1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2015, 2016 Cavium, Inc.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/init.h>
8 #include <linux/ioport.h>
9 #include <linux/of_pci.h>
10 #include <linux/of.h>
11 #include <linux/pci-ecam.h>
12 #include <linux/platform_device.h>
13 
14 #include "pci-host-common.h"
15 
16 #if defined(CONFIG_PCI_HOST_THUNDER_ECAM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
17 
18 static void set_val(u32 v, int where, int size, u32 *val)
19 {
20 	int shift = (where & 3) * 8;
21 
22 	pr_debug("set_val %04x: %08x\n", (unsigned int)(where & ~3), v);
23 	v >>= shift;
24 	if (size == 1)
25 		v &= 0xff;
26 	else if (size == 2)
27 		v &= 0xffff;
28 	*val = v;
29 }
30 
31 static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
32 			 unsigned int devfn, int where, int size, u32 *val)
33 {
34 	void __iomem *addr;
35 	u32 v;
36 
37 	/* Entries are 16-byte aligned; bits[2,3] select word in entry */
38 	int where_a = where & 0xc;
39 
40 	if (where_a == 0) {
41 		set_val(e0, where, size, val);
42 		return PCIBIOS_SUCCESSFUL;
43 	}
44 	if (where_a == 0x4) {
45 		addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
46 		if (!addr)
47 			return PCIBIOS_DEVICE_NOT_FOUND;
48 
49 		v = readl(addr);
50 		v &= ~0xf;
51 		v |= 2; /* EA entry-1. Base-L */
52 		set_val(v, where, size, val);
53 		return PCIBIOS_SUCCESSFUL;
54 	}
55 	if (where_a == 0x8) {
56 		u32 barl_orig;
57 		u32 barl_rb;
58 
59 		addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
60 		if (!addr)
61 			return PCIBIOS_DEVICE_NOT_FOUND;
62 
63 		barl_orig = readl(addr + 0);
64 		writel(0xffffffff, addr + 0);
65 		barl_rb = readl(addr + 0);
66 		writel(barl_orig, addr + 0);
67 		/* zeros in unsettable bits */
68 		v = ~barl_rb & ~3;
69 		v |= 0xc; /* EA entry-2. Offset-L */
70 		set_val(v, where, size, val);
71 		return PCIBIOS_SUCCESSFUL;
72 	}
73 	if (where_a == 0xc) {
74 		addr = bus->ops->map_bus(bus, devfn, bar + 4); /* BAR 1 */
75 		if (!addr)
76 			return PCIBIOS_DEVICE_NOT_FOUND;
77 
78 		v = readl(addr); /* EA entry-3. Base-H */
79 		set_val(v, where, size, val);
80 		return PCIBIOS_SUCCESSFUL;
81 	}
82 	return PCIBIOS_DEVICE_NOT_FOUND;
83 }
84 
85 static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
86 				       int where, int size, u32 *val)
87 {
88 	struct pci_config_window *cfg = bus->sysdata;
89 	int where_a = where & ~3;
90 	void __iomem *addr;
91 	u32 node_bits;
92 	u32 v;
93 
94 	/* EA Base[63:32] may be missing some bits ... */
95 	switch (where_a) {
96 	case 0xa8:
97 	case 0xbc:
98 	case 0xd0:
99 	case 0xe4:
100 		break;
101 	default:
102 		return pci_generic_config_read(bus, devfn, where, size, val);
103 	}
104 
105 	addr = bus->ops->map_bus(bus, devfn, where_a);
106 	if (!addr)
107 		return PCIBIOS_DEVICE_NOT_FOUND;
108 
109 	v = readl(addr);
110 
111 	/*
112 	 * Bit 44 of the 64-bit Base must match the same bit in
113 	 * the config space access window.  Since we are working with
114 	 * the high-order 32 bits, shift everything down by 32 bits.
115 	 */
116 	node_bits = upper_32_bits(cfg->res.start) & (1 << 12);
117 
118 	v |= node_bits;
119 	set_val(v, where, size, val);
120 
121 	return PCIBIOS_SUCCESSFUL;
122 }
123 
124 static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
125 				    int where, int size, u32 *val)
126 {
127 	u32 v;
128 	u32 vendor_device;
129 	u32 class_rev;
130 	void __iomem *addr;
131 	int cfg_type;
132 	int where_a = where & ~3;
133 
134 	addr = bus->ops->map_bus(bus, devfn, 0xc);
135 	if (!addr)
136 		return PCIBIOS_DEVICE_NOT_FOUND;
137 
138 	v = readl(addr);
139 
140 	/* Check for non type-00 header */
141 	cfg_type = (v >> 16) & 0x7f;
142 
143 	addr = bus->ops->map_bus(bus, devfn, 8);
144 	if (!addr)
145 		return PCIBIOS_DEVICE_NOT_FOUND;
146 
147 	class_rev = readl(addr);
148 	if (class_rev == 0xffffffff)
149 		goto no_emulation;
150 
151 	if ((class_rev & 0xff) >= 8) {
152 		/* Pass-2 handling */
153 		if (cfg_type)
154 			goto no_emulation;
155 		return thunder_ecam_p2_config_read(bus, devfn, where,
156 						   size, val);
157 	}
158 
159 	/*
160 	 * All BARs have fixed addresses specified by the EA
161 	 * capability; they must return zero on read.
162 	 */
163 	if (cfg_type == 0 &&
164 	    ((where >= 0x10 && where < 0x2c) ||
165 	     (where >= 0x1a4 && where < 0x1bc))) {
166 		/* BAR or SR-IOV BAR */
167 		*val = 0;
168 		return PCIBIOS_SUCCESSFUL;
169 	}
170 
171 	addr = bus->ops->map_bus(bus, devfn, 0);
172 	if (!addr)
173 		return PCIBIOS_DEVICE_NOT_FOUND;
174 
175 	vendor_device = readl(addr);
176 	if (vendor_device == 0xffffffff)
177 		goto no_emulation;
178 
179 	pr_debug("%04x:%04x - Fix pass#: %08x, where: %03x, devfn: %03x\n",
180 		 vendor_device & 0xffff, vendor_device >> 16, class_rev,
181 		 (unsigned int)where, devfn);
182 
183 	/* Check for non type-00 header */
184 	if (cfg_type == 0) {
185 		bool has_msix;
186 		bool is_nic = (vendor_device == 0xa01e177d);
187 		bool is_tns = (vendor_device == 0xa01f177d);
188 
189 		addr = bus->ops->map_bus(bus, devfn, 0x70);
190 		if (!addr)
191 			return PCIBIOS_DEVICE_NOT_FOUND;
192 
193 		/* E_CAP */
194 		v = readl(addr);
195 		has_msix = (v & 0xff00) != 0;
196 
197 		if (!has_msix && where_a == 0x70) {
198 			v |= 0xbc00; /* next capability is EA at 0xbc */
199 			set_val(v, where, size, val);
200 			return PCIBIOS_SUCCESSFUL;
201 		}
202 		if (where_a == 0xb0) {
203 			addr = bus->ops->map_bus(bus, devfn, where_a);
204 			if (!addr)
205 				return PCIBIOS_DEVICE_NOT_FOUND;
206 
207 			v = readl(addr);
208 			if (v & 0xff00)
209 				pr_err("Bad MSI-X cap header: %08x\n", v);
210 			v |= 0xbc00; /* next capability is EA at 0xbc */
211 			set_val(v, where, size, val);
212 			return PCIBIOS_SUCCESSFUL;
213 		}
214 		if (where_a == 0xbc) {
215 			if (is_nic)
216 				v = 0x40014; /* EA last in chain, 4 entries */
217 			else if (is_tns)
218 				v = 0x30014; /* EA last in chain, 3 entries */
219 			else if (has_msix)
220 				v = 0x20014; /* EA last in chain, 2 entries */
221 			else
222 				v = 0x10014; /* EA last in chain, 1 entry */
223 			set_val(v, where, size, val);
224 			return PCIBIOS_SUCCESSFUL;
225 		}
226 		if (where_a >= 0xc0 && where_a < 0xd0)
227 			/* EA entry-0. PP=0, BAR0 Size:3 */
228 			return handle_ea_bar(0x80ff0003,
229 					     0x10, bus, devfn, where,
230 					     size, val);
231 		if (where_a >= 0xd0 && where_a < 0xe0 && has_msix)
232 			 /* EA entry-1. PP=0, BAR4 Size:3 */
233 			return handle_ea_bar(0x80ff0043,
234 					     0x20, bus, devfn, where,
235 					     size, val);
236 		if (where_a >= 0xe0 && where_a < 0xf0 && is_tns)
237 			/* EA entry-2. PP=0, BAR2, Size:3 */
238 			return handle_ea_bar(0x80ff0023,
239 					     0x18, bus, devfn, where,
240 					     size, val);
241 		if (where_a >= 0xe0 && where_a < 0xf0 && is_nic)
242 			/* EA entry-2. PP=4, VF_BAR0 (9), Size:3 */
243 			return handle_ea_bar(0x80ff0493,
244 					     0x1a4, bus, devfn, where,
245 					     size, val);
246 		if (where_a >= 0xf0 && where_a < 0x100 && is_nic)
247 			/* EA entry-3. PP=4, VF_BAR4 (d), Size:3 */
248 			return handle_ea_bar(0x80ff04d3,
249 					     0x1b4, bus, devfn, where,
250 					     size, val);
251 	} else if (cfg_type == 1) {
252 		bool is_rsl_bridge = devfn == 0x08;
253 		bool is_rad_bridge = devfn == 0xa0;
254 		bool is_zip_bridge = devfn == 0xa8;
255 		bool is_dfa_bridge = devfn == 0xb0;
256 		bool is_nic_bridge = devfn == 0x10;
257 
258 		if (where_a == 0x70) {
259 			addr = bus->ops->map_bus(bus, devfn, where_a);
260 			if (!addr)
261 				return PCIBIOS_DEVICE_NOT_FOUND;
262 
263 			v = readl(addr);
264 			if (v & 0xff00)
265 				pr_err("Bad PCIe cap header: %08x\n", v);
266 			v |= 0xbc00; /* next capability is EA at 0xbc */
267 			set_val(v, where, size, val);
268 			return PCIBIOS_SUCCESSFUL;
269 		}
270 		if (where_a == 0xbc) {
271 			if (is_nic_bridge)
272 				v = 0x10014; /* EA last in chain, 1 entry */
273 			else
274 				v = 0x00014; /* EA last in chain, no entries */
275 			set_val(v, where, size, val);
276 			return PCIBIOS_SUCCESSFUL;
277 		}
278 		if (where_a == 0xc0) {
279 			if (is_rsl_bridge || is_nic_bridge)
280 				v = 0x0101; /* subordinate:secondary = 1:1 */
281 			else if (is_rad_bridge)
282 				v = 0x0202; /* subordinate:secondary = 2:2 */
283 			else if (is_zip_bridge)
284 				v = 0x0303; /* subordinate:secondary = 3:3 */
285 			else if (is_dfa_bridge)
286 				v = 0x0404; /* subordinate:secondary = 4:4 */
287 			set_val(v, where, size, val);
288 			return PCIBIOS_SUCCESSFUL;
289 		}
290 		if (where_a == 0xc4 && is_nic_bridge) {
291 			/* Enabled, not-Write, SP=ff, PP=05, BEI=6, ES=4 */
292 			v = 0x80ff0564;
293 			set_val(v, where, size, val);
294 			return PCIBIOS_SUCCESSFUL;
295 		}
296 		if (where_a == 0xc8 && is_nic_bridge) {
297 			v = 0x00000002; /* Base-L 64-bit */
298 			set_val(v, where, size, val);
299 			return PCIBIOS_SUCCESSFUL;
300 		}
301 		if (where_a == 0xcc && is_nic_bridge) {
302 			v = 0xfffffffe; /* MaxOffset-L 64-bit */
303 			set_val(v, where, size, val);
304 			return PCIBIOS_SUCCESSFUL;
305 		}
306 		if (where_a == 0xd0 && is_nic_bridge) {
307 			v = 0x00008430; /* NIC Base-H */
308 			set_val(v, where, size, val);
309 			return PCIBIOS_SUCCESSFUL;
310 		}
311 		if (where_a == 0xd4 && is_nic_bridge) {
312 			v = 0x0000000f; /* MaxOffset-H */
313 			set_val(v, where, size, val);
314 			return PCIBIOS_SUCCESSFUL;
315 		}
316 	}
317 no_emulation:
318 	return pci_generic_config_read(bus, devfn, where, size, val);
319 }
320 
321 static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,
322 				     int where, int size, u32 val)
323 {
324 	/*
325 	 * All BARs have fixed addresses; ignore BAR writes so they
326 	 * don't get corrupted.
327 	 */
328 	if ((where >= 0x10 && where < 0x2c) ||
329 	    (where >= 0x1a4 && where < 0x1bc))
330 		/* BAR or SR-IOV BAR */
331 		return PCIBIOS_SUCCESSFUL;
332 
333 	return pci_generic_config_write(bus, devfn, where, size, val);
334 }
335 
336 const struct pci_ecam_ops pci_thunder_ecam_ops = {
337 	.pci_ops	= {
338 		.map_bus        = pci_ecam_map_bus,
339 		.read           = thunder_ecam_config_read,
340 		.write          = thunder_ecam_config_write,
341 	}
342 };
343 
344 #ifdef CONFIG_PCI_HOST_THUNDER_ECAM
345 
346 static const struct of_device_id thunder_ecam_of_match[] = {
347 	{
348 		.compatible = "cavium,pci-host-thunder-ecam",
349 		.data = &pci_thunder_ecam_ops,
350 	},
351 	{ },
352 };
353 
354 static struct platform_driver thunder_ecam_driver = {
355 	.driver = {
356 		.name = KBUILD_MODNAME,
357 		.of_match_table = thunder_ecam_of_match,
358 		.suppress_bind_attrs = true,
359 	},
360 	.probe = pci_host_common_probe,
361 };
362 builtin_platform_driver(thunder_ecam_driver);
363 
364 #endif
365 #endif
366