xref: /openbmc/linux/drivers/ntb/hw/idt/ntb_hw_idt.c (revision 5d331b7f)
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 	/* Make sure the PCIe transactions are executed */
362 	mmiowb();
363 	/* Unlock GASA registers operations */
364 	spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
365 }
366 
367 /*
368  * idt_sw_read() - Global registers read method
369  * @ndev:	IDT NTB hardware driver descriptor
370  * @reg:	Register to write data to
371  *
372  * IDT PCIe-switch Global configuration registers are all Little endian.
373  *
374  * Return: register value
375  */
376 static u32 idt_sw_read(struct idt_ntb_dev *ndev, const unsigned int reg)
377 {
378 	unsigned long irqflags;
379 	u32 data;
380 
381 	/*
382 	 * It's obvious bug to request a register exceeding the maximum possible
383 	 * value as well as to have it unaligned.
384 	 */
385 	if (WARN_ON(reg > IDT_REG_SW_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
386 		return ~0;
387 
388 	/* Lock GASA registers operations */
389 	spin_lock_irqsave(&ndev->gasa_lock, irqflags);
390 	/* Set the global register address */
391 	iowrite32((u32)reg, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASAADDR);
392 	/* Get the data of the register (read ops acts as MMIO barrier) */
393 	data = ioread32(ndev->cfgspc + (ptrdiff_t)IDT_NT_GASADATA);
394 	/* Unlock GASA registers operations */
395 	spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
396 
397 	return data;
398 }
399 
400 /*
401  * idt_reg_set_bits() - set bits of a passed register
402  * @ndev:	IDT NTB hardware driver descriptor
403  * @reg:	Register to change bits of
404  * @reg_lock:	Register access spin lock
405  * @valid_mask:	Mask of valid bits
406  * @set_bits:	Bitmask to set
407  *
408  * Helper method to check whether a passed bitfield is valid and set
409  * corresponding bits of a register.
410  *
411  * WARNING! Make sure the passed register isn't accessed over plane
412  * idt_nt_write() method (read method is ok to be used concurrently).
413  *
414  * Return: zero on success, negative error on invalid bitmask.
415  */
416 static inline int idt_reg_set_bits(struct idt_ntb_dev *ndev, unsigned int reg,
417 				   spinlock_t *reg_lock,
418 				   u64 valid_mask, u64 set_bits)
419 {
420 	unsigned long irqflags;
421 	u32 data;
422 
423 	if (set_bits & ~(u64)valid_mask)
424 		return -EINVAL;
425 
426 	/* Lock access to the register unless the change is written back */
427 	spin_lock_irqsave(reg_lock, irqflags);
428 	data = idt_nt_read(ndev, reg) | (u32)set_bits;
429 	idt_nt_write(ndev, reg, data);
430 	/* Unlock the register */
431 	spin_unlock_irqrestore(reg_lock, irqflags);
432 
433 	return 0;
434 }
435 
436 /*
437  * idt_reg_clear_bits() - clear bits of a passed register
438  * @ndev:	IDT NTB hardware driver descriptor
439  * @reg:	Register to change bits of
440  * @reg_lock:	Register access spin lock
441  * @set_bits:	Bitmask to clear
442  *
443  * Helper method to check whether a passed bitfield is valid and clear
444  * corresponding bits of a register.
445  *
446  * NOTE! Invalid bits are always considered cleared so it's not an error
447  * to clear them over.
448  *
449  * WARNING! Make sure the passed register isn't accessed over plane
450  * idt_nt_write() method (read method is ok to use concurrently).
451  */
452 static inline void idt_reg_clear_bits(struct idt_ntb_dev *ndev,
453 				     unsigned int reg, spinlock_t *reg_lock,
454 				     u64 clear_bits)
455 {
456 	unsigned long irqflags;
457 	u32 data;
458 
459 	/* Lock access to the register unless the change is written back */
460 	spin_lock_irqsave(reg_lock, irqflags);
461 	data = idt_nt_read(ndev, reg) & ~(u32)clear_bits;
462 	idt_nt_write(ndev, reg, data);
463 	/* Unlock the register */
464 	spin_unlock_irqrestore(reg_lock, irqflags);
465 }
466 
467 /*===========================================================================
468  *                           2. Ports operations
469  *
470  *    IDT PCIe-switches can have from 3 up to 8 ports with possible
471  * NT-functions enabled. So all the possible ports need to be scanned looking
472  * for NTB activated. NTB API will have enumerated only the ports with NTB.
473  *===========================================================================
474  */
475 
476 /*
477  * idt_scan_ports() - scan IDT PCIe-switch ports collecting info in the tables
478  * @ndev:	Pointer to the PCI device descriptor
479  *
480  * Return: zero on success, otherwise a negative error number.
481  */
482 static int idt_scan_ports(struct idt_ntb_dev *ndev)
483 {
484 	unsigned char pidx, port, part;
485 	u32 data, portsts, partsts;
486 
487 	/* Retrieve the local port number */
488 	data = idt_nt_read(ndev, IDT_NT_PCIELCAP);
489 	ndev->port = GET_FIELD(PCIELCAP_PORTNUM, data);
490 
491 	/* Retrieve the local partition number */
492 	portsts = idt_sw_read(ndev, portdata_tbl[ndev->port].sts);
493 	ndev->part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
494 
495 	/* Initialize port/partition -> index tables with invalid values */
496 	memset(ndev->port_idx_map, -EINVAL, sizeof(ndev->port_idx_map));
497 	memset(ndev->part_idx_map, -EINVAL, sizeof(ndev->part_idx_map));
498 
499 	/*
500 	 * Walk over all the possible ports checking whether any of them has
501 	 * NT-function activated
502 	 */
503 	ndev->peer_cnt = 0;
504 	for (pidx = 0; pidx < ndev->swcfg->port_cnt; pidx++) {
505 		port = ndev->swcfg->ports[pidx];
506 		/* Skip local port */
507 		if (port == ndev->port)
508 			continue;
509 
510 		/* Read the port status register to get it partition */
511 		portsts = idt_sw_read(ndev, portdata_tbl[port].sts);
512 		part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
513 
514 		/* Retrieve the partition status */
515 		partsts = idt_sw_read(ndev, partdata_tbl[part].sts);
516 		/* Check if partition state is active and port has NTB */
517 		if (IS_FLD_SET(SWPARTxSTS_STATE, partsts, ACT) &&
518 		    (IS_FLD_SET(SWPORTxSTS_MODE, portsts, NT) ||
519 		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNT) ||
520 		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNTDMA) ||
521 		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, NTDMA))) {
522 			/* Save the port and partition numbers */
523 			ndev->peers[ndev->peer_cnt].port = port;
524 			ndev->peers[ndev->peer_cnt].part = part;
525 			/* Fill in the port/partition -> index tables */
526 			ndev->port_idx_map[port] = ndev->peer_cnt;
527 			ndev->part_idx_map[part] = ndev->peer_cnt;
528 			ndev->peer_cnt++;
529 		}
530 	}
531 
532 	dev_dbg(&ndev->ntb.pdev->dev, "Local port: %hhu, num of peers: %hhu\n",
533 		ndev->port, ndev->peer_cnt);
534 
535 	/* It's useless to have this driver loaded if there is no any peer */
536 	if (ndev->peer_cnt == 0) {
537 		dev_warn(&ndev->ntb.pdev->dev, "No active peer found\n");
538 		return -ENODEV;
539 	}
540 
541 	return 0;
542 }
543 
544 /*
545  * idt_ntb_port_number() - get the local port number
546  * @ntb:	NTB device context.
547  *
548  * Return: the local port number
549  */
550 static int idt_ntb_port_number(struct ntb_dev *ntb)
551 {
552 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
553 
554 	return ndev->port;
555 }
556 
557 /*
558  * idt_ntb_peer_port_count() - get the number of peer ports
559  * @ntb:	NTB device context.
560  *
561  * Return the count of detected peer NT-functions.
562  *
563  * Return: number of peer ports
564  */
565 static int idt_ntb_peer_port_count(struct ntb_dev *ntb)
566 {
567 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
568 
569 	return ndev->peer_cnt;
570 }
571 
572 /*
573  * idt_ntb_peer_port_number() - get peer port by given index
574  * @ntb:	NTB device context.
575  * @pidx:	Peer port index.
576  *
577  * Return: peer port or negative error
578  */
579 static int idt_ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
580 {
581 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
582 
583 	if (pidx < 0 || ndev->peer_cnt <= pidx)
584 		return -EINVAL;
585 
586 	/* Return the detected NT-function port number */
587 	return ndev->peers[pidx].port;
588 }
589 
590 /*
591  * idt_ntb_peer_port_idx() - get peer port index by given port number
592  * @ntb:	NTB device context.
593  * @port:	Peer port number.
594  *
595  * Internal port -> index table is pre-initialized with -EINVAL values,
596  * so we just need to return it value
597  *
598  * Return: peer NT-function port index or negative error
599  */
600 static int idt_ntb_peer_port_idx(struct ntb_dev *ntb, int port)
601 {
602 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
603 
604 	if (port < 0 || IDT_MAX_NR_PORTS <= port)
605 		return -EINVAL;
606 
607 	return ndev->port_idx_map[port];
608 }
609 
610 /*===========================================================================
611  *                         3. Link status operations
612  *    There is no any ready-to-use method to have peer ports notified if NTB
613  * link is set up or got down. Instead global signal can be used instead.
614  * In case if any one of ports changes local NTB link state, it sends
615  * global signal and clears corresponding global state bit. Then all the ports
616  * receive a notification of that, so to make client driver being aware of
617  * possible NTB link change.
618  *    Additionally each of active NT-functions is subscribed to PCIe-link
619  * state changes of peer ports.
620  *===========================================================================
621  */
622 
623 static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev);
624 
625 /*
626  * idt_init_link() - Initialize NTB link state notification subsystem
627  * @ndev:	IDT NTB hardware driver descriptor
628  *
629  * Function performs the basic initialization of some global registers
630  * needed to enable IRQ-based notifications of PCIe Link Up/Down and
631  * Global Signal events.
632  * NOTE Since it's not possible to determine when all the NTB peer drivers are
633  * unloaded as well as have those registers accessed concurrently, we must
634  * preinitialize them with the same value and leave it uncleared on local
635  * driver unload.
636  */
637 static void idt_init_link(struct idt_ntb_dev *ndev)
638 {
639 	u32 part_mask, port_mask, se_mask;
640 	unsigned char pidx;
641 
642 	/* Initialize spin locker of Mapping Table access registers */
643 	spin_lock_init(&ndev->mtbl_lock);
644 
645 	/* Walk over all detected peers collecting port and partition masks */
646 	port_mask = ~BIT(ndev->port);
647 	part_mask = ~BIT(ndev->part);
648 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
649 		port_mask &= ~BIT(ndev->peers[pidx].port);
650 		part_mask &= ~BIT(ndev->peers[pidx].part);
651 	}
652 
653 	/* Clean the Link Up/Down and GLobal Signal status registers */
654 	idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
655 	idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
656 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
657 
658 	/* Unmask NT-activated partitions to receive Global Switch events */
659 	idt_sw_write(ndev, IDT_SW_SEPMSK, part_mask);
660 
661 	/* Enable PCIe Link Up events of NT-activated ports */
662 	idt_sw_write(ndev, IDT_SW_SELINKUPMSK, port_mask);
663 
664 	/* Enable PCIe Link Down events of NT-activated ports */
665 	idt_sw_write(ndev, IDT_SW_SELINKDNMSK, port_mask);
666 
667 	/* Unmask NT-activated partitions to receive Global Signal events */
668 	idt_sw_write(ndev, IDT_SW_SEGSIGMSK, part_mask);
669 
670 	/* Unmask Link Up/Down and Global Switch Events */
671 	se_mask = ~(IDT_SEMSK_LINKUP | IDT_SEMSK_LINKDN | IDT_SEMSK_GSIGNAL);
672 	idt_sw_write(ndev, IDT_SW_SEMSK, se_mask);
673 
674 	dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events initialized");
675 }
676 
677 /*
678  * idt_deinit_link() - deinitialize link subsystem
679  * @ndev:	IDT NTB hardware driver descriptor
680  *
681  * Just disable the link back.
682  */
683 static void idt_deinit_link(struct idt_ntb_dev *ndev)
684 {
685 	/* Disable the link */
686 	idt_ntb_local_link_disable(ndev);
687 
688 	dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events deinitialized");
689 }
690 
691 /*
692  * idt_se_isr() - switch events ISR
693  * @ndev:	IDT NTB hardware driver descriptor
694  * @ntint_sts:	NT-function interrupt status
695  *
696  * This driver doesn't support IDT PCIe-switch dynamic reconfigurations,
697  * Failover capability, etc, so switch events are utilized to notify of
698  * PCIe and NTB link events.
699  * The method is called from PCIe ISR bottom-half routine.
700  */
701 static void idt_se_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
702 {
703 	u32 sests;
704 
705 	/* Read Switch Events status */
706 	sests = idt_sw_read(ndev, IDT_SW_SESTS);
707 
708 	/* Clean the Link Up/Down and Global Signal status registers */
709 	idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
710 	idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
711 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
712 
713 	/* Clean the corresponding interrupt bit */
714 	idt_nt_write(ndev, IDT_NT_NTINTSTS, IDT_NTINTSTS_SEVENT);
715 
716 	dev_dbg(&ndev->ntb.pdev->dev, "SE IRQ detected %#08x (SESTS %#08x)",
717 			  ntint_sts, sests);
718 
719 	/* Notify the client driver of possible link state change */
720 	ntb_link_event(&ndev->ntb);
721 }
722 
723 /*
724  * idt_ntb_local_link_enable() - enable the local NTB link.
725  * @ndev:	IDT NTB hardware driver descriptor
726  *
727  * In order to enable the NTB link we need:
728  * - enable Completion TLPs translation
729  * - initialize mapping table to enable the Request ID translation
730  * - notify peers of NTB link state change
731  */
732 static void idt_ntb_local_link_enable(struct idt_ntb_dev *ndev)
733 {
734 	u32 reqid, mtbldata = 0;
735 	unsigned long irqflags;
736 
737 	/* Enable the ID protection and Completion TLPs translation */
738 	idt_nt_write(ndev, IDT_NT_NTCTL, IDT_NTCTL_CPEN);
739 
740 	/* Retrieve the current Requester ID (Bus:Device:Function) */
741 	reqid = idt_nt_read(ndev, IDT_NT_REQIDCAP);
742 
743 	/*
744 	 * Set the corresponding NT Mapping table entry of port partition index
745 	 * with the data to perform the Request ID translation
746 	 */
747 	mtbldata = SET_FIELD(NTMTBLDATA_REQID, 0, reqid) |
748 		   SET_FIELD(NTMTBLDATA_PART, 0, ndev->part) |
749 		   IDT_NTMTBLDATA_VALID;
750 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
751 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
752 	idt_nt_write(ndev, IDT_NT_NTMTBLDATA, mtbldata);
753 	mmiowb();
754 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
755 
756 	/* Notify the peers by setting and clearing the global signal bit */
757 	idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
758 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
759 }
760 
761 /*
762  * idt_ntb_local_link_disable() - disable the local NTB link.
763  * @ndev:	IDT NTB hardware driver descriptor
764  *
765  * In order to enable the NTB link we need:
766  * - disable Completion TLPs translation
767  * - clear corresponding mapping table entry
768  * - notify peers of NTB link state change
769  */
770 static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev)
771 {
772 	unsigned long irqflags;
773 
774 	/* Disable Completion TLPs translation */
775 	idt_nt_write(ndev, IDT_NT_NTCTL, 0);
776 
777 	/* Clear the corresponding NT Mapping table entry */
778 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
779 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
780 	idt_nt_write(ndev, IDT_NT_NTMTBLDATA, 0);
781 	mmiowb();
782 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
783 
784 	/* Notify the peers by setting and clearing the global signal bit */
785 	idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
786 	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
787 }
788 
789 /*
790  * idt_ntb_local_link_is_up() - test wethter local NTB link is up
791  * @ndev:	IDT NTB hardware driver descriptor
792  *
793  * Local link is up under the following conditions:
794  * - Bus mastering is enabled
795  * - NTCTL has Completion TLPs translation enabled
796  * - Mapping table permits Request TLPs translation
797  * NOTE: We don't need to check PCIe link state since it's obviously
798  * up while we are able to communicate with IDT PCIe-switch
799  *
800  * Return: true if link is up, otherwise false
801  */
802 static bool idt_ntb_local_link_is_up(struct idt_ntb_dev *ndev)
803 {
804 	unsigned long irqflags;
805 	u32 data;
806 
807 	/* Read the local Bus Master Enable status */
808 	data = idt_nt_read(ndev, IDT_NT_PCICMDSTS);
809 	if (!(data & IDT_PCICMDSTS_BME))
810 		return false;
811 
812 	/* Read the local Completion TLPs translation enable status */
813 	data = idt_nt_read(ndev, IDT_NT_NTCTL);
814 	if (!(data & IDT_NTCTL_CPEN))
815 		return false;
816 
817 	/* Read Mapping table entry corresponding to the local partition */
818 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
819 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
820 	data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
821 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
822 
823 	return !!(data & IDT_NTMTBLDATA_VALID);
824 }
825 
826 /*
827  * idt_ntb_peer_link_is_up() - test whether peer NTB link is up
828  * @ndev:	IDT NTB hardware driver descriptor
829  * @pidx:	Peer port index
830  *
831  * Peer link is up under the following conditions:
832  * - PCIe link is up
833  * - Bus mastering is enabled
834  * - NTCTL has Completion TLPs translation enabled
835  * - Mapping table permits Request TLPs translation
836  *
837  * Return: true if link is up, otherwise false
838  */
839 static bool idt_ntb_peer_link_is_up(struct idt_ntb_dev *ndev, int pidx)
840 {
841 	unsigned long irqflags;
842 	unsigned char port;
843 	u32 data;
844 
845 	/* Retrieve the device port number */
846 	port = ndev->peers[pidx].port;
847 
848 	/* Check whether PCIe link is up */
849 	data = idt_sw_read(ndev, portdata_tbl[port].sts);
850 	if (!(data & IDT_SWPORTxSTS_LINKUP))
851 		return false;
852 
853 	/* Check whether bus mastering is enabled on the peer port */
854 	data = idt_sw_read(ndev, portdata_tbl[port].pcicmdsts);
855 	if (!(data & IDT_PCICMDSTS_BME))
856 		return false;
857 
858 	/* Check if Completion TLPs translation is enabled on the peer port */
859 	data = idt_sw_read(ndev, portdata_tbl[port].ntctl);
860 	if (!(data & IDT_NTCTL_CPEN))
861 		return false;
862 
863 	/* Read Mapping table entry corresponding to the peer partition */
864 	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
865 	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->peers[pidx].part);
866 	data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
867 	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
868 
869 	return !!(data & IDT_NTMTBLDATA_VALID);
870 }
871 
872 /*
873  * idt_ntb_link_is_up() - get the current ntb link state (NTB API callback)
874  * @ntb:	NTB device context.
875  * @speed:	OUT - The link speed expressed as PCIe generation number.
876  * @width:	OUT - The link width expressed as the number of PCIe lanes.
877  *
878  * Get the bitfield of NTB link states for all peer ports
879  *
880  * Return: bitfield of indexed ports link state: bit is set/cleared if the
881  *         link is up/down respectively.
882  */
883 static u64 idt_ntb_link_is_up(struct ntb_dev *ntb,
884 			      enum ntb_speed *speed, enum ntb_width *width)
885 {
886 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
887 	unsigned char pidx;
888 	u64 status;
889 	u32 data;
890 
891 	/* Retrieve the local link speed and width */
892 	if (speed != NULL || width != NULL) {
893 		data = idt_nt_read(ndev, IDT_NT_PCIELCTLSTS);
894 		if (speed != NULL)
895 			*speed = GET_FIELD(PCIELCTLSTS_CLS, data);
896 		if (width != NULL)
897 			*width = GET_FIELD(PCIELCTLSTS_NLW, data);
898 	}
899 
900 	/* If local NTB link isn't up then all the links are considered down */
901 	if (!idt_ntb_local_link_is_up(ndev))
902 		return 0;
903 
904 	/* Collect all the peer ports link states into the bitfield */
905 	status = 0;
906 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
907 		if (idt_ntb_peer_link_is_up(ndev, pidx))
908 			status |= ((u64)1 << pidx);
909 	}
910 
911 	return status;
912 }
913 
914 /*
915  * idt_ntb_link_enable() - enable local port ntb link (NTB API callback)
916  * @ntb:	NTB device context.
917  * @max_speed:	The maximum link speed expressed as PCIe generation number.
918  * @max_width:	The maximum link width expressed as the number of PCIe lanes.
919  *
920  * Enable just local NTB link. PCIe link parameters are ignored.
921  *
922  * Return: always zero.
923  */
924 static int idt_ntb_link_enable(struct ntb_dev *ntb, enum ntb_speed speed,
925 			       enum ntb_width width)
926 {
927 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
928 
929 	/* Just enable the local NTB link */
930 	idt_ntb_local_link_enable(ndev);
931 
932 	dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link enabled");
933 
934 	return 0;
935 }
936 
937 /*
938  * idt_ntb_link_disable() - disable local port ntb link (NTB API callback)
939  * @ntb:	NTB device context.
940  *
941  * Disable just local NTB link.
942  *
943  * Return: always zero.
944  */
945 static int idt_ntb_link_disable(struct ntb_dev *ntb)
946 {
947 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
948 
949 	/* Just disable the local NTB link */
950 	idt_ntb_local_link_disable(ndev);
951 
952 	dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link disabled");
953 
954 	return 0;
955 }
956 
957 /*=============================================================================
958  *                         4. Memory Window operations
959  *
960  *    IDT PCIe-switches have two types of memory windows: MWs with direct
961  * address translation and MWs with LUT based translation. The first type of
962  * MWs is simple map of corresponding BAR address space to a memory space
963  * of specified target port. So it implemets just ont-to-one mapping. Lookup
964  * table in its turn can map one BAR address space to up to 24 different
965  * memory spaces of different ports.
966  *    NT-functions BARs can be turned on to implement either direct or lookup
967  * table based address translations, so:
968  * BAR0 - NT configuration registers space/direct address translation
969  * BAR1 - direct address translation/upper address of BAR0x64
970  * BAR2 - direct address translation/Lookup table with either 12 or 24 entries
971  * BAR3 - direct address translation/upper address of BAR2x64
972  * BAR4 - direct address translation/Lookup table with either 12 or 24 entries
973  * BAR5 - direct address translation/upper address of BAR4x64
974  *    Additionally BAR2 and BAR4 can't have 24-entries LUT enabled at the same
975  * time. Since the BARs setup can be rather complicated this driver implements
976  * a scanning algorithm to have all the possible memory windows configuration
977  * covered.
978  *
979  * NOTE 1 BAR setup must be done before Linux kernel enumerated NT-function
980  * of any port, so this driver would have memory windows configurations fixed.
981  * In this way all initializations must be performed either by platform BIOS
982  * or using EEPROM connected to IDT PCIe-switch master SMBus.
983  *
984  * NOTE 2 This driver expects BAR0 mapping NT-function configuration space.
985  * Easy calculation can give us an upper boundary of 29 possible memory windows
986  * per each NT-function if all the BARs are of 32bit type.
987  *=============================================================================
988  */
989 
990 /*
991  * idt_get_mw_count() - get memory window count
992  * @mw_type:	Memory window type
993  *
994  * Return: number of memory windows with respect to the BAR type
995  */
996 static inline unsigned char idt_get_mw_count(enum idt_mw_type mw_type)
997 {
998 	switch (mw_type) {
999 	case IDT_MW_DIR:
1000 		return 1;
1001 	case IDT_MW_LUT12:
1002 		return 12;
1003 	case IDT_MW_LUT24:
1004 		return 24;
1005 	default:
1006 		break;
1007 	}
1008 
1009 	return 0;
1010 }
1011 
1012 /*
1013  * idt_get_mw_name() - get memory window name
1014  * @mw_type:	Memory window type
1015  *
1016  * Return: pointer to a string with name
1017  */
1018 static inline char *idt_get_mw_name(enum idt_mw_type mw_type)
1019 {
1020 	switch (mw_type) {
1021 	case IDT_MW_DIR:
1022 		return "DIR  ";
1023 	case IDT_MW_LUT12:
1024 		return "LUT12";
1025 	case IDT_MW_LUT24:
1026 		return "LUT24";
1027 	default:
1028 		break;
1029 	}
1030 
1031 	return "unknown";
1032 }
1033 
1034 /*
1035  * idt_scan_mws() - scan memory windows of the port
1036  * @ndev:	IDT NTB hardware driver descriptor
1037  * @port:	Port to get number of memory windows for
1038  * @mw_cnt:	Out - number of memory windows
1039  *
1040  * It walks over BAR setup registers of the specified port and determines
1041  * the memory windows parameters if any activated.
1042  *
1043  * Return: array of memory windows
1044  */
1045 static struct idt_mw_cfg *idt_scan_mws(struct idt_ntb_dev *ndev, int port,
1046 				       unsigned char *mw_cnt)
1047 {
1048 	struct idt_mw_cfg mws[IDT_MAX_NR_MWS], *ret_mws;
1049 	const struct idt_ntb_bar *bars;
1050 	enum idt_mw_type mw_type;
1051 	unsigned char widx, bidx, en_cnt;
1052 	bool bar_64bit = false;
1053 	int aprt_size;
1054 	u32 data;
1055 
1056 	/* Retrieve the array of the BARs registers */
1057 	bars = portdata_tbl[port].bars;
1058 
1059 	/* Scan all the BARs belonging to the port */
1060 	*mw_cnt = 0;
1061 	for (bidx = 0; bidx < IDT_BAR_CNT; bidx += 1 + bar_64bit) {
1062 		/* Read BARSETUP register value */
1063 		data = idt_sw_read(ndev, bars[bidx].setup);
1064 
1065 		/* Skip disabled BARs */
1066 		if (!(data & IDT_BARSETUP_EN)) {
1067 			bar_64bit = false;
1068 			continue;
1069 		}
1070 
1071 		/* Skip next BARSETUP if current one has 64bit addressing */
1072 		bar_64bit = IS_FLD_SET(BARSETUP_TYPE, data, 64);
1073 
1074 		/* Skip configuration space mapping BARs */
1075 		if (data & IDT_BARSETUP_MODE_CFG)
1076 			continue;
1077 
1078 		/* Retrieve MW type/entries count and aperture size */
1079 		mw_type = GET_FIELD(BARSETUP_ATRAN, data);
1080 		en_cnt = idt_get_mw_count(mw_type);
1081 		aprt_size = (u64)1 << GET_FIELD(BARSETUP_SIZE, data);
1082 
1083 		/* Save configurations of all available memory windows */
1084 		for (widx = 0; widx < en_cnt; widx++, (*mw_cnt)++) {
1085 			/*
1086 			 * IDT can expose a limited number of MWs, so it's bug
1087 			 * to have more than the driver expects
1088 			 */
1089 			if (*mw_cnt >= IDT_MAX_NR_MWS)
1090 				return ERR_PTR(-EINVAL);
1091 
1092 			/* Save basic MW info */
1093 			mws[*mw_cnt].type = mw_type;
1094 			mws[*mw_cnt].bar = bidx;
1095 			mws[*mw_cnt].idx = widx;
1096 			/* It's always DWORD aligned */
1097 			mws[*mw_cnt].addr_align = IDT_TRANS_ALIGN;
1098 			/* DIR and LUT approachs differently configure MWs */
1099 			if (mw_type == IDT_MW_DIR)
1100 				mws[*mw_cnt].size_max = aprt_size;
1101 			else if (mw_type == IDT_MW_LUT12)
1102 				mws[*mw_cnt].size_max = aprt_size / 16;
1103 			else
1104 				mws[*mw_cnt].size_max = aprt_size / 32;
1105 			mws[*mw_cnt].size_align = (mw_type == IDT_MW_DIR) ?
1106 				IDT_DIR_SIZE_ALIGN : mws[*mw_cnt].size_max;
1107 		}
1108 	}
1109 
1110 	/* Allocate memory for memory window descriptors */
1111 	ret_mws = devm_kcalloc(&ndev->ntb.pdev->dev, *mw_cnt, sizeof(*ret_mws),
1112 			       GFP_KERNEL);
1113 	if (!ret_mws)
1114 		return ERR_PTR(-ENOMEM);
1115 
1116 	/* Copy the info of detected memory windows */
1117 	memcpy(ret_mws, mws, (*mw_cnt)*sizeof(*ret_mws));
1118 
1119 	return ret_mws;
1120 }
1121 
1122 /*
1123  * idt_init_mws() - initialize memory windows subsystem
1124  * @ndev:	IDT NTB hardware driver descriptor
1125  *
1126  * Scan BAR setup registers of local and peer ports to determine the
1127  * outbound and inbound memory windows parameters
1128  *
1129  * Return: zero on success, otherwise a negative error number
1130  */
1131 static int idt_init_mws(struct idt_ntb_dev *ndev)
1132 {
1133 	struct idt_ntb_peer *peer;
1134 	unsigned char pidx;
1135 
1136 	/* Scan memory windows of the local port */
1137 	ndev->mws = idt_scan_mws(ndev, ndev->port, &ndev->mw_cnt);
1138 	if (IS_ERR(ndev->mws)) {
1139 		dev_err(&ndev->ntb.pdev->dev,
1140 			"Failed to scan mws of local port %hhu", ndev->port);
1141 		return PTR_ERR(ndev->mws);
1142 	}
1143 
1144 	/* Scan memory windows of the peer ports */
1145 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
1146 		peer = &ndev->peers[pidx];
1147 		peer->mws = idt_scan_mws(ndev, peer->port, &peer->mw_cnt);
1148 		if (IS_ERR(peer->mws)) {
1149 			dev_err(&ndev->ntb.pdev->dev,
1150 				"Failed to scan mws of port %hhu", peer->port);
1151 			return PTR_ERR(peer->mws);
1152 		}
1153 	}
1154 
1155 	/* Initialize spin locker of the LUT registers */
1156 	spin_lock_init(&ndev->lut_lock);
1157 
1158 	dev_dbg(&ndev->ntb.pdev->dev, "Outbound and inbound MWs initialized");
1159 
1160 	return 0;
1161 }
1162 
1163 /*
1164  * idt_ntb_mw_count() - number of inbound memory windows (NTB API callback)
1165  * @ntb:	NTB device context.
1166  * @pidx:	Port index of peer device.
1167  *
1168  * The value is returned for the specified peer, so generally speaking it can
1169  * be different for different port depending on the IDT PCIe-switch
1170  * initialization.
1171  *
1172  * Return: the number of memory windows.
1173  */
1174 static int idt_ntb_mw_count(struct ntb_dev *ntb, int pidx)
1175 {
1176 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1177 
1178 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1179 		return -EINVAL;
1180 
1181 	return ndev->peers[pidx].mw_cnt;
1182 }
1183 
1184 /*
1185  * idt_ntb_mw_get_align() - inbound memory window parameters (NTB API callback)
1186  * @ntb:	NTB device context.
1187  * @pidx:	Port index of peer device.
1188  * @widx:	Memory window index.
1189  * @addr_align:	OUT - the base alignment for translating the memory window
1190  * @size_align:	OUT - the size alignment for translating the memory window
1191  * @size_max:	OUT - the maximum size of the memory window
1192  *
1193  * The peer memory window parameters have already been determined, so just
1194  * return the corresponding values, which mustn't change within session.
1195  *
1196  * Return: Zero on success, otherwise a negative error number.
1197  */
1198 static int idt_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx,
1199 				resource_size_t *addr_align,
1200 				resource_size_t *size_align,
1201 				resource_size_t *size_max)
1202 {
1203 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1204 	struct idt_ntb_peer *peer;
1205 
1206 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1207 		return -EINVAL;
1208 
1209 	peer = &ndev->peers[pidx];
1210 
1211 	if (widx < 0 || peer->mw_cnt <= widx)
1212 		return -EINVAL;
1213 
1214 	if (addr_align != NULL)
1215 		*addr_align = peer->mws[widx].addr_align;
1216 
1217 	if (size_align != NULL)
1218 		*size_align = peer->mws[widx].size_align;
1219 
1220 	if (size_max != NULL)
1221 		*size_max = peer->mws[widx].size_max;
1222 
1223 	return 0;
1224 }
1225 
1226 /*
1227  * idt_ntb_peer_mw_count() - number of outbound memory windows
1228  *			     (NTB API callback)
1229  * @ntb:	NTB device context.
1230  *
1231  * Outbound memory windows parameters have been determined based on the
1232  * BAR setup registers value, which are mostly constants within one session.
1233  *
1234  * Return: the number of memory windows.
1235  */
1236 static int idt_ntb_peer_mw_count(struct ntb_dev *ntb)
1237 {
1238 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1239 
1240 	return ndev->mw_cnt;
1241 }
1242 
1243 /*
1244  * idt_ntb_peer_mw_get_addr() - get map address of an outbound memory window
1245  *				(NTB API callback)
1246  * @ntb:	NTB device context.
1247  * @widx:	Memory window index (within ntb_peer_mw_count() return value).
1248  * @base:	OUT - the base address of mapping region.
1249  * @size:	OUT - the size of mapping region.
1250  *
1251  * Return just parameters of BAR resources mapping. Size reflects just the size
1252  * of the resource
1253  *
1254  * Return: Zero on success, otherwise a negative error number.
1255  */
1256 static int idt_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int widx,
1257 				    phys_addr_t *base, resource_size_t *size)
1258 {
1259 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1260 
1261 	if (widx < 0 || ndev->mw_cnt <= widx)
1262 		return -EINVAL;
1263 
1264 	/* Mapping address is just properly shifted BAR resource start */
1265 	if (base != NULL)
1266 		*base = pci_resource_start(ntb->pdev, ndev->mws[widx].bar) +
1267 			ndev->mws[widx].idx * ndev->mws[widx].size_max;
1268 
1269 	/* Mapping size has already been calculated at MWs scanning */
1270 	if (size != NULL)
1271 		*size = ndev->mws[widx].size_max;
1272 
1273 	return 0;
1274 }
1275 
1276 /*
1277  * idt_ntb_peer_mw_set_trans() - set a translation address of a memory window
1278  *				 (NTB API callback)
1279  * @ntb:	NTB device context.
1280  * @pidx:	Port index of peer device the translation address received from.
1281  * @widx:	Memory window index.
1282  * @addr:	The dma address of the shared memory to access.
1283  * @size:	The size of the shared memory to access.
1284  *
1285  * The Direct address translation and LUT base translation is initialized a
1286  * bit differenet. Although the parameters restriction are now determined by
1287  * the same code.
1288  *
1289  * Return: Zero on success, otherwise an error number.
1290  */
1291 static int idt_ntb_peer_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
1292 				     u64 addr, resource_size_t size)
1293 {
1294 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1295 	struct idt_mw_cfg *mw_cfg;
1296 	u32 data = 0, lutoff = 0;
1297 
1298 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1299 		return -EINVAL;
1300 
1301 	if (widx < 0 || ndev->mw_cnt <= widx)
1302 		return -EINVAL;
1303 
1304 	/*
1305 	 * Retrieve the memory window config to make sure the passed arguments
1306 	 * fit it restrictions
1307 	 */
1308 	mw_cfg = &ndev->mws[widx];
1309 	if (!IS_ALIGNED(addr, mw_cfg->addr_align))
1310 		return -EINVAL;
1311 	if (!IS_ALIGNED(size, mw_cfg->size_align) || size > mw_cfg->size_max)
1312 		return -EINVAL;
1313 
1314 	/* DIR and LUT based translations are initialized differently */
1315 	if (mw_cfg->type == IDT_MW_DIR) {
1316 		const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
1317 		u64 limit;
1318 		/* Set destination partition of translation */
1319 		data = idt_nt_read(ndev, bar->setup);
1320 		data = SET_FIELD(BARSETUP_TPART, data, ndev->peers[pidx].part);
1321 		idt_nt_write(ndev, bar->setup, data);
1322 		/* Set translation base address */
1323 		idt_nt_write(ndev, bar->ltbase, (u32)addr);
1324 		idt_nt_write(ndev, bar->utbase, (u32)(addr >> 32));
1325 		/* Set the custom BAR aperture limit */
1326 		limit = pci_bus_address(ntb->pdev, mw_cfg->bar) + size;
1327 		idt_nt_write(ndev, bar->limit, (u32)limit);
1328 		if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
1329 			idt_nt_write(ndev, (bar + 1)->limit, (limit >> 32));
1330 	} else {
1331 		unsigned long irqflags;
1332 		/* Initialize corresponding LUT entry */
1333 		lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
1334 			 SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
1335 		data = SET_FIELD(LUTUDATA_PART, 0, ndev->peers[pidx].part) |
1336 			IDT_LUTUDATA_VALID;
1337 		spin_lock_irqsave(&ndev->lut_lock, irqflags);
1338 		idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
1339 		idt_nt_write(ndev, IDT_NT_LUTLDATA, (u32)addr);
1340 		idt_nt_write(ndev, IDT_NT_LUTMDATA, (u32)(addr >> 32));
1341 		idt_nt_write(ndev, IDT_NT_LUTUDATA, data);
1342 		mmiowb();
1343 		spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
1344 		/* Limit address isn't specified since size is fixed for LUT */
1345 	}
1346 
1347 	return 0;
1348 }
1349 
1350 /*
1351  * idt_ntb_peer_mw_clear_trans() - clear the outbound MW translation address
1352  *				   (NTB API callback)
1353  * @ntb:	NTB device context.
1354  * @pidx:	Port index of peer device.
1355  * @widx:	Memory window index.
1356  *
1357  * It effectively disables the translation over the specified outbound MW.
1358  *
1359  * Return: Zero on success, otherwise an error number.
1360  */
1361 static int idt_ntb_peer_mw_clear_trans(struct ntb_dev *ntb, int pidx,
1362 					int widx)
1363 {
1364 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1365 	struct idt_mw_cfg *mw_cfg;
1366 
1367 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1368 		return -EINVAL;
1369 
1370 	if (widx < 0 || ndev->mw_cnt <= widx)
1371 		return -EINVAL;
1372 
1373 	mw_cfg = &ndev->mws[widx];
1374 
1375 	/* DIR and LUT based translations are initialized differently */
1376 	if (mw_cfg->type == IDT_MW_DIR) {
1377 		const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
1378 		u32 data;
1379 		/* Read BARSETUP to check BAR type */
1380 		data = idt_nt_read(ndev, bar->setup);
1381 		/* Disable translation by specifying zero BAR limit */
1382 		idt_nt_write(ndev, bar->limit, 0);
1383 		if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
1384 			idt_nt_write(ndev, (bar + 1)->limit, 0);
1385 	} else {
1386 		unsigned long irqflags;
1387 		u32 lutoff;
1388 		/* Clear the corresponding LUT entry up */
1389 		lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
1390 			 SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
1391 		spin_lock_irqsave(&ndev->lut_lock, irqflags);
1392 		idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
1393 		idt_nt_write(ndev, IDT_NT_LUTLDATA, 0);
1394 		idt_nt_write(ndev, IDT_NT_LUTMDATA, 0);
1395 		idt_nt_write(ndev, IDT_NT_LUTUDATA, 0);
1396 		mmiowb();
1397 		spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
1398 	}
1399 
1400 	return 0;
1401 }
1402 
1403 /*=============================================================================
1404  *                          5. Doorbell operations
1405  *
1406  *    Doorbell functionality of IDT PCIe-switches is pretty unusual. First of
1407  * all there is global doorbell register which state can be changed by any
1408  * NT-function of the IDT device in accordance with global permissions. These
1409  * permissions configs are not supported by NTB API, so it must be done by
1410  * either BIOS or EEPROM settings. In the same way the state of the global
1411  * doorbell is reflected to the NT-functions local inbound doorbell registers.
1412  * It can lead to situations when client driver sets some peer doorbell bits
1413  * and get them bounced back to local inbound doorbell if permissions are
1414  * granted.
1415  *    Secondly there is just one IRQ vector for Doorbell, Message, Temperature
1416  * and Switch events, so if client driver left any of Doorbell bits set and
1417  * some other event occurred, the driver will be notified of Doorbell event
1418  * again.
1419  *=============================================================================
1420  */
1421 
1422 /*
1423  * idt_db_isr() - doorbell event ISR
1424  * @ndev:	IDT NTB hardware driver descriptor
1425  * @ntint_sts:	NT-function interrupt status
1426  *
1427  * Doorbell event happans when DBELL bit of NTINTSTS switches from 0 to 1.
1428  * It happens only when unmasked doorbell bits are set to ones on completely
1429  * zeroed doorbell register.
1430  * The method is called from PCIe ISR bottom-half routine.
1431  */
1432 static void idt_db_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
1433 {
1434 	/*
1435 	 * Doorbell IRQ status will be cleaned only when client
1436 	 * driver unsets all the doorbell bits.
1437 	 */
1438 	dev_dbg(&ndev->ntb.pdev->dev, "DB IRQ detected %#08x", ntint_sts);
1439 
1440 	/* Notify the client driver of possible doorbell state change */
1441 	ntb_db_event(&ndev->ntb, 0);
1442 }
1443 
1444 /*
1445  * idt_ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
1446  *			     (NTB API callback)
1447  * @ntb:	NTB device context.
1448  *
1449  * IDT PCIe-switches expose just one Doorbell register of DWORD size.
1450  *
1451  * Return: A mask of doorbell bits supported by the ntb.
1452  */
1453 static u64 idt_ntb_db_valid_mask(struct ntb_dev *ntb)
1454 {
1455 	return IDT_DBELL_MASK;
1456 }
1457 
1458 /*
1459  * idt_ntb_db_read() - read the local doorbell register (NTB API callback)
1460  * @ntb:	NTB device context.
1461  *
1462  * There is just on inbound doorbell register of each NT-function, so
1463  * this method return it value.
1464  *
1465  * Return: The bits currently set in the local doorbell register.
1466  */
1467 static u64 idt_ntb_db_read(struct ntb_dev *ntb)
1468 {
1469 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1470 
1471 	return idt_nt_read(ndev, IDT_NT_INDBELLSTS);
1472 }
1473 
1474 /*
1475  * idt_ntb_db_clear() - clear bits in the local doorbell register
1476  *			(NTB API callback)
1477  * @ntb:	NTB device context.
1478  * @db_bits:	Doorbell bits to clear.
1479  *
1480  * Clear bits of inbound doorbell register by writing ones to it.
1481  *
1482  * NOTE! Invalid bits are always considered cleared so it's not an error
1483  * to clear them over.
1484  *
1485  * Return: always zero as success.
1486  */
1487 static int idt_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
1488 {
1489 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1490 
1491 	idt_nt_write(ndev, IDT_NT_INDBELLSTS, (u32)db_bits);
1492 
1493 	return 0;
1494 }
1495 
1496 /*
1497  * idt_ntb_db_read_mask() - read the local doorbell mask (NTB API callback)
1498  * @ntb:	NTB device context.
1499  *
1500  * Each inbound doorbell bit can be masked from generating IRQ by setting
1501  * the corresponding bit in inbound doorbell mask. So this method returns
1502  * the value of the register.
1503  *
1504  * Return: The bits currently set in the local doorbell mask register.
1505  */
1506 static u64 idt_ntb_db_read_mask(struct ntb_dev *ntb)
1507 {
1508 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1509 
1510 	return idt_nt_read(ndev, IDT_NT_INDBELLMSK);
1511 }
1512 
1513 /*
1514  * idt_ntb_db_set_mask() - set bits in the local doorbell mask
1515  *			   (NTB API callback)
1516  * @ntb:	NTB device context.
1517  * @db_bits:	Doorbell mask bits to set.
1518  *
1519  * The inbound doorbell register mask value must be read, then OR'ed with
1520  * passed field and only then set back.
1521  *
1522  * Return: zero on success, negative error if invalid argument passed.
1523  */
1524 static int idt_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
1525 {
1526 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1527 
1528 	return idt_reg_set_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
1529 				IDT_DBELL_MASK, db_bits);
1530 }
1531 
1532 /*
1533  * idt_ntb_db_clear_mask() - clear bits in the local doorbell mask
1534  *			     (NTB API callback)
1535  * @ntb:	NTB device context.
1536  * @db_bits:	Doorbell bits to clear.
1537  *
1538  * The method just clears the set bits up in accordance with the passed
1539  * bitfield. IDT PCIe-switch shall generate an interrupt if there hasn't
1540  * been any unmasked bit set before current unmasking. Otherwise IRQ won't
1541  * be generated since there is only one IRQ vector for all doorbells.
1542  *
1543  * Return: always zero as success
1544  */
1545 static int idt_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
1546 {
1547 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1548 
1549 	idt_reg_clear_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
1550 			   db_bits);
1551 
1552 	return 0;
1553 }
1554 
1555 /*
1556  * idt_ntb_peer_db_set() - set bits in the peer doorbell register
1557  *			   (NTB API callback)
1558  * @ntb:	NTB device context.
1559  * @db_bits:	Doorbell bits to set.
1560  *
1561  * IDT PCIe-switches exposes local outbound doorbell register to change peer
1562  * inbound doorbell register state.
1563  *
1564  * Return: zero on success, negative error if invalid argument passed.
1565  */
1566 static int idt_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
1567 {
1568 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1569 
1570 	if (db_bits & ~(u64)IDT_DBELL_MASK)
1571 		return -EINVAL;
1572 
1573 	idt_nt_write(ndev, IDT_NT_OUTDBELLSET, (u32)db_bits);
1574 	return 0;
1575 }
1576 
1577 /*=============================================================================
1578  *                          6. Messaging operations
1579  *
1580  *    Each NT-function of IDT PCIe-switch has four inbound and four outbound
1581  * message registers. Each outbound message register can be connected to one or
1582  * even more than one peer inbound message registers by setting global
1583  * configurations. Since NTB API permits one-on-one message registers mapping
1584  * only, the driver acts in according with that restriction.
1585  *=============================================================================
1586  */
1587 
1588 /*
1589  * idt_init_msg() - initialize messaging interface
1590  * @ndev:	IDT NTB hardware driver descriptor
1591  *
1592  * Just initialize the message registers routing tables locker.
1593  */
1594 static void idt_init_msg(struct idt_ntb_dev *ndev)
1595 {
1596 	unsigned char midx;
1597 
1598 	/* Init the messages routing table lockers */
1599 	for (midx = 0; midx < IDT_MSG_CNT; midx++)
1600 		spin_lock_init(&ndev->msg_locks[midx]);
1601 
1602 	dev_dbg(&ndev->ntb.pdev->dev, "NTB Messaging initialized");
1603 }
1604 
1605 /*
1606  * idt_msg_isr() - message event ISR
1607  * @ndev:	IDT NTB hardware driver descriptor
1608  * @ntint_sts:	NT-function interrupt status
1609  *
1610  * Message event happens when MSG bit of NTINTSTS switches from 0 to 1.
1611  * It happens only when unmasked message status bits are set to ones on
1612  * completely zeroed message status register.
1613  * The method is called from PCIe ISR bottom-half routine.
1614  */
1615 static void idt_msg_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
1616 {
1617 	/*
1618 	 * Message IRQ status will be cleaned only when client
1619 	 * driver unsets all the message status bits.
1620 	 */
1621 	dev_dbg(&ndev->ntb.pdev->dev, "Message IRQ detected %#08x", ntint_sts);
1622 
1623 	/* Notify the client driver of possible message status change */
1624 	ntb_msg_event(&ndev->ntb);
1625 }
1626 
1627 /*
1628  * idt_ntb_msg_count() - get the number of message registers (NTB API callback)
1629  * @ntb:	NTB device context.
1630  *
1631  * IDT PCIe-switches support four message registers.
1632  *
1633  * Return: the number of message registers.
1634  */
1635 static int idt_ntb_msg_count(struct ntb_dev *ntb)
1636 {
1637 	return IDT_MSG_CNT;
1638 }
1639 
1640 /*
1641  * idt_ntb_msg_inbits() - get a bitfield of inbound message registers status
1642  *			  (NTB API callback)
1643  * @ntb:	NTB device context.
1644  *
1645  * NT message status register is shared between inbound and outbound message
1646  * registers status
1647  *
1648  * Return: bitfield of inbound message registers.
1649  */
1650 static u64 idt_ntb_msg_inbits(struct ntb_dev *ntb)
1651 {
1652 	return (u64)IDT_INMSG_MASK;
1653 }
1654 
1655 /*
1656  * idt_ntb_msg_outbits() - get a bitfield of outbound message registers status
1657  *			  (NTB API callback)
1658  * @ntb:	NTB device context.
1659  *
1660  * NT message status register is shared between inbound and outbound message
1661  * registers status
1662  *
1663  * Return: bitfield of outbound message registers.
1664  */
1665 static u64 idt_ntb_msg_outbits(struct ntb_dev *ntb)
1666 {
1667 	return (u64)IDT_OUTMSG_MASK;
1668 }
1669 
1670 /*
1671  * idt_ntb_msg_read_sts() - read the message registers status (NTB API callback)
1672  * @ntb:	NTB device context.
1673  *
1674  * IDT PCIe-switches expose message status registers to notify drivers of
1675  * incoming data and failures in case if peer message register isn't freed.
1676  *
1677  * Return: status bits of message registers
1678  */
1679 static u64 idt_ntb_msg_read_sts(struct ntb_dev *ntb)
1680 {
1681 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1682 
1683 	return idt_nt_read(ndev, IDT_NT_MSGSTS);
1684 }
1685 
1686 /*
1687  * idt_ntb_msg_clear_sts() - clear status bits of message registers
1688  *			     (NTB API callback)
1689  * @ntb:	NTB device context.
1690  * @sts_bits:	Status bits to clear.
1691  *
1692  * Clear bits in the status register by writing ones.
1693  *
1694  * NOTE! Invalid bits are always considered cleared so it's not an error
1695  * to clear them over.
1696  *
1697  * Return: always zero as success.
1698  */
1699 static int idt_ntb_msg_clear_sts(struct ntb_dev *ntb, u64 sts_bits)
1700 {
1701 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1702 
1703 	idt_nt_write(ndev, IDT_NT_MSGSTS, sts_bits);
1704 
1705 	return 0;
1706 }
1707 
1708 /*
1709  * idt_ntb_msg_set_mask() - set mask of message register status bits
1710  *			    (NTB API callback)
1711  * @ntb:	NTB device context.
1712  * @mask_bits:	Mask bits.
1713  *
1714  * Mask the message status bits from raising an IRQ.
1715  *
1716  * Return: zero on success, negative error if invalid argument passed.
1717  */
1718 static int idt_ntb_msg_set_mask(struct ntb_dev *ntb, u64 mask_bits)
1719 {
1720 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1721 
1722 	return idt_reg_set_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
1723 				IDT_MSG_MASK, mask_bits);
1724 }
1725 
1726 /*
1727  * idt_ntb_msg_clear_mask() - clear message registers mask
1728  *			      (NTB API callback)
1729  * @ntb:	NTB device context.
1730  * @mask_bits:	Mask bits.
1731  *
1732  * Clear mask of message status bits IRQs.
1733  *
1734  * Return: always zero as success.
1735  */
1736 static int idt_ntb_msg_clear_mask(struct ntb_dev *ntb, u64 mask_bits)
1737 {
1738 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1739 
1740 	idt_reg_clear_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
1741 			   mask_bits);
1742 
1743 	return 0;
1744 }
1745 
1746 /*
1747  * idt_ntb_msg_read() - read message register with specified index
1748  *			(NTB API callback)
1749  * @ntb:	NTB device context.
1750  * @pidx:	OUT - Port index of peer device a message retrieved from
1751  * @midx:	Message register index
1752  *
1753  * Read data from the specified message register and source register.
1754  *
1755  * Return: inbound message register value.
1756  */
1757 static u32 idt_ntb_msg_read(struct ntb_dev *ntb, int *pidx, int midx)
1758 {
1759 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1760 
1761 	if (midx < 0 || IDT_MSG_CNT <= midx)
1762 		return ~(u32)0;
1763 
1764 	/* Retrieve source port index of the message */
1765 	if (pidx != NULL) {
1766 		u32 srcpart;
1767 
1768 		srcpart = idt_nt_read(ndev, ntdata_tbl.msgs[midx].src);
1769 		*pidx = ndev->part_idx_map[srcpart];
1770 
1771 		/* Sanity check partition index (for initial case) */
1772 		if (*pidx == -EINVAL)
1773 			*pidx = 0;
1774 	}
1775 
1776 	/* Retrieve data of the corresponding message register */
1777 	return idt_nt_read(ndev, ntdata_tbl.msgs[midx].in);
1778 }
1779 
1780 /*
1781  * idt_ntb_peer_msg_write() - write data to the specified message register
1782  *			      (NTB API callback)
1783  * @ntb:	NTB device context.
1784  * @pidx:	Port index of peer device a message being sent to
1785  * @midx:	Message register index
1786  * @msg:	Data to send
1787  *
1788  * Just try to send data to a peer. Message status register should be
1789  * checked by client driver.
1790  *
1791  * Return: zero on success, negative error if invalid argument passed.
1792  */
1793 static int idt_ntb_peer_msg_write(struct ntb_dev *ntb, int pidx, int midx,
1794 				  u32 msg)
1795 {
1796 	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
1797 	unsigned long irqflags;
1798 	u32 swpmsgctl = 0;
1799 
1800 	if (midx < 0 || IDT_MSG_CNT <= midx)
1801 		return -EINVAL;
1802 
1803 	if (pidx < 0 || ndev->peer_cnt <= pidx)
1804 		return -EINVAL;
1805 
1806 	/* Collect the routing information */
1807 	swpmsgctl = SET_FIELD(SWPxMSGCTL_REG, 0, midx) |
1808 		    SET_FIELD(SWPxMSGCTL_PART, 0, ndev->peers[pidx].part);
1809 
1810 	/* Lock the messages routing table of the specified register */
1811 	spin_lock_irqsave(&ndev->msg_locks[midx], irqflags);
1812 	/* Set the route and send the data */
1813 	idt_sw_write(ndev, partdata_tbl[ndev->part].msgctl[midx], swpmsgctl);
1814 	idt_nt_write(ndev, ntdata_tbl.msgs[midx].out, msg);
1815 	mmiowb();
1816 	/* Unlock the messages routing table */
1817 	spin_unlock_irqrestore(&ndev->msg_locks[midx], irqflags);
1818 
1819 	/* Client driver shall check the status register */
1820 	return 0;
1821 }
1822 
1823 /*=============================================================================
1824  *                      7. Temperature sensor operations
1825  *
1826  *    IDT PCIe-switch has an embedded temperature sensor, which can be used to
1827  * check current chip core temperature. Since a workload environment can be
1828  * different on different platforms, an offset and ADC/filter settings can be
1829  * specified. Although the offset configuration is only exposed to the sysfs
1830  * hwmon interface at the moment. The rest of the settings can be adjusted
1831  * for instance by the BIOS/EEPROM firmware.
1832  *=============================================================================
1833  */
1834 
1835 /*
1836  * idt_get_deg() - convert millidegree Celsius value to just degree
1837  * @mdegC:	IN - millidegree Celsius value
1838  *
1839  * Return: Degree corresponding to the passed millidegree value
1840  */
1841 static inline s8 idt_get_deg(long mdegC)
1842 {
1843 	return mdegC / 1000;
1844 }
1845 
1846 /*
1847  * idt_get_frac() - retrieve 0/0.5 fraction of the millidegree Celsius value
1848  * @mdegC:	IN - millidegree Celsius value
1849  *
1850  * Return: 0/0.5 degree fraction of the passed millidegree value
1851  */
1852 static inline u8 idt_get_deg_frac(long mdegC)
1853 {
1854 	return (mdegC % 1000) >= 500 ? 5 : 0;
1855 }
1856 
1857 /*
1858  * idt_get_temp_fmt() - convert millidegree Celsius value to 0:7:1 format
1859  * @mdegC:	IN - millidegree Celsius value
1860  *
1861  * Return: 0:7:1 format acceptable by the IDT temperature sensor
1862  */
1863 static inline u8 idt_temp_get_fmt(long mdegC)
1864 {
1865 	return (idt_get_deg(mdegC) << 1) | (idt_get_deg_frac(mdegC) ? 1 : 0);
1866 }
1867 
1868 /*
1869  * idt_get_temp_sval() - convert temp sample to signed millidegree Celsius
1870  * @data:	IN - shifted to LSB 8-bits temperature sample
1871  *
1872  * Return: signed millidegree Celsius
1873  */
1874 static inline long idt_get_temp_sval(u32 data)
1875 {
1876 	return ((s8)data / 2) * 1000 + (data & 0x1 ? 500 : 0);
1877 }
1878 
1879 /*
1880  * idt_get_temp_sval() - convert temp sample to unsigned millidegree Celsius
1881  * @data:	IN - shifted to LSB 8-bits temperature sample
1882  *
1883  * Return: unsigned millidegree Celsius
1884  */
1885 static inline long idt_get_temp_uval(u32 data)
1886 {
1887 	return (data / 2) * 1000 + (data & 0x1 ? 500 : 0);
1888 }
1889 
1890 /*
1891  * idt_read_temp() - read temperature from chip sensor
1892  * @ntb:	NTB device context.
1893  * @type:	IN - type of the temperature value to read
1894  * @val:	OUT - integer value of temperature in millidegree Celsius
1895  */
1896 static void idt_read_temp(struct idt_ntb_dev *ndev,
1897 			  const enum idt_temp_val type, long *val)
1898 {
1899 	u32 data;
1900 
1901 	/* Alter the temperature field in accordance with the passed type */
1902 	switch (type) {
1903 	case IDT_TEMP_CUR:
1904 		data = GET_FIELD(TMPSTS_TEMP,
1905 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1906 		break;
1907 	case IDT_TEMP_LOW:
1908 		data = GET_FIELD(TMPSTS_LTEMP,
1909 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1910 		break;
1911 	case IDT_TEMP_HIGH:
1912 		data = GET_FIELD(TMPSTS_HTEMP,
1913 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1914 		break;
1915 	case IDT_TEMP_OFFSET:
1916 		/* This is the only field with signed 0:7:1 format */
1917 		data = GET_FIELD(TMPADJ_OFFSET,
1918 				 idt_sw_read(ndev, IDT_SW_TMPADJ));
1919 		*val = idt_get_temp_sval(data);
1920 		return;
1921 	default:
1922 		data = GET_FIELD(TMPSTS_TEMP,
1923 				 idt_sw_read(ndev, IDT_SW_TMPSTS));
1924 		break;
1925 	}
1926 
1927 	/* The rest of the fields accept unsigned 0:7:1 format */
1928 	*val = idt_get_temp_uval(data);
1929 }
1930 
1931 /*
1932  * idt_write_temp() - write temperature to the chip sensor register
1933  * @ntb:	NTB device context.
1934  * @type:	IN - type of the temperature value to change
1935  * @val:	IN - integer value of temperature in millidegree Celsius
1936  */
1937 static void idt_write_temp(struct idt_ntb_dev *ndev,
1938 			   const enum idt_temp_val type, const long val)
1939 {
1940 	unsigned int reg;
1941 	u32 data;
1942 	u8 fmt;
1943 
1944 	/* Retrieve the properly formatted temperature value */
1945 	fmt = idt_temp_get_fmt(val);
1946 
1947 	mutex_lock(&ndev->hwmon_mtx);
1948 	switch (type) {
1949 	case IDT_TEMP_LOW:
1950 		reg = IDT_SW_TMPALARM;
1951 		data = SET_FIELD(TMPALARM_LTEMP, idt_sw_read(ndev, reg), fmt) &
1952 			~IDT_TMPALARM_IRQ_MASK;
1953 		break;
1954 	case IDT_TEMP_HIGH:
1955 		reg = IDT_SW_TMPALARM;
1956 		data = SET_FIELD(TMPALARM_HTEMP, idt_sw_read(ndev, reg), fmt) &
1957 			~IDT_TMPALARM_IRQ_MASK;
1958 		break;
1959 	case IDT_TEMP_OFFSET:
1960 		reg = IDT_SW_TMPADJ;
1961 		data = SET_FIELD(TMPADJ_OFFSET, idt_sw_read(ndev, reg), fmt);
1962 		break;
1963 	default:
1964 		goto inval_spin_unlock;
1965 	}
1966 
1967 	idt_sw_write(ndev, reg, data);
1968 
1969 inval_spin_unlock:
1970 	mutex_unlock(&ndev->hwmon_mtx);
1971 }
1972 
1973 /*
1974  * idt_sysfs_show_temp() - printout corresponding temperature value
1975  * @dev:	Pointer to the NTB device structure
1976  * @da:		Sensor device attribute structure
1977  * @buf:	Buffer to print temperature out
1978  *
1979  * Return: Number of written symbols or negative error
1980  */
1981 static ssize_t idt_sysfs_show_temp(struct device *dev,
1982 				   struct device_attribute *da, char *buf)
1983 {
1984 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
1985 	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
1986 	enum idt_temp_val type = attr->index;
1987 	long mdeg;
1988 
1989 	idt_read_temp(ndev, type, &mdeg);
1990 	return sprintf(buf, "%ld\n", mdeg);
1991 }
1992 
1993 /*
1994  * idt_sysfs_set_temp() - set corresponding temperature value
1995  * @dev:	Pointer to the NTB device structure
1996  * @da:		Sensor device attribute structure
1997  * @buf:	Buffer to print temperature out
1998  * @count:	Size of the passed buffer
1999  *
2000  * Return: Number of written symbols or negative error
2001  */
2002 static ssize_t idt_sysfs_set_temp(struct device *dev,
2003 				  struct device_attribute *da, const char *buf,
2004 				  size_t count)
2005 {
2006 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
2007 	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
2008 	enum idt_temp_val type = attr->index;
2009 	long mdeg;
2010 	int ret;
2011 
2012 	ret = kstrtol(buf, 10, &mdeg);
2013 	if (ret)
2014 		return ret;
2015 
2016 	/* Clamp the passed value in accordance with the type */
2017 	if (type == IDT_TEMP_OFFSET)
2018 		mdeg = clamp_val(mdeg, IDT_TEMP_MIN_OFFSET,
2019 				 IDT_TEMP_MAX_OFFSET);
2020 	else
2021 		mdeg = clamp_val(mdeg, IDT_TEMP_MIN_MDEG, IDT_TEMP_MAX_MDEG);
2022 
2023 	idt_write_temp(ndev, type, mdeg);
2024 
2025 	return count;
2026 }
2027 
2028 /*
2029  * idt_sysfs_reset_hist() - reset temperature history
2030  * @dev:	Pointer to the NTB device structure
2031  * @da:		Sensor device attribute structure
2032  * @buf:	Buffer to print temperature out
2033  * @count:	Size of the passed buffer
2034  *
2035  * Return: Number of written symbols or negative error
2036  */
2037 static ssize_t idt_sysfs_reset_hist(struct device *dev,
2038 				    struct device_attribute *da,
2039 				    const char *buf, size_t count)
2040 {
2041 	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
2042 
2043 	/* Just set the maximal value to the lowest temperature field and
2044 	 * minimal value to the highest temperature field
2045 	 */
2046 	idt_write_temp(ndev, IDT_TEMP_LOW, IDT_TEMP_MAX_MDEG);
2047 	idt_write_temp(ndev, IDT_TEMP_HIGH, IDT_TEMP_MIN_MDEG);
2048 
2049 	return count;
2050 }
2051 
2052 /*
2053  * Hwmon IDT sysfs attributes
2054  */
2055 static SENSOR_DEVICE_ATTR(temp1_input, 0444, idt_sysfs_show_temp, NULL,
2056 			  IDT_TEMP_CUR);
2057 static SENSOR_DEVICE_ATTR(temp1_lowest, 0444, idt_sysfs_show_temp, NULL,
2058 			  IDT_TEMP_LOW);
2059 static SENSOR_DEVICE_ATTR(temp1_highest, 0444, idt_sysfs_show_temp, NULL,
2060 			  IDT_TEMP_HIGH);
2061 static SENSOR_DEVICE_ATTR(temp1_offset, 0644, idt_sysfs_show_temp,
2062 			  idt_sysfs_set_temp, IDT_TEMP_OFFSET);
2063 static DEVICE_ATTR(temp1_reset_history, 0200, NULL, idt_sysfs_reset_hist);
2064 
2065 /*
2066  * Hwmon IDT sysfs attributes group
2067  */
2068 static struct attribute *idt_temp_attrs[] = {
2069 	&sensor_dev_attr_temp1_input.dev_attr.attr,
2070 	&sensor_dev_attr_temp1_lowest.dev_attr.attr,
2071 	&sensor_dev_attr_temp1_highest.dev_attr.attr,
2072 	&sensor_dev_attr_temp1_offset.dev_attr.attr,
2073 	&dev_attr_temp1_reset_history.attr,
2074 	NULL
2075 };
2076 ATTRIBUTE_GROUPS(idt_temp);
2077 
2078 /*
2079  * idt_init_temp() - initialize temperature sensor interface
2080  * @ndev:	IDT NTB hardware driver descriptor
2081  *
2082  * Simple sensor initializarion method is responsible for device switching
2083  * on and resource management based hwmon interface registration. Note, that
2084  * since the device is shared we won't disable it on remove, but leave it
2085  * working until the system is powered off.
2086  */
2087 static void idt_init_temp(struct idt_ntb_dev *ndev)
2088 {
2089 	struct device *hwmon;
2090 
2091 	/* Enable sensor if it hasn't been already */
2092 	idt_sw_write(ndev, IDT_SW_TMPCTL, 0x0);
2093 
2094 	/* Initialize hwmon interface fields */
2095 	mutex_init(&ndev->hwmon_mtx);
2096 
2097 	hwmon = devm_hwmon_device_register_with_groups(&ndev->ntb.pdev->dev,
2098 		ndev->swcfg->name, ndev, idt_temp_groups);
2099 	if (IS_ERR(hwmon)) {
2100 		dev_err(&ndev->ntb.pdev->dev, "Couldn't create hwmon device");
2101 		return;
2102 	}
2103 
2104 	dev_dbg(&ndev->ntb.pdev->dev, "Temperature HWmon interface registered");
2105 }
2106 
2107 /*=============================================================================
2108  *                           8. ISRs related operations
2109  *
2110  *    IDT PCIe-switch has strangely developed IRQ system. There is just one
2111  * interrupt vector for doorbell and message registers. So the hardware driver
2112  * can't determine actual source of IRQ if, for example, message event happened
2113  * while any of unmasked doorbell is still set. The similar situation may be if
2114  * switch or temperature sensor events pop up. The difference is that SEVENT
2115  * and TMPSENSOR bits of NT interrupt status register can be cleaned by
2116  * IRQ handler so a next interrupt request won't have false handling of
2117  * corresponding events.
2118  *    The hardware driver has only bottom-half handler of the IRQ, since if any
2119  * of events happened the device won't raise it again before the last one is
2120  * handled by clearing of corresponding NTINTSTS bit.
2121  *=============================================================================
2122  */
2123 
2124 static irqreturn_t idt_thread_isr(int irq, void *devid);
2125 
2126 /*
2127  * idt_init_isr() - initialize PCIe interrupt handler
2128  * @ndev:	IDT NTB hardware driver descriptor
2129  *
2130  * Return: zero on success, otherwise a negative error number.
2131  */
2132 static int idt_init_isr(struct idt_ntb_dev *ndev)
2133 {
2134 	struct pci_dev *pdev = ndev->ntb.pdev;
2135 	u32 ntint_mask;
2136 	int ret;
2137 
2138 	/* Allocate just one interrupt vector for the ISR */
2139 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI | PCI_IRQ_LEGACY);
2140 	if (ret != 1) {
2141 		dev_err(&pdev->dev, "Failed to allocate IRQ vector");
2142 		return ret;
2143 	}
2144 
2145 	/* Retrieve the IRQ vector */
2146 	ret = pci_irq_vector(pdev, 0);
2147 	if (ret < 0) {
2148 		dev_err(&pdev->dev, "Failed to get IRQ vector");
2149 		goto err_free_vectors;
2150 	}
2151 
2152 	/* Set the IRQ handler */
2153 	ret = devm_request_threaded_irq(&pdev->dev, ret, NULL, idt_thread_isr,
2154 					IRQF_ONESHOT, NTB_IRQNAME, ndev);
2155 	if (ret != 0) {
2156 		dev_err(&pdev->dev, "Failed to set MSI IRQ handler, %d", ret);
2157 		goto err_free_vectors;
2158 	}
2159 
2160 	/* Unmask Message/Doorbell/SE interrupts */
2161 	ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) & ~IDT_NTINTMSK_ALL;
2162 	idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
2163 
2164 	/* From now on the interrupts are enabled */
2165 	dev_dbg(&pdev->dev, "NTB interrupts initialized");
2166 
2167 	return 0;
2168 
2169 err_free_vectors:
2170 	pci_free_irq_vectors(pdev);
2171 
2172 	return ret;
2173 }
2174 
2175 /*
2176  * idt_deinit_ist() - deinitialize PCIe interrupt handler
2177  * @ndev:	IDT NTB hardware driver descriptor
2178  *
2179  * Disable corresponding interrupts and free allocated IRQ vectors.
2180  */
2181 static void idt_deinit_isr(struct idt_ntb_dev *ndev)
2182 {
2183 	struct pci_dev *pdev = ndev->ntb.pdev;
2184 	u32 ntint_mask;
2185 
2186 	/* Mask interrupts back */
2187 	ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) | IDT_NTINTMSK_ALL;
2188 	idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
2189 
2190 	/* Manually free IRQ otherwise PCI free irq vectors will fail */
2191 	devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 0), ndev);
2192 
2193 	/* Free allocated IRQ vectors */
2194 	pci_free_irq_vectors(pdev);
2195 
2196 	dev_dbg(&pdev->dev, "NTB interrupts deinitialized");
2197 }
2198 
2199 /*
2200  * idt_thread_isr() - NT function interrupts handler
2201  * @irq:	IRQ number
2202  * @devid:	Custom buffer
2203  *
2204  * It reads current NT interrupts state register and handles all the event
2205  * it declares.
2206  * The method is bottom-half routine of actual default PCIe IRQ handler.
2207  */
2208 static irqreturn_t idt_thread_isr(int irq, void *devid)
2209 {
2210 	struct idt_ntb_dev *ndev = devid;
2211 	bool handled = false;
2212 	u32 ntint_sts;
2213 
2214 	/* Read the NT interrupts status register */
2215 	ntint_sts = idt_nt_read(ndev, IDT_NT_NTINTSTS);
2216 
2217 	/* Handle messaging interrupts */
2218 	if (ntint_sts & IDT_NTINTSTS_MSG) {
2219 		idt_msg_isr(ndev, ntint_sts);
2220 		handled = true;
2221 	}
2222 
2223 	/* Handle doorbell interrupts */
2224 	if (ntint_sts & IDT_NTINTSTS_DBELL) {
2225 		idt_db_isr(ndev, ntint_sts);
2226 		handled = true;
2227 	}
2228 
2229 	/* Handle switch event interrupts */
2230 	if (ntint_sts & IDT_NTINTSTS_SEVENT) {
2231 		idt_se_isr(ndev, ntint_sts);
2232 		handled = true;
2233 	}
2234 
2235 	dev_dbg(&ndev->ntb.pdev->dev, "IDT IRQs 0x%08x handled", ntint_sts);
2236 
2237 	return handled ? IRQ_HANDLED : IRQ_NONE;
2238 }
2239 
2240 /*===========================================================================
2241  *                     9. NTB hardware driver initialization
2242  *===========================================================================
2243  */
2244 
2245 /*
2246  * NTB API operations
2247  */
2248 static const struct ntb_dev_ops idt_ntb_ops = {
2249 	.port_number		= idt_ntb_port_number,
2250 	.peer_port_count	= idt_ntb_peer_port_count,
2251 	.peer_port_number	= idt_ntb_peer_port_number,
2252 	.peer_port_idx		= idt_ntb_peer_port_idx,
2253 	.link_is_up		= idt_ntb_link_is_up,
2254 	.link_enable		= idt_ntb_link_enable,
2255 	.link_disable		= idt_ntb_link_disable,
2256 	.mw_count		= idt_ntb_mw_count,
2257 	.mw_get_align		= idt_ntb_mw_get_align,
2258 	.peer_mw_count		= idt_ntb_peer_mw_count,
2259 	.peer_mw_get_addr	= idt_ntb_peer_mw_get_addr,
2260 	.peer_mw_set_trans	= idt_ntb_peer_mw_set_trans,
2261 	.peer_mw_clear_trans	= idt_ntb_peer_mw_clear_trans,
2262 	.db_valid_mask		= idt_ntb_db_valid_mask,
2263 	.db_read		= idt_ntb_db_read,
2264 	.db_clear		= idt_ntb_db_clear,
2265 	.db_read_mask		= idt_ntb_db_read_mask,
2266 	.db_set_mask		= idt_ntb_db_set_mask,
2267 	.db_clear_mask		= idt_ntb_db_clear_mask,
2268 	.peer_db_set		= idt_ntb_peer_db_set,
2269 	.msg_count		= idt_ntb_msg_count,
2270 	.msg_inbits		= idt_ntb_msg_inbits,
2271 	.msg_outbits		= idt_ntb_msg_outbits,
2272 	.msg_read_sts		= idt_ntb_msg_read_sts,
2273 	.msg_clear_sts		= idt_ntb_msg_clear_sts,
2274 	.msg_set_mask		= idt_ntb_msg_set_mask,
2275 	.msg_clear_mask		= idt_ntb_msg_clear_mask,
2276 	.msg_read		= idt_ntb_msg_read,
2277 	.peer_msg_write		= idt_ntb_peer_msg_write
2278 };
2279 
2280 /*
2281  * idt_register_device() - register IDT NTB device
2282  * @ndev:	IDT NTB hardware driver descriptor
2283  *
2284  * Return: zero on success, otherwise a negative error number.
2285  */
2286 static int idt_register_device(struct idt_ntb_dev *ndev)
2287 {
2288 	int ret;
2289 
2290 	/* Initialize the rest of NTB device structure and register it */
2291 	ndev->ntb.ops = &idt_ntb_ops;
2292 	ndev->ntb.topo = NTB_TOPO_SWITCH;
2293 
2294 	ret = ntb_register_device(&ndev->ntb);
2295 	if (ret != 0) {
2296 		dev_err(&ndev->ntb.pdev->dev, "Failed to register NTB device");
2297 		return ret;
2298 	}
2299 
2300 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device successfully registered");
2301 
2302 	return 0;
2303 }
2304 
2305 /*
2306  * idt_unregister_device() - unregister IDT NTB device
2307  * @ndev:	IDT NTB hardware driver descriptor
2308  */
2309 static void idt_unregister_device(struct idt_ntb_dev *ndev)
2310 {
2311 	/* Just unregister the NTB device */
2312 	ntb_unregister_device(&ndev->ntb);
2313 
2314 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device unregistered");
2315 }
2316 
2317 /*=============================================================================
2318  *                        10. DebugFS node initialization
2319  *=============================================================================
2320  */
2321 
2322 static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
2323 				   size_t count, loff_t *offp);
2324 
2325 /*
2326  * Driver DebugFS info file operations
2327  */
2328 static const struct file_operations idt_dbgfs_info_ops = {
2329 	.owner = THIS_MODULE,
2330 	.open = simple_open,
2331 	.read = idt_dbgfs_info_read
2332 };
2333 
2334 /*
2335  * idt_dbgfs_info_read() - DebugFS read info node callback
2336  * @file:	File node descriptor.
2337  * @ubuf:	User-space buffer to put data to
2338  * @count:	Size of the buffer
2339  * @offp:	Offset within the buffer
2340  */
2341 static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
2342 				   size_t count, loff_t *offp)
2343 {
2344 	struct idt_ntb_dev *ndev = filp->private_data;
2345 	unsigned char idx, pidx, cnt;
2346 	unsigned long irqflags, mdeg;
2347 	ssize_t ret = 0, off = 0;
2348 	enum ntb_speed speed;
2349 	enum ntb_width width;
2350 	char *strbuf;
2351 	size_t size;
2352 	u32 data;
2353 
2354 	/* Lets limit the buffer size the way the Intel/AMD drivers do */
2355 	size = min_t(size_t, count, 0x1000U);
2356 
2357 	/* Allocate the memory for the buffer */
2358 	strbuf = kmalloc(size, GFP_KERNEL);
2359 	if (strbuf == NULL)
2360 		return -ENOMEM;
2361 
2362 	/* Put the data into the string buffer */
2363 	off += scnprintf(strbuf + off, size - off,
2364 		"\n\t\tIDT NTB device Information:\n\n");
2365 
2366 	/* General local device configurations */
2367 	off += scnprintf(strbuf + off, size - off,
2368 		"Local Port %hhu, Partition %hhu\n", ndev->port, ndev->part);
2369 
2370 	/* Peer ports information */
2371 	off += scnprintf(strbuf + off, size - off, "Peers:\n");
2372 	for (idx = 0; idx < ndev->peer_cnt; idx++) {
2373 		off += scnprintf(strbuf + off, size - off,
2374 			"\t%hhu. Port %hhu, Partition %hhu\n",
2375 			idx, ndev->peers[idx].port, ndev->peers[idx].part);
2376 	}
2377 
2378 	/* Links status */
2379 	data = idt_ntb_link_is_up(&ndev->ntb, &speed, &width);
2380 	off += scnprintf(strbuf + off, size - off,
2381 		"NTB link status\t- 0x%08x, ", data);
2382 	off += scnprintf(strbuf + off, size - off, "PCIe Gen %d x%d lanes\n",
2383 		speed, width);
2384 
2385 	/* Mapping table entries */
2386 	off += scnprintf(strbuf + off, size - off, "NTB Mapping Table:\n");
2387 	for (idx = 0; idx < IDT_MTBL_ENTRY_CNT; idx++) {
2388 		spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
2389 		idt_nt_write(ndev, IDT_NT_NTMTBLADDR, idx);
2390 		data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
2391 		spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
2392 
2393 		/* Print valid entries only */
2394 		if (data & IDT_NTMTBLDATA_VALID) {
2395 			off += scnprintf(strbuf + off, size - off,
2396 				"\t%hhu. Partition %d, Requester ID 0x%04x\n",
2397 				idx, GET_FIELD(NTMTBLDATA_PART, data),
2398 				GET_FIELD(NTMTBLDATA_REQID, data));
2399 		}
2400 	}
2401 	off += scnprintf(strbuf + off, size - off, "\n");
2402 
2403 	/* Outbound memory windows information */
2404 	off += scnprintf(strbuf + off, size - off,
2405 		"Outbound Memory Windows:\n");
2406 	for (idx = 0; idx < ndev->mw_cnt; idx += cnt) {
2407 		data = ndev->mws[idx].type;
2408 		cnt = idt_get_mw_count(data);
2409 
2410 		/* Print Memory Window information */
2411 		if (data == IDT_MW_DIR)
2412 			off += scnprintf(strbuf + off, size - off,
2413 				"\t%hhu.\t", idx);
2414 		else
2415 			off += scnprintf(strbuf + off, size - off,
2416 				"\t%hhu-%hhu.\t", idx, idx + cnt - 1);
2417 
2418 		off += scnprintf(strbuf + off, size - off, "%s BAR%hhu, ",
2419 			idt_get_mw_name(data), ndev->mws[idx].bar);
2420 
2421 		off += scnprintf(strbuf + off, size - off,
2422 			"Address align 0x%08llx, ", ndev->mws[idx].addr_align);
2423 
2424 		off += scnprintf(strbuf + off, size - off,
2425 			"Size align 0x%08llx, Size max %llu\n",
2426 			ndev->mws[idx].size_align, ndev->mws[idx].size_max);
2427 	}
2428 
2429 	/* Inbound memory windows information */
2430 	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
2431 		off += scnprintf(strbuf + off, size - off,
2432 			"Inbound Memory Windows for peer %hhu (Port %hhu):\n",
2433 			pidx, ndev->peers[pidx].port);
2434 
2435 		/* Print Memory Windows information */
2436 		for (idx = 0; idx < ndev->peers[pidx].mw_cnt; idx += cnt) {
2437 			data = ndev->peers[pidx].mws[idx].type;
2438 			cnt = idt_get_mw_count(data);
2439 
2440 			if (data == IDT_MW_DIR)
2441 				off += scnprintf(strbuf + off, size - off,
2442 					"\t%hhu.\t", idx);
2443 			else
2444 				off += scnprintf(strbuf + off, size - off,
2445 					"\t%hhu-%hhu.\t", idx, idx + cnt - 1);
2446 
2447 			off += scnprintf(strbuf + off, size - off,
2448 				"%s BAR%hhu, ", idt_get_mw_name(data),
2449 				ndev->peers[pidx].mws[idx].bar);
2450 
2451 			off += scnprintf(strbuf + off, size - off,
2452 				"Address align 0x%08llx, ",
2453 				ndev->peers[pidx].mws[idx].addr_align);
2454 
2455 			off += scnprintf(strbuf + off, size - off,
2456 				"Size align 0x%08llx, Size max %llu\n",
2457 				ndev->peers[pidx].mws[idx].size_align,
2458 				ndev->peers[pidx].mws[idx].size_max);
2459 		}
2460 	}
2461 	off += scnprintf(strbuf + off, size - off, "\n");
2462 
2463 	/* Doorbell information */
2464 	data = idt_sw_read(ndev, IDT_SW_GDBELLSTS);
2465 	off += scnprintf(strbuf + off, size - off,
2466 		 "Global Doorbell state\t- 0x%08x\n", data);
2467 	data = idt_ntb_db_read(&ndev->ntb);
2468 	off += scnprintf(strbuf + off, size - off,
2469 		 "Local  Doorbell state\t- 0x%08x\n", data);
2470 	data = idt_nt_read(ndev, IDT_NT_INDBELLMSK);
2471 	off += scnprintf(strbuf + off, size - off,
2472 		 "Local  Doorbell mask\t- 0x%08x\n", data);
2473 	off += scnprintf(strbuf + off, size - off, "\n");
2474 
2475 	/* Messaging information */
2476 	off += scnprintf(strbuf + off, size - off,
2477 		 "Message event valid\t- 0x%08x\n", IDT_MSG_MASK);
2478 	data = idt_ntb_msg_read_sts(&ndev->ntb);
2479 	off += scnprintf(strbuf + off, size - off,
2480 		 "Message event status\t- 0x%08x\n", data);
2481 	data = idt_nt_read(ndev, IDT_NT_MSGSTSMSK);
2482 	off += scnprintf(strbuf + off, size - off,
2483 		 "Message event mask\t- 0x%08x\n", data);
2484 	off += scnprintf(strbuf + off, size - off,
2485 		 "Message data:\n");
2486 	for (idx = 0; idx < IDT_MSG_CNT; idx++) {
2487 		int src;
2488 		data = idt_ntb_msg_read(&ndev->ntb, &src, idx);
2489 		off += scnprintf(strbuf + off, size - off,
2490 			"\t%hhu. 0x%08x from peer %hhu (Port %hhu)\n",
2491 			idx, data, src, ndev->peers[src].port);
2492 	}
2493 	off += scnprintf(strbuf + off, size - off, "\n");
2494 
2495 	/* Current temperature */
2496 	idt_read_temp(ndev, IDT_TEMP_CUR, &mdeg);
2497 	off += scnprintf(strbuf + off, size - off,
2498 		"Switch temperature\t\t- %hhd.%hhuC\n",
2499 		idt_get_deg(mdeg), idt_get_deg_frac(mdeg));
2500 
2501 	/* Copy the buffer to the User Space */
2502 	ret = simple_read_from_buffer(ubuf, count, offp, strbuf, off);
2503 	kfree(strbuf);
2504 
2505 	return ret;
2506 }
2507 
2508 /*
2509  * idt_init_dbgfs() - initialize DebugFS node
2510  * @ndev:	IDT NTB hardware driver descriptor
2511  *
2512  * Return: zero on success, otherwise a negative error number.
2513  */
2514 static int idt_init_dbgfs(struct idt_ntb_dev *ndev)
2515 {
2516 	char devname[64];
2517 
2518 	/* If the top directory is not created then do nothing */
2519 	if (IS_ERR_OR_NULL(dbgfs_topdir)) {
2520 		dev_info(&ndev->ntb.pdev->dev, "Top DebugFS directory absent");
2521 		return PTR_ERR(dbgfs_topdir);
2522 	}
2523 
2524 	/* Create the info file node */
2525 	snprintf(devname, 64, "info:%s", pci_name(ndev->ntb.pdev));
2526 	ndev->dbgfs_info = debugfs_create_file(devname, 0400, dbgfs_topdir,
2527 		ndev, &idt_dbgfs_info_ops);
2528 	if (IS_ERR(ndev->dbgfs_info)) {
2529 		dev_dbg(&ndev->ntb.pdev->dev, "Failed to create DebugFS node");
2530 		return PTR_ERR(ndev->dbgfs_info);
2531 	}
2532 
2533 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node created");
2534 
2535 	return 0;
2536 }
2537 
2538 /*
2539  * idt_deinit_dbgfs() - deinitialize DebugFS node
2540  * @ndev:	IDT NTB hardware driver descriptor
2541  *
2542  * Just discard the info node from DebugFS
2543  */
2544 static void idt_deinit_dbgfs(struct idt_ntb_dev *ndev)
2545 {
2546 	debugfs_remove(ndev->dbgfs_info);
2547 
2548 	dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node discarded");
2549 }
2550 
2551 /*=============================================================================
2552  *                     11. Basic PCIe device initialization
2553  *=============================================================================
2554  */
2555 
2556 /*
2557  * idt_check_setup() - Check whether the IDT PCIe-swtich is properly
2558  *		       pre-initialized
2559  * @pdev:	Pointer to the PCI device descriptor
2560  *
2561  * Return: zero on success, otherwise a negative error number.
2562  */
2563 static int idt_check_setup(struct pci_dev *pdev)
2564 {
2565 	u32 data;
2566 	int ret;
2567 
2568 	/* Read the BARSETUP0 */
2569 	ret = pci_read_config_dword(pdev, IDT_NT_BARSETUP0, &data);
2570 	if (ret != 0) {
2571 		dev_err(&pdev->dev,
2572 			"Failed to read BARSETUP0 config register");
2573 		return ret;
2574 	}
2575 
2576 	/* Check whether the BAR0 register is enabled to be of config space */
2577 	if (!(data & IDT_BARSETUP_EN) || !(data & IDT_BARSETUP_MODE_CFG)) {
2578 		dev_err(&pdev->dev, "BAR0 doesn't map config space");
2579 		return -EINVAL;
2580 	}
2581 
2582 	/* Configuration space BAR0 must have certain size */
2583 	if ((data & IDT_BARSETUP_SIZE_MASK) != IDT_BARSETUP_SIZE_CFG) {
2584 		dev_err(&pdev->dev, "Invalid size of config space");
2585 		return -EINVAL;
2586 	}
2587 
2588 	dev_dbg(&pdev->dev, "NTB device pre-initialized correctly");
2589 
2590 	return 0;
2591 }
2592 
2593 /*
2594  * Create the IDT PCIe-switch driver descriptor
2595  * @pdev:	Pointer to the PCI device descriptor
2596  * @id:		IDT PCIe-device configuration
2597  *
2598  * It just allocates a memory for IDT PCIe-switch device structure and
2599  * initializes some commonly used fields.
2600  *
2601  * No need of release method, since managed device resource is used for
2602  * memory allocation.
2603  *
2604  * Return: pointer to the descriptor, otherwise a negative error number.
2605  */
2606 static struct idt_ntb_dev *idt_create_dev(struct pci_dev *pdev,
2607 					  const struct pci_device_id *id)
2608 {
2609 	struct idt_ntb_dev *ndev;
2610 
2611 	/* Allocate memory for the IDT PCIe-device descriptor */
2612 	ndev = devm_kzalloc(&pdev->dev, sizeof(*ndev), GFP_KERNEL);
2613 	if (!ndev) {
2614 		dev_err(&pdev->dev, "Memory allocation failed for descriptor");
2615 		return ERR_PTR(-ENOMEM);
2616 	}
2617 
2618 	/* Save the IDT PCIe-switch ports configuration */
2619 	ndev->swcfg = (struct idt_89hpes_cfg *)id->driver_data;
2620 	/* Save the PCI-device pointer inside the NTB device structure */
2621 	ndev->ntb.pdev = pdev;
2622 
2623 	/* Initialize spin locker of Doorbell, Message and GASA registers */
2624 	spin_lock_init(&ndev->db_mask_lock);
2625 	spin_lock_init(&ndev->msg_mask_lock);
2626 	spin_lock_init(&ndev->gasa_lock);
2627 
2628 	dev_info(&pdev->dev, "IDT %s discovered", ndev->swcfg->name);
2629 
2630 	dev_dbg(&pdev->dev, "NTB device descriptor created");
2631 
2632 	return ndev;
2633 }
2634 
2635 /*
2636  * idt_init_pci() - initialize the basic PCI-related subsystem
2637  * @ndev:	Pointer to the IDT PCIe-switch driver descriptor
2638  *
2639  * Managed device resources will be freed automatically in case of failure or
2640  * driver detachment.
2641  *
2642  * Return: zero on success, otherwise negative error number.
2643  */
2644 static int idt_init_pci(struct idt_ntb_dev *ndev)
2645 {
2646 	struct pci_dev *pdev = ndev->ntb.pdev;
2647 	int ret;
2648 
2649 	/* Initialize the bit mask of PCI/NTB DMA */
2650 	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
2651 	if (ret != 0) {
2652 		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
2653 		if (ret != 0) {
2654 			dev_err(&pdev->dev, "Failed to set DMA bit mask\n");
2655 			return ret;
2656 		}
2657 		dev_warn(&pdev->dev, "Cannot set DMA highmem bit mask\n");
2658 	}
2659 	ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
2660 	if (ret != 0) {
2661 		ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
2662 		if (ret != 0) {
2663 			dev_err(&pdev->dev,
2664 				"Failed to set consistent DMA bit mask\n");
2665 			return ret;
2666 		}
2667 		dev_warn(&pdev->dev,
2668 			"Cannot set consistent DMA highmem bit mask\n");
2669 	}
2670 	ret = dma_coerce_mask_and_coherent(&ndev->ntb.dev,
2671 					   dma_get_mask(&pdev->dev));
2672 	if (ret != 0) {
2673 		dev_err(&pdev->dev, "Failed to set NTB device DMA bit mask\n");
2674 		return ret;
2675 	}
2676 
2677 	/*
2678 	 * Enable the device advanced error reporting. It's not critical to
2679 	 * have AER disabled in the kernel.
2680 	 */
2681 	ret = pci_enable_pcie_error_reporting(pdev);
2682 	if (ret != 0)
2683 		dev_warn(&pdev->dev, "PCIe AER capability disabled\n");
2684 	else /* Cleanup uncorrectable error status before getting to init */
2685 		pci_cleanup_aer_uncorrect_error_status(pdev);
2686 
2687 	/* First enable the PCI device */
2688 	ret = pcim_enable_device(pdev);
2689 	if (ret != 0) {
2690 		dev_err(&pdev->dev, "Failed to enable PCIe device\n");
2691 		goto err_disable_aer;
2692 	}
2693 
2694 	/*
2695 	 * Enable the bus mastering, which effectively enables MSI IRQs and
2696 	 * Request TLPs translation
2697 	 */
2698 	pci_set_master(pdev);
2699 
2700 	/* Request all BARs resources and map BAR0 only */
2701 	ret = pcim_iomap_regions_request_all(pdev, 1, NTB_NAME);
2702 	if (ret != 0) {
2703 		dev_err(&pdev->dev, "Failed to request resources\n");
2704 		goto err_clear_master;
2705 	}
2706 
2707 	/* Retrieve virtual address of BAR0 - PCI configuration space */
2708 	ndev->cfgspc = pcim_iomap_table(pdev)[0];
2709 
2710 	/* Put the IDT driver data pointer to the PCI-device private pointer */
2711 	pci_set_drvdata(pdev, ndev);
2712 
2713 	dev_dbg(&pdev->dev, "NT-function PCIe interface initialized");
2714 
2715 	return 0;
2716 
2717 err_clear_master:
2718 	pci_clear_master(pdev);
2719 err_disable_aer:
2720 	(void)pci_disable_pcie_error_reporting(pdev);
2721 
2722 	return ret;
2723 }
2724 
2725 /*
2726  * idt_deinit_pci() - deinitialize the basic PCI-related subsystem
2727  * @ndev:	Pointer to the IDT PCIe-switch driver descriptor
2728  *
2729  * Managed resources will be freed on the driver detachment
2730  */
2731 static void idt_deinit_pci(struct idt_ntb_dev *ndev)
2732 {
2733 	struct pci_dev *pdev = ndev->ntb.pdev;
2734 
2735 	/* Clean up the PCI-device private data pointer */
2736 	pci_set_drvdata(pdev, NULL);
2737 
2738 	/* Clear the bus master disabling the Request TLPs translation */
2739 	pci_clear_master(pdev);
2740 
2741 	/* Disable the AER capability */
2742 	(void)pci_disable_pcie_error_reporting(pdev);
2743 
2744 	dev_dbg(&pdev->dev, "NT-function PCIe interface cleared");
2745 }
2746 
2747 /*===========================================================================
2748  *                       12. PCI bus callback functions
2749  *===========================================================================
2750  */
2751 
2752 /*
2753  * idt_pci_probe() - PCI device probe callback
2754  * @pdev:	Pointer to PCI device structure
2755  * @id:		PCIe device custom descriptor
2756  *
2757  * Return: zero on success, otherwise negative error number
2758  */
2759 static int idt_pci_probe(struct pci_dev *pdev,
2760 			 const struct pci_device_id *id)
2761 {
2762 	struct idt_ntb_dev *ndev;
2763 	int ret;
2764 
2765 	/* Check whether IDT PCIe-switch is properly pre-initialized */
2766 	ret = idt_check_setup(pdev);
2767 	if (ret != 0)
2768 		return ret;
2769 
2770 	/* Allocate the memory for IDT NTB device data */
2771 	ndev = idt_create_dev(pdev, id);
2772 	if (IS_ERR_OR_NULL(ndev))
2773 		return PTR_ERR(ndev);
2774 
2775 	/* Initialize the basic PCI subsystem of the device */
2776 	ret = idt_init_pci(ndev);
2777 	if (ret != 0)
2778 		return ret;
2779 
2780 	/* Scan ports of the IDT PCIe-switch */
2781 	(void)idt_scan_ports(ndev);
2782 
2783 	/* Initialize NTB link events subsystem */
2784 	idt_init_link(ndev);
2785 
2786 	/* Initialize MWs subsystem */
2787 	ret = idt_init_mws(ndev);
2788 	if (ret != 0)
2789 		goto err_deinit_link;
2790 
2791 	/* Initialize Messaging subsystem */
2792 	idt_init_msg(ndev);
2793 
2794 	/* Initialize hwmon interface */
2795 	idt_init_temp(ndev);
2796 
2797 	/* Initialize IDT interrupts handler */
2798 	ret = idt_init_isr(ndev);
2799 	if (ret != 0)
2800 		goto err_deinit_link;
2801 
2802 	/* Register IDT NTB devices on the NTB bus */
2803 	ret = idt_register_device(ndev);
2804 	if (ret != 0)
2805 		goto err_deinit_isr;
2806 
2807 	/* Initialize DebugFS info node */
2808 	(void)idt_init_dbgfs(ndev);
2809 
2810 	/* IDT PCIe-switch NTB driver is finally initialized */
2811 	dev_info(&pdev->dev, "IDT NTB device is ready");
2812 
2813 	/* May the force be with us... */
2814 	return 0;
2815 
2816 err_deinit_isr:
2817 	idt_deinit_isr(ndev);
2818 err_deinit_link:
2819 	idt_deinit_link(ndev);
2820 	idt_deinit_pci(ndev);
2821 
2822 	return ret;
2823 }
2824 
2825 /*
2826  * idt_pci_probe() - PCI device remove callback
2827  * @pdev:	Pointer to PCI device structure
2828  */
2829 static void idt_pci_remove(struct pci_dev *pdev)
2830 {
2831 	struct idt_ntb_dev *ndev = pci_get_drvdata(pdev);
2832 
2833 	/* Deinit the DebugFS node */
2834 	idt_deinit_dbgfs(ndev);
2835 
2836 	/* Unregister NTB device */
2837 	idt_unregister_device(ndev);
2838 
2839 	/* Stop the interrupts handling */
2840 	idt_deinit_isr(ndev);
2841 
2842 	/* Deinitialize link event subsystem */
2843 	idt_deinit_link(ndev);
2844 
2845 	/* Deinit basic PCI subsystem */
2846 	idt_deinit_pci(ndev);
2847 
2848 	/* IDT PCIe-switch NTB driver is finally initialized */
2849 	dev_info(&pdev->dev, "IDT NTB device is removed");
2850 
2851 	/* Sayonara... */
2852 }
2853 
2854 /*
2855  * IDT PCIe-switch models ports configuration structures
2856  */
2857 static const struct idt_89hpes_cfg idt_89hpes24nt6ag2_config = {
2858 	.name = "89HPES24NT6AG2",
2859 	.port_cnt = 6, .ports = {0, 2, 4, 6, 8, 12}
2860 };
2861 static const struct idt_89hpes_cfg idt_89hpes32nt8ag2_config = {
2862 	.name = "89HPES32NT8AG2",
2863 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2864 };
2865 static const struct idt_89hpes_cfg idt_89hpes32nt8bg2_config = {
2866 	.name = "89HPES32NT8BG2",
2867 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2868 };
2869 static const struct idt_89hpes_cfg idt_89hpes12nt12g2_config = {
2870 	.name = "89HPES12NT12G2",
2871 	.port_cnt = 3, .ports = {0, 8, 16}
2872 };
2873 static const struct idt_89hpes_cfg idt_89hpes16nt16g2_config = {
2874 	.name = "89HPES16NT16G2",
2875 	.port_cnt = 4, .ports = {0, 8, 12, 16}
2876 };
2877 static const struct idt_89hpes_cfg idt_89hpes24nt24g2_config = {
2878 	.name = "89HPES24NT24G2",
2879 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2880 };
2881 static const struct idt_89hpes_cfg idt_89hpes32nt24ag2_config = {
2882 	.name = "89HPES32NT24AG2",
2883 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2884 };
2885 static const struct idt_89hpes_cfg idt_89hpes32nt24bg2_config = {
2886 	.name = "89HPES32NT24BG2",
2887 	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
2888 };
2889 
2890 /*
2891  * PCI-ids table of the supported IDT PCIe-switch devices
2892  */
2893 static const struct pci_device_id idt_pci_tbl[] = {
2894 	{IDT_PCI_DEVICE_IDS(89HPES24NT6AG2,  idt_89hpes24nt6ag2_config)},
2895 	{IDT_PCI_DEVICE_IDS(89HPES32NT8AG2,  idt_89hpes32nt8ag2_config)},
2896 	{IDT_PCI_DEVICE_IDS(89HPES32NT8BG2,  idt_89hpes32nt8bg2_config)},
2897 	{IDT_PCI_DEVICE_IDS(89HPES12NT12G2,  idt_89hpes12nt12g2_config)},
2898 	{IDT_PCI_DEVICE_IDS(89HPES16NT16G2,  idt_89hpes16nt16g2_config)},
2899 	{IDT_PCI_DEVICE_IDS(89HPES24NT24G2,  idt_89hpes24nt24g2_config)},
2900 	{IDT_PCI_DEVICE_IDS(89HPES32NT24AG2, idt_89hpes32nt24ag2_config)},
2901 	{IDT_PCI_DEVICE_IDS(89HPES32NT24BG2, idt_89hpes32nt24bg2_config)},
2902 	{0}
2903 };
2904 MODULE_DEVICE_TABLE(pci, idt_pci_tbl);
2905 
2906 /*
2907  * IDT PCIe-switch NT-function device driver structure definition
2908  */
2909 static struct pci_driver idt_pci_driver = {
2910 	.name		= KBUILD_MODNAME,
2911 	.probe		= idt_pci_probe,
2912 	.remove		= idt_pci_remove,
2913 	.id_table	= idt_pci_tbl,
2914 };
2915 
2916 static int __init idt_pci_driver_init(void)
2917 {
2918 	pr_info("%s %s\n", NTB_DESC, NTB_VER);
2919 
2920 	/* Create the top DebugFS directory if the FS is initialized */
2921 	if (debugfs_initialized())
2922 		dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
2923 
2924 	/* Register the NTB hardware driver to handle the PCI device */
2925 	return pci_register_driver(&idt_pci_driver);
2926 }
2927 module_init(idt_pci_driver_init);
2928 
2929 static void __exit idt_pci_driver_exit(void)
2930 {
2931 	/* Unregister the NTB hardware driver */
2932 	pci_unregister_driver(&idt_pci_driver);
2933 
2934 	/* Discard the top DebugFS directory */
2935 	debugfs_remove_recursive(dbgfs_topdir);
2936 }
2937 module_exit(idt_pci_driver_exit);
2938 
2939