xref: /freebsd/sys/dev/ioat/ioat.c (revision 669f9224ec5398fbc825dd031415126af032cf42)
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 
145 /*
146  * Private data structures
147  */
148 static struct ioat_softc *ioat_channel[IOAT_MAX_CHANNELS];
149 static int ioat_channel_index = 0;
150 SYSCTL_INT(_hw_ioat, OID_AUTO, channels, CTLFLAG_RD, &ioat_channel_index, 0,
151     "Number of IOAT channels attached");
152 
153 static struct _pcsid
154 {
155 	u_int32_t   type;
156 	const char  *desc;
157 } pci_ids[] = {
158 	{ 0x34308086, "TBG IOAT Ch0" },
159 	{ 0x34318086, "TBG IOAT Ch1" },
160 	{ 0x34328086, "TBG IOAT Ch2" },
161 	{ 0x34338086, "TBG IOAT Ch3" },
162 	{ 0x34298086, "TBG IOAT Ch4" },
163 	{ 0x342a8086, "TBG IOAT Ch5" },
164 	{ 0x342b8086, "TBG IOAT Ch6" },
165 	{ 0x342c8086, "TBG IOAT Ch7" },
166 
167 	{ 0x37108086, "JSF IOAT Ch0" },
168 	{ 0x37118086, "JSF IOAT Ch1" },
169 	{ 0x37128086, "JSF IOAT Ch2" },
170 	{ 0x37138086, "JSF IOAT Ch3" },
171 	{ 0x37148086, "JSF IOAT Ch4" },
172 	{ 0x37158086, "JSF IOAT Ch5" },
173 	{ 0x37168086, "JSF IOAT Ch6" },
174 	{ 0x37178086, "JSF IOAT Ch7" },
175 	{ 0x37188086, "JSF IOAT Ch0 (RAID)" },
176 	{ 0x37198086, "JSF IOAT Ch1 (RAID)" },
177 
178 	{ 0x3c208086, "SNB IOAT Ch0" },
179 	{ 0x3c218086, "SNB IOAT Ch1" },
180 	{ 0x3c228086, "SNB IOAT Ch2" },
181 	{ 0x3c238086, "SNB IOAT Ch3" },
182 	{ 0x3c248086, "SNB IOAT Ch4" },
183 	{ 0x3c258086, "SNB IOAT Ch5" },
184 	{ 0x3c268086, "SNB IOAT Ch6" },
185 	{ 0x3c278086, "SNB IOAT Ch7" },
186 	{ 0x3c2e8086, "SNB IOAT Ch0 (RAID)" },
187 	{ 0x3c2f8086, "SNB IOAT Ch1 (RAID)" },
188 
189 	{ 0x0e208086, "IVB IOAT Ch0" },
190 	{ 0x0e218086, "IVB IOAT Ch1" },
191 	{ 0x0e228086, "IVB IOAT Ch2" },
192 	{ 0x0e238086, "IVB IOAT Ch3" },
193 	{ 0x0e248086, "IVB IOAT Ch4" },
194 	{ 0x0e258086, "IVB IOAT Ch5" },
195 	{ 0x0e268086, "IVB IOAT Ch6" },
196 	{ 0x0e278086, "IVB IOAT Ch7" },
197 	{ 0x0e2e8086, "IVB IOAT Ch0 (RAID)" },
198 	{ 0x0e2f8086, "IVB IOAT Ch1 (RAID)" },
199 
200 	{ 0x2f208086, "HSW IOAT Ch0" },
201 	{ 0x2f218086, "HSW IOAT Ch1" },
202 	{ 0x2f228086, "HSW IOAT Ch2" },
203 	{ 0x2f238086, "HSW IOAT Ch3" },
204 	{ 0x2f248086, "HSW IOAT Ch4" },
205 	{ 0x2f258086, "HSW IOAT Ch5" },
206 	{ 0x2f268086, "HSW IOAT Ch6" },
207 	{ 0x2f278086, "HSW IOAT Ch7" },
208 	{ 0x2f2e8086, "HSW IOAT Ch0 (RAID)" },
209 	{ 0x2f2f8086, "HSW IOAT Ch1 (RAID)" },
210 
211 	{ 0x0c508086, "BWD IOAT Ch0" },
212 	{ 0x0c518086, "BWD IOAT Ch1" },
213 	{ 0x0c528086, "BWD IOAT Ch2" },
214 	{ 0x0c538086, "BWD IOAT Ch3" },
215 
216 	{ 0x6f508086, "BDXDE IOAT Ch0" },
217 	{ 0x6f518086, "BDXDE IOAT Ch1" },
218 	{ 0x6f528086, "BDXDE IOAT Ch2" },
219 	{ 0x6f538086, "BDXDE IOAT Ch3" },
220 
221 	{ 0x00000000, NULL           }
222 };
223 
224 /*
225  * OS <-> Driver linkage functions
226  */
227 static int
228 ioat_probe(device_t device)
229 {
230 	struct _pcsid *ep;
231 	u_int32_t type;
232 
233 	type = pci_get_devid(device);
234 	for (ep = pci_ids; ep->type; ep++) {
235 		if (ep->type == type) {
236 			device_set_desc(device, ep->desc);
237 			return (0);
238 		}
239 	}
240 	return (ENXIO);
241 }
242 
243 static int
244 ioat_attach(device_t device)
245 {
246 	struct ioat_softc *ioat;
247 	int error;
248 
249 	ioat = DEVICE2SOFTC(device);
250 	ioat->device = device;
251 
252 	error = ioat_map_pci_bar(ioat);
253 	if (error != 0)
254 		goto err;
255 
256 	ioat->version = ioat_read_cbver(ioat);
257 	if (ioat->version < IOAT_VER_3_0) {
258 		error = ENODEV;
259 		goto err;
260 	}
261 
262 	error = ioat3_attach(device);
263 	if (error != 0)
264 		goto err;
265 
266 	error = pci_enable_busmaster(device);
267 	if (error != 0)
268 		goto err;
269 
270 	error = ioat_setup_intr(ioat);
271 	if (error != 0)
272 		goto err;
273 
274 	error = ioat_reset_hw(ioat);
275 	if (error != 0)
276 		goto err;
277 
278 	ioat_process_events(ioat);
279 	ioat_setup_sysctl(device);
280 
281 	ioat->chan_idx = ioat_channel_index;
282 	ioat_channel[ioat_channel_index++] = ioat;
283 	ioat_test_attach();
284 
285 err:
286 	if (error != 0)
287 		ioat_detach(device);
288 	return (error);
289 }
290 
291 static int
292 ioat_detach(device_t device)
293 {
294 	struct ioat_softc *ioat;
295 
296 	ioat = DEVICE2SOFTC(device);
297 
298 	ioat_test_detach();
299 
300 	mtx_lock(IOAT_REFLK);
301 	ioat->quiescing = TRUE;
302 	ioat_channel[ioat->chan_idx] = NULL;
303 
304 	ioat_drain_locked(ioat);
305 	mtx_unlock(IOAT_REFLK);
306 
307 	ioat_teardown_intr(ioat);
308 	callout_drain(&ioat->timer);
309 
310 	pci_disable_busmaster(device);
311 
312 	if (ioat->pci_resource != NULL)
313 		bus_release_resource(device, SYS_RES_MEMORY,
314 		    ioat->pci_resource_id, ioat->pci_resource);
315 
316 	if (ioat->ring != NULL)
317 		ioat_free_ring(ioat, 1 << ioat->ring_size_order, ioat->ring);
318 
319 	if (ioat->comp_update != NULL) {
320 		bus_dmamap_unload(ioat->comp_update_tag, ioat->comp_update_map);
321 		bus_dmamem_free(ioat->comp_update_tag, ioat->comp_update,
322 		    ioat->comp_update_map);
323 		bus_dma_tag_destroy(ioat->comp_update_tag);
324 	}
325 
326 	bus_dma_tag_destroy(ioat->hw_desc_tag);
327 
328 	return (0);
329 }
330 
331 static int
332 ioat_teardown_intr(struct ioat_softc *ioat)
333 {
334 
335 	if (ioat->tag != NULL)
336 		bus_teardown_intr(ioat->device, ioat->res, ioat->tag);
337 
338 	if (ioat->res != NULL)
339 		bus_release_resource(ioat->device, SYS_RES_IRQ,
340 		    rman_get_rid(ioat->res), ioat->res);
341 
342 	pci_release_msi(ioat->device);
343 	return (0);
344 }
345 
346 static int
347 ioat_start_channel(struct ioat_softc *ioat)
348 {
349 	uint64_t status;
350 	uint32_t chanerr;
351 	int i;
352 
353 	ioat_acquire(&ioat->dmaengine);
354 	ioat_null(&ioat->dmaengine, NULL, NULL, 0);
355 	ioat_release(&ioat->dmaengine);
356 
357 	for (i = 0; i < 100; i++) {
358 		DELAY(1);
359 		status = ioat_get_chansts(ioat);
360 		if (is_ioat_idle(status))
361 			return (0);
362 	}
363 
364 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
365 	ioat_log_message(0, "could not start channel: "
366 	    "status = %#jx error = %b\n", (uintmax_t)status, (int)chanerr,
367 	    IOAT_CHANERR_STR);
368 	return (ENXIO);
369 }
370 
371 /*
372  * Initialize Hardware
373  */
374 static int
375 ioat3_attach(device_t device)
376 {
377 	struct ioat_softc *ioat;
378 	struct ioat_descriptor **ring;
379 	struct ioat_descriptor *next;
380 	struct ioat_dma_hw_descriptor *dma_hw_desc;
381 	int i, num_descriptors;
382 	int error;
383 	uint8_t xfercap;
384 
385 	error = 0;
386 	ioat = DEVICE2SOFTC(device);
387 	ioat->capabilities = ioat_read_dmacapability(ioat);
388 
389 	ioat_log_message(1, "Capabilities: %b\n", (int)ioat->capabilities,
390 	    IOAT_DMACAP_STR);
391 
392 	xfercap = ioat_read_xfercap(ioat);
393 	ioat->max_xfer_size = 1 << xfercap;
394 
395 	/* TODO: need to check DCA here if we ever do XOR/PQ */
396 
397 	mtx_init(&ioat->submit_lock, "ioat_submit", NULL, MTX_DEF);
398 	mtx_init(&ioat->cleanup_lock, "ioat_cleanup", NULL, MTX_DEF);
399 	callout_init(&ioat->timer, 1);
400 
401 	/* Establish lock order for Witness */
402 	mtx_lock(&ioat->submit_lock);
403 	mtx_lock(&ioat->cleanup_lock);
404 	mtx_unlock(&ioat->cleanup_lock);
405 	mtx_unlock(&ioat->submit_lock);
406 
407 	ioat->is_resize_pending = FALSE;
408 	ioat->is_completion_pending = FALSE;
409 	ioat->is_reset_pending = FALSE;
410 	ioat->is_channel_running = FALSE;
411 
412 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), sizeof(uint64_t), 0x0,
413 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
414 	    sizeof(uint64_t), 1, sizeof(uint64_t), 0, NULL, NULL,
415 	    &ioat->comp_update_tag);
416 
417 	error = bus_dmamem_alloc(ioat->comp_update_tag,
418 	    (void **)&ioat->comp_update, BUS_DMA_ZERO, &ioat->comp_update_map);
419 	if (ioat->comp_update == NULL)
420 		return (ENOMEM);
421 
422 	error = bus_dmamap_load(ioat->comp_update_tag, ioat->comp_update_map,
423 	    ioat->comp_update, sizeof(uint64_t), ioat_comp_update_map, ioat,
424 	    0);
425 	if (error != 0)
426 		return (error);
427 
428 	ioat->ring_size_order = IOAT_MIN_ORDER;
429 
430 	num_descriptors = 1 << ioat->ring_size_order;
431 
432 	bus_dma_tag_create(bus_get_dma_tag(ioat->device), 0x40, 0x0,
433 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
434 	    sizeof(struct ioat_dma_hw_descriptor), 1,
435 	    sizeof(struct ioat_dma_hw_descriptor), 0, NULL, NULL,
436 	    &ioat->hw_desc_tag);
437 
438 	ioat->ring = malloc(num_descriptors * sizeof(*ring), M_IOAT,
439 	    M_ZERO | M_WAITOK);
440 	if (ioat->ring == NULL)
441 		return (ENOMEM);
442 
443 	ring = ioat->ring;
444 	for (i = 0; i < num_descriptors; i++) {
445 		ring[i] = ioat_alloc_ring_entry(ioat, M_WAITOK);
446 		if (ring[i] == NULL)
447 			return (ENOMEM);
448 
449 		ring[i]->id = i;
450 	}
451 
452 	for (i = 0; i < num_descriptors - 1; i++) {
453 		next = ring[i + 1];
454 		dma_hw_desc = ring[i]->u.dma;
455 
456 		dma_hw_desc->next = next->hw_desc_bus_addr;
457 	}
458 
459 	ring[i]->u.dma->next = ring[0]->hw_desc_bus_addr;
460 
461 	ioat->head = ioat->hw_head = 0;
462 	ioat->tail = 0;
463 	ioat->last_seen = 0;
464 	return (0);
465 }
466 
467 static int
468 ioat_map_pci_bar(struct ioat_softc *ioat)
469 {
470 
471 	ioat->pci_resource_id = PCIR_BAR(0);
472 	ioat->pci_resource = bus_alloc_resource_any(ioat->device,
473 	    SYS_RES_MEMORY, &ioat->pci_resource_id, RF_ACTIVE);
474 
475 	if (ioat->pci_resource == NULL) {
476 		ioat_log_message(0, "unable to allocate pci resource\n");
477 		return (ENODEV);
478 	}
479 
480 	ioat->pci_bus_tag = rman_get_bustag(ioat->pci_resource);
481 	ioat->pci_bus_handle = rman_get_bushandle(ioat->pci_resource);
482 	return (0);
483 }
484 
485 static void
486 ioat_comp_update_map(void *arg, bus_dma_segment_t *seg, int nseg, int error)
487 {
488 	struct ioat_softc *ioat = arg;
489 
490 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
491 	ioat->comp_update_bus_addr = seg[0].ds_addr;
492 }
493 
494 static void
495 ioat_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
496 {
497 	bus_addr_t *baddr;
498 
499 	KASSERT(error == 0, ("%s: error:%d", __func__, error));
500 	baddr = arg;
501 	*baddr = segs->ds_addr;
502 }
503 
504 /*
505  * Interrupt setup and handlers
506  */
507 static int
508 ioat_setup_intr(struct ioat_softc *ioat)
509 {
510 	uint32_t num_vectors;
511 	int error;
512 	boolean_t use_msix;
513 	boolean_t force_legacy_interrupts;
514 
515 	use_msix = FALSE;
516 	force_legacy_interrupts = FALSE;
517 
518 	if (!g_force_legacy_interrupts && pci_msix_count(ioat->device) >= 1) {
519 		num_vectors = 1;
520 		pci_alloc_msix(ioat->device, &num_vectors);
521 		if (num_vectors == 1)
522 			use_msix = TRUE;
523 	}
524 
525 	if (use_msix) {
526 		ioat->rid = 1;
527 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
528 		    &ioat->rid, RF_ACTIVE);
529 	} else {
530 		ioat->rid = 0;
531 		ioat->res = bus_alloc_resource_any(ioat->device, SYS_RES_IRQ,
532 		    &ioat->rid, RF_SHAREABLE | RF_ACTIVE);
533 	}
534 	if (ioat->res == NULL) {
535 		ioat_log_message(0, "bus_alloc_resource failed\n");
536 		return (ENOMEM);
537 	}
538 
539 	ioat->tag = NULL;
540 	error = bus_setup_intr(ioat->device, ioat->res, INTR_MPSAFE |
541 	    INTR_TYPE_MISC, NULL, ioat_interrupt_handler, ioat, &ioat->tag);
542 	if (error != 0) {
543 		ioat_log_message(0, "bus_setup_intr failed\n");
544 		return (error);
545 	}
546 
547 	ioat_write_intrctrl(ioat, IOAT_INTRCTRL_MASTER_INT_EN);
548 	return (0);
549 }
550 
551 static boolean_t
552 ioat_model_resets_msix(struct ioat_softc *ioat)
553 {
554 	u_int32_t pciid;
555 
556 	pciid = pci_get_devid(ioat->device);
557 	switch (pciid) {
558 		/* BWD: */
559 	case 0x0c508086:
560 	case 0x0c518086:
561 	case 0x0c528086:
562 	case 0x0c538086:
563 		/* BDXDE: */
564 	case 0x6f508086:
565 	case 0x6f518086:
566 	case 0x6f528086:
567 	case 0x6f538086:
568 		return (TRUE);
569 	}
570 
571 	return (FALSE);
572 }
573 
574 static void
575 ioat_interrupt_handler(void *arg)
576 {
577 	struct ioat_softc *ioat = arg;
578 
579 	ioat_process_events(ioat);
580 }
581 
582 static int
583 chanerr_to_errno(uint32_t chanerr)
584 {
585 
586 	if (chanerr == 0)
587 		return (0);
588 	if ((chanerr & (IOAT_CHANERR_XSADDERR | IOAT_CHANERR_XDADDERR)) != 0)
589 		return (EFAULT);
590 	if ((chanerr & (IOAT_CHANERR_RDERR | IOAT_CHANERR_WDERR)) != 0)
591 		return (EIO);
592 	/* This one is probably our fault: */
593 	if ((chanerr & IOAT_CHANERR_NDADDERR) != 0)
594 		return (EIO);
595 	return (EIO);
596 }
597 
598 static void
599 ioat_process_events(struct ioat_softc *ioat)
600 {
601 	struct ioat_descriptor *desc;
602 	struct bus_dmadesc *dmadesc;
603 	uint64_t comp_update, status;
604 	uint32_t completed, chanerr;
605 	int error;
606 
607 	mtx_lock(&ioat->cleanup_lock);
608 
609 	completed = 0;
610 	comp_update = *ioat->comp_update;
611 	status = comp_update & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_MASK;
612 
613 	CTR0(KTR_IOAT, __func__);
614 
615 	if (status == ioat->last_seen)
616 		goto out;
617 
618 	while (1) {
619 		desc = ioat_get_ring_entry(ioat, ioat->tail);
620 		dmadesc = &desc->bus_dmadesc;
621 		CTR1(KTR_IOAT, "completing desc %d", ioat->tail);
622 
623 		if (dmadesc->callback_fn != NULL)
624 			dmadesc->callback_fn(dmadesc->callback_arg, 0);
625 
626 		completed++;
627 		ioat->tail++;
628 		if (desc->hw_desc_bus_addr == status)
629 			break;
630 	}
631 
632 	ioat->last_seen = desc->hw_desc_bus_addr;
633 
634 	if (ioat->head == ioat->tail) {
635 		ioat->is_completion_pending = FALSE;
636 		callout_reset(&ioat->timer, IOAT_INTR_TIMO,
637 		    ioat_timer_callback, ioat);
638 	}
639 
640 out:
641 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
642 	mtx_unlock(&ioat->cleanup_lock);
643 
644 	ioat_putn(ioat, completed, IOAT_ACTIVE_DESCR_REF);
645 	wakeup(&ioat->tail);
646 
647 	if (!is_ioat_halted(comp_update))
648 		return;
649 
650 	/*
651 	 * Fatal programming error on this DMA channel.  Flush any outstanding
652 	 * work with error status and restart the engine.
653 	 */
654 	ioat_log_message(0, "Channel halted due to fatal programming error\n");
655 	mtx_lock(&ioat->submit_lock);
656 	mtx_lock(&ioat->cleanup_lock);
657 	ioat->quiescing = TRUE;
658 
659 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
660 	ioat_halted_debug(ioat, chanerr);
661 
662 	while (ioat_get_active(ioat) > 0) {
663 		desc = ioat_get_ring_entry(ioat, ioat->tail);
664 		dmadesc = &desc->bus_dmadesc;
665 		CTR1(KTR_IOAT, "completing err desc %d", ioat->tail);
666 
667 		if (dmadesc->callback_fn != NULL)
668 			dmadesc->callback_fn(dmadesc->callback_arg,
669 			    chanerr_to_errno(chanerr));
670 
671 		ioat_putn_locked(ioat, 1, IOAT_ACTIVE_DESCR_REF);
672 		ioat->tail++;
673 	}
674 
675 	/* Clear error status */
676 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
677 
678 	mtx_unlock(&ioat->cleanup_lock);
679 	mtx_unlock(&ioat->submit_lock);
680 
681 	ioat_log_message(0, "Resetting channel to recover from error\n");
682 	error = ioat_reset_hw(ioat);
683 	KASSERT(error == 0, ("%s: reset failed: %d", __func__, error));
684 }
685 
686 /*
687  * User API functions
688  */
689 bus_dmaengine_t
690 ioat_get_dmaengine(uint32_t index)
691 {
692 	struct ioat_softc *sc;
693 
694 	if (index >= ioat_channel_index)
695 		return (NULL);
696 
697 	sc = ioat_channel[index];
698 	if (sc == NULL || sc->quiescing)
699 		return (NULL);
700 
701 	return (&ioat_get(sc, IOAT_DMAENGINE_REF)->dmaengine);
702 }
703 
704 void
705 ioat_put_dmaengine(bus_dmaengine_t dmaengine)
706 {
707 	struct ioat_softc *ioat;
708 
709 	ioat = to_ioat_softc(dmaengine);
710 	ioat_put(ioat, IOAT_DMAENGINE_REF);
711 }
712 
713 void
714 ioat_acquire(bus_dmaengine_t dmaengine)
715 {
716 	struct ioat_softc *ioat;
717 
718 	ioat = to_ioat_softc(dmaengine);
719 	mtx_lock(&ioat->submit_lock);
720 	CTR0(KTR_IOAT, __func__);
721 }
722 
723 void
724 ioat_release(bus_dmaengine_t dmaengine)
725 {
726 	struct ioat_softc *ioat;
727 
728 	ioat = to_ioat_softc(dmaengine);
729 	CTR0(KTR_IOAT, __func__);
730 	ioat_write_2(ioat, IOAT_DMACOUNT_OFFSET, (uint16_t)ioat->hw_head);
731 	mtx_unlock(&ioat->submit_lock);
732 }
733 
734 static struct ioat_descriptor *
735 ioat_op_generic(struct ioat_softc *ioat, uint8_t op,
736     uint32_t size, uint64_t src, uint64_t dst,
737     bus_dmaengine_callback_t callback_fn, void *callback_arg,
738     uint32_t flags)
739 {
740 	struct ioat_generic_hw_descriptor *hw_desc;
741 	struct ioat_descriptor *desc;
742 	int mflags;
743 
744 	mtx_assert(&ioat->submit_lock, MA_OWNED);
745 
746 	KASSERT((flags & ~DMA_ALL_FLAGS) == 0, ("Unrecognized flag(s): %#x",
747 		flags & ~DMA_ALL_FLAGS));
748 	if ((flags & DMA_NO_WAIT) != 0)
749 		mflags = M_NOWAIT;
750 	else
751 		mflags = M_WAITOK;
752 
753 	if (size > ioat->max_xfer_size) {
754 		ioat_log_message(0, "%s: max_xfer_size = %d, requested = %u\n",
755 		    __func__, ioat->max_xfer_size, (unsigned)size);
756 		return (NULL);
757 	}
758 
759 	if (ioat_reserve_space(ioat, 1, mflags) != 0)
760 		return (NULL);
761 
762 	desc = ioat_get_ring_entry(ioat, ioat->head);
763 	hw_desc = desc->u.generic;
764 
765 	hw_desc->u.control_raw = 0;
766 	hw_desc->u.control_generic.op = op;
767 	hw_desc->u.control_generic.completion_update = 1;
768 
769 	if ((flags & DMA_INT_EN) != 0)
770 		hw_desc->u.control_generic.int_enable = 1;
771 
772 	hw_desc->size = size;
773 	hw_desc->src_addr = src;
774 	hw_desc->dest_addr = dst;
775 
776 	desc->bus_dmadesc.callback_fn = callback_fn;
777 	desc->bus_dmadesc.callback_arg = callback_arg;
778 	return (desc);
779 }
780 
781 struct bus_dmadesc *
782 ioat_null(bus_dmaengine_t dmaengine, bus_dmaengine_callback_t callback_fn,
783     void *callback_arg, uint32_t flags)
784 {
785 	struct ioat_dma_hw_descriptor *hw_desc;
786 	struct ioat_descriptor *desc;
787 	struct ioat_softc *ioat;
788 
789 	CTR0(KTR_IOAT, __func__);
790 	ioat = to_ioat_softc(dmaengine);
791 
792 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, 8, 0, 0, callback_fn,
793 	    callback_arg, flags);
794 	if (desc == NULL)
795 		return (NULL);
796 
797 	hw_desc = desc->u.dma;
798 	hw_desc->u.control.null = 1;
799 	ioat_submit_single(ioat);
800 	return (&desc->bus_dmadesc);
801 }
802 
803 struct bus_dmadesc *
804 ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
805     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
806     void *callback_arg, uint32_t flags)
807 {
808 	struct ioat_dma_hw_descriptor *hw_desc;
809 	struct ioat_descriptor *desc;
810 	struct ioat_softc *ioat;
811 
812 	CTR0(KTR_IOAT, __func__);
813 	ioat = to_ioat_softc(dmaengine);
814 
815 	if (((src | dst) & (0xffffull << 48)) != 0) {
816 		ioat_log_message(0, "%s: High 16 bits of src/dst invalid\n",
817 		    __func__);
818 		return (NULL);
819 	}
820 
821 	desc = ioat_op_generic(ioat, IOAT_OP_COPY, len, src, dst, callback_fn,
822 	    callback_arg, flags);
823 	if (desc == NULL)
824 		return (NULL);
825 
826 	hw_desc = desc->u.dma;
827 	if (g_ioat_debug_level >= 3)
828 		dump_descriptor(hw_desc);
829 
830 	ioat_submit_single(ioat);
831 	return (&desc->bus_dmadesc);
832 }
833 
834 struct bus_dmadesc *
835 ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst, uint64_t fillpattern,
836     bus_size_t len, bus_dmaengine_callback_t callback_fn, void *callback_arg,
837     uint32_t flags)
838 {
839 	struct ioat_fill_hw_descriptor *hw_desc;
840 	struct ioat_descriptor *desc;
841 	struct ioat_softc *ioat;
842 
843 	CTR0(KTR_IOAT, __func__);
844 	ioat = to_ioat_softc(dmaengine);
845 
846 	if ((ioat->capabilities & IOAT_DMACAP_BFILL) == 0) {
847 		ioat_log_message(0, "%s: Device lacks BFILL capability\n",
848 		    __func__);
849 		return (NULL);
850 	}
851 
852 	if ((dst & (0xffffull << 48)) != 0) {
853 		ioat_log_message(0, "%s: High 16 bits of dst invalid\n",
854 		    __func__);
855 		return (NULL);
856 	}
857 
858 	desc = ioat_op_generic(ioat, IOAT_OP_FILL, len, fillpattern, dst,
859 	    callback_fn, callback_arg, flags);
860 	if (desc == NULL)
861 		return (NULL);
862 
863 	hw_desc = desc->u.fill;
864 	if (g_ioat_debug_level >= 3)
865 		dump_descriptor(hw_desc);
866 
867 	ioat_submit_single(ioat);
868 	return (&desc->bus_dmadesc);
869 }
870 
871 /*
872  * Ring Management
873  */
874 static inline uint32_t
875 ioat_get_active(struct ioat_softc *ioat)
876 {
877 
878 	return ((ioat->head - ioat->tail) & ((1 << ioat->ring_size_order) - 1));
879 }
880 
881 static inline uint32_t
882 ioat_get_ring_space(struct ioat_softc *ioat)
883 {
884 
885 	return ((1 << ioat->ring_size_order) - ioat_get_active(ioat) - 1);
886 }
887 
888 static struct ioat_descriptor *
889 ioat_alloc_ring_entry(struct ioat_softc *ioat, int mflags)
890 {
891 	struct ioat_generic_hw_descriptor *hw_desc;
892 	struct ioat_descriptor *desc;
893 	int error, busdmaflag;
894 
895 	error = ENOMEM;
896 	hw_desc = NULL;
897 
898 	if ((mflags & M_WAITOK) != 0)
899 		busdmaflag = BUS_DMA_WAITOK;
900 	else
901 		busdmaflag = BUS_DMA_NOWAIT;
902 
903 	desc = malloc(sizeof(*desc), M_IOAT, mflags);
904 	if (desc == NULL)
905 		goto out;
906 
907 	bus_dmamem_alloc(ioat->hw_desc_tag, (void **)&hw_desc,
908 	    BUS_DMA_ZERO | busdmaflag, &ioat->hw_desc_map);
909 	if (hw_desc == NULL)
910 		goto out;
911 
912 	memset(&desc->bus_dmadesc, 0, sizeof(desc->bus_dmadesc));
913 	desc->u.generic = hw_desc;
914 
915 	error = bus_dmamap_load(ioat->hw_desc_tag, ioat->hw_desc_map, hw_desc,
916 	    sizeof(*hw_desc), ioat_dmamap_cb, &desc->hw_desc_bus_addr,
917 	    busdmaflag);
918 	if (error)
919 		goto out;
920 
921 out:
922 	if (error) {
923 		ioat_free_ring_entry(ioat, desc);
924 		return (NULL);
925 	}
926 	return (desc);
927 }
928 
929 static void
930 ioat_free_ring_entry(struct ioat_softc *ioat, struct ioat_descriptor *desc)
931 {
932 
933 	if (desc == NULL)
934 		return;
935 
936 	if (desc->u.generic)
937 		bus_dmamem_free(ioat->hw_desc_tag, desc->u.generic,
938 		    ioat->hw_desc_map);
939 	free(desc, M_IOAT);
940 }
941 
942 /*
943  * Reserves space in this IOAT descriptor ring by ensuring enough slots remain
944  * for 'num_descs'.
945  *
946  * If mflags contains M_WAITOK, blocks until enough space is available.
947  *
948  * Returns zero on success, or an errno on error.  If num_descs is beyond the
949  * maximum ring size, returns EINVAl; if allocation would block and mflags
950  * contains M_NOWAIT, returns EAGAIN.
951  *
952  * Must be called with the submit_lock held; returns with the lock held.  The
953  * lock may be dropped to allocate the ring.
954  *
955  * (The submit_lock is needed to add any entries to the ring, so callers are
956  * assured enough room is available.)
957  */
958 static int
959 ioat_reserve_space(struct ioat_softc *ioat, uint32_t num_descs, int mflags)
960 {
961 	struct ioat_descriptor **new_ring;
962 	uint32_t order;
963 	int error;
964 
965 	mtx_assert(&ioat->submit_lock, MA_OWNED);
966 	error = 0;
967 
968 	if (num_descs < 1 || num_descs > (1 << IOAT_MAX_ORDER)) {
969 		error = EINVAL;
970 		goto out;
971 	}
972 	if (ioat->quiescing) {
973 		error = ENXIO;
974 		goto out;
975 	}
976 
977 	for (;;) {
978 		if (ioat_get_ring_space(ioat) >= num_descs)
979 			goto out;
980 
981 		order = ioat->ring_size_order;
982 		if (ioat->is_resize_pending || order == IOAT_MAX_ORDER) {
983 			if ((mflags & M_WAITOK) != 0) {
984 				msleep(&ioat->tail, &ioat->submit_lock, 0,
985 				    "ioat_rsz", 0);
986 				continue;
987 			}
988 
989 			error = EAGAIN;
990 			break;
991 		}
992 
993 		ioat->is_resize_pending = TRUE;
994 		for (;;) {
995 			mtx_unlock(&ioat->submit_lock);
996 
997 			new_ring = ioat_prealloc_ring(ioat, 1 << (order + 1),
998 			    TRUE, mflags);
999 
1000 			mtx_lock(&ioat->submit_lock);
1001 			KASSERT(ioat->ring_size_order == order,
1002 			    ("is_resize_pending should protect order"));
1003 
1004 			if (new_ring == NULL) {
1005 				KASSERT((mflags & M_WAITOK) == 0,
1006 				    ("allocation failed"));
1007 				error = EAGAIN;
1008 				break;
1009 			}
1010 
1011 			error = ring_grow(ioat, order, new_ring);
1012 			if (error == 0)
1013 				break;
1014 		}
1015 		ioat->is_resize_pending = FALSE;
1016 		wakeup(&ioat->tail);
1017 		if (error)
1018 			break;
1019 	}
1020 
1021 out:
1022 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1023 	return (error);
1024 }
1025 
1026 static struct ioat_descriptor **
1027 ioat_prealloc_ring(struct ioat_softc *ioat, uint32_t size, boolean_t need_dscr,
1028     int mflags)
1029 {
1030 	struct ioat_descriptor **ring;
1031 	uint32_t i;
1032 	int error;
1033 
1034 	KASSERT(size > 0 && powerof2(size), ("bogus size"));
1035 
1036 	ring = malloc(size * sizeof(*ring), M_IOAT, M_ZERO | mflags);
1037 	if (ring == NULL)
1038 		return (NULL);
1039 
1040 	if (need_dscr) {
1041 		error = ENOMEM;
1042 		for (i = size / 2; i < size; i++) {
1043 			ring[i] = ioat_alloc_ring_entry(ioat, mflags);
1044 			if (ring[i] == NULL)
1045 				goto out;
1046 			ring[i]->id = i;
1047 		}
1048 	}
1049 	error = 0;
1050 
1051 out:
1052 	if (error != 0 && ring != NULL) {
1053 		ioat_free_ring(ioat, size, ring);
1054 		ring = NULL;
1055 	}
1056 	return (ring);
1057 }
1058 
1059 static void
1060 ioat_free_ring(struct ioat_softc *ioat, uint32_t size,
1061     struct ioat_descriptor **ring)
1062 {
1063 	uint32_t i;
1064 
1065 	for (i = 0; i < size; i++) {
1066 		if (ring[i] != NULL)
1067 			ioat_free_ring_entry(ioat, ring[i]);
1068 	}
1069 	free(ring, M_IOAT);
1070 }
1071 
1072 static struct ioat_descriptor *
1073 ioat_get_ring_entry(struct ioat_softc *ioat, uint32_t index)
1074 {
1075 
1076 	return (ioat->ring[index % (1 << ioat->ring_size_order)]);
1077 }
1078 
1079 static int
1080 ring_grow(struct ioat_softc *ioat, uint32_t oldorder,
1081     struct ioat_descriptor **newring)
1082 {
1083 	struct ioat_descriptor *tmp, *next;
1084 	struct ioat_dma_hw_descriptor *hw;
1085 	uint32_t oldsize, newsize, head, tail, i, end;
1086 	int error;
1087 
1088 	CTR0(KTR_IOAT, __func__);
1089 
1090 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1091 
1092 	if (oldorder != ioat->ring_size_order || oldorder >= IOAT_MAX_ORDER) {
1093 		error = EINVAL;
1094 		goto out;
1095 	}
1096 
1097 	oldsize = (1 << oldorder);
1098 	newsize = (1 << (oldorder + 1));
1099 
1100 	mtx_lock(&ioat->cleanup_lock);
1101 
1102 	head = ioat->head & (oldsize - 1);
1103 	tail = ioat->tail & (oldsize - 1);
1104 
1105 	/* Copy old descriptors to new ring */
1106 	for (i = 0; i < oldsize; i++)
1107 		newring[i] = ioat->ring[i];
1108 
1109 	/*
1110 	 * If head has wrapped but tail hasn't, we must swap some descriptors
1111 	 * around so that tail can increment directly to head.
1112 	 */
1113 	if (head < tail) {
1114 		for (i = 0; i <= head; i++) {
1115 			tmp = newring[oldsize + i];
1116 
1117 			newring[oldsize + i] = newring[i];
1118 			newring[oldsize + i]->id = oldsize + i;
1119 
1120 			newring[i] = tmp;
1121 			newring[i]->id = i;
1122 		}
1123 		head += oldsize;
1124 	}
1125 
1126 	KASSERT(head >= tail, ("invariants"));
1127 
1128 	/* Head didn't wrap; we only need to link in oldsize..newsize */
1129 	if (head < oldsize) {
1130 		i = oldsize - 1;
1131 		end = newsize;
1132 	} else {
1133 		/* Head did wrap; link newhead..newsize and 0..oldhead */
1134 		i = head;
1135 		end = newsize + (head - oldsize) + 1;
1136 	}
1137 
1138 	/*
1139 	 * Fix up hardware ring, being careful not to trample the active
1140 	 * section (tail -> head).
1141 	 */
1142 	for (; i < end; i++) {
1143 		KASSERT((i & (newsize - 1)) < tail ||
1144 		    (i & (newsize - 1)) >= head, ("trampling snake"));
1145 
1146 		next = newring[(i + 1) & (newsize - 1)];
1147 		hw = newring[i & (newsize - 1)]->u.dma;
1148 		hw->next = next->hw_desc_bus_addr;
1149 	}
1150 
1151 	free(ioat->ring, M_IOAT);
1152 	ioat->ring = newring;
1153 	ioat->ring_size_order = oldorder + 1;
1154 	ioat->tail = tail;
1155 	ioat->head = head;
1156 	error = 0;
1157 
1158 	mtx_unlock(&ioat->cleanup_lock);
1159 out:
1160 	if (error)
1161 		ioat_free_ring(ioat, (1 << (oldorder + 1)), newring);
1162 	return (error);
1163 }
1164 
1165 static int
1166 ring_shrink(struct ioat_softc *ioat, uint32_t oldorder,
1167     struct ioat_descriptor **newring)
1168 {
1169 	struct ioat_dma_hw_descriptor *hw;
1170 	struct ioat_descriptor *ent, *next;
1171 	uint32_t oldsize, newsize, current_idx, new_idx, i;
1172 	int error;
1173 
1174 	CTR0(KTR_IOAT, __func__);
1175 
1176 	mtx_assert(&ioat->submit_lock, MA_OWNED);
1177 
1178 	if (oldorder != ioat->ring_size_order || oldorder <= IOAT_MIN_ORDER) {
1179 		error = EINVAL;
1180 		goto out_unlocked;
1181 	}
1182 
1183 	oldsize = (1 << oldorder);
1184 	newsize = (1 << (oldorder - 1));
1185 
1186 	mtx_lock(&ioat->cleanup_lock);
1187 
1188 	/* Can't shrink below current active set! */
1189 	if (ioat_get_active(ioat) >= newsize) {
1190 		error = ENOMEM;
1191 		goto out;
1192 	}
1193 
1194 	/*
1195 	 * Copy current descriptors to the new ring, dropping the removed
1196 	 * descriptors.
1197 	 */
1198 	for (i = 0; i < newsize; i++) {
1199 		current_idx = (ioat->tail + i) & (oldsize - 1);
1200 		new_idx = (ioat->tail + i) & (newsize - 1);
1201 
1202 		newring[new_idx] = ioat->ring[current_idx];
1203 		newring[new_idx]->id = new_idx;
1204 	}
1205 
1206 	/* Free deleted descriptors */
1207 	for (i = newsize; i < oldsize; i++) {
1208 		ent = ioat_get_ring_entry(ioat, ioat->tail + i);
1209 		ioat_free_ring_entry(ioat, ent);
1210 	}
1211 
1212 	/* Fix up hardware ring. */
1213 	hw = newring[(ioat->tail + newsize - 1) & (newsize - 1)]->u.dma;
1214 	next = newring[(ioat->tail + newsize) & (newsize - 1)];
1215 	hw->next = next->hw_desc_bus_addr;
1216 
1217 	free(ioat->ring, M_IOAT);
1218 	ioat->ring = newring;
1219 	ioat->ring_size_order = oldorder - 1;
1220 	error = 0;
1221 
1222 out:
1223 	mtx_unlock(&ioat->cleanup_lock);
1224 out_unlocked:
1225 	if (error)
1226 		ioat_free_ring(ioat, (1 << (oldorder - 1)), newring);
1227 	return (error);
1228 }
1229 
1230 static void
1231 ioat_halted_debug(struct ioat_softc *ioat, uint32_t chanerr)
1232 {
1233 	struct ioat_descriptor *desc;
1234 
1235 	ioat_log_message(0, "Channel halted (%b)\n", (int)chanerr,
1236 	    IOAT_CHANERR_STR);
1237 	if (chanerr == 0)
1238 		return;
1239 
1240 	mtx_assert(&ioat->cleanup_lock, MA_OWNED);
1241 
1242 	desc = ioat_get_ring_entry(ioat, ioat->tail + 0);
1243 	dump_descriptor(desc->u.raw);
1244 
1245 	desc = ioat_get_ring_entry(ioat, ioat->tail + 1);
1246 	dump_descriptor(desc->u.raw);
1247 }
1248 
1249 static void
1250 ioat_timer_callback(void *arg)
1251 {
1252 	struct ioat_descriptor **newring;
1253 	struct ioat_softc *ioat;
1254 	uint32_t order;
1255 
1256 	ioat = arg;
1257 	ioat_log_message(1, "%s\n", __func__);
1258 
1259 	if (ioat->is_completion_pending) {
1260 		ioat_process_events(ioat);
1261 		return;
1262 	}
1263 
1264 	/* Slowly scale the ring down if idle. */
1265 	mtx_lock(&ioat->submit_lock);
1266 	order = ioat->ring_size_order;
1267 	if (ioat->is_resize_pending || order == IOAT_MIN_ORDER) {
1268 		mtx_unlock(&ioat->submit_lock);
1269 		goto out;
1270 	}
1271 	ioat->is_resize_pending = TRUE;
1272 	mtx_unlock(&ioat->submit_lock);
1273 
1274 	newring = ioat_prealloc_ring(ioat, 1 << (order - 1), FALSE,
1275 	    M_NOWAIT);
1276 
1277 	mtx_lock(&ioat->submit_lock);
1278 	KASSERT(ioat->ring_size_order == order,
1279 	    ("resize_pending protects order"));
1280 
1281 	if (newring != NULL)
1282 		ring_shrink(ioat, order, newring);
1283 
1284 	ioat->is_resize_pending = FALSE;
1285 	mtx_unlock(&ioat->submit_lock);
1286 
1287 out:
1288 	if (ioat->ring_size_order > IOAT_MIN_ORDER)
1289 		callout_reset(&ioat->timer, 10 * hz,
1290 		    ioat_timer_callback, ioat);
1291 }
1292 
1293 /*
1294  * Support Functions
1295  */
1296 static void
1297 ioat_submit_single(struct ioat_softc *ioat)
1298 {
1299 
1300 	ioat_get(ioat, IOAT_ACTIVE_DESCR_REF);
1301 	atomic_add_rel_int(&ioat->head, 1);
1302 	atomic_add_rel_int(&ioat->hw_head, 1);
1303 
1304 	if (!ioat->is_completion_pending) {
1305 		ioat->is_completion_pending = TRUE;
1306 		callout_reset(&ioat->timer, IOAT_INTR_TIMO,
1307 		    ioat_timer_callback, ioat);
1308 	}
1309 }
1310 
1311 static int
1312 ioat_reset_hw(struct ioat_softc *ioat)
1313 {
1314 	uint64_t status;
1315 	uint32_t chanerr;
1316 	unsigned timeout;
1317 	int error;
1318 
1319 	mtx_lock(IOAT_REFLK);
1320 	ioat->quiescing = TRUE;
1321 	ioat_drain_locked(ioat);
1322 	mtx_unlock(IOAT_REFLK);
1323 
1324 	status = ioat_get_chansts(ioat);
1325 	if (is_ioat_active(status) || is_ioat_idle(status))
1326 		ioat_suspend(ioat);
1327 
1328 	/* Wait at most 20 ms */
1329 	for (timeout = 0; (is_ioat_active(status) || is_ioat_idle(status)) &&
1330 	    timeout < 20; timeout++) {
1331 		DELAY(1000);
1332 		status = ioat_get_chansts(ioat);
1333 	}
1334 	if (timeout == 20) {
1335 		error = ETIMEDOUT;
1336 		goto out;
1337 	}
1338 
1339 	KASSERT(ioat_get_active(ioat) == 0, ("active after quiesce"));
1340 
1341 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1342 	ioat_write_4(ioat, IOAT_CHANERR_OFFSET, chanerr);
1343 
1344 	/*
1345 	 * IOAT v3 workaround - CHANERRMSK_INT with 3E07h to masks out errors
1346 	 *  that can cause stability issues for IOAT v3.
1347 	 */
1348 	pci_write_config(ioat->device, IOAT_CFG_CHANERRMASK_INT_OFFSET, 0x3e07,
1349 	    4);
1350 	chanerr = pci_read_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, 4);
1351 	pci_write_config(ioat->device, IOAT_CFG_CHANERR_INT_OFFSET, chanerr, 4);
1352 
1353 	/*
1354 	 * BDXDE and BWD models reset MSI-X registers on device reset.
1355 	 * Save/restore their contents manually.
1356 	 */
1357 	if (ioat_model_resets_msix(ioat)) {
1358 		ioat_log_message(1, "device resets MSI-X registers; saving\n");
1359 		pci_save_state(ioat->device);
1360 	}
1361 
1362 	ioat_reset(ioat);
1363 
1364 	/* Wait at most 20 ms */
1365 	for (timeout = 0; ioat_reset_pending(ioat) && timeout < 20; timeout++)
1366 		DELAY(1000);
1367 	if (timeout == 20) {
1368 		error = ETIMEDOUT;
1369 		goto out;
1370 	}
1371 
1372 	if (ioat_model_resets_msix(ioat)) {
1373 		ioat_log_message(1, "device resets registers; restored\n");
1374 		pci_restore_state(ioat->device);
1375 	}
1376 
1377 	/* Reset attempts to return the hardware to "halted." */
1378 	status = ioat_get_chansts(ioat);
1379 	if (is_ioat_active(status) || is_ioat_idle(status)) {
1380 		/* So this really shouldn't happen... */
1381 		ioat_log_message(0, "Device is active after a reset?\n");
1382 		ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1383 		error = 0;
1384 		goto out;
1385 	}
1386 
1387 	chanerr = ioat_read_4(ioat, IOAT_CHANERR_OFFSET);
1388 	if (chanerr != 0) {
1389 		mtx_lock(&ioat->cleanup_lock);
1390 		ioat_halted_debug(ioat, chanerr);
1391 		mtx_unlock(&ioat->cleanup_lock);
1392 		error = EIO;
1393 		goto out;
1394 	}
1395 
1396 	/*
1397 	 * Bring device back online after reset.  Writing CHAINADDR brings the
1398 	 * device back to active.
1399 	 *
1400 	 * The internal ring counter resets to zero, so we have to start over
1401 	 * at zero as well.
1402 	 */
1403 	ioat->tail = ioat->head = ioat->hw_head = 0;
1404 	ioat->last_seen = 0;
1405 
1406 	ioat_write_chanctrl(ioat, IOAT_CHANCTRL_RUN);
1407 	ioat_write_chancmp(ioat, ioat->comp_update_bus_addr);
1408 	ioat_write_chainaddr(ioat, ioat->ring[0]->hw_desc_bus_addr);
1409 	error = 0;
1410 
1411 out:
1412 	mtx_lock(IOAT_REFLK);
1413 	ioat->quiescing = FALSE;
1414 	mtx_unlock(IOAT_REFLK);
1415 
1416 	if (error == 0)
1417 		error = ioat_start_channel(ioat);
1418 
1419 	return (error);
1420 }
1421 
1422 static int
1423 sysctl_handle_chansts(SYSCTL_HANDLER_ARGS)
1424 {
1425 	struct ioat_softc *ioat;
1426 	struct sbuf sb;
1427 	uint64_t status;
1428 	int error;
1429 
1430 	ioat = arg1;
1431 
1432 	status = ioat_get_chansts(ioat) & IOAT_CHANSTS_STATUS;
1433 
1434 	sbuf_new_for_sysctl(&sb, NULL, 256, req);
1435 	switch (status) {
1436 	case IOAT_CHANSTS_ACTIVE:
1437 		sbuf_printf(&sb, "ACTIVE");
1438 		break;
1439 	case IOAT_CHANSTS_IDLE:
1440 		sbuf_printf(&sb, "IDLE");
1441 		break;
1442 	case IOAT_CHANSTS_SUSPENDED:
1443 		sbuf_printf(&sb, "SUSPENDED");
1444 		break;
1445 	case IOAT_CHANSTS_HALTED:
1446 		sbuf_printf(&sb, "HALTED");
1447 		break;
1448 	case IOAT_CHANSTS_ARMED:
1449 		sbuf_printf(&sb, "ARMED");
1450 		break;
1451 	default:
1452 		sbuf_printf(&sb, "UNKNOWN");
1453 		break;
1454 	}
1455 	error = sbuf_finish(&sb);
1456 	sbuf_delete(&sb);
1457 
1458 	if (error != 0 || req->newptr == NULL)
1459 		return (error);
1460 	return (EINVAL);
1461 }
1462 
1463 static int
1464 sysctl_handle_error(SYSCTL_HANDLER_ARGS)
1465 {
1466 	struct ioat_descriptor *desc;
1467 	struct ioat_softc *ioat;
1468 	int error, arg;
1469 
1470 	ioat = arg1;
1471 
1472 	arg = 0;
1473 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1474 	if (error != 0 || req->newptr == NULL)
1475 		return (error);
1476 
1477 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1478 	if (error != 0)
1479 		return (error);
1480 
1481 	if (arg != 0) {
1482 		ioat_acquire(&ioat->dmaengine);
1483 		desc = ioat_op_generic(ioat, IOAT_OP_COPY, 1,
1484 		    0xffff000000000000ull, 0xffff000000000000ull, NULL, NULL,
1485 		    0);
1486 		if (desc == NULL)
1487 			error = ENOMEM;
1488 		else
1489 			ioat_submit_single(ioat);
1490 		ioat_release(&ioat->dmaengine);
1491 	}
1492 	return (error);
1493 }
1494 
1495 static int
1496 sysctl_handle_reset(SYSCTL_HANDLER_ARGS)
1497 {
1498 	struct ioat_softc *ioat;
1499 	int error, arg;
1500 
1501 	ioat = arg1;
1502 
1503 	arg = 0;
1504 	error = SYSCTL_OUT(req, &arg, sizeof(arg));
1505 	if (error != 0 || req->newptr == NULL)
1506 		return (error);
1507 
1508 	error = SYSCTL_IN(req, &arg, sizeof(arg));
1509 	if (error != 0)
1510 		return (error);
1511 
1512 	if (arg != 0)
1513 		error = ioat_reset_hw(ioat);
1514 
1515 	return (error);
1516 }
1517 
1518 static void
1519 dump_descriptor(void *hw_desc)
1520 {
1521 	int i, j;
1522 
1523 	for (i = 0; i < 2; i++) {
1524 		for (j = 0; j < 8; j++)
1525 			printf("%08x ", ((uint32_t *)hw_desc)[i * 8 + j]);
1526 		printf("\n");
1527 	}
1528 }
1529 
1530 static void
1531 ioat_setup_sysctl(device_t device)
1532 {
1533 	struct sysctl_oid_list *par;
1534 	struct sysctl_ctx_list *ctx;
1535 	struct sysctl_oid *tree;
1536 	struct ioat_softc *ioat;
1537 
1538 	ioat = DEVICE2SOFTC(device);
1539 	ctx = device_get_sysctl_ctx(device);
1540 	tree = device_get_sysctl_tree(device);
1541 	par = SYSCTL_CHILDREN(tree);
1542 
1543 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "version", CTLFLAG_RD,
1544 	    &ioat->version, 0, "HW version (0xMM form)");
1545 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "max_xfer_size", CTLFLAG_RD,
1546 	    &ioat->max_xfer_size, 0, "HW maximum transfer size");
1547 
1548 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "ring_size_order", CTLFLAG_RD,
1549 	    &ioat->ring_size_order, 0, "SW descriptor ring size order");
1550 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "head", CTLFLAG_RD, &ioat->head, 0,
1551 	    "SW descriptor head pointer index");
1552 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "tail", CTLFLAG_RD, &ioat->tail, 0,
1553 	    "SW descriptor tail pointer index");
1554 	SYSCTL_ADD_UINT(ctx, par, OID_AUTO, "hw_head", CTLFLAG_RD,
1555 	    &ioat->hw_head, 0, "HW DMACOUNT");
1556 
1557 	SYSCTL_ADD_UQUAD(ctx, par, OID_AUTO, "last_completion", CTLFLAG_RD,
1558 	    ioat->comp_update, "HW addr of last completion");
1559 
1560 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_resize_pending", CTLFLAG_RD,
1561 	    &ioat->is_resize_pending, 0, "resize pending");
1562 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_completion_pending", CTLFLAG_RD,
1563 	    &ioat->is_completion_pending, 0, "completion pending");
1564 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_reset_pending", CTLFLAG_RD,
1565 	    &ioat->is_reset_pending, 0, "reset pending");
1566 	SYSCTL_ADD_INT(ctx, par, OID_AUTO, "is_channel_running", CTLFLAG_RD,
1567 	    &ioat->is_channel_running, 0, "channel running");
1568 
1569 	SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "force_hw_reset",
1570 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_reset, "I",
1571 	    "Set to non-zero to reset the hardware");
1572 	SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "force_hw_error",
1573 	    CTLTYPE_INT | CTLFLAG_RW, ioat, 0, sysctl_handle_error, "I",
1574 	    "Set to non-zero to inject a recoverable hardware error");
1575 	SYSCTL_ADD_PROC(ctx, par, OID_AUTO, "chansts",
1576 	    CTLTYPE_STRING | CTLFLAG_RD, ioat, 0, sysctl_handle_chansts, "A",
1577 	    "String of the channel status");
1578 }
1579 
1580 static inline struct ioat_softc *
1581 ioat_get(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1582 {
1583 	uint32_t old;
1584 
1585 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1586 
1587 	old = atomic_fetchadd_32(&ioat->refcnt, 1);
1588 	KASSERT(old < UINT32_MAX, ("refcnt overflow"));
1589 
1590 #ifdef INVARIANTS
1591 	old = atomic_fetchadd_32(&ioat->refkinds[kind], 1);
1592 	KASSERT(old < UINT32_MAX, ("refcnt kind overflow"));
1593 #endif
1594 
1595 	return (ioat);
1596 }
1597 
1598 static inline void
1599 ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1600 {
1601 
1602 	_ioat_putn(ioat, n, kind, FALSE);
1603 }
1604 
1605 static inline void
1606 ioat_putn_locked(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind)
1607 {
1608 
1609 	_ioat_putn(ioat, n, kind, TRUE);
1610 }
1611 
1612 static inline void
1613 _ioat_putn(struct ioat_softc *ioat, uint32_t n, enum ioat_ref_kind kind,
1614     boolean_t locked)
1615 {
1616 	uint32_t old;
1617 
1618 	KASSERT(kind < IOAT_NUM_REF_KINDS, ("bogus"));
1619 
1620 	if (n == 0)
1621 		return;
1622 
1623 #ifdef INVARIANTS
1624 	old = atomic_fetchadd_32(&ioat->refkinds[kind], -n);
1625 	KASSERT(old >= n, ("refcnt kind underflow"));
1626 #endif
1627 
1628 	/* Skip acquiring the lock if resulting refcnt > 0. */
1629 	for (;;) {
1630 		old = ioat->refcnt;
1631 		if (old <= n)
1632 			break;
1633 		if (atomic_cmpset_32(&ioat->refcnt, old, old - n))
1634 			return;
1635 	}
1636 
1637 	if (locked)
1638 		mtx_assert(IOAT_REFLK, MA_OWNED);
1639 	else
1640 		mtx_lock(IOAT_REFLK);
1641 
1642 	old = atomic_fetchadd_32(&ioat->refcnt, -n);
1643 	KASSERT(old >= n, ("refcnt error"));
1644 
1645 	if (old == n)
1646 		wakeup(IOAT_REFLK);
1647 	if (!locked)
1648 		mtx_unlock(IOAT_REFLK);
1649 }
1650 
1651 static inline void
1652 ioat_put(struct ioat_softc *ioat, enum ioat_ref_kind kind)
1653 {
1654 
1655 	ioat_putn(ioat, 1, kind);
1656 }
1657 
1658 static void
1659 ioat_drain_locked(struct ioat_softc *ioat)
1660 {
1661 
1662 	mtx_assert(IOAT_REFLK, MA_OWNED);
1663 	while (ioat->refcnt > 0)
1664 		msleep(IOAT_REFLK, IOAT_REFLK, 0, "ioat_drain", 0);
1665 }
1666