1 /*
2  * Support PCI/PCIe on PowerNV platforms
3  *
4  * Currently supports only P5IOC2
5  *
6  * Copyright 2011 Benjamin Herrenschmidt, IBM Corp.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * as published by the Free Software Foundation; either version
11  * 2 of the License, or (at your option) any later version.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/pci.h>
16 #include <linux/delay.h>
17 #include <linux/string.h>
18 #include <linux/init.h>
19 #include <linux/bootmem.h>
20 #include <linux/irq.h>
21 #include <linux/io.h>
22 #include <linux/msi.h>
23 
24 #include <asm/sections.h>
25 #include <asm/io.h>
26 #include <asm/prom.h>
27 #include <asm/pci-bridge.h>
28 #include <asm/machdep.h>
29 #include <asm/msi_bitmap.h>
30 #include <asm/ppc-pci.h>
31 #include <asm/opal.h>
32 #include <asm/iommu.h>
33 #include <asm/tce.h>
34 #include <asm/firmware.h>
35 
36 #include "powernv.h"
37 #include "pci.h"
38 
39 /* Delay in usec */
40 #define PCI_RESET_DELAY_US	3000000
41 
42 #define cfg_dbg(fmt...)	do { } while(0)
43 //#define cfg_dbg(fmt...)	printk(fmt)
44 
45 #ifdef CONFIG_PCI_MSI
46 static int pnv_msi_check_device(struct pci_dev* pdev, int nvec, int type)
47 {
48 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
49 	struct pnv_phb *phb = hose->private_data;
50 
51 	return (phb && phb->msi_bmp.bitmap) ? 0 : -ENODEV;
52 }
53 
54 static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
55 {
56 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
57 	struct pnv_phb *phb = hose->private_data;
58 	struct msi_desc *entry;
59 	struct msi_msg msg;
60 	int hwirq;
61 	unsigned int virq;
62 	int rc;
63 
64 	if (WARN_ON(!phb))
65 		return -ENODEV;
66 
67 	list_for_each_entry(entry, &pdev->msi_list, list) {
68 		if (!entry->msi_attrib.is_64 && !phb->msi32_support) {
69 			pr_warn("%s: Supports only 64-bit MSIs\n",
70 				pci_name(pdev));
71 			return -ENXIO;
72 		}
73 		hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, 1);
74 		if (hwirq < 0) {
75 			pr_warn("%s: Failed to find a free MSI\n",
76 				pci_name(pdev));
77 			return -ENOSPC;
78 		}
79 		virq = irq_create_mapping(NULL, phb->msi_base + hwirq);
80 		if (virq == NO_IRQ) {
81 			pr_warn("%s: Failed to map MSI to linux irq\n",
82 				pci_name(pdev));
83 			msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq, 1);
84 			return -ENOMEM;
85 		}
86 		rc = phb->msi_setup(phb, pdev, phb->msi_base + hwirq,
87 				    virq, entry->msi_attrib.is_64, &msg);
88 		if (rc) {
89 			pr_warn("%s: Failed to setup MSI\n", pci_name(pdev));
90 			irq_dispose_mapping(virq);
91 			msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq, 1);
92 			return rc;
93 		}
94 		irq_set_msi_desc(virq, entry);
95 		write_msi_msg(virq, &msg);
96 	}
97 	return 0;
98 }
99 
100 static void pnv_teardown_msi_irqs(struct pci_dev *pdev)
101 {
102 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
103 	struct pnv_phb *phb = hose->private_data;
104 	struct msi_desc *entry;
105 
106 	if (WARN_ON(!phb))
107 		return;
108 
109 	list_for_each_entry(entry, &pdev->msi_list, list) {
110 		if (entry->irq == NO_IRQ)
111 			continue;
112 		irq_set_msi_desc(entry->irq, NULL);
113 		msi_bitmap_free_hwirqs(&phb->msi_bmp,
114 			virq_to_hw(entry->irq) - phb->msi_base, 1);
115 		irq_dispose_mapping(entry->irq);
116 	}
117 }
118 #endif /* CONFIG_PCI_MSI */
119 
120 static void pnv_pci_dump_p7ioc_diag_data(struct pnv_phb *phb)
121 {
122 	struct OpalIoP7IOCPhbErrorData *data = &phb->diag.p7ioc;
123 	int i;
124 
125 	pr_info("PHB %d diagnostic data:\n", phb->hose->global_number);
126 
127 	pr_info("  brdgCtl              = 0x%08x\n", data->brdgCtl);
128 
129 	pr_info("  portStatusReg        = 0x%08x\n", data->portStatusReg);
130 	pr_info("  rootCmplxStatus      = 0x%08x\n", data->rootCmplxStatus);
131 	pr_info("  busAgentStatus       = 0x%08x\n", data->busAgentStatus);
132 
133 	pr_info("  deviceStatus         = 0x%08x\n", data->deviceStatus);
134 	pr_info("  slotStatus           = 0x%08x\n", data->slotStatus);
135 	pr_info("  linkStatus           = 0x%08x\n", data->linkStatus);
136 	pr_info("  devCmdStatus         = 0x%08x\n", data->devCmdStatus);
137 	pr_info("  devSecStatus         = 0x%08x\n", data->devSecStatus);
138 
139 	pr_info("  rootErrorStatus      = 0x%08x\n", data->rootErrorStatus);
140 	pr_info("  uncorrErrorStatus    = 0x%08x\n", data->uncorrErrorStatus);
141 	pr_info("  corrErrorStatus      = 0x%08x\n", data->corrErrorStatus);
142 	pr_info("  tlpHdr1              = 0x%08x\n", data->tlpHdr1);
143 	pr_info("  tlpHdr2              = 0x%08x\n", data->tlpHdr2);
144 	pr_info("  tlpHdr3              = 0x%08x\n", data->tlpHdr3);
145 	pr_info("  tlpHdr4              = 0x%08x\n", data->tlpHdr4);
146 	pr_info("  sourceId             = 0x%08x\n", data->sourceId);
147 
148 	pr_info("  errorClass           = 0x%016llx\n", data->errorClass);
149 	pr_info("  correlator           = 0x%016llx\n", data->correlator);
150 
151 	pr_info("  p7iocPlssr           = 0x%016llx\n", data->p7iocPlssr);
152 	pr_info("  p7iocCsr             = 0x%016llx\n", data->p7iocCsr);
153 	pr_info("  lemFir               = 0x%016llx\n", data->lemFir);
154 	pr_info("  lemErrorMask         = 0x%016llx\n", data->lemErrorMask);
155 	pr_info("  lemWOF               = 0x%016llx\n", data->lemWOF);
156 	pr_info("  phbErrorStatus       = 0x%016llx\n", data->phbErrorStatus);
157 	pr_info("  phbFirstErrorStatus  = 0x%016llx\n", data->phbFirstErrorStatus);
158 	pr_info("  phbErrorLog0         = 0x%016llx\n", data->phbErrorLog0);
159 	pr_info("  phbErrorLog1         = 0x%016llx\n", data->phbErrorLog1);
160 	pr_info("  mmioErrorStatus      = 0x%016llx\n", data->mmioErrorStatus);
161 	pr_info("  mmioFirstErrorStatus = 0x%016llx\n", data->mmioFirstErrorStatus);
162 	pr_info("  mmioErrorLog0        = 0x%016llx\n", data->mmioErrorLog0);
163 	pr_info("  mmioErrorLog1        = 0x%016llx\n", data->mmioErrorLog1);
164 	pr_info("  dma0ErrorStatus      = 0x%016llx\n", data->dma0ErrorStatus);
165 	pr_info("  dma0FirstErrorStatus = 0x%016llx\n", data->dma0FirstErrorStatus);
166 	pr_info("  dma0ErrorLog0        = 0x%016llx\n", data->dma0ErrorLog0);
167 	pr_info("  dma0ErrorLog1        = 0x%016llx\n", data->dma0ErrorLog1);
168 	pr_info("  dma1ErrorStatus      = 0x%016llx\n", data->dma1ErrorStatus);
169 	pr_info("  dma1FirstErrorStatus = 0x%016llx\n", data->dma1FirstErrorStatus);
170 	pr_info("  dma1ErrorLog0        = 0x%016llx\n", data->dma1ErrorLog0);
171 	pr_info("  dma1ErrorLog1        = 0x%016llx\n", data->dma1ErrorLog1);
172 
173 	for (i = 0; i < OPAL_P7IOC_NUM_PEST_REGS; i++) {
174 		if ((data->pestA[i] >> 63) == 0 &&
175 		    (data->pestB[i] >> 63) == 0)
176 			continue;
177 		pr_info("  PE[%3d] PESTA        = 0x%016llx\n", i, data->pestA[i]);
178 		pr_info("          PESTB        = 0x%016llx\n", data->pestB[i]);
179 	}
180 }
181 
182 static void pnv_pci_dump_phb_diag_data(struct pnv_phb *phb)
183 {
184 	switch(phb->model) {
185 	case PNV_PHB_MODEL_P7IOC:
186 		pnv_pci_dump_p7ioc_diag_data(phb);
187 		break;
188 	default:
189 		pr_warning("PCI %d: Can't decode this PHB diag data\n",
190 			   phb->hose->global_number);
191 	}
192 }
193 
194 static void pnv_pci_handle_eeh_config(struct pnv_phb *phb, u32 pe_no)
195 {
196 	unsigned long flags, rc;
197 	int has_diag;
198 
199 	spin_lock_irqsave(&phb->lock, flags);
200 
201 	rc = opal_pci_get_phb_diag_data(phb->opal_id, phb->diag.blob, PNV_PCI_DIAG_BUF_SIZE);
202 	has_diag = (rc == OPAL_SUCCESS);
203 
204 	rc = opal_pci_eeh_freeze_clear(phb->opal_id, pe_no,
205 				       OPAL_EEH_ACTION_CLEAR_FREEZE_ALL);
206 	if (rc) {
207 		pr_warning("PCI %d: Failed to clear EEH freeze state"
208 			   " for PE#%d, err %ld\n",
209 			   phb->hose->global_number, pe_no, rc);
210 
211 		/* For now, let's only display the diag buffer when we fail to clear
212 		 * the EEH status. We'll do more sensible things later when we have
213 		 * proper EEH support. We need to make sure we don't pollute ourselves
214 		 * with the normal errors generated when probing empty slots
215 		 */
216 		if (has_diag)
217 			pnv_pci_dump_phb_diag_data(phb);
218 		else
219 			pr_warning("PCI %d: No diag data available\n",
220 				   phb->hose->global_number);
221 	}
222 
223 	spin_unlock_irqrestore(&phb->lock, flags);
224 }
225 
226 static void pnv_pci_config_check_eeh(struct pnv_phb *phb, struct pci_bus *bus,
227 				     u32 bdfn)
228 {
229 	s64	rc;
230 	u8	fstate;
231 	u16	pcierr;
232 	u32	pe_no;
233 
234 	/* Get PE# if we support IODA */
235 	pe_no = phb->bdfn_to_pe ? phb->bdfn_to_pe(phb, bus, bdfn & 0xff) : 0;
236 
237 	/* Read freeze status */
238 	rc = opal_pci_eeh_freeze_status(phb->opal_id, pe_no, &fstate, &pcierr,
239 					NULL);
240 	if (rc) {
241 		pr_warning("PCI %d: Failed to read EEH status for PE#%d,"
242 			   " err %lld\n", phb->hose->global_number, pe_no, rc);
243 		return;
244 	}
245 	cfg_dbg(" -> EEH check, bdfn=%04x PE%d fstate=%x\n",
246 		bdfn, pe_no, fstate);
247 	if (fstate != 0)
248 		pnv_pci_handle_eeh_config(phb, pe_no);
249 }
250 
251 static int pnv_pci_read_config(struct pci_bus *bus,
252 			       unsigned int devfn,
253 			       int where, int size, u32 *val)
254 {
255 	struct pci_controller *hose = pci_bus_to_host(bus);
256 	struct pnv_phb *phb = hose->private_data;
257 	u32 bdfn = (((uint64_t)bus->number) << 8) | devfn;
258 	s64 rc;
259 
260 	if (hose == NULL)
261 		return PCIBIOS_DEVICE_NOT_FOUND;
262 
263 	switch (size) {
264 	case 1: {
265 		u8 v8;
266 		rc = opal_pci_config_read_byte(phb->opal_id, bdfn, where, &v8);
267 		*val = (rc == OPAL_SUCCESS) ? v8 : 0xff;
268 		break;
269 	}
270 	case 2: {
271 		u16 v16;
272 		rc = opal_pci_config_read_half_word(phb->opal_id, bdfn, where,
273 						   &v16);
274 		*val = (rc == OPAL_SUCCESS) ? v16 : 0xffff;
275 		break;
276 	}
277 	case 4: {
278 		u32 v32;
279 		rc = opal_pci_config_read_word(phb->opal_id, bdfn, where, &v32);
280 		*val = (rc == OPAL_SUCCESS) ? v32 : 0xffffffff;
281 		break;
282 	}
283 	default:
284 		return PCIBIOS_FUNC_NOT_SUPPORTED;
285 	}
286 	cfg_dbg("pnv_pci_read_config bus: %x devfn: %x +%x/%x -> %08x\n",
287 		bus->number, devfn, where, size, *val);
288 
289 	/* Check if the PHB got frozen due to an error (no response) */
290 	pnv_pci_config_check_eeh(phb, bus, bdfn);
291 
292 	return PCIBIOS_SUCCESSFUL;
293 }
294 
295 static int pnv_pci_write_config(struct pci_bus *bus,
296 				unsigned int devfn,
297 				int where, int size, u32 val)
298 {
299 	struct pci_controller *hose = pci_bus_to_host(bus);
300 	struct pnv_phb *phb = hose->private_data;
301 	u32 bdfn = (((uint64_t)bus->number) << 8) | devfn;
302 
303 	if (hose == NULL)
304 		return PCIBIOS_DEVICE_NOT_FOUND;
305 
306 	cfg_dbg("pnv_pci_write_config bus: %x devfn: %x +%x/%x -> %08x\n",
307 		bus->number, devfn, where, size, val);
308 	switch (size) {
309 	case 1:
310 		opal_pci_config_write_byte(phb->opal_id, bdfn, where, val);
311 		break;
312 	case 2:
313 		opal_pci_config_write_half_word(phb->opal_id, bdfn, where, val);
314 		break;
315 	case 4:
316 		opal_pci_config_write_word(phb->opal_id, bdfn, where, val);
317 		break;
318 	default:
319 		return PCIBIOS_FUNC_NOT_SUPPORTED;
320 	}
321 	/* Check if the PHB got frozen due to an error (no response) */
322 	pnv_pci_config_check_eeh(phb, bus, bdfn);
323 
324 	return PCIBIOS_SUCCESSFUL;
325 }
326 
327 struct pci_ops pnv_pci_ops = {
328 	.read = pnv_pci_read_config,
329 	.write = pnv_pci_write_config,
330 };
331 
332 static int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
333 			 unsigned long uaddr, enum dma_data_direction direction,
334 			 struct dma_attrs *attrs)
335 {
336 	u64 proto_tce;
337 	u64 *tcep, *tces;
338 	u64 rpn;
339 
340 	proto_tce = TCE_PCI_READ; // Read allowed
341 
342 	if (direction != DMA_TO_DEVICE)
343 		proto_tce |= TCE_PCI_WRITE;
344 
345 	tces = tcep = ((u64 *)tbl->it_base) + index - tbl->it_offset;
346 	rpn = __pa(uaddr) >> TCE_SHIFT;
347 
348 	while (npages--)
349 		*(tcep++) = proto_tce | (rpn++ << TCE_RPN_SHIFT);
350 
351 	/* Some implementations won't cache invalid TCEs and thus may not
352 	 * need that flush. We'll probably turn it_type into a bit mask
353 	 * of flags if that becomes the case
354 	 */
355 	if (tbl->it_type & TCE_PCI_SWINV_CREATE)
356 		pnv_pci_ioda_tce_invalidate(tbl, tces, tcep - 1);
357 
358 	return 0;
359 }
360 
361 static void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
362 {
363 	u64 *tcep, *tces;
364 
365 	tces = tcep = ((u64 *)tbl->it_base) + index - tbl->it_offset;
366 
367 	while (npages--)
368 		*(tcep++) = 0;
369 
370 	if (tbl->it_type & TCE_PCI_SWINV_CREATE)
371 		pnv_pci_ioda_tce_invalidate(tbl, tces, tcep - 1);
372 }
373 
374 static unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
375 {
376 	return ((u64 *)tbl->it_base)[index - tbl->it_offset];
377 }
378 
379 void pnv_pci_setup_iommu_table(struct iommu_table *tbl,
380 			       void *tce_mem, u64 tce_size,
381 			       u64 dma_offset)
382 {
383 	tbl->it_blocksize = 16;
384 	tbl->it_base = (unsigned long)tce_mem;
385 	tbl->it_offset = dma_offset >> IOMMU_PAGE_SHIFT;
386 	tbl->it_index = 0;
387 	tbl->it_size = tce_size >> 3;
388 	tbl->it_busno = 0;
389 	tbl->it_type = TCE_PCI;
390 }
391 
392 static struct iommu_table *pnv_pci_setup_bml_iommu(struct pci_controller *hose)
393 {
394 	struct iommu_table *tbl;
395 	const __be64 *basep, *swinvp;
396 	const __be32 *sizep;
397 
398 	basep = of_get_property(hose->dn, "linux,tce-base", NULL);
399 	sizep = of_get_property(hose->dn, "linux,tce-size", NULL);
400 	if (basep == NULL || sizep == NULL) {
401 		pr_err("PCI: %s has missing tce entries !\n",
402 		       hose->dn->full_name);
403 		return NULL;
404 	}
405 	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL, hose->node);
406 	if (WARN_ON(!tbl))
407 		return NULL;
408 	pnv_pci_setup_iommu_table(tbl, __va(be64_to_cpup(basep)),
409 				  be32_to_cpup(sizep), 0);
410 	iommu_init_table(tbl, hose->node);
411 
412 	/* Deal with SW invalidated TCEs when needed (BML way) */
413 	swinvp = of_get_property(hose->dn, "linux,tce-sw-invalidate-info",
414 				 NULL);
415 	if (swinvp) {
416 		tbl->it_busno = swinvp[1];
417 		tbl->it_index = (unsigned long)ioremap(swinvp[0], 8);
418 		tbl->it_type = TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE;
419 	}
420 	return tbl;
421 }
422 
423 static void pnv_pci_dma_fallback_setup(struct pci_controller *hose,
424 				       struct pci_dev *pdev)
425 {
426 	struct device_node *np = pci_bus_to_OF_node(hose->bus);
427 	struct pci_dn *pdn;
428 
429 	if (np == NULL)
430 		return;
431 	pdn = PCI_DN(np);
432 	if (!pdn->iommu_table)
433 		pdn->iommu_table = pnv_pci_setup_bml_iommu(hose);
434 	if (!pdn->iommu_table)
435 		return;
436 	set_iommu_table_base(&pdev->dev, pdn->iommu_table);
437 }
438 
439 static void pnv_pci_dma_dev_setup(struct pci_dev *pdev)
440 {
441 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
442 	struct pnv_phb *phb = hose->private_data;
443 
444 	/* If we have no phb structure, try to setup a fallback based on
445 	 * the device-tree (RTAS PCI for example)
446 	 */
447 	if (phb && phb->dma_dev_setup)
448 		phb->dma_dev_setup(phb, pdev);
449 	else
450 		pnv_pci_dma_fallback_setup(hose, pdev);
451 }
452 
453 /* Fixup wrong class code in p7ioc and p8 root complex */
454 static void pnv_p7ioc_rc_quirk(struct pci_dev *dev)
455 {
456 	dev->class = PCI_CLASS_BRIDGE_PCI << 8;
457 }
458 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_IBM, 0x3b9, pnv_p7ioc_rc_quirk);
459 
460 static int pnv_pci_probe_mode(struct pci_bus *bus)
461 {
462 	struct pci_controller *hose = pci_bus_to_host(bus);
463 	const __be64 *tstamp;
464 	u64 now, target;
465 
466 
467 	/* We hijack this as a way to ensure we have waited long
468 	 * enough since the reset was lifted on the PCI bus
469 	 */
470 	if (bus != hose->bus)
471 		return PCI_PROBE_NORMAL;
472 	tstamp = of_get_property(hose->dn, "reset-clear-timestamp", NULL);
473 	if (!tstamp || !*tstamp)
474 		return PCI_PROBE_NORMAL;
475 
476 	now = mftb() / tb_ticks_per_usec;
477 	target = (be64_to_cpup(tstamp) / tb_ticks_per_usec)
478 		+ PCI_RESET_DELAY_US;
479 
480 	pr_devel("pci %04d: Reset target: 0x%llx now: 0x%llx\n",
481 		 hose->global_number, target, now);
482 
483 	if (now < target)
484 		msleep((target - now + 999) / 1000);
485 
486 	return PCI_PROBE_NORMAL;
487 }
488 
489 void __init pnv_pci_init(void)
490 {
491 	struct device_node *np;
492 
493 	pci_add_flags(PCI_CAN_SKIP_ISA_ALIGN);
494 
495 	/* OPAL absent, try POPAL first then RTAS detection of PHBs */
496 	if (!firmware_has_feature(FW_FEATURE_OPAL)) {
497 #ifdef CONFIG_PPC_POWERNV_RTAS
498 		init_pci_config_tokens();
499 		find_and_init_phbs();
500 #endif /* CONFIG_PPC_POWERNV_RTAS */
501 	}
502 	/* OPAL is here, do our normal stuff */
503 	else {
504 		int found_ioda = 0;
505 
506 		/* Look for IODA IO-Hubs. We don't support mixing IODA
507 		 * and p5ioc2 due to the need to change some global
508 		 * probing flags
509 		 */
510 		for_each_compatible_node(np, NULL, "ibm,ioda-hub") {
511 			pnv_pci_init_ioda_hub(np);
512 			found_ioda = 1;
513 		}
514 
515 		/* Look for p5ioc2 IO-Hubs */
516 		if (!found_ioda)
517 			for_each_compatible_node(np, NULL, "ibm,p5ioc2")
518 				pnv_pci_init_p5ioc2_hub(np);
519 
520 		/* Look for ioda2 built-in PHB3's */
521 		for_each_compatible_node(np, NULL, "ibm,ioda2-phb")
522 			pnv_pci_init_ioda2_phb(np);
523 	}
524 
525 	/* Setup the linkage between OF nodes and PHBs */
526 	pci_devs_phb_init();
527 
528 	/* Configure IOMMU DMA hooks */
529 	ppc_md.pci_dma_dev_setup = pnv_pci_dma_dev_setup;
530 	ppc_md.tce_build = pnv_tce_build;
531 	ppc_md.tce_free = pnv_tce_free;
532 	ppc_md.tce_get = pnv_tce_get;
533 	ppc_md.pci_probe_mode = pnv_pci_probe_mode;
534 	set_pci_dma_ops(&dma_iommu_ops);
535 
536 	/* Configure MSIs */
537 #ifdef CONFIG_PCI_MSI
538 	ppc_md.msi_check_device = pnv_msi_check_device;
539 	ppc_md.setup_msi_irqs = pnv_setup_msi_irqs;
540 	ppc_md.teardown_msi_irqs = pnv_teardown_msi_irqs;
541 #endif
542 }
543