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 <linux/io-64-nonatomic-lo-hi.h>
16 #include "../pci.h"
17
18 #if defined(CONFIG_PCI_HOST_THUNDER_PEM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
19
20 #define PEM_CFG_WR 0x28
21 #define PEM_CFG_RD 0x30
22
23 /*
24 * Enhanced Configuration Access Mechanism (ECAM)
25 *
26 * N.B. This is a non-standard platform-specific ECAM bus shift value. For
27 * standard values defined in the PCI Express Base Specification see
28 * include/linux/pci-ecam.h.
29 */
30 #define THUNDER_PCIE_ECAM_BUS_SHIFT 24
31
32 struct thunder_pem_pci {
33 u32 ea_entry[3];
34 void __iomem *pem_reg_base;
35 };
36
thunder_pem_bridge_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)37 static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
38 int where, int size, u32 *val)
39 {
40 u64 read_val, tmp_val;
41 struct pci_config_window *cfg = bus->sysdata;
42 struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
43
44 if (devfn != 0 || where >= 2048) {
45 *val = ~0;
46 return PCIBIOS_DEVICE_NOT_FOUND;
47 }
48
49 /*
50 * 32-bit accesses only. Write the address to the low order
51 * bits of PEM_CFG_RD, then trigger the read by reading back.
52 * The config data lands in the upper 32-bits of PEM_CFG_RD.
53 */
54 read_val = where & ~3ull;
55 writeq(read_val, pem_pci->pem_reg_base + PEM_CFG_RD);
56 read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
57 read_val >>= 32;
58
59 /*
60 * The config space contains some garbage, fix it up. Also
61 * synthesize an EA capability for the BAR used by MSI-X.
62 */
63 switch (where & ~3) {
64 case 0x40:
65 read_val &= 0xffff00ff;
66 read_val |= 0x00007000; /* Skip MSI CAP */
67 break;
68 case 0x70: /* Express Cap */
69 /*
70 * Change PME interrupt to vector 2 on T88 where it
71 * reads as 0, else leave it alone.
72 */
73 if (!(read_val & (0x1f << 25)))
74 read_val |= (2u << 25);
75 break;
76 case 0xb0: /* MSI-X Cap */
77 /* TableSize=2 or 4, Next Cap is EA */
78 read_val &= 0xc00000ff;
79 /*
80 * If Express Cap(0x70) raw PME vector reads as 0 we are on
81 * T88 and TableSize is reported as 4, else TableSize
82 * is 2.
83 */
84 writeq(0x70, pem_pci->pem_reg_base + PEM_CFG_RD);
85 tmp_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
86 tmp_val >>= 32;
87 if (!(tmp_val & (0x1f << 25)))
88 read_val |= 0x0003bc00;
89 else
90 read_val |= 0x0001bc00;
91 break;
92 case 0xb4:
93 /* Table offset=0, BIR=0 */
94 read_val = 0x00000000;
95 break;
96 case 0xb8:
97 /* BPA offset=0xf0000, BIR=0 */
98 read_val = 0x000f0000;
99 break;
100 case 0xbc:
101 /* EA, 1 entry, no next Cap */
102 read_val = 0x00010014;
103 break;
104 case 0xc0:
105 /* DW2 for type-1 */
106 read_val = 0x00000000;
107 break;
108 case 0xc4:
109 /* Entry BEI=0, PP=0x00, SP=0xff, ES=3 */
110 read_val = 0x80ff0003;
111 break;
112 case 0xc8:
113 read_val = pem_pci->ea_entry[0];
114 break;
115 case 0xcc:
116 read_val = pem_pci->ea_entry[1];
117 break;
118 case 0xd0:
119 read_val = pem_pci->ea_entry[2];
120 break;
121 default:
122 break;
123 }
124 read_val >>= (8 * (where & 3));
125 switch (size) {
126 case 1:
127 read_val &= 0xff;
128 break;
129 case 2:
130 read_val &= 0xffff;
131 break;
132 default:
133 break;
134 }
135 *val = read_val;
136 return PCIBIOS_SUCCESSFUL;
137 }
138
thunder_pem_config_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)139 static int thunder_pem_config_read(struct pci_bus *bus, unsigned int devfn,
140 int where, int size, u32 *val)
141 {
142 struct pci_config_window *cfg = bus->sysdata;
143
144 if (bus->number < cfg->busr.start ||
145 bus->number > cfg->busr.end)
146 return PCIBIOS_DEVICE_NOT_FOUND;
147
148 /*
149 * The first device on the bus is the PEM PCIe bridge.
150 * Special case its config access.
151 */
152 if (bus->number == cfg->busr.start)
153 return thunder_pem_bridge_read(bus, devfn, where, size, val);
154
155 return pci_generic_config_read(bus, devfn, where, size, val);
156 }
157
158 /*
159 * Some of the w1c_bits below also include read-only or non-writable
160 * reserved bits, this makes the code simpler and is OK as the bits
161 * are not affected by writing zeros to them.
162 */
thunder_pem_bridge_w1c_bits(u64 where_aligned)163 static u32 thunder_pem_bridge_w1c_bits(u64 where_aligned)
164 {
165 u32 w1c_bits = 0;
166
167 switch (where_aligned) {
168 case 0x04: /* Command/Status */
169 case 0x1c: /* Base and I/O Limit/Secondary Status */
170 w1c_bits = 0xff000000;
171 break;
172 case 0x44: /* Power Management Control and Status */
173 w1c_bits = 0xfffffe00;
174 break;
175 case 0x78: /* Device Control/Device Status */
176 case 0x80: /* Link Control/Link Status */
177 case 0x88: /* Slot Control/Slot Status */
178 case 0x90: /* Root Status */
179 case 0xa0: /* Link Control 2 Registers/Link Status 2 */
180 w1c_bits = 0xffff0000;
181 break;
182 case 0x104: /* Uncorrectable Error Status */
183 case 0x110: /* Correctable Error Status */
184 case 0x130: /* Error Status */
185 case 0x160: /* Link Control 4 */
186 w1c_bits = 0xffffffff;
187 break;
188 default:
189 break;
190 }
191 return w1c_bits;
192 }
193
194 /* Some bits must be written to one so they appear to be read-only. */
thunder_pem_bridge_w1_bits(u64 where_aligned)195 static u32 thunder_pem_bridge_w1_bits(u64 where_aligned)
196 {
197 u32 w1_bits;
198
199 switch (where_aligned) {
200 case 0x1c: /* I/O Base / I/O Limit, Secondary Status */
201 /* Force 32-bit I/O addressing. */
202 w1_bits = 0x0101;
203 break;
204 case 0x24: /* Prefetchable Memory Base / Prefetchable Memory Limit */
205 /* Force 64-bit addressing */
206 w1_bits = 0x00010001;
207 break;
208 default:
209 w1_bits = 0;
210 break;
211 }
212 return w1_bits;
213 }
214
thunder_pem_bridge_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)215 static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
216 int where, int size, u32 val)
217 {
218 struct pci_config_window *cfg = bus->sysdata;
219 struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
220 u64 write_val, read_val;
221 u64 where_aligned = where & ~3ull;
222 u32 mask = 0;
223
224
225 if (devfn != 0 || where >= 2048)
226 return PCIBIOS_DEVICE_NOT_FOUND;
227
228 /*
229 * 32-bit accesses only. If the write is for a size smaller
230 * than 32-bits, we must first read the 32-bit value and merge
231 * in the desired bits and then write the whole 32-bits back
232 * out.
233 */
234 switch (size) {
235 case 1:
236 writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
237 read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
238 read_val >>= 32;
239 mask = ~(0xff << (8 * (where & 3)));
240 read_val &= mask;
241 val = (val & 0xff) << (8 * (where & 3));
242 val |= (u32)read_val;
243 break;
244 case 2:
245 writeq(where_aligned, pem_pci->pem_reg_base + PEM_CFG_RD);
246 read_val = readq(pem_pci->pem_reg_base + PEM_CFG_RD);
247 read_val >>= 32;
248 mask = ~(0xffff << (8 * (where & 3)));
249 read_val &= mask;
250 val = (val & 0xffff) << (8 * (where & 3));
251 val |= (u32)read_val;
252 break;
253 default:
254 break;
255 }
256
257 /*
258 * By expanding the write width to 32 bits, we may
259 * inadvertently hit some W1C bits that were not intended to
260 * be written. Calculate the mask that must be applied to the
261 * data to be written to avoid these cases.
262 */
263 if (mask) {
264 u32 w1c_bits = thunder_pem_bridge_w1c_bits(where);
265
266 if (w1c_bits) {
267 mask &= w1c_bits;
268 val &= ~mask;
269 }
270 }
271
272 /*
273 * Some bits must be read-only with value of one. Since the
274 * access method allows these to be cleared if a zero is
275 * written, force them to one before writing.
276 */
277 val |= thunder_pem_bridge_w1_bits(where_aligned);
278
279 /*
280 * Low order bits are the config address, the high order 32
281 * bits are the data to be written.
282 */
283 write_val = (((u64)val) << 32) | where_aligned;
284 writeq(write_val, pem_pci->pem_reg_base + PEM_CFG_WR);
285 return PCIBIOS_SUCCESSFUL;
286 }
287
thunder_pem_config_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)288 static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
289 int where, int size, u32 val)
290 {
291 struct pci_config_window *cfg = bus->sysdata;
292
293 if (bus->number < cfg->busr.start ||
294 bus->number > cfg->busr.end)
295 return PCIBIOS_DEVICE_NOT_FOUND;
296 /*
297 * The first device on the bus is the PEM PCIe bridge.
298 * Special case its config access.
299 */
300 if (bus->number == cfg->busr.start)
301 return thunder_pem_bridge_write(bus, devfn, where, size, val);
302
303
304 return pci_generic_config_write(bus, devfn, where, size, val);
305 }
306
thunder_pem_init(struct device * dev,struct pci_config_window * cfg,struct resource * res_pem)307 static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg,
308 struct resource *res_pem)
309 {
310 struct thunder_pem_pci *pem_pci;
311 resource_size_t bar4_start;
312
313 pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
314 if (!pem_pci)
315 return -ENOMEM;
316
317 pem_pci->pem_reg_base = devm_ioremap(dev, res_pem->start, 0x10000);
318 if (!pem_pci->pem_reg_base)
319 return -ENOMEM;
320
321 /*
322 * The MSI-X BAR for the PEM and AER interrupts is located at
323 * a fixed offset from the PEM register base. Generate a
324 * fragment of the synthesized Enhanced Allocation capability
325 * structure here for the BAR.
326 */
327 bar4_start = res_pem->start + 0xf00000;
328 pem_pci->ea_entry[0] = lower_32_bits(bar4_start) | 2;
329 pem_pci->ea_entry[1] = lower_32_bits(res_pem->end - bar4_start) & ~3u;
330 pem_pci->ea_entry[2] = upper_32_bits(bar4_start);
331
332 cfg->priv = pem_pci;
333 return 0;
334 }
335
336 #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
337
338 #define PEM_RES_BASE 0x87e0c0000000ULL
339 #define PEM_NODE_MASK GENMASK_ULL(45, 44)
340 #define PEM_INDX_MASK GENMASK_ULL(26, 24)
341 #define PEM_MIN_DOM_IN_NODE 4
342 #define PEM_MAX_DOM_IN_NODE 10
343
thunder_pem_reserve_range(struct device * dev,int seg,struct resource * r)344 static void thunder_pem_reserve_range(struct device *dev, int seg,
345 struct resource *r)
346 {
347 resource_size_t start = r->start, end = r->end;
348 struct resource *res;
349 const char *regionid;
350
351 regionid = kasprintf(GFP_KERNEL, "PEM RC:%d", seg);
352 if (!regionid)
353 return;
354
355 res = request_mem_region(start, end - start + 1, regionid);
356 if (res)
357 res->flags &= ~IORESOURCE_BUSY;
358 else
359 kfree(regionid);
360
361 dev_info(dev, "%pR %s reserved\n", r,
362 res ? "has been" : "could not be");
363 }
364
thunder_pem_legacy_fw(struct acpi_pci_root * root,struct resource * res_pem)365 static void thunder_pem_legacy_fw(struct acpi_pci_root *root,
366 struct resource *res_pem)
367 {
368 int node = acpi_get_node(root->device->handle);
369 int index;
370
371 if (node == NUMA_NO_NODE)
372 node = 0;
373
374 index = root->segment - PEM_MIN_DOM_IN_NODE;
375 index -= node * PEM_MAX_DOM_IN_NODE;
376 res_pem->start = PEM_RES_BASE | FIELD_PREP(PEM_NODE_MASK, node) |
377 FIELD_PREP(PEM_INDX_MASK, index);
378 res_pem->flags = IORESOURCE_MEM;
379 }
380
thunder_pem_acpi_init(struct pci_config_window * cfg)381 static int thunder_pem_acpi_init(struct pci_config_window *cfg)
382 {
383 struct device *dev = cfg->parent;
384 struct acpi_device *adev = to_acpi_device(dev);
385 struct acpi_pci_root *root = acpi_driver_data(adev);
386 struct resource *res_pem;
387 int ret;
388
389 res_pem = devm_kzalloc(&adev->dev, sizeof(*res_pem), GFP_KERNEL);
390 if (!res_pem)
391 return -ENOMEM;
392
393 ret = acpi_get_rc_resources(dev, "CAVA02B", root->segment, res_pem);
394
395 /*
396 * If we fail to gather resources it means that we run with old
397 * FW where we need to calculate PEM-specific resources manually.
398 */
399 if (ret) {
400 thunder_pem_legacy_fw(root, res_pem);
401 /*
402 * Reserve 64K size PEM specific resources. The full 16M range
403 * size is required for thunder_pem_init() call.
404 */
405 res_pem->end = res_pem->start + SZ_64K - 1;
406 thunder_pem_reserve_range(dev, root->segment, res_pem);
407 res_pem->end = res_pem->start + SZ_16M - 1;
408
409 /* Reserve PCI configuration space as well. */
410 thunder_pem_reserve_range(dev, root->segment, &cfg->res);
411 }
412
413 return thunder_pem_init(dev, cfg, res_pem);
414 }
415
416 const struct pci_ecam_ops thunder_pem_ecam_ops = {
417 .bus_shift = THUNDER_PCIE_ECAM_BUS_SHIFT,
418 .init = thunder_pem_acpi_init,
419 .pci_ops = {
420 .map_bus = pci_ecam_map_bus,
421 .read = thunder_pem_config_read,
422 .write = thunder_pem_config_write,
423 }
424 };
425
426 #endif
427
428 #ifdef CONFIG_PCI_HOST_THUNDER_PEM
429
thunder_pem_platform_init(struct pci_config_window * cfg)430 static int thunder_pem_platform_init(struct pci_config_window *cfg)
431 {
432 struct device *dev = cfg->parent;
433 struct platform_device *pdev = to_platform_device(dev);
434 struct resource *res_pem;
435
436 if (!dev->of_node)
437 return -EINVAL;
438
439 /*
440 * The second register range is the PEM bridge to the PCIe
441 * bus. It has a different config access method than those
442 * devices behind the bridge.
443 */
444 res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
445 if (!res_pem) {
446 dev_err(dev, "missing \"reg[1]\"property\n");
447 return -EINVAL;
448 }
449
450 return thunder_pem_init(dev, cfg, res_pem);
451 }
452
453 static const struct pci_ecam_ops pci_thunder_pem_ops = {
454 .bus_shift = THUNDER_PCIE_ECAM_BUS_SHIFT,
455 .init = thunder_pem_platform_init,
456 .pci_ops = {
457 .map_bus = pci_ecam_map_bus,
458 .read = thunder_pem_config_read,
459 .write = thunder_pem_config_write,
460 }
461 };
462
463 static const struct of_device_id thunder_pem_of_match[] = {
464 {
465 .compatible = "cavium,pci-host-thunder-pem",
466 .data = &pci_thunder_pem_ops,
467 },
468 { },
469 };
470
471 static struct platform_driver thunder_pem_driver = {
472 .driver = {
473 .name = KBUILD_MODNAME,
474 .of_match_table = thunder_pem_of_match,
475 .suppress_bind_attrs = true,
476 },
477 .probe = pci_host_common_probe,
478 };
479 builtin_platform_driver(thunder_pem_driver);
480
481 #endif
482 #endif
483