xref: /linux/drivers/ntb/hw/idt/ntb_hw_idt.c (revision 72bea132f3680ee51e7ed2cee62892b6f5121909)
1 /*
2  *   This file is provided under a GPLv2 license.  When using or
3  *   redistributing this file, you may do so under that license.
4  *
5  *   GPL LICENSE SUMMARY
6  *
7  *   Copyright (C) 2016-2018 T-Platforms JSC All Rights Reserved.
8  *
9  *   This program is free software; you can redistribute it and/or modify it
10  *   under the terms and conditions of the GNU General Public License,
11  *   version 2, as published by the Free Software Foundation.
12  *
13  *   This program is distributed in the hope that it will be useful, but
14  *   WITHOUT ANY WARRANTY; without even the implied warranty of
15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
16  *   Public License for more details.
17  *
18  *   You should have received a copy of the GNU General Public License along
19  *   with this program; if not, one can be found http://www.gnu.org/licenses/.
20  *
21  *   The full GNU General Public License is included in this distribution in
22  *   the file called "COPYING".
23  *
24  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  *
36  * IDT PCIe-switch NTB Linux driver
37  *
38  * Contact Information:
39  * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
40  */
41 
42 #include <linux/stddef.h>
43 #include <linux/types.h>
44 #include <linux/kernel.h>
45 #include <linux/bitops.h>
46 #include <linux/sizes.h>
47 #include <linux/module.h>
48 #include <linux/moduleparam.h>
49 #include <linux/init.h>
50 #include <linux/interrupt.h>
51 #include <linux/spinlock.h>
52 #include <linux/mutex.h>
53 #include <linux/pci.h>
54 #include <linux/aer.h>
55 #include <linux/slab.h>
56 #include <linux/list.h>
57 #include <linux/debugfs.h>
58 #include <linux/hwmon.h>
59 #include <linux/hwmon-sysfs.h>
60 #include <linux/ntb.h>
61 
62 #include "ntb_hw_idt.h"
63 
64 #define NTB_NAME	"ntb_hw_idt"
65 #define NTB_DESC	"IDT PCI-E Non-Transparent Bridge Driver"
66 #define NTB_VER		"2.0"
67 #define NTB_IRQNAME	"ntb_irq_idt"
68 
69 MODULE_DESCRIPTION(NTB_DESC);
70 MODULE_VERSION(NTB_VER);
71 MODULE_LICENSE("GPL v2");
72 MODULE_AUTHOR("T-platforms");
73 
74 /*
75  * NT Endpoint registers table simplifying a loop access to the functionally
76  * related registers
77  */
78 static const struct idt_ntb_regs ntdata_tbl = {
79 	{ {IDT_NT_BARSETUP0,	IDT_NT_BARLIMIT0,
80 	   IDT_NT_BARLTBASE0,	IDT_NT_BARUTBASE0},
81 	  {IDT_NT_BARSETUP1,	IDT_NT_BARLIMIT1,
82 	   IDT_NT_BARLTBASE1,	IDT_NT_BARUTBASE1},
83 	  {IDT_NT_BARSETUP2,	IDT_NT_BARLIMIT2,
84 	   IDT_NT_BARLTBASE2,	IDT_NT_BARUTBASE2},
85 	  {IDT_NT_BARSETUP3,	IDT_NT_BARLIMIT3,
86 	   IDT_NT_BARLTBASE3,	IDT_NT_BARUTBASE3},
87 	  {IDT_NT_BARSETUP4,	IDT_NT_BARLIMIT4,
88 	   IDT_NT_BARLTBASE4,	IDT_NT_BARUTBASE4},
89 	  {IDT_NT_BARSETUP5,	IDT_NT_BARLIMIT5,
90 	   IDT_NT_BARLTBASE5,	IDT_NT_BARUTBASE5} },
91 	{ {IDT_NT_INMSG0,	IDT_NT_OUTMSG0,	IDT_NT_INMSGSRC0},
92 	  {IDT_NT_INMSG1,	IDT_NT_OUTMSG1,	IDT_NT_INMSGSRC1},
93 	  {IDT_NT_INMSG2,	IDT_NT_OUTMSG2,	IDT_NT_INMSGSRC2},
94 	  {IDT_NT_INMSG3,	IDT_NT_OUTMSG3,	IDT_NT_INMSGSRC3} }
95 };
96 
97 /*
98  * NT Endpoint ports data table with the corresponding pcie command, link
99  * status, control and BAR-related registers
100  */
101 static const struct idt_ntb_port portdata_tbl[IDT_MAX_NR_PORTS] = {
102 /*0*/	{ IDT_SW_NTP0_PCIECMDSTS,	IDT_SW_NTP0_PCIELCTLSTS,
103 	  IDT_SW_NTP0_NTCTL,
104 	  IDT_SW_SWPORT0CTL,		IDT_SW_SWPORT0STS,
105 	  { {IDT_SW_NTP0_BARSETUP0,	IDT_SW_NTP0_BARLIMIT0,
106 	     IDT_SW_NTP0_BARLTBASE0,	IDT_SW_NTP0_BARUTBASE0},
107 	    {IDT_SW_NTP0_BARSETUP1,	IDT_SW_NTP0_BARLIMIT1,
108 	     IDT_SW_NTP0_BARLTBASE1,	IDT_SW_NTP0_BARUTBASE1},
109 	    {IDT_SW_NTP0_BARSETUP2,	IDT_SW_NTP0_BARLIMIT2,
110 	     IDT_SW_NTP0_BARLTBASE2,	IDT_SW_NTP0_BARUTBASE2},
111 	    {IDT_SW_NTP0_BARSETUP3,	IDT_SW_NTP0_BARLIMIT3,
112 	     IDT_SW_NTP0_BARLTBASE3,	IDT_SW_NTP0_BARUTBASE3},
113 	    {IDT_SW_NTP0_BARSETUP4,	IDT_SW_NTP0_BARLIMIT4,
114 	     IDT_SW_NTP0_BARLTBASE4,	IDT_SW_NTP0_BARUTBASE4},
115 	    {IDT_SW_NTP0_BARSETUP5,	IDT_SW_NTP0_BARLIMIT5,
116 	     IDT_SW_NTP0_BARLTBASE5,	IDT_SW_NTP0_BARUTBASE5} } },
117 /*1*/	{0},
118 /*2*/	{ IDT_SW_NTP2_PCIECMDSTS,	IDT_SW_NTP2_PCIELCTLSTS,
119 	  IDT_SW_NTP2_NTCTL,
120 	  IDT_SW_SWPORT2CTL,		IDT_SW_SWPORT2STS,
121 	  { {IDT_SW_NTP2_BARSETUP0,	IDT_SW_NTP2_BARLIMIT0,
122 	     IDT_SW_NTP2_BARLTBASE0,	IDT_SW_NTP2_BARUTBASE0},
123 	    {IDT_SW_NTP2_BARSETUP1,	IDT_SW_NTP2_BARLIMIT1,
124 	     IDT_SW_NTP2_BARLTBASE1,	IDT_SW_NTP2_BARUTBASE1},
125 	    {IDT_SW_NTP2_BARSETUP2,	IDT_SW_NTP2_BARLIMIT2,
126 	     IDT_SW_NTP2_BARLTBASE2,	IDT_SW_NTP2_BARUTBASE2},
127 	    {IDT_SW_NTP2_BARSETUP3,	IDT_SW_NTP2_BARLIMIT3,
128 	     IDT_SW_NTP2_BARLTBASE3,	IDT_SW_NTP2_BARUTBASE3},
129 	    {IDT_SW_NTP2_BARSETUP4,	IDT_SW_NTP2_BARLIMIT4,
130 	     IDT_SW_NTP2_BARLTBASE4,	IDT_SW_NTP2_BARUTBASE4},
131 	    {IDT_SW_NTP2_BARSETUP5,	IDT_SW_NTP2_BARLIMIT5,
132 	     IDT_SW_NTP2_BARLTBASE5,	IDT_SW_NTP2_BARUTBASE5} } },
133 /*3*/	{0},
134 /*4*/	{ IDT_SW_NTP4_PCIECMDSTS,	IDT_SW_NTP4_PCIELCTLSTS,
135 	  IDT_SW_NTP4_NTCTL,
136 	  IDT_SW_SWPORT4CTL,		IDT_SW_SWPORT4STS,
137 	  { {IDT_SW_NTP4_BARSETUP0,	IDT_SW_NTP4_BARLIMIT0,
138 	     IDT_SW_NTP4_BARLTBASE0,	IDT_SW_NTP4_BARUTBASE0},
139 	    {IDT_SW_NTP4_BARSETUP1,	IDT_SW_NTP4_BARLIMIT1,
140 	     IDT_SW_NTP4_BARLTBASE1,	IDT_SW_NTP4_BARUTBASE1},
141 	    {IDT_SW_NTP4_BARSETUP2,	IDT_SW_NTP4_BARLIMIT2,
142 	     IDT_SW_NTP4_BARLTBASE2,	IDT_SW_NTP4_BARUTBASE2},
143 	    {IDT_SW_NTP4_BARSETUP3,	IDT_SW_NTP4_BARLIMIT3,
144 	     IDT_SW_NTP4_BARLTBASE3,	IDT_SW_NTP4_BARUTBASE3},
145 	    {IDT_SW_NTP4_BARSETUP4,	IDT_SW_NTP4_BARLIMIT4,
146 	     IDT_SW_NTP4_BARLTBASE4,	IDT_SW_NTP4_BARUTBASE4},
147 	    {IDT_SW_NTP4_BARSETUP5,	IDT_SW_NTP4_BARLIMIT5,
148 	     IDT_SW_NTP4_BARLTBASE5,	IDT_SW_NTP4_BARUTBASE5} } },
149 /*5*/	{0},
150 /*6*/	{ IDT_SW_NTP6_PCIECMDSTS,	IDT_SW_NTP6_PCIELCTLSTS,
151 	  IDT_SW_NTP6_NTCTL,
152 	  IDT_SW_SWPORT6CTL,		IDT_SW_SWPORT6STS,
153 	  { {IDT_SW_NTP6_BARSETUP0,	IDT_SW_NTP6_BARLIMIT0,
154 	     IDT_SW_NTP6_BARLTBASE0,	IDT_SW_NTP6_BARUTBASE0},
155 	    {IDT_SW_NTP6_BARSETUP1,	IDT_SW_NTP6_BARLIMIT1,
156 	     IDT_SW_NTP6_BARLTBASE1,	IDT_SW_NTP6_BARUTBASE1},
157 	    {IDT_SW_NTP6_BARSETUP2,	IDT_SW_NTP6_BARLIMIT2,
158 	     IDT_SW_NTP6_BARLTBASE2,	IDT_SW_NTP6_BARUTBASE2},
159 	    {IDT_SW_NTP6_BARSETUP3,	IDT_SW_NTP6_BARLIMIT3,
160 	     IDT_SW_NTP6_BARLTBASE3,	IDT_SW_NTP6_BARUTBASE3},
161 	    {IDT_SW_NTP6_BARSETUP4,	IDT_SW_NTP6_BARLIMIT4,
162 	     IDT_SW_NTP6_BARLTBASE4,	IDT_SW_NTP6_BARUTBASE4},
163 	    {IDT_SW_NTP6_BARSETUP5,	IDT_SW_NTP6_BARLIMIT5,
164 	     IDT_SW_NTP6_BARLTBASE5,	IDT_SW_NTP6_BARUTBASE5} } },
165 /*7*/	{0},
166 /*8*/	{ IDT_SW_NTP8_PCIECMDSTS,	IDT_SW_NTP8_PCIELCTLSTS,
167 	  IDT_SW_NTP8_NTCTL,
168 	  IDT_SW_SWPORT8CTL,		IDT_SW_SWPORT8STS,
169 	  { {IDT_SW_NTP8_BARSETUP0,	IDT_SW_NTP8_BARLIMIT0,
170 	     IDT_SW_NTP8_BARLTBASE0,	IDT_SW_NTP8_BARUTBASE0},
171 	    {IDT_SW_NTP8_BARSETUP1,	IDT_SW_NTP8_BARLIMIT1,
172 	     IDT_SW_NTP8_BARLTBASE1,	IDT_SW_NTP8_BARUTBASE1},
173 	    {IDT_SW_NTP8_BARSETUP2,	IDT_SW_NTP8_BARLIMIT2,
174 	     IDT_SW_NTP8_BARLTBASE2,	IDT_SW_NTP8_BARUTBASE2},
175 	    {IDT_SW_NTP8_BARSETUP3,	IDT_SW_NTP8_BARLIMIT3,
176 	     IDT_SW_NTP8_BARLTBASE3,	IDT_SW_NTP8_BARUTBASE3},
177 	    {IDT_SW_NTP8_BARSETUP4,	IDT_SW_NTP8_BARLIMIT4,
178 	     IDT_SW_NTP8_BARLTBASE4,	IDT_SW_NTP8_BARUTBASE4},
179 	    {IDT_SW_NTP8_BARSETUP5,	IDT_SW_NTP8_BARLIMIT5,
180 	     IDT_SW_NTP8_BARLTBASE5,	IDT_SW_NTP8_BARUTBASE5} } },
181 /*9*/	{0},
182 /*10*/	{0},
183 /*11*/	{0},
184 /*12*/	{ IDT_SW_NTP12_PCIECMDSTS,	IDT_SW_NTP12_PCIELCTLSTS,
185 	  IDT_SW_NTP12_NTCTL,
186 	  IDT_SW_SWPORT12CTL,		IDT_SW_SWPORT12STS,
187 	  { {IDT_SW_NTP12_BARSETUP0,	IDT_SW_NTP12_BARLIMIT0,
188 	     IDT_SW_NTP12_BARLTBASE0,	IDT_SW_NTP12_BARUTBASE0},
189 	    {IDT_SW_NTP12_BARSETUP1,	IDT_SW_NTP12_BARLIMIT1,
190 	     IDT_SW_NTP12_BARLTBASE1,	IDT_SW_NTP12_BARUTBASE1},
191 	    {IDT_SW_NTP12_BARSETUP2,	IDT_SW_NTP12_BARLIMIT2,
192 	     IDT_SW_NTP12_BARLTBASE2,	IDT_SW_NTP12_BARUTBASE2},
193 	    {IDT_SW_NTP12_BARSETUP3,	IDT_SW_NTP12_BARLIMIT3,
194 	     IDT_SW_NTP12_BARLTBASE3,	IDT_SW_NTP12_BARUTBASE3},
195 	    {IDT_SW_NTP12_BARSETUP4,	IDT_SW_NTP12_BARLIMIT4,
196 	     IDT_SW_NTP12_BARLTBASE4,	IDT_SW_NTP12_BARUTBASE4},
197 	    {IDT_SW_NTP12_BARSETUP5,	IDT_SW_NTP12_BARLIMIT5,
198 	     IDT_SW_NTP12_BARLTBASE5,	IDT_SW_NTP12_BARUTBASE5} } },
199 /*13*/	{0},
200 /*14*/	{0},
201 /*15*/	{0},
202 /*16*/	{ IDT_SW_NTP16_PCIECMDSTS,	IDT_SW_NTP16_PCIELCTLSTS,
203 	  IDT_SW_NTP16_NTCTL,
204 	  IDT_SW_SWPORT16CTL,		IDT_SW_SWPORT16STS,
205 	  { {IDT_SW_NTP16_BARSETUP0,	IDT_SW_NTP16_BARLIMIT0,
206 	     IDT_SW_NTP16_BARLTBASE0,	IDT_SW_NTP16_BARUTBASE0},
207 	    {IDT_SW_NTP16_BARSETUP1,	IDT_SW_NTP16_BARLIMIT1,
208 	     IDT_SW_NTP16_BARLTBASE1,	IDT_SW_NTP16_BARUTBASE1},
209 	    {IDT_SW_NTP16_BARSETUP2,	IDT_SW_NTP16_BARLIMIT2,
210 	     IDT_SW_NTP16_BARLTBASE2,	IDT_SW_NTP16_BARUTBASE2},
211 	    {IDT_SW_NTP16_BARSETUP3,	IDT_SW_NTP16_BARLIMIT3,
212 	     IDT_SW_NTP16_BARLTBASE3,	IDT_SW_NTP16_BARUTBASE3},
213 	    {IDT_SW_NTP16_BARSETUP4,	IDT_SW_NTP16_BARLIMIT4,
214 	     IDT_SW_NTP16_BARLTBASE4,	IDT_SW_NTP16_BARUTBASE4},
215 	    {IDT_SW_NTP16_BARSETUP5,	IDT_SW_NTP16_BARLIMIT5,
216 	     IDT_SW_NTP16_BARLTBASE5,	IDT_SW_NTP16_BARUTBASE5} } },
217 /*17*/	{0},
218 /*18*/	{0},
219 /*19*/	{0},
220 /*20*/	{ IDT_SW_NTP20_PCIECMDSTS,	IDT_SW_NTP20_PCIELCTLSTS,
221 	  IDT_SW_NTP20_NTCTL,
222 	  IDT_SW_SWPORT20CTL,		IDT_SW_SWPORT20STS,
223 	  { {IDT_SW_NTP20_BARSETUP0,	IDT_SW_NTP20_BARLIMIT0,
224 	     IDT_SW_NTP20_BARLTBASE0,	IDT_SW_NTP20_BARUTBASE0},
225 	    {IDT_SW_NTP20_BARSETUP1,	IDT_SW_NTP20_BARLIMIT1,
226 	     IDT_SW_NTP20_BARLTBASE1,	IDT_SW_NTP20_BARUTBASE1},
227 	    {IDT_SW_NTP20_BARSETUP2,	IDT_SW_NTP20_BARLIMIT2,
228 	     IDT_SW_NTP20_BARLTBASE2,	IDT_SW_NTP20_BARUTBASE2},
229 	    {IDT_SW_NTP20_BARSETUP3,	IDT_SW_NTP20_BARLIMIT3,
230 	     IDT_SW_NTP20_BARLTBASE3,	IDT_SW_NTP20_BARUTBASE3},
231 	    {IDT_SW_NTP20_BARSETUP4,	IDT_SW_NTP20_BARLIMIT4,
232 	     IDT_SW_NTP20_BARLTBASE4,	IDT_SW_NTP20_BARUTBASE4},
233 	    {IDT_SW_NTP20_BARSETUP5,	IDT_SW_NTP20_BARLIMIT5,
234 	     IDT_SW_NTP20_BARLTBASE5,	IDT_SW_NTP20_BARUTBASE5} } },
235 /*21*/	{0},
236 /*22*/	{0},
237 /*23*/	{0}
238 };
239 
240 /*
241  * IDT PCIe-switch partitions table with the corresponding control, status
242  * and messages control registers
243  */
244 static const struct idt_ntb_part partdata_tbl[IDT_MAX_NR_PARTS] = {
245 /*0*/	{ IDT_SW_SWPART0CTL,	IDT_SW_SWPART0STS,
246 	  {IDT_SW_SWP0MSGCTL0,	IDT_SW_SWP0MSGCTL1,
247 	   IDT_SW_SWP0MSGCTL2,	IDT_SW_SWP0MSGCTL3} },
248 /*1*/	{ IDT_SW_SWPART1CTL,	IDT_SW_SWPART1STS,
249 	  {IDT_SW_SWP1MSGCTL0,	IDT_SW_SWP1MSGCTL1,
250 	   IDT_SW_SWP1MSGCTL2,	IDT_SW_SWP1MSGCTL3} },
251 /*2*/	{ IDT_SW_SWPART2CTL,	IDT_SW_SWPART2STS,
252 	  {IDT_SW_SWP2MSGCTL0,	IDT_SW_SWP2MSGCTL1,
253 	   IDT_SW_SWP2MSGCTL2,	IDT_SW_SWP2MSGCTL3} },
254 /*3*/	{ IDT_SW_SWPART3CTL,	IDT_SW_SWPART3STS,
255 	  {IDT_SW_SWP3MSGCTL0,	IDT_SW_SWP3MSGCTL1,
256 	   IDT_SW_SWP3MSGCTL2,	IDT_SW_SWP3MSGCTL3} },
257 /*4*/	{ IDT_SW_SWPART4CTL,	IDT_SW_SWPART4STS,
258 	  {IDT_SW_SWP4MSGCTL0,	IDT_SW_SWP4MSGCTL1,
259 	   IDT_SW_SWP4MSGCTL2,	IDT_SW_SWP4MSGCTL3} },
260 /*5*/	{ IDT_SW_SWPART5CTL,	IDT_SW_SWPART5STS,
261 	  {IDT_SW_SWP5MSGCTL0,	IDT_SW_SWP5MSGCTL1,
262 	   IDT_SW_SWP5MSGCTL2,	IDT_SW_SWP5MSGCTL3} },
263 /*6*/	{ IDT_SW_SWPART6CTL,	IDT_SW_SWPART6STS,
264 	  {IDT_SW_SWP6MSGCTL0,	IDT_SW_SWP6MSGCTL1,
265 	   IDT_SW_SWP6MSGCTL2,	IDT_SW_SWP6MSGCTL3} },
266 /*7*/	{ IDT_SW_SWPART7CTL,	IDT_SW_SWPART7STS,
267 	  {IDT_SW_SWP7MSGCTL0,	IDT_SW_SWP7MSGCTL1,
268 	   IDT_SW_SWP7MSGCTL2,	IDT_SW_SWP7MSGCTL3} }
269 };
270 
271 /*
272  * DebugFS directory to place the driver debug file
273  */
274 static struct dentry *dbgfs_topdir;
275 
276 /*=============================================================================
277  *                1. IDT PCIe-switch registers IO-functions
278  *
279  *    Beside ordinary configuration space registers IDT PCIe-switch expose
280  * global configuration registers, which are used to determine state of other
281  * device ports as well as being notified of some switch-related events.
282  * Additionally all the configuration space registers of all the IDT
283  * PCIe-switch functions are mapped to the Global Address space, so each
284  * function can determine a configuration of any other PCI-function.
285  *    Functions declared in this chapter are created to encapsulate access
286  * to configuration and global registers, so the driver code just need to
287  * provide IDT NTB hardware descriptor and a register address.
288  *=============================================================================
289  */
290 
291 /*
292  * idt_nt_write() - PCI configuration space registers write method
293  * @ndev:	IDT NTB hardware driver descriptor
294  * @reg:	Register to write data to
295  * @data:	Value to write to the register
296  *
297  * IDT PCIe-switch registers are all Little endian.
298  */
299 static void idt_nt_write(struct idt_ntb_dev *ndev,
300 			 const unsigned int reg, const u32 data)
301 {
302 	/*
303 	 * It's obvious bug to request a register exceeding the maximum possible
304 	 * value as well as to have it unaligned.
305 	 */
306 	if (WARN_ON(reg > IDT_REG_PCI_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
307 		return;
308 
309 	/* Just write the value to the specified register */
310 	iowrite32(data, ndev->cfgspc + (ptrdiff_t)reg);
311 }
312 
313 /*
314  * idt_nt_read() - PCI configuration space registers read method
315  * @ndev:	IDT NTB hardware driver descriptor
316  * @reg:	Register to write data to
317  *
318  * IDT PCIe-switch Global configuration registers are all Little endian.
319  *
320  * Return: register value
321  */
322 static u32 idt_nt_read(struct idt_ntb_dev *ndev, const unsigned int reg)
323 {
324 	/*
325 	 * It's obvious bug to request a register exceeding the maximum possible
326 	 * value as well as to have it unaligned.
327 	 */
328 	if (WARN_ON(reg > IDT_REG_PCI_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
329 		return ~0;
330 
331 	/* Just read the value from the specified register */
332 	return ioread32(ndev->cfgspc + (ptrdiff_t)reg);
333 }
334 
335 /*
336  * idt_sw_write() - Global registers write method
337  * @ndev:	IDT NTB hardware driver descriptor
338  * @reg:	Register to write data to
339  * @data:	Value to write to the register
340  *
341  * IDT PCIe-switch Global configuration registers are all Little endian.
342  */
343 static void idt_sw_write(struct idt_ntb_dev *ndev,
344 			 const unsigned int reg, const u32 data)
345 {
346 	unsigned long irqflags;
347 
348 	/*
349 	 * It's obvious bug to request a register exceeding the maximum possible
350 	 * value as well as to have it unaligned.
351 	 */
352 	if (WARN_ON(reg > IDT_REG_SW_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
353 		return;
354 
355 	/* Lock GASA registers operations */
356 	spin_lock_irqsave(&ndev->gasa_lock, irqflags);
357 	/* Set the global register address */
358 	iowrite32((u32)reg, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASAADDR);
359 	/* Put the new value of the register */
360 	iowrite32(data, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASADATA);
361 	/* Unlock GASA registers operations */
362 	spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
363 }
364 
365 /*
366  * idt_sw_read() - Global registers read method
367  * @ndev:	IDT NTB hardware driver descriptor
368  * @reg:	Register to write data to
369  *
370  * IDT PCIe-switch Global configuration registers are all Little endian.
371  *
372  * Return: register value
373  */
374 static u32 idt_sw_read(struct idt_ntb_dev *ndev, const unsigned int reg)
375 {
376 	unsigned long irqflags;
377 	u32 data;
378 
379 	/*
380 	 * It's obvious bug to request a register exceeding the maximum possible
381 	 * value as well as to have it unaligned.
382 	 */
383 	if (WARN_ON(reg > IDT_REG_SW_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
384 		return ~0;
385 
386 	/* Lock GASA registers operations */
387 	spin_lock_irqsave(&ndev->gasa_lock, irqflags);
388 	/* Set the global register address */
389 	iowrite32((u32)reg, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASAADDR);
390 	/* Get the data of the register (read ops acts as MMIO barrier) */
391 	data = ioread32(ndev->cfgspc + (ptrdiff_t)IDT_NT_GASADATA);
392 	/* Unlock GASA registers operations */
393 	spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
394 
395 	return data;
396 }
397 
398 /*
399  * idt_reg_set_bits() - set bits of a passed register
400  * @ndev:	IDT NTB hardware driver descriptor
401  * @reg:	Register to change bits of
402  * @reg_lock:	Register access spin lock
403  * @valid_mask:	Mask of valid bits
404  * @set_bits:	Bitmask to set
405  *
406  * Helper method to check whether a passed bitfield is valid and set
407  * corresponding bits of a register.
408  *
409  * WARNING! Make sure the passed register isn't accessed over plane
410  * idt_nt_write() method (read method is ok to be used concurrently).
411  *
412  * Return: zero on success, negative error on invalid bitmask.
413  */
414 static inline int idt_reg_set_bits(struct idt_ntb_dev *ndev, unsigned int reg,
415 				   spinlock_t *reg_lock,
416 				   u64 valid_mask, u64 set_bits)
417 {
418 	unsigned long irqflags;
419 	u32 data;
420 
421 	if (set_bits & ~(u64)valid_mask)
422 		return -EINVAL;
423 
424 	/* Lock access to the register unless the change is written back */
425 	spin_lock_irqsave(reg_lock, irqflags);
426 	data = idt_nt_read(ndev, reg) | (u32)set_bits;
427 	idt_nt_write(ndev, reg, data);
428 	/* Unlock the register */
429 	spin_unlock_irqrestore(reg_lock, irqflags);
430 
431 	return 0;
432 }
433 
434 /*
435  * idt_reg_clear_bits() - clear bits of a passed register
436  * @ndev:	IDT NTB hardware driver descriptor
437  * @reg:	Register to change bits of
438  * @reg_lock:	Register access spin lock
439  * @set_bits:	Bitmask to clear
440  *
441  * Helper method to check whether a passed bitfield is valid and clear
442  * corresponding bits of a register.
443  *
444  * NOTE! Invalid bits are always considered cleared so it's not an error
445  * to clear them over.
446  *
447  * WARNING! Make sure the passed register isn't accessed over plane
448  * idt_nt_write() method (read method is ok to use concurrently).
449  */
450 static inline void idt_reg_clear_bits(struct idt_ntb_dev *ndev,
451 				     unsigned int reg, spinlock_t *reg_lock,
452 				     u64 clear_bits)
453 {
454 	unsigned long irqflags;
455 	u32 data;
456 
457 	/* Lock access to the register unless the change is written back */
458 	spin_lock_irqsave(reg_lock, irqflags);
459 	data = idt_nt_read(ndev, reg) & ~(u32)clear_bits;
460 	idt_nt_write(ndev, reg, data);
461 	/* Unlock the register */
462 	spin_unlock_irqrestore(reg_lock, irqflags);
463 }
464 
465 /*===========================================================================
466  *                           2. Ports operations
467  *
468  *    IDT PCIe-switches can have from 3 up to 8 ports with possible
469  * NT-functions enabled. So all the possible ports need to be scanned looking
470  * for NTB activated. NTB API will have enumerated only the ports with NTB.
471  *===========================================================================
472  */
473 
474 /*
475  * idt_scan_ports() - scan IDT PCIe-switch ports collecting info in the tables
476  * @ndev:	Pointer to the PCI device descriptor
477  *
478  * Return: zero on success, otherwise a negative error number.
479  */
480 static int idt_scan_ports(struct idt_ntb_dev *ndev)
481 {
482 	unsigned char pidx, port, part;
483 	u32 data, portsts, partsts;
484 
485 	/* Retrieve the local port number */
486 	data = idt_nt_read(ndev, IDT_NT_PCIELCAP);
487 	ndev->port = GET_FIELD(PCIELCAP_PORTNUM, data);
488 
489 	/* Retrieve the local partition number */
490 	portsts = idt_sw_read(ndev, portdata_tbl[ndev->port].sts);
491 	ndev->part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
492 
493 	/* Initialize port/partition -> index tables with invalid values */
494 	memset(ndev->port_idx_map, -EINVAL, sizeof(ndev->port_idx_map));
495 	memset(ndev->part_idx_map, -EINVAL, sizeof(ndev->part_idx_map));
496 
497 	/*
498 	 * Walk over all the possible ports checking whether any of them has
499 	 * NT-function activated
500 	 */
501 	ndev->peer_cnt = 0;
502 	for (pidx = 0; pidx < ndev->swcfg->port_cnt; pidx++) {
503 		port = ndev->swcfg->ports[pidx];
504 		/* Skip local port */
505 		if (port == ndev->port)
506 			continue;
507 
508 		/* Read the port status register to get it partition */
509 		portsts = idt_sw_read(ndev, portdata_tbl[port].sts);
510 		part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
511 
512 		/* Retrieve the partition status */
513 		partsts = idt_sw_read(ndev, partdata_tbl[part].sts);
514 		/* Check if partition state is active and port has NTB */
515 		if (IS_FLD_SET(SWPARTxSTS_STATE, partsts, ACT) &&
516 		    (IS_FLD_SET(SWPORTxSTS_MODE, portsts, NT) ||
517 		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNT) ||
518 		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNTDMA) ||
519 		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, NTDMA))) {
520 			/* Save the port and partition numbers */
521 			ndev->peers[ndev->peer_cnt].port = port;
522 			ndev->peers[ndev->peer_cnt].part = part;
523 			/* Fill in the port/partition -> index tables */
524 			ndev->port_idx_map[port] = ndev->peer_cnt;
525 			ndev->part_idx_map[part] = ndev->peer_cnt;
526 			ndev->peer_cnt++;
527 		}
528 	}
529 
530 	dev_dbg(&ndev->ntb.pdev->dev, "Local port: %hhu, num of peers: %hhu\n",
531 		ndev->port, ndev->peer_cnt);
532 
533 	/* It's useless to have this driver loaded if there is no any peer */
534 	if (ndev->peer_cnt == 0) {
535 		dev_warn(&ndev->ntb.pdev->dev, "No active peer found\n");
536 		return -ENODEV;
537 	}
538 
539 	return 0;
540 }
541 
542 /*
543  * idt_ntb_port_number() - get the local port number
544  * @ntb:	NTB device context.
545  *
546  * Return: the local port number
547  */
548 static int idt_ntb_port_number(struct ntb_dev *ntb)
549 {
550 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
551 
552 	return ndev->port;
553 }
554 
555 /*
556  * idt_ntb_peer_port_count() - get the number of peer ports
557  * @ntb:	NTB device context.
558  *
559  * Return the count of detected peer NT-functions.
560  *
561  * Return: number of peer ports
562  */
563 static int idt_ntb_peer_port_count(struct ntb_dev *ntb)
564 {
565 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
566 
567 	return ndev->peer_cnt;
568 }
569 
570 /*
571  * idt_ntb_peer_port_number() - get peer port by given index
572  * @ntb:	NTB device context.
573  * @pidx:	Peer port index.
574  *
575  * Return: peer port or negative error
576  */
577 static int idt_ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
578 {
579 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
580 
581 	if (pidx < 0 || ndev->peer_cnt <= pidx)
582 		return -EINVAL;
583 
584 	/* Return the detected NT-function port number */
585 	return ndev->peers[pidx].port;
586 }
587 
588 /*
589  * idt_ntb_peer_port_idx() - get peer port index by given port number
590  * @ntb:	NTB device context.
591  * @port:	Peer port number.
592  *
593  * Internal port -> index table is pre-initialized with -EINVAL values,
594  * so we just need to return it value
595  *
596  * Return: peer NT-function port index or negative error
597  */
598 static int idt_ntb_peer_port_idx(struct ntb_dev *ntb, int port)
599 {
600 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
601 
602 	if (port < 0 || IDT_MAX_NR_PORTS <= port)
603 		return -EINVAL;
604 
605 	return ndev->port_idx_map[port];
606 }
607 
608 /*===========================================================================
609  *                         3. Link status operations
610  *    There is no any ready-to-use method to have peer ports notified if NTB
611  * link is set up or got down. Instead global signal can be used instead.
612  * In case if any one of ports changes local NTB link state, it sends
613  * global signal and clears corresponding global state bit. Then all the ports
614  * receive a notification of that, so to make client driver being aware of
615  * possible NTB link change.
616  *    Additionally each of active NT-functions is subscribed to PCIe-link
617  * state changes of peer ports.
618  *===========================================================================
619  */
620 
621 static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev);
622 
623 /*
624  * idt_init_link() - Initialize NTB link state notification subsystem
625  * @ndev:	IDT NTB hardware driver descriptor
626  *
627  * Function performs the basic initialization of some global registers
628  * needed to enable IRQ-based notifications of PCIe Link Up/Down and
629  * Global Signal events.
630  * NOTE Since it's not possible to determine when all the NTB peer drivers are
631  * unloaded as well as have those registers accessed concurrently, we must
632  * preinitialize them with the same value and leave it uncleared on local
633  * driver unload.
634  */
635 static void idt_init_link(struct idt_ntb_dev *ndev)
636 {
637 	u32 part_mask, port_mask, se_mask;
638 	unsigned char pidx;
639 
640 	/* Initialize spin locker of Mapping Table access registers */
641 	spin_lock_init(&ndev->mtbl_lock);
642 
643 	/* Walk over all detected peers collecting port and partition masks */
644 	port_mask = ~BIT(ndev->port);
645 	part_mask = ~BIT(ndev->part);
646 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
647 		port_mask &= ~BIT(ndev->peers[pidx].port);
648 		part_mask &= ~BIT(ndev->peers[pidx].part);
649 	}
650 
651 	/* Clean the Link Up/Down and GLobal Signal status registers */
652 	idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
653 	idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
654 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
655 
656 	/* Unmask NT-activated partitions to receive Global Switch events */
657 	idt_sw_write(ndev, IDT_SW_SEPMSK, part_mask);
658 
659 	/* Enable PCIe Link Up events of NT-activated ports */
660 	idt_sw_write(ndev, IDT_SW_SELINKUPMSK, port_mask);
661 
662 	/* Enable PCIe Link Down events of NT-activated ports */
663 	idt_sw_write(ndev, IDT_SW_SELINKDNMSK, port_mask);
664 
665 	/* Unmask NT-activated partitions to receive Global Signal events */
666 	idt_sw_write(ndev, IDT_SW_SEGSIGMSK, part_mask);
667 
668 	/* Unmask Link Up/Down and Global Switch Events */
669 	se_mask = ~(IDT_SEMSK_LINKUP | IDT_SEMSK_LINKDN | IDT_SEMSK_GSIGNAL);
670 	idt_sw_write(ndev, IDT_SW_SEMSK, se_mask);
671 
672 	dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events initialized");
673 }
674 
675 /*
676  * idt_deinit_link() - deinitialize link subsystem
677  * @ndev:	IDT NTB hardware driver descriptor
678  *
679  * Just disable the link back.
680  */
681 static void idt_deinit_link(struct idt_ntb_dev *ndev)
682 {
683 	/* Disable the link */
684 	idt_ntb_local_link_disable(ndev);
685 
686 	dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events deinitialized");
687 }
688 
689 /*
690  * idt_se_isr() - switch events ISR
691  * @ndev:	IDT NTB hardware driver descriptor
692  * @ntint_sts:	NT-function interrupt status
693  *
694  * This driver doesn't support IDT PCIe-switch dynamic reconfigurations,
695  * Failover capability, etc, so switch events are utilized to notify of
696  * PCIe and NTB link events.
697  * The method is called from PCIe ISR bottom-half routine.
698  */
699 static void idt_se_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
700 {
701 	u32 sests;
702 
703 	/* Read Switch Events status */
704 	sests = idt_sw_read(ndev, IDT_SW_SESTS);
705 
706 	/* Clean the Link Up/Down and Global Signal status registers */
707 	idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
708 	idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
709 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
710 
711 	/* Clean the corresponding interrupt bit */
712 	idt_nt_write(ndev, IDT_NT_NTINTSTS, IDT_NTINTSTS_SEVENT);
713 
714 	dev_dbg(&ndev->ntb.pdev->dev, "SE IRQ detected %#08x (SESTS %#08x)",
715 			  ntint_sts, sests);
716 
717 	/* Notify the client driver of possible link state change */
718 	ntb_link_event(&ndev->ntb);
719 }
720 
721 /*
722  * idt_ntb_local_link_enable() - enable the local NTB link.
723  * @ndev:	IDT NTB hardware driver descriptor
724  *
725  * In order to enable the NTB link we need:
726  * - enable Completion TLPs translation
727  * - initialize mapping table to enable the Request ID translation
728  * - notify peers of NTB link state change
729  */
730 static void idt_ntb_local_link_enable(struct idt_ntb_dev *ndev)
731 {
732 	u32 reqid, mtbldata = 0;
733 	unsigned long irqflags;
734 
735 	/* Enable the ID protection and Completion TLPs translation */
736 	idt_nt_write(ndev, IDT_NT_NTCTL, IDT_NTCTL_CPEN);
737 
738 	/* Retrieve the current Requester ID (Bus:Device:Function) */
739 	reqid = idt_nt_read(ndev, IDT_NT_REQIDCAP);
740 
741 	/*
742 	 * Set the corresponding NT Mapping table entry of port partition index
743 	 * with the data to perform the Request ID translation
744 	 */
745 	mtbldata = SET_FIELD(NTMTBLDATA_REQID, 0, reqid) |
746 		   SET_FIELD(NTMTBLDATA_PART, 0, ndev->part) |
747 		   IDT_NTMTBLDATA_VALID;
748 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
749 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
750 	idt_nt_write(ndev, IDT_NT_NTMTBLDATA, mtbldata);
751 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
752 
753 	/* Notify the peers by setting and clearing the global signal bit */
754 	idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
755 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
756 }
757 
758 /*
759  * idt_ntb_local_link_disable() - disable the local NTB link.
760  * @ndev:	IDT NTB hardware driver descriptor
761  *
762  * In order to enable the NTB link we need:
763  * - disable Completion TLPs translation
764  * - clear corresponding mapping table entry
765  * - notify peers of NTB link state change
766  */
767 static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev)
768 {
769 	unsigned long irqflags;
770 
771 	/* Disable Completion TLPs translation */
772 	idt_nt_write(ndev, IDT_NT_NTCTL, 0);
773 
774 	/* Clear the corresponding NT Mapping table entry */
775 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
776 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
777 	idt_nt_write(ndev, IDT_NT_NTMTBLDATA, 0);
778 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
779 
780 	/* Notify the peers by setting and clearing the global signal bit */
781 	idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
782 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
783 }
784 
785 /*
786  * idt_ntb_local_link_is_up() - test wethter local NTB link is up
787  * @ndev:	IDT NTB hardware driver descriptor
788  *
789  * Local link is up under the following conditions:
790  * - Bus mastering is enabled
791  * - NTCTL has Completion TLPs translation enabled
792  * - Mapping table permits Request TLPs translation
793  * NOTE: We don't need to check PCIe link state since it's obviously
794  * up while we are able to communicate with IDT PCIe-switch
795  *
796  * Return: true if link is up, otherwise false
797  */
798 static bool idt_ntb_local_link_is_up(struct idt_ntb_dev *ndev)
799 {
800 	unsigned long irqflags;
801 	u32 data;
802 
803 	/* Read the local Bus Master Enable status */
804 	data = idt_nt_read(ndev, IDT_NT_PCICMDSTS);
805 	if (!(data & IDT_PCICMDSTS_BME))
806 		return false;
807 
808 	/* Read the local Completion TLPs translation enable status */
809 	data = idt_nt_read(ndev, IDT_NT_NTCTL);
810 	if (!(data & IDT_NTCTL_CPEN))
811 		return false;
812 
813 	/* Read Mapping table entry corresponding to the local partition */
814 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
815 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
816 	data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
817 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
818 
819 	return !!(data & IDT_NTMTBLDATA_VALID);
820 }
821 
822 /*
823  * idt_ntb_peer_link_is_up() - test whether peer NTB link is up
824  * @ndev:	IDT NTB hardware driver descriptor
825  * @pidx:	Peer port index
826  *
827  * Peer link is up under the following conditions:
828  * - PCIe link is up
829  * - Bus mastering is enabled
830  * - NTCTL has Completion TLPs translation enabled
831  * - Mapping table permits Request TLPs translation
832  *
833  * Return: true if link is up, otherwise false
834  */
835 static bool idt_ntb_peer_link_is_up(struct idt_ntb_dev *ndev, int pidx)
836 {
837 	unsigned long irqflags;
838 	unsigned char port;
839 	u32 data;
840 
841 	/* Retrieve the device port number */
842 	port = ndev->peers[pidx].port;
843 
844 	/* Check whether PCIe link is up */
845 	data = idt_sw_read(ndev, portdata_tbl[port].sts);
846 	if (!(data & IDT_SWPORTxSTS_LINKUP))
847 		return false;
848 
849 	/* Check whether bus mastering is enabled on the peer port */
850 	data = idt_sw_read(ndev, portdata_tbl[port].pcicmdsts);
851 	if (!(data & IDT_PCICMDSTS_BME))
852 		return false;
853 
854 	/* Check if Completion TLPs translation is enabled on the peer port */
855 	data = idt_sw_read(ndev, portdata_tbl[port].ntctl);
856 	if (!(data & IDT_NTCTL_CPEN))
857 		return false;
858 
859 	/* Read Mapping table entry corresponding to the peer partition */
860 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
861 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->peers[pidx].part);
862 	data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
863 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
864 
865 	return !!(data & IDT_NTMTBLDATA_VALID);
866 }
867 
868 /*
869  * idt_ntb_link_is_up() - get the current ntb link state (NTB API callback)
870  * @ntb:	NTB device context.
871  * @speed:	OUT - The link speed expressed as PCIe generation number.
872  * @width:	OUT - The link width expressed as the number of PCIe lanes.
873  *
874  * Get the bitfield of NTB link states for all peer ports
875  *
876  * Return: bitfield of indexed ports link state: bit is set/cleared if the
877  *         link is up/down respectively.
878  */
879 static u64 idt_ntb_link_is_up(struct ntb_dev *ntb,
880 			      enum ntb_speed *speed, enum ntb_width *width)
881 {
882 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
883 	unsigned char pidx;
884 	u64 status;
885 	u32 data;
886 
887 	/* Retrieve the local link speed and width */
888 	if (speed != NULL || width != NULL) {
889 		data = idt_nt_read(ndev, IDT_NT_PCIELCTLSTS);
890 		if (speed != NULL)
891 			*speed = GET_FIELD(PCIELCTLSTS_CLS, data);
892 		if (width != NULL)
893 			*width = GET_FIELD(PCIELCTLSTS_NLW, data);
894 	}
895 
896 	/* If local NTB link isn't up then all the links are considered down */
897 	if (!idt_ntb_local_link_is_up(ndev))
898 		return 0;
899 
900 	/* Collect all the peer ports link states into the bitfield */
901 	status = 0;
902 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
903 		if (idt_ntb_peer_link_is_up(ndev, pidx))
904 			status |= ((u64)1 << pidx);
905 	}
906 
907 	return status;
908 }
909 
910 /*
911  * idt_ntb_link_enable() - enable local port ntb link (NTB API callback)
912  * @ntb:	NTB device context.
913  * @max_speed:	The maximum link speed expressed as PCIe generation number.
914  * @max_width:	The maximum link width expressed as the number of PCIe lanes.
915  *
916  * Enable just local NTB link. PCIe link parameters are ignored.
917  *
918  * Return: always zero.
919  */
920 static int idt_ntb_link_enable(struct ntb_dev *ntb, enum ntb_speed speed,
921 			       enum ntb_width width)
922 {
923 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
924 
925 	/* Just enable the local NTB link */
926 	idt_ntb_local_link_enable(ndev);
927 
928 	dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link enabled");
929 
930 	return 0;
931 }
932 
933 /*
934  * idt_ntb_link_disable() - disable local port ntb link (NTB API callback)
935  * @ntb:	NTB device context.
936  *
937  * Disable just local NTB link.
938  *
939  * Return: always zero.
940  */
941 static int idt_ntb_link_disable(struct ntb_dev *ntb)
942 {
943 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
944 
945 	/* Just disable the local NTB link */
946 	idt_ntb_local_link_disable(ndev);
947 
948 	dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link disabled");
949 
950 	return 0;
951 }
952 
953 /*=============================================================================
954  *                         4. Memory Window operations
955  *
956  *    IDT PCIe-switches have two types of memory windows: MWs with direct
957  * address translation and MWs with LUT based translation. The first type of
958  * MWs is simple map of corresponding BAR address space to a memory space
959  * of specified target port. So it implemets just ont-to-one mapping. Lookup
960  * table in its turn can map one BAR address space to up to 24 different
961  * memory spaces of different ports.
962  *    NT-functions BARs can be turned on to implement either direct or lookup
963  * table based address translations, so:
964  * BAR0 - NT configuration registers space/direct address translation
965  * BAR1 - direct address translation/upper address of BAR0x64
966  * BAR2 - direct address translation/Lookup table with either 12 or 24 entries
967  * BAR3 - direct address translation/upper address of BAR2x64
968  * BAR4 - direct address translation/Lookup table with either 12 or 24 entries
969  * BAR5 - direct address translation/upper address of BAR4x64
970  *    Additionally BAR2 and BAR4 can't have 24-entries LUT enabled at the same
971  * time. Since the BARs setup can be rather complicated this driver implements
972  * a scanning algorithm to have all the possible memory windows configuration
973  * covered.
974  *
975  * NOTE 1 BAR setup must be done before Linux kernel enumerated NT-function
976  * of any port, so this driver would have memory windows configurations fixed.
977  * In this way all initializations must be performed either by platform BIOS
978  * or using EEPROM connected to IDT PCIe-switch master SMBus.
979  *
980  * NOTE 2 This driver expects BAR0 mapping NT-function configuration space.
981  * Easy calculation can give us an upper boundary of 29 possible memory windows
982  * per each NT-function if all the BARs are of 32bit type.
983  *=============================================================================
984  */
985 
986 /*
987  * idt_get_mw_count() - get memory window count
988  * @mw_type:	Memory window type
989  *
990  * Return: number of memory windows with respect to the BAR type
991  */
992 static inline unsigned char idt_get_mw_count(enum idt_mw_type mw_type)
993 {
994 	switch (mw_type) {
995 	case IDT_MW_DIR:
996 		return 1;
997 	case IDT_MW_LUT12:
998 		return 12;
999 	case IDT_MW_LUT24:
1000 		return 24;
1001 	default:
1002 		break;
1003 	}
1004 
1005 	return 0;
1006 }
1007 
1008 /*
1009  * idt_get_mw_name() - get memory window name
1010  * @mw_type:	Memory window type
1011  *
1012  * Return: pointer to a string with name
1013  */
1014 static inline char *idt_get_mw_name(enum idt_mw_type mw_type)
1015 {
1016 	switch (mw_type) {
1017 	case IDT_MW_DIR:
1018 		return "DIR  ";
1019 	case IDT_MW_LUT12:
1020 		return "LUT12";
1021 	case IDT_MW_LUT24:
1022 		return "LUT24";
1023 	default:
1024 		break;
1025 	}
1026 
1027 	return "unknown";
1028 }
1029 
1030 /*
1031  * idt_scan_mws() - scan memory windows of the port
1032  * @ndev:	IDT NTB hardware driver descriptor
1033  * @port:	Port to get number of memory windows for
1034  * @mw_cnt:	Out - number of memory windows
1035  *
1036  * It walks over BAR setup registers of the specified port and determines
1037  * the memory windows parameters if any activated.
1038  *
1039  * Return: array of memory windows
1040  */
1041 static struct idt_mw_cfg *idt_scan_mws(struct idt_ntb_dev *ndev, int port,
1042 				       unsigned char *mw_cnt)
1043 {
1044 	struct idt_mw_cfg mws[IDT_MAX_NR_MWS], *ret_mws;
1045 	const struct idt_ntb_bar *bars;
1046 	enum idt_mw_type mw_type;
1047 	unsigned char widx, bidx, en_cnt;
1048 	bool bar_64bit = false;
1049 	int aprt_size;
1050 	u32 data;
1051 
1052 	/* Retrieve the array of the BARs registers */
1053 	bars = portdata_tbl[port].bars;
1054 
1055 	/* Scan all the BARs belonging to the port */
1056 	*mw_cnt = 0;
1057 	for (bidx = 0; bidx < IDT_BAR_CNT; bidx += 1 + bar_64bit) {
1058 		/* Read BARSETUP register value */
1059 		data = idt_sw_read(ndev, bars[bidx].setup);
1060 
1061 		/* Skip disabled BARs */
1062 		if (!(data & IDT_BARSETUP_EN)) {
1063 			bar_64bit = false;
1064 			continue;
1065 		}
1066 
1067 		/* Skip next BARSETUP if current one has 64bit addressing */
1068 		bar_64bit = IS_FLD_SET(BARSETUP_TYPE, data, 64);
1069 
1070 		/* Skip configuration space mapping BARs */
1071 		if (data & IDT_BARSETUP_MODE_CFG)
1072 			continue;
1073 
1074 		/* Retrieve MW type/entries count and aperture size */
1075 		mw_type = GET_FIELD(BARSETUP_ATRAN, data);
1076 		en_cnt = idt_get_mw_count(mw_type);
1077 		aprt_size = (u64)1 << GET_FIELD(BARSETUP_SIZE, data);
1078 
1079 		/* Save configurations of all available memory windows */
1080 		for (widx = 0; widx < en_cnt; widx++, (*mw_cnt)++) {
1081 			/*
1082 			 * IDT can expose a limited number of MWs, so it's bug
1083 			 * to have more than the driver expects
1084 			 */
1085 			if (*mw_cnt >= IDT_MAX_NR_MWS)
1086 				return ERR_PTR(-EINVAL);
1087 
1088 			/* Save basic MW info */
1089 			mws[*mw_cnt].type = mw_type;
1090 			mws[*mw_cnt].bar = bidx;
1091 			mws[*mw_cnt].idx = widx;
1092 			/* It's always DWORD aligned */
1093 			mws[*mw_cnt].addr_align = IDT_TRANS_ALIGN;
1094 			/* DIR and LUT approachs differently configure MWs */
1095 			if (mw_type == IDT_MW_DIR)
1096 				mws[*mw_cnt].size_max = aprt_size;
1097 			else if (mw_type == IDT_MW_LUT12)
1098 				mws[*mw_cnt].size_max = aprt_size / 16;
1099 			else
1100 				mws[*mw_cnt].size_max = aprt_size / 32;
1101 			mws[*mw_cnt].size_align = (mw_type == IDT_MW_DIR) ?
1102 				IDT_DIR_SIZE_ALIGN : mws[*mw_cnt].size_max;
1103 		}
1104 	}
1105 
1106 	/* Allocate memory for memory window descriptors */
1107 	ret_mws = devm_kcalloc(&ndev->ntb.pdev->dev, *mw_cnt, sizeof(*ret_mws),
1108 			       GFP_KERNEL);
1109 	if (!ret_mws)
1110 		return ERR_PTR(-ENOMEM);
1111 
1112 	/* Copy the info of detected memory windows */
1113 	memcpy(ret_mws, mws, (*mw_cnt)*sizeof(*ret_mws));
1114 
1115 	return ret_mws;
1116 }
1117 
1118 /*
1119  * idt_init_mws() - initialize memory windows subsystem
1120  * @ndev:	IDT NTB hardware driver descriptor
1121  *
1122  * Scan BAR setup registers of local and peer ports to determine the
1123  * outbound and inbound memory windows parameters
1124  *
1125  * Return: zero on success, otherwise a negative error number
1126  */
1127 static int idt_init_mws(struct idt_ntb_dev *ndev)
1128 {
1129 	struct idt_ntb_peer *peer;
1130 	unsigned char pidx;
1131 
1132 	/* Scan memory windows of the local port */
1133 	ndev->mws = idt_scan_mws(ndev, ndev->port, &ndev->mw_cnt);
1134 	if (IS_ERR(ndev->mws)) {
1135 		dev_err(&ndev->ntb.pdev->dev,
1136 			"Failed to scan mws of local port %hhu", ndev->port);
1137 		return PTR_ERR(ndev->mws);
1138 	}
1139 
1140 	/* Scan memory windows of the peer ports */
1141 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
1142 		peer = &ndev->peers[pidx];
1143 		peer->mws = idt_scan_mws(ndev, peer->port, &peer->mw_cnt);
1144 		if (IS_ERR(peer->mws)) {
1145 			dev_err(&ndev->ntb.pdev->dev,
1146 				"Failed to scan mws of port %hhu", peer->port);
1147 			return PTR_ERR(peer->mws);
1148 		}
1149 	}
1150 
1151 	/* Initialize spin locker of the LUT registers */
1152 	spin_lock_init(&ndev->lut_lock);
1153 
1154 	dev_dbg(&ndev->ntb.pdev->dev, "Outbound and inbound MWs initialized");
1155 
1156 	return 0;
1157 }
1158 
1159 /*
1160  * idt_ntb_mw_count() - number of inbound memory windows (NTB API callback)
1161  * @ntb:	NTB device context.
1162  * @pidx:	Port index of peer device.
1163  *
1164  * The value is returned for the specified peer, so generally speaking it can
1165  * be different for different port depending on the IDT PCIe-switch
1166  * initialization.
1167  *
1168  * Return: the number of memory windows.
1169  */
1170 static int idt_ntb_mw_count(struct ntb_dev *ntb, int pidx)
1171 {
1172 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1173 
1174 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1175 		return -EINVAL;
1176 
1177 	return ndev->peers[pidx].mw_cnt;
1178 }
1179 
1180 /*
1181  * idt_ntb_mw_get_align() - inbound memory window parameters (NTB API callback)
1182  * @ntb:	NTB device context.
1183  * @pidx:	Port index of peer device.
1184  * @widx:	Memory window index.
1185  * @addr_align:	OUT - the base alignment for translating the memory window
1186  * @size_align:	OUT - the size alignment for translating the memory window
1187  * @size_max:	OUT - the maximum size of the memory window
1188  *
1189  * The peer memory window parameters have already been determined, so just
1190  * return the corresponding values, which mustn't change within session.
1191  *
1192  * Return: Zero on success, otherwise a negative error number.
1193  */
1194 static int idt_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx,
1195 				resource_size_t *addr_align,
1196 				resource_size_t *size_align,
1197 				resource_size_t *size_max)
1198 {
1199 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1200 	struct idt_ntb_peer *peer;
1201 
1202 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1203 		return -EINVAL;
1204 
1205 	peer = &ndev->peers[pidx];
1206 
1207 	if (widx < 0 || peer->mw_cnt <= widx)
1208 		return -EINVAL;
1209 
1210 	if (addr_align != NULL)
1211 		*addr_align = peer->mws[widx].addr_align;
1212 
1213 	if (size_align != NULL)
1214 		*size_align = peer->mws[widx].size_align;
1215 
1216 	if (size_max != NULL)
1217 		*size_max = peer->mws[widx].size_max;
1218 
1219 	return 0;
1220 }
1221 
1222 /*
1223  * idt_ntb_peer_mw_count() - number of outbound memory windows
1224  *			     (NTB API callback)
1225  * @ntb:	NTB device context.
1226  *
1227  * Outbound memory windows parameters have been determined based on the
1228  * BAR setup registers value, which are mostly constants within one session.
1229  *
1230  * Return: the number of memory windows.
1231  */
1232 static int idt_ntb_peer_mw_count(struct ntb_dev *ntb)
1233 {
1234 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1235 
1236 	return ndev->mw_cnt;
1237 }
1238 
1239 /*
1240  * idt_ntb_peer_mw_get_addr() - get map address of an outbound memory window
1241  *				(NTB API callback)
1242  * @ntb:	NTB device context.
1243  * @widx:	Memory window index (within ntb_peer_mw_count() return value).
1244  * @base:	OUT - the base address of mapping region.
1245  * @size:	OUT - the size of mapping region.
1246  *
1247  * Return just parameters of BAR resources mapping. Size reflects just the size
1248  * of the resource
1249  *
1250  * Return: Zero on success, otherwise a negative error number.
1251  */
1252 static int idt_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int widx,
1253 				    phys_addr_t *base, resource_size_t *size)
1254 {
1255 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1256 
1257 	if (widx < 0 || ndev->mw_cnt <= widx)
1258 		return -EINVAL;
1259 
1260 	/* Mapping address is just properly shifted BAR resource start */
1261 	if (base != NULL)
1262 		*base = pci_resource_start(ntb->pdev, ndev->mws[widx].bar) +
1263 			ndev->mws[widx].idx * ndev->mws[widx].size_max;
1264 
1265 	/* Mapping size has already been calculated at MWs scanning */
1266 	if (size != NULL)
1267 		*size = ndev->mws[widx].size_max;
1268 
1269 	return 0;
1270 }
1271 
1272 /*
1273  * idt_ntb_peer_mw_set_trans() - set a translation address of a memory window
1274  *				 (NTB API callback)
1275  * @ntb:	NTB device context.
1276  * @pidx:	Port index of peer device the translation address received from.
1277  * @widx:	Memory window index.
1278  * @addr:	The dma address of the shared memory to access.
1279  * @size:	The size of the shared memory to access.
1280  *
1281  * The Direct address translation and LUT base translation is initialized a
1282  * bit differenet. Although the parameters restriction are now determined by
1283  * the same code.
1284  *
1285  * Return: Zero on success, otherwise an error number.
1286  */
1287 static int idt_ntb_peer_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
1288 				     u64 addr, resource_size_t size)
1289 {
1290 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1291 	struct idt_mw_cfg *mw_cfg;
1292 	u32 data = 0, lutoff = 0;
1293 
1294 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1295 		return -EINVAL;
1296 
1297 	if (widx < 0 || ndev->mw_cnt <= widx)
1298 		return -EINVAL;
1299 
1300 	/*
1301 	 * Retrieve the memory window config to make sure the passed arguments
1302 	 * fit it restrictions
1303 	 */
1304 	mw_cfg = &ndev->mws[widx];
1305 	if (!IS_ALIGNED(addr, mw_cfg->addr_align))
1306 		return -EINVAL;
1307 	if (!IS_ALIGNED(size, mw_cfg->size_align) || size > mw_cfg->size_max)
1308 		return -EINVAL;
1309 
1310 	/* DIR and LUT based translations are initialized differently */
1311 	if (mw_cfg->type == IDT_MW_DIR) {
1312 		const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
1313 		u64 limit;
1314 		/* Set destination partition of translation */
1315 		data = idt_nt_read(ndev, bar->setup);
1316 		data = SET_FIELD(BARSETUP_TPART, data, ndev->peers[pidx].part);
1317 		idt_nt_write(ndev, bar->setup, data);
1318 		/* Set translation base address */
1319 		idt_nt_write(ndev, bar->ltbase, (u32)addr);
1320 		idt_nt_write(ndev, bar->utbase, (u32)(addr >> 32));
1321 		/* Set the custom BAR aperture limit */
1322 		limit = pci_bus_address(ntb->pdev, mw_cfg->bar) + size;
1323 		idt_nt_write(ndev, bar->limit, (u32)limit);
1324 		if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
1325 			idt_nt_write(ndev, (bar + 1)->limit, (limit >> 32));
1326 	} else {
1327 		unsigned long irqflags;
1328 		/* Initialize corresponding LUT entry */
1329 		lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
1330 			 SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
1331 		data = SET_FIELD(LUTUDATA_PART, 0, ndev->peers[pidx].part) |
1332 			IDT_LUTUDATA_VALID;
1333 		spin_lock_irqsave(&ndev->lut_lock, irqflags);
1334 		idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
1335 		idt_nt_write(ndev, IDT_NT_LUTLDATA, (u32)addr);
1336 		idt_nt_write(ndev, IDT_NT_LUTMDATA, (u32)(addr >> 32));
1337 		idt_nt_write(ndev, IDT_NT_LUTUDATA, data);
1338 		spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
1339 		/* Limit address isn't specified since size is fixed for LUT */
1340 	}
1341 
1342 	return 0;
1343 }
1344 
1345 /*
1346  * idt_ntb_peer_mw_clear_trans() - clear the outbound MW translation address
1347  *				   (NTB API callback)
1348  * @ntb:	NTB device context.
1349  * @pidx:	Port index of peer device.
1350  * @widx:	Memory window index.
1351  *
1352  * It effectively disables the translation over the specified outbound MW.
1353  *
1354  * Return: Zero on success, otherwise an error number.
1355  */
1356 static int idt_ntb_peer_mw_clear_trans(struct ntb_dev *ntb, int pidx,
1357 					int widx)
1358 {
1359 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1360 	struct idt_mw_cfg *mw_cfg;
1361 
1362 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1363 		return -EINVAL;
1364 
1365 	if (widx < 0 || ndev->mw_cnt <= widx)
1366 		return -EINVAL;
1367 
1368 	mw_cfg = &ndev->mws[widx];
1369 
1370 	/* DIR and LUT based translations are initialized differently */
1371 	if (mw_cfg->type == IDT_MW_DIR) {
1372 		const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
1373 		u32 data;
1374 		/* Read BARSETUP to check BAR type */
1375 		data = idt_nt_read(ndev, bar->setup);
1376 		/* Disable translation by specifying zero BAR limit */
1377 		idt_nt_write(ndev, bar->limit, 0);
1378 		if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
1379 			idt_nt_write(ndev, (bar + 1)->limit, 0);
1380 	} else {
1381 		unsigned long irqflags;
1382 		u32 lutoff;
1383 		/* Clear the corresponding LUT entry up */
1384 		lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
1385 			 SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
1386 		spin_lock_irqsave(&ndev->lut_lock, irqflags);
1387 		idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
1388 		idt_nt_write(ndev, IDT_NT_LUTLDATA, 0);
1389 		idt_nt_write(ndev, IDT_NT_LUTMDATA, 0);
1390 		idt_nt_write(ndev, IDT_NT_LUTUDATA, 0);
1391 		spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
1392 	}
1393 
1394 	return 0;
1395 }
1396 
1397 /*=============================================================================
1398  *                          5. Doorbell operations
1399  *
1400  *    Doorbell functionality of IDT PCIe-switches is pretty unusual. First of
1401  * all there is global doorbell register which state can be changed by any
1402  * NT-function of the IDT device in accordance with global permissions. These
1403  * permissions configs are not supported by NTB API, so it must be done by
1404  * either BIOS or EEPROM settings. In the same way the state of the global
1405  * doorbell is reflected to the NT-functions local inbound doorbell registers.
1406  * It can lead to situations when client driver sets some peer doorbell bits
1407  * and get them bounced back to local inbound doorbell if permissions are
1408  * granted.
1409  *    Secondly there is just one IRQ vector for Doorbell, Message, Temperature
1410  * and Switch events, so if client driver left any of Doorbell bits set and
1411  * some other event occurred, the driver will be notified of Doorbell event
1412  * again.
1413  *=============================================================================
1414  */
1415 
1416 /*
1417  * idt_db_isr() - doorbell event ISR
1418  * @ndev:	IDT NTB hardware driver descriptor
1419  * @ntint_sts:	NT-function interrupt status
1420  *
1421  * Doorbell event happans when DBELL bit of NTINTSTS switches from 0 to 1.
1422  * It happens only when unmasked doorbell bits are set to ones on completely
1423  * zeroed doorbell register.
1424  * The method is called from PCIe ISR bottom-half routine.
1425  */
1426 static void idt_db_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
1427 {
1428 	/*
1429 	 * Doorbell IRQ status will be cleaned only when client
1430 	 * driver unsets all the doorbell bits.
1431 	 */
1432 	dev_dbg(&ndev->ntb.pdev->dev, "DB IRQ detected %#08x", ntint_sts);
1433 
1434 	/* Notify the client driver of possible doorbell state change */
1435 	ntb_db_event(&ndev->ntb, 0);
1436 }
1437 
1438 /*
1439  * idt_ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
1440  *			     (NTB API callback)
1441  * @ntb:	NTB device context.
1442  *
1443  * IDT PCIe-switches expose just one Doorbell register of DWORD size.
1444  *
1445  * Return: A mask of doorbell bits supported by the ntb.
1446  */
1447 static u64 idt_ntb_db_valid_mask(struct ntb_dev *ntb)
1448 {
1449 	return IDT_DBELL_MASK;
1450 }
1451 
1452 /*
1453  * idt_ntb_db_read() - read the local doorbell register (NTB API callback)
1454  * @ntb:	NTB device context.
1455  *
1456  * There is just on inbound doorbell register of each NT-function, so
1457  * this method return it value.
1458  *
1459  * Return: The bits currently set in the local doorbell register.
1460  */
1461 static u64 idt_ntb_db_read(struct ntb_dev *ntb)
1462 {
1463 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1464 
1465 	return idt_nt_read(ndev, IDT_NT_INDBELLSTS);
1466 }
1467 
1468 /*
1469  * idt_ntb_db_clear() - clear bits in the local doorbell register
1470  *			(NTB API callback)
1471  * @ntb:	NTB device context.
1472  * @db_bits:	Doorbell bits to clear.
1473  *
1474  * Clear bits of inbound doorbell register by writing ones to it.
1475  *
1476  * NOTE! Invalid bits are always considered cleared so it's not an error
1477  * to clear them over.
1478  *
1479  * Return: always zero as success.
1480  */
1481 static int idt_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
1482 {
1483 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1484 
1485 	idt_nt_write(ndev, IDT_NT_INDBELLSTS, (u32)db_bits);
1486 
1487 	return 0;
1488 }
1489 
1490 /*
1491  * idt_ntb_db_read_mask() - read the local doorbell mask (NTB API callback)
1492  * @ntb:	NTB device context.
1493  *
1494  * Each inbound doorbell bit can be masked from generating IRQ by setting
1495  * the corresponding bit in inbound doorbell mask. So this method returns
1496  * the value of the register.
1497  *
1498  * Return: The bits currently set in the local doorbell mask register.
1499  */
1500 static u64 idt_ntb_db_read_mask(struct ntb_dev *ntb)
1501 {
1502 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1503 
1504 	return idt_nt_read(ndev, IDT_NT_INDBELLMSK);
1505 }
1506 
1507 /*
1508  * idt_ntb_db_set_mask() - set bits in the local doorbell mask
1509  *			   (NTB API callback)
1510  * @ntb:	NTB device context.
1511  * @db_bits:	Doorbell mask bits to set.
1512  *
1513  * The inbound doorbell register mask value must be read, then OR'ed with
1514  * passed field and only then set back.
1515  *
1516  * Return: zero on success, negative error if invalid argument passed.
1517  */
1518 static int idt_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
1519 {
1520 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1521 
1522 	return idt_reg_set_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
1523 				IDT_DBELL_MASK, db_bits);
1524 }
1525 
1526 /*
1527  * idt_ntb_db_clear_mask() - clear bits in the local doorbell mask
1528  *			     (NTB API callback)
1529  * @ntb:	NTB device context.
1530  * @db_bits:	Doorbell bits to clear.
1531  *
1532  * The method just clears the set bits up in accordance with the passed
1533  * bitfield. IDT PCIe-switch shall generate an interrupt if there hasn't
1534  * been any unmasked bit set before current unmasking. Otherwise IRQ won't
1535  * be generated since there is only one IRQ vector for all doorbells.
1536  *
1537  * Return: always zero as success
1538  */
1539 static int idt_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
1540 {
1541 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1542 
1543 	idt_reg_clear_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
1544 			   db_bits);
1545 
1546 	return 0;
1547 }
1548 
1549 /*
1550  * idt_ntb_peer_db_set() - set bits in the peer doorbell register
1551  *			   (NTB API callback)
1552  * @ntb:	NTB device context.
1553  * @db_bits:	Doorbell bits to set.
1554  *
1555  * IDT PCIe-switches exposes local outbound doorbell register to change peer
1556  * inbound doorbell register state.
1557  *
1558  * Return: zero on success, negative error if invalid argument passed.
1559  */
1560 static int idt_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
1561 {
1562 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1563 
1564 	if (db_bits & ~(u64)IDT_DBELL_MASK)
1565 		return -EINVAL;
1566 
1567 	idt_nt_write(ndev, IDT_NT_OUTDBELLSET, (u32)db_bits);
1568 	return 0;
1569 }
1570 
1571 /*=============================================================================
1572  *                          6. Messaging operations
1573  *
1574  *    Each NT-function of IDT PCIe-switch has four inbound and four outbound
1575  * message registers. Each outbound message register can be connected to one or
1576  * even more than one peer inbound message registers by setting global
1577  * configurations. Since NTB API permits one-on-one message registers mapping
1578  * only, the driver acts in according with that restriction.
1579  *=============================================================================
1580  */
1581 
1582 /*
1583  * idt_init_msg() - initialize messaging interface
1584  * @ndev:	IDT NTB hardware driver descriptor
1585  *
1586  * Just initialize the message registers routing tables locker.
1587  */
1588 static void idt_init_msg(struct idt_ntb_dev *ndev)
1589 {
1590 	unsigned char midx;
1591 
1592 	/* Init the messages routing table lockers */
1593 	for (midx = 0; midx < IDT_MSG_CNT; midx++)
1594 		spin_lock_init(&ndev->msg_locks[midx]);
1595 
1596 	dev_dbg(&ndev->ntb.pdev->dev, "NTB Messaging initialized");
1597 }
1598 
1599 /*
1600  * idt_msg_isr() - message event ISR
1601  * @ndev:	IDT NTB hardware driver descriptor
1602  * @ntint_sts:	NT-function interrupt status
1603  *
1604  * Message event happens when MSG bit of NTINTSTS switches from 0 to 1.
1605  * It happens only when unmasked message status bits are set to ones on
1606  * completely zeroed message status register.
1607  * The method is called from PCIe ISR bottom-half routine.
1608  */
1609 static void idt_msg_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
1610 {
1611 	/*
1612 	 * Message IRQ status will be cleaned only when client
1613 	 * driver unsets all the message status bits.
1614 	 */
1615 	dev_dbg(&ndev->ntb.pdev->dev, "Message IRQ detected %#08x", ntint_sts);
1616 
1617 	/* Notify the client driver of possible message status change */
1618 	ntb_msg_event(&ndev->ntb);
1619 }
1620 
1621 /*
1622  * idt_ntb_msg_count() - get the number of message registers (NTB API callback)
1623  * @ntb:	NTB device context.
1624  *
1625  * IDT PCIe-switches support four message registers.
1626  *
1627  * Return: the number of message registers.
1628  */
1629 static int idt_ntb_msg_count(struct ntb_dev *ntb)
1630 {
1631 	return IDT_MSG_CNT;
1632 }
1633 
1634 /*
1635  * idt_ntb_msg_inbits() - get a bitfield of inbound message registers status
1636  *			  (NTB API callback)
1637  * @ntb:	NTB device context.
1638  *
1639  * NT message status register is shared between inbound and outbound message
1640  * registers status
1641  *
1642  * Return: bitfield of inbound message registers.
1643  */
1644 static u64 idt_ntb_msg_inbits(struct ntb_dev *ntb)
1645 {
1646 	return (u64)IDT_INMSG_MASK;
1647 }
1648 
1649 /*
1650  * idt_ntb_msg_outbits() - get a bitfield of outbound message registers status
1651  *			  (NTB API callback)
1652  * @ntb:	NTB device context.
1653  *
1654  * NT message status register is shared between inbound and outbound message
1655  * registers status
1656  *
1657  * Return: bitfield of outbound message registers.
1658  */
1659 static u64 idt_ntb_msg_outbits(struct ntb_dev *ntb)
1660 {
1661 	return (u64)IDT_OUTMSG_MASK;
1662 }
1663 
1664 /*
1665  * idt_ntb_msg_read_sts() - read the message registers status (NTB API callback)
1666  * @ntb:	NTB device context.
1667  *
1668  * IDT PCIe-switches expose message status registers to notify drivers of
1669  * incoming data and failures in case if peer message register isn't freed.
1670  *
1671  * Return: status bits of message registers
1672  */
1673 static u64 idt_ntb_msg_read_sts(struct ntb_dev *ntb)
1674 {
1675 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1676 
1677 	return idt_nt_read(ndev, IDT_NT_MSGSTS);
1678 }
1679 
1680 /*
1681  * idt_ntb_msg_clear_sts() - clear status bits of message registers
1682  *			     (NTB API callback)
1683  * @ntb:	NTB device context.
1684  * @sts_bits:	Status bits to clear.
1685  *
1686  * Clear bits in the status register by writing ones.
1687  *
1688  * NOTE! Invalid bits are always considered cleared so it's not an error
1689  * to clear them over.
1690  *
1691  * Return: always zero as success.
1692  */
1693 static int idt_ntb_msg_clear_sts(struct ntb_dev *ntb, u64 sts_bits)
1694 {
1695 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1696 
1697 	idt_nt_write(ndev, IDT_NT_MSGSTS, sts_bits);
1698 
1699 	return 0;
1700 }
1701 
1702 /*
1703  * idt_ntb_msg_set_mask() - set mask of message register status bits
1704  *			    (NTB API callback)
1705  * @ntb:	NTB device context.
1706  * @mask_bits:	Mask bits.
1707  *
1708  * Mask the message status bits from raising an IRQ.
1709  *
1710  * Return: zero on success, negative error if invalid argument passed.
1711  */
1712 static int idt_ntb_msg_set_mask(struct ntb_dev *ntb, u64 mask_bits)
1713 {
1714 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1715 
1716 	return idt_reg_set_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
1717 				IDT_MSG_MASK, mask_bits);
1718 }
1719 
1720 /*
1721  * idt_ntb_msg_clear_mask() - clear message registers mask
1722  *			      (NTB API callback)
1723  * @ntb:	NTB device context.
1724  * @mask_bits:	Mask bits.
1725  *
1726  * Clear mask of message status bits IRQs.
1727  *
1728  * Return: always zero as success.
1729  */
1730 static int idt_ntb_msg_clear_mask(struct ntb_dev *ntb, u64 mask_bits)
1731 {
1732 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1733 
1734 	idt_reg_clear_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
1735 			   mask_bits);
1736 
1737 	return 0;
1738 }
1739 
1740 /*
1741  * idt_ntb_msg_read() - read message register with specified index
1742  *			(NTB API callback)
1743  * @ntb:	NTB device context.
1744  * @pidx:	OUT - Port index of peer device a message retrieved from
1745  * @midx:	Message register index
1746  *
1747  * Read data from the specified message register and source register.
1748  *
1749  * Return: inbound message register value.
1750  */
1751 static u32 idt_ntb_msg_read(struct ntb_dev *ntb, int *pidx, int midx)
1752 {
1753 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1754 
1755 	if (midx < 0 || IDT_MSG_CNT <= midx)
1756 		return ~(u32)0;
1757 
1758 	/* Retrieve source port index of the message */
1759 	if (pidx != NULL) {
1760 		u32 srcpart;
1761 
1762 		srcpart = idt_nt_read(ndev, ntdata_tbl.msgs[midx].src);
1763 		*pidx = ndev->part_idx_map[srcpart];
1764 
1765 		/* Sanity check partition index (for initial case) */
1766 		if (*pidx == -EINVAL)
1767 			*pidx = 0;
1768 	}
1769 
1770 	/* Retrieve data of the corresponding message register */
1771 	return idt_nt_read(ndev, ntdata_tbl.msgs[midx].in);
1772 }
1773 
1774 /*
1775  * idt_ntb_peer_msg_write() - write data to the specified message register
1776  *			      (NTB API callback)
1777  * @ntb:	NTB device context.
1778  * @pidx:	Port index of peer device a message being sent to
1779  * @midx:	Message register index
1780  * @msg:	Data to send
1781  *
1782  * Just try to send data to a peer. Message status register should be
1783  * checked by client driver.
1784  *
1785  * Return: zero on success, negative error if invalid argument passed.
1786  */
1787 static int idt_ntb_peer_msg_write(struct ntb_dev *ntb, int pidx, int midx,
1788 				  u32 msg)
1789 {
1790 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1791 	unsigned long irqflags;
1792 	u32 swpmsgctl = 0;
1793 
1794 	if (midx < 0 || IDT_MSG_CNT <= midx)
1795 		return -EINVAL;
1796 
1797 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1798 		return -EINVAL;
1799 
1800 	/* Collect the routing information */
1801 	swpmsgctl = SET_FIELD(SWPxMSGCTL_REG, 0, midx) |
1802 		    SET_FIELD(SWPxMSGCTL_PART, 0, ndev->peers[pidx].part);
1803 
1804 	/* Lock the messages routing table of the specified register */
1805 	spin_lock_irqsave(&ndev->msg_locks[midx], irqflags);
1806 	/* Set the route and send the data */
1807 	idt_sw_write(ndev, partdata_tbl[ndev->part].msgctl[midx], swpmsgctl);
1808 	idt_nt_write(ndev, ntdata_tbl.msgs[midx].out, msg);
1809 	/* Unlock the messages routing table */
1810 	spin_unlock_irqrestore(&ndev->msg_locks[midx], irqflags);
1811 
1812 	/* Client driver shall check the status register */
1813 	return 0;
1814 }
1815 
1816 /*=============================================================================
1817  *                      7. Temperature sensor operations
1818  *
1819  *    IDT PCIe-switch has an embedded temperature sensor, which can be used to
1820  * check current chip core temperature. Since a workload environment can be
1821  * different on different platforms, an offset and ADC/filter settings can be
1822  * specified. Although the offset configuration is only exposed to the sysfs
1823  * hwmon interface at the moment. The rest of the settings can be adjusted
1824  * for instance by the BIOS/EEPROM firmware.
1825  *=============================================================================
1826  */
1827 
1828 /*
1829  * idt_get_deg() - convert millidegree Celsius value to just degree
1830  * @mdegC:	IN - millidegree Celsius value
1831  *
1832  * Return: Degree corresponding to the passed millidegree value
1833  */
1834 static inline s8 idt_get_deg(long mdegC)
1835 {
1836 	return mdegC / 1000;
1837 }
1838 
1839 /*
1840  * idt_get_frac() - retrieve 0/0.5 fraction of the millidegree Celsius value
1841  * @mdegC:	IN - millidegree Celsius value
1842  *
1843  * Return: 0/0.5 degree fraction of the passed millidegree value
1844  */
1845 static inline u8 idt_get_deg_frac(long mdegC)
1846 {
1847 	return (mdegC % 1000) >= 500 ? 5 : 0;
1848 }
1849 
1850 /*
1851  * idt_get_temp_fmt() - convert millidegree Celsius value to 0:7:1 format
1852  * @mdegC:	IN - millidegree Celsius value
1853  *
1854  * Return: 0:7:1 format acceptable by the IDT temperature sensor
1855  */
1856 static inline u8 idt_temp_get_fmt(long mdegC)
1857 {
1858 	return (idt_get_deg(mdegC) << 1) | (idt_get_deg_frac(mdegC) ? 1 : 0);
1859 }
1860 
1861 /*
1862  * idt_get_temp_sval() - convert temp sample to signed millidegree Celsius
1863  * @data:	IN - shifted to LSB 8-bits temperature sample
1864  *
1865  * Return: signed millidegree Celsius
1866  */
1867 static inline long idt_get_temp_sval(u32 data)
1868 {
1869 	return ((s8)data / 2) * 1000 + (data & 0x1 ? 500 : 0);
1870 }
1871 
1872 /*
1873  * idt_get_temp_sval() - convert temp sample to unsigned millidegree Celsius
1874  * @data:	IN - shifted to LSB 8-bits temperature sample
1875  *
1876  * Return: unsigned millidegree Celsius
1877  */
1878 static inline long idt_get_temp_uval(u32 data)
1879 {
1880 	return (data / 2) * 1000 + (data & 0x1 ? 500 : 0);
1881 }
1882 
1883 /*
1884  * idt_read_temp() - read temperature from chip sensor
1885  * @ntb:	NTB device context.
1886  * @type:	IN - type of the temperature value to read
1887  * @val:	OUT - integer value of temperature in millidegree Celsius
1888  */
1889 static void idt_read_temp(struct idt_ntb_dev *ndev,
1890 			  const enum idt_temp_val type, long *val)
1891 {
1892 	u32 data;
1893 
1894 	/* Alter the temperature field in accordance with the passed type */
1895 	switch (type) {
1896 	case IDT_TEMP_CUR:
1897 		data = GET_FIELD(TMPSTS_TEMP,
1898 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1899 		break;
1900 	case IDT_TEMP_LOW:
1901 		data = GET_FIELD(TMPSTS_LTEMP,
1902 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1903 		break;
1904 	case IDT_TEMP_HIGH:
1905 		data = GET_FIELD(TMPSTS_HTEMP,
1906 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1907 		break;
1908 	case IDT_TEMP_OFFSET:
1909 		/* This is the only field with signed 0:7:1 format */
1910 		data = GET_FIELD(TMPADJ_OFFSET,
1911 				 idt_sw_read(ndev, IDT_SW_TMPADJ));
1912 		*val = idt_get_temp_sval(data);
1913 		return;
1914 	default:
1915 		data = GET_FIELD(TMPSTS_TEMP,
1916 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1917 		break;
1918 	}
1919 
1920 	/* The rest of the fields accept unsigned 0:7:1 format */
1921 	*val = idt_get_temp_uval(data);
1922 }
1923 
1924 /*
1925  * idt_write_temp() - write temperature to the chip sensor register
1926  * @ntb:	NTB device context.
1927  * @type:	IN - type of the temperature value to change
1928  * @val:	IN - integer value of temperature in millidegree Celsius
1929  */
1930 static void idt_write_temp(struct idt_ntb_dev *ndev,
1931 			   const enum idt_temp_val type, const long val)
1932 {
1933 	unsigned int reg;
1934 	u32 data;
1935 	u8 fmt;
1936 
1937 	/* Retrieve the properly formatted temperature value */
1938 	fmt = idt_temp_get_fmt(val);
1939 
1940 	mutex_lock(&ndev->hwmon_mtx);
1941 	switch (type) {
1942 	case IDT_TEMP_LOW:
1943 		reg = IDT_SW_TMPALARM;
1944 		data = SET_FIELD(TMPALARM_LTEMP, idt_sw_read(ndev, reg), fmt) &
1945 			~IDT_TMPALARM_IRQ_MASK;
1946 		break;
1947 	case IDT_TEMP_HIGH:
1948 		reg = IDT_SW_TMPALARM;
1949 		data = SET_FIELD(TMPALARM_HTEMP, idt_sw_read(ndev, reg), fmt) &
1950 			~IDT_TMPALARM_IRQ_MASK;
1951 		break;
1952 	case IDT_TEMP_OFFSET:
1953 		reg = IDT_SW_TMPADJ;
1954 		data = SET_FIELD(TMPADJ_OFFSET, idt_sw_read(ndev, reg), fmt);
1955 		break;
1956 	default:
1957 		goto inval_spin_unlock;
1958 	}
1959 
1960 	idt_sw_write(ndev, reg, data);
1961 
1962 inval_spin_unlock:
1963 	mutex_unlock(&ndev->hwmon_mtx);
1964 }
1965 
1966 /*
1967  * idt_sysfs_show_temp() - printout corresponding temperature value
1968  * @dev:	Pointer to the NTB device structure
1969  * @da:		Sensor device attribute structure
1970  * @buf:	Buffer to print temperature out
1971  *
1972  * Return: Number of written symbols or negative error
1973  */
1974 static ssize_t idt_sysfs_show_temp(struct device *dev,
1975 				   struct device_attribute *da, char *buf)
1976 {
1977 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
1978 	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
1979 	enum idt_temp_val type = attr->index;
1980 	long mdeg;
1981 
1982 	idt_read_temp(ndev, type, &mdeg);
1983 	return sprintf(buf, "%ld\n", mdeg);
1984 }
1985 
1986 /*
1987  * idt_sysfs_set_temp() - set corresponding temperature value
1988  * @dev:	Pointer to the NTB device structure
1989  * @da:		Sensor device attribute structure
1990  * @buf:	Buffer to print temperature out
1991  * @count:	Size of the passed buffer
1992  *
1993  * Return: Number of written symbols or negative error
1994  */
1995 static ssize_t idt_sysfs_set_temp(struct device *dev,
1996 				  struct device_attribute *da, const char *buf,
1997 				  size_t count)
1998 {
1999 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
2000 	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
2001 	enum idt_temp_val type = attr->index;
2002 	long mdeg;
2003 	int ret;
2004 
2005 	ret = kstrtol(buf, 10, &mdeg);
2006 	if (ret)
2007 		return ret;
2008 
2009 	/* Clamp the passed value in accordance with the type */
2010 	if (type == IDT_TEMP_OFFSET)
2011 		mdeg = clamp_val(mdeg, IDT_TEMP_MIN_OFFSET,
2012 				 IDT_TEMP_MAX_OFFSET);
2013 	else
2014 		mdeg = clamp_val(mdeg, IDT_TEMP_MIN_MDEG, IDT_TEMP_MAX_MDEG);
2015 
2016 	idt_write_temp(ndev, type, mdeg);
2017 
2018 	return count;
2019 }
2020 
2021 /*
2022  * idt_sysfs_reset_hist() - reset temperature history
2023  * @dev:	Pointer to the NTB device structure
2024  * @da:		Sensor device attribute structure
2025  * @buf:	Buffer to print temperature out
2026  * @count:	Size of the passed buffer
2027  *
2028  * Return: Number of written symbols or negative error
2029  */
2030 static ssize_t idt_sysfs_reset_hist(struct device *dev,
2031 				    struct device_attribute *da,
2032 				    const char *buf, size_t count)
2033 {
2034 	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
2035 
2036 	/* Just set the maximal value to the lowest temperature field and
2037 	 * minimal value to the highest temperature field
2038 	 */
2039 	idt_write_temp(ndev, IDT_TEMP_LOW, IDT_TEMP_MAX_MDEG);
2040 	idt_write_temp(ndev, IDT_TEMP_HIGH, IDT_TEMP_MIN_MDEG);
2041 
2042 	return count;
2043 }
2044 
2045 /*
2046  * Hwmon IDT sysfs attributes
2047  */
2048 static SENSOR_DEVICE_ATTR(temp1_input, 0444, idt_sysfs_show_temp, NULL,
2049 			  IDT_TEMP_CUR);
2050 static SENSOR_DEVICE_ATTR(temp1_lowest, 0444, idt_sysfs_show_temp, NULL,
2051 			  IDT_TEMP_LOW);
2052 static SENSOR_DEVICE_ATTR(temp1_highest, 0444, idt_sysfs_show_temp, NULL,
2053 			  IDT_TEMP_HIGH);
2054 static SENSOR_DEVICE_ATTR(temp1_offset, 0644, idt_sysfs_show_temp,
2055 			  idt_sysfs_set_temp, IDT_TEMP_OFFSET);
2056 static DEVICE_ATTR(temp1_reset_history, 0200, NULL, idt_sysfs_reset_hist);
2057 
2058 /*
2059  * Hwmon IDT sysfs attributes group
2060  */
2061 static struct attribute *idt_temp_attrs[] = {
2062 	&sensor_dev_attr_temp1_input.dev_attr.attr,
2063 	&sensor_dev_attr_temp1_lowest.dev_attr.attr,
2064 	&sensor_dev_attr_temp1_highest.dev_attr.attr,
2065 	&sensor_dev_attr_temp1_offset.dev_attr.attr,
2066 	&dev_attr_temp1_reset_history.attr,
2067 	NULL
2068 };
2069 ATTRIBUTE_GROUPS(idt_temp);
2070 
2071 /*
2072  * idt_init_temp() - initialize temperature sensor interface
2073  * @ndev:	IDT NTB hardware driver descriptor
2074  *
2075  * Simple sensor initializarion method is responsible for device switching
2076  * on and resource management based hwmon interface registration. Note, that
2077  * since the device is shared we won't disable it on remove, but leave it
2078  * working until the system is powered off.
2079  */
2080 static void idt_init_temp(struct idt_ntb_dev *ndev)
2081 {
2082 	struct device *hwmon;
2083 
2084 	/* Enable sensor if it hasn't been already */
2085 	idt_sw_write(ndev, IDT_SW_TMPCTL, 0x0);
2086 
2087 	/* Initialize hwmon interface fields */
2088 	mutex_init(&ndev->hwmon_mtx);
2089 
2090 	hwmon = devm_hwmon_device_register_with_groups(&ndev->ntb.pdev->dev,
2091 		ndev->swcfg->name, ndev, idt_temp_groups);
2092 	if (IS_ERR(hwmon)) {
2093 		dev_err(&ndev->ntb.pdev->dev, "Couldn't create hwmon device");
2094 		return;
2095 	}
2096 
2097 	dev_dbg(&ndev->ntb.pdev->dev, "Temperature HWmon interface registered");
2098 }
2099 
2100 /*=============================================================================
2101  *                           8. ISRs related operations
2102  *
2103  *    IDT PCIe-switch has strangely developed IRQ system. There is just one
2104  * interrupt vector for doorbell and message registers. So the hardware driver
2105  * can't determine actual source of IRQ if, for example, message event happened
2106  * while any of unmasked doorbell is still set. The similar situation may be if
2107  * switch or temperature sensor events pop up. The difference is that SEVENT
2108  * and TMPSENSOR bits of NT interrupt status register can be cleaned by
2109  * IRQ handler so a next interrupt request won't have false handling of
2110  * corresponding events.
2111  *    The hardware driver has only bottom-half handler of the IRQ, since if any
2112  * of events happened the device won't raise it again before the last one is
2113  * handled by clearing of corresponding NTINTSTS bit.
2114  *=============================================================================
2115  */
2116 
2117 static irqreturn_t idt_thread_isr(int irq, void *devid);
2118 
2119 /*
2120  * idt_init_isr() - initialize PCIe interrupt handler
2121  * @ndev:	IDT NTB hardware driver descriptor
2122  *
2123  * Return: zero on success, otherwise a negative error number.
2124  */
2125 static int idt_init_isr(struct idt_ntb_dev *ndev)
2126 {
2127 	struct pci_dev *pdev = ndev->ntb.pdev;
2128 	u32 ntint_mask;
2129 	int ret;
2130 
2131 	/* Allocate just one interrupt vector for the ISR */
2132 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI | PCI_IRQ_LEGACY);
2133 	if (ret != 1) {
2134 		dev_err(&pdev->dev, "Failed to allocate IRQ vector");
2135 		return ret;
2136 	}
2137 
2138 	/* Retrieve the IRQ vector */
2139 	ret = pci_irq_vector(pdev, 0);
2140 	if (ret < 0) {
2141 		dev_err(&pdev->dev, "Failed to get IRQ vector");
2142 		goto err_free_vectors;
2143 	}
2144 
2145 	/* Set the IRQ handler */
2146 	ret = devm_request_threaded_irq(&pdev->dev, ret, NULL, idt_thread_isr,
2147 					IRQF_ONESHOT, NTB_IRQNAME, ndev);
2148 	if (ret != 0) {
2149 		dev_err(&pdev->dev, "Failed to set MSI IRQ handler, %d", ret);
2150 		goto err_free_vectors;
2151 	}
2152 
2153 	/* Unmask Message/Doorbell/SE interrupts */
2154 	ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) & ~IDT_NTINTMSK_ALL;
2155 	idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
2156 
2157 	/* From now on the interrupts are enabled */
2158 	dev_dbg(&pdev->dev, "NTB interrupts initialized");
2159 
2160 	return 0;
2161 
2162 err_free_vectors:
2163 	pci_free_irq_vectors(pdev);
2164 
2165 	return ret;
2166 }
2167 
2168 /*
2169  * idt_deinit_ist() - deinitialize PCIe interrupt handler
2170  * @ndev:	IDT NTB hardware driver descriptor
2171  *
2172  * Disable corresponding interrupts and free allocated IRQ vectors.
2173  */
2174 static void idt_deinit_isr(struct idt_ntb_dev *ndev)
2175 {
2176 	struct pci_dev *pdev = ndev->ntb.pdev;
2177 	u32 ntint_mask;
2178 
2179 	/* Mask interrupts back */
2180 	ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) | IDT_NTINTMSK_ALL;
2181 	idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
2182 
2183 	/* Manually free IRQ otherwise PCI free irq vectors will fail */
2184 	devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 0), ndev);
2185 
2186 	/* Free allocated IRQ vectors */
2187 	pci_free_irq_vectors(pdev);
2188 
2189 	dev_dbg(&pdev->dev, "NTB interrupts deinitialized");
2190 }
2191 
2192 /*
2193  * idt_thread_isr() - NT function interrupts handler
2194  * @irq:	IRQ number
2195  * @devid:	Custom buffer
2196  *
2197  * It reads current NT interrupts state register and handles all the event
2198  * it declares.
2199  * The method is bottom-half routine of actual default PCIe IRQ handler.
2200  */
2201 static irqreturn_t idt_thread_isr(int irq, void *devid)
2202 {
2203 	struct idt_ntb_dev *ndev = devid;
2204 	bool handled = false;
2205 	u32 ntint_sts;
2206 
2207 	/* Read the NT interrupts status register */
2208 	ntint_sts = idt_nt_read(ndev, IDT_NT_NTINTSTS);
2209 
2210 	/* Handle messaging interrupts */
2211 	if (ntint_sts & IDT_NTINTSTS_MSG) {
2212 		idt_msg_isr(ndev, ntint_sts);
2213 		handled = true;
2214 	}
2215 
2216 	/* Handle doorbell interrupts */
2217 	if (ntint_sts & IDT_NTINTSTS_DBELL) {
2218 		idt_db_isr(ndev, ntint_sts);
2219 		handled = true;
2220 	}
2221 
2222 	/* Handle switch event interrupts */
2223 	if (ntint_sts & IDT_NTINTSTS_SEVENT) {
2224 		idt_se_isr(ndev, ntint_sts);
2225 		handled = true;
2226 	}
2227 
2228 	dev_dbg(&ndev->ntb.pdev->dev, "IDT IRQs 0x%08x handled", ntint_sts);
2229 
2230 	return handled ? IRQ_HANDLED : IRQ_NONE;
2231 }
2232 
2233 /*===========================================================================
2234  *                     9. NTB hardware driver initialization
2235  *===========================================================================
2236  */
2237 
2238 /*
2239  * NTB API operations
2240  */
2241 static const struct ntb_dev_ops idt_ntb_ops = {
2242 	.port_number		= idt_ntb_port_number,
2243 	.peer_port_count	= idt_ntb_peer_port_count,
2244 	.peer_port_number	= idt_ntb_peer_port_number,
2245 	.peer_port_idx		= idt_ntb_peer_port_idx,
2246 	.link_is_up		= idt_ntb_link_is_up,
2247 	.link_enable		= idt_ntb_link_enable,
2248 	.link_disable		= idt_ntb_link_disable,
2249 	.mw_count		= idt_ntb_mw_count,
2250 	.mw_get_align		= idt_ntb_mw_get_align,
2251 	.peer_mw_count		= idt_ntb_peer_mw_count,
2252 	.peer_mw_get_addr	= idt_ntb_peer_mw_get_addr,
2253 	.peer_mw_set_trans	= idt_ntb_peer_mw_set_trans,
2254 	.peer_mw_clear_trans	= idt_ntb_peer_mw_clear_trans,
2255 	.db_valid_mask		= idt_ntb_db_valid_mask,
2256 	.db_read		= idt_ntb_db_read,
2257 	.db_clear		= idt_ntb_db_clear,
2258 	.db_read_mask		= idt_ntb_db_read_mask,
2259 	.db_set_mask		= idt_ntb_db_set_mask,
2260 	.db_clear_mask		= idt_ntb_db_clear_mask,
2261 	.peer_db_set		= idt_ntb_peer_db_set,
2262 	.msg_count		= idt_ntb_msg_count,
2263 	.msg_inbits		= idt_ntb_msg_inbits,
2264 	.msg_outbits		= idt_ntb_msg_outbits,
2265 	.msg_read_sts		= idt_ntb_msg_read_sts,
2266 	.msg_clear_sts		= idt_ntb_msg_clear_sts,
2267 	.msg_set_mask		= idt_ntb_msg_set_mask,
2268 	.msg_clear_mask		= idt_ntb_msg_clear_mask,
2269 	.msg_read		= idt_ntb_msg_read,
2270 	.peer_msg_write		= idt_ntb_peer_msg_write
2271 };
2272 
2273 /*
2274  * idt_register_device() - register IDT NTB device
2275  * @ndev:	IDT NTB hardware driver descriptor
2276  *
2277  * Return: zero on success, otherwise a negative error number.
2278  */
2279 static int idt_register_device(struct idt_ntb_dev *ndev)
2280 {
2281 	int ret;
2282 
2283 	/* Initialize the rest of NTB device structure and register it */
2284 	ndev->ntb.ops = &idt_ntb_ops;
2285 	ndev->ntb.topo = NTB_TOPO_SWITCH;
2286 
2287 	ret = ntb_register_device(&ndev->ntb);
2288 	if (ret != 0) {
2289 		dev_err(&ndev->ntb.pdev->dev, "Failed to register NTB device");
2290 		return ret;
2291 	}
2292 
2293 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device successfully registered");
2294 
2295 	return 0;
2296 }
2297 
2298 /*
2299  * idt_unregister_device() - unregister IDT NTB device
2300  * @ndev:	IDT NTB hardware driver descriptor
2301  */
2302 static void idt_unregister_device(struct idt_ntb_dev *ndev)
2303 {
2304 	/* Just unregister the NTB device */
2305 	ntb_unregister_device(&ndev->ntb);
2306 
2307 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device unregistered");
2308 }
2309 
2310 /*=============================================================================
2311  *                        10. DebugFS node initialization
2312  *=============================================================================
2313  */
2314 
2315 static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
2316 				   size_t count, loff_t *offp);
2317 
2318 /*
2319  * Driver DebugFS info file operations
2320  */
2321 static const struct file_operations idt_dbgfs_info_ops = {
2322 	.owner = THIS_MODULE,
2323 	.open = simple_open,
2324 	.read = idt_dbgfs_info_read
2325 };
2326 
2327 /*
2328  * idt_dbgfs_info_read() - DebugFS read info node callback
2329  * @file:	File node descriptor.
2330  * @ubuf:	User-space buffer to put data to
2331  * @count:	Size of the buffer
2332  * @offp:	Offset within the buffer
2333  */
2334 static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
2335 				   size_t count, loff_t *offp)
2336 {
2337 	struct idt_ntb_dev *ndev = filp->private_data;
2338 	unsigned char idx, pidx, cnt;
2339 	unsigned long irqflags, mdeg;
2340 	ssize_t ret = 0, off = 0;
2341 	enum ntb_speed speed;
2342 	enum ntb_width width;
2343 	char *strbuf;
2344 	size_t size;
2345 	u32 data;
2346 
2347 	/* Lets limit the buffer size the way the Intel/AMD drivers do */
2348 	size = min_t(size_t, count, 0x1000U);
2349 
2350 	/* Allocate the memory for the buffer */
2351 	strbuf = kmalloc(size, GFP_KERNEL);
2352 	if (strbuf == NULL)
2353 		return -ENOMEM;
2354 
2355 	/* Put the data into the string buffer */
2356 	off += scnprintf(strbuf + off, size - off,
2357 		"\n\t\tIDT NTB device Information:\n\n");
2358 
2359 	/* General local device configurations */
2360 	off += scnprintf(strbuf + off, size - off,
2361 		"Local Port %hhu, Partition %hhu\n", ndev->port, ndev->part);
2362 
2363 	/* Peer ports information */
2364 	off += scnprintf(strbuf + off, size - off, "Peers:\n");
2365 	for (idx = 0; idx < ndev->peer_cnt; idx++) {
2366 		off += scnprintf(strbuf + off, size - off,
2367 			"\t%hhu. Port %hhu, Partition %hhu\n",
2368 			idx, ndev->peers[idx].port, ndev->peers[idx].part);
2369 	}
2370 
2371 	/* Links status */
2372 	data = idt_ntb_link_is_up(&ndev->ntb, &speed, &width);
2373 	off += scnprintf(strbuf + off, size - off,
2374 		"NTB link status\t- 0x%08x, ", data);
2375 	off += scnprintf(strbuf + off, size - off, "PCIe Gen %d x%d lanes\n",
2376 		speed, width);
2377 
2378 	/* Mapping table entries */
2379 	off += scnprintf(strbuf + off, size - off, "NTB Mapping Table:\n");
2380 	for (idx = 0; idx < IDT_MTBL_ENTRY_CNT; idx++) {
2381 		spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
2382 		idt_nt_write(ndev, IDT_NT_NTMTBLADDR, idx);
2383 		data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
2384 		spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
2385 
2386 		/* Print valid entries only */
2387 		if (data & IDT_NTMTBLDATA_VALID) {
2388 			off += scnprintf(strbuf + off, size - off,
2389 				"\t%hhu. Partition %d, Requester ID 0x%04x\n",
2390 				idx, GET_FIELD(NTMTBLDATA_PART, data),
2391 				GET_FIELD(NTMTBLDATA_REQID, data));
2392 		}
2393 	}
2394 	off += scnprintf(strbuf + off, size - off, "\n");
2395 
2396 	/* Outbound memory windows information */
2397 	off += scnprintf(strbuf + off, size - off,
2398 		"Outbound Memory Windows:\n");
2399 	for (idx = 0; idx < ndev->mw_cnt; idx += cnt) {
2400 		data = ndev->mws[idx].type;
2401 		cnt = idt_get_mw_count(data);
2402 
2403 		/* Print Memory Window information */
2404 		if (data == IDT_MW_DIR)
2405 			off += scnprintf(strbuf + off, size - off,
2406 				"\t%hhu.\t", idx);
2407 		else
2408 			off += scnprintf(strbuf + off, size - off,
2409 				"\t%hhu-%d.\t", idx, idx + cnt - 1);
2410 
2411 		off += scnprintf(strbuf + off, size - off, "%s BAR%hhu, ",
2412 			idt_get_mw_name(data), ndev->mws[idx].bar);
2413 
2414 		off += scnprintf(strbuf + off, size - off,
2415 			"Address align 0x%08llx, ", ndev->mws[idx].addr_align);
2416 
2417 		off += scnprintf(strbuf + off, size - off,
2418 			"Size align 0x%08llx, Size max %llu\n",
2419 			ndev->mws[idx].size_align, ndev->mws[idx].size_max);
2420 	}
2421 
2422 	/* Inbound memory windows information */
2423 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
2424 		off += scnprintf(strbuf + off, size - off,
2425 			"Inbound Memory Windows for peer %hhu (Port %hhu):\n",
2426 			pidx, ndev->peers[pidx].port);
2427 
2428 		/* Print Memory Windows information */
2429 		for (idx = 0; idx < ndev->peers[pidx].mw_cnt; idx += cnt) {
2430 			data = ndev->peers[pidx].mws[idx].type;
2431 			cnt = idt_get_mw_count(data);
2432 
2433 			if (data == IDT_MW_DIR)
2434 				off += scnprintf(strbuf + off, size - off,
2435 					"\t%hhu.\t", idx);
2436 			else
2437 				off += scnprintf(strbuf + off, size - off,
2438 					"\t%hhu-%d.\t", idx, idx + cnt - 1);
2439 
2440 			off += scnprintf(strbuf + off, size - off,
2441 				"%s BAR%hhu, ", idt_get_mw_name(data),
2442 				ndev->peers[pidx].mws[idx].bar);
2443 
2444 			off += scnprintf(strbuf + off, size - off,
2445 				"Address align 0x%08llx, ",
2446 				ndev->peers[pidx].mws[idx].addr_align);
2447 
2448 			off += scnprintf(strbuf + off, size - off,
2449 				"Size align 0x%08llx, Size max %llu\n",
2450 				ndev->peers[pidx].mws[idx].size_align,
2451 				ndev->peers[pidx].mws[idx].size_max);
2452 		}
2453 	}
2454 	off += scnprintf(strbuf + off, size - off, "\n");
2455 
2456 	/* Doorbell information */
2457 	data = idt_sw_read(ndev, IDT_SW_GDBELLSTS);
2458 	off += scnprintf(strbuf + off, size - off,
2459 		 "Global Doorbell state\t- 0x%08x\n", data);
2460 	data = idt_ntb_db_read(&ndev->ntb);
2461 	off += scnprintf(strbuf + off, size - off,
2462 		 "Local  Doorbell state\t- 0x%08x\n", data);
2463 	data = idt_nt_read(ndev, IDT_NT_INDBELLMSK);
2464 	off += scnprintf(strbuf + off, size - off,
2465 		 "Local  Doorbell mask\t- 0x%08x\n", data);
2466 	off += scnprintf(strbuf + off, size - off, "\n");
2467 
2468 	/* Messaging information */
2469 	off += scnprintf(strbuf + off, size - off,
2470 		 "Message event valid\t- 0x%08x\n", IDT_MSG_MASK);
2471 	data = idt_ntb_msg_read_sts(&ndev->ntb);
2472 	off += scnprintf(strbuf + off, size - off,
2473 		 "Message event status\t- 0x%08x\n", data);
2474 	data = idt_nt_read(ndev, IDT_NT_MSGSTSMSK);
2475 	off += scnprintf(strbuf + off, size - off,
2476 		 "Message event mask\t- 0x%08x\n", data);
2477 	off += scnprintf(strbuf + off, size - off,
2478 		 "Message data:\n");
2479 	for (idx = 0; idx < IDT_MSG_CNT; idx++) {
2480 		int src;
2481 		data = idt_ntb_msg_read(&ndev->ntb, &src, idx);
2482 		off += scnprintf(strbuf + off, size - off,
2483 			"\t%hhu. 0x%08x from peer %d (Port %hhu)\n",
2484 			idx, data, src, ndev->peers[src].port);
2485 	}
2486 	off += scnprintf(strbuf + off, size - off, "\n");
2487 
2488 	/* Current temperature */
2489 	idt_read_temp(ndev, IDT_TEMP_CUR, &mdeg);
2490 	off += scnprintf(strbuf + off, size - off,
2491 		"Switch temperature\t\t- %hhd.%hhuC\n",
2492 		idt_get_deg(mdeg), idt_get_deg_frac(mdeg));
2493 
2494 	/* Copy the buffer to the User Space */
2495 	ret = simple_read_from_buffer(ubuf, count, offp, strbuf, off);
2496 	kfree(strbuf);
2497 
2498 	return ret;
2499 }
2500 
2501 /*
2502  * idt_init_dbgfs() - initialize DebugFS node
2503  * @ndev:	IDT NTB hardware driver descriptor
2504  *
2505  * Return: zero on success, otherwise a negative error number.
2506  */
2507 static int idt_init_dbgfs(struct idt_ntb_dev *ndev)
2508 {
2509 	char devname[64];
2510 
2511 	/* If the top directory is not created then do nothing */
2512 	if (IS_ERR_OR_NULL(dbgfs_topdir)) {
2513 		dev_info(&ndev->ntb.pdev->dev, "Top DebugFS directory absent");
2514 		return PTR_ERR_OR_ZERO(dbgfs_topdir);
2515 	}
2516 
2517 	/* Create the info file node */
2518 	snprintf(devname, 64, "info:%s", pci_name(ndev->ntb.pdev));
2519 	ndev->dbgfs_info = debugfs_create_file(devname, 0400, dbgfs_topdir,
2520 		ndev, &idt_dbgfs_info_ops);
2521 	if (IS_ERR(ndev->dbgfs_info)) {
2522 		dev_dbg(&ndev->ntb.pdev->dev, "Failed to create DebugFS node");
2523 		return PTR_ERR(ndev->dbgfs_info);
2524 	}
2525 
2526 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node created");
2527 
2528 	return 0;
2529 }
2530 
2531 /*
2532  * idt_deinit_dbgfs() - deinitialize DebugFS node
2533  * @ndev:	IDT NTB hardware driver descriptor
2534  *
2535  * Just discard the info node from DebugFS
2536  */
2537 static void idt_deinit_dbgfs(struct idt_ntb_dev *ndev)
2538 {
2539 	debugfs_remove(ndev->dbgfs_info);
2540 
2541 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node discarded");
2542 }
2543 
2544 /*=============================================================================
2545  *                     11. Basic PCIe device initialization
2546  *=============================================================================
2547  */
2548 
2549 /*
2550  * idt_check_setup() - Check whether the IDT PCIe-swtich is properly
2551  *		       pre-initialized
2552  * @pdev:	Pointer to the PCI device descriptor
2553  *
2554  * Return: zero on success, otherwise a negative error number.
2555  */
2556 static int idt_check_setup(struct pci_dev *pdev)
2557 {
2558 	u32 data;
2559 	int ret;
2560 
2561 	/* Read the BARSETUP0 */
2562 	ret = pci_read_config_dword(pdev, IDT_NT_BARSETUP0, &data);
2563 	if (ret != 0) {
2564 		dev_err(&pdev->dev,
2565 			"Failed to read BARSETUP0 config register");
2566 		return ret;
2567 	}
2568 
2569 	/* Check whether the BAR0 register is enabled to be of config space */
2570 	if (!(data & IDT_BARSETUP_EN) || !(data & IDT_BARSETUP_MODE_CFG)) {
2571 		dev_err(&pdev->dev, "BAR0 doesn't map config space");
2572 		return -EINVAL;
2573 	}
2574 
2575 	/* Configuration space BAR0 must have certain size */
2576 	if ((data & IDT_BARSETUP_SIZE_MASK) != IDT_BARSETUP_SIZE_CFG) {
2577 		dev_err(&pdev->dev, "Invalid size of config space");
2578 		return -EINVAL;
2579 	}
2580 
2581 	dev_dbg(&pdev->dev, "NTB device pre-initialized correctly");
2582 
2583 	return 0;
2584 }
2585 
2586 /*
2587  * Create the IDT PCIe-switch driver descriptor
2588  * @pdev:	Pointer to the PCI device descriptor
2589  * @id:		IDT PCIe-device configuration
2590  *
2591  * It just allocates a memory for IDT PCIe-switch device structure and
2592  * initializes some commonly used fields.
2593  *
2594  * No need of release method, since managed device resource is used for
2595  * memory allocation.
2596  *
2597  * Return: pointer to the descriptor, otherwise a negative error number.
2598  */
2599 static struct idt_ntb_dev *idt_create_dev(struct pci_dev *pdev,
2600 					  const struct pci_device_id *id)
2601 {
2602 	struct idt_ntb_dev *ndev;
2603 
2604 	/* Allocate memory for the IDT PCIe-device descriptor */
2605 	ndev = devm_kzalloc(&pdev->dev, sizeof(*ndev), GFP_KERNEL);
2606 	if (!ndev) {
2607 		dev_err(&pdev->dev, "Memory allocation failed for descriptor");
2608 		return ERR_PTR(-ENOMEM);
2609 	}
2610 
2611 	/* Save the IDT PCIe-switch ports configuration */
2612 	ndev->swcfg = (struct idt_89hpes_cfg *)id->driver_data;
2613 	/* Save the PCI-device pointer inside the NTB device structure */
2614 	ndev->ntb.pdev = pdev;
2615 
2616 	/* Initialize spin locker of Doorbell, Message and GASA registers */
2617 	spin_lock_init(&ndev->db_mask_lock);
2618 	spin_lock_init(&ndev->msg_mask_lock);
2619 	spin_lock_init(&ndev->gasa_lock);
2620 
2621 	dev_info(&pdev->dev, "IDT %s discovered", ndev->swcfg->name);
2622 
2623 	dev_dbg(&pdev->dev, "NTB device descriptor created");
2624 
2625 	return ndev;
2626 }
2627 
2628 /*
2629  * idt_init_pci() - initialize the basic PCI-related subsystem
2630  * @ndev:	Pointer to the IDT PCIe-switch driver descriptor
2631  *
2632  * Managed device resources will be freed automatically in case of failure or
2633  * driver detachment.
2634  *
2635  * Return: zero on success, otherwise negative error number.
2636  */
2637 static int idt_init_pci(struct idt_ntb_dev *ndev)
2638 {
2639 	struct pci_dev *pdev = ndev->ntb.pdev;
2640 	int ret;
2641 
2642 	/* Initialize the bit mask of PCI/NTB DMA */
2643 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
2644 	if (ret != 0) {
2645 		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
2646 		if (ret != 0) {
2647 			dev_err(&pdev->dev, "Failed to set DMA bit mask\n");
2648 			return ret;
2649 		}
2650 		dev_warn(&pdev->dev, "Cannot set DMA highmem bit mask\n");
2651 	}
2652 
2653 	/*
2654 	 * The PCI core enables device error reporting. It's not critical to
2655 	 * have AER disabled in the kernel.
2656 	 *
2657 	 * Cleanup nonfatal error status before getting to init.
2658 	 */
2659 	pci_aer_clear_nonfatal_status(pdev);
2660 
2661 	/* First enable the PCI device */
2662 	ret = pcim_enable_device(pdev);
2663 	if (ret != 0) {
2664 		dev_err(&pdev->dev, "Failed to enable PCIe device\n");
2665 		return ret;
2666 	}
2667 
2668 	/*
2669 	 * Enable the bus mastering, which effectively enables MSI IRQs and
2670 	 * Request TLPs translation
2671 	 */
2672 	pci_set_master(pdev);
2673 
2674 	/* Request all BARs resources and map BAR0 only */
2675 	ret = pcim_iomap_regions_request_all(pdev, 1, NTB_NAME);
2676 	if (ret != 0) {
2677 		dev_err(&pdev->dev, "Failed to request resources\n");
2678 		goto err_clear_master;
2679 	}
2680 
2681 	/* Retrieve virtual address of BAR0 - PCI configuration space */
2682 	ndev->cfgspc = pcim_iomap_table(pdev)[0];
2683 
2684 	/* Put the IDT driver data pointer to the PCI-device private pointer */
2685 	pci_set_drvdata(pdev, ndev);
2686 
2687 	dev_dbg(&pdev->dev, "NT-function PCIe interface initialized");
2688 
2689 	return 0;
2690 
2691 err_clear_master:
2692 	pci_clear_master(pdev);
2693 
2694 	return ret;
2695 }
2696 
2697 /*
2698  * idt_deinit_pci() - deinitialize the basic PCI-related subsystem
2699  * @ndev:	Pointer to the IDT PCIe-switch driver descriptor
2700  *
2701  * Managed resources will be freed on the driver detachment
2702  */
2703 static void idt_deinit_pci(struct idt_ntb_dev *ndev)
2704 {
2705 	struct pci_dev *pdev = ndev->ntb.pdev;
2706 
2707 	/* Clean up the PCI-device private data pointer */
2708 	pci_set_drvdata(pdev, NULL);
2709 
2710 	/* Clear the bus master disabling the Request TLPs translation */
2711 	pci_clear_master(pdev);
2712 
2713 	dev_dbg(&pdev->dev, "NT-function PCIe interface cleared");
2714 }
2715 
2716 /*===========================================================================
2717  *                       12. PCI bus callback functions
2718  *===========================================================================
2719  */
2720 
2721 /*
2722  * idt_pci_probe() - PCI device probe callback
2723  * @pdev:	Pointer to PCI device structure
2724  * @id:		PCIe device custom descriptor
2725  *
2726  * Return: zero on success, otherwise negative error number
2727  */
2728 static int idt_pci_probe(struct pci_dev *pdev,
2729 			 const struct pci_device_id *id)
2730 {
2731 	struct idt_ntb_dev *ndev;
2732 	int ret;
2733 
2734 	/* Check whether IDT PCIe-switch is properly pre-initialized */
2735 	ret = idt_check_setup(pdev);
2736 	if (ret != 0)
2737 		return ret;
2738 
2739 	/* Allocate the memory for IDT NTB device data */
2740 	ndev = idt_create_dev(pdev, id);
2741 	if (IS_ERR(ndev))
2742 		return PTR_ERR(ndev);
2743 
2744 	/* Initialize the basic PCI subsystem of the device */
2745 	ret = idt_init_pci(ndev);
2746 	if (ret != 0)
2747 		return ret;
2748 
2749 	/* Scan ports of the IDT PCIe-switch */
2750 	(void)idt_scan_ports(ndev);
2751 
2752 	/* Initialize NTB link events subsystem */
2753 	idt_init_link(ndev);
2754 
2755 	/* Initialize MWs subsystem */
2756 	ret = idt_init_mws(ndev);
2757 	if (ret != 0)
2758 		goto err_deinit_link;
2759 
2760 	/* Initialize Messaging subsystem */
2761 	idt_init_msg(ndev);
2762 
2763 	/* Initialize hwmon interface */
2764 	idt_init_temp(ndev);
2765 
2766 	/* Initialize IDT interrupts handler */
2767 	ret = idt_init_isr(ndev);
2768 	if (ret != 0)
2769 		goto err_deinit_link;
2770 
2771 	/* Register IDT NTB devices on the NTB bus */
2772 	ret = idt_register_device(ndev);
2773 	if (ret != 0)
2774 		goto err_deinit_isr;
2775 
2776 	/* Initialize DebugFS info node */
2777 	(void)idt_init_dbgfs(ndev);
2778 
2779 	/* IDT PCIe-switch NTB driver is finally initialized */
2780 	dev_info(&pdev->dev, "IDT NTB device is ready");
2781 
2782 	/* May the force be with us... */
2783 	return 0;
2784 
2785 err_deinit_isr:
2786 	idt_deinit_isr(ndev);
2787 err_deinit_link:
2788 	idt_deinit_link(ndev);
2789 	idt_deinit_pci(ndev);
2790 
2791 	return ret;
2792 }
2793 
2794 /*
2795  * idt_pci_probe() - PCI device remove callback
2796  * @pdev:	Pointer to PCI device structure
2797  */
2798 static void idt_pci_remove(struct pci_dev *pdev)
2799 {
2800 	struct idt_ntb_dev *ndev = pci_get_drvdata(pdev);
2801 
2802 	/* Deinit the DebugFS node */
2803 	idt_deinit_dbgfs(ndev);
2804 
2805 	/* Unregister NTB device */
2806 	idt_unregister_device(ndev);
2807 
2808 	/* Stop the interrupts handling */
2809 	idt_deinit_isr(ndev);
2810 
2811 	/* Deinitialize link event subsystem */
2812 	idt_deinit_link(ndev);
2813 
2814 	/* Deinit basic PCI subsystem */
2815 	idt_deinit_pci(ndev);
2816 
2817 	/* IDT PCIe-switch NTB driver is finally initialized */
2818 	dev_info(&pdev->dev, "IDT NTB device is removed");
2819 
2820 	/* Sayonara... */
2821 }
2822 
2823 /*
2824  * IDT PCIe-switch models ports configuration structures
2825  */
2826 static const struct idt_89hpes_cfg idt_89hpes24nt6ag2_config = {
2827 	.name = "89HPES24NT6AG2",
2828 	.port_cnt = 6, .ports = {0, 2, 4, 6, 8, 12}
2829 };
2830 static const struct idt_89hpes_cfg idt_89hpes32nt8ag2_config = {
2831 	.name = "89HPES32NT8AG2",
2832 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2833 };
2834 static const struct idt_89hpes_cfg idt_89hpes32nt8bg2_config = {
2835 	.name = "89HPES32NT8BG2",
2836 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2837 };
2838 static const struct idt_89hpes_cfg idt_89hpes12nt12g2_config = {
2839 	.name = "89HPES12NT12G2",
2840 	.port_cnt = 3, .ports = {0, 8, 16}
2841 };
2842 static const struct idt_89hpes_cfg idt_89hpes16nt16g2_config = {
2843 	.name = "89HPES16NT16G2",
2844 	.port_cnt = 4, .ports = {0, 8, 12, 16}
2845 };
2846 static const struct idt_89hpes_cfg idt_89hpes24nt24g2_config = {
2847 	.name = "89HPES24NT24G2",
2848 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2849 };
2850 static const struct idt_89hpes_cfg idt_89hpes32nt24ag2_config = {
2851 	.name = "89HPES32NT24AG2",
2852 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2853 };
2854 static const struct idt_89hpes_cfg idt_89hpes32nt24bg2_config = {
2855 	.name = "89HPES32NT24BG2",
2856 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2857 };
2858 
2859 /*
2860  * PCI-ids table of the supported IDT PCIe-switch devices
2861  */
2862 static const struct pci_device_id idt_pci_tbl[] = {
2863 	{IDT_PCI_DEVICE_IDS(89HPES24NT6AG2,  idt_89hpes24nt6ag2_config)},
2864 	{IDT_PCI_DEVICE_IDS(89HPES32NT8AG2,  idt_89hpes32nt8ag2_config)},
2865 	{IDT_PCI_DEVICE_IDS(89HPES32NT8BG2,  idt_89hpes32nt8bg2_config)},
2866 	{IDT_PCI_DEVICE_IDS(89HPES12NT12G2,  idt_89hpes12nt12g2_config)},
2867 	{IDT_PCI_DEVICE_IDS(89HPES16NT16G2,  idt_89hpes16nt16g2_config)},
2868 	{IDT_PCI_DEVICE_IDS(89HPES24NT24G2,  idt_89hpes24nt24g2_config)},
2869 	{IDT_PCI_DEVICE_IDS(89HPES32NT24AG2, idt_89hpes32nt24ag2_config)},
2870 	{IDT_PCI_DEVICE_IDS(89HPES32NT24BG2, idt_89hpes32nt24bg2_config)},
2871 	{0}
2872 };
2873 MODULE_DEVICE_TABLE(pci, idt_pci_tbl);
2874 
2875 /*
2876  * IDT PCIe-switch NT-function device driver structure definition
2877  */
2878 static struct pci_driver idt_pci_driver = {
2879 	.name		= KBUILD_MODNAME,
2880 	.probe		= idt_pci_probe,
2881 	.remove		= idt_pci_remove,
2882 	.id_table	= idt_pci_tbl,
2883 };
2884 
2885 static int __init idt_pci_driver_init(void)
2886 {
2887 	int ret;
2888 	pr_info("%s %s\n", NTB_DESC, NTB_VER);
2889 
2890 	/* Create the top DebugFS directory if the FS is initialized */
2891 	if (debugfs_initialized())
2892 		dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2893 
2894 	/* Register the NTB hardware driver to handle the PCI device */
2895 	ret = pci_register_driver(&idt_pci_driver);
2896 	if (ret)
2897 		debugfs_remove_recursive(dbgfs_topdir);
2898 
2899 	return ret;
2900 }
2901 module_init(idt_pci_driver_init);
2902 
2903 static void __exit idt_pci_driver_exit(void)
2904 {
2905 	/* Unregister the NTB hardware driver */
2906 	pci_unregister_driver(&idt_pci_driver);
2907 
2908 	/* Discard the top DebugFS directory */
2909 	debugfs_remove_recursive(dbgfs_topdir);
2910 }
2911 module_exit(idt_pci_driver_exit);
2912 
2913