xref: /freebsd/sys/dev/ioat/ioat.c (revision fc7284da06408923f7850a0e4e954a903b8ee038)
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 <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <sys/ioccom.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/rman.h>
41 #include <sys/sbuf.h>
42 #include <sys/sysctl.h>
43 #include <sys/time.h>
44 #include <dev/pci/pcireg.h>
45 #include <dev/pci/pcivar.h>
46 #include <machine/bus.h>
47 #include <machine/resource.h>
48 #include <machine/stdarg.h>
49 
50 #include "ioat.h"
51 #include "ioat_hw.h"
52 #include "ioat_internal.h"
53 
54 #define	IOAT_INTR_TIMO	(hz / 10)
55 #define	IOAT_REFLK	(&ioat->submit_lock)
56 
57 static int ioat_probe(device_t device);
58 static int ioat_attach(device_t device);
59 static int ioat_detach(device_t device);
60 static int ioat_setup_intr(struct ioat_softc *ioat);
61 static int ioat_teardown_intr(struct ioat_softc *ioat);
62 static int ioat3_attach(device_t device);
63 static int ioat_start_channel(struct ioat_softc *ioat);
64 static int ioat_map_pci_bar(struct ioat_softc *ioat);
65 static void ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg,
66     int error);
67 static void ioat_interrupt_handler(void *arg);
68 static boolean_t ioat_model_resets_msix(struct ioat_softc *ioat);
69 static int chanerr_to_errno(uint32_t);
70 static void ioat_process_events(struct ioat_softc *ioat);
71 static inline uint32_t ioat_get_active(struct ioat_softc *ioat);
72 static inline uint32_t ioat_get_ring_space(struct ioat_softc *ioat);
73 static void ioat_free_ring(struct ioat_softc *, uint32_t size,
74     struct ioat_descriptor **);
75 static void ioat_free_ring_entry(struct ioat_softc *ioat,
76     struct ioat_descriptor *desc);
77 static struct ioat_descriptor *ioat_alloc_ring_entry(struct ioat_softc *,
78     int mflags);
79 static int ioat_reserve_space(struct ioat_softc *, uint32_t, int mflags);
80 static struct ioat_descriptor *ioat_get_ring_entry(struct ioat_softc *ioat,
81     uint32_t index);
82 static struct ioat_descriptor **ioat_prealloc_ring(struct ioat_softc *,
83     uint32_t size, boolean_t need_dscr, int mflags);
84 static int ring_grow(struct ioat_softc *, uint32_t oldorder,
85     struct ioat_descriptor **);
86 static int ring_shrink(struct ioat_softc *, uint32_t oldorder,
87     struct ioat_descriptor **);
88 static void ioat_halted_debug(struct ioat_softc *, uint32_t);
89 static void ioat_timer_callback(void *arg);
90 static void dump_descriptor(void *hw_desc);
91 static void ioat_submit_single(struct ioat_softc *ioat);
92 static void ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg,
93     int error);
94 static int ioat_reset_hw(struct ioat_softc *ioat);
95 static void ioat_setup_sysctl(device_t device);
96 static int sysctl_handle_reset(SYSCTL_HANDLER_ARGS);
97 static inline struct ioat_softc *ioat_get(struct ioat_softc *,
98     enum ioat_ref_kind);
99 static inline void ioat_put(struct ioat_softc *, enum ioat_ref_kind);
100 static inline void _ioat_putn(struct ioat_softc *, uint32_t,
101     enum ioat_ref_kind, boolean_t);
102 static inline void ioat_putn(struct ioat_softc *, uint32_t,
103     enum ioat_ref_kind);
104 static inline void ioat_putn_locked(struct ioat_softc *, uint32_t,
105     enum ioat_ref_kind);
106 static void ioat_drain_locked(struct ioat_softc *);
107 
108 #define	ioat_log_message(v, ...) do {					\
109 	if ((v) <= g_ioat_debug_level) {				\
110 		device_printf(ioat->device, __VA_ARGS__);		\
111 	}								\
112 } while (0)
113 
114 MALLOC_DEFINE(M_IOAT, "ioat", "ioat driver memory allocations");
115 SYSCTL_NODE(_hw, OID_AUTO, ioat, CTLFLAG_RD, 0, "ioat node");
116 
117 static int g_force_legacy_interrupts;
118 SYSCTL_INT(_hw_ioat, OID_AUTO, force_legacy_interrupts, CTLFLAG_RDTUN,
119     &g_force_legacy_interrupts, 0, "Set to non-zero to force MSI-X disabled");
120 
121 int g_ioat_debug_level = 0;
122 SYSCTL_INT(_hw_ioat, OID_AUTO, debug_level, CTLFLAG_RWTUN, &g_ioat_debug_level,
123     0, "Set log level (0-3) for ioat(4). Higher is more verbose.");
124 
125 /*
126  * OS <-> Driver interface structures
127  */
128 static device_method_t ioat_pci_methods[] = {
129 	/* Device interface */
130 	DEVMETHOD(device_probe,     ioat_probe),
131 	DEVMETHOD(device_attach,    ioat_attach),
132 	DEVMETHOD(device_detach,    ioat_detach),
133 	{ 0, 0 }
134 };
135 
136 static driver_t ioat_pci_driver = {
137 	"ioat",
138 	ioat_pci_methods,
139 	sizeof(struct ioat_softc),
140 };
141 
142 static devclass_t ioat_devclass;
143 DRIVER_MODULE(ioat, pci, ioat_pci_driver, ioat_devclass, 0, 0);
144 MODULE_VERSION(ioat, 1);
145 
146 /*
147  * Private data structures
148  */
149 static struct ioat_softc *ioat_channel[IOAT_MAX_CHANNELS];
150 static int ioat_channel_index = 0;
151 SYSCTL_INT(_hw_ioat, OID_AUTO, channels, CTLFLAG_RD, &ioat_channel_index, 0,
152     "Number of IOAT channels attached");
153 
154 static struct _pcsid
155 {
156 	u_int32_t   type;
157 	const char  *desc;
158 } pci_ids[] = {
159 	{ 0x34308086, "TBG IOAT Ch0" },
160 	{ 0x34318086, "TBG IOAT Ch1" },
161 	{ 0x34328086, "TBG IOAT Ch2" },
162 	{ 0x34338086, "TBG IOAT Ch3" },
163 	{ 0x34298086, "TBG IOAT Ch4" },
164 	{ 0x342a8086, "TBG IOAT Ch5" },
165 	{ 0x342b8086, "TBG IOAT Ch6" },
166 	{ 0x342c8086, "TBG IOAT Ch7" },
167 
168 	{ 0x37108086, "JSF IOAT Ch0" },
169 	{ 0x37118086, "JSF IOAT Ch1" },
170 	{ 0x37128086, "JSF IOAT Ch2" },
171 	{ 0x37138086, "JSF IOAT Ch3" },
172 	{ 0x37148086, "JSF IOAT Ch4" },
173 	{ 0x37158086, "JSF IOAT Ch5" },
174 	{ 0x37168086, "JSF IOAT Ch6" },
175 	{ 0x37178086, "JSF IOAT Ch7" },
176 	{ 0x37188086, "JSF IOAT Ch0 (RAID)" },
177 	{ 0x37198086, "JSF IOAT Ch1 (RAID)" },
178 
179 	{ 0x3c208086, "SNB IOAT Ch0" },
180 	{ 0x3c218086, "SNB IOAT Ch1" },
181 	{ 0x3c228086, "SNB IOAT Ch2" },
182 	{ 0x3c238086, "SNB IOAT Ch3" },
183 	{ 0x3c248086, "SNB IOAT Ch4" },
184 	{ 0x3c258086, "SNB IOAT Ch5" },
185 	{ 0x3c268086, "SNB IOAT Ch6" },
186 	{ 0x3c278086, "SNB IOAT Ch7" },
187 	{ 0x3c2e8086, "SNB IOAT Ch0 (RAID)" },
188 	{ 0x3c2f8086, "SNB IOAT Ch1 (RAID)" },
189 
190 	{ 0x0e208086, "IVB IOAT Ch0" },
191 	{ 0x0e218086, "IVB IOAT Ch1" },
192 	{ 0x0e228086, "IVB IOAT Ch2" },
193 	{ 0x0e238086, "IVB IOAT Ch3" },
194 	{ 0x0e248086, "IVB IOAT Ch4" },
195 	{ 0x0e258086, "IVB IOAT Ch5" },
196 	{ 0x0e268086, "IVB IOAT Ch6" },
197 	{ 0x0e278086, "IVB IOAT Ch7" },
198 	{ 0x0e2e8086, "IVB IOAT Ch0 (RAID)" },
199 	{ 0x0e2f8086, "IVB IOAT Ch1 (RAID)" },
200 
201 	{ 0x2f208086, "HSW IOAT Ch0" },
202 	{ 0x2f218086, "HSW IOAT Ch1" },
203 	{ 0x2f228086, "HSW IOAT Ch2" },
204 	{ 0x2f238086, "HSW IOAT Ch3" },
205 	{ 0x2f248086, "HSW IOAT Ch4" },
206 	{ 0x2f258086, "HSW IOAT Ch5" },
207 	{ 0x2f268086, "HSW IOAT Ch6" },
208 	{ 0x2f278086, "HSW IOAT Ch7" },
209 	{ 0x2f2e8086, "HSW IOAT Ch0 (RAID)" },
210 	{ 0x2f2f8086, "HSW IOAT Ch1 (RAID)" },
211 
212 	{ 0x0c508086, "BWD IOAT Ch0" },
213 	{ 0x0c518086, "BWD IOAT Ch1" },
214 	{ 0x0c528086, "BWD IOAT Ch2" },
215 	{ 0x0c538086, "BWD IOAT Ch3" },
216 
217 	{ 0x6f508086, "BDXDE IOAT Ch0" },
218 	{ 0x6f518086, "BDXDE IOAT Ch1" },
219 	{ 0x6f528086, "BDXDE IOAT Ch2" },
220 	{ 0x6f538086, "BDXDE IOAT Ch3" },
221 
222 	{ 0x00000000, NULL           }
223 };
224 
225 /*
226  * OS <-> Driver linkage functions
227  */
228 static int
229 ioat_probe(device_t device)
230 {
231 	struct _pcsid *ep;
232 	u_int32_t type;
233 
234 	type = pci_get_devid(device);
235 	for (ep = pci_ids; ep->type; ep++) {
236 		if (ep->type == type) {
237 			device_set_desc(device, ep->desc);
238 			return (0);
239 		}
240 	}
241 	return (ENXIO);
242 }
243 
244 static int
245 ioat_attach(device_t device)
246 {
247 	struct ioat_softc *ioat;
248 	int error;
249 
250 	ioat = DEVICE2SOFTC(device);
251 	ioat->device = device;
252 
253 	error = ioat_map_pci_bar(ioat);
254 	if (error != 0)
255 		goto err;
256 
257 	ioat->version = ioat_read_cbver(ioat);
258 	if (ioat->version < IOAT_VER_3_0) {
259 		error = ENODEV;
260 		goto err;
261 	}
262 
263 	error = ioat3_attach(device);
264 	if (error != 0)
265 		goto err;
266 
267 	error = pci_enable_busmaster(device);
268 	if (error != 0)
269 		goto err;
270 
271 	error = ioat_setup_intr(ioat);
272 	if (error != 0)
273 		goto err;
274 
275 	error = ioat_reset_hw(ioat);
276 	if (error != 0)
277 		goto err;
278 
279 	ioat_process_events(ioat);
280 	ioat_setup_sysctl(device);
281 
282 	ioat->chan_idx = ioat_channel_index;
283 	ioat_channel[ioat_channel_index++] = ioat;
284 	ioat_test_attach();
285 
286 err:
287 	if (error != 0)
288 		ioat_detach(device);
289 	return (error);
290 }
291 
292 static int
293 ioat_detach(device_t device)
294 {
295 	struct ioat_softc *ioat;
296 
297 	ioat = DEVICE2SOFTC(device);
298 
299 	ioat_test_detach();
300 
301 	mtx_lock(IOAT_REFLK);
302 	ioat->quiescing = TRUE;
303 	ioat_channel[ioat->chan_idx] = NULL;
304 
305 	ioat_drain_locked(ioat);
306 	mtx_unlock(IOAT_REFLK);
307 
308 	ioat_teardown_intr(ioat);
309 	callout_drain(&ioat->timer);
310 
311 	pci_disable_busmaster(device);
312 
313 	if (ioat->pci_resource != NULL)
314 		bus_release_resource(device, SYS_RES_MEMORY,
315 		    ioat->pci_resource_id, ioat->pci_resource);
316 
317 	if (ioat->ring != NULL)
318 		ioat_free_ring(ioat, 1 << ioat->ring_size_order, ioat->ring);
319 
320 	if (ioat->comp_update != NULL) {
321 		bus_dmamap_unload(ioat->comp_update_tag, ioat->comp_update_map);
322 		bus_dmamem_free(ioat->comp_update_tag, ioat->comp_update,
323 		    ioat->comp_update_map);
324 		bus_dma_tag_destroy(ioat->comp_update_tag);
325 	}
326 
327 	bus_dma_tag_destroy(ioat->hw_desc_tag);
328 
329 	return (0);
330 }
331 
332 static int
333 ioat_teardown_intr(struct ioat_softc *ioat)
334 {
335 
336 	if (ioat->tag != NULL)
337 		bus_teardown_intr(ioat->device, ioat->res, ioat->tag);
338 
339 	if (ioat->res != NULL)
340 		bus_release_resource(ioat->device, SYS_RES_IRQ,
341 		    rman_get_rid(ioat->res), ioat->res);
342 
343 	pci_release_msi(ioat->device);
344 	return (0);
345 }
346 
347 static int
348 ioat_start_channel(struct ioat_softc *ioat)
349 {
350 	uint64_t status;
351 	uint32_t chanerr;
352 	int i;
353 
354 	ioat_acquire(&ioat->dmaengine);
355 	ioat_null(&ioat->dmaengine, NULL, NULL, 0);
356 	ioat_release(&ioat->dmaengine);
357 
358 	for (i = 0; i < 100; i++) {
359 		DELAY(1);
360 		status = ioat_get_chansts(ioat);
361 		if (is_ioat_idle(status))
362 			return (0);
363 	}
364 
365 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
366 	ioat_log_message(0, "could not start channel: "
367 	    "status = %#jx error = %b\n", (uintmax_t)status, (int)chanerr,
368 	    IOAT_CHANERR_STR);
369 	return (ENXIO);
370 }
371 
372 /*
373  * Initialize Hardware
374  */
375 static int
376 ioat3_attach(device_t device)
377 {
378 	struct ioat_softc *ioat;
379 	struct ioat_descriptor **ring;
380 	struct ioat_descriptor *next;
381 	struct ioat_dma_hw_descriptor *dma_hw_desc;
382 	int i, num_descriptors;
383 	int error;
384 	uint8_t xfercap;
385 
386 	error = 0;
387 	ioat = DEVICE2SOFTC(device);
388 	ioat->capabilities = ioat_read_dmacapability(ioat);
389 
390 	ioat_log_message(1, "Capabilities: %b\n", (int)ioat->capabilities,
391 	    IOAT_DMACAP_STR);
392 
393 	xfercap = ioat_read_xfercap(ioat);
394 	ioat->max_xfer_size = 1 << xfercap;
395 
396 	/* TODO: need to check DCA here if we ever do XOR/PQ */
397 
398 	mtx_init(&ioat->submit_lock, "ioat_submit", NULL, MTX_DEF);
399 	mtx_init(&ioat->cleanup_lock, "ioat_cleanup", NULL, MTX_DEF);
400 	callout_init(&ioat->timer, 1);
401 
402 	/* Establish lock order for Witness */
403 	mtx_lock(&ioat->submit_lock);
404 	mtx_lock(&ioat->cleanup_lock);
405 	mtx_unlock(&ioat->cleanup_lock);
406 	mtx_unlock(&ioat->submit_lock);
407 
408 	ioat->is_resize_pending = FALSE;
409 	ioat->is_completion_pending = FALSE;
410 	ioat->is_reset_pending = FALSE;
411 	ioat->is_channel_running = FALSE;
412 
413 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), sizeof(uint64_t), 0x0,
414 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
415 	    sizeof(uint64_t), 1, sizeof(uint64_t), 0, NULL, NULL,
416 	    &ioat->comp_update_tag);
417 
418 	error = bus_dmamem_alloc(ioat->comp_update_tag,
419 	    (void **)&ioat->comp_update, BUS_DMA_ZERO, &ioat->comp_update_map);
420 	if (ioat->comp_update == NULL)
421 		return (ENOMEM);
422 
423 	error = bus_dmamap_load(ioat->comp_update_tag, ioat->comp_update_map,
424 	    ioat->comp_update, sizeof(uint64_t), ioat_comp_update_map, ioat,
425 	    0);
426 	if (error != 0)
427 		return (error);
428 
429 	ioat->ring_size_order = IOAT_MIN_ORDER;
430 
431 	num_descriptors = 1 << ioat->ring_size_order;
432 
433 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), 0x40, 0x0,
434 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
435 	    sizeof(struct ioat_dma_hw_descriptor), 1,
436 	    sizeof(struct ioat_dma_hw_descriptor), 0, NULL, NULL,
437 	    &ioat->hw_desc_tag);
438 
439 	ioat->ring = malloc(num_descriptors * sizeof(*ring), M_IOAT,
440 	    M_ZERO | M_WAITOK);
441 	if (ioat->ring == NULL)
442 		return (ENOMEM);
443 
444 	ring = ioat->ring;
445 	for (i = 0; i < num_descriptors; i++) {
446 		ring[i] = ioat_alloc_ring_entry(ioat, M_WAITOK);
447 		if (ring[i] == NULL)
448 			return (ENOMEM);
449 
450 		ring[i]->id = i;
451 	}
452 
453 	for (i = 0; i < num_descriptors - 1; i++) {
454 		next = ring[i + 1];
455 		dma_hw_desc = ring[i]->u.dma;
456 
457 		dma_hw_desc->next = next->hw_desc_bus_addr;
458 	}
459 
460 	ring[i]->u.dma->next = ring[0]->hw_desc_bus_addr;
461 
462 	ioat->head = ioat->hw_head = 0;
463 	ioat->tail = 0;
464 	ioat->last_seen = 0;
465 	return (0);
466 }
467 
468 static int
469 ioat_map_pci_bar(struct ioat_softc *ioat)
470 {
471 
472 	ioat->pci_resource_id = PCIR_BAR(0);
473 	ioat->pci_resource = bus_alloc_resource_any(ioat->device,
474 	    SYS_RES_MEMORY, &ioat->pci_resource_id, RF_ACTIVE);
475 
476 	if (ioat->pci_resource == NULL) {
477 		ioat_log_message(0, "unable to allocate pci resource\n");
478 		return (ENODEV);
479 	}
480 
481 	ioat->pci_bus_tag = rman_get_bustag(ioat->pci_resource);
482 	ioat->pci_bus_handle = rman_get_bushandle(ioat->pci_resource);
483 	return (0);
484 }
485 
486 static void
487 ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
488 {
489 	struct ioat_softc *ioat = arg;
490 
491 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
492 	ioat->comp_update_bus_addr = seg[0].ds_addr;
493 }
494 
495 static void
496 ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
497 {
498 	bus_addr_t *baddr;
499 
500 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
501 	baddr = arg;
502 	*baddr = segs->ds_addr;
503 }
504 
505 /*
506  * Interrupt setup and handlers
507  */
508 static int
509 ioat_setup_intr(struct ioat_softc *ioat)
510 {
511 	uint32_t num_vectors;
512 	int error;
513 	boolean_t use_msix;
514 	boolean_t force_legacy_interrupts;
515 
516 	use_msix = FALSE;
517 	force_legacy_interrupts = FALSE;
518 
519 	if (!g_force_legacy_interrupts && pci_msix_count(ioat->device) >= 1) {
520 		num_vectors = 1;
521 		pci_alloc_msix(ioat->device, &num_vectors);
522 		if (num_vectors == 1)
523 			use_msix = TRUE;
524 	}
525 
526 	if (use_msix) {
527 		ioat->rid = 1;
528 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
529 		    &ioat->rid, RF_ACTIVE);
530 	} else {
531 		ioat->rid = 0;
532 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
533 		    &ioat->rid, RF_SHAREABLE | RF_ACTIVE);
534 	}
535 	if (ioat->res == NULL) {
536 		ioat_log_message(0, "bus_alloc_resource failed\n");
537 		return (ENOMEM);
538 	}
539 
540 	ioat->tag = NULL;
541 	error = bus_setup_intr(ioat->device, ioat->res, INTR_MPSAFE |
542 	    INTR_TYPE_MISC, NULL, ioat_interrupt_handler, ioat, &ioat->tag);
543 	if (error != 0) {
544 		ioat_log_message(0, "bus_setup_intr failed\n");
545 		return (error);
546 	}
547 
548 	ioat_write_intrctrl(ioat, IOAT_INTRCTRL_MASTER_INT_EN);
549 	return (0);
550 }
551 
552 static boolean_t
553 ioat_model_resets_msix(struct ioat_softc *ioat)
554 {
555 	u_int32_t pciid;
556 
557 	pciid = pci_get_devid(ioat->device);
558 	switch (pciid) {
559 		/* BWD: */
560 	case 0x0c508086:
561 	case 0x0c518086:
562 	case 0x0c528086:
563 	case 0x0c538086:
564 		/* BDXDE: */
565 	case 0x6f508086:
566 	case 0x6f518086:
567 	case 0x6f528086:
568 	case 0x6f538086:
569 		return (TRUE);
570 	}
571 
572 	return (FALSE);
573 }
574 
575 static void
576 ioat_interrupt_handler(void *arg)
577 {
578 	struct ioat_softc *ioat = arg;
579 
580 	ioat_process_events(ioat);
581 }
582 
583 static int
584 chanerr_to_errno(uint32_t chanerr)
585 {
586 
587 	if (chanerr == 0)
588 		return (0);
589 	if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
590 		return (EFAULT);
591 	if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
592 		return (EIO);
593 	/* This one is probably our fault: */
594 	if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
595 		return (EIO);
596 	return (EIO);
597 }
598 
599 static void
600 ioat_process_events(struct ioat_softc *ioat)
601 {
602 	struct ioat_descriptor *desc;
603 	struct bus_dmadesc *dmadesc;
604 	uint64_t comp_update, status;
605 	uint32_t completed, chanerr;
606 	int error;
607 
608 	mtx_lock(&ioat->cleanup_lock);
609 
610 	completed = 0;
611 	comp_update = *ioat->comp_update;
612 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
613 
614 	CTR0(KTR_IOAT, __func__);
615 
616 	if (status == ioat->last_seen)
617 		goto out;
618 
619 	while (1) {
620 		desc = ioat_get_ring_entry(ioat, ioat->tail);
621 		dmadesc = &desc->bus_dmadesc;
622 		CTR1(KTR_IOAT, "completing desc %d", ioat->tail);
623 
624 		if (dmadesc->callback_fn != NULL)
625 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
626 
627 		completed++;
628 		ioat->tail++;
629 		if (desc->hw_desc_bus_addr == status)
630 			break;
631 	}
632 
633 	ioat->last_seen = desc->hw_desc_bus_addr;
634 
635 	if (ioat->head == ioat->tail) {
636 		ioat->is_completion_pending = FALSE;
637 		callout_reset(&ioat->timer, IOAT_INTR_TIMO,
638 		    ioat_timer_callback, ioat);
639 	}
640 
641 out:
642 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
643 	mtx_unlock(&ioat->cleanup_lock);
644 
645 	ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
646 	wakeup(&ioat->tail);
647 
648 	if (!is_ioat_halted(comp_update))
649 		return;
650 
651 	/*
652 	 * Fatal programming error on this DMA channel.  Flush any outstanding
653 	 * work with error status and restart the engine.
654 	 */
655 	ioat_log_message(0, "Channel halted due to fatal programming error\n");
656 	mtx_lock(&ioat->submit_lock);
657 	mtx_lock(&ioat->cleanup_lock);
658 	ioat->quiescing = TRUE;
659 
660 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
661 	ioat_halted_debug(ioat, chanerr);
662 
663 	while (ioat_get_active(ioat) > 0) {
664 		desc = ioat_get_ring_entry(ioat, ioat->tail);
665 		dmadesc = &desc->bus_dmadesc;
666 		CTR1(KTR_IOAT, "completing err desc %d", ioat->tail);
667 
668 		if (dmadesc->callback_fn != NULL)
669 			dmadesc->callback_fn(dmadesc->callback_arg,
670 			    chanerr_to_errno(chanerr));
671 
672 		ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
673 		ioat->tail++;
674 	}
675 
676 	/* Clear error status */
677 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
678 
679 	mtx_unlock(&ioat->cleanup_lock);
680 	mtx_unlock(&ioat->submit_lock);
681 
682 	ioat_log_message(0, "Resetting channel to recover from error\n");
683 	error = ioat_reset_hw(ioat);
684 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
685 }
686 
687 /*
688  * User API functions
689  */
690 bus_dmaengine_t
691 ioat_get_dmaengine(uint32_t index)
692 {
693 	struct ioat_softc *sc;
694 
695 	if (index >= ioat_channel_index)
696 		return (NULL);
697 
698 	sc = ioat_channel[index];
699 	if (sc == NULL || sc->quiescing)
700 		return (NULL);
701 
702 	return (&ioat_get(sc, IOAT_DMAENGINE_REF)->dmaengine);
703 }
704 
705 void
706 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
707 {
708 	struct ioat_softc *ioat;
709 
710 	ioat = to_ioat_softc(dmaengine);
711 	ioat_put(ioat, IOAT_DMAENGINE_REF);
712 }
713 
714 void
715 ioat_acquire(bus_dmaengine_t dmaengine)
716 {
717 	struct ioat_softc *ioat;
718 
719 	ioat = to_ioat_softc(dmaengine);
720 	mtx_lock(&ioat->submit_lock);
721 	CTR0(KTR_IOAT, __func__);
722 }
723 
724 void
725 ioat_release(bus_dmaengine_t dmaengine)
726 {
727 	struct ioat_softc *ioat;
728 
729 	ioat = to_ioat_softc(dmaengine);
730 	CTR0(KTR_IOAT, __func__);
731 	ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET, (uint16_t)ioat->hw_head);
732 	mtx_unlock(&ioat->submit_lock);
733 }
734 
735 static struct ioat_descriptor *
736 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
737     uint32_t size, uint64_t src, uint64_t dst,
738     bus_dmaengine_callback_t callback_fn, void *callback_arg,
739     uint32_t flags)
740 {
741 	struct ioat_generic_hw_descriptor *hw_desc;
742 	struct ioat_descriptor *desc;
743 	int mflags;
744 
745 	mtx_assert(&ioat->submit_lock, MA_OWNED);
746 
747 	KASSERT((flags & ~DMA_ALL_FLAGS) == 0, ("Unrecognized flag(s): %#x",
748 		flags & ~DMA_ALL_FLAGS));
749 	if ((flags & DMA_NO_WAIT) != 0)
750 		mflags = M_NOWAIT;
751 	else
752 		mflags = M_WAITOK;
753 
754 	if (size > ioat->max_xfer_size) {
755 		ioat_log_message(0, "%s: max_xfer_size = %d, requested = %u\n",
756 		    __func__, ioat->max_xfer_size, (unsigned)size);
757 		return (NULL);
758 	}
759 
760 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
761 		return (NULL);
762 
763 	desc = ioat_get_ring_entry(ioat, ioat->head);
764 	hw_desc = desc->u.generic;
765 
766 	hw_desc->u.control_raw = 0;
767 	hw_desc->u.control_generic.op = op;
768 	hw_desc->u.control_generic.completion_update = 1;
769 
770 	if ((flags & DMA_INT_EN) != 0)
771 		hw_desc->u.control_generic.int_enable = 1;
772 
773 	hw_desc->size = size;
774 	hw_desc->src_addr = src;
775 	hw_desc->dest_addr = dst;
776 
777 	desc->bus_dmadesc.callback_fn = callback_fn;
778 	desc->bus_dmadesc.callback_arg = callback_arg;
779 	return (desc);
780 }
781 
782 struct bus_dmadesc *
783 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
784     void *callback_arg, uint32_t flags)
785 {
786 	struct ioat_dma_hw_descriptor *hw_desc;
787 	struct ioat_descriptor *desc;
788 	struct ioat_softc *ioat;
789 
790 	CTR0(KTR_IOAT, __func__);
791 	ioat = to_ioat_softc(dmaengine);
792 
793 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
794 	    callback_arg, flags);
795 	if (desc == NULL)
796 		return (NULL);
797 
798 	hw_desc = desc->u.dma;
799 	hw_desc->u.control.null = 1;
800 	ioat_submit_single(ioat);
801 	return (&desc->bus_dmadesc);
802 }
803 
804 struct bus_dmadesc *
805 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
806     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
807     void *callback_arg, uint32_t flags)
808 {
809 	struct ioat_dma_hw_descriptor *hw_desc;
810 	struct ioat_descriptor *desc;
811 	struct ioat_softc *ioat;
812 
813 	CTR0(KTR_IOAT, __func__);
814 	ioat = to_ioat_softc(dmaengine);
815 
816 	if (((src | dst) & (0xffffull << 48)) != 0) {
817 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
818 		    __func__);
819 		return (NULL);
820 	}
821 
822 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
823 	    callback_arg, flags);
824 	if (desc == NULL)
825 		return (NULL);
826 
827 	hw_desc = desc->u.dma;
828 	if (g_ioat_debug_level >= 3)
829 		dump_descriptor(hw_desc);
830 
831 	ioat_submit_single(ioat);
832 	return (&desc->bus_dmadesc);
833 }
834 
835 struct bus_dmadesc *
836 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
837     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
838     uint32_t flags)
839 {
840 	struct ioat_fill_hw_descriptor *hw_desc;
841 	struct ioat_descriptor *desc;
842 	struct ioat_softc *ioat;
843 
844 	CTR0(KTR_IOAT, __func__);
845 	ioat = to_ioat_softc(dmaengine);
846 
847 	if ((ioat->capabilities & IOAT_DMACAP_BFILL) == 0) {
848 		ioat_log_message(0, "%s: Device lacks BFILL capability\n",
849 		    __func__);
850 		return (NULL);
851 	}
852 
853 	if ((dst & (0xffffull << 48)) != 0) {
854 		ioat_log_message(0, "%s: High 16 bits of dst invalid\n",
855 		    __func__);
856 		return (NULL);
857 	}
858 
859 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, fillpattern, dst,
860 	    callback_fn, callback_arg, flags);
861 	if (desc == NULL)
862 		return (NULL);
863 
864 	hw_desc = desc->u.fill;
865 	if (g_ioat_debug_level >= 3)
866 		dump_descriptor(hw_desc);
867 
868 	ioat_submit_single(ioat);
869 	return (&desc->bus_dmadesc);
870 }
871 
872 /*
873  * Ring Management
874  */
875 static inline uint32_t
876 ioat_get_active(struct ioat_softc *ioat)
877 {
878 
879 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
880 }
881 
882 static inline uint32_t
883 ioat_get_ring_space(struct ioat_softc *ioat)
884 {
885 
886 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
887 }
888 
889 static struct ioat_descriptor *
890 ioat_alloc_ring_entry(struct ioat_softc *ioat, int mflags)
891 {
892 	struct ioat_generic_hw_descriptor *hw_desc;
893 	struct ioat_descriptor *desc;
894 	int error, busdmaflag;
895 
896 	error = ENOMEM;
897 	hw_desc = NULL;
898 
899 	if ((mflags & M_WAITOK) != 0)
900 		busdmaflag = BUS_DMA_WAITOK;
901 	else
902 		busdmaflag = BUS_DMA_NOWAIT;
903 
904 	desc = malloc(sizeof(*desc), M_IOAT, mflags);
905 	if (desc == NULL)
906 		goto out;
907 
908 	bus_dmamem_alloc(ioat->hw_desc_tag, (void **)&hw_desc,
909 	    BUS_DMA_ZERO | busdmaflag, &ioat->hw_desc_map);
910 	if (hw_desc == NULL)
911 		goto out;
912 
913 	memset(&desc->bus_dmadesc, 0, sizeof(desc->bus_dmadesc));
914 	desc->u.generic = hw_desc;
915 
916 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
917 	    sizeof(*hw_desc), ioat_dmamap_cb, &desc->hw_desc_bus_addr,
918 	    busdmaflag);
919 	if (error)
920 		goto out;
921 
922 out:
923 	if (error) {
924 		ioat_free_ring_entry(ioat, desc);
925 		return (NULL);
926 	}
927 	return (desc);
928 }
929 
930 static void
931 ioat_free_ring_entry(struct ioat_softc *ioat, struct ioat_descriptor *desc)
932 {
933 
934 	if (desc == NULL)
935 		return;
936 
937 	if (desc->u.generic)
938 		bus_dmamem_free(ioat->hw_desc_tag, desc->u.generic,
939 		    ioat->hw_desc_map);
940 	free(desc, M_IOAT);
941 }
942 
943 /*
944  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
945  * for 'num_descs'.
946  *
947  * If mflags contains M_WAITOK, blocks until enough space is available.
948  *
949  * Returns zero on success, or an errno on error.  If num_descs is beyond the
950  * maximum ring size, returns EINVAl; if allocation would block and mflags
951  * contains M_NOWAIT, returns EAGAIN.
952  *
953  * Must be called with the submit_lock held; returns with the lock held.  The
954  * lock may be dropped to allocate the ring.
955  *
956  * (The submit_lock is needed to add any entries to the ring, so callers are
957  * assured enough room is available.)
958  */
959 static int
960 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
961 {
962 	struct ioat_descriptor **new_ring;
963 	uint32_t order;
964 	int error;
965 
966 	mtx_assert(&ioat->submit_lock, MA_OWNED);
967 	error = 0;
968 
969 	if (num_descs < 1 || num_descs > (1 << IOAT_MAX_ORDER)) {
970 		error = EINVAL;
971 		goto out;
972 	}
973 	if (ioat->quiescing) {
974 		error = ENXIO;
975 		goto out;
976 	}
977 
978 	for (;;) {
979 		if (ioat_get_ring_space(ioat) >= num_descs)
980 			goto out;
981 
982 		order = ioat->ring_size_order;
983 		if (ioat->is_resize_pending || order == IOAT_MAX_ORDER) {
984 			if ((mflags & M_WAITOK) != 0) {
985 				msleep(&ioat->tail, &ioat->submit_lock, 0,
986 				    "ioat_rsz", 0);
987 				continue;
988 			}
989 
990 			error = EAGAIN;
991 			break;
992 		}
993 
994 		ioat->is_resize_pending = TRUE;
995 		for (;;) {
996 			mtx_unlock(&ioat->submit_lock);
997 
998 			new_ring = ioat_prealloc_ring(ioat, 1 << (order + 1),
999 			    TRUE, mflags);
1000 
1001 			mtx_lock(&ioat->submit_lock);
1002 			KASSERT(ioat->ring_size_order == order,
1003 			    ("is_resize_pending should protect order"));
1004 
1005 			if (new_ring == NULL) {
1006 				KASSERT((mflags & M_WAITOK) == 0,
1007 				    ("allocation failed"));
1008 				error = EAGAIN;
1009 				break;
1010 			}
1011 
1012 			error = ring_grow(ioat, order, new_ring);
1013 			if (error == 0)
1014 				break;
1015 		}
1016 		ioat->is_resize_pending = FALSE;
1017 		wakeup(&ioat->tail);
1018 		if (error)
1019 			break;
1020 	}
1021 
1022 out:
1023 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1024 	return (error);
1025 }
1026 
1027 static struct ioat_descriptor **
1028 ioat_prealloc_ring(struct ioat_softc *ioat, uint32_t size, boolean_t need_dscr,
1029     int mflags)
1030 {
1031 	struct ioat_descriptor **ring;
1032 	uint32_t i;
1033 	int error;
1034 
1035 	KASSERT(size > 0 && powerof2(size), ("bogus size"));
1036 
1037 	ring = malloc(size * sizeof(*ring), M_IOAT, M_ZERO | mflags);
1038 	if (ring == NULL)
1039 		return (NULL);
1040 
1041 	if (need_dscr) {
1042 		error = ENOMEM;
1043 		for (i = size / 2; i < size; i++) {
1044 			ring[i] = ioat_alloc_ring_entry(ioat, mflags);
1045 			if (ring[i] == NULL)
1046 				goto out;
1047 			ring[i]->id = i;
1048 		}
1049 	}
1050 	error = 0;
1051 
1052 out:
1053 	if (error != 0 && ring != NULL) {
1054 		ioat_free_ring(ioat, size, ring);
1055 		ring = NULL;
1056 	}
1057 	return (ring);
1058 }
1059 
1060 static void
1061 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1062     struct ioat_descriptor **ring)
1063 {
1064 	uint32_t i;
1065 
1066 	for (i = 0; i < size; i++) {
1067 		if (ring[i] != NULL)
1068 			ioat_free_ring_entry(ioat, ring[i]);
1069 	}
1070 	free(ring, M_IOAT);
1071 }
1072 
1073 static struct ioat_descriptor *
1074 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1075 {
1076 
1077 	return (ioat->ring[index % (1 << ioat->ring_size_order)]);
1078 }
1079 
1080 static int
1081 ring_grow(struct ioat_softc *ioat, uint32_t oldorder,
1082     struct ioat_descriptor **newring)
1083 {
1084 	struct ioat_descriptor *tmp, *next;
1085 	struct ioat_dma_hw_descriptor *hw;
1086 	uint32_t oldsize, newsize, head, tail, i, end;
1087 	int error;
1088 
1089 	CTR0(KTR_IOAT, __func__);
1090 
1091 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1092 
1093 	if (oldorder != ioat->ring_size_order || oldorder >= IOAT_MAX_ORDER) {
1094 		error = EINVAL;
1095 		goto out;
1096 	}
1097 
1098 	oldsize = (1 << oldorder);
1099 	newsize = (1 << (oldorder + 1));
1100 
1101 	mtx_lock(&ioat->cleanup_lock);
1102 
1103 	head = ioat->head & (oldsize - 1);
1104 	tail = ioat->tail & (oldsize - 1);
1105 
1106 	/* Copy old descriptors to new ring */
1107 	for (i = 0; i < oldsize; i++)
1108 		newring[i] = ioat->ring[i];
1109 
1110 	/*
1111 	 * If head has wrapped but tail hasn't, we must swap some descriptors
1112 	 * around so that tail can increment directly to head.
1113 	 */
1114 	if (head < tail) {
1115 		for (i = 0; i <= head; i++) {
1116 			tmp = newring[oldsize + i];
1117 
1118 			newring[oldsize + i] = newring[i];
1119 			newring[oldsize + i]->id = oldsize + i;
1120 
1121 			newring[i] = tmp;
1122 			newring[i]->id = i;
1123 		}
1124 		head += oldsize;
1125 	}
1126 
1127 	KASSERT(head >= tail, ("invariants"));
1128 
1129 	/* Head didn't wrap; we only need to link in oldsize..newsize */
1130 	if (head < oldsize) {
1131 		i = oldsize - 1;
1132 		end = newsize;
1133 	} else {
1134 		/* Head did wrap; link newhead..newsize and 0..oldhead */
1135 		i = head;
1136 		end = newsize + (head - oldsize) + 1;
1137 	}
1138 
1139 	/*
1140 	 * Fix up hardware ring, being careful not to trample the active
1141 	 * section (tail -> head).
1142 	 */
1143 	for (; i < end; i++) {
1144 		KASSERT((i & (newsize - 1)) < tail ||
1145 		    (i & (newsize - 1)) >= head, ("trampling snake"));
1146 
1147 		next = newring[(i + 1) & (newsize - 1)];
1148 		hw = newring[i & (newsize - 1)]->u.dma;
1149 		hw->next = next->hw_desc_bus_addr;
1150 	}
1151 
1152 	free(ioat->ring, M_IOAT);
1153 	ioat->ring = newring;
1154 	ioat->ring_size_order = oldorder + 1;
1155 	ioat->tail = tail;
1156 	ioat->head = head;
1157 	error = 0;
1158 
1159 	mtx_unlock(&ioat->cleanup_lock);
1160 out:
1161 	if (error)
1162 		ioat_free_ring(ioat, (1 << (oldorder + 1)), newring);
1163 	return (error);
1164 }
1165 
1166 static int
1167 ring_shrink(struct ioat_softc *ioat, uint32_t oldorder,
1168     struct ioat_descriptor **newring)
1169 {
1170 	struct ioat_dma_hw_descriptor *hw;
1171 	struct ioat_descriptor *ent, *next;
1172 	uint32_t oldsize, newsize, current_idx, new_idx, i;
1173 	int error;
1174 
1175 	CTR0(KTR_IOAT, __func__);
1176 
1177 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1178 
1179 	if (oldorder != ioat->ring_size_order || oldorder <= IOAT_MIN_ORDER) {
1180 		error = EINVAL;
1181 		goto out_unlocked;
1182 	}
1183 
1184 	oldsize = (1 << oldorder);
1185 	newsize = (1 << (oldorder - 1));
1186 
1187 	mtx_lock(&ioat->cleanup_lock);
1188 
1189 	/* Can't shrink below current active set! */
1190 	if (ioat_get_active(ioat) >= newsize) {
1191 		error = ENOMEM;
1192 		goto out;
1193 	}
1194 
1195 	/*
1196 	 * Copy current descriptors to the new ring, dropping the removed
1197 	 * descriptors.
1198 	 */
1199 	for (i = 0; i < newsize; i++) {
1200 		current_idx = (ioat->tail + i) & (oldsize - 1);
1201 		new_idx = (ioat->tail + i) & (newsize - 1);
1202 
1203 		newring[new_idx] = ioat->ring[current_idx];
1204 		newring[new_idx]->id = new_idx;
1205 	}
1206 
1207 	/* Free deleted descriptors */
1208 	for (i = newsize; i < oldsize; i++) {
1209 		ent = ioat_get_ring_entry(ioat, ioat->tail + i);
1210 		ioat_free_ring_entry(ioat, ent);
1211 	}
1212 
1213 	/* Fix up hardware ring. */
1214 	hw = newring[(ioat->tail + newsize - 1) & (newsize - 1)]->u.dma;
1215 	next = newring[(ioat->tail + newsize) & (newsize - 1)];
1216 	hw->next = next->hw_desc_bus_addr;
1217 
1218 	free(ioat->ring, M_IOAT);
1219 	ioat->ring = newring;
1220 	ioat->ring_size_order = oldorder - 1;
1221 	error = 0;
1222 
1223 out:
1224 	mtx_unlock(&ioat->cleanup_lock);
1225 out_unlocked:
1226 	if (error)
1227 		ioat_free_ring(ioat, (1 << (oldorder - 1)), newring);
1228 	return (error);
1229 }
1230 
1231 static void
1232 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1233 {
1234 	struct ioat_descriptor *desc;
1235 
1236 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1237 	    IOAT_CHANERR_STR);
1238 	if (chanerr == 0)
1239 		return;
1240 
1241 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1242 
1243 	desc = ioat_get_ring_entry(ioat, ioat->tail + 0);
1244 	dump_descriptor(desc->u.raw);
1245 
1246 	desc = ioat_get_ring_entry(ioat, ioat->tail + 1);
1247 	dump_descriptor(desc->u.raw);
1248 }
1249 
1250 static void
1251 ioat_timer_callback(void *arg)
1252 {
1253 	struct ioat_descriptor **newring;
1254 	struct ioat_softc *ioat;
1255 	uint32_t order;
1256 
1257 	ioat = arg;
1258 	ioat_log_message(1, "%s\n", __func__);
1259 
1260 	if (ioat->is_completion_pending) {
1261 		ioat_process_events(ioat);
1262 		return;
1263 	}
1264 
1265 	/* Slowly scale the ring down if idle. */
1266 	mtx_lock(&ioat->submit_lock);
1267 	order = ioat->ring_size_order;
1268 	if (ioat->is_resize_pending || order == IOAT_MIN_ORDER) {
1269 		mtx_unlock(&ioat->submit_lock);
1270 		goto out;
1271 	}
1272 	ioat->is_resize_pending = TRUE;
1273 	mtx_unlock(&ioat->submit_lock);
1274 
1275 	newring = ioat_prealloc_ring(ioat, 1 << (order - 1), FALSE,
1276 	    M_NOWAIT);
1277 
1278 	mtx_lock(&ioat->submit_lock);
1279 	KASSERT(ioat->ring_size_order == order,
1280 	    ("resize_pending protects order"));
1281 
1282 	if (newring != NULL)
1283 		ring_shrink(ioat, order, newring);
1284 
1285 	ioat->is_resize_pending = FALSE;
1286 	mtx_unlock(&ioat->submit_lock);
1287 
1288 out:
1289 	if (ioat->ring_size_order > IOAT_MIN_ORDER)
1290 		callout_reset(&ioat->timer, 10 * hz,
1291 		    ioat_timer_callback, ioat);
1292 }
1293 
1294 /*
1295  * Support Functions
1296  */
1297 static void
1298 ioat_submit_single(struct ioat_softc *ioat)
1299 {
1300 
1301 	ioat_get(ioat, IOAT_ACTIVE_DESCR_REF);
1302 	atomic_add_rel_int(&ioat->head, 1);
1303 	atomic_add_rel_int(&ioat->hw_head, 1);
1304 
1305 	if (!ioat->is_completion_pending) {
1306 		ioat->is_completion_pending = TRUE;
1307 		callout_reset(&ioat->timer, IOAT_INTR_TIMO,
1308 		    ioat_timer_callback, ioat);
1309 	}
1310 }
1311 
1312 static int
1313 ioat_reset_hw(struct ioat_softc *ioat)
1314 {
1315 	uint64_t status;
1316 	uint32_t chanerr;
1317 	unsigned timeout;
1318 	int error;
1319 
1320 	mtx_lock(IOAT_REFLK);
1321 	ioat->quiescing = TRUE;
1322 	ioat_drain_locked(ioat);
1323 	mtx_unlock(IOAT_REFLK);
1324 
1325 	status = ioat_get_chansts(ioat);
1326 	if (is_ioat_active(status) || is_ioat_idle(status))
1327 		ioat_suspend(ioat);
1328 
1329 	/* Wait at most 20 ms */
1330 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1331 	    timeout < 20; timeout++) {
1332 		DELAY(1000);
1333 		status = ioat_get_chansts(ioat);
1334 	}
1335 	if (timeout == 20) {
1336 		error = ETIMEDOUT;
1337 		goto out;
1338 	}
1339 
1340 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1341 
1342 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1343 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1344 
1345 	/*
1346 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1347 	 *  that can cause stability issues for IOAT v3.
1348 	 */
1349 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1350 	    4);
1351 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1352 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1353 
1354 	/*
1355 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1356 	 * Save/restore their contents manually.
1357 	 */
1358 	if (ioat_model_resets_msix(ioat)) {
1359 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1360 		pci_save_state(ioat->device);
1361 	}
1362 
1363 	ioat_reset(ioat);
1364 
1365 	/* Wait at most 20 ms */
1366 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1367 		DELAY(1000);
1368 	if (timeout == 20) {
1369 		error = ETIMEDOUT;
1370 		goto out;
1371 	}
1372 
1373 	if (ioat_model_resets_msix(ioat)) {
1374 		ioat_log_message(1, "device resets registers; restored\n");
1375 		pci_restore_state(ioat->device);
1376 	}
1377 
1378 	/* Reset attempts to return the hardware to "halted." */
1379 	status = ioat_get_chansts(ioat);
1380 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1381 		/* So this really shouldn't happen... */
1382 		ioat_log_message(0, "Device is active after a reset?\n");
1383 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1384 		error = 0;
1385 		goto out;
1386 	}
1387 
1388 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1389 	if (chanerr != 0) {
1390 		mtx_lock(&ioat->cleanup_lock);
1391 		ioat_halted_debug(ioat, chanerr);
1392 		mtx_unlock(&ioat->cleanup_lock);
1393 		error = EIO;
1394 		goto out;
1395 	}
1396 
1397 	/*
1398 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1399 	 * device back to active.
1400 	 *
1401 	 * The internal ring counter resets to zero, so we have to start over
1402 	 * at zero as well.
1403 	 */
1404 	ioat->tail = ioat->head = ioat->hw_head = 0;
1405 	ioat->last_seen = 0;
1406 
1407 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1408 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1409 	ioat_write_chainaddr(ioat, ioat->ring[0]->hw_desc_bus_addr);
1410 	error = 0;
1411 
1412 out:
1413 	mtx_lock(IOAT_REFLK);
1414 	ioat->quiescing = FALSE;
1415 	mtx_unlock(IOAT_REFLK);
1416 
1417 	if (error == 0)
1418 		error = ioat_start_channel(ioat);
1419 
1420 	return (error);
1421 }
1422 
1423 static int
1424 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1425 {
1426 	struct ioat_softc *ioat;
1427 	struct sbuf sb;
1428 	uint64_t status;
1429 	int error;
1430 
1431 	ioat = arg1;
1432 
1433 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1434 
1435 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1436 	switch (status) {
1437 	case IOAT_CHANSTS_ACTIVE:
1438 		sbuf_printf(&sb, "ACTIVE");
1439 		break;
1440 	case IOAT_CHANSTS_IDLE:
1441 		sbuf_printf(&sb, "IDLE");
1442 		break;
1443 	case IOAT_CHANSTS_SUSPENDED:
1444 		sbuf_printf(&sb, "SUSPENDED");
1445 		break;
1446 	case IOAT_CHANSTS_HALTED:
1447 		sbuf_printf(&sb, "HALTED");
1448 		break;
1449 	case IOAT_CHANSTS_ARMED:
1450 		sbuf_printf(&sb, "ARMED");
1451 		break;
1452 	default:
1453 		sbuf_printf(&sb, "UNKNOWN");
1454 		break;
1455 	}
1456 	error = sbuf_finish(&sb);
1457 	sbuf_delete(&sb);
1458 
1459 	if (error != 0 || req->newptr == NULL)
1460 		return (error);
1461 	return (EINVAL);
1462 }
1463 
1464 static int
1465 sysctl_handle_error(SYSCTL_HANDLER_ARGS)
1466 {
1467 	struct ioat_descriptor *desc;
1468 	struct ioat_softc *ioat;
1469 	int error, arg;
1470 
1471 	ioat = arg1;
1472 
1473 	arg = 0;
1474 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1475 	if (error != 0 || req->newptr == NULL)
1476 		return (error);
1477 
1478 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1479 	if (error != 0)
1480 		return (error);
1481 
1482 	if (arg != 0) {
1483 		ioat_acquire(&ioat->dmaengine);
1484 		desc = ioat_op_generic(ioat, IOAT_OP_COPY, 1,
1485 		    0xffff000000000000ull, 0xffff000000000000ull, NULL, NULL,
1486 		    0);
1487 		if (desc == NULL)
1488 			error = ENOMEM;
1489 		else
1490 			ioat_submit_single(ioat);
1491 		ioat_release(&ioat->dmaengine);
1492 	}
1493 	return (error);
1494 }
1495 
1496 static int
1497 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
1498 {
1499 	struct ioat_softc *ioat;
1500 	int error, arg;
1501 
1502 	ioat = arg1;
1503 
1504 	arg = 0;
1505 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1506 	if (error != 0 || req->newptr == NULL)
1507 		return (error);
1508 
1509 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1510 	if (error != 0)
1511 		return (error);
1512 
1513 	if (arg != 0)
1514 		error = ioat_reset_hw(ioat);
1515 
1516 	return (error);
1517 }
1518 
1519 static void
1520 dump_descriptor(void *hw_desc)
1521 {
1522 	int i, j;
1523 
1524 	for (i = 0; i < 2; i++) {
1525 		for (j = 0; j < 8; j++)
1526 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
1527 		printf("\n");
1528 	}
1529 }
1530 
1531 static void
1532 ioat_setup_sysctl(device_t device)
1533 {
1534 	struct sysctl_oid_list *par;
1535 	struct sysctl_ctx_list *ctx;
1536 	struct sysctl_oid *tree;
1537 	struct ioat_softc *ioat;
1538 
1539 	ioat = DEVICE2SOFTC(device);
1540 	ctx = device_get_sysctl_ctx(device);
1541 	tree = device_get_sysctl_tree(device);
1542 	par = SYSCTL_CHILDREN(tree);
1543 
1544 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
1545 	    &ioat->version, 0, "HW version (0xMM form)");
1546 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
1547 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
1548 
1549 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "ring_size_order", CTLFLAG_RD,
1550 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
1551 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "head", CTLFLAG_RD, &ioat->head, 0,
1552 	    "SW descriptor head pointer index");
1553 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail, 0,
1554 	    "SW descriptor tail pointer index");
1555 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "hw_head", CTLFLAG_RD,
1556 	    &ioat->hw_head, 0, "HW DMACOUNT");
1557 
1558 	SYSCTL_ADD_UQUAD(ctx, par, OID_AUTO, "last_completion", CTLFLAG_RD,
1559 	    ioat->comp_update, "HW addr of last completion");
1560 
1561 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_resize_pending", CTLFLAG_RD,
1562 	    &ioat->is_resize_pending, 0, "resize pending");
1563 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_completion_pending", CTLFLAG_RD,
1564 	    &ioat->is_completion_pending, 0, "completion pending");
1565 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_reset_pending", CTLFLAG_RD,
1566 	    &ioat->is_reset_pending, 0, "reset pending");
1567 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_channel_running", CTLFLAG_RD,
1568 	    &ioat->is_channel_running, 0, "channel running");
1569 
1570 	SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "force_hw_reset",
1571 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
1572 	    "Set to non-zero to reset the hardware");
1573 	SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "force_hw_error",
1574 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_error, "I",
1575 	    "Set to non-zero to inject a recoverable hardware error");
1576 	SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "chansts",
1577 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
1578 	    "String of the channel status");
1579 }
1580 
1581 static inline struct ioat_softc *
1582 ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1583 {
1584 	uint32_t old;
1585 
1586 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1587 
1588 	old = atomic_fetchadd_32(&ioat->refcnt, 1);
1589 	KASSERT(old < UINT32_MAX, ("refcnt overflow"));
1590 
1591 #ifdef INVARIANTS
1592 	old = atomic_fetchadd_32(&ioat->refkinds[kind], 1);
1593 	KASSERT(old < UINT32_MAX, ("refcnt kind overflow"));
1594 #endif
1595 
1596 	return (ioat);
1597 }
1598 
1599 static inline void
1600 ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1601 {
1602 
1603 	_ioat_putn(ioat, n, kind, FALSE);
1604 }
1605 
1606 static inline void
1607 ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1608 {
1609 
1610 	_ioat_putn(ioat, n, kind, TRUE);
1611 }
1612 
1613 static inline void
1614 _ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
1615     boolean_t locked)
1616 {
1617 	uint32_t old;
1618 
1619 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1620 
1621 	if (n == 0)
1622 		return;
1623 
1624 #ifdef INVARIANTS
1625 	old = atomic_fetchadd_32(&ioat->refkinds[kind], -n);
1626 	KASSERT(old >= n, ("refcnt kind underflow"));
1627 #endif
1628 
1629 	/* Skip acquiring the lock if resulting refcnt > 0. */
1630 	for (;;) {
1631 		old = ioat->refcnt;
1632 		if (old <= n)
1633 			break;
1634 		if (atomic_cmpset_32(&ioat->refcnt, old, old - n))
1635 			return;
1636 	}
1637 
1638 	if (locked)
1639 		mtx_assert(IOAT_REFLK, MA_OWNED);
1640 	else
1641 		mtx_lock(IOAT_REFLK);
1642 
1643 	old = atomic_fetchadd_32(&ioat->refcnt, -n);
1644 	KASSERT(old >= n, ("refcnt error"));
1645 
1646 	if (old == n)
1647 		wakeup(IOAT_REFLK);
1648 	if (!locked)
1649 		mtx_unlock(IOAT_REFLK);
1650 }
1651 
1652 static inline void
1653 ioat_put(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1654 {
1655 
1656 	ioat_putn(ioat, 1, kind);
1657 }
1658 
1659 static void
1660 ioat_drain_locked(struct ioat_softc *ioat)
1661 {
1662 
1663 	mtx_assert(IOAT_REFLK, MA_OWNED);
1664 	while (ioat->refcnt > 0)
1665 		msleep(IOAT_REFLK, IOAT_REFLK, 0, "ioat_drain", 0);
1666 }
1667