1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/arm/kernel/bios32.c
4 *
5 * PCI bios-type initialisation for PCI machines
6 *
7 * Bits taken from various places.
8 */
9 #include <linux/export.h>
10 #include <linux/kernel.h>
11 #include <linux/pci.h>
12 #include <linux/slab.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15
16 #include <asm/mach-types.h>
17 #include <asm/mach/map.h>
18 #include <asm/mach/pci.h>
19
20 static int debug_pci;
21
22 /*
23 * We can't use pci_get_device() here since we are
24 * called from interrupt context.
25 */
26 static void pcibios_bus_report_status(struct pci_bus *bus, u_int status_mask, int warn)
27 {
28 struct pci_dev *dev;
29
30 list_for_each_entry(dev, &bus->devices, bus_list) {
31 u16 status;
32
33 /*
34 * ignore host bridge - we handle
35 * that separately
36 */
37 if (dev->bus->number == 0 && dev->devfn == 0)
38 continue;
39
40 pci_read_config_word(dev, PCI_STATUS, &status);
41 if (status == 0xffff)
42 continue;
43
44 if ((status & status_mask) == 0)
45 continue;
46
47 /* clear the status errors */
48 pci_write_config_word(dev, PCI_STATUS, status & status_mask);
49
50 if (warn)
51 printk("(%s: %04X) ", pci_name(dev), status);
52 }
53
54 list_for_each_entry(dev, &bus->devices, bus_list)
55 if (dev->subordinate)
56 pcibios_bus_report_status(dev->subordinate, status_mask, warn);
57 }
58
59 void pcibios_report_status(u_int status_mask, int warn)
60 {
61 struct pci_bus *bus;
62
63 list_for_each_entry(bus, &pci_root_buses, node)
64 pcibios_bus_report_status(bus, status_mask, warn);
65 }
66
67 /*
68 * We don't use this to fix the device, but initialisation of it.
69 * It's not the correct use for this, but it works.
70 * Note that the arbiter/ISA bridge appears to be buggy, specifically in
71 * the following area:
72 * 1. park on CPU
73 * 2. ISA bridge ping-pong
74 * 3. ISA bridge master handling of target RETRY
75 *
76 * Bug 3 is responsible for the sound DMA grinding to a halt. We now
77 * live with bug 2.
78 */
79 static void pci_fixup_83c553(struct pci_dev *dev)
80 {
81 /*
82 * Set memory region to start at address 0, and enable IO
83 */
84 pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, PCI_BASE_ADDRESS_SPACE_MEMORY);
85 pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_IO);
86
87 dev->resource[0].end -= dev->resource[0].start;
88 dev->resource[0].start = 0;
89
90 /*
91 * All memory requests from ISA to be channelled to PCI
92 */
93 pci_write_config_byte(dev, 0x48, 0xff);
94
95 /*
96 * Enable ping-pong on bus master to ISA bridge transactions.
97 * This improves the sound DMA substantially. The fixed
98 * priority arbiter also helps (see below).
99 */
100 pci_write_config_byte(dev, 0x42, 0x01);
101
102 /*
103 * Enable PCI retry
104 */
105 pci_write_config_byte(dev, 0x40, 0x22);
106
107 /*
108 * We used to set the arbiter to "park on last master" (bit
109 * 1 set), but unfortunately the CyberPro does not park the
110 * bus. We must therefore park on CPU. Unfortunately, this
111 * may trigger yet another bug in the 553.
112 */
113 pci_write_config_byte(dev, 0x83, 0x02);
114
115 /*
116 * Make the ISA DMA request lowest priority, and disable
117 * rotating priorities completely.
118 */
119 pci_write_config_byte(dev, 0x80, 0x11);
120 pci_write_config_byte(dev, 0x81, 0x00);
121
122 /*
123 * Route INTA input to IRQ 11, and set IRQ11 to be level
124 * sensitive.
125 */
126 pci_write_config_word(dev, 0x44, 0xb000);
127 outb(0x08, 0x4d1);
128 }
129 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_83C553, pci_fixup_83c553);
130
131 static void pci_fixup_unassign(struct pci_dev *dev)
132 {
133 dev->resource[0].end -= dev->resource[0].start;
134 dev->resource[0].start = 0;
135 }
136 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND2, PCI_DEVICE_ID_WINBOND2_89C940F, pci_fixup_unassign);
137
138 /*
139 * Prevent the PCI layer from seeing the resources allocated to this device
140 * if it is the host bridge by marking it as such. These resources are of
141 * no consequence to the PCI layer (they are handled elsewhere).
142 */
143 static void pci_fixup_dec21285(struct pci_dev *dev)
144 {
145 if (dev->devfn == 0) {
146 struct resource *r;
147
148 dev->class &= 0xff;
149 dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
150 pci_dev_for_each_resource(dev, r) {
151 r->start = 0;
152 r->end = 0;
153 r->flags = 0;
154 }
155 }
156 }
157 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21285, pci_fixup_dec21285);
158
159 /*
160 * PCI IDE controllers use non-standard I/O port decoding, respect it.
161 */
162 static void pci_fixup_ide_bases(struct pci_dev *dev)
163 {
164 struct resource *r;
165
166 if ((dev->class >> 8) != PCI_CLASS_STORAGE_IDE)
167 return;
168
169 pci_dev_for_each_resource(dev, r) {
170 if ((r->start & ~0x80) == 0x374) {
171 r->start |= 2;
172 r->end = r->start;
173 }
174 }
175 }
176 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_ide_bases);
177
178 /*
179 * Put the DEC21142 to sleep
180 */
181 static void pci_fixup_dec21142(struct pci_dev *dev)
182 {
183 pci_write_config_dword(dev, 0x40, 0x80000000);
184 }
185 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21142, pci_fixup_dec21142);
186
187 /*
188 * The CY82C693 needs some rather major fixups to ensure that it does
189 * the right thing. Idea from the Alpha people, with a few additions.
190 *
191 * We ensure that the IDE base registers are set to 1f0/3f4 for the
192 * primary bus, and 170/374 for the secondary bus. Also, hide them
193 * from the PCI subsystem view as well so we won't try to perform
194 * our own auto-configuration on them.
195 *
196 * In addition, we ensure that the PCI IDE interrupts are routed to
197 * IRQ 14 and IRQ 15 respectively.
198 *
199 * The above gets us to a point where the IDE on this device is
200 * functional. However, The CY82C693U _does not work_ in bus
201 * master mode without locking the PCI bus solid.
202 */
203 static void pci_fixup_cy82c693(struct pci_dev *dev)
204 {
205 if ((dev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
206 u32 base0, base1;
207
208 if (dev->class & 0x80) { /* primary */
209 base0 = 0x1f0;
210 base1 = 0x3f4;
211 } else { /* secondary */
212 base0 = 0x170;
213 base1 = 0x374;
214 }
215
216 pci_write_config_dword(dev, PCI_BASE_ADDRESS_0,
217 base0 | PCI_BASE_ADDRESS_SPACE_IO);
218 pci_write_config_dword(dev, PCI_BASE_ADDRESS_1,
219 base1 | PCI_BASE_ADDRESS_SPACE_IO);
220
221 dev->resource[0].start = 0;
222 dev->resource[0].end = 0;
223 dev->resource[0].flags = 0;
224
225 dev->resource[1].start = 0;
226 dev->resource[1].end = 0;
227 dev->resource[1].flags = 0;
228 } else if (PCI_FUNC(dev->devfn) == 0) {
229 /*
230 * Setup IDE IRQ routing.
231 */
232 pci_write_config_byte(dev, 0x4b, 14);
233 pci_write_config_byte(dev, 0x4c, 15);
234
235 /*
236 * Disable FREQACK handshake, enable USB.
237 */
238 pci_write_config_byte(dev, 0x4d, 0x41);
239
240 /*
241 * Enable PCI retry, and PCI post-write buffer.
242 */
243 pci_write_config_byte(dev, 0x44, 0x17);
244
245 /*
246 * Enable ISA master and DMA post write buffering.
247 */
248 pci_write_config_byte(dev, 0x45, 0x03);
249 }
250 }
251 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CONTAQ, PCI_DEVICE_ID_CONTAQ_82C693, pci_fixup_cy82c693);
252
253 /*
254 * If the bus contains any of these devices, then we must not turn on
255 * parity checking of any kind. Currently this is CyberPro 20x0 only.
256 */
257 static inline int pdev_bad_for_parity(struct pci_dev *dev)
258 {
259 return ((dev->vendor == PCI_VENDOR_ID_INTERG &&
260 (dev->device == PCI_DEVICE_ID_INTERG_2000 ||
261 dev->device == PCI_DEVICE_ID_INTERG_2010)) ||
262 (dev->vendor == PCI_VENDOR_ID_ITE &&
263 dev->device == PCI_DEVICE_ID_ITE_8152));
264
265 }
266
267 /*
268 * pcibios_fixup_bus - Called after each bus is probed,
269 * but before its children are examined.
270 */
271 void pcibios_fixup_bus(struct pci_bus *bus)
272 {
273 struct pci_dev *dev;
274 u16 features = PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_FAST_BACK;
275
276 /*
277 * Walk the devices on this bus, working out what we can
278 * and can't support.
279 */
280 list_for_each_entry(dev, &bus->devices, bus_list) {
281 u16 status;
282
283 pci_read_config_word(dev, PCI_STATUS, &status);
284
285 /*
286 * If any device on this bus does not support fast back
287 * to back transfers, then the bus as a whole is not able
288 * to support them. Having fast back to back transfers
289 * on saves us one PCI cycle per transaction.
290 */
291 if (!(status & PCI_STATUS_FAST_BACK))
292 features &= ~PCI_COMMAND_FAST_BACK;
293
294 if (pdev_bad_for_parity(dev))
295 features &= ~(PCI_COMMAND_SERR | PCI_COMMAND_PARITY);
296
297 switch (dev->class >> 8) {
298 case PCI_CLASS_BRIDGE_PCI:
299 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &status);
300 status |= PCI_BRIDGE_CTL_PARITY|PCI_BRIDGE_CTL_MASTER_ABORT;
301 status &= ~(PCI_BRIDGE_CTL_BUS_RESET|PCI_BRIDGE_CTL_FAST_BACK);
302 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, status);
303 break;
304
305 case PCI_CLASS_BRIDGE_CARDBUS:
306 pci_read_config_word(dev, PCI_CB_BRIDGE_CONTROL, &status);
307 status |= PCI_CB_BRIDGE_CTL_PARITY|PCI_CB_BRIDGE_CTL_MASTER_ABORT;
308 pci_write_config_word(dev, PCI_CB_BRIDGE_CONTROL, status);
309 break;
310 }
311 }
312
313 /*
314 * Now walk the devices again, this time setting them up.
315 */
316 list_for_each_entry(dev, &bus->devices, bus_list) {
317 u16 cmd;
318
319 pci_read_config_word(dev, PCI_COMMAND, &cmd);
320 cmd |= features;
321 pci_write_config_word(dev, PCI_COMMAND, cmd);
322
323 pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE,
324 L1_CACHE_BYTES >> 2);
325 }
326
327 /*
328 * Propagate the flags to the PCI bridge.
329 */
330 if (bus->self && bus->self->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
331 if (features & PCI_COMMAND_FAST_BACK)
332 bus->bridge_ctl |= PCI_BRIDGE_CTL_FAST_BACK;
333 if (features & PCI_COMMAND_PARITY)
334 bus->bridge_ctl |= PCI_BRIDGE_CTL_PARITY;
335 }
336
337 /*
338 * Report what we did for this bus
339 */
340 pr_info("PCI: bus%d: Fast back to back transfers %sabled\n",
341 bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : "dis");
342 }
343 EXPORT_SYMBOL(pcibios_fixup_bus);
344
345 /*
346 * Swizzle the device pin each time we cross a bridge. If a platform does
347 * not provide a swizzle function, we perform the standard PCI swizzling.
348 *
349 * The default swizzling walks up the bus tree one level at a time, applying
350 * the standard swizzle function at each step, stopping when it finds the PCI
351 * root bus. This will return the slot number of the bridge device on the
352 * root bus and the interrupt pin on that device which should correspond
353 * with the downstream device interrupt.
354 *
355 * Platforms may override this, in which case the slot and pin returned
356 * depend entirely on the platform code. However, please note that the
357 * PCI standard swizzle is implemented on plug-in cards and Cardbus based
358 * PCI extenders, so it can not be ignored.
359 */
360 static u8 pcibios_swizzle(struct pci_dev *dev, u8 *pin)
361 {
362 struct pci_sys_data *sys = dev->sysdata;
363 int slot, oldpin = *pin;
364
365 if (sys->swizzle)
366 slot = sys->swizzle(dev, pin);
367 else
368 slot = pci_common_swizzle(dev, pin);
369
370 if (debug_pci)
371 printk("PCI: %s swizzling pin %d => pin %d slot %d\n",
372 pci_name(dev), oldpin, *pin, slot);
373
374 return slot;
375 }
376
377 /*
378 * Map a slot/pin to an IRQ.
379 */
380 static int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
381 {
382 struct pci_sys_data *sys = dev->sysdata;
383 int irq = -1;
384
385 if (sys->map_irq)
386 irq = sys->map_irq(dev, slot, pin);
387
388 if (debug_pci)
389 printk("PCI: %s mapping slot %d pin %d => irq %d\n",
390 pci_name(dev), slot, pin, irq);
391
392 return irq;
393 }
394
395 static int pcibios_init_resource(int busnr, struct pci_sys_data *sys)
396 {
397 int ret;
398 struct resource_entry *window;
399
400 if (list_empty(&sys->resources)) {
401 pci_add_resource_offset(&sys->resources,
402 &iomem_resource, sys->mem_offset);
403 }
404
405 resource_list_for_each_entry(window, &sys->resources)
406 if (resource_type(window->res) == IORESOURCE_IO)
407 return 0;
408
409 sys->io_res.start = (busnr * SZ_64K) ? : pcibios_min_io;
410 sys->io_res.end = (busnr + 1) * SZ_64K - 1;
411 sys->io_res.flags = IORESOURCE_IO;
412 sys->io_res.name = sys->io_res_name;
413 sprintf(sys->io_res_name, "PCI%d I/O", busnr);
414
415 ret = request_resource(&ioport_resource, &sys->io_res);
416 if (ret) {
417 pr_err("PCI: unable to allocate I/O port region (%d)\n", ret);
418 return ret;
419 }
420 pci_add_resource_offset(&sys->resources, &sys->io_res,
421 sys->io_offset);
422
423 return 0;
424 }
425
426 static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
427 struct list_head *head)
428 {
429 struct pci_sys_data *sys = NULL;
430 int ret;
431 int nr, busnr;
432
433 for (nr = busnr = 0; nr < hw->nr_controllers; nr++) {
434 struct pci_host_bridge *bridge;
435
436 bridge = pci_alloc_host_bridge(sizeof(struct pci_sys_data));
437 if (WARN(!bridge, "PCI: unable to allocate bridge!"))
438 break;
439
440 sys = pci_host_bridge_priv(bridge);
441
442 sys->busnr = busnr;
443 sys->swizzle = hw->swizzle;
444 sys->map_irq = hw->map_irq;
445 INIT_LIST_HEAD(&sys->resources);
446
447 if (hw->private_data)
448 sys->private_data = hw->private_data[nr];
449
450 ret = hw->setup(nr, sys);
451
452 if (ret > 0) {
453
454 ret = pcibios_init_resource(nr, sys);
455 if (ret) {
456 pci_free_host_bridge(bridge);
457 break;
458 }
459
460 bridge->map_irq = pcibios_map_irq;
461 bridge->swizzle_irq = pcibios_swizzle;
462
463 if (hw->scan)
464 ret = hw->scan(nr, bridge);
465 else {
466 list_splice_init(&sys->resources,
467 &bridge->windows);
468 bridge->dev.parent = parent;
469 bridge->sysdata = sys;
470 bridge->busnr = sys->busnr;
471 bridge->ops = hw->ops;
472
473 ret = pci_scan_root_bus_bridge(bridge);
474 }
475
476 if (WARN(ret < 0, "PCI: unable to scan bus!")) {
477 pci_free_host_bridge(bridge);
478 break;
479 }
480
481 sys->bus = bridge->bus;
482
483 busnr = sys->bus->busn_res.end + 1;
484
485 list_add(&sys->node, head);
486 } else {
487 pci_free_host_bridge(bridge);
488 if (ret < 0)
489 break;
490 }
491 }
492 }
493
494 void pci_common_init_dev(struct device *parent, struct hw_pci *hw)
495 {
496 struct pci_sys_data *sys;
497 LIST_HEAD(head);
498
499 pci_add_flags(PCI_REASSIGN_ALL_BUS);
500 if (hw->preinit)
501 hw->preinit();
502 pcibios_init_hw(parent, hw, &head);
503 if (hw->postinit)
504 hw->postinit();
505
506 list_for_each_entry(sys, &head, node) {
507 struct pci_bus *bus = sys->bus;
508
509 /*
510 * We insert PCI resources into the iomem_resource and
511 * ioport_resource trees in either pci_bus_claim_resources()
512 * or pci_bus_assign_resources().
513 */
514 if (pci_has_flag(PCI_PROBE_ONLY)) {
515 pci_bus_claim_resources(bus);
516 } else {
517 struct pci_bus *child;
518
519 pci_bus_size_bridges(bus);
520 pci_bus_assign_resources(bus);
521
522 list_for_each_entry(child, &bus->children, node)
523 pcie_bus_configure_settings(child);
524 }
525
526 pci_bus_add_devices(bus);
527 }
528 }
529
530 #ifndef CONFIG_PCI_HOST_ITE8152
531 void pcibios_set_master(struct pci_dev *dev)
532 {
533 /* No special bus mastering setup handling */
534 }
535 #endif
536
537 char * __init pcibios_setup(char *str)
538 {
539 if (!strcmp(str, "debug")) {
540 debug_pci = 1;
541 return NULL;
542 }
543 return str;
544 }
545
546 /*
547 * From arch/i386/kernel/pci-i386.c:
548 *
549 * We need to avoid collisions with `mirrored' VGA ports
550 * and other strange ISA hardware, so we always want the
551 * addresses to be allocated in the 0x000-0x0ff region
552 * modulo 0x400.
553 *
554 * Why? Because some silly external IO cards only decode
555 * the low 10 bits of the IO address. The 0x00-0xff region
556 * is reserved for motherboard devices that decode all 16
557 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
558 * but we want to try to avoid allocating at 0x2900-0x2bff
559 * which might be mirrored at 0x0100-0x03ff..
560 */
561 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
562 resource_size_t size, resource_size_t align)
563 {
564 struct pci_dev *dev = data;
565 resource_size_t start = res->start;
566 struct pci_host_bridge *host_bridge;
567
568 if (res->flags & IORESOURCE_IO && start & 0x300)
569 start = (start + 0x3ff) & ~0x3ff;
570
571 start = (start + align - 1) & ~(align - 1);
572
573 host_bridge = pci_find_host_bridge(dev->bus);
574
575 if (host_bridge->align_resource)
576 return host_bridge->align_resource(dev, res,
577 start, size, align);
578
579 return start;
580 }
581
582 void __init pci_map_io_early(unsigned long pfn)
583 {
584 struct map_desc pci_io_desc = {
585 .virtual = PCI_IO_VIRT_BASE,
586 .type = MT_DEVICE,
587 .length = SZ_64K,
588 };
589
590 pci_io_desc.pfn = pfn;
591 iotable_init(&pci_io_desc, 1);
592 }
593
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