xref: /freebsd/sys/dev/ioat/ioat.c (revision 0f7f3352c8bc463607912e2463d13e52d44a4cae)
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_SPACE_MAXADDR_40BIT, BUS_SPACE_MAXADDR,
490 	    NULL, NULL, ringsz, 1, ringsz, 0, NULL, NULL, &ioat->hw_desc_tag);
491 	if (error != 0)
492 		return (error);
493 
494 	error = bus_dmamem_alloc(ioat->hw_desc_tag, &hw_desc,
495 	    BUS_DMA_ZERO | BUS_DMA_WAITOK, &ioat->hw_desc_map);
496 	if (error != 0)
497 		return (error);
498 
499 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
500 	    ringsz, ioat_dmamap_cb, &ioat->hw_desc_bus_addr, BUS_DMA_WAITOK);
501 	if (error)
502 		return (error);
503 
504 	ioat->hw_desc_ring = hw_desc;
505 
506 	ioat->ring = malloc(num_descriptors * sizeof(*ring), M_IOAT,
507 	    M_ZERO | M_WAITOK);
508 
509 	ring = ioat->ring;
510 	for (i = 0; i < num_descriptors; i++) {
511 		memset(&ring[i].bus_dmadesc, 0, sizeof(ring[i].bus_dmadesc));
512 		ring[i].id = i;
513 	}
514 
515 	for (i = 0; i < num_descriptors; i++) {
516 		dma_hw_desc = &ioat->hw_desc_ring[i].dma;
517 		dma_hw_desc->next = RING_PHYS_ADDR(ioat, i + 1);
518 	}
519 
520 	ioat->head = ioat->hw_head = 0;
521 	ioat->tail = 0;
522 	ioat->last_seen = 0;
523 	*ioat->comp_update = 0;
524 	return (0);
525 }
526 
527 static int
528 ioat_map_pci_bar(struct ioat_softc *ioat)
529 {
530 
531 	ioat->pci_resource_id = PCIR_BAR(0);
532 	ioat->pci_resource = bus_alloc_resource_any(ioat->device,
533 	    SYS_RES_MEMORY, &ioat->pci_resource_id, RF_ACTIVE);
534 
535 	if (ioat->pci_resource == NULL) {
536 		ioat_log_message(0, "unable to allocate pci resource\n");
537 		return (ENODEV);
538 	}
539 
540 	ioat->pci_bus_tag = rman_get_bustag(ioat->pci_resource);
541 	ioat->pci_bus_handle = rman_get_bushandle(ioat->pci_resource);
542 	return (0);
543 }
544 
545 static void
546 ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
547 {
548 	struct ioat_softc *ioat = arg;
549 
550 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
551 	ioat->comp_update_bus_addr = seg[0].ds_addr;
552 }
553 
554 static void
555 ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
556 {
557 	bus_addr_t *baddr;
558 
559 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
560 	baddr = arg;
561 	*baddr = segs->ds_addr;
562 }
563 
564 /*
565  * Interrupt setup and handlers
566  */
567 static int
568 ioat_setup_intr(struct ioat_softc *ioat)
569 {
570 	uint32_t num_vectors;
571 	int error;
572 	boolean_t use_msix;
573 	boolean_t force_legacy_interrupts;
574 
575 	use_msix = FALSE;
576 	force_legacy_interrupts = FALSE;
577 
578 	if (!g_force_legacy_interrupts && pci_msix_count(ioat->device) >= 1) {
579 		num_vectors = 1;
580 		pci_alloc_msix(ioat->device, &num_vectors);
581 		if (num_vectors == 1)
582 			use_msix = TRUE;
583 	}
584 
585 	if (use_msix) {
586 		ioat->rid = 1;
587 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
588 		    &ioat->rid, RF_ACTIVE);
589 	} else {
590 		ioat->rid = 0;
591 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
592 		    &ioat->rid, RF_SHAREABLE | RF_ACTIVE);
593 	}
594 	if (ioat->res == NULL) {
595 		ioat_log_message(0, "bus_alloc_resource failed\n");
596 		return (ENOMEM);
597 	}
598 
599 	ioat->tag = NULL;
600 	error = bus_setup_intr(ioat->device, ioat->res, INTR_MPSAFE |
601 	    INTR_TYPE_MISC, NULL, ioat_interrupt_handler, ioat, &ioat->tag);
602 	if (error != 0) {
603 		ioat_log_message(0, "bus_setup_intr failed\n");
604 		return (error);
605 	}
606 
607 	ioat_write_intrctrl(ioat, IOAT_INTRCTRL_MASTER_INT_EN);
608 	return (0);
609 }
610 
611 static boolean_t
612 ioat_model_resets_msix(struct ioat_softc *ioat)
613 {
614 	u_int32_t pciid;
615 
616 	pciid = pci_get_devid(ioat->device);
617 	switch (pciid) {
618 		/* BWD: */
619 	case 0x0c508086:
620 	case 0x0c518086:
621 	case 0x0c528086:
622 	case 0x0c538086:
623 		/* BDXDE: */
624 	case 0x6f508086:
625 	case 0x6f518086:
626 	case 0x6f528086:
627 	case 0x6f538086:
628 		return (TRUE);
629 	}
630 
631 	return (FALSE);
632 }
633 
634 static void
635 ioat_interrupt_handler(void *arg)
636 {
637 	struct ioat_softc *ioat = arg;
638 
639 	ioat->stats.interrupts++;
640 	ioat_process_events(ioat);
641 }
642 
643 static int
644 chanerr_to_errno(uint32_t chanerr)
645 {
646 
647 	if (chanerr == 0)
648 		return (0);
649 	if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
650 		return (EFAULT);
651 	if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
652 		return (EIO);
653 	/* This one is probably our fault: */
654 	if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
655 		return (EIO);
656 	return (EIO);
657 }
658 
659 static void
660 ioat_process_events(struct ioat_softc *ioat)
661 {
662 	struct ioat_descriptor *desc;
663 	struct bus_dmadesc *dmadesc;
664 	uint64_t comp_update, status;
665 	uint32_t completed, chanerr;
666 	boolean_t pending;
667 	int error;
668 
669 	mtx_lock(&ioat->cleanup_lock);
670 
671 	/*
672 	 * Don't run while the hardware is being reset.  Reset is responsible
673 	 * for blocking new work and draining & completing existing work, so
674 	 * there is nothing to do until new work is queued after reset anyway.
675 	 */
676 	if (ioat->resetting_cleanup) {
677 		mtx_unlock(&ioat->cleanup_lock);
678 		return;
679 	}
680 
681 	completed = 0;
682 	comp_update = *ioat->comp_update;
683 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
684 
685 	if (status < ioat->hw_desc_bus_addr ||
686 	    status >= ioat->hw_desc_bus_addr + (1 << ioat->ring_size_order) *
687 	    sizeof(struct ioat_generic_hw_descriptor))
688 		panic("Bogus completion address %jx (channel %u)",
689 		    (uintmax_t)status, ioat->chan_idx);
690 
691 	if (status == ioat->last_seen) {
692 		/*
693 		 * If we landed in process_events and nothing has been
694 		 * completed, check for a timeout due to channel halt.
695 		 */
696 		goto out;
697 	}
698 	CTR4(KTR_IOAT, "%s channel=%u hw_status=0x%lx last_seen=0x%lx",
699 	    __func__, ioat->chan_idx, comp_update, ioat->last_seen);
700 
701 	while (RING_PHYS_ADDR(ioat, ioat->tail - 1) != status) {
702 		desc = ioat_get_ring_entry(ioat, ioat->tail);
703 		dmadesc = &desc->bus_dmadesc;
704 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) ok  cb %p(%p)",
705 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
706 		    dmadesc->callback_arg);
707 
708 		if (dmadesc->callback_fn != NULL)
709 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
710 
711 		completed++;
712 		ioat->tail++;
713 	}
714 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
715 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
716 
717 	if (completed != 0) {
718 		ioat->last_seen = RING_PHYS_ADDR(ioat, ioat->tail - 1);
719 		ioat->stats.descriptors_processed += completed;
720 	}
721 
722 out:
723 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
724 
725 	/* Perform a racy check first; only take the locks if it passes. */
726 	pending = (ioat_get_active(ioat) != 0);
727 	if (!pending && ioat->is_completion_pending) {
728 		mtx_unlock(&ioat->cleanup_lock);
729 		mtx_lock(&ioat->submit_lock);
730 		mtx_lock(&ioat->cleanup_lock);
731 
732 		pending = (ioat_get_active(ioat) != 0);
733 		if (!pending && ioat->is_completion_pending) {
734 			ioat->is_completion_pending = FALSE;
735 			callout_stop(&ioat->poll_timer);
736 		}
737 		mtx_unlock(&ioat->submit_lock);
738 	}
739 	mtx_unlock(&ioat->cleanup_lock);
740 
741 	if (pending)
742 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
743 		    ioat);
744 
745 	if (completed != 0) {
746 		ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
747 		wakeup(&ioat->tail);
748 	}
749 
750 	/*
751 	 * The device doesn't seem to reliably push suspend/halt statuses to
752 	 * the channel completion memory address, so poll the device register
753 	 * here.
754 	 */
755 	comp_update = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
756 	if (!is_ioat_halted(comp_update) && !is_ioat_suspended(comp_update))
757 		return;
758 
759 	ioat->stats.channel_halts++;
760 
761 	/*
762 	 * Fatal programming error on this DMA channel.  Flush any outstanding
763 	 * work with error status and restart the engine.
764 	 */
765 	mtx_lock(&ioat->submit_lock);
766 	mtx_lock(&ioat->cleanup_lock);
767 	ioat->quiescing = TRUE;
768 	/*
769 	 * This is safe to do here because we have both locks and the submit
770 	 * queue is quiesced.  We know that we will drain all outstanding
771 	 * events, so ioat_reset_hw can't deadlock.  It is necessary to
772 	 * protect other ioat_process_event threads from racing ioat_reset_hw,
773 	 * reading an indeterminate hw state, and attempting to continue
774 	 * issuing completions.
775 	 */
776 	ioat->resetting_cleanup = TRUE;
777 
778 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
779 	if (1 <= g_ioat_debug_level)
780 		ioat_halted_debug(ioat, chanerr);
781 	ioat->stats.last_halt_chanerr = chanerr;
782 
783 	while (ioat_get_active(ioat) > 0) {
784 		desc = ioat_get_ring_entry(ioat, ioat->tail);
785 		dmadesc = &desc->bus_dmadesc;
786 		CTR5(KTR_IOAT, "channel=%u completing desc idx %u (%p) err cb %p(%p)",
787 		    ioat->chan_idx, ioat->tail, dmadesc, dmadesc->callback_fn,
788 		    dmadesc->callback_arg);
789 
790 		if (dmadesc->callback_fn != NULL)
791 			dmadesc->callback_fn(dmadesc->callback_arg,
792 			    chanerr_to_errno(chanerr));
793 
794 		ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
795 		ioat->tail++;
796 		ioat->stats.descriptors_processed++;
797 		ioat->stats.descriptors_error++;
798 	}
799 	CTR5(KTR_IOAT, "%s channel=%u head=%u tail=%u active=%u", __func__,
800 	    ioat->chan_idx, ioat->head, ioat->tail, ioat_get_active(ioat));
801 
802 	if (ioat->is_completion_pending) {
803 		ioat->is_completion_pending = FALSE;
804 		callout_stop(&ioat->poll_timer);
805 	}
806 
807 	/* Clear error status */
808 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
809 
810 	mtx_unlock(&ioat->cleanup_lock);
811 	mtx_unlock(&ioat->submit_lock);
812 
813 	ioat_log_message(0, "Resetting channel to recover from error\n");
814 	error = taskqueue_enqueue(taskqueue_thread, &ioat->reset_task);
815 	KASSERT(error == 0,
816 	    ("%s: taskqueue_enqueue failed: %d", __func__, error));
817 }
818 
819 static void
820 ioat_reset_hw_task(void *ctx, int pending __unused)
821 {
822 	struct ioat_softc *ioat;
823 	int error;
824 
825 	ioat = ctx;
826 	ioat_log_message(1, "%s: Resetting channel\n", __func__);
827 
828 	error = ioat_reset_hw(ioat);
829 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
830 	(void)error;
831 }
832 
833 /*
834  * User API functions
835  */
836 unsigned
837 ioat_get_nchannels(void)
838 {
839 
840 	return (ioat_channel_index);
841 }
842 
843 bus_dmaengine_t
844 ioat_get_dmaengine(uint32_t index, int flags)
845 {
846 	struct ioat_softc *ioat;
847 
848 	KASSERT((flags & ~(M_NOWAIT | M_WAITOK)) == 0,
849 	    ("invalid flags: 0x%08x", flags));
850 	KASSERT((flags & (M_NOWAIT | M_WAITOK)) != (M_NOWAIT | M_WAITOK),
851 	    ("invalid wait | nowait"));
852 
853 	if (index >= ioat_channel_index)
854 		return (NULL);
855 
856 	ioat = ioat_channel[index];
857 	if (ioat == NULL || ioat->destroying)
858 		return (NULL);
859 
860 	if (ioat->quiescing) {
861 		if ((flags & M_NOWAIT) != 0)
862 			return (NULL);
863 
864 		mtx_lock(IOAT_REFLK);
865 		while (ioat->quiescing && !ioat->destroying)
866 			msleep(&ioat->quiescing, IOAT_REFLK, 0, "getdma", 0);
867 		mtx_unlock(IOAT_REFLK);
868 
869 		if (ioat->destroying)
870 			return (NULL);
871 	}
872 
873 	/*
874 	 * There's a race here between the quiescing check and HW reset or
875 	 * module destroy.
876 	 */
877 	return (&ioat_get(ioat, IOAT_DMAENGINE_REF)->dmaengine);
878 }
879 
880 void
881 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
882 {
883 	struct ioat_softc *ioat;
884 
885 	ioat = to_ioat_softc(dmaengine);
886 	ioat_put(ioat, IOAT_DMAENGINE_REF);
887 }
888 
889 int
890 ioat_get_hwversion(bus_dmaengine_t dmaengine)
891 {
892 	struct ioat_softc *ioat;
893 
894 	ioat = to_ioat_softc(dmaengine);
895 	return (ioat->version);
896 }
897 
898 size_t
899 ioat_get_max_io_size(bus_dmaengine_t dmaengine)
900 {
901 	struct ioat_softc *ioat;
902 
903 	ioat = to_ioat_softc(dmaengine);
904 	return (ioat->max_xfer_size);
905 }
906 
907 uint32_t
908 ioat_get_capabilities(bus_dmaengine_t dmaengine)
909 {
910 	struct ioat_softc *ioat;
911 
912 	ioat = to_ioat_softc(dmaengine);
913 	return (ioat->capabilities);
914 }
915 
916 int
917 ioat_set_interrupt_coalesce(bus_dmaengine_t dmaengine, uint16_t delay)
918 {
919 	struct ioat_softc *ioat;
920 
921 	ioat = to_ioat_softc(dmaengine);
922 	if (!ioat->intrdelay_supported)
923 		return (ENODEV);
924 	if (delay > ioat->intrdelay_max)
925 		return (ERANGE);
926 
927 	ioat_write_2(ioat, IOAT_INTRDELAY_OFFSET, delay);
928 	ioat->cached_intrdelay =
929 	    ioat_read_2(ioat, IOAT_INTRDELAY_OFFSET) & IOAT_INTRDELAY_US_MASK;
930 	return (0);
931 }
932 
933 uint16_t
934 ioat_get_max_coalesce_period(bus_dmaengine_t dmaengine)
935 {
936 	struct ioat_softc *ioat;
937 
938 	ioat = to_ioat_softc(dmaengine);
939 	return (ioat->intrdelay_max);
940 }
941 
942 void
943 ioat_acquire(bus_dmaengine_t dmaengine)
944 {
945 	struct ioat_softc *ioat;
946 
947 	ioat = to_ioat_softc(dmaengine);
948 	mtx_lock(&ioat->submit_lock);
949 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
950 }
951 
952 int
953 ioat_acquire_reserve(bus_dmaengine_t dmaengine, unsigned n, int mflags)
954 {
955 	struct ioat_softc *ioat;
956 	int error;
957 
958 	ioat = to_ioat_softc(dmaengine);
959 	ioat_acquire(dmaengine);
960 
961 	error = ioat_reserve_space(ioat, n, mflags);
962 	if (error != 0)
963 		ioat_release(dmaengine);
964 	return (error);
965 }
966 
967 void
968 ioat_release(bus_dmaengine_t dmaengine)
969 {
970 	struct ioat_softc *ioat;
971 
972 	ioat = to_ioat_softc(dmaengine);
973 	CTR4(KTR_IOAT, "%s channel=%u dispatch1 hw_head=%u head=%u", __func__,
974 	    ioat->chan_idx, ioat->hw_head & UINT16_MAX, ioat->head);
975 	KFAIL_POINT_CODE(DEBUG_FP, ioat_release, /* do nothing */);
976 	CTR4(KTR_IOAT, "%s channel=%u dispatch2 hw_head=%u head=%u", __func__,
977 	    ioat->chan_idx, ioat->hw_head & UINT16_MAX, ioat->head);
978 
979 	ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET, (uint16_t)ioat->hw_head);
980 
981 	if (!ioat->is_completion_pending) {
982 		ioat->is_completion_pending = TRUE;
983 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
984 		    ioat);
985 	}
986 	mtx_unlock(&ioat->submit_lock);
987 }
988 
989 static struct ioat_descriptor *
990 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
991     uint32_t size, uint64_t src, uint64_t dst,
992     bus_dmaengine_callback_t callback_fn, void *callback_arg,
993     uint32_t flags)
994 {
995 	struct ioat_generic_hw_descriptor *hw_desc;
996 	struct ioat_descriptor *desc;
997 	int mflags;
998 
999 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1000 
1001 	KASSERT((flags & ~_DMA_GENERIC_FLAGS) == 0,
1002 	    ("Unrecognized flag(s): %#x", flags & ~_DMA_GENERIC_FLAGS));
1003 	if ((flags & DMA_NO_WAIT) != 0)
1004 		mflags = M_NOWAIT;
1005 	else
1006 		mflags = M_WAITOK;
1007 
1008 	if (size > ioat->max_xfer_size) {
1009 		ioat_log_message(0, "%s: max_xfer_size = %d, requested = %u\n",
1010 		    __func__, ioat->max_xfer_size, (unsigned)size);
1011 		return (NULL);
1012 	}
1013 
1014 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
1015 		return (NULL);
1016 
1017 	desc = ioat_get_ring_entry(ioat, ioat->head);
1018 	hw_desc = &ioat_get_descriptor(ioat, ioat->head)->generic;
1019 
1020 	hw_desc->u.control_raw = 0;
1021 	hw_desc->u.control_generic.op = op;
1022 	hw_desc->u.control_generic.completion_update = 1;
1023 
1024 	if ((flags & DMA_INT_EN) != 0)
1025 		hw_desc->u.control_generic.int_enable = 1;
1026 	if ((flags & DMA_FENCE) != 0)
1027 		hw_desc->u.control_generic.fence = 1;
1028 
1029 	hw_desc->size = size;
1030 	hw_desc->src_addr = src;
1031 	hw_desc->dest_addr = dst;
1032 
1033 	desc->bus_dmadesc.callback_fn = callback_fn;
1034 	desc->bus_dmadesc.callback_arg = callback_arg;
1035 	return (desc);
1036 }
1037 
1038 struct bus_dmadesc *
1039 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
1040     void *callback_arg, uint32_t flags)
1041 {
1042 	struct ioat_dma_hw_descriptor *hw_desc;
1043 	struct ioat_descriptor *desc;
1044 	struct ioat_softc *ioat;
1045 
1046 	ioat = to_ioat_softc(dmaengine);
1047 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1048 
1049 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
1050 	    callback_arg, flags);
1051 	if (desc == NULL)
1052 		return (NULL);
1053 
1054 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1055 	hw_desc->u.control.null = 1;
1056 	ioat_submit_single(ioat);
1057 	return (&desc->bus_dmadesc);
1058 }
1059 
1060 struct bus_dmadesc *
1061 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
1062     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
1063     void *callback_arg, uint32_t flags)
1064 {
1065 	struct ioat_dma_hw_descriptor *hw_desc;
1066 	struct ioat_descriptor *desc;
1067 	struct ioat_softc *ioat;
1068 
1069 	ioat = to_ioat_softc(dmaengine);
1070 
1071 	if (((src | dst) & (0xffffull << 48)) != 0) {
1072 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1073 		    __func__);
1074 		return (NULL);
1075 	}
1076 
1077 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
1078 	    callback_arg, flags);
1079 	if (desc == NULL)
1080 		return (NULL);
1081 
1082 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1083 	if (g_ioat_debug_level >= 3)
1084 		dump_descriptor(hw_desc);
1085 
1086 	ioat_submit_single(ioat);
1087 	CTR6(KTR_IOAT, "%s channel=%u desc=%p dest=%lx src=%lx len=%lx",
1088 	    __func__, ioat->chan_idx, &desc->bus_dmadesc, dst, src, len);
1089 	return (&desc->bus_dmadesc);
1090 }
1091 
1092 struct bus_dmadesc *
1093 ioat_copy_8k_aligned(bus_dmaengine_t dmaengine, bus_addr_t dst1,
1094     bus_addr_t dst2, bus_addr_t src1, bus_addr_t src2,
1095     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1096 {
1097 	struct ioat_dma_hw_descriptor *hw_desc;
1098 	struct ioat_descriptor *desc;
1099 	struct ioat_softc *ioat;
1100 
1101 	ioat = to_ioat_softc(dmaengine);
1102 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1103 
1104 	if (((src1 | src2 | dst1 | dst2) & (0xffffull << 48)) != 0) {
1105 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
1106 		    __func__);
1107 		return (NULL);
1108 	}
1109 	if (((src1 | src2 | dst1 | dst2) & PAGE_MASK) != 0) {
1110 		ioat_log_message(0, "%s: Addresses must be page-aligned\n",
1111 		    __func__);
1112 		return (NULL);
1113 	}
1114 
1115 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 2 * PAGE_SIZE, src1, dst1,
1116 	    callback_fn, callback_arg, flags);
1117 	if (desc == NULL)
1118 		return (NULL);
1119 
1120 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->dma;
1121 	if (src2 != src1 + PAGE_SIZE) {
1122 		hw_desc->u.control.src_page_break = 1;
1123 		hw_desc->next_src_addr = src2;
1124 	}
1125 	if (dst2 != dst1 + PAGE_SIZE) {
1126 		hw_desc->u.control.dest_page_break = 1;
1127 		hw_desc->next_dest_addr = dst2;
1128 	}
1129 
1130 	if (g_ioat_debug_level >= 3)
1131 		dump_descriptor(hw_desc);
1132 
1133 	ioat_submit_single(ioat);
1134 	return (&desc->bus_dmadesc);
1135 }
1136 
1137 struct bus_dmadesc *
1138 ioat_copy_crc(bus_dmaengine_t dmaengine, bus_addr_t dst, bus_addr_t src,
1139     bus_size_t len, uint32_t *initialseed, bus_addr_t crcptr,
1140     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1141 {
1142 	struct ioat_crc32_hw_descriptor *hw_desc;
1143 	struct ioat_descriptor *desc;
1144 	struct ioat_softc *ioat;
1145 	uint32_t teststore;
1146 	uint8_t op;
1147 
1148 	ioat = to_ioat_softc(dmaengine);
1149 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1150 
1151 	if ((ioat->capabilities & IOAT_DMACAP_MOVECRC) == 0) {
1152 		ioat_log_message(0, "%s: Device lacks MOVECRC capability\n",
1153 		    __func__);
1154 		return (NULL);
1155 	}
1156 	if (((src | dst) & (0xffffffull << 40)) != 0) {
1157 		ioat_log_message(0, "%s: High 24 bits of src/dst invalid\n",
1158 		    __func__);
1159 		return (NULL);
1160 	}
1161 	teststore = (flags & _DMA_CRC_TESTSTORE);
1162 	if (teststore == _DMA_CRC_TESTSTORE) {
1163 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1164 		return (NULL);
1165 	}
1166 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1167 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1168 		    __func__);
1169 		return (NULL);
1170 	}
1171 
1172 	switch (teststore) {
1173 	case DMA_CRC_STORE:
1174 		op = IOAT_OP_MOVECRC_STORE;
1175 		break;
1176 	case DMA_CRC_TEST:
1177 		op = IOAT_OP_MOVECRC_TEST;
1178 		break;
1179 	default:
1180 		KASSERT(teststore == 0, ("bogus"));
1181 		op = IOAT_OP_MOVECRC;
1182 		break;
1183 	}
1184 
1185 	if ((flags & DMA_CRC_INLINE) == 0 &&
1186 	    (crcptr & (0xffffffull << 40)) != 0) {
1187 		ioat_log_message(0,
1188 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1189 		return (NULL);
1190 	}
1191 
1192 	desc = ioat_op_generic(ioat, op, len, src, dst, callback_fn,
1193 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1194 	if (desc == NULL)
1195 		return (NULL);
1196 
1197 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1198 
1199 	if ((flags & DMA_CRC_INLINE) == 0)
1200 		hw_desc->crc_address = crcptr;
1201 	else
1202 		hw_desc->u.control.crc_location = 1;
1203 
1204 	if (initialseed != NULL) {
1205 		hw_desc->u.control.use_seed = 1;
1206 		hw_desc->seed = *initialseed;
1207 	}
1208 
1209 	if (g_ioat_debug_level >= 3)
1210 		dump_descriptor(hw_desc);
1211 
1212 	ioat_submit_single(ioat);
1213 	return (&desc->bus_dmadesc);
1214 }
1215 
1216 struct bus_dmadesc *
1217 ioat_crc(bus_dmaengine_t dmaengine, bus_addr_t src, bus_size_t len,
1218     uint32_t *initialseed, bus_addr_t crcptr,
1219     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags)
1220 {
1221 	struct ioat_crc32_hw_descriptor *hw_desc;
1222 	struct ioat_descriptor *desc;
1223 	struct ioat_softc *ioat;
1224 	uint32_t teststore;
1225 	uint8_t op;
1226 
1227 	ioat = to_ioat_softc(dmaengine);
1228 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1229 
1230 	if ((ioat->capabilities & IOAT_DMACAP_CRC) == 0) {
1231 		ioat_log_message(0, "%s: Device lacks CRC capability\n",
1232 		    __func__);
1233 		return (NULL);
1234 	}
1235 	if ((src & (0xffffffull << 40)) != 0) {
1236 		ioat_log_message(0, "%s: High 24 bits of src invalid\n",
1237 		    __func__);
1238 		return (NULL);
1239 	}
1240 	teststore = (flags & _DMA_CRC_TESTSTORE);
1241 	if (teststore == _DMA_CRC_TESTSTORE) {
1242 		ioat_log_message(0, "%s: TEST and STORE invalid\n", __func__);
1243 		return (NULL);
1244 	}
1245 	if (teststore == 0 && (flags & DMA_CRC_INLINE) != 0) {
1246 		ioat_log_message(0, "%s: INLINE invalid without TEST or STORE\n",
1247 		    __func__);
1248 		return (NULL);
1249 	}
1250 
1251 	switch (teststore) {
1252 	case DMA_CRC_STORE:
1253 		op = IOAT_OP_CRC_STORE;
1254 		break;
1255 	case DMA_CRC_TEST:
1256 		op = IOAT_OP_CRC_TEST;
1257 		break;
1258 	default:
1259 		KASSERT(teststore == 0, ("bogus"));
1260 		op = IOAT_OP_CRC;
1261 		break;
1262 	}
1263 
1264 	if ((flags & DMA_CRC_INLINE) == 0 &&
1265 	    (crcptr & (0xffffffull << 40)) != 0) {
1266 		ioat_log_message(0,
1267 		    "%s: High 24 bits of crcptr invalid\n", __func__);
1268 		return (NULL);
1269 	}
1270 
1271 	desc = ioat_op_generic(ioat, op, len, src, 0, callback_fn,
1272 	    callback_arg, flags & ~_DMA_CRC_FLAGS);
1273 	if (desc == NULL)
1274 		return (NULL);
1275 
1276 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->crc32;
1277 
1278 	if ((flags & DMA_CRC_INLINE) == 0)
1279 		hw_desc->crc_address = crcptr;
1280 	else
1281 		hw_desc->u.control.crc_location = 1;
1282 
1283 	if (initialseed != NULL) {
1284 		hw_desc->u.control.use_seed = 1;
1285 		hw_desc->seed = *initialseed;
1286 	}
1287 
1288 	if (g_ioat_debug_level >= 3)
1289 		dump_descriptor(hw_desc);
1290 
1291 	ioat_submit_single(ioat);
1292 	return (&desc->bus_dmadesc);
1293 }
1294 
1295 struct bus_dmadesc *
1296 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
1297     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
1298     uint32_t flags)
1299 {
1300 	struct ioat_fill_hw_descriptor *hw_desc;
1301 	struct ioat_descriptor *desc;
1302 	struct ioat_softc *ioat;
1303 
1304 	ioat = to_ioat_softc(dmaengine);
1305 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1306 
1307 	if ((ioat->capabilities & IOAT_DMACAP_BFILL) == 0) {
1308 		ioat_log_message(0, "%s: Device lacks BFILL capability\n",
1309 		    __func__);
1310 		return (NULL);
1311 	}
1312 
1313 	if ((dst & (0xffffull << 48)) != 0) {
1314 		ioat_log_message(0, "%s: High 16 bits of dst invalid\n",
1315 		    __func__);
1316 		return (NULL);
1317 	}
1318 
1319 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, fillpattern, dst,
1320 	    callback_fn, callback_arg, flags);
1321 	if (desc == NULL)
1322 		return (NULL);
1323 
1324 	hw_desc = &ioat_get_descriptor(ioat, desc->id)->fill;
1325 	if (g_ioat_debug_level >= 3)
1326 		dump_descriptor(hw_desc);
1327 
1328 	ioat_submit_single(ioat);
1329 	return (&desc->bus_dmadesc);
1330 }
1331 
1332 /*
1333  * Ring Management
1334  */
1335 static inline uint32_t
1336 ioat_get_active(struct ioat_softc *ioat)
1337 {
1338 
1339 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
1340 }
1341 
1342 static inline uint32_t
1343 ioat_get_ring_space(struct ioat_softc *ioat)
1344 {
1345 
1346 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
1347 }
1348 
1349 /*
1350  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
1351  * for 'num_descs'.
1352  *
1353  * If mflags contains M_WAITOK, blocks until enough space is available.
1354  *
1355  * Returns zero on success, or an errno on error.  If num_descs is beyond the
1356  * maximum ring size, returns EINVAl; if allocation would block and mflags
1357  * contains M_NOWAIT, returns EAGAIN.
1358  *
1359  * Must be called with the submit_lock held; returns with the lock held.  The
1360  * lock may be dropped to allocate the ring.
1361  *
1362  * (The submit_lock is needed to add any entries to the ring, so callers are
1363  * assured enough room is available.)
1364  */
1365 static int
1366 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
1367 {
1368 	boolean_t dug;
1369 	int error;
1370 
1371 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1372 	error = 0;
1373 	dug = FALSE;
1374 
1375 	if (num_descs < 1 || num_descs >= (1 << ioat->ring_size_order)) {
1376 		error = EINVAL;
1377 		goto out;
1378 	}
1379 
1380 	for (;;) {
1381 		if (ioat->quiescing) {
1382 			error = ENXIO;
1383 			goto out;
1384 		}
1385 
1386 		if (ioat_get_ring_space(ioat) >= num_descs)
1387 			goto out;
1388 
1389 		CTR3(KTR_IOAT, "%s channel=%u starved (%u)", __func__,
1390 		    ioat->chan_idx, num_descs);
1391 
1392 		if (!dug && !ioat->is_submitter_processing) {
1393 			ioat->is_submitter_processing = TRUE;
1394 			mtx_unlock(&ioat->submit_lock);
1395 
1396 			CTR2(KTR_IOAT, "%s channel=%u attempting to process events",
1397 			    __func__, ioat->chan_idx);
1398 			ioat_process_events(ioat);
1399 
1400 			mtx_lock(&ioat->submit_lock);
1401 			dug = TRUE;
1402 			KASSERT(ioat->is_submitter_processing == TRUE,
1403 			    ("is_submitter_processing"));
1404 			ioat->is_submitter_processing = FALSE;
1405 			wakeup(&ioat->tail);
1406 			continue;
1407 		}
1408 
1409 		if ((mflags & M_WAITOK) == 0) {
1410 			error = EAGAIN;
1411 			break;
1412 		}
1413 		CTR2(KTR_IOAT, "%s channel=%u blocking on completions",
1414 		    __func__, ioat->chan_idx);
1415 		msleep(&ioat->tail, &ioat->submit_lock, 0,
1416 		    "ioat_full", 0);
1417 		continue;
1418 	}
1419 
1420 out:
1421 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1422 	KASSERT(!ioat->quiescing || error == ENXIO,
1423 	    ("reserved during quiesce"));
1424 	return (error);
1425 }
1426 
1427 static void
1428 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1429     struct ioat_descriptor *ring)
1430 {
1431 
1432 	free(ring, M_IOAT);
1433 }
1434 
1435 static struct ioat_descriptor *
1436 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1437 {
1438 
1439 	return (&ioat->ring[index % (1 << ioat->ring_size_order)]);
1440 }
1441 
1442 static union ioat_hw_descriptor *
1443 ioat_get_descriptor(struct ioat_softc *ioat, uint32_t index)
1444 {
1445 
1446 	return (&ioat->hw_desc_ring[index % (1 << ioat->ring_size_order)]);
1447 }
1448 
1449 static void
1450 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1451 {
1452 	union ioat_hw_descriptor *desc;
1453 
1454 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1455 	    IOAT_CHANERR_STR);
1456 	if (chanerr == 0)
1457 		return;
1458 
1459 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1460 
1461 	desc = ioat_get_descriptor(ioat, ioat->tail + 0);
1462 	dump_descriptor(desc);
1463 
1464 	desc = ioat_get_descriptor(ioat, ioat->tail + 1);
1465 	dump_descriptor(desc);
1466 }
1467 
1468 static void
1469 ioat_poll_timer_callback(void *arg)
1470 {
1471 	struct ioat_softc *ioat;
1472 
1473 	ioat = arg;
1474 	ioat_log_message(3, "%s\n", __func__);
1475 
1476 	ioat_process_events(ioat);
1477 }
1478 
1479 /*
1480  * Support Functions
1481  */
1482 static void
1483 ioat_submit_single(struct ioat_softc *ioat)
1484 {
1485 
1486 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1487 
1488 	ioat_get(ioat, IOAT_ACTIVE_DESCR_REF);
1489 	atomic_add_rel_int(&ioat->head, 1);
1490 	atomic_add_rel_int(&ioat->hw_head, 1);
1491 	CTR5(KTR_IOAT, "%s channel=%u head=%u hw_head=%u tail=%u", __func__,
1492 	    ioat->chan_idx, ioat->head, ioat->hw_head & UINT16_MAX,
1493 	    ioat->tail);
1494 
1495 	ioat->stats.descriptors_submitted++;
1496 }
1497 
1498 static int
1499 ioat_reset_hw(struct ioat_softc *ioat)
1500 {
1501 	uint64_t status;
1502 	uint32_t chanerr;
1503 	unsigned timeout;
1504 	int error;
1505 
1506 	CTR2(KTR_IOAT, "%s channel=%u", __func__, ioat->chan_idx);
1507 
1508 	mtx_lock(IOAT_REFLK);
1509 	while (ioat->resetting && !ioat->destroying)
1510 		msleep(&ioat->resetting, IOAT_REFLK, 0, "IRH_drain", 0);
1511 	if (ioat->destroying) {
1512 		mtx_unlock(IOAT_REFLK);
1513 		return (ENXIO);
1514 	}
1515 	ioat->resetting = TRUE;
1516 
1517 	ioat->quiescing = TRUE;
1518 	ioat_drain_locked(ioat);
1519 	mtx_unlock(IOAT_REFLK);
1520 
1521 	/*
1522 	 * Suspend ioat_process_events while the hardware and softc are in an
1523 	 * indeterminate state.
1524 	 */
1525 	mtx_lock(&ioat->cleanup_lock);
1526 	ioat->resetting_cleanup = TRUE;
1527 	mtx_unlock(&ioat->cleanup_lock);
1528 
1529 	CTR2(KTR_IOAT, "%s channel=%u quiesced and drained", __func__,
1530 	    ioat->chan_idx);
1531 
1532 	status = ioat_get_chansts(ioat);
1533 	if (is_ioat_active(status) || is_ioat_idle(status))
1534 		ioat_suspend(ioat);
1535 
1536 	/* Wait at most 20 ms */
1537 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1538 	    timeout < 20; timeout++) {
1539 		DELAY(1000);
1540 		status = ioat_get_chansts(ioat);
1541 	}
1542 	if (timeout == 20) {
1543 		error = ETIMEDOUT;
1544 		goto out;
1545 	}
1546 
1547 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1548 
1549 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1550 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1551 
1552 	CTR2(KTR_IOAT, "%s channel=%u hardware suspended", __func__,
1553 	    ioat->chan_idx);
1554 
1555 	/*
1556 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1557 	 *  that can cause stability issues for IOAT v3.
1558 	 */
1559 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1560 	    4);
1561 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1562 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1563 
1564 	/*
1565 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1566 	 * Save/restore their contents manually.
1567 	 */
1568 	if (ioat_model_resets_msix(ioat)) {
1569 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1570 		pci_save_state(ioat->device);
1571 	}
1572 
1573 	ioat_reset(ioat);
1574 	CTR2(KTR_IOAT, "%s channel=%u hardware reset", __func__,
1575 	    ioat->chan_idx);
1576 
1577 	/* Wait at most 20 ms */
1578 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1579 		DELAY(1000);
1580 	if (timeout == 20) {
1581 		error = ETIMEDOUT;
1582 		goto out;
1583 	}
1584 
1585 	if (ioat_model_resets_msix(ioat)) {
1586 		ioat_log_message(1, "device resets registers; restored\n");
1587 		pci_restore_state(ioat->device);
1588 	}
1589 
1590 	/* Reset attempts to return the hardware to "halted." */
1591 	status = ioat_get_chansts(ioat);
1592 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1593 		/* So this really shouldn't happen... */
1594 		ioat_log_message(0, "Device is active after a reset?\n");
1595 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1596 		error = 0;
1597 		goto out;
1598 	}
1599 
1600 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1601 	if (chanerr != 0) {
1602 		mtx_lock(&ioat->cleanup_lock);
1603 		ioat_halted_debug(ioat, chanerr);
1604 		mtx_unlock(&ioat->cleanup_lock);
1605 		error = EIO;
1606 		goto out;
1607 	}
1608 
1609 	/*
1610 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1611 	 * device back to active.
1612 	 *
1613 	 * The internal ring counter resets to zero, so we have to start over
1614 	 * at zero as well.
1615 	 */
1616 	ioat->tail = ioat->head = ioat->hw_head = 0;
1617 	ioat->last_seen = 0;
1618 	*ioat->comp_update = 0;
1619 	KASSERT(!ioat->is_completion_pending, ("bogus completion_pending"));
1620 
1621 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1622 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1623 	ioat_write_chainaddr(ioat, RING_PHYS_ADDR(ioat, 0));
1624 	error = 0;
1625 	CTR2(KTR_IOAT, "%s channel=%u configured channel", __func__,
1626 	    ioat->chan_idx);
1627 
1628 out:
1629 	/* Enqueues a null operation and ensures it completes. */
1630 	if (error == 0) {
1631 		error = ioat_start_channel(ioat);
1632 		CTR2(KTR_IOAT, "%s channel=%u started channel", __func__,
1633 		    ioat->chan_idx);
1634 	}
1635 
1636 	/*
1637 	 * Resume completions now that ring state is consistent.
1638 	 */
1639 	mtx_lock(&ioat->cleanup_lock);
1640 	ioat->resetting_cleanup = FALSE;
1641 	mtx_unlock(&ioat->cleanup_lock);
1642 
1643 	/* Unblock submission of new work */
1644 	mtx_lock(IOAT_REFLK);
1645 	ioat->quiescing = FALSE;
1646 	wakeup(&ioat->quiescing);
1647 
1648 	ioat->resetting = FALSE;
1649 	wakeup(&ioat->resetting);
1650 
1651 	if (ioat->is_completion_pending)
1652 		callout_reset(&ioat->poll_timer, 1, ioat_poll_timer_callback,
1653 		    ioat);
1654 	CTR2(KTR_IOAT, "%s channel=%u reset done", __func__, ioat->chan_idx);
1655 	mtx_unlock(IOAT_REFLK);
1656 
1657 	return (error);
1658 }
1659 
1660 static int
1661 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1662 {
1663 	struct ioat_softc *ioat;
1664 	struct sbuf sb;
1665 	uint64_t status;
1666 	int error;
1667 
1668 	ioat = arg1;
1669 
1670 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1671 
1672 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1673 	switch (status) {
1674 	case IOAT_CHANSTS_ACTIVE:
1675 		sbuf_printf(&sb, "ACTIVE");
1676 		break;
1677 	case IOAT_CHANSTS_IDLE:
1678 		sbuf_printf(&sb, "IDLE");
1679 		break;
1680 	case IOAT_CHANSTS_SUSPENDED:
1681 		sbuf_printf(&sb, "SUSPENDED");
1682 		break;
1683 	case IOAT_CHANSTS_HALTED:
1684 		sbuf_printf(&sb, "HALTED");
1685 		break;
1686 	case IOAT_CHANSTS_ARMED:
1687 		sbuf_printf(&sb, "ARMED");
1688 		break;
1689 	default:
1690 		sbuf_printf(&sb, "UNKNOWN");
1691 		break;
1692 	}
1693 	error = sbuf_finish(&sb);
1694 	sbuf_delete(&sb);
1695 
1696 	if (error != 0 || req->newptr == NULL)
1697 		return (error);
1698 	return (EINVAL);
1699 }
1700 
1701 static int
1702 sysctl_handle_dpi(SYSCTL_HANDLER_ARGS)
1703 {
1704 	struct ioat_softc *ioat;
1705 	struct sbuf sb;
1706 #define	PRECISION	"1"
1707 	const uintmax_t factor = 10;
1708 	uintmax_t rate;
1709 	int error;
1710 
1711 	ioat = arg1;
1712 	sbuf_new_for_sysctl(&sb, NULL, 16, req);
1713 
1714 	if (ioat->stats.interrupts == 0) {
1715 		sbuf_printf(&sb, "NaN");
1716 		goto out;
1717 	}
1718 	rate = ioat->stats.descriptors_processed * factor /
1719 	    ioat->stats.interrupts;
1720 	sbuf_printf(&sb, "%ju.%." PRECISION "ju", rate / factor,
1721 	    rate % factor);
1722 #undef	PRECISION
1723 out:
1724 	error = sbuf_finish(&sb);
1725 	sbuf_delete(&sb);
1726 	if (error != 0 || req->newptr == NULL)
1727 		return (error);
1728 	return (EINVAL);
1729 }
1730 
1731 static int
1732 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
1733 {
1734 	struct ioat_softc *ioat;
1735 	int error, arg;
1736 
1737 	ioat = arg1;
1738 
1739 	arg = 0;
1740 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1741 	if (error != 0 || req->newptr == NULL)
1742 		return (error);
1743 
1744 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1745 	if (error != 0)
1746 		return (error);
1747 
1748 	if (arg != 0)
1749 		error = ioat_reset_hw(ioat);
1750 
1751 	return (error);
1752 }
1753 
1754 static void
1755 dump_descriptor(void *hw_desc)
1756 {
1757 	int i, j;
1758 
1759 	for (i = 0; i < 2; i++) {
1760 		for (j = 0; j < 8; j++)
1761 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
1762 		printf("\n");
1763 	}
1764 }
1765 
1766 static void
1767 ioat_setup_sysctl(device_t device)
1768 {
1769 	struct sysctl_oid_list *par, *statpar, *state, *hammer;
1770 	struct sysctl_ctx_list *ctx;
1771 	struct sysctl_oid *tree, *tmp;
1772 	struct ioat_softc *ioat;
1773 
1774 	ioat = DEVICE2SOFTC(device);
1775 	ctx = device_get_sysctl_ctx(device);
1776 	tree = device_get_sysctl_tree(device);
1777 	par = SYSCTL_CHILDREN(tree);
1778 
1779 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
1780 	    &ioat->version, 0, "HW version (0xMM form)");
1781 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
1782 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
1783 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "intrdelay_supported", CTLFLAG_RD,
1784 	    &ioat->intrdelay_supported, 0, "Is INTRDELAY supported");
1785 	SYSCTL_ADD_U16(ctx, par, OID_AUTO, "intrdelay_max", CTLFLAG_RD,
1786 	    &ioat->intrdelay_max, 0,
1787 	    "Maximum configurable INTRDELAY on this channel (microseconds)");
1788 
1789 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "state", CTLFLAG_RD, NULL,
1790 	    "IOAT channel internal state");
1791 	state = SYSCTL_CHILDREN(tmp);
1792 
1793 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "ring_size_order", CTLFLAG_RD,
1794 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
1795 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "head", CTLFLAG_RD, &ioat->head,
1796 	    0, "SW descriptor head pointer index");
1797 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail,
1798 	    0, "SW descriptor tail pointer index");
1799 	SYSCTL_ADD_UINT(ctx, state, OID_AUTO, "hw_head", CTLFLAG_RD,
1800 	    &ioat->hw_head, 0, "HW DMACOUNT");
1801 
1802 	SYSCTL_ADD_UQUAD(ctx, state, OID_AUTO, "last_completion", CTLFLAG_RD,
1803 	    ioat->comp_update, "HW addr of last completion");
1804 
1805 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_submitter_processing",
1806 	    CTLFLAG_RD, &ioat->is_submitter_processing, 0,
1807 	    "submitter processing");
1808 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_completion_pending",
1809 	    CTLFLAG_RD, &ioat->is_completion_pending, 0, "completion pending");
1810 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_reset_pending", CTLFLAG_RD,
1811 	    &ioat->is_reset_pending, 0, "reset pending");
1812 	SYSCTL_ADD_INT(ctx, state, OID_AUTO, "is_channel_running", CTLFLAG_RD,
1813 	    &ioat->is_channel_running, 0, "channel running");
1814 
1815 	SYSCTL_ADD_PROC(ctx, state, OID_AUTO, "chansts",
1816 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
1817 	    "String of the channel status");
1818 
1819 	SYSCTL_ADD_U16(ctx, state, OID_AUTO, "intrdelay", CTLFLAG_RD,
1820 	    &ioat->cached_intrdelay, 0,
1821 	    "Current INTRDELAY on this channel (cached, microseconds)");
1822 
1823 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "hammer", CTLFLAG_RD, NULL,
1824 	    "Big hammers (mostly for testing)");
1825 	hammer = SYSCTL_CHILDREN(tmp);
1826 
1827 	SYSCTL_ADD_PROC(ctx, hammer, OID_AUTO, "force_hw_reset",
1828 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
1829 	    "Set to non-zero to reset the hardware");
1830 
1831 	tmp = SYSCTL_ADD_NODE(ctx, par, OID_AUTO, "stats", CTLFLAG_RD, NULL,
1832 	    "IOAT channel statistics");
1833 	statpar = SYSCTL_CHILDREN(tmp);
1834 
1835 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "interrupts", CTLFLAG_RW,
1836 	    &ioat->stats.interrupts,
1837 	    "Number of interrupts processed on this channel");
1838 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "descriptors", CTLFLAG_RW,
1839 	    &ioat->stats.descriptors_processed,
1840 	    "Number of descriptors processed on this channel");
1841 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "submitted", CTLFLAG_RW,
1842 	    &ioat->stats.descriptors_submitted,
1843 	    "Number of descriptors submitted to this channel");
1844 	SYSCTL_ADD_UQUAD(ctx, statpar, OID_AUTO, "errored", CTLFLAG_RW,
1845 	    &ioat->stats.descriptors_error,
1846 	    "Number of descriptors failed by channel errors");
1847 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "halts", CTLFLAG_RW,
1848 	    &ioat->stats.channel_halts, 0,
1849 	    "Number of times the channel has halted");
1850 	SYSCTL_ADD_U32(ctx, statpar, OID_AUTO, "last_halt_chanerr", CTLFLAG_RW,
1851 	    &ioat->stats.last_halt_chanerr, 0,
1852 	    "The raw CHANERR when the channel was last halted");
1853 
1854 	SYSCTL_ADD_PROC(ctx, statpar, OID_AUTO, "desc_per_interrupt",
1855 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_dpi, "A",
1856 	    "Descriptors per interrupt");
1857 }
1858 
1859 static inline struct ioat_softc *
1860 ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1861 {
1862 	uint32_t old;
1863 
1864 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1865 
1866 	old = atomic_fetchadd_32(&ioat->refcnt, 1);
1867 	KASSERT(old < UINT32_MAX, ("refcnt overflow"));
1868 
1869 #ifdef INVARIANTS
1870 	old = atomic_fetchadd_32(&ioat->refkinds[kind], 1);
1871 	KASSERT(old < UINT32_MAX, ("refcnt kind overflow"));
1872 #endif
1873 
1874 	return (ioat);
1875 }
1876 
1877 static inline void
1878 ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1879 {
1880 
1881 	_ioat_putn(ioat, n, kind, FALSE);
1882 }
1883 
1884 static inline void
1885 ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1886 {
1887 
1888 	_ioat_putn(ioat, n, kind, TRUE);
1889 }
1890 
1891 static inline void
1892 _ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
1893     boolean_t locked)
1894 {
1895 	uint32_t old;
1896 
1897 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1898 
1899 	if (n == 0)
1900 		return;
1901 
1902 #ifdef INVARIANTS
1903 	old = atomic_fetchadd_32(&ioat->refkinds[kind], -n);
1904 	KASSERT(old >= n, ("refcnt kind underflow"));
1905 #endif
1906 
1907 	/* Skip acquiring the lock if resulting refcnt > 0. */
1908 	for (;;) {
1909 		old = ioat->refcnt;
1910 		if (old <= n)
1911 			break;
1912 		if (atomic_cmpset_32(&ioat->refcnt, old, old - n))
1913 			return;
1914 	}
1915 
1916 	if (locked)
1917 		mtx_assert(IOAT_REFLK, MA_OWNED);
1918 	else
1919 		mtx_lock(IOAT_REFLK);
1920 
1921 	old = atomic_fetchadd_32(&ioat->refcnt, -n);
1922 	KASSERT(old >= n, ("refcnt error"));
1923 
1924 	if (old == n)
1925 		wakeup(IOAT_REFLK);
1926 	if (!locked)
1927 		mtx_unlock(IOAT_REFLK);
1928 }
1929 
1930 static inline void
1931 ioat_put(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1932 {
1933 
1934 	ioat_putn(ioat, 1, kind);
1935 }
1936 
1937 static void
1938 ioat_drain_locked(struct ioat_softc *ioat)
1939 {
1940 
1941 	mtx_assert(IOAT_REFLK, MA_OWNED);
1942 	while (ioat->refcnt > 0)
1943 		msleep(IOAT_REFLK, IOAT_REFLK, 0, "ioat_drain", 0);
1944 }
1945 
1946 #ifdef DDB
1947 #define	_db_show_lock(lo)	LOCK_CLASS(lo)->lc_ddb_show(lo)
1948 #define	db_show_lock(lk)	_db_show_lock(&(lk)->lock_object)
1949 DB_SHOW_COMMAND(ioat, db_show_ioat)
1950 {
1951 	struct ioat_softc *sc;
1952 	unsigned idx;
1953 
1954 	if (!have_addr)
1955 		goto usage;
1956 	idx = (unsigned)addr;
1957 	if (idx >= ioat_channel_index)
1958 		goto usage;
1959 
1960 	sc = ioat_channel[idx];
1961 	db_printf("ioat softc at %p\n", sc);
1962 	if (sc == NULL)
1963 		return;
1964 
1965 	db_printf(" version: %d\n", sc->version);
1966 	db_printf(" chan_idx: %u\n", sc->chan_idx);
1967 	db_printf(" submit_lock: ");
1968 	db_show_lock(&sc->submit_lock);
1969 
1970 	db_printf(" capabilities: %b\n", (int)sc->capabilities,
1971 	    IOAT_DMACAP_STR);
1972 	db_printf(" cached_intrdelay: %u\n", sc->cached_intrdelay);
1973 	db_printf(" *comp_update: 0x%jx\n", (uintmax_t)*sc->comp_update);
1974 
1975 	db_printf(" poll_timer:\n");
1976 	db_printf("  c_time: %ju\n", (uintmax_t)sc->poll_timer.c_time);
1977 	db_printf("  c_arg: %p\n", sc->poll_timer.c_arg);
1978 	db_printf("  c_func: %p\n", sc->poll_timer.c_func);
1979 	db_printf("  c_lock: %p\n", sc->poll_timer.c_lock);
1980 	db_printf("  c_flags: 0x%x\n", (unsigned)sc->poll_timer.c_flags);
1981 
1982 	db_printf(" quiescing: %d\n", (int)sc->quiescing);
1983 	db_printf(" destroying: %d\n", (int)sc->destroying);
1984 	db_printf(" is_submitter_processing: %d\n",
1985 	    (int)sc->is_submitter_processing);
1986 	db_printf(" is_completion_pending: %d\n", (int)sc->is_completion_pending);
1987 	db_printf(" is_reset_pending: %d\n", (int)sc->is_reset_pending);
1988 	db_printf(" is_channel_running: %d\n", (int)sc->is_channel_running);
1989 	db_printf(" intrdelay_supported: %d\n", (int)sc->intrdelay_supported);
1990 	db_printf(" resetting: %d\n", (int)sc->resetting);
1991 
1992 	db_printf(" head: %u\n", sc->head);
1993 	db_printf(" tail: %u\n", sc->tail);
1994 	db_printf(" hw_head: %u\n", sc->hw_head);
1995 	db_printf(" ring_size_order: %u\n", sc->ring_size_order);
1996 	db_printf(" last_seen: 0x%lx\n", sc->last_seen);
1997 	db_printf(" ring: %p\n", sc->ring);
1998 	db_printf(" descriptors: %p\n", sc->hw_desc_ring);
1999 	db_printf(" descriptors (phys): 0x%jx\n",
2000 	    (uintmax_t)sc->hw_desc_bus_addr);
2001 
2002 	db_printf("  ring[%u] (tail):\n", sc->tail %
2003 	    (1 << sc->ring_size_order));
2004 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->tail)->id);
2005 	db_printf("   addr: 0x%lx\n",
2006 	    RING_PHYS_ADDR(sc, sc->tail));
2007 	db_printf("   next: 0x%lx\n",
2008 	     ioat_get_descriptor(sc, sc->tail)->generic.next);
2009 
2010 	db_printf("  ring[%u] (head - 1):\n", (sc->head - 1) %
2011 	    (1 << sc->ring_size_order));
2012 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head - 1)->id);
2013 	db_printf("   addr: 0x%lx\n",
2014 	    RING_PHYS_ADDR(sc, sc->head - 1));
2015 	db_printf("   next: 0x%lx\n",
2016 	     ioat_get_descriptor(sc, sc->head - 1)->generic.next);
2017 
2018 	db_printf("  ring[%u] (head):\n", (sc->head) %
2019 	    (1 << sc->ring_size_order));
2020 	db_printf("   id: %u\n", ioat_get_ring_entry(sc, sc->head)->id);
2021 	db_printf("   addr: 0x%lx\n",
2022 	    RING_PHYS_ADDR(sc, sc->head));
2023 	db_printf("   next: 0x%lx\n",
2024 	     ioat_get_descriptor(sc, sc->head)->generic.next);
2025 
2026 	for (idx = 0; idx < (1 << sc->ring_size_order); idx++)
2027 		if ((*sc->comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK)
2028 		    == RING_PHYS_ADDR(sc, idx))
2029 			db_printf("  ring[%u] == hardware tail\n", idx);
2030 
2031 	db_printf(" cleanup_lock: ");
2032 	db_show_lock(&sc->cleanup_lock);
2033 
2034 	db_printf(" refcnt: %u\n", sc->refcnt);
2035 #ifdef INVARIANTS
2036 	CTASSERT(IOAT_NUM_REF_KINDS == 2);
2037 	db_printf(" refkinds: [ENG=%u, DESCR=%u]\n", sc->refkinds[0],
2038 	    sc->refkinds[1]);
2039 #endif
2040 	db_printf(" stats:\n");
2041 	db_printf("  interrupts: %lu\n", sc->stats.interrupts);
2042 	db_printf("  descriptors_processed: %lu\n", sc->stats.descriptors_processed);
2043 	db_printf("  descriptors_error: %lu\n", sc->stats.descriptors_error);
2044 	db_printf("  descriptors_submitted: %lu\n", sc->stats.descriptors_submitted);
2045 
2046 	db_printf("  channel_halts: %u\n", sc->stats.channel_halts);
2047 	db_printf("  last_halt_chanerr: %u\n", sc->stats.last_halt_chanerr);
2048 
2049 	if (db_pager_quit)
2050 		return;
2051 
2052 	db_printf(" hw status:\n");
2053 	db_printf("  status: 0x%lx\n", ioat_get_chansts(sc));
2054 	db_printf("  chanctrl: 0x%x\n",
2055 	    (unsigned)ioat_read_2(sc, IOAT_CHANCTRL_OFFSET));
2056 	db_printf("  chancmd: 0x%x\n",
2057 	    (unsigned)ioat_read_1(sc, IOAT_CHANCMD_OFFSET));
2058 	db_printf("  dmacount: 0x%x\n",
2059 	    (unsigned)ioat_read_2(sc, IOAT_DMACOUNT_OFFSET));
2060 	db_printf("  chainaddr: 0x%lx\n",
2061 	    ioat_read_double_4(sc, IOAT_CHAINADDR_OFFSET_LOW));
2062 	db_printf("  chancmp: 0x%lx\n",
2063 	    ioat_read_double_4(sc, IOAT_CHANCMP_OFFSET_LOW));
2064 	db_printf("  chanerr: %b\n",
2065 	    (int)ioat_read_4(sc, IOAT_CHANERR_OFFSET), IOAT_CHANERR_STR);
2066 	return;
2067 usage:
2068 	db_printf("usage: show ioat <0-%u>\n", ioat_channel_index);
2069 	return;
2070 }
2071 #endif /* DDB */
2072