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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2015 - 2016 Cavium, Inc.
4 */
5
6#include <linux/bitfield.h>
7#include <linux/kernel.h>
8#include <linux/init.h>
9#include <linux/pci.h>
10#include <linux/of_address.h>
11#include <linux/of_pci.h>
12#include <linux/pci-acpi.h>
13#include <linux/pci-ecam.h>
14#include <linux/platform_device.h>
15#include "../pci.h"
16
17#if defined(CONFIG_PCI_HOST_THUNDER_PEM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
18
19#define PEM_CFG_WR 0x28
20#define PEM_CFG_RD 0x30
21
22struct thunder_pem_pci {
23 u32 ea_entry[3];
24 void __iomem *pem_reg_base;
25};
26
27static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
28 int where, int size, u32 *val)
29{
30 u64 read_val, tmp_val;
31 struct pci_config_window *cfg = bus->sysdata;
32 struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
33
34 if (devfn != 0 || where >= 2048) {
35 *val = ~0;
36 return PCIBIOS_DEVICE_NOT_FOUND;
37 }
38
39 /*
40 * 32-bit accesses only. Write the address to the low order
41 * bits of PEM_CFG_RD, then trigger the read by reading back.
42 * The config data lands in the upper 32-bits of PEM_CFG_RD.
43 */
44 read_val = where & ~3ull;
45 writeq(read_val, pem_pci->pem_reg_base + PEM_CFG_RD);
46 read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
47 read_val >>= 32;
48
49 /*
50 * The config space contains some garbage, fix it up. Also
51 * synthesize an EA capability for the BAR used by MSI-X.
52 */
53 switch (where & ~3) {
54 case 0x40:
55 read_val &= 0xffff00ff;
56 read_val |= 0x00007000; /* Skip MSI CAP */
57 break;
58 case 0x70: /* Express Cap */
59 /*
60 * Change PME interrupt to vector 2 on T88 where it
61 * reads as 0, else leave it alone.
62 */
63 if (!(read_val & (0x1f << 25)))
64 read_val |= (2u << 25);
65 break;
66 case 0xb0: /* MSI-X Cap */
67 /* TableSize=2 or 4, Next Cap is EA */
68 read_val &= 0xc00000ff;
69 /*
70 * If Express Cap(0x70) raw PME vector reads as 0 we are on
71 * T88 and TableSize is reported as 4, else TableSize
72 * is 2.
73 */
74 writeq(0x70, pem_pci->pem_reg_base + PEM_CFG_RD);
75 tmp_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
76 tmp_val >>= 32;
77 if (!(tmp_val & (0x1f << 25)))
78 read_val |= 0x0003bc00;
79 else
80 read_val |= 0x0001bc00;
81 break;
82 case 0xb4:
83 /* Table offset=0, BIR=0 */
84 read_val = 0x00000000;
85 break;
86 case 0xb8:
87 /* BPA offset=0xf0000, BIR=0 */
88 read_val = 0x000f0000;
89 break;
90 case 0xbc:
91 /* EA, 1 entry, no next Cap */
92 read_val = 0x00010014;
93 break;
94 case 0xc0:
95 /* DW2 for type-1 */
96 read_val = 0x00000000;
97 break;
98 case 0xc4:
99 /* Entry BEI=0, PP=0x00, SP=0xff, ES=3 */
100 read_val = 0x80ff0003;
101 break;
102 case 0xc8:
103 read_val = pem_pci->ea_entry[0];
104 break;
105 case 0xcc:
106 read_val = pem_pci->ea_entry[1];
107 break;
108 case 0xd0:
109 read_val = pem_pci->ea_entry[2];
110 break;
111 default:
112 break;
113 }
114 read_val >>= (8 * (where & 3));
115 switch (size) {
116 case 1:
117 read_val &= 0xff;
118 break;
119 case 2:
120 read_val &= 0xffff;
121 break;
122 default:
123 break;
124 }
125 *val = read_val;
126 return PCIBIOS_SUCCESSFUL;
127}
128
129static int thunder_pem_config_read(struct pci_bus *bus, unsigned int devfn,
130 int where, int size, u32 *val)
131{
132 struct pci_config_window *cfg = bus->sysdata;
133
134 if (bus->number < cfg->busr.start ||
135 bus->number > cfg->busr.end)
136 return PCIBIOS_DEVICE_NOT_FOUND;
137
138 /*
139 * The first device on the bus is the PEM PCIe bridge.
140 * Special case its config access.
141 */
142 if (bus->number == cfg->busr.start)
143 return thunder_pem_bridge_read(bus, devfn, where, size, val);
144
145 return pci_generic_config_read(bus, devfn, where, size, val);
146}
147
148/*
149 * Some of the w1c_bits below also include read-only or non-writable
150 * reserved bits, this makes the code simpler and is OK as the bits
151 * are not affected by writing zeros to them.
152 */
153static u32 thunder_pem_bridge_w1c_bits(u64 where_aligned)
154{
155 u32 w1c_bits = 0;
156
157 switch (where_aligned) {
158 case 0x04: /* Command/Status */
159 case 0x1c: /* Base and I/O Limit/Secondary Status */
160 w1c_bits = 0xff000000;
161 break;
162 case 0x44: /* Power Management Control and Status */
163 w1c_bits = 0xfffffe00;
164 break;
165 case 0x78: /* Device Control/Device Status */
166 case 0x80: /* Link Control/Link Status */
167 case 0x88: /* Slot Control/Slot Status */
168 case 0x90: /* Root Status */
169 case 0xa0: /* Link Control 2 Registers/Link Status 2 */
170 w1c_bits = 0xffff0000;
171 break;
172 case 0x104: /* Uncorrectable Error Status */
173 case 0x110: /* Correctable Error Status */
174 case 0x130: /* Error Status */
175 case 0x160: /* Link Control 4 */
176 w1c_bits = 0xffffffff;
177 break;
178 default:
179 break;
180 }
181 return w1c_bits;
182}
183
184/* Some bits must be written to one so they appear to be read-only. */
185static u32 thunder_pem_bridge_w1_bits(u64 where_aligned)
186{
187 u32 w1_bits;
188
189 switch (where_aligned) {
190 case 0x1c: /* I/O Base / I/O Limit, Secondary Status */
191 /* Force 32-bit I/O addressing. */
192 w1_bits = 0x0101;
193 break;
194 case 0x24: /* Prefetchable Memory Base / Prefetchable Memory Limit */
195 /* Force 64-bit addressing */
196 w1_bits = 0x00010001;
197 break;
198 default:
199 w1_bits = 0;
200 break;
201 }
202 return w1_bits;
203}
204
205static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
206 int where, int size, u32 val)
207{
208 struct pci_config_window *cfg = bus->sysdata;
209 struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
210 u64 write_val, read_val;
211 u64 where_aligned = where & ~3ull;
212 u32 mask = 0;
213
214
215 if (devfn != 0 || where >= 2048)
216 return PCIBIOS_DEVICE_NOT_FOUND;
217
218 /*
219 * 32-bit accesses only. If the write is for a size smaller
220 * than 32-bits, we must first read the 32-bit value and merge
221 * in the desired bits and then write the whole 32-bits back
222 * out.
223 */
224 switch (size) {
225 case 1:
226 writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
227 read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
228 read_val >>= 32;
229 mask = ~(0xff << (8 * (where & 3)));
230 read_val &= mask;
231 val = (val & 0xff) << (8 * (where & 3));
232 val |= (u32)read_val;
233 break;
234 case 2:
235 writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
236 read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
237 read_val >>= 32;
238 mask = ~(0xffff << (8 * (where & 3)));
239 read_val &= mask;
240 val = (val & 0xffff) << (8 * (where & 3));
241 val |= (u32)read_val;
242 break;
243 default:
244 break;
245 }
246
247 /*
248 * By expanding the write width to 32 bits, we may
249 * inadvertently hit some W1C bits that were not intended to
250 * be written. Calculate the mask that must be applied to the
251 * data to be written to avoid these cases.
252 */
253 if (mask) {
254 u32 w1c_bits = thunder_pem_bridge_w1c_bits(where);
255
256 if (w1c_bits) {
257 mask &= w1c_bits;
258 val &= ~mask;
259 }
260 }
261
262 /*
263 * Some bits must be read-only with value of one. Since the
264 * access method allows these to be cleared if a zero is
265 * written, force them to one before writing.
266 */
267 val |= thunder_pem_bridge_w1_bits(where_aligned);
268
269 /*
270 * Low order bits are the config address, the high order 32
271 * bits are the data to be written.
272 */
273 write_val = (((u64)val) << 32) | where_aligned;
274 writeq(write_val, pem_pci->pem_reg_base + PEM_CFG_WR);
275 return PCIBIOS_SUCCESSFUL;
276}
277
278static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
279 int where, int size, u32 val)
280{
281 struct pci_config_window *cfg = bus->sysdata;
282
283 if (bus->number < cfg->busr.start ||
284 bus->number > cfg->busr.end)
285 return PCIBIOS_DEVICE_NOT_FOUND;
286 /*
287 * The first device on the bus is the PEM PCIe bridge.
288 * Special case its config access.
289 */
290 if (bus->number == cfg->busr.start)
291 return thunder_pem_bridge_write(bus, devfn, where, size, val);
292
293
294 return pci_generic_config_write(bus, devfn, where, size, val);
295}
296
297static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg,
298 struct resource *res_pem)
299{
300 struct thunder_pem_pci *pem_pci;
301 resource_size_t bar4_start;
302
303 pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
304 if (!pem_pci)
305 return -ENOMEM;
306
307 pem_pci->pem_reg_base = devm_ioremap(dev, res_pem->start, 0x10000);
308 if (!pem_pci->pem_reg_base)
309 return -ENOMEM;
310
311 /*
312 * The MSI-X BAR for the PEM and AER interrupts is located at
313 * a fixed offset from the PEM register base. Generate a
314 * fragment of the synthesized Enhanced Allocation capability
315 * structure here for the BAR.
316 */
317 bar4_start = res_pem->start + 0xf00000;
318 pem_pci->ea_entry[0] = (u32)bar4_start | 2;
319 pem_pci->ea_entry[1] = (u32)(res_pem->end - bar4_start) & ~3u;
320 pem_pci->ea_entry[2] = (u32)(bar4_start >> 32);
321
322 cfg->priv = pem_pci;
323 return 0;
324}
325
326#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
327
328#define PEM_RES_BASE 0x87e0c0000000UL
329#define PEM_NODE_MASK GENMASK(45, 44)
330#define PEM_INDX_MASK GENMASK(26, 24)
331#define PEM_MIN_DOM_IN_NODE 4
332#define PEM_MAX_DOM_IN_NODE 10
333
334static void thunder_pem_reserve_range(struct device *dev, int seg,
335 struct resource *r)
336{
337 resource_size_t start = r->start, end = r->end;
338 struct resource *res;
339 const char *regionid;
340
341 regionid = kasprintf(GFP_KERNEL, "PEM RC:%d", seg);
342 if (!regionid)
343 return;
344
345 res = request_mem_region(start, end - start + 1, regionid);
346 if (res)
347 res->flags &= ~IORESOURCE_BUSY;
348 else
349 kfree(regionid);
350
351 dev_info(dev, "%pR %s reserved\n", r,
352 res ? "has been" : "could not be");
353}
354
355static void thunder_pem_legacy_fw(struct acpi_pci_root *root,
356 struct resource *res_pem)
357{
358 int node = acpi_get_node(root->device->handle);
359 int index;
360
361 if (node == NUMA_NO_NODE)
362 node = 0;
363
364 index = root->segment - PEM_MIN_DOM_IN_NODE;
365 index -= node * PEM_MAX_DOM_IN_NODE;
366 res_pem->start = PEM_RES_BASE | FIELD_PREP(PEM_NODE_MASK, node) |
367 FIELD_PREP(PEM_INDX_MASK, index);
368 res_pem->flags = IORESOURCE_MEM;
369}
370
371static int thunder_pem_acpi_init(struct pci_config_window *cfg)
372{
373 struct device *dev = cfg->parent;
374 struct acpi_device *adev = to_acpi_device(dev);
375 struct acpi_pci_root *root = acpi_driver_data(adev);
376 struct resource *res_pem;
377 int ret;
378
379 res_pem = devm_kzalloc(&adev->dev, sizeof(*res_pem), GFP_KERNEL);
380 if (!res_pem)
381 return -ENOMEM;
382
383 ret = acpi_get_rc_resources(dev, "CAVA02B", root->segment, res_pem);
384
385 /*
386 * If we fail to gather resources it means that we run with old
387 * FW where we need to calculate PEM-specific resources manually.
388 */
389 if (ret) {
390 thunder_pem_legacy_fw(root, res_pem);
391 /*
392 * Reserve 64K size PEM specific resources. The full 16M range
393 * size is required for thunder_pem_init() call.
394 */
395 res_pem->end = res_pem->start + SZ_64K - 1;
396 thunder_pem_reserve_range(dev, root->segment, res_pem);
397 res_pem->end = res_pem->start + SZ_16M - 1;
398
399 /* Reserve PCI configuration space as well. */
400 thunder_pem_reserve_range(dev, root->segment, &cfg->res);
401 }
402
403 return thunder_pem_init(dev, cfg, res_pem);
404}
405
406const struct pci_ecam_ops thunder_pem_ecam_ops = {
407 .bus_shift = 24,
408 .init = thunder_pem_acpi_init,
409 .pci_ops = {
410 .map_bus = pci_ecam_map_bus,
411 .read = thunder_pem_config_read,
412 .write = thunder_pem_config_write,
413 }
414};
415
416#endif
417
418#ifdef CONFIG_PCI_HOST_THUNDER_PEM
419
420static int thunder_pem_platform_init(struct pci_config_window *cfg)
421{
422 struct device *dev = cfg->parent;
423 struct platform_device *pdev = to_platform_device(dev);
424 struct resource *res_pem;
425
426 if (!dev->of_node)
427 return -EINVAL;
428
429 /*
430 * The second register range is the PEM bridge to the PCIe
431 * bus. It has a different config access method than those
432 * devices behind the bridge.
433 */
434 res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
435 if (!res_pem) {
436 dev_err(dev, "missing \"reg[1]\"property\n");
437 return -EINVAL;
438 }
439
440 return thunder_pem_init(dev, cfg, res_pem);
441}
442
443static const struct pci_ecam_ops pci_thunder_pem_ops = {
444 .bus_shift = 24,
445 .init = thunder_pem_platform_init,
446 .pci_ops = {
447 .map_bus = pci_ecam_map_bus,
448 .read = thunder_pem_config_read,
449 .write = thunder_pem_config_write,
450 }
451};
452
453static const struct of_device_id thunder_pem_of_match[] = {
454 {
455 .compatible = "cavium,pci-host-thunder-pem",
456 .data = &pci_thunder_pem_ops,
457 },
458 { },
459};
460
461static struct platform_driver thunder_pem_driver = {
462 .driver = {
463 .name = KBUILD_MODNAME,
464 .of_match_table = thunder_pem_of_match,
465 .suppress_bind_attrs = true,
466 },
467 .probe = pci_host_common_probe,
468};
469builtin_platform_driver(thunder_pem_driver);
470
471#endif
472#endif