cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ntb_hw_gen3.c (18009B)


      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
     61static int gen3_poll_link(struct intel_ntb_dev *ndev);
     62
     63static 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
     73static 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
     80static 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
     87static 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
     93static 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
    115static 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
    142static 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
    173static 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
    226int 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
    255ssize_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
    418int intel_ntb3_link_enable(struct ntb_dev *ntb, enum ntb_speed max_speed,
    419		enum ntb_width max_width)
    420{
    421	struct intel_ntb_dev *ndev;
    422	u32 ntb_ctl;
    423
    424	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
    425
    426	dev_dbg(&ntb->pdev->dev,
    427		"Enabling link with max_speed %d max_width %d\n",
    428		max_speed, max_width);
    429
    430	if (max_speed != NTB_SPEED_AUTO)
    431		dev_dbg(&ntb->pdev->dev, "ignoring max_speed %d\n", max_speed);
    432	if (max_width != NTB_WIDTH_AUTO)
    433		dev_dbg(&ntb->pdev->dev, "ignoring max_width %d\n", max_width);
    434
    435	ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
    436	ntb_ctl &= ~(NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK);
    437	ntb_ctl |= NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP;
    438	ntb_ctl |= NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP;
    439	iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);
    440
    441	return 0;
    442}
    443static int intel_ntb3_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
    444				   dma_addr_t addr, resource_size_t size)
    445{
    446	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
    447	unsigned long xlat_reg, limit_reg;
    448	resource_size_t bar_size, mw_size;
    449	void __iomem *mmio;
    450	u64 base, limit, reg_val;
    451	int bar;
    452
    453	if (pidx != NTB_DEF_PEER_IDX)
    454		return -EINVAL;
    455
    456	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
    457		idx += 1;
    458
    459	bar = ndev_mw_to_bar(ndev, idx);
    460	if (bar < 0)
    461		return bar;
    462
    463	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
    464
    465	if (idx == ndev->b2b_idx)
    466		mw_size = bar_size - ndev->b2b_off;
    467	else
    468		mw_size = bar_size;
    469
    470	/* hardware requires that addr is aligned to bar size */
    471	if (addr & (bar_size - 1))
    472		return -EINVAL;
    473
    474	/* make sure the range fits in the usable mw size */
    475	if (size > mw_size)
    476		return -EINVAL;
    477
    478	mmio = ndev->self_mmio;
    479	xlat_reg = ndev->xlat_reg->bar2_xlat + (idx * 0x10);
    480	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10);
    481	base = pci_resource_start(ndev->ntb.pdev, bar);
    482
    483	/* Set the limit if supported, if size is not mw_size */
    484	if (limit_reg && size != mw_size)
    485		limit = base + size;
    486	else
    487		limit = base + mw_size;
    488
    489	/* set and verify setting the translation address */
    490	iowrite64(addr, mmio + xlat_reg);
    491	reg_val = ioread64(mmio + xlat_reg);
    492	if (reg_val != addr) {
    493		iowrite64(0, mmio + xlat_reg);
    494		return -EIO;
    495	}
    496
    497	dev_dbg(&ntb->pdev->dev, "BAR %d IMBARXBASE: %#Lx\n", bar, reg_val);
    498
    499	/* set and verify setting the limit */
    500	iowrite64(limit, mmio + limit_reg);
    501	reg_val = ioread64(mmio + limit_reg);
    502	if (reg_val != limit) {
    503		iowrite64(base, mmio + limit_reg);
    504		iowrite64(0, mmio + xlat_reg);
    505		return -EIO;
    506	}
    507
    508	dev_dbg(&ntb->pdev->dev, "BAR %d IMBARXLMT: %#Lx\n", bar, reg_val);
    509
    510	/* setup the EP */
    511	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10) + 0x4000;
    512	base = ioread64(mmio + GEN3_EMBAR1_OFFSET + (8 * idx));
    513	base &= ~0xf;
    514
    515	if (limit_reg && size != mw_size)
    516		limit = base + size;
    517	else
    518		limit = base + mw_size;
    519
    520	/* set and verify setting the limit */
    521	iowrite64(limit, mmio + limit_reg);
    522	reg_val = ioread64(mmio + limit_reg);
    523	if (reg_val != limit) {
    524		iowrite64(base, mmio + limit_reg);
    525		iowrite64(0, mmio + xlat_reg);
    526		return -EIO;
    527	}
    528
    529	dev_dbg(&ntb->pdev->dev, "BAR %d EMBARXLMT: %#Lx\n", bar, reg_val);
    530
    531	return 0;
    532}
    533
    534int intel_ntb3_peer_db_addr(struct ntb_dev *ntb, phys_addr_t *db_addr,
    535				   resource_size_t *db_size,
    536				   u64 *db_data, int db_bit)
    537{
    538	phys_addr_t db_addr_base;
    539	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
    540
    541	if (unlikely(db_bit >= BITS_PER_LONG_LONG))
    542		return -EINVAL;
    543
    544	if (unlikely(BIT_ULL(db_bit) & ~ntb_ndev(ntb)->db_valid_mask))
    545		return -EINVAL;
    546
    547	ndev_db_addr(ndev, &db_addr_base, db_size, ndev->peer_addr,
    548				ndev->peer_reg->db_bell);
    549
    550	if (db_addr) {
    551		*db_addr = db_addr_base + (db_bit * 4);
    552		dev_dbg(&ndev->ntb.pdev->dev, "Peer db addr %llx db bit %d\n",
    553				*db_addr, db_bit);
    554	}
    555
    556	if (db_data) {
    557		*db_data = 1;
    558		dev_dbg(&ndev->ntb.pdev->dev, "Peer db data %llx db bit %d\n",
    559				*db_data, db_bit);
    560	}
    561
    562	return 0;
    563}
    564
    565int intel_ntb3_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
    566{
    567	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
    568	int bit;
    569
    570	if (db_bits & ~ndev->db_valid_mask)
    571		return -EINVAL;
    572
    573	while (db_bits) {
    574		bit = __ffs(db_bits);
    575		iowrite32(1, ndev->peer_mmio +
    576				ndev->peer_reg->db_bell + (bit * 4));
    577		db_bits &= db_bits - 1;
    578	}
    579
    580	return 0;
    581}
    582
    583u64 intel_ntb3_db_read(struct ntb_dev *ntb)
    584{
    585	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
    586
    587	return ndev_db_read(ndev,
    588			    ndev->self_mmio +
    589			    ndev->self_reg->db_clear);
    590}
    591
    592int intel_ntb3_db_clear(struct ntb_dev *ntb, u64 db_bits)
    593{
    594	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
    595
    596	return ndev_db_write(ndev, db_bits,
    597			     ndev->self_mmio +
    598			     ndev->self_reg->db_clear);
    599}
    600
    601const struct ntb_dev_ops intel_ntb3_ops = {
    602	.mw_count		= intel_ntb_mw_count,
    603	.mw_get_align		= intel_ntb_mw_get_align,
    604	.mw_set_trans		= intel_ntb3_mw_set_trans,
    605	.peer_mw_count		= intel_ntb_peer_mw_count,
    606	.peer_mw_get_addr	= intel_ntb_peer_mw_get_addr,
    607	.link_is_up		= intel_ntb_link_is_up,
    608	.link_enable		= intel_ntb3_link_enable,
    609	.link_disable		= intel_ntb_link_disable,
    610	.db_valid_mask		= intel_ntb_db_valid_mask,
    611	.db_vector_count	= intel_ntb_db_vector_count,
    612	.db_vector_mask		= intel_ntb_db_vector_mask,
    613	.db_read		= intel_ntb3_db_read,
    614	.db_clear		= intel_ntb3_db_clear,
    615	.db_set_mask		= intel_ntb_db_set_mask,
    616	.db_clear_mask		= intel_ntb_db_clear_mask,
    617	.peer_db_addr		= intel_ntb3_peer_db_addr,
    618	.peer_db_set		= intel_ntb3_peer_db_set,
    619	.spad_is_unsafe		= intel_ntb_spad_is_unsafe,
    620	.spad_count		= intel_ntb_spad_count,
    621	.spad_read		= intel_ntb_spad_read,
    622	.spad_write		= intel_ntb_spad_write,
    623	.peer_spad_addr		= intel_ntb_peer_spad_addr,
    624	.peer_spad_read		= intel_ntb_peer_spad_read,
    625	.peer_spad_write	= intel_ntb_peer_spad_write,
    626};
    627