2 * IOMMU implementation for Cell Broadband Processor Architecture
4 * (C) Copyright IBM Corporation 2006-2008
6 * Author: Jeremy Kerr <jk@ozlabs.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include <linux/kernel.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/notifier.h>
30 #include <linux/of_platform.h>
31 #include <linux/slab.h>
32 #include <linux/memblock.h>
35 #include <asm/iommu.h>
36 #include <asm/machdep.h>
37 #include <asm/pci-bridge.h>
39 #include <asm/firmware.h>
40 #include <asm/cell-regs.h>
43 #include "interrupt.h"
45 /* Define CELL_IOMMU_REAL_UNMAP to actually unmap non-used pages
46 * instead of leaving them mapped to some dummy page. This can be
47 * enabled once the appropriate workarounds for spider bugs have
50 #define CELL_IOMMU_REAL_UNMAP
52 /* Define CELL_IOMMU_STRICT_PROTECTION to enforce protection of
53 * IO PTEs based on the transfer direction. That can be enabled
54 * once spider-net has been fixed to pass the correct direction
55 * to the DMA mapping functions
57 #define CELL_IOMMU_STRICT_PROTECTION
62 /* IOC mmap registers */
63 #define IOC_Reg_Size 0x2000
65 #define IOC_IOPT_CacheInvd 0x908
66 #define IOC_IOPT_CacheInvd_NE_Mask 0xffe0000000000000ul
67 #define IOC_IOPT_CacheInvd_IOPTE_Mask 0x000003fffffffff8ul
68 #define IOC_IOPT_CacheInvd_Busy 0x0000000000000001ul
70 #define IOC_IOST_Origin 0x918
71 #define IOC_IOST_Origin_E 0x8000000000000000ul
72 #define IOC_IOST_Origin_HW 0x0000000000000800ul
73 #define IOC_IOST_Origin_HL 0x0000000000000400ul
75 #define IOC_IO_ExcpStat 0x920
76 #define IOC_IO_ExcpStat_V 0x8000000000000000ul
77 #define IOC_IO_ExcpStat_SPF_Mask 0x6000000000000000ul
78 #define IOC_IO_ExcpStat_SPF_S 0x6000000000000000ul
79 #define IOC_IO_ExcpStat_SPF_P 0x2000000000000000ul
80 #define IOC_IO_ExcpStat_ADDR_Mask 0x00000007fffff000ul
81 #define IOC_IO_ExcpStat_RW_Mask 0x0000000000000800ul
82 #define IOC_IO_ExcpStat_IOID_Mask 0x00000000000007fful
84 #define IOC_IO_ExcpMask 0x928
85 #define IOC_IO_ExcpMask_SFE 0x4000000000000000ul
86 #define IOC_IO_ExcpMask_PFE 0x2000000000000000ul
88 #define IOC_IOCmd_Offset 0x1000
90 #define IOC_IOCmd_Cfg 0xc00
91 #define IOC_IOCmd_Cfg_TE 0x0000800000000000ul
94 /* Segment table entries */
95 #define IOSTE_V 0x8000000000000000ul /* valid */
96 #define IOSTE_H 0x4000000000000000ul /* cache hint */
97 #define IOSTE_PT_Base_RPN_Mask 0x3ffffffffffff000ul /* base RPN of IOPT */
98 #define IOSTE_NPPT_Mask 0x0000000000000fe0ul /* no. pages in IOPT */
99 #define IOSTE_PS_Mask 0x0000000000000007ul /* page size */
100 #define IOSTE_PS_4K 0x0000000000000001ul /* - 4kB */
101 #define IOSTE_PS_64K 0x0000000000000003ul /* - 64kB */
102 #define IOSTE_PS_1M 0x0000000000000005ul /* - 1MB */
103 #define IOSTE_PS_16M 0x0000000000000007ul /* - 16MB */
107 #define IO_SEGMENT_SHIFT 28
108 #define IO_PAGENO_BITS(shift) (IO_SEGMENT_SHIFT - (shift))
110 /* The high bit needs to be set on every DMA address */
111 #define SPIDER_DMA_OFFSET 0x80000000ul
113 struct iommu_window {
114 struct list_head list;
115 struct cbe_iommu *iommu;
116 unsigned long offset;
119 struct iommu_table table;
126 void __iomem *xlate_regs;
127 void __iomem *cmd_regs;
131 struct list_head windows;
134 /* Static array of iommus, one per node
135 * each contains a list of windows, keyed from dma_window property
136 * - on bus setup, look for a matching window, or create one
137 * - on dev setup, assign iommu_table ptr
139 static struct cbe_iommu iommus[NR_IOMMUS];
140 static int cbe_nr_iommus;
142 static void invalidate_tce_cache(struct cbe_iommu *iommu, unsigned long *pte,
149 reg = iommu->xlate_regs + IOC_IOPT_CacheInvd;
152 /* we can invalidate up to 1 << 11 PTEs at once */
153 n = min(n_ptes, 1l << 11);
154 val = (((n /*- 1*/) << 53) & IOC_IOPT_CacheInvd_NE_Mask)
155 | (__pa(pte) & IOC_IOPT_CacheInvd_IOPTE_Mask)
156 | IOC_IOPT_CacheInvd_Busy;
159 while (in_be64(reg) & IOC_IOPT_CacheInvd_Busy)
167 static int tce_build_cell(struct iommu_table *tbl, long index, long npages,
168 unsigned long uaddr, enum dma_data_direction direction,
172 unsigned long *io_pte, base_pte;
173 struct iommu_window *window =
174 container_of(tbl, struct iommu_window, table);
176 /* implementing proper protection causes problems with the spidernet
177 * driver - check mapping directions later, but allow read & write by
179 #ifdef CELL_IOMMU_STRICT_PROTECTION
180 /* to avoid referencing a global, we use a trick here to setup the
181 * protection bit. "prot" is setup to be 3 fields of 4 bits appended
182 * together for each of the 3 supported direction values. It is then
183 * shifted left so that the fields matching the desired direction
184 * lands on the appropriate bits, and other bits are masked out.
186 const unsigned long prot = 0xc48;
188 ((prot << (52 + 4 * direction)) &
189 (CBE_IOPTE_PP_W | CBE_IOPTE_PP_R)) |
190 CBE_IOPTE_M | CBE_IOPTE_SO_RW |
191 (window->ioid & CBE_IOPTE_IOID_Mask);
193 base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M |
194 CBE_IOPTE_SO_RW | (window->ioid & CBE_IOPTE_IOID_Mask);
196 if (unlikely(attrs & DMA_ATTR_WEAK_ORDERING))
197 base_pte &= ~CBE_IOPTE_SO_RW;
199 io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);
201 for (i = 0; i < npages; i++, uaddr += (1 << tbl->it_page_shift))
202 io_pte[i] = base_pte | (__pa(uaddr) & CBE_IOPTE_RPN_Mask);
206 invalidate_tce_cache(window->iommu, io_pte, npages);
208 pr_debug("tce_build_cell(index=%lx,n=%lx,dir=%d,base_pte=%lx)\n",
209 index, npages, direction, base_pte);
213 static void tce_free_cell(struct iommu_table *tbl, long index, long npages)
217 unsigned long *io_pte, pte;
218 struct iommu_window *window =
219 container_of(tbl, struct iommu_window, table);
221 pr_debug("tce_free_cell(index=%lx,n=%lx)\n", index, npages);
223 #ifdef CELL_IOMMU_REAL_UNMAP
226 /* spider bridge does PCI reads after freeing - insert a mapping
227 * to a scratch page instead of an invalid entry */
228 pte = CBE_IOPTE_PP_R | CBE_IOPTE_M | CBE_IOPTE_SO_RW |
229 __pa(window->iommu->pad_page) |
230 (window->ioid & CBE_IOPTE_IOID_Mask);
233 io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);
235 for (i = 0; i < npages; i++)
240 invalidate_tce_cache(window->iommu, io_pte, npages);
243 static irqreturn_t ioc_interrupt(int irq, void *data)
245 unsigned long stat, spf;
246 struct cbe_iommu *iommu = data;
248 stat = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat);
249 spf = stat & IOC_IO_ExcpStat_SPF_Mask;
251 /* Might want to rate limit it */
252 printk(KERN_ERR "iommu: DMA exception 0x%016lx\n", stat);
253 printk(KERN_ERR " V=%d, SPF=[%c%c], RW=%s, IOID=0x%04x\n",
254 !!(stat & IOC_IO_ExcpStat_V),
255 (spf == IOC_IO_ExcpStat_SPF_S) ? 'S' : ' ',
256 (spf == IOC_IO_ExcpStat_SPF_P) ? 'P' : ' ',
257 (stat & IOC_IO_ExcpStat_RW_Mask) ? "Read" : "Write",
258 (unsigned int)(stat & IOC_IO_ExcpStat_IOID_Mask));
259 printk(KERN_ERR " page=0x%016lx\n",
260 stat & IOC_IO_ExcpStat_ADDR_Mask);
262 /* clear interrupt */
263 stat &= ~IOC_IO_ExcpStat_V;
264 out_be64(iommu->xlate_regs + IOC_IO_ExcpStat, stat);
269 static int cell_iommu_find_ioc(int nid, unsigned long *base)
271 struct device_node *np;
276 /* First look for new style /be nodes */
277 for_each_node_by_name(np, "ioc") {
278 if (of_node_to_nid(np) != nid)
280 if (of_address_to_resource(np, 0, &r)) {
281 printk(KERN_ERR "iommu: can't get address for %pOF\n",
290 /* Ok, let's try the old way */
291 for_each_node_by_type(np, "cpu") {
292 const unsigned int *nidp;
293 const unsigned long *tmp;
295 nidp = of_get_property(np, "node-id", NULL);
296 if (nidp && *nidp == nid) {
297 tmp = of_get_property(np, "ioc-translation", NULL);
309 static void cell_iommu_setup_stab(struct cbe_iommu *iommu,
310 unsigned long dbase, unsigned long dsize,
311 unsigned long fbase, unsigned long fsize)
314 unsigned long segments, stab_size;
316 segments = max(dbase + dsize, fbase + fsize) >> IO_SEGMENT_SHIFT;
318 pr_debug("%s: iommu[%d]: segments: %lu\n",
319 __func__, iommu->nid, segments);
321 /* set up the segment table */
322 stab_size = segments * sizeof(unsigned long);
323 page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(stab_size));
325 iommu->stab = page_address(page);
326 memset(iommu->stab, 0, stab_size);
329 static unsigned long *cell_iommu_alloc_ptab(struct cbe_iommu *iommu,
330 unsigned long base, unsigned long size, unsigned long gap_base,
331 unsigned long gap_size, unsigned long page_shift)
335 unsigned long reg, segments, pages_per_segment, ptab_size,
336 n_pte_pages, start_seg, *ptab;
338 start_seg = base >> IO_SEGMENT_SHIFT;
339 segments = size >> IO_SEGMENT_SHIFT;
340 pages_per_segment = 1ull << IO_PAGENO_BITS(page_shift);
341 /* PTEs for each segment must start on a 4K boundary */
342 pages_per_segment = max(pages_per_segment,
343 (1 << 12) / sizeof(unsigned long));
345 ptab_size = segments * pages_per_segment * sizeof(unsigned long);
346 pr_debug("%s: iommu[%d]: ptab_size: %lu, order: %d\n", __func__,
347 iommu->nid, ptab_size, get_order(ptab_size));
348 page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(ptab_size));
351 ptab = page_address(page);
352 memset(ptab, 0, ptab_size);
354 /* number of 4K pages needed for a page table */
355 n_pte_pages = (pages_per_segment * sizeof(unsigned long)) >> 12;
357 pr_debug("%s: iommu[%d]: stab at %p, ptab at %p, n_pte_pages: %lu\n",
358 __func__, iommu->nid, iommu->stab, ptab,
361 /* initialise the STEs */
362 reg = IOSTE_V | ((n_pte_pages - 1) << 5);
364 switch (page_shift) {
365 case 12: reg |= IOSTE_PS_4K; break;
366 case 16: reg |= IOSTE_PS_64K; break;
367 case 20: reg |= IOSTE_PS_1M; break;
368 case 24: reg |= IOSTE_PS_16M; break;
372 gap_base = gap_base >> IO_SEGMENT_SHIFT;
373 gap_size = gap_size >> IO_SEGMENT_SHIFT;
375 pr_debug("Setting up IOMMU stab:\n");
376 for (i = start_seg; i < (start_seg + segments); i++) {
377 if (i >= gap_base && i < (gap_base + gap_size)) {
378 pr_debug("\toverlap at %d, skipping\n", i);
381 iommu->stab[i] = reg | (__pa(ptab) + (n_pte_pages << 12) *
383 pr_debug("\t[%d] 0x%016lx\n", i, iommu->stab[i]);
389 static void cell_iommu_enable_hardware(struct cbe_iommu *iommu)
392 unsigned long reg, xlate_base;
395 if (cell_iommu_find_ioc(iommu->nid, &xlate_base))
396 panic("%s: missing IOC register mappings for node %d\n",
397 __func__, iommu->nid);
399 iommu->xlate_regs = ioremap(xlate_base, IOC_Reg_Size);
400 iommu->cmd_regs = iommu->xlate_regs + IOC_IOCmd_Offset;
402 /* ensure that the STEs have updated */
405 /* setup interrupts for the iommu. */
406 reg = in_be64(iommu->xlate_regs + IOC_IO_ExcpStat);
407 out_be64(iommu->xlate_regs + IOC_IO_ExcpStat,
408 reg & ~IOC_IO_ExcpStat_V);
409 out_be64(iommu->xlate_regs + IOC_IO_ExcpMask,
410 IOC_IO_ExcpMask_PFE | IOC_IO_ExcpMask_SFE);
412 virq = irq_create_mapping(NULL,
413 IIC_IRQ_IOEX_ATI | (iommu->nid << IIC_IRQ_NODE_SHIFT));
416 ret = request_irq(virq, ioc_interrupt, 0, iommu->name, iommu);
419 /* set the IOC segment table origin register (and turn on the iommu) */
420 reg = IOC_IOST_Origin_E | __pa(iommu->stab) | IOC_IOST_Origin_HW;
421 out_be64(iommu->xlate_regs + IOC_IOST_Origin, reg);
422 in_be64(iommu->xlate_regs + IOC_IOST_Origin);
424 /* turn on IO translation */
425 reg = in_be64(iommu->cmd_regs + IOC_IOCmd_Cfg) | IOC_IOCmd_Cfg_TE;
426 out_be64(iommu->cmd_regs + IOC_IOCmd_Cfg, reg);
429 static void cell_iommu_setup_hardware(struct cbe_iommu *iommu,
430 unsigned long base, unsigned long size)
432 cell_iommu_setup_stab(iommu, base, size, 0, 0);
433 iommu->ptab = cell_iommu_alloc_ptab(iommu, base, size, 0, 0,
434 IOMMU_PAGE_SHIFT_4K);
435 cell_iommu_enable_hardware(iommu);
438 #if 0/* Unused for now */
439 static struct iommu_window *find_window(struct cbe_iommu *iommu,
440 unsigned long offset, unsigned long size)
442 struct iommu_window *window;
444 /* todo: check for overlapping (but not equal) windows) */
446 list_for_each_entry(window, &(iommu->windows), list) {
447 if (window->offset == offset && window->size == size)
455 static inline u32 cell_iommu_get_ioid(struct device_node *np)
459 ioid = of_get_property(np, "ioid", NULL);
461 printk(KERN_WARNING "iommu: missing ioid for %pOF using 0\n",
469 static struct iommu_table_ops cell_iommu_ops = {
470 .set = tce_build_cell,
471 .clear = tce_free_cell
474 static struct iommu_window * __init
475 cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np,
476 unsigned long offset, unsigned long size,
477 unsigned long pte_offset)
479 struct iommu_window *window;
483 ioid = cell_iommu_get_ioid(np);
485 window = kzalloc_node(sizeof(*window), GFP_KERNEL, iommu->nid);
486 BUG_ON(window == NULL);
488 window->offset = offset;
491 window->iommu = iommu;
493 window->table.it_blocksize = 16;
494 window->table.it_base = (unsigned long)iommu->ptab;
495 window->table.it_index = iommu->nid;
496 window->table.it_page_shift = IOMMU_PAGE_SHIFT_4K;
497 window->table.it_offset =
498 (offset >> window->table.it_page_shift) + pte_offset;
499 window->table.it_size = size >> window->table.it_page_shift;
500 window->table.it_ops = &cell_iommu_ops;
502 iommu_init_table(&window->table, iommu->nid);
504 pr_debug("\tioid %d\n", window->ioid);
505 pr_debug("\tblocksize %ld\n", window->table.it_blocksize);
506 pr_debug("\tbase 0x%016lx\n", window->table.it_base);
507 pr_debug("\toffset 0x%lx\n", window->table.it_offset);
508 pr_debug("\tsize %ld\n", window->table.it_size);
510 list_add(&window->list, &iommu->windows);
515 /* We need to map and reserve the first IOMMU page since it's used
516 * by the spider workaround. In theory, we only need to do that when
517 * running on spider but it doesn't really matter.
519 * This code also assumes that we have a window that starts at 0,
520 * which is the case on all spider based blades.
522 page = alloc_pages_node(iommu->nid, GFP_KERNEL, 0);
524 iommu->pad_page = page_address(page);
525 clear_page(iommu->pad_page);
527 __set_bit(0, window->table.it_map);
528 tce_build_cell(&window->table, window->table.it_offset, 1,
529 (unsigned long)iommu->pad_page, DMA_TO_DEVICE, 0);
534 static struct cbe_iommu *cell_iommu_for_node(int nid)
538 for (i = 0; i < cbe_nr_iommus; i++)
539 if (iommus[i].nid == nid)
544 static unsigned long cell_dma_nommu_offset;
546 static unsigned long dma_iommu_fixed_base;
548 /* iommu_fixed_is_weak is set if booted with iommu_fixed=weak */
549 bool iommu_fixed_is_weak;
551 static struct iommu_table *cell_get_iommu_table(struct device *dev)
553 struct iommu_window *window;
554 struct cbe_iommu *iommu;
556 /* Current implementation uses the first window available in that
557 * node's iommu. We -might- do something smarter later though it may
560 iommu = cell_iommu_for_node(dev_to_node(dev));
561 if (iommu == NULL || list_empty(&iommu->windows)) {
562 dev_err(dev, "iommu: missing iommu for %pOF (node %d)\n",
563 dev->of_node, dev_to_node(dev));
566 window = list_entry(iommu->windows.next, struct iommu_window, list);
568 return &window->table;
571 static u64 cell_iommu_get_fixed_address(struct device *dev);
573 static void cell_dma_dev_setup(struct device *dev)
575 if (get_pci_dma_ops() == &dma_iommu_ops) {
576 u64 addr = cell_iommu_get_fixed_address(dev);
578 if (addr != OF_BAD_ADDR)
579 set_dma_offset(dev, addr + dma_iommu_fixed_base);
580 set_iommu_table_base(dev, cell_get_iommu_table(dev));
581 } else if (get_pci_dma_ops() == &dma_nommu_ops) {
582 set_dma_offset(dev, cell_dma_nommu_offset);
588 static void cell_pci_dma_dev_setup(struct pci_dev *dev)
590 cell_dma_dev_setup(&dev->dev);
593 static int cell_of_bus_notify(struct notifier_block *nb, unsigned long action,
596 struct device *dev = data;
598 /* We are only intereted in device addition */
599 if (action != BUS_NOTIFY_ADD_DEVICE)
602 /* We use the PCI DMA ops */
603 dev->dma_ops = get_pci_dma_ops();
605 cell_dma_dev_setup(dev);
610 static struct notifier_block cell_of_bus_notifier = {
611 .notifier_call = cell_of_bus_notify
614 static int __init cell_iommu_get_window(struct device_node *np,
618 const __be32 *dma_window;
621 /* Use ibm,dma-window if available, else, hard code ! */
622 dma_window = of_get_property(np, "ibm,dma-window", NULL);
623 if (dma_window == NULL) {
629 of_parse_dma_window(np, dma_window, &index, base, size);
633 static struct cbe_iommu * __init cell_iommu_alloc(struct device_node *np)
635 struct cbe_iommu *iommu;
639 nid = of_node_to_nid(np);
641 printk(KERN_ERR "iommu: failed to get node for %pOF\n",
645 pr_debug("iommu: setting up iommu for node %d (%pOF)\n",
648 /* XXX todo: If we can have multiple windows on the same IOMMU, which
649 * isn't the case today, we probably want here to check whether the
650 * iommu for that node is already setup.
651 * However, there might be issue with getting the size right so let's
652 * ignore that for now. We might want to completely get rid of the
653 * multiple window support since the cell iommu supports per-page ioids
656 if (cbe_nr_iommus >= NR_IOMMUS) {
657 printk(KERN_ERR "iommu: too many IOMMUs detected ! (%pOF)\n",
662 /* Init base fields */
667 snprintf(iommu->name, sizeof(iommu->name), "iommu%d", i);
668 INIT_LIST_HEAD(&iommu->windows);
673 static void __init cell_iommu_init_one(struct device_node *np,
674 unsigned long offset)
676 struct cbe_iommu *iommu;
677 unsigned long base, size;
679 iommu = cell_iommu_alloc(np);
683 /* Obtain a window for it */
684 cell_iommu_get_window(np, &base, &size);
686 pr_debug("\ttranslating window 0x%lx...0x%lx\n",
687 base, base + size - 1);
689 /* Initialize the hardware */
690 cell_iommu_setup_hardware(iommu, base, size);
692 /* Setup the iommu_table */
693 cell_iommu_setup_window(iommu, np, base, size,
694 offset >> IOMMU_PAGE_SHIFT_4K);
697 static void __init cell_disable_iommus(void)
700 unsigned long base, val;
701 void __iomem *xregs, *cregs;
703 /* Make sure IOC translation is disabled on all nodes */
704 for_each_online_node(node) {
705 if (cell_iommu_find_ioc(node, &base))
707 xregs = ioremap(base, IOC_Reg_Size);
710 cregs = xregs + IOC_IOCmd_Offset;
712 pr_debug("iommu: cleaning up iommu on node %d\n", node);
714 out_be64(xregs + IOC_IOST_Origin, 0);
715 (void)in_be64(xregs + IOC_IOST_Origin);
716 val = in_be64(cregs + IOC_IOCmd_Cfg);
717 val &= ~IOC_IOCmd_Cfg_TE;
718 out_be64(cregs + IOC_IOCmd_Cfg, val);
719 (void)in_be64(cregs + IOC_IOCmd_Cfg);
725 static int __init cell_iommu_init_disabled(void)
727 struct device_node *np = NULL;
728 unsigned long base = 0, size;
730 /* When no iommu is present, we use direct DMA ops */
731 set_pci_dma_ops(&dma_nommu_ops);
733 /* First make sure all IOC translation is turned off */
734 cell_disable_iommus();
736 /* If we have no Axon, we set up the spider DMA magic offset */
737 if (of_find_node_by_name(NULL, "axon") == NULL)
738 cell_dma_nommu_offset = SPIDER_DMA_OFFSET;
740 /* Now we need to check to see where the memory is mapped
741 * in PCI space. We assume that all busses use the same dma
742 * window which is always the case so far on Cell, thus we
743 * pick up the first pci-internal node we can find and check
744 * the DMA window from there.
746 for_each_node_by_name(np, "axon") {
747 if (np->parent == NULL || np->parent->parent != NULL)
749 if (cell_iommu_get_window(np, &base, &size) == 0)
753 for_each_node_by_name(np, "pci-internal") {
754 if (np->parent == NULL || np->parent->parent != NULL)
756 if (cell_iommu_get_window(np, &base, &size) == 0)
762 /* If we found a DMA window, we check if it's big enough to enclose
763 * all of physical memory. If not, we force enable IOMMU
765 if (np && size < memblock_end_of_DRAM()) {
766 printk(KERN_WARNING "iommu: force-enabled, dma window"
767 " (%ldMB) smaller than total memory (%lldMB)\n",
768 size >> 20, memblock_end_of_DRAM() >> 20);
772 cell_dma_nommu_offset += base;
774 if (cell_dma_nommu_offset != 0)
775 cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup;
777 printk("iommu: disabled, direct DMA offset is 0x%lx\n",
778 cell_dma_nommu_offset);
784 * Fixed IOMMU mapping support
786 * This code adds support for setting up a fixed IOMMU mapping on certain
787 * cell machines. For 64-bit devices this avoids the performance overhead of
788 * mapping and unmapping pages at runtime. 32-bit devices are unable to use
791 * The fixed mapping is established at boot, and maps all of physical memory
792 * 1:1 into device space at some offset. On machines with < 30 GB of memory
793 * we setup the fixed mapping immediately above the normal IOMMU window.
795 * For example a machine with 4GB of memory would end up with the normal
796 * IOMMU window from 0-2GB and the fixed mapping window from 2GB to 6GB. In
797 * this case a 64-bit device wishing to DMA to 1GB would be told to DMA to
798 * 3GB, plus any offset required by firmware. The firmware offset is encoded
799 * in the "dma-ranges" property.
801 * On machines with 30GB or more of memory, we are unable to place the fixed
802 * mapping above the normal IOMMU window as we would run out of address space.
803 * Instead we move the normal IOMMU window to coincide with the hash page
804 * table, this region does not need to be part of the fixed mapping as no
805 * device should ever be DMA'ing to it. We then setup the fixed mapping
809 static u64 cell_iommu_get_fixed_address(struct device *dev)
811 u64 cpu_addr, size, best_size, dev_addr = OF_BAD_ADDR;
812 struct device_node *np;
813 const u32 *ranges = NULL;
814 int i, len, best, naddr, nsize, pna, range_size;
816 /* We can be called for platform devices that have no of_node */
817 np = of_node_get(dev->of_node);
822 naddr = of_n_addr_cells(np);
823 nsize = of_n_size_cells(np);
824 np = of_get_next_parent(np);
828 ranges = of_get_property(np, "dma-ranges", &len);
830 /* Ignore empty ranges, they imply no translation required */
831 if (ranges && len > 0)
836 dev_dbg(dev, "iommu: no dma-ranges found\n");
842 pna = of_n_addr_cells(np);
843 range_size = naddr + nsize + pna;
845 /* dma-ranges format:
846 * child addr : naddr cells
847 * parent addr : pna cells
850 for (i = 0, best = -1, best_size = 0; i < len; i += range_size) {
851 cpu_addr = of_translate_dma_address(np, ranges + i + naddr);
852 size = of_read_number(ranges + i + naddr + pna, nsize);
854 if (cpu_addr == 0 && size > best_size) {
861 dev_addr = of_read_number(ranges + best, naddr);
863 dev_dbg(dev, "iommu: no suitable range found!\n");
871 static bool cell_pci_iommu_bypass_supported(struct pci_dev *pdev, u64 mask)
873 return mask == DMA_BIT_MASK(64) &&
874 cell_iommu_get_fixed_address(&pdev->dev) != OF_BAD_ADDR;
877 static void insert_16M_pte(unsigned long addr, unsigned long *ptab,
878 unsigned long base_pte)
880 unsigned long segment, offset;
882 segment = addr >> IO_SEGMENT_SHIFT;
883 offset = (addr >> 24) - (segment << IO_PAGENO_BITS(24));
884 ptab = ptab + (segment * (1 << 12) / sizeof(unsigned long));
886 pr_debug("iommu: addr %lx ptab %p segment %lx offset %lx\n",
887 addr, ptab, segment, offset);
889 ptab[offset] = base_pte | (__pa(addr) & CBE_IOPTE_RPN_Mask);
892 static void cell_iommu_setup_fixed_ptab(struct cbe_iommu *iommu,
893 struct device_node *np, unsigned long dbase, unsigned long dsize,
894 unsigned long fbase, unsigned long fsize)
896 unsigned long base_pte, uaddr, ioaddr, *ptab;
898 ptab = cell_iommu_alloc_ptab(iommu, fbase, fsize, dbase, dsize, 24);
900 dma_iommu_fixed_base = fbase;
902 pr_debug("iommu: mapping 0x%lx pages from 0x%lx\n", fsize, fbase);
904 base_pte = CBE_IOPTE_PP_W | CBE_IOPTE_PP_R | CBE_IOPTE_M |
905 (cell_iommu_get_ioid(np) & CBE_IOPTE_IOID_Mask);
907 if (iommu_fixed_is_weak)
908 pr_info("IOMMU: Using weak ordering for fixed mapping\n");
910 pr_info("IOMMU: Using strong ordering for fixed mapping\n");
911 base_pte |= CBE_IOPTE_SO_RW;
914 for (uaddr = 0; uaddr < fsize; uaddr += (1 << 24)) {
915 /* Don't touch the dynamic region */
916 ioaddr = uaddr + fbase;
917 if (ioaddr >= dbase && ioaddr < (dbase + dsize)) {
918 pr_debug("iommu: fixed/dynamic overlap, skipping\n");
922 insert_16M_pte(uaddr, ptab, base_pte);
928 static int __init cell_iommu_fixed_mapping_init(void)
930 unsigned long dbase, dsize, fbase, fsize, hbase, hend;
931 struct cbe_iommu *iommu;
932 struct device_node *np;
934 /* The fixed mapping is only supported on axon machines */
935 np = of_find_node_by_name(NULL, "axon");
939 pr_debug("iommu: fixed mapping disabled, no axons found\n");
943 /* We must have dma-ranges properties for fixed mapping to work */
944 np = of_find_node_with_property(NULL, "dma-ranges");
948 pr_debug("iommu: no dma-ranges found, no fixed mapping\n");
952 /* The default setup is to have the fixed mapping sit after the
953 * dynamic region, so find the top of the largest IOMMU window
954 * on any axon, then add the size of RAM and that's our max value.
955 * If that is > 32GB we have to do other shennanigans.
958 for_each_node_by_name(np, "axon") {
959 cell_iommu_get_window(np, &dbase, &dsize);
960 fbase = max(fbase, dbase + dsize);
963 fbase = _ALIGN_UP(fbase, 1 << IO_SEGMENT_SHIFT);
964 fsize = memblock_phys_mem_size();
966 if ((fbase + fsize) <= 0x800000000ul)
967 hbase = 0; /* use the device tree window */
969 /* If we're over 32 GB we need to cheat. We can't map all of
970 * RAM with the fixed mapping, and also fit the dynamic
971 * region. So try to place the dynamic region where the hash
972 * table sits, drivers never need to DMA to it, we don't
973 * need a fixed mapping for that area.
976 pr_debug("iommu: htab is NULL, on LPAR? Huh?\n");
979 hbase = __pa(htab_address);
980 hend = hbase + htab_size_bytes;
982 /* The window must start and end on a segment boundary */
983 if ((hbase != _ALIGN_UP(hbase, 1 << IO_SEGMENT_SHIFT)) ||
984 (hend != _ALIGN_UP(hend, 1 << IO_SEGMENT_SHIFT))) {
985 pr_debug("iommu: hash window not segment aligned\n");
989 /* Check the hash window fits inside the real DMA window */
990 for_each_node_by_name(np, "axon") {
991 cell_iommu_get_window(np, &dbase, &dsize);
993 if (hbase < dbase || (hend > (dbase + dsize))) {
994 pr_debug("iommu: hash window doesn't fit in"
995 "real DMA window\n");
1003 /* Setup the dynamic regions */
1004 for_each_node_by_name(np, "axon") {
1005 iommu = cell_iommu_alloc(np);
1009 cell_iommu_get_window(np, &dbase, &dsize);
1012 dsize = htab_size_bytes;
1015 printk(KERN_DEBUG "iommu: node %d, dynamic window 0x%lx-0x%lx "
1016 "fixed window 0x%lx-0x%lx\n", iommu->nid, dbase,
1017 dbase + dsize, fbase, fbase + fsize);
1019 cell_iommu_setup_stab(iommu, dbase, dsize, fbase, fsize);
1020 iommu->ptab = cell_iommu_alloc_ptab(iommu, dbase, dsize, 0, 0,
1021 IOMMU_PAGE_SHIFT_4K);
1022 cell_iommu_setup_fixed_ptab(iommu, np, dbase, dsize,
1024 cell_iommu_enable_hardware(iommu);
1025 cell_iommu_setup_window(iommu, np, dbase, dsize, 0);
1028 cell_pci_controller_ops.iommu_bypass_supported =
1029 cell_pci_iommu_bypass_supported;
1033 static int iommu_fixed_disabled;
1035 static int __init setup_iommu_fixed(char *str)
1037 struct device_node *pciep;
1039 if (strcmp(str, "off") == 0)
1040 iommu_fixed_disabled = 1;
1042 /* If we can find a pcie-endpoint in the device tree assume that
1043 * we're on a triblade or a CAB so by default the fixed mapping
1044 * should be set to be weakly ordered; but only if the boot
1045 * option WASN'T set for strong ordering
1047 pciep = of_find_node_by_type(NULL, "pcie-endpoint");
1049 if (strcmp(str, "weak") == 0 || (pciep && strcmp(str, "strong") != 0))
1050 iommu_fixed_is_weak = true;
1056 __setup("iommu_fixed=", setup_iommu_fixed);
1058 static int __init cell_iommu_init(void)
1060 struct device_node *np;
1062 /* If IOMMU is disabled or we have little enough RAM to not need
1063 * to enable it, we setup a direct mapping.
1065 * Note: should we make sure we have the IOMMU actually disabled ?
1068 (!iommu_force_on && memblock_end_of_DRAM() <= 0x80000000ull))
1069 if (cell_iommu_init_disabled() == 0)
1072 /* Setup various callbacks */
1073 cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup;
1075 if (!iommu_fixed_disabled && cell_iommu_fixed_mapping_init() == 0)
1078 /* Create an iommu for each /axon node. */
1079 for_each_node_by_name(np, "axon") {
1080 if (np->parent == NULL || np->parent->parent != NULL)
1082 cell_iommu_init_one(np, 0);
1085 /* Create an iommu for each toplevel /pci-internal node for
1086 * old hardware/firmware
1088 for_each_node_by_name(np, "pci-internal") {
1089 if (np->parent == NULL || np->parent->parent != NULL)
1091 cell_iommu_init_one(np, SPIDER_DMA_OFFSET);
1094 /* Setup default PCI iommu ops */
1095 set_pci_dma_ops(&dma_iommu_ops);
1098 /* Register callbacks on OF platform device addition/removal
1099 * to handle linking them to the right DMA operations
1101 bus_register_notifier(&platform_bus_type, &cell_of_bus_notifier);
1105 machine_arch_initcall(cell, cell_iommu_init);