xref: /linux/arch/powerpc/platforms/pseries/iommu.c (revision bed59275810a55500e885cbdc5c2a0507f13c00e)
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 = (struct device_node *)phb->arch_data;
255 
256 	basep = get_property(node, "linux,tce-base", NULL);
257 	sizep = 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 {
301 	unsigned long offset, size;
302 
303 	tbl->it_busno  = PCI_DN(dn)->bussubno;
304 	of_parse_dma_window(dn, dma_window, &tbl->it_index, &offset, &size);
305 
306 	tbl->it_base   = 0;
307 	tbl->it_blocksize  = 16;
308 	tbl->it_type = TCE_PCI;
309 	tbl->it_offset = offset >> IOMMU_PAGE_SHIFT;
310 	tbl->it_size = size >> IOMMU_PAGE_SHIFT;
311 }
312 
313 static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
314 {
315 	struct device_node *dn;
316 	struct iommu_table *tbl;
317 	struct device_node *isa_dn, *isa_dn_orig;
318 	struct device_node *tmp;
319 	struct pci_dn *pci;
320 	int children;
321 
322 	dn = pci_bus_to_OF_node(bus);
323 
324 	DBG("pci_dma_bus_setup_pSeries: setting up bus %s\n", dn->full_name);
325 
326 	if (bus->self) {
327 		/* This is not a root bus, any setup will be done for the
328 		 * device-side of the bridge in iommu_dev_setup_pSeries().
329 		 */
330 		return;
331 	}
332 	pci = PCI_DN(dn);
333 
334 	/* Check if the ISA bus on the system is under
335 	 * this PHB.
336 	 */
337 	isa_dn = isa_dn_orig = of_find_node_by_type(NULL, "isa");
338 
339 	while (isa_dn && isa_dn != dn)
340 		isa_dn = isa_dn->parent;
341 
342 	if (isa_dn_orig)
343 		of_node_put(isa_dn_orig);
344 
345 	/* Count number of direct PCI children of the PHB. */
346 	for (children = 0, tmp = dn->child; tmp; tmp = tmp->sibling)
347 		children++;
348 
349 	DBG("Children: %d\n", children);
350 
351 	/* Calculate amount of DMA window per slot. Each window must be
352 	 * a power of two (due to pci_alloc_consistent requirements).
353 	 *
354 	 * Keep 256MB aside for PHBs with ISA.
355 	 */
356 
357 	if (!isa_dn) {
358 		/* No ISA/IDE - just set window size and return */
359 		pci->phb->dma_window_size = 0x80000000ul; /* To be divided */
360 
361 		while (pci->phb->dma_window_size * children > 0x80000000ul)
362 			pci->phb->dma_window_size >>= 1;
363 		DBG("No ISA/IDE, window size is 0x%lx\n",
364 			pci->phb->dma_window_size);
365 		pci->phb->dma_window_base_cur = 0;
366 
367 		return;
368 	}
369 
370 	/* If we have ISA, then we probably have an IDE
371 	 * controller too. Allocate a 128MB table but
372 	 * skip the first 128MB to avoid stepping on ISA
373 	 * space.
374 	 */
375 	pci->phb->dma_window_size = 0x8000000ul;
376 	pci->phb->dma_window_base_cur = 0x8000000ul;
377 
378 	tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
379 			   pci->phb->node);
380 
381 	iommu_table_setparms(pci->phb, dn, tbl);
382 	pci->iommu_table = iommu_init_table(tbl, pci->phb->node);
383 
384 	/* Divide the rest (1.75GB) among the children */
385 	pci->phb->dma_window_size = 0x80000000ul;
386 	while (pci->phb->dma_window_size * children > 0x70000000ul)
387 		pci->phb->dma_window_size >>= 1;
388 
389 	DBG("ISA/IDE, window size is 0x%lx\n", pci->phb->dma_window_size);
390 
391 }
392 
393 
394 static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
395 {
396 	struct iommu_table *tbl;
397 	struct device_node *dn, *pdn;
398 	struct pci_dn *ppci;
399 	const void *dma_window = NULL;
400 
401 	dn = pci_bus_to_OF_node(bus);
402 
403 	DBG("pci_dma_bus_setup_pSeriesLP: setting up bus %s\n", dn->full_name);
404 
405 	/* Find nearest ibm,dma-window, walking up the device tree */
406 	for (pdn = dn; pdn != NULL; pdn = pdn->parent) {
407 		dma_window = get_property(pdn, "ibm,dma-window", NULL);
408 		if (dma_window != NULL)
409 			break;
410 	}
411 
412 	if (dma_window == NULL) {
413 		DBG("  no ibm,dma-window property !\n");
414 		return;
415 	}
416 
417 	ppci = PCI_DN(pdn);
418 
419 	DBG("  parent is %s, iommu_table: 0x%p\n",
420 	    pdn->full_name, ppci->iommu_table);
421 
422 	if (!ppci->iommu_table) {
423 		/* Bussubno hasn't been copied yet.
424 		 * Do it now because iommu_table_setparms_lpar needs it.
425 		 */
426 
427 		ppci->bussubno = bus->number;
428 
429 		tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
430 				   ppci->phb->node);
431 
432 		iommu_table_setparms_lpar(ppci->phb, pdn, tbl, dma_window);
433 
434 		ppci->iommu_table = iommu_init_table(tbl, ppci->phb->node);
435 		DBG("  created table: %p\n", ppci->iommu_table);
436 	}
437 
438 	if (pdn != dn)
439 		PCI_DN(dn)->iommu_table = ppci->iommu_table;
440 }
441 
442 
443 static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
444 {
445 	struct device_node *dn;
446 	struct iommu_table *tbl;
447 
448 	DBG("pci_dma_dev_setup_pSeries: %s\n", pci_name(dev));
449 
450 	dn = dev->dev.archdata.of_node;
451 
452 	/* If we're the direct child of a root bus, then we need to allocate
453 	 * an iommu table ourselves. The bus setup code should have setup
454 	 * the window sizes already.
455 	 */
456 	if (!dev->bus->self) {
457 		struct pci_controller *phb = PCI_DN(dn)->phb;
458 
459 		DBG(" --> first child, no bridge. Allocating iommu table.\n");
460 		tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
461 				   phb->node);
462 		iommu_table_setparms(phb, dn, tbl);
463 		PCI_DN(dn)->iommu_table = iommu_init_table(tbl, phb->node);
464 		dev->dev.archdata.dma_data = PCI_DN(dn)->iommu_table;
465 		return;
466 	}
467 
468 	/* If this device is further down the bus tree, search upwards until
469 	 * an already allocated iommu table is found and use that.
470 	 */
471 
472 	while (dn && PCI_DN(dn) && PCI_DN(dn)->iommu_table == NULL)
473 		dn = dn->parent;
474 
475 	if (dn && PCI_DN(dn))
476 		dev->dev.archdata.dma_data = PCI_DN(dn)->iommu_table;
477 	else
478 		printk(KERN_WARNING "iommu: Device %s has no iommu table\n",
479 		       pci_name(dev));
480 }
481 
482 static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
483 {
484 	struct device_node *pdn, *dn;
485 	struct iommu_table *tbl;
486 	const void *dma_window = NULL;
487 	struct pci_dn *pci;
488 
489 	DBG("pci_dma_dev_setup_pSeriesLP: %s\n", pci_name(dev));
490 
491 	/* dev setup for LPAR is a little tricky, since the device tree might
492 	 * contain the dma-window properties per-device and not neccesarily
493 	 * for the bus. So we need to search upwards in the tree until we
494 	 * either hit a dma-window property, OR find a parent with a table
495 	 * already allocated.
496 	 */
497 	dn = pci_device_to_OF_node(dev);
498 	DBG("  node is %s\n", dn->full_name);
499 
500 	for (pdn = dn; pdn && PCI_DN(pdn) && !PCI_DN(pdn)->iommu_table;
501 	     pdn = pdn->parent) {
502 		dma_window = get_property(pdn, "ibm,dma-window", NULL);
503 		if (dma_window)
504 			break;
505 	}
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 	DBG("  found DMA window, table: %p\n", pci->iommu_table);
518 
519 	pci = PCI_DN(pdn);
520 	if (!pci->iommu_table) {
521 		/* iommu_table_setparms_lpar needs bussubno. */
522 		pci->bussubno = pci->phb->bus->number;
523 
524 		tbl = kmalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
525 				   pci->phb->node);
526 
527 		iommu_table_setparms_lpar(pci->phb, pdn, tbl, dma_window);
528 
529 		pci->iommu_table = iommu_init_table(tbl, pci->phb->node);
530 		DBG("  created table: %p\n", pci->iommu_table);
531 	}
532 
533 	dev->dev.archdata.dma_data = pci->iommu_table;
534 }
535 #else  /* CONFIG_PCI */
536 #define pci_dma_bus_setup_pSeries	NULL
537 #define pci_dma_dev_setup_pSeries	NULL
538 #define pci_dma_bus_setup_pSeriesLP	NULL
539 #define pci_dma_dev_setup_pSeriesLP	NULL
540 #endif /* !CONFIG_PCI */
541 
542 static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
543 {
544 	int err = NOTIFY_OK;
545 	struct device_node *np = node;
546 	struct pci_dn *pci = PCI_DN(np);
547 
548 	switch (action) {
549 	case PSERIES_RECONFIG_REMOVE:
550 		if (pci && pci->iommu_table &&
551 		    get_property(np, "ibm,dma-window", NULL))
552 			iommu_free_table(np);
553 		break;
554 	default:
555 		err = NOTIFY_DONE;
556 		break;
557 	}
558 	return err;
559 }
560 
561 static struct notifier_block iommu_reconfig_nb = {
562 	.notifier_call = iommu_reconfig_notifier,
563 };
564 
565 /* These are called very early. */
566 void iommu_init_early_pSeries(void)
567 {
568 	if (of_chosen && get_property(of_chosen, "linux,iommu-off", NULL)) {
569 		/* Direct I/O, IOMMU off */
570 		ppc_md.pci_dma_dev_setup = NULL;
571 		ppc_md.pci_dma_bus_setup = NULL;
572 		set_pci_dma_ops(&dma_direct_ops);
573 		return;
574 	}
575 
576 	if (firmware_has_feature(FW_FEATURE_LPAR)) {
577 		if (firmware_has_feature(FW_FEATURE_MULTITCE)) {
578 			ppc_md.tce_build = tce_buildmulti_pSeriesLP;
579 			ppc_md.tce_free	 = tce_freemulti_pSeriesLP;
580 		} else {
581 			ppc_md.tce_build = tce_build_pSeriesLP;
582 			ppc_md.tce_free	 = tce_free_pSeriesLP;
583 		}
584 		ppc_md.tce_get   = tce_get_pSeriesLP;
585 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pSeriesLP;
586 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pSeriesLP;
587 	} else {
588 		ppc_md.tce_build = tce_build_pSeries;
589 		ppc_md.tce_free  = tce_free_pSeries;
590 		ppc_md.tce_get   = tce_get_pseries;
591 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pSeries;
592 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pSeries;
593 	}
594 
595 
596 	pSeries_reconfig_notifier_register(&iommu_reconfig_nb);
597 
598 	set_pci_dma_ops(&dma_iommu_ops);
599 }
600 
601