1 /*
2  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
3  *
4  * Rewrite, cleanup:
5  *
6  * Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
7  * Copyright (C) 2006 Olof Johansson <olof@lixom.net>
8  *
9  * Dynamic DMA mapping support, pSeries-specific parts, both SMP and LPAR.
10  *
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
25  */
26 
27 #include <linux/init.h>
28 #include <linux/types.h>
29 #include <linux/slab.h>
30 #include <linux/mm.h>
31 #include <linux/spinlock.h>
32 #include <linux/string.h>
33 #include <linux/pci.h>
34 #include <linux/dma-mapping.h>
35 #include <asm/io.h>
36 #include <asm/prom.h>
37 #include <asm/rtas.h>
38 #include <asm/iommu.h>
39 #include <asm/pci-bridge.h>
40 #include <asm/machdep.h>
41 #include <asm/abs_addr.h>
42 #include <asm/pSeries_reconfig.h>
43 #include <asm/firmware.h>
44 #include <asm/tce.h>
45 #include <asm/ppc-pci.h>
46 #include <asm/udbg.h>
47 
48 #include "plpar_wrappers.h"
49 
50 #define DBG(fmt...)
51 
52 static void tce_build_pSeries(struct iommu_table *tbl, long index,
53 			      long npages, unsigned long uaddr,
54 			      enum dma_data_direction direction)
55 {
56 	u64 proto_tce;
57 	u64 *tcep;
58 	u64 rpn;
59 
60 	proto_tce = TCE_PCI_READ; // Read allowed
61 
62 	if (direction != DMA_TO_DEVICE)
63 		proto_tce |= TCE_PCI_WRITE;
64 
65 	tcep = ((u64 *)tbl->it_base) + index;
66 
67 	while (npages--) {
68 		/* can't move this out since we might cross LMB boundary */
69 		rpn = (virt_to_abs(uaddr)) >> TCE_SHIFT;
70 		*tcep = proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
71 
72 		uaddr += TCE_PAGE_SIZE;
73 		tcep++;
74 	}
75 }
76 
77 
78 static void tce_free_pSeries(struct iommu_table *tbl, long index, long npages)
79 {
80 	u64 *tcep;
81 
82 	tcep = ((u64 *)tbl->it_base) + index;
83 
84 	while (npages--)
85 		*(tcep++) = 0;
86 }
87 
88 static unsigned long tce_get_pseries(struct iommu_table *tbl, long index)
89 {
90 	u64 *tcep;
91 
92 	tcep = ((u64 *)tbl->it_base) + index;
93 
94 	return *tcep;
95 }
96 
97 static void tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum,
98 				long npages, unsigned long uaddr,
99 				enum dma_data_direction direction)
100 {
101 	u64 rc;
102 	u64 proto_tce, tce;
103 	u64 rpn;
104 
105 	rpn = (virt_to_abs(uaddr)) >> TCE_SHIFT;
106 	proto_tce = TCE_PCI_READ;
107 	if (direction != DMA_TO_DEVICE)
108 		proto_tce |= TCE_PCI_WRITE;
109 
110 	while (npages--) {
111 		tce = proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
112 		rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, tce);
113 
114 		if (rc && printk_ratelimit()) {
115 			printk("tce_build_pSeriesLP: plpar_tce_put failed. rc=%ld\n", rc);
116 			printk("\tindex   = 0x%lx\n", (u64)tbl->it_index);
117 			printk("\ttcenum  = 0x%lx\n", (u64)tcenum);
118 			printk("\ttce val = 0x%lx\n", tce );
119 			show_stack(current, (unsigned long *)__get_SP());
120 		}
121 
122 		tcenum++;
123 		rpn++;
124 	}
125 }
126 
127 static DEFINE_PER_CPU(u64 *, tce_page) = NULL;
128 
129 static void tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
130 				     long npages, unsigned long uaddr,
131 				     enum dma_data_direction direction)
132 {
133 	u64 rc;
134 	u64 proto_tce;
135 	u64 *tcep;
136 	u64 rpn;
137 	long l, limit;
138 
139 	if (npages == 1)
140 		return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
141 					   direction);
142 
143 	tcep = __get_cpu_var(tce_page);
144 
145 	/* This is safe to do since interrupts are off when we're called
146 	 * from iommu_alloc{,_sg}()
147 	 */
148 	if (!tcep) {
149 		tcep = (u64 *)__get_free_page(GFP_ATOMIC);
150 		/* If allocation fails, fall back to the loop implementation */
151 		if (!tcep)
152 			return tce_build_pSeriesLP(tbl, tcenum, npages,
153 						   uaddr, direction);
154 		__get_cpu_var(tce_page) = tcep;
155 	}
156 
157 	rpn = (virt_to_abs(uaddr)) >> TCE_SHIFT;
158 	proto_tce = TCE_PCI_READ;
159 	if (direction != DMA_TO_DEVICE)
160 		proto_tce |= TCE_PCI_WRITE;
161 
162 	/* We can map max one pageful of TCEs at a time */
163 	do {
164 		/*
165 		 * Set up the page with TCE data, looping through and setting
166 		 * the values.
167 		 */
168 		limit = min_t(long, npages, 4096/TCE_ENTRY_SIZE);
169 
170 		for (l = 0; l < limit; l++) {
171 			tcep[l] = proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
172 			rpn++;
173 		}
174 
175 		rc = plpar_tce_put_indirect((u64)tbl->it_index,
176 					    (u64)tcenum << 12,
177 					    (u64)virt_to_abs(tcep),
178 					    limit);
179 
180 		npages -= limit;
181 		tcenum += limit;
182 	} while (npages > 0 && !rc);
183 
184 	if (rc && printk_ratelimit()) {
185 		printk("tce_buildmulti_pSeriesLP: plpar_tce_put failed. rc=%ld\n", rc);
186 		printk("\tindex   = 0x%lx\n", (u64)tbl->it_index);
187 		printk("\tnpages  = 0x%lx\n", (u64)npages);
188 		printk("\ttce[0] val = 0x%lx\n", tcep[0]);
189 		show_stack(current, (unsigned long *)__get_SP());
190 	}
191 }
192 
193 static void tce_free_pSeriesLP(struct iommu_table *tbl, long tcenum, long npages)
194 {
195 	u64 rc;
196 
197 	while (npages--) {
198 		rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, 0);
199 
200 		if (rc && printk_ratelimit()) {
201 			printk("tce_free_pSeriesLP: plpar_tce_put failed. rc=%ld\n", rc);
202 			printk("\tindex   = 0x%lx\n", (u64)tbl->it_index);
203 			printk("\ttcenum  = 0x%lx\n", (u64)tcenum);
204 			show_stack(current, (unsigned long *)__get_SP());
205 		}
206 
207 		tcenum++;
208 	}
209 }
210 
211 
212 static void tce_freemulti_pSeriesLP(struct iommu_table *tbl, long tcenum, long npages)
213 {
214 	u64 rc;
215 
216 	rc = plpar_tce_stuff((u64)tbl->it_index, (u64)tcenum << 12, 0, npages);
217 
218 	if (rc && printk_ratelimit()) {
219 		printk("tce_freemulti_pSeriesLP: plpar_tce_stuff failed\n");
220 		printk("\trc      = %ld\n", rc);
221 		printk("\tindex   = 0x%lx\n", (u64)tbl->it_index);
222 		printk("\tnpages  = 0x%lx\n", (u64)npages);
223 		show_stack(current, (unsigned long *)__get_SP());
224 	}
225 }
226 
227 static unsigned long tce_get_pSeriesLP(struct iommu_table *tbl, long tcenum)
228 {
229 	u64 rc;
230 	unsigned long tce_ret;
231 
232 	rc = plpar_tce_get((u64)tbl->it_index, (u64)tcenum << 12, &tce_ret);
233 
234 	if (rc && printk_ratelimit()) {
235 		printk("tce_get_pSeriesLP: plpar_tce_get failed. rc=%ld\n",
236 			rc);
237 		printk("\tindex   = 0x%lx\n", (u64)tbl->it_index);
238 		printk("\ttcenum  = 0x%lx\n", (u64)tcenum);
239 		show_stack(current, (unsigned long *)__get_SP());
240 	}
241 
242 	return tce_ret;
243 }
244 
245 #ifdef CONFIG_PCI
246 static void iommu_table_setparms(struct pci_controller *phb,
247 				 struct device_node *dn,
248 				 struct iommu_table *tbl)
249 {
250 	struct device_node *node;
251 	const unsigned long *basep;
252 	const u32 *sizep;
253 
254 	node = phb->dn;
255 
256 	basep = of_get_property(node, "linux,tce-base", NULL);
257 	sizep = of_get_property(node, "linux,tce-size", NULL);
258 	if (basep == NULL || sizep == NULL) {
259 		printk(KERN_ERR "PCI_DMA: iommu_table_setparms: %s has "
260 				"missing tce entries !\n", dn->full_name);
261 		return;
262 	}
263 
264 	tbl->it_base = (unsigned long)__va(*basep);
265 
266 #ifndef CONFIG_CRASH_DUMP
267 	memset((void *)tbl->it_base, 0, *sizep);
268 #endif
269 
270 	tbl->it_busno = phb->bus->number;
271 
272 	/* Units of tce entries */
273 	tbl->it_offset = phb->dma_window_base_cur >> IOMMU_PAGE_SHIFT;
274 
275 	/* Test if we are going over 2GB of DMA space */
276 	if (phb->dma_window_base_cur + phb->dma_window_size > 0x80000000ul) {
277 		udbg_printf("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
278 		panic("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
279 	}
280 
281 	phb->dma_window_base_cur += phb->dma_window_size;
282 
283 	/* Set the tce table size - measured in entries */
284 	tbl->it_size = phb->dma_window_size >> IOMMU_PAGE_SHIFT;
285 
286 	tbl->it_index = 0;
287 	tbl->it_blocksize = 16;
288 	tbl->it_type = TCE_PCI;
289 }
290 
291 /*
292  * iommu_table_setparms_lpar
293  *
294  * Function: On pSeries LPAR systems, return TCE table info, given a pci bus.
295  */
296 static void iommu_table_setparms_lpar(struct pci_controller *phb,
297 				      struct device_node *dn,
298 				      struct iommu_table *tbl,
299 				      const void *dma_window,
300 				      int bussubno)
301 {
302 	unsigned long offset, size;
303 
304 	tbl->it_busno  = bussubno;
305 	of_parse_dma_window(dn, dma_window, &tbl->it_index, &offset, &size);
306 
307 	tbl->it_base   = 0;
308 	tbl->it_blocksize  = 16;
309 	tbl->it_type = TCE_PCI;
310 	tbl->it_offset = offset >> IOMMU_PAGE_SHIFT;
311 	tbl->it_size = size >> IOMMU_PAGE_SHIFT;
312 }
313 
314 static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
315 {
316 	struct device_node *dn;
317 	struct iommu_table *tbl;
318 	struct device_node *isa_dn, *isa_dn_orig;
319 	struct device_node *tmp;
320 	struct pci_dn *pci;
321 	int children;
322 
323 	dn = pci_bus_to_OF_node(bus);
324 
325 	DBG("pci_dma_bus_setup_pSeries: setting up bus %s\n", dn->full_name);
326 
327 	if (bus->self) {
328 		/* This is not a root bus, any setup will be done for the
329 		 * device-side of the bridge in iommu_dev_setup_pSeries().
330 		 */
331 		return;
332 	}
333 	pci = PCI_DN(dn);
334 
335 	/* Check if the ISA bus on the system is under
336 	 * this PHB.
337 	 */
338 	isa_dn = isa_dn_orig = of_find_node_by_type(NULL, "isa");
339 
340 	while (isa_dn && isa_dn != dn)
341 		isa_dn = isa_dn->parent;
342 
343 	if (isa_dn_orig)
344 		of_node_put(isa_dn_orig);
345 
346 	/* Count number of direct PCI children of the PHB. */
347 	for (children = 0, tmp = dn->child; tmp; tmp = tmp->sibling)
348 		children++;
349 
350 	DBG("Children: %d\n", children);
351 
352 	/* Calculate amount of DMA window per slot. Each window must be
353 	 * a power of two (due to pci_alloc_consistent requirements).
354 	 *
355 	 * Keep 256MB aside for PHBs with ISA.
356 	 */
357 
358 	if (!isa_dn) {
359 		/* No ISA/IDE - just set window size and return */
360 		pci->phb->dma_window_size = 0x80000000ul; /* To be divided */
361 
362 		while (pci->phb->dma_window_size * children > 0x80000000ul)
363 			pci->phb->dma_window_size >>= 1;
364 		DBG("No ISA/IDE, window size is 0x%lx\n",
365 			pci->phb->dma_window_size);
366 		pci->phb->dma_window_base_cur = 0;
367 
368 		return;
369 	}
370 
371 	/* If we have ISA, then we probably have an IDE
372 	 * controller too. Allocate a 128MB table but
373 	 * skip the first 128MB to avoid stepping on ISA
374 	 * space.
375 	 */
376 	pci->phb->dma_window_size = 0x8000000ul;
377 	pci->phb->dma_window_base_cur = 0x8000000ul;
378 
379 	tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
380 			   pci->phb->node);
381 
382 	iommu_table_setparms(pci->phb, dn, tbl);
383 	pci->iommu_table = iommu_init_table(tbl, pci->phb->node);
384 
385 	/* Divide the rest (1.75GB) among the children */
386 	pci->phb->dma_window_size = 0x80000000ul;
387 	while (pci->phb->dma_window_size * children > 0x70000000ul)
388 		pci->phb->dma_window_size >>= 1;
389 
390 	DBG("ISA/IDE, window size is 0x%lx\n", pci->phb->dma_window_size);
391 
392 }
393 
394 
395 static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
396 {
397 	struct iommu_table *tbl;
398 	struct device_node *dn, *pdn;
399 	struct pci_dn *ppci;
400 	const void *dma_window = NULL;
401 
402 	dn = pci_bus_to_OF_node(bus);
403 
404 	DBG("pci_dma_bus_setup_pSeriesLP: setting up bus %s\n", dn->full_name);
405 
406 	/* Find nearest ibm,dma-window, walking up the device tree */
407 	for (pdn = dn; pdn != NULL; pdn = pdn->parent) {
408 		dma_window = of_get_property(pdn, "ibm,dma-window", NULL);
409 		if (dma_window != NULL)
410 			break;
411 	}
412 
413 	if (dma_window == NULL) {
414 		DBG("  no ibm,dma-window property !\n");
415 		return;
416 	}
417 
418 	ppci = PCI_DN(pdn);
419 
420 	DBG("  parent is %s, iommu_table: 0x%p\n",
421 	    pdn->full_name, ppci->iommu_table);
422 
423 	if (!ppci->iommu_table) {
424 		tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
425 				   ppci->phb->node);
426 		iommu_table_setparms_lpar(ppci->phb, pdn, tbl, dma_window,
427 			bus->number);
428 		ppci->iommu_table = iommu_init_table(tbl, ppci->phb->node);
429 		DBG("  created table: %p\n", ppci->iommu_table);
430 	}
431 
432 	if (pdn != dn)
433 		PCI_DN(dn)->iommu_table = ppci->iommu_table;
434 }
435 
436 
437 static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
438 {
439 	struct device_node *dn;
440 	struct iommu_table *tbl;
441 
442 	DBG("pci_dma_dev_setup_pSeries: %s\n", pci_name(dev));
443 
444 	dn = dev->dev.archdata.of_node;
445 
446 	/* If we're the direct child of a root bus, then we need to allocate
447 	 * an iommu table ourselves. The bus setup code should have setup
448 	 * the window sizes already.
449 	 */
450 	if (!dev->bus->self) {
451 		struct pci_controller *phb = PCI_DN(dn)->phb;
452 
453 		DBG(" --> first child, no bridge. Allocating iommu table.\n");
454 		tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
455 				   phb->node);
456 		iommu_table_setparms(phb, dn, tbl);
457 		PCI_DN(dn)->iommu_table = iommu_init_table(tbl, phb->node);
458 		dev->dev.archdata.dma_data = PCI_DN(dn)->iommu_table;
459 		return;
460 	}
461 
462 	/* If this device is further down the bus tree, search upwards until
463 	 * an already allocated iommu table is found and use that.
464 	 */
465 
466 	while (dn && PCI_DN(dn) && PCI_DN(dn)->iommu_table == NULL)
467 		dn = dn->parent;
468 
469 	if (dn && PCI_DN(dn))
470 		dev->dev.archdata.dma_data = PCI_DN(dn)->iommu_table;
471 	else
472 		printk(KERN_WARNING "iommu: Device %s has no iommu table\n",
473 		       pci_name(dev));
474 }
475 
476 static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
477 {
478 	struct device_node *pdn, *dn;
479 	struct iommu_table *tbl;
480 	const void *dma_window = NULL;
481 	struct pci_dn *pci;
482 
483 	DBG("pci_dma_dev_setup_pSeriesLP: %s\n", pci_name(dev));
484 
485 	/* dev setup for LPAR is a little tricky, since the device tree might
486 	 * contain the dma-window properties per-device and not neccesarily
487 	 * for the bus. So we need to search upwards in the tree until we
488 	 * either hit a dma-window property, OR find a parent with a table
489 	 * already allocated.
490 	 */
491 	dn = pci_device_to_OF_node(dev);
492 	DBG("  node is %s\n", dn->full_name);
493 
494 	for (pdn = dn; pdn && PCI_DN(pdn) && !PCI_DN(pdn)->iommu_table;
495 	     pdn = pdn->parent) {
496 		dma_window = of_get_property(pdn, "ibm,dma-window", NULL);
497 		if (dma_window)
498 			break;
499 	}
500 
501 	if (!pdn || !PCI_DN(pdn)) {
502 		printk(KERN_WARNING "pci_dma_dev_setup_pSeriesLP: "
503 		       "no DMA window found for pci dev=%s dn=%s\n",
504 				 pci_name(dev), dn? dn->full_name : "<null>");
505 		return;
506 	}
507 	DBG("  parent is %s\n", pdn->full_name);
508 
509 	/* Check for parent == NULL so we don't try to setup the empty EADS
510 	 * slots on POWER4 machines.
511 	 */
512 	if (dma_window == NULL || pdn->parent == NULL) {
513 		DBG("  no dma window for device, linking to parent\n");
514 		dev->dev.archdata.dma_data = PCI_DN(pdn)->iommu_table;
515 		return;
516 	}
517 
518 	pci = PCI_DN(pdn);
519 	if (!pci->iommu_table) {
520 		tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
521 				   pci->phb->node);
522 		iommu_table_setparms_lpar(pci->phb, pdn, tbl, dma_window,
523 			pci->phb->bus->number);
524 		pci->iommu_table = iommu_init_table(tbl, pci->phb->node);
525 		DBG("  created table: %p\n", pci->iommu_table);
526 	} else {
527 		DBG("  found DMA window, table: %p\n", pci->iommu_table);
528 	}
529 
530 	dev->dev.archdata.dma_data = pci->iommu_table;
531 }
532 #else  /* CONFIG_PCI */
533 #define pci_dma_bus_setup_pSeries	NULL
534 #define pci_dma_dev_setup_pSeries	NULL
535 #define pci_dma_bus_setup_pSeriesLP	NULL
536 #define pci_dma_dev_setup_pSeriesLP	NULL
537 #endif /* !CONFIG_PCI */
538 
539 static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
540 {
541 	int err = NOTIFY_OK;
542 	struct device_node *np = node;
543 	struct pci_dn *pci = PCI_DN(np);
544 
545 	switch (action) {
546 	case PSERIES_RECONFIG_REMOVE:
547 		if (pci && pci->iommu_table &&
548 		    of_get_property(np, "ibm,dma-window", NULL))
549 			iommu_free_table(pci->iommu_table, np->full_name);
550 		break;
551 	default:
552 		err = NOTIFY_DONE;
553 		break;
554 	}
555 	return err;
556 }
557 
558 static struct notifier_block iommu_reconfig_nb = {
559 	.notifier_call = iommu_reconfig_notifier,
560 };
561 
562 /* These are called very early. */
563 void iommu_init_early_pSeries(void)
564 {
565 	if (of_chosen && of_get_property(of_chosen, "linux,iommu-off", NULL)) {
566 		/* Direct I/O, IOMMU off */
567 		ppc_md.pci_dma_dev_setup = NULL;
568 		ppc_md.pci_dma_bus_setup = NULL;
569 		set_pci_dma_ops(&dma_direct_ops);
570 		return;
571 	}
572 
573 	if (firmware_has_feature(FW_FEATURE_LPAR)) {
574 		if (firmware_has_feature(FW_FEATURE_MULTITCE)) {
575 			ppc_md.tce_build = tce_buildmulti_pSeriesLP;
576 			ppc_md.tce_free	 = tce_freemulti_pSeriesLP;
577 		} else {
578 			ppc_md.tce_build = tce_build_pSeriesLP;
579 			ppc_md.tce_free	 = tce_free_pSeriesLP;
580 		}
581 		ppc_md.tce_get   = tce_get_pSeriesLP;
582 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pSeriesLP;
583 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pSeriesLP;
584 	} else {
585 		ppc_md.tce_build = tce_build_pSeries;
586 		ppc_md.tce_free  = tce_free_pSeries;
587 		ppc_md.tce_get   = tce_get_pseries;
588 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pSeries;
589 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pSeries;
590 	}
591 
592 
593 	pSeries_reconfig_notifier_register(&iommu_reconfig_nb);
594 
595 	set_pci_dma_ops(&dma_iommu_ops);
596 }
597 
598