (NULL);
1240 	}
1241 	if ((src & (0xffffffull << 40)) != 0) {
1242 		ioat_log_message(0, "%s: High 24 bits of src invalid\n",
1243 		    __func__);
1244 		return (NULL);
1245 	}
1246 	teststore = (flags & _DMA_CRC_TESTSTORE);
1247 	if (teststore == _DMA_CRC_TESTSTORE) {
1248 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1249 		return (NULL);
1250 	}
1251 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1252 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1253 		    __func__);
1254 		return (NULL);
1255 	}
1256 
1257 	switch (teststore) {
1258 	case DMA_CRC_STORE:
1259 		op = IOAT_OP_CRC_STORE;
1260 		break;
1261 	case DMA_CRC_TEST:
1262 		op = IOAT_OP_CRC_TEST;
1263 		break;
1264 	default:
1265 		KASSERT(teststore == 0, ("bogus"));
1266 		op = IOAT_OP_CRC;
1267 		break;
1268 	}
1269 
1270 	if ((flags & DMA_CRC_INLINE) == 0 &&
1271 	    (crcptr & (0xffffffull << 40)) != 0) {
1272 		ioat_log_message(0,
1273 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1274 		return (NULL);
1275 	}
1276 
1277 	desc = ioat_op_generic(ioat, op, len, src, 0, callback_fn,
1278 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1279 	if (desc == NULL)
1280 		return (NULL);
1281 
1282 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1283 
1284 	if ((flags & DMA_CRC_INLINE) == 0)
1285 		hw_desc->crc_address = crcptr;
1286 	else
1287 		hw_desc->u.control.crc_location = 1;
1288 
1289 	if (initialseed != NULL) {
1290 		hw_desc->u.control.use_seed = 1;
1291 		hw_desc->seed = *initialseed;
1292 	}
1293 
1294 	if (g_ioat_debug_level >= 3)
1295 		dump_descriptor(hw_desc);
1296 
1297 	ioat_submit_single(ioat);
1298 	return (&desc->bus_dmadesc);
1299 }
1300 
1301 struct bus_dmadesc *
1302 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
1303     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
1304     uint32_t flags)
1305 {
1306 	struct ioat_fill_hw_descriptor *hw_desc;
1307 	struct ioat_descriptor *desc;
1308 	struct ioat_softc *ioat;
1309 
1310 	ioat = to_ioat_softc(dmaengine);
1311 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1312 
1313 	if ((ioat->capabilities & IOAT_DMACAP_BFILL) == 0) {
1314 		ioat_log_message(0, "%s: Device lacks BFILL capability\n",
1315 		    __func__);
1316 		return (NULL);
1317 	}
1318 
1319 	if ((dst & (0xffffull << 48)) != 0) {
1320 		ioat_log_message(0, "%s: High 16 bits of dst invalid\n",
1321 		    __func__);
1322 		return (NULL);
1323 	}
1324 
1325 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, fillpattern, dst,
1326 	    callback_fn, callback_arg, flags);
1327 	if (desc == NULL)
1328 		return (NULL);
1329 
1330 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->fill;
1331 	if (g_ioat_debug_level >= 3)
1332 		dump_descriptor(hw_desc);
1333 
1334 	ioat_submit_single(ioat);
1335 	return (&desc->bus_dmadesc);
1336 }
1337 
1338 /*
1339  * Ring Management
1340  */
1341 static inline uint32_t
1342 ioat_get_active(struct ioat_softc *ioat)
1343 {
1344 
1345 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
1346 }
1347 
1348 static inline uint32_t
1349 ioat_get_ring_space(struct ioat_softc *ioat)
1350 {
1351 
1352 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
1353 }
1354 
1355 /*
1356  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
1357  * for 'num_descs'.
1358  *
1359  * If mflags contains M_WAITOK, blocks until enough space is available.
1360  *
1361  * Returns zero on success, or an errno on error.  If num_descs is beyond the
1362  * maximum ring size, returns EINVAl; if allocation would block and mflags
1363  * contains M_NOWAIT, returns EAGAIN.
1364  *
1365  * Must be called with the submit_lock held; returns with the lock held.  The
1366  * lock may be dropped to allocate the ring.
1367  *
1368  * (The submit_lock is needed to add any entries to the ring, so callers are
1369  * assured enough room is available.)
1370  */
1371 static int
1372 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
1373 {
1374 	boolean_t dug;
1375 	int error;
1376 
1377 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1378 	error = 0;
1379 	dug = FALSE;
1380 
1381 	if (num_descs < 1 || num_descs >= (1 << ioat->ring_size_order)) {
1382 		error = EINVAL;
1383 		goto out;
1384 	}
1385 
1386 	for (;;) {
1387 		if (ioat->quiescing) {
1388 			error = ENXIO;
1389 			goto out;
1390 		}
1391 
1392 		if (ioat_get_ring_space(ioat) >= num_descs)
1393 			goto out;
1394 
1395 		CTR3(KTR_IOAT, "%s channel=%u starved (%u)", __func__,
1396 		    ioat->chan_idx, num_descs);
1397 
1398 		if (!dug && !ioat->is_submitter_processing) {
1399 			ioat->is_submitter_processing = TRUE;
1400 			mtx_unlock(&ioat->submit_lock);
1401 
1402 			CTR2(KTR_IOAT, "%s channel=%u attempting to process events",
1403 			    __func__, ioat->chan_idx);
1404 			ioat_process_events(ioat);
1405 
1406 			mtx_lock(&ioat->submit_lock);
1407 			dug = TRUE;
1408 			KASSERT(ioat->is_submitter_processing == TRUE,
1409 			    ("is_submitter_processing"));
1410 			ioat->is_submitter_processing = FALSE;
1411 			wakeup(&ioat->tail);
1412 			continue;
1413 		}
1414 
1415 		if ((mflags & M_WAITOK) == 0) {
1416 			error = EAGAIN;
1417 			break;
1418 		}
1419 		CTR2(KTR_IOAT, "%s channel=%u blocking on completions",
1420 		    __func__, ioat->chan_idx);
1421 		msleep(&ioat->tail, &ioat->submit_lock, 0,
1422 		    "ioat_full", 0);
1423 		continue;
1424 	}
1425 
1426 out:
1427 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1428 	KASSERT(!ioat->quiescing || error == ENXIO,
1429 	    ("reserved during quiesce"));
1430 	return (error);
1431 }
1432 
1433 static void
1434 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1435     struct ioat_descriptor *ring)
1436 {
1437 
1438 	free(ring, M_IOAT);
1439 }
1440 
1441 static struct ioat_descriptor *
1442 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1443 {
1444 
1445 	return (&ioat->ring[index % (1 << ioat->ring_size_order)]);
1446 }
1447 
1448 static union ioat_hw_descriptor *
1449 ioat_get_descriptor(struct ioat_softc *ioat, uint32_t index)
1450 {
1451 
1452 	return (&ioat->hw_desc_ring[index % (1 << ioat->ring_size_order)]);
1453 }
1454 
1455 static void
1456 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1457 {
1458 	union ioat_hw_descriptor *desc;
1459 
1460 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1461 	    IOAT_CHANERR_STR);
1462 	if (chanerr == 0)
1463 		return;
1464 
1465 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1466 
1467 	desc = ioat_get_descriptor(ioat, ioat->tail + 0);
1468 	dump_descriptor(desc);
1469 
1470 	desc = ioat_get_descriptor(ioat, ioat->tail + 1);
1471 	dump_descriptor(desc);
1472 }
1473 
1474 static void
1475 ioat_poll_timer_callback(void *arg)
1476 {
1477 	struct ioat_softc *ioat;
1478 
1479 	ioat = arg;
1480 	ioat_log_message(3, "%s\n", __func__);
1481 
1482 	ioat_process_events(ioat);
1483 }
1484 
1485 /*
1486  * Support Functions
1487  */
1488 static void
1489 ioat_submit_single(struct ioat_softc *ioat)
1490 {
1491 
1492 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1493 
1494 	ioat_get(ioat, IOAT_ACTIVE_DESCR_REF);
1495 	atomic_add_rel_int(&ioat->head, 1);
1496 	atomic_add_rel_int(&ioat->hw_head, 1);
1497 	CTR5(KTR_IOAT, "%s channel=%u head=%u hw_head=%u tail=%u", __func__,
1498 	    ioat->chan_idx, ioat->head, ioat->hw_head & UINT16_MAX,
1499 	    ioat->tail);
1500 
1501 	ioat->stats.descriptors_submitted++;
1502 }
1503 
1504 static int
1505 ioat_reset_hw(struct ioat_softc *ioat)
1506 {
1507 	uint64_t status;
1508 	uint32_t chanerr;
1509 	unsigned timeout;
1510 	int error;
1511 
1512 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1513 
1514 	mtx_lock(IOAT_REFLK);
1515 	while (ioat->resetting && !ioat->destroying)
1516 		msleep(&ioat->resetting, IOAT_REFLK, 0, "IRH_drain", 0);
1517 	if (ioat->destroying) {
1518 		mtx_unlock(IOAT_REFLK);
1519 		return (ENXIO);
1520 	}
1521 	ioat->resetting = TRUE;
1522 
1523 	ioat->quiescing = TRUE;
1524 	ioat_drain_locked(ioat);
1525 	mtx_unlock(IOAT_REFLK);
1526 
1527 	/*
1528 	 * Suspend ioat_process_events while the hardware and softc are in an
1529 	 * indeterminate state.
1530 	 */
1531 	mtx_lock(&ioat->cleanup_lock);
1532 	ioat->resetting_cleanup = TRUE;
1533 	mtx_unlock(&ioat->cleanup_lock);
1534 
1535 	CTR2(KTR_IOAT, "%s channel=%u quiesced and drained", __func__,
1536 	    ioat->chan_idx);
1537 
1538 	status = ioat_get_chansts(ioat);
1539 	if (is_ioat_active(status) || is_ioat_idle(status))
1540 		ioat_suspend(ioat);
1541 
1542 	/* Wait at most 20 ms */
1543 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1544 	    timeout < 20; timeout++) {
1545 		DELAY(1000);
1546 		status = ioat_get_chansts(ioat);
1547 	}
1548 	if (timeout == 20) {
1549 		error = ETIMEDOUT;
1550 		goto out;
1551 	}
1552 
1553 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1554 
1555 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1556 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1557 
1558 	CTR2(KTR_IOAT, "%s channel=%u hardware suspended", __func__,
1559 	    ioat->chan_idx);
1560 
1561 	/*
1562 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1563 	 *  that can cause stability issues for IOAT v3.
1564 	 */
1565 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1566 	    4);
1567 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1568 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1569 
1570 	/*
1571 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1572 	 * Save/restore their contents manually.
1573 	 */
1574 	if (ioat_model_resets_msix(ioat)) {
1575 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1576 		pci_save_state(ioat->device);
1577 	}
1578 
1579 	ioat_reset(ioat);
1580 	CTR2(KTR_IOAT, "%s channel=%u hardware reset", __func__,
1581 	    ioat->chan_idx);
1582 
1583 	/* Wait at most 20 ms */
1584 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1585 		DELAY(1000);
1586 	if (timeout == 20) {
1587 		error = ETIMEDOUT;
1588 		goto out;
1589 	}
1590 
1591 	if (ioat_model_resets_msix(ioat)) {
1592 		ioat_log_message(1, "device resets registers; restored\n");
1593 		pci_restore_state(ioat->device);
1594 	}
1595 
1596 	/* Reset attempts to return the hardware to "halted." */
1597 	status = ioat_get_chansts(ioat);
1598 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1599 		/* So this really shouldn't happen... */
1600 		ioat_log_message(0, "Device is active after a reset?\n");
1601 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1602 		error = 0;
1603 		goto out;
1604 	}
1605 
1606 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1607 	if (chanerr != 0) {
1608 		mtx_lock(&ioat->cleanup_lock);
1609 		ioat_halted_debug(ioat, chanerr);
1610 		mtx_unlock(&ioat->cleanup_lock);
1611 		error = EIO;
1612 		goto out;
1613 	}
1614 
1615 	/*
1616 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1617 	 * device back to active.
1618 	 *
1619 	 * The internal ring counter resets to zero, so we have to start over
1620 	 * at zero as well.
1621 	 */
1622 	ioat->tail = ioat->head = ioat->hw_head = 0;
1623 	ioat->last_seen = 0;
1624 	*ioat->comp_update = 0;
1625 	KASSERT(!ioat->is_completion_pending, ("bogus completion_pending"));
1626 
1627 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1628 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1629 	ioat_write_chainaddr(ioat, RING_PHYS_ADDR(ioat, 0));
1630 	error = 0;
1631 	CTR2(KTR_IOAT, "%s channel=%u configured channel", __func__,
1632 	    ioat->chan_idx);
1633 
1634 out:
1635 	/* Enqueues a null operation and ensures it completes. */
1636 	if (error == 0) {
1637 		error = ioat_start_channel(ioat);
1638 		CTR2(KTR_IOAT, "%s channel=%u started channel", __func__,
1639 		    ioat->chan_idx);
1640 	}
1641 
1642 	/*
1643 	 * Resume completions now that ring state is consistent.
1644 	 */
1645 	mtx_lock(&ioat->cleanup_lock);
1646 	ioat->resetting_cleanup = FALSE;
1647 	mtx_unlock(&ioat->cleanup_lock);
1648 
1649 	/* Unblock submission of new work */
1650 	mtx_lock(IOAT_REFLK);
1651 	ioat->quiescing = FALSE;
1652 	wakeup(&ioat->quiescing);
1653 
1654 	ioat->resetting = FALSE;
1655 	wakeup(&ioat->resetting);
1656 
1657 	if (ioat->is_completion_pending)
1658 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
1659 		    ioat);
1660 	CTR2(KTR_IOAT, "%s channel=%u reset done", __func__, ioat->chan_idx);
1661 	mtx_unlock(IOAT_REFLK);
1662 
1663 	return (error);
1664 }
1665 
1666 static int
1667 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1668 {
1669 	struct ioat_softc *ioat;
1670 	struct sbuf sb;
1671 	uint64_t status;
1672 	int error;
1673 
1674 	ioat = arg1;
1675 
1676 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1677 
1678 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1679 	switch (status) {
1680 	case IOAT_CHANSTS_ACTIVE:
1681 		sbuf_printf(&sb, "ACTIVE");
1682 		break;
1683 	case IOAT_CHANSTS_IDLE:
1684 		sbuf_printf(&sb, "IDLE");
1685 		break;
1686 	case IOAT_CHANSTS_SUSPENDED:
1687 		sbuf_printf(&sb, "SUSPENDED");
1688 		break;
1689 	case IOAT_CHANSTS_HALTED:
1690 		sbuf_printf(&sb, "HALTED");
1691 		break;
1692 	case IOAT_CHANSTS_ARMED:
1693 		sbuf_printf(&sb, "ARMED");
1694 		break;
1695 	default:
1696 		sbuf_printf(&sb, "UNKNOWN");
1697 		break;
1698 	}
1699 	error = sbuf_finish(&sb);
1700 	sbuf_delete(&sb);
1701 
1702 	if (error != 0 || req->newptr == NULL)
1703 		return (error);
1704 	return (EINVAL);
1705 }
1706 
1707 static int
1708 sysctl_handle_dpi(SYSCTL_HANDLER_ARGS)
1709 {
1710 	struct ioat_softc *ioat;
1711 	struct sbuf sb;
1712 #define	PRECISION	"1"
1713 	const uintmax_t factor = 10;
1714 	uintmax_t rate;
1715 	int error;
1716 
1717 	ioat = arg1;
1718 	sbuf_new_for_sysctl(&sb, NULL, 16, req);
1719 
1720 	if (ioat->stats.interrupts == 0) {
1721 		sbuf_printf(&sb, "NaN");
1722 		goto out;
1723 	}
1724 	rate = ioat->stats.descriptors_processed * factor /
1725 	    ioat->stats.interrupts;
1726 	sbuf_printf(&sb, "%ju.%." PRECISION "ju", rate / factor,
1727 	    rate % factor);
1728 #undef	PRECISION
1729 out:
1730 	error = sbuf_finish(&sb);
1731 	sbuf_delete(&sb);
1732 	if (error != 0 || req->newptr == NULL)
1733 		return (error);
1734 	return (EINVAL);
1735 }
1736 
1737 static int
1738 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
1739 {
1740 	struct ioat_softc *ioat;
1741 	int error, arg;
1742 
1743 	ioat = arg1;
1744 
1745 	arg = 0;
1746 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1747 	if (error != 0 || req->newptr == NULL)
1748 		return (error);
1749 
1750 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1751 	if (error != 0)
1752 		return (error);
1753 
1754 	if (arg != 0)
1755 		error = ioat_reset_hw(ioat);
1756 
1757 	return (error);
1758 }
1759 
1760 static void
1761 dump_descriptor(void *hw_desc)
1762 {
1763 	int i, j;
1764 
1765 	for (i = 0; i < 2; i++) {
1766 		for (j = 0; j < 8; j++)
1767 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
1768 		printf("\n");
1769 	}
1770 }
1771 
1772 static void
1773 ioat_setup_sysctl(device_t device)
1774 {
1775 	struct sysctl_oid_list *par, *statpar, *state, *hammer;
1776 	struct sysctl_ctx_list *ctx;
1777 	struct sysctl_oid *tree, *tmp;
1778 	struct ioat_softc *ioat;
1779 
1780 	ioat = DEVICE2SOFTC(device);
1781 	ctx = device_get_sysctl_ctx(device);
1782 	tree = device_get_sysctl_tree(device);
1783 	par = SYSCTL_CHILDREN(tree);
1784 
1785 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
1786 	    &ioat->version, 0, "HW version (0xMM form)");
1787 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
1788 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
1789 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "intrdelay_supported", CTLFLAG_RD,
1790 	    &ioat->intrdelay_supported, 0, "Is INTRDELAY supported");
1791 	SYSCTL_ADD_U16(ctx, par, OID_AUTO, "intrdelay_max", CTLFLAG_RD,
1792 	    &ioat->intrdelay_max, 0,
1793 	    "Maximum configurable INTRDELAY on this channel (microseconds)");
1794 
1795 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "state", CTLFLAG_RD, NULL,
1796 	    "IOAT channel internal state");
1797 	state = SYSCTL_CHILDREN(tmp);
1798 
1799 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "ring_size_order", CTLFLAG_RD,
1800 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
1801 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "head", CTLFLAG_RD, &ioat->head,
1802 	    0, "SW descriptor head pointer index");
1803 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail,
1804 	    0, "SW descriptor tail pointer index");
1805 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "hw_head", CTLFLAG_RD,
1806 	    &ioat->hw_head, 0, "HW DMACOUNT");
1807 
1808 	SYSCTL_ADD_UQUAD(ctx, state, OID_AUTO, "last_completion", CTLFLAG_RD,
1809 	    ioat->comp_update, "HW addr of last completion");
1810 
1811 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_submitter_processing",
1812 	    CTLFLAG_RD, &ioat->is_submitter_processing, 0,
1813 	    "submitter processing");
1814 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_completion_pending",
1815 	    CTLFLAG_RD, &ioat->is_completion_pending, 0, "completion pending");
1816 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_reset_pending", CTLFLAG_RD,
1817 	    &ioat->is_reset_pending, 0, "reset pending");
1818 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_channel_running", CTLFLAG_RD,
1819 	    &ioat->is_channel_running, 0, "channel running");
1820 
1821 	SYSCTL_ADD_PROC(ctx, state, OID_AUTO, "chansts",
1822 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
1823 	    "String of the channel status");
1824 
1825 	SYSCTL_ADD_U16(ctx, state, OID_AUTO, "intrdelay", CTLFLAG_RD,
1826 	    &ioat->cached_intrdelay, 0,
1827 	    "Current INTRDELAY on this channel (cached, microseconds)");
1828 
1829 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "hammer", CTLFLAG_RD, NULL,
1830 	    "Big hammers (mostly for testing)");
1831 	hammer = SYSCTL_CHILDREN(tmp);
1832 
1833 	SYSCTL_ADD_PROC(ctx, hammer, OID_AUTO, "force_hw_reset",
1834 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
1835 	    "Set to non-zero to reset the hardware");
1836 
1837 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "stats", CTLFLAG_RD, NULL,
1838 	    "IOAT channel statistics");
1839 	statpar = SYSCTL_CHILDREN(tmp);
1840 
1841 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "interrupts", CTLFLAG_RW,
1842 	    &ioat->stats.interrupts,
1843 	    "Number of interrupts processed on this channel");
1844 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "descriptors", CTLFLAG_RW,
1845 	    &ioat->stats.descriptors_processed,
1846 	    "Number of descriptors processed on this channel");
1847 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "submitted", CTLFLAG_RW,
1848 	    &ioat->stats.descriptors_submitted,
1849 	    "Number of descriptors submitted to this channel");
1850 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "errored", CTLFLAG_RW,
1851 	    &ioat->stats.descriptors_error,
1852 	    "Number of descriptors failed by channel errors");
1853 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "halts", CTLFLAG_RW,
1854 	    &ioat->stats.channel_halts, 0,
1855 	    "Number of times the channel has halted");
1856 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "last_halt_chanerr", CTLFLAG_RW,
1857 	    &ioat->stats.last_halt_chanerr, 0,
1858 	    "The raw CHANERR when the channel was last halted");
1859 
1860 	SYSCTL_ADD_PROC(ctx, statpar, OID_AUTO, "desc_per_interrupt",
1861 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_dpi, "A",
1862 	    "Descriptors per interrupt");
1863 }
1864 
1865 static inline struct ioat_softc *
1866 ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1867 {
1868 	uint32_t old;
1869 
1870 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1871 
1872 	old = atomic_fetchadd_32(&ioat->refcnt, 1);
1873 	KASSERT(old < UINT32_MAX, ("refcnt overflow"));
1874 
1875 #ifdef INVARIANTS
1876 	old = atomic_fetchadd_32(&ioat->refkinds[kind], 1);
1877 	KASSERT(old < UINT32_MAX, ("refcnt kind overflow"));
1878 #endif
1879 
1880 	return (ioat);
1881 }
1882 
1883 static inline void
1884 ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1885 {
1886 
1887 	_ioat_putn(ioat, n, kind, FALSE);
1888 }
1889 
1890 static inline void
1891 ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1892 {
1893 
1894 	_ioat_putn(ioat, n, kind, TRUE);
1895 }
1896 
1897 static inline void
1898 _ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
1899     boolean_t locked)
1900 {
1901 	uint32_t old;
1902 
1903 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1904 
1905 	if (n == 0)
1906 		return;
1907 
1908 #ifdef INVARIANTS
1909 	old = atomic_fetchadd_32(&ioat->refkinds[kind], -n);
1910 	KASSERT(old >= n, ("refcnt kind underflow"));
1911 #endif
1912 
1913 	/* Skip acquiring the lock if resulting refcnt > 0. */
1914 	for (;;) {
1915 		old = ioat->refcnt;
1916 		if (old <= n)
1917 			break;
1918 		if (atomic_cmpset_32(&ioat->refcnt, old, old - n))
1919 			return;
1920 	}
1921 
1922 	if (locked)
1923 		mtx_assert(IOAT_REFLK, MA_OWNED);
1924 	else
1925 		mtx_lock(IOAT_REFLK);
1926 
1927 	old = atomic_fetchadd_32(&ioat->refcnt, -n);
1928 	KASSERT(old >= n, ("refcnt error"));
1929 
1930 	if (old == n)
1931 		wakeup(IOAT_REFLK);
1932 	if (!locked)
1933 		mtx_unlock(IOAT_REFLK);
1934 }
1935 
1936 static inline void
1937 ioat_put(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1938 {
1939 
1940 	ioat_putn(ioat, 1, kind);
1941 }
1942 
1943 static void
1944 ioat_drain_locked(struct ioat_softc *ioat)
1945 {
1946 
1947 	mtx_assert(IOAT_REFLK, MA_OWNED);
1948 	while (ioat->refcnt > 0)
1949 		msleep(IOAT_REFLK, IOAT_REFLK, 0, "ioat_drain", 0);
1950 }
1951 
1952 #ifdef DDB
1953 #define	_db_show_lock(lo)	LOCK_CLASS(lo)->lc_ddb_show(lo)
1954 #define	db_show_lock(lk)	_db_show_lock(&(lk)->lock_object)
1955 DB_SHOW_COMMAND(ioat, db_show_ioat)
1956 {
1957 	struct ioat_softc *sc;
1958 	unsigned idx;
1959 
1960 	if (!have_addr)
1961 		goto usage;
1962 	idx = (unsigned)addr;
1963 	if (idx >= ioat_channel_index)
1964 		goto usage;
1965 
1966 	sc = ioat_channel[idx];
1967 	db_printf("ioat softc at %p\n", sc);
1968 	if (sc == NULL)
1969 		return;
1970 
1971 	db_printf(" version: %d\n", sc->version);
1972 	db_printf(" chan_idx: %u\n", sc->chan_idx);
1973 	db_printf(" submit_lock: ");
1974 	db_show_lock(&sc->submit_lock);
1975 
1976 	db_printf(" capabilities: %b\n", (int)sc->capabilities,
1977 	    IOAT_DMACAP_STR);
1978 	db_printf(" cached_intrdelay: %u\n", sc->cached_intrdelay);
1979 	db_printf(" *comp_update: 0x%jx\n", (uintmax_t)*sc->comp_update);
1980 
1981 	db_printf(" poll_timer:\n");
1982 	db_printf("  c_time: %ju\n", (uintmax_t)sc->poll_timer.c_time);
1983 	db_printf("  c_arg: %p\n", sc->poll_timer.c_arg);
1984 	db_printf("  c_func: %p\n", sc->poll_timer.c_func);
1985 	db_printf("  c_lock: %p\n", sc->poll_timer.c_lock);
1986 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->poll_timer.c_flags);
1987 
1988 	db_printf(" quiescing: %d\n", (int)sc->quiescing);
1989 	db_printf(" destroying: %d\n", (int)sc->destroying);
1990 	db_printf(" is_submitter_processing: %d\n",
1991 	    (int)sc->is_submitter_processing);
1992 	db_printf(" is_completion_pending: %d\n", (int)sc->is_completion_pending);
1993 	db_printf(" is_reset_pending: %d\n", (int)sc->is_reset_pending);
1994 	db_printf(" is_channel_running: %d\n", (int)sc->is_channel_running);
1995 	db_printf(" intrdelay_supported: %d\n", (int)sc->intrdelay_supported);
1996 	db_printf(" resetting: %d\n", (int)sc->resetting);
1997 
1998 	db_printf(" head: %u\n", sc->head);
1999 	db_printf(" tail: %u\n", sc->tail);
2000 	db_printf(" hw_head: %u\n", sc->hw_head);
2001 	db_printf(" ring_size_order: %u\n", sc->ring_size_order);
2002 	db_printf(" last_seen: 0x%lx\n", sc->last_seen);
2003 	db_printf(" ring: %p\n", sc->ring);
2004 	db_printf(" descriptors: %p\n", sc->hw_desc_ring);
2005 	db_printf(" descriptors (phys): 0x%jx\n",
2006 	    (uintmax_t)sc->hw_desc_bus_addr);
2007 
2008 	db_printf("  ring[%u] (tail):\n", sc->tail %
2009 	    (1 << sc->ring_size_order));
2010 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->tail)->id);
2011 	db_printf("   addr: 0x%lx\n",
2012 	    RING_PHYS_ADDR(sc, sc->tail));
2013 	db_printf("   next: 0x%lx\n",
2014 	     ioat_get_descriptor(sc, sc->tail)->generic.next);
2015 
2016 	db_printf("  ring[%u] (head - 1):\n", (sc->head - 1) %
2017 	    (1 << sc->ring_size_order));
2018 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head - 1)->id);
2019 	db_printf("   addr: 0x%lx\n",
2020 	    RING_PHYS_ADDR(sc, sc->head - 1));
2021 	db_printf("   next: 0x%lx\n",
2022 	     ioat_get_descriptor(sc, sc->head - 1)->generic.next);
2023 
2024 	db_printf("  ring[%u] (head):\n", (sc->head) %
2025 	    (1 << sc->ring_size_order));
2026 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head)->id);
2027 	db_printf("   addr: 0x%lx\n",
2028 	    RING_PHYS_ADDR(sc, sc->head));
2029 	db_printf("   next: 0x%lx\n",
2030 	     ioat_get_descriptor(sc, sc->head)->generic.next);
2031 
2032 	for (idx = 0; idx < (1 << sc->ring_size_order); idx++)
2033 		if ((*sc->comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK)
2034 		    == RING_PHYS_ADDR(sc, idx))
2035 			db_printf("  ring[%u] == hardware tail\n", idx);
2036 
2037 	db_printf(" cleanup_lock: ");
2038 	db_show_lock(&sc->cleanup_lock);
2039 
2040 	db_printf(" refcnt: %u\n", sc->refcnt);
2041 #ifdef INVARIANTS
2042 	CTASSERT(IOAT_NUM_REF_KINDS == 2);
2043 	db_printf(" refkinds: [ENG=%u, DESCR=%u]\n", sc->refkinds[0],
2044 	    sc->refkinds[1]);
2045 #endif
2046 	db_printf(" stats:\n");
2047 	db_printf("  interrupts: %lu\n", sc->stats.interrupts);
2048 	db_printf("  descriptors_processed: %lu\n", sc->stats.descriptors_processed);
2049 	db_printf("  descriptors_error: %lu\n", sc->stats.descriptors_error);
2050 	db_printf("  descriptors_submitted: %lu\n", sc->stats.descriptors_submitted);
2051 
2052 	db_printf("  channel_halts: %u\n", sc->stats.channel_halts);
2053 	db_printf("  last_halt_chanerr: %u\n", sc->stats.last_halt_chanerr);
2054 
2055 	if (db_pager_quit)
2056 		return;
2057 
2058 	db_printf(" hw status:\n");
2059 	db_printf("  status: 0x%lx\n", ioat_get_chansts(sc));
2060 	db_printf("  chanctrl: 0x%x\n",
2061 	    (unsigned)ioat_read_2(sc, IOAT_CHANCTRL_OFFSET));
2062 	db_printf("  chancmd: 0x%x\n",
2063 	    (unsigned)ioat_read_1(sc, IOAT_CHANCMD_OFFSET));
2064 	db_printf("  dmacount: 0x%x\n",
2065 	    (unsigned)ioat_read_2(sc, IOAT_DMACOUNT_OFFSET));
2066 	db_printf("  chainaddr: 0x%lx\n",
2067 	    ioat_read_double_4(sc, IOAT_CHAINADDR_OFFSET_LOW));
2068 	db_printf("  chancmp: 0x%lx\n",
2069 	    ioat_read_double_4(sc, IOAT_CHANCMP_OFFSET_LOW));
2070 	db_printf("  chanerr: %b\n",
2071 	    (int)ioat_read_4(sc, IOAT_CHANERR_OFFSET), IOAT_CHANERR_STR);
2072 	return;
2073 usage:
2074 	db_printf("usage: show ioat <0-%u>\n", ioat_channel_index);
2075 	return;
2076 }
2077 #endif /* DDB */
2078