1 /*
2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 */
14
15 #include <linux/kernel.h>
16 #include <linux/pci.h>
17 #include <linux/delay.h>
18 #include <linux/string.h>
19 #include <linux/init.h>
20 #include <linux/capability.h>
21 #include <linux/sched.h>
22 #include <linux/errno.h>
23 #include <linux/irq.h>
24 #include <linux/io.h>
25 #include <linux/uaccess.h>
26 #include <linux/export.h>
27
28 #include <asm/processor.h>
29 #include <asm/sections.h>
30 #include <asm/byteorder.h>
31 #include <asm/hv_driver.h>
32 #include <hv/drv_pcie_rc_intf.h>
33
34
35 /*
36 * Initialization flow and process
37 * -------------------------------
38 *
39 * This files contains the routines to search for PCI buses,
40 * enumerate the buses, and configure any attached devices.
41 *
42 * There are two entry points here:
43 * 1) tile_pci_init
44 * This sets up the pci_controller structs, and opens the
45 * FDs to the hypervisor. This is called from setup_arch() early
46 * in the boot process.
47 * 2) pcibios_init
48 * This probes the PCI bus(es) for any attached hardware. It's
49 * called by subsys_initcall. All of the real work is done by the
50 * generic Linux PCI layer.
51 *
52 */
53
54 static int pci_probe = 1;
55
56 /*
57 * This flag tells if the platform is TILEmpower that needs
58 * special configuration for the PLX switch chip.
59 */
60 int __write_once tile_plx_gen1;
61
62 static struct pci_controller controllers[TILE_NUM_PCIE];
63 static int num_controllers;
64 static int pci_scan_flags[TILE_NUM_PCIE];
65
66 static struct pci_ops tile_cfg_ops;
67
68
69 /*
70 * We don't need to worry about the alignment of resources.
71 */
pcibios_align_resource(void * data,const struct resource * res,resource_size_t size,resource_size_t align)72 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
73 resource_size_t size, resource_size_t align)
74 {
75 return res->start;
76 }
77 EXPORT_SYMBOL(pcibios_align_resource);
78
79 /*
80 * Open a FD to the hypervisor PCI device.
81 *
82 * controller_id is the controller number, config type is 0 or 1 for
83 * config0 or config1 operations.
84 */
tile_pcie_open(int controller_id,int config_type)85 static int tile_pcie_open(int controller_id, int config_type)
86 {
87 char filename[32];
88 int fd;
89
90 sprintf(filename, "pcie/%d/config%d", controller_id, config_type);
91
92 fd = hv_dev_open((HV_VirtAddr)filename, 0);
93
94 return fd;
95 }
96
97
98 /*
99 * Get the IRQ numbers from the HV and set up the handlers for them.
100 */
tile_init_irqs(int controller_id,struct pci_controller * controller)101 static int tile_init_irqs(int controller_id, struct pci_controller *controller)
102 {
103 char filename[32];
104 int fd;
105 int ret;
106 int x;
107 struct pcie_rc_config rc_config;
108
109 sprintf(filename, "pcie/%d/ctl", controller_id);
110 fd = hv_dev_open((HV_VirtAddr)filename, 0);
111 if (fd < 0) {
112 pr_err("PCI: hv_dev_open(%s) failed\n", filename);
113 return -1;
114 }
115 ret = hv_dev_pread(fd, 0, (HV_VirtAddr)(&rc_config),
116 sizeof(rc_config), PCIE_RC_CONFIG_MASK_OFF);
117 hv_dev_close(fd);
118 if (ret != sizeof(rc_config)) {
119 pr_err("PCI: wanted %zd bytes, got %d\n",
120 sizeof(rc_config), ret);
121 return -1;
122 }
123 /* Record irq_base so that we can map INTx to IRQ # later. */
124 controller->irq_base = rc_config.intr;
125
126 for (x = 0; x < 4; x++)
127 tile_irq_activate(rc_config.intr + x,
128 TILE_IRQ_HW_CLEAR);
129
130 if (rc_config.plx_gen1)
131 controller->plx_gen1 = 1;
132
133 return 0;
134 }
135
136 /*
137 * First initialization entry point, called from setup_arch().
138 *
139 * Find valid controllers and fill in pci_controller structs for each
140 * of them.
141 *
142 * Returns the number of controllers discovered.
143 */
tile_pci_init(void)144 int __init tile_pci_init(void)
145 {
146 int i;
147
148 if (!pci_probe) {
149 pr_info("PCI: disabled by boot argument\n");
150 return 0;
151 }
152
153 pr_info("PCI: Searching for controllers...\n");
154
155 /* Re-init number of PCIe controllers to support hot-plug feature. */
156 num_controllers = 0;
157
158 /* Do any configuration we need before using the PCIe */
159
160 for (i = 0; i < TILE_NUM_PCIE; i++) {
161 /*
162 * To see whether we need a real config op based on
163 * the results of pcibios_init(), to support PCIe hot-plug.
164 */
165 if (pci_scan_flags[i] == 0) {
166 int hv_cfg_fd0 = -1;
167 int hv_cfg_fd1 = -1;
168 int hv_mem_fd = -1;
169 char name[32];
170 struct pci_controller *controller;
171
172 /*
173 * Open the fd to the HV. If it fails then this
174 * device doesn't exist.
175 */
176 hv_cfg_fd0 = tile_pcie_open(i, 0);
177 if (hv_cfg_fd0 < 0)
178 continue;
179 hv_cfg_fd1 = tile_pcie_open(i, 1);
180 if (hv_cfg_fd1 < 0) {
181 pr_err("PCI: Couldn't open config fd to HV for controller %d\n",
182 i);
183 goto err_cont;
184 }
185
186 sprintf(name, "pcie/%d/mem", i);
187 hv_mem_fd = hv_dev_open((HV_VirtAddr)name, 0);
188 if (hv_mem_fd < 0) {
189 pr_err("PCI: Could not open mem fd to HV!\n");
190 goto err_cont;
191 }
192
193 pr_info("PCI: Found PCI controller #%d\n", i);
194
195 controller = &controllers[i];
196
197 controller->index = i;
198 controller->hv_cfg_fd[0] = hv_cfg_fd0;
199 controller->hv_cfg_fd[1] = hv_cfg_fd1;
200 controller->hv_mem_fd = hv_mem_fd;
201 controller->last_busno = 0xff;
202 controller->ops = &tile_cfg_ops;
203
204 num_controllers++;
205 continue;
206
207 err_cont:
208 if (hv_cfg_fd0 >= 0)
209 hv_dev_close(hv_cfg_fd0);
210 if (hv_cfg_fd1 >= 0)
211 hv_dev_close(hv_cfg_fd1);
212 if (hv_mem_fd >= 0)
213 hv_dev_close(hv_mem_fd);
214 continue;
215 }
216 }
217
218 /*
219 * Before using the PCIe, see if we need to do any platform-specific
220 * configuration, such as the PLX switch Gen 1 issue on TILEmpower.
221 */
222 for (i = 0; i < num_controllers; i++) {
223 struct pci_controller *controller = &controllers[i];
224
225 if (controller->plx_gen1)
226 tile_plx_gen1 = 1;
227 }
228
229 return num_controllers;
230 }
231
232 /*
233 * (pin - 1) converts from the PCI standard's [1:4] convention to
234 * a normal [0:3] range.
235 */
tile_map_irq(const struct pci_dev * dev,u8 slot,u8 pin)236 static int tile_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
237 {
238 struct pci_controller *controller =
239 (struct pci_controller *)dev->sysdata;
240 return (pin - 1) + controller->irq_base;
241 }
242
243
fixup_read_and_payload_sizes(void)244 static void fixup_read_and_payload_sizes(void)
245 {
246 struct pci_dev *dev = NULL;
247 int smallest_max_payload = 0x1; /* Tile maxes out at 256 bytes. */
248 int max_read_size = PCI_EXP_DEVCTL_READRQ_512B;
249 u16 new_values;
250
251 /* Scan for the smallest maximum payload size. */
252 for_each_pci_dev(dev) {
253 if (!pci_is_pcie(dev))
254 continue;
255
256 if (dev->pcie_mpss < smallest_max_payload)
257 smallest_max_payload = dev->pcie_mpss;
258 }
259
260 /* Now, set the max_payload_size for all devices to that value. */
261 new_values = max_read_size | (smallest_max_payload << 5);
262 for_each_pci_dev(dev)
263 pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
264 PCI_EXP_DEVCTL_PAYLOAD | PCI_EXP_DEVCTL_READRQ,
265 new_values);
266 }
267
268
269 /*
270 * Second PCI initialization entry point, called by subsys_initcall.
271 *
272 * The controllers have been set up by the time we get here, by a call to
273 * tile_pci_init.
274 */
pcibios_init(void)275 int __init pcibios_init(void)
276 {
277 int i;
278
279 pr_info("PCI: Probing PCI hardware\n");
280
281 /*
282 * Delay a bit in case devices aren't ready. Some devices are
283 * known to require at least 20ms here, but we use a more
284 * conservative value.
285 */
286 msleep(250);
287
288 /* Scan all of the recorded PCI controllers. */
289 for (i = 0; i < TILE_NUM_PCIE; i++) {
290 /*
291 * Do real pcibios init ops if the controller is initialized
292 * by tile_pci_init() successfully and not initialized by
293 * pcibios_init() yet to support PCIe hot-plug.
294 */
295 if (pci_scan_flags[i] == 0 && controllers[i].ops != NULL) {
296 struct pci_controller *controller = &controllers[i];
297 struct pci_bus *bus;
298 LIST_HEAD(resources);
299
300 if (tile_init_irqs(i, controller)) {
301 pr_err("PCI: Could not initialize IRQs\n");
302 continue;
303 }
304
305 pr_info("PCI: initializing controller #%d\n", i);
306
307 pci_add_resource(&resources, &ioport_resource);
308 pci_add_resource(&resources, &iomem_resource);
309 bus = pci_scan_root_bus(NULL, 0, controller->ops,
310 controller, &resources);
311 controller->root_bus = bus;
312 controller->last_busno = bus->busn_res.end;
313 }
314 }
315
316 /* Do machine dependent PCI interrupt routing */
317 pci_fixup_irqs(pci_common_swizzle, tile_map_irq);
318
319 /*
320 * This comes from the generic Linux PCI driver.
321 *
322 * It allocates all of the resources (I/O memory, etc)
323 * associated with the devices read in above.
324 */
325 pci_assign_unassigned_resources();
326
327 /* Configure the max_read_size and max_payload_size values. */
328 fixup_read_and_payload_sizes();
329
330 /* Record the I/O resources in the PCI controller structure. */
331 for (i = 0; i < TILE_NUM_PCIE; i++) {
332 /*
333 * Do real pcibios init ops if the controller is initialized
334 * by tile_pci_init() successfully and not initialized by
335 * pcibios_init() yet to support PCIe hot-plug.
336 */
337 if (pci_scan_flags[i] == 0 && controllers[i].ops != NULL) {
338 struct pci_bus *root_bus = controllers[i].root_bus;
339 struct pci_bus *next_bus;
340 struct pci_dev *dev;
341
342 pci_bus_add_devices(root_bus);
343
344 list_for_each_entry(dev, &root_bus->devices, bus_list) {
345 /*
346 * Find the PCI host controller, ie. the 1st
347 * bridge.
348 */
349 if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI &&
350 (PCI_SLOT(dev->devfn) == 0)) {
351 next_bus = dev->subordinate;
352 controllers[i].mem_resources[0] =
353 *next_bus->resource[0];
354 controllers[i].mem_resources[1] =
355 *next_bus->resource[1];
356 controllers[i].mem_resources[2] =
357 *next_bus->resource[2];
358
359 /* Setup flags. */
360 pci_scan_flags[i] = 1;
361
362 break;
363 }
364 }
365 }
366 }
367
368 return 0;
369 }
370 subsys_initcall(pcibios_init);
371
372 /*
373 * No bus fixups needed.
374 */
pcibios_fixup_bus(struct pci_bus * bus)375 void pcibios_fixup_bus(struct pci_bus *bus)
376 {
377 /* Nothing needs to be done. */
378 }
379
pcibios_set_master(struct pci_dev * dev)380 void pcibios_set_master(struct pci_dev *dev)
381 {
382 /* No special bus mastering setup handling. */
383 }
384
385 /* Process any "pci=" kernel boot arguments. */
pcibios_setup(char * str)386 char *__init pcibios_setup(char *str)
387 {
388 if (!strcmp(str, "off")) {
389 pci_probe = 0;
390 return NULL;
391 }
392 return str;
393 }
394
395 /*
396 * Enable memory and/or address decoding, as appropriate, for the
397 * device described by the 'dev' struct.
398 *
399 * This is called from the generic PCI layer, and can be called
400 * for bridges or endpoints.
401 */
pcibios_enable_device(struct pci_dev * dev,int mask)402 int pcibios_enable_device(struct pci_dev *dev, int mask)
403 {
404 u16 cmd, old_cmd;
405 u8 header_type;
406 int i;
407 struct resource *r;
408
409 pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
410
411 pci_read_config_word(dev, PCI_COMMAND, &cmd);
412 old_cmd = cmd;
413 if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
414 /*
415 * For bridges, we enable both memory and I/O decoding
416 * in call cases.
417 */
418 cmd |= PCI_COMMAND_IO;
419 cmd |= PCI_COMMAND_MEMORY;
420 } else {
421 /*
422 * For endpoints, we enable memory and/or I/O decoding
423 * only if they have a memory resource of that type.
424 */
425 for (i = 0; i < 6; i++) {
426 r = &dev->resource[i];
427 if (r->flags & IORESOURCE_UNSET) {
428 pr_err("PCI: Device %s not available because of resource collisions\n",
429 pci_name(dev));
430 return -EINVAL;
431 }
432 if (r->flags & IORESOURCE_IO)
433 cmd |= PCI_COMMAND_IO;
434 if (r->flags & IORESOURCE_MEM)
435 cmd |= PCI_COMMAND_MEMORY;
436 }
437 }
438
439 /*
440 * We only write the command if it changed.
441 */
442 if (cmd != old_cmd)
443 pci_write_config_word(dev, PCI_COMMAND, cmd);
444 return 0;
445 }
446
447 /****************************************************************
448 *
449 * Tile PCI config space read/write routines
450 *
451 ****************************************************************/
452
453 /*
454 * These are the normal read and write ops
455 * These are expanded with macros from pci_bus_read_config_byte() etc.
456 *
457 * devfn is the combined PCI slot & function.
458 *
459 * offset is in bytes, from the start of config space for the
460 * specified bus & slot.
461 */
462
tile_cfg_read(struct pci_bus * bus,unsigned int devfn,int offset,int size,u32 * val)463 static int tile_cfg_read(struct pci_bus *bus, unsigned int devfn, int offset,
464 int size, u32 *val)
465 {
466 struct pci_controller *controller = bus->sysdata;
467 int busnum = bus->number & 0xff;
468 int slot = (devfn >> 3) & 0x1f;
469 int function = devfn & 0x7;
470 u32 addr;
471 int config_mode = 1;
472
473 /*
474 * There is no bridge between the Tile and bus 0, so we
475 * use config0 to talk to bus 0.
476 *
477 * If we're talking to a bus other than zero then we
478 * must have found a bridge.
479 */
480 if (busnum == 0) {
481 /*
482 * We fake an empty slot for (busnum == 0) && (slot > 0),
483 * since there is only one slot on bus 0.
484 */
485 if (slot) {
486 *val = 0xFFFFFFFF;
487 return 0;
488 }
489 config_mode = 0;
490 }
491
492 addr = busnum << 20; /* Bus in 27:20 */
493 addr |= slot << 15; /* Slot (device) in 19:15 */
494 addr |= function << 12; /* Function is in 14:12 */
495 addr |= (offset & 0xFFF); /* byte address in 0:11 */
496
497 return hv_dev_pread(controller->hv_cfg_fd[config_mode], 0,
498 (HV_VirtAddr)(val), size, addr);
499 }
500
501
502 /*
503 * See tile_cfg_read() for relevant comments.
504 * Note that "val" is the value to write, not a pointer to that value.
505 */
tile_cfg_write(struct pci_bus * bus,unsigned int devfn,int offset,int size,u32 val)506 static int tile_cfg_write(struct pci_bus *bus, unsigned int devfn, int offset,
507 int size, u32 val)
508 {
509 struct pci_controller *controller = bus->sysdata;
510 int busnum = bus->number & 0xff;
511 int slot = (devfn >> 3) & 0x1f;
512 int function = devfn & 0x7;
513 u32 addr;
514 int config_mode = 1;
515 HV_VirtAddr valp = (HV_VirtAddr)&val;
516
517 /*
518 * For bus 0 slot 0 we use config 0 accesses.
519 */
520 if (busnum == 0) {
521 /*
522 * We fake an empty slot for (busnum == 0) && (slot > 0),
523 * since there is only one slot on bus 0.
524 */
525 if (slot)
526 return 0;
527 config_mode = 0;
528 }
529
530 addr = busnum << 20; /* Bus in 27:20 */
531 addr |= slot << 15; /* Slot (device) in 19:15 */
532 addr |= function << 12; /* Function is in 14:12 */
533 addr |= (offset & 0xFFF); /* byte address in 0:11 */
534
535 #ifdef __BIG_ENDIAN
536 /* Point to the correct part of the 32-bit "val". */
537 valp += 4 - size;
538 #endif
539
540 return hv_dev_pwrite(controller->hv_cfg_fd[config_mode], 0,
541 valp, size, addr);
542 }
543
544
545 static struct pci_ops tile_cfg_ops = {
546 .read = tile_cfg_read,
547 .write = tile_cfg_write,
548 };
549
550
551 /*
552 * In the following, each PCI controller's mem_resources[1]
553 * represents its (non-prefetchable) PCI memory resource.
554 * mem_resources[0] and mem_resources[2] refer to its PCI I/O and
555 * prefetchable PCI memory resources, respectively.
556 * For more details, see pci_setup_bridge() in setup-bus.c.
557 * By comparing the target PCI memory address against the
558 * end address of controller 0, we can determine the controller
559 * that should accept the PCI memory access.
560 */
561 #define TILE_READ(size, type) \
562 type _tile_read##size(unsigned long addr) \
563 { \
564 type val; \
565 int idx = 0; \
566 if (addr > controllers[0].mem_resources[1].end && \
567 addr > controllers[0].mem_resources[2].end) \
568 idx = 1; \
569 if (hv_dev_pread(controllers[idx].hv_mem_fd, 0, \
570 (HV_VirtAddr)(&val), sizeof(type), addr)) \
571 pr_err("PCI: read %zd bytes at 0x%lX failed\n", \
572 sizeof(type), addr); \
573 return val; \
574 } \
575 EXPORT_SYMBOL(_tile_read##size)
576
577 TILE_READ(b, u8);
578 TILE_READ(w, u16);
579 TILE_READ(l, u32);
580 TILE_READ(q, u64);
581
582 #define TILE_WRITE(size, type) \
583 void _tile_write##size(type val, unsigned long addr) \
584 { \
585 int idx = 0; \
586 if (addr > controllers[0].mem_resources[1].end && \
587 addr > controllers[0].mem_resources[2].end) \
588 idx = 1; \
589 if (hv_dev_pwrite(controllers[idx].hv_mem_fd, 0, \
590 (HV_VirtAddr)(&val), sizeof(type), addr)) \
591 pr_err("PCI: write %zd bytes at 0x%lX failed\n", \
592 sizeof(type), addr); \
593 } \
594 EXPORT_SYMBOL(_tile_write##size)
595
596 TILE_WRITE(b, u8);
597 TILE_WRITE(w, u16);
598 TILE_WRITE(l, u32);
599 TILE_WRITE(q, u64);
600