xref: /openbmc/linux/drivers/ntb/hw/intel/ntb_hw_gen3.c (revision 6d99a79c)
1 /*
2  * This file is provided under a dual BSD/GPLv2 license.  When using or
3  *   redistributing this file, you may do so under either license.
4  *
5  *   GPL LICENSE SUMMARY
6  *
7  *   Copyright(c) 2017 Intel Corporation. All rights reserved.
8  *
9  *   This program is free software; you can redistribute it and/or modify
10  *   it under the terms of version 2 of the GNU General Public License as
11  *   published by the Free Software Foundation.
12  *
13  *   BSD LICENSE
14  *
15  *   Copyright(c) 2017 Intel Corporation. All rights reserved.
16  *
17  *   Redistribution and use in source and binary forms, with or without
18  *   modification, are permitted provided that the following conditions
19  *   are met:
20  *
21  *     * Redistributions of source code must retain the above copyright
22  *       notice, this list of conditions and the following disclaimer.
23  *     * Redistributions in binary form must reproduce the above copy
24  *       notice, this list of conditions and the following disclaimer in
25  *       the documentation and/or other materials provided with the
26  *       distribution.
27  *     * Neither the name of Intel Corporation nor the names of its
28  *       contributors may be used to endorse or promote products derived
29  *       from this software without specific prior written permission.
30  *
31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42  *
43  * Intel PCIe GEN3 NTB Linux driver
44  *
45  */
46 
47 #include <linux/debugfs.h>
48 #include <linux/delay.h>
49 #include <linux/init.h>
50 #include <linux/interrupt.h>
51 #include <linux/module.h>
52 #include <linux/pci.h>
53 #include <linux/random.h>
54 #include <linux/slab.h>
55 #include <linux/ntb.h>
56 
57 #include "ntb_hw_intel.h"
58 #include "ntb_hw_gen1.h"
59 #include "ntb_hw_gen3.h"
60 
61 static int gen3_poll_link(struct intel_ntb_dev *ndev);
62 
63 static const struct intel_ntb_reg gen3_reg = {
64 	.poll_link		= gen3_poll_link,
65 	.link_is_up		= xeon_link_is_up,
66 	.db_ioread		= gen3_db_ioread,
67 	.db_iowrite		= gen3_db_iowrite,
68 	.db_size		= sizeof(u32),
69 	.ntb_ctl		= GEN3_NTBCNTL_OFFSET,
70 	.mw_bar			= {2, 4},
71 };
72 
73 static const struct intel_ntb_alt_reg gen3_pri_reg = {
74 	.db_bell		= GEN3_EM_DOORBELL_OFFSET,
75 	.db_clear		= GEN3_IM_INT_STATUS_OFFSET,
76 	.db_mask		= GEN3_IM_INT_DISABLE_OFFSET,
77 	.spad			= GEN3_IM_SPAD_OFFSET,
78 };
79 
80 static const struct intel_ntb_alt_reg gen3_b2b_reg = {
81 	.db_bell		= GEN3_IM_DOORBELL_OFFSET,
82 	.db_clear		= GEN3_EM_INT_STATUS_OFFSET,
83 	.db_mask		= GEN3_EM_INT_DISABLE_OFFSET,
84 	.spad			= GEN3_B2B_SPAD_OFFSET,
85 };
86 
87 static const struct intel_ntb_xlat_reg gen3_sec_xlat = {
88 /*	.bar0_base		= GEN3_EMBAR0_OFFSET, */
89 	.bar2_limit		= GEN3_IMBAR1XLMT_OFFSET,
90 	.bar2_xlat		= GEN3_IMBAR1XBASE_OFFSET,
91 };
92 
93 static int gen3_poll_link(struct intel_ntb_dev *ndev)
94 {
95 	u16 reg_val;
96 	int rc;
97 
98 	ndev->reg->db_iowrite(ndev->db_link_mask,
99 			      ndev->self_mmio +
100 			      ndev->self_reg->db_clear);
101 
102 	rc = pci_read_config_word(ndev->ntb.pdev,
103 				  GEN3_LINK_STATUS_OFFSET, &reg_val);
104 	if (rc)
105 		return 0;
106 
107 	if (reg_val == ndev->lnk_sta)
108 		return 0;
109 
110 	ndev->lnk_sta = reg_val;
111 
112 	return 1;
113 }
114 
115 static int gen3_init_isr(struct intel_ntb_dev *ndev)
116 {
117 	int i;
118 
119 	/*
120 	 * The MSIX vectors and the interrupt status bits are not lined up
121 	 * on Skylake. By default the link status bit is bit 32, however it
122 	 * is by default MSIX vector0. We need to fixup to line them up.
123 	 * The vectors at reset is 1-32,0. We need to reprogram to 0-32.
124 	 */
125 
126 	for (i = 0; i < GEN3_DB_MSIX_VECTOR_COUNT; i++)
127 		iowrite8(i, ndev->self_mmio + GEN3_INTVEC_OFFSET + i);
128 
129 	/* move link status down one as workaround */
130 	if (ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD) {
131 		iowrite8(GEN3_DB_MSIX_VECTOR_COUNT - 2,
132 			 ndev->self_mmio + GEN3_INTVEC_OFFSET +
133 			 (GEN3_DB_MSIX_VECTOR_COUNT - 1));
134 	}
135 
136 	return ndev_init_isr(ndev, GEN3_DB_MSIX_VECTOR_COUNT,
137 			     GEN3_DB_MSIX_VECTOR_COUNT,
138 			     GEN3_DB_MSIX_VECTOR_SHIFT,
139 			     GEN3_DB_TOTAL_SHIFT);
140 }
141 
142 static int gen3_setup_b2b_mw(struct intel_ntb_dev *ndev,
143 			    const struct intel_b2b_addr *addr,
144 			    const struct intel_b2b_addr *peer_addr)
145 {
146 	struct pci_dev *pdev;
147 	void __iomem *mmio;
148 	phys_addr_t bar_addr;
149 
150 	pdev = ndev->ntb.pdev;
151 	mmio = ndev->self_mmio;
152 
153 	/* setup incoming bar limits == base addrs (zero length windows) */
154 	bar_addr = addr->bar2_addr64;
155 	iowrite64(bar_addr, mmio + GEN3_IMBAR1XLMT_OFFSET);
156 	bar_addr = ioread64(mmio + GEN3_IMBAR1XLMT_OFFSET);
157 	dev_dbg(&pdev->dev, "IMBAR1XLMT %#018llx\n", bar_addr);
158 
159 	bar_addr = addr->bar4_addr64;
160 	iowrite64(bar_addr, mmio + GEN3_IMBAR2XLMT_OFFSET);
161 	bar_addr = ioread64(mmio + GEN3_IMBAR2XLMT_OFFSET);
162 	dev_dbg(&pdev->dev, "IMBAR2XLMT %#018llx\n", bar_addr);
163 
164 	/* zero incoming translation addrs */
165 	iowrite64(0, mmio + GEN3_IMBAR1XBASE_OFFSET);
166 	iowrite64(0, mmio + GEN3_IMBAR2XBASE_OFFSET);
167 
168 	ndev->peer_mmio = ndev->self_mmio;
169 
170 	return 0;
171 }
172 
173 static int gen3_init_ntb(struct intel_ntb_dev *ndev)
174 {
175 	int rc;
176 
177 
178 	ndev->mw_count = XEON_MW_COUNT;
179 	ndev->spad_count = GEN3_SPAD_COUNT;
180 	ndev->db_count = GEN3_DB_COUNT;
181 	ndev->db_link_mask = GEN3_DB_LINK_BIT;
182 
183 	/* DB fixup for using 31 right now */
184 	if (ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD)
185 		ndev->db_link_mask |= BIT_ULL(31);
186 
187 	switch (ndev->ntb.topo) {
188 	case NTB_TOPO_B2B_USD:
189 	case NTB_TOPO_B2B_DSD:
190 		ndev->self_reg = &gen3_pri_reg;
191 		ndev->peer_reg = &gen3_b2b_reg;
192 		ndev->xlat_reg = &gen3_sec_xlat;
193 
194 		if (ndev->ntb.topo == NTB_TOPO_B2B_USD) {
195 			rc = gen3_setup_b2b_mw(ndev,
196 					      &xeon_b2b_dsd_addr,
197 					      &xeon_b2b_usd_addr);
198 		} else {
199 			rc = gen3_setup_b2b_mw(ndev,
200 					      &xeon_b2b_usd_addr,
201 					      &xeon_b2b_dsd_addr);
202 		}
203 
204 		if (rc)
205 			return rc;
206 
207 		/* Enable Bus Master and Memory Space on the secondary side */
208 		iowrite16(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
209 			  ndev->self_mmio + GEN3_SPCICMD_OFFSET);
210 
211 		break;
212 
213 	default:
214 		return -EINVAL;
215 	}
216 
217 	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
218 
219 	ndev->reg->db_iowrite(ndev->db_valid_mask,
220 			      ndev->self_mmio +
221 			      ndev->self_reg->db_mask);
222 
223 	return 0;
224 }
225 
226 int gen3_init_dev(struct intel_ntb_dev *ndev)
227 {
228 	struct pci_dev *pdev;
229 	u8 ppd;
230 	int rc;
231 
232 	pdev = ndev->ntb.pdev;
233 
234 	ndev->reg = &gen3_reg;
235 
236 	rc = pci_read_config_byte(pdev, XEON_PPD_OFFSET, &ppd);
237 	if (rc)
238 		return -EIO;
239 
240 	ndev->ntb.topo = xeon_ppd_topo(ndev, ppd);
241 	dev_dbg(&pdev->dev, "ppd %#x topo %s\n", ppd,
242 		ntb_topo_string(ndev->ntb.topo));
243 	if (ndev->ntb.topo == NTB_TOPO_NONE)
244 		return -EINVAL;
245 
246 	ndev->hwerr_flags |= NTB_HWERR_MSIX_VECTOR32_BAD;
247 
248 	rc = gen3_init_ntb(ndev);
249 	if (rc)
250 		return rc;
251 
252 	return gen3_init_isr(ndev);
253 }
254 
255 ssize_t ndev_ntb3_debugfs_read(struct file *filp, char __user *ubuf,
256 				      size_t count, loff_t *offp)
257 {
258 	struct intel_ntb_dev *ndev;
259 	void __iomem *mmio;
260 	char *buf;
261 	size_t buf_size;
262 	ssize_t ret, off;
263 	union { u64 v64; u32 v32; u16 v16; } u;
264 
265 	ndev = filp->private_data;
266 	mmio = ndev->self_mmio;
267 
268 	buf_size = min(count, 0x800ul);
269 
270 	buf = kmalloc(buf_size, GFP_KERNEL);
271 	if (!buf)
272 		return -ENOMEM;
273 
274 	off = 0;
275 
276 	off += scnprintf(buf + off, buf_size - off,
277 			 "NTB Device Information:\n");
278 
279 	off += scnprintf(buf + off, buf_size - off,
280 			 "Connection Topology -\t%s\n",
281 			 ntb_topo_string(ndev->ntb.topo));
282 
283 	off += scnprintf(buf + off, buf_size - off,
284 			 "NTB CTL -\t\t%#06x\n", ndev->ntb_ctl);
285 	off += scnprintf(buf + off, buf_size - off,
286 			 "LNK STA -\t\t%#06x\n", ndev->lnk_sta);
287 
288 	if (!ndev->reg->link_is_up(ndev))
289 		off += scnprintf(buf + off, buf_size - off,
290 				 "Link Status -\t\tDown\n");
291 	else {
292 		off += scnprintf(buf + off, buf_size - off,
293 				 "Link Status -\t\tUp\n");
294 		off += scnprintf(buf + off, buf_size - off,
295 				 "Link Speed -\t\tPCI-E Gen %u\n",
296 				 NTB_LNK_STA_SPEED(ndev->lnk_sta));
297 		off += scnprintf(buf + off, buf_size - off,
298 				 "Link Width -\t\tx%u\n",
299 				 NTB_LNK_STA_WIDTH(ndev->lnk_sta));
300 	}
301 
302 	off += scnprintf(buf + off, buf_size - off,
303 			 "Memory Window Count -\t%u\n", ndev->mw_count);
304 	off += scnprintf(buf + off, buf_size - off,
305 			 "Scratchpad Count -\t%u\n", ndev->spad_count);
306 	off += scnprintf(buf + off, buf_size - off,
307 			 "Doorbell Count -\t%u\n", ndev->db_count);
308 	off += scnprintf(buf + off, buf_size - off,
309 			 "Doorbell Vector Count -\t%u\n", ndev->db_vec_count);
310 	off += scnprintf(buf + off, buf_size - off,
311 			 "Doorbell Vector Shift -\t%u\n", ndev->db_vec_shift);
312 
313 	off += scnprintf(buf + off, buf_size - off,
314 			 "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
315 	off += scnprintf(buf + off, buf_size - off,
316 			 "Doorbell Link Mask -\t%#llx\n", ndev->db_link_mask);
317 	off += scnprintf(buf + off, buf_size - off,
318 			 "Doorbell Mask Cached -\t%#llx\n", ndev->db_mask);
319 
320 	u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_mask);
321 	off += scnprintf(buf + off, buf_size - off,
322 			 "Doorbell Mask -\t\t%#llx\n", u.v64);
323 
324 	u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_bell);
325 	off += scnprintf(buf + off, buf_size - off,
326 			 "Doorbell Bell -\t\t%#llx\n", u.v64);
327 
328 	off += scnprintf(buf + off, buf_size - off,
329 			 "\nNTB Incoming XLAT:\n");
330 
331 	u.v64 = ioread64(mmio + GEN3_IMBAR1XBASE_OFFSET);
332 	off += scnprintf(buf + off, buf_size - off,
333 			 "IMBAR1XBASE -\t\t%#018llx\n", u.v64);
334 
335 	u.v64 = ioread64(mmio + GEN3_IMBAR2XBASE_OFFSET);
336 	off += scnprintf(buf + off, buf_size - off,
337 			 "IMBAR2XBASE -\t\t%#018llx\n", u.v64);
338 
339 	u.v64 = ioread64(mmio + GEN3_IMBAR1XLMT_OFFSET);
340 	off += scnprintf(buf + off, buf_size - off,
341 			 "IMBAR1XLMT -\t\t\t%#018llx\n", u.v64);
342 
343 	u.v64 = ioread64(mmio + GEN3_IMBAR2XLMT_OFFSET);
344 	off += scnprintf(buf + off, buf_size - off,
345 			 "IMBAR2XLMT -\t\t\t%#018llx\n", u.v64);
346 
347 	if (ntb_topo_is_b2b(ndev->ntb.topo)) {
348 		off += scnprintf(buf + off, buf_size - off,
349 				 "\nNTB Outgoing B2B XLAT:\n");
350 
351 		u.v64 = ioread64(mmio + GEN3_EMBAR1XBASE_OFFSET);
352 		off += scnprintf(buf + off, buf_size - off,
353 				 "EMBAR1XBASE -\t\t%#018llx\n", u.v64);
354 
355 		u.v64 = ioread64(mmio + GEN3_EMBAR2XBASE_OFFSET);
356 		off += scnprintf(buf + off, buf_size - off,
357 				 "EMBAR2XBASE -\t\t%#018llx\n", u.v64);
358 
359 		u.v64 = ioread64(mmio + GEN3_EMBAR1XLMT_OFFSET);
360 		off += scnprintf(buf + off, buf_size - off,
361 				 "EMBAR1XLMT -\t\t%#018llx\n", u.v64);
362 
363 		u.v64 = ioread64(mmio + GEN3_EMBAR2XLMT_OFFSET);
364 		off += scnprintf(buf + off, buf_size - off,
365 				 "EMBAR2XLMT -\t\t%#018llx\n", u.v64);
366 
367 		off += scnprintf(buf + off, buf_size - off,
368 				 "\nNTB Secondary BAR:\n");
369 
370 		u.v64 = ioread64(mmio + GEN3_EMBAR0_OFFSET);
371 		off += scnprintf(buf + off, buf_size - off,
372 				 "EMBAR0 -\t\t%#018llx\n", u.v64);
373 
374 		u.v64 = ioread64(mmio + GEN3_EMBAR1_OFFSET);
375 		off += scnprintf(buf + off, buf_size - off,
376 				 "EMBAR1 -\t\t%#018llx\n", u.v64);
377 
378 		u.v64 = ioread64(mmio + GEN3_EMBAR2_OFFSET);
379 		off += scnprintf(buf + off, buf_size - off,
380 				 "EMBAR2 -\t\t%#018llx\n", u.v64);
381 	}
382 
383 	off += scnprintf(buf + off, buf_size - off,
384 			 "\nNTB Statistics:\n");
385 
386 	u.v16 = ioread16(mmio + GEN3_USMEMMISS_OFFSET);
387 	off += scnprintf(buf + off, buf_size - off,
388 			 "Upstream Memory Miss -\t%u\n", u.v16);
389 
390 	off += scnprintf(buf + off, buf_size - off,
391 			 "\nNTB Hardware Errors:\n");
392 
393 	if (!pci_read_config_word(ndev->ntb.pdev,
394 				  GEN3_DEVSTS_OFFSET, &u.v16))
395 		off += scnprintf(buf + off, buf_size - off,
396 				 "DEVSTS -\t\t%#06x\n", u.v16);
397 
398 	if (!pci_read_config_word(ndev->ntb.pdev,
399 				  GEN3_LINK_STATUS_OFFSET, &u.v16))
400 		off += scnprintf(buf + off, buf_size - off,
401 				 "LNKSTS -\t\t%#06x\n", u.v16);
402 
403 	if (!pci_read_config_dword(ndev->ntb.pdev,
404 				   GEN3_UNCERRSTS_OFFSET, &u.v32))
405 		off += scnprintf(buf + off, buf_size - off,
406 				 "UNCERRSTS -\t\t%#06x\n", u.v32);
407 
408 	if (!pci_read_config_dword(ndev->ntb.pdev,
409 				   GEN3_CORERRSTS_OFFSET, &u.v32))
410 		off += scnprintf(buf + off, buf_size - off,
411 				 "CORERRSTS -\t\t%#06x\n", u.v32);
412 
413 	ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
414 	kfree(buf);
415 	return ret;
416 }
417 
418 static int intel_ntb3_link_enable(struct ntb_dev *ntb,
419 				  enum ntb_speed max_speed,
420 				  enum ntb_width max_width)
421 {
422 	struct intel_ntb_dev *ndev;
423 	u32 ntb_ctl;
424 
425 	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
426 
427 	dev_dbg(&ntb->pdev->dev,
428 		"Enabling link with max_speed %d max_width %d\n",
429 		max_speed, max_width);
430 
431 	if (max_speed != NTB_SPEED_AUTO)
432 		dev_dbg(&ntb->pdev->dev, "ignoring max_speed %d\n", max_speed);
433 	if (max_width != NTB_WIDTH_AUTO)
434 		dev_dbg(&ntb->pdev->dev, "ignoring max_width %d\n", max_width);
435 
436 	ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
437 	ntb_ctl &= ~(NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK);
438 	ntb_ctl |= NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP;
439 	ntb_ctl |= NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP;
440 	iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);
441 
442 	return 0;
443 }
444 static int intel_ntb3_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
445 				   dma_addr_t addr, resource_size_t size)
446 {
447 	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
448 	unsigned long xlat_reg, limit_reg;
449 	resource_size_t bar_size, mw_size;
450 	void __iomem *mmio;
451 	u64 base, limit, reg_val;
452 	int bar;
453 
454 	if (pidx != NTB_DEF_PEER_IDX)
455 		return -EINVAL;
456 
457 	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
458 		idx += 1;
459 
460 	bar = ndev_mw_to_bar(ndev, idx);
461 	if (bar < 0)
462 		return bar;
463 
464 	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
465 
466 	if (idx == ndev->b2b_idx)
467 		mw_size = bar_size - ndev->b2b_off;
468 	else
469 		mw_size = bar_size;
470 
471 	/* hardware requires that addr is aligned to bar size */
472 	if (addr & (bar_size - 1))
473 		return -EINVAL;
474 
475 	/* make sure the range fits in the usable mw size */
476 	if (size > mw_size)
477 		return -EINVAL;
478 
479 	mmio = ndev->self_mmio;
480 	xlat_reg = ndev->xlat_reg->bar2_xlat + (idx * 0x10);
481 	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10);
482 	base = pci_resource_start(ndev->ntb.pdev, bar);
483 
484 	/* Set the limit if supported, if size is not mw_size */
485 	if (limit_reg && size != mw_size)
486 		limit = base + size;
487 	else
488 		limit = base + mw_size;
489 
490 	/* set and verify setting the translation address */
491 	iowrite64(addr, mmio + xlat_reg);
492 	reg_val = ioread64(mmio + xlat_reg);
493 	if (reg_val != addr) {
494 		iowrite64(0, mmio + xlat_reg);
495 		return -EIO;
496 	}
497 
498 	dev_dbg(&ntb->pdev->dev, "BAR %d IMBARXBASE: %#Lx\n", bar, reg_val);
499 
500 	/* set and verify setting the limit */
501 	iowrite64(limit, mmio + limit_reg);
502 	reg_val = ioread64(mmio + limit_reg);
503 	if (reg_val != limit) {
504 		iowrite64(base, mmio + limit_reg);
505 		iowrite64(0, mmio + xlat_reg);
506 		return -EIO;
507 	}
508 
509 	dev_dbg(&ntb->pdev->dev, "BAR %d IMBARXLMT: %#Lx\n", bar, reg_val);
510 
511 	/* setup the EP */
512 	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10) + 0x4000;
513 	base = ioread64(mmio + GEN3_EMBAR1_OFFSET + (8 * idx));
514 	base &= ~0xf;
515 
516 	if (limit_reg && size != mw_size)
517 		limit = base + size;
518 	else
519 		limit = base + mw_size;
520 
521 	/* set and verify setting the limit */
522 	iowrite64(limit, mmio + limit_reg);
523 	reg_val = ioread64(mmio + limit_reg);
524 	if (reg_val != limit) {
525 		iowrite64(base, mmio + limit_reg);
526 		iowrite64(0, mmio + xlat_reg);
527 		return -EIO;
528 	}
529 
530 	dev_dbg(&ntb->pdev->dev, "BAR %d EMBARXLMT: %#Lx\n", bar, reg_val);
531 
532 	return 0;
533 }
534 
535 static int intel_ntb3_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
536 {
537 	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
538 	int bit;
539 
540 	if (db_bits & ~ndev->db_valid_mask)
541 		return -EINVAL;
542 
543 	while (db_bits) {
544 		bit = __ffs(db_bits);
545 		iowrite32(1, ndev->peer_mmio +
546 				ndev->peer_reg->db_bell + (bit * 4));
547 		db_bits &= db_bits - 1;
548 	}
549 
550 	return 0;
551 }
552 
553 static u64 intel_ntb3_db_read(struct ntb_dev *ntb)
554 {
555 	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
556 
557 	return ndev_db_read(ndev,
558 			    ndev->self_mmio +
559 			    ndev->self_reg->db_clear);
560 }
561 
562 static int intel_ntb3_db_clear(struct ntb_dev *ntb, u64 db_bits)
563 {
564 	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
565 
566 	return ndev_db_write(ndev, db_bits,
567 			     ndev->self_mmio +
568 			     ndev->self_reg->db_clear);
569 }
570 
571 const struct ntb_dev_ops intel_ntb3_ops = {
572 	.mw_count		= intel_ntb_mw_count,
573 	.mw_get_align		= intel_ntb_mw_get_align,
574 	.mw_set_trans		= intel_ntb3_mw_set_trans,
575 	.peer_mw_count		= intel_ntb_peer_mw_count,
576 	.peer_mw_get_addr	= intel_ntb_peer_mw_get_addr,
577 	.link_is_up		= intel_ntb_link_is_up,
578 	.link_enable		= intel_ntb3_link_enable,
579 	.link_disable		= intel_ntb_link_disable,
580 	.db_valid_mask		= intel_ntb_db_valid_mask,
581 	.db_vector_count	= intel_ntb_db_vector_count,
582 	.db_vector_mask		= intel_ntb_db_vector_mask,
583 	.db_read		= intel_ntb3_db_read,
584 	.db_clear		= intel_ntb3_db_clear,
585 	.db_set_mask		= intel_ntb_db_set_mask,
586 	.db_clear_mask		= intel_ntb_db_clear_mask,
587 	.peer_db_addr		= intel_ntb_peer_db_addr,
588 	.peer_db_set		= intel_ntb3_peer_db_set,
589 	.spad_is_unsafe		= intel_ntb_spad_is_unsafe,
590 	.spad_count		= intel_ntb_spad_count,
591 	.spad_read		= intel_ntb_spad_read,
592 	.spad_write		= intel_ntb_spad_write,
593 	.peer_spad_addr		= intel_ntb_peer_spad_addr,
594 	.peer_spad_read		= intel_ntb_peer_spad_read,
595 	.peer_spad_write	= intel_ntb_peer_spad_write,
596 };
597 
598