xref: /linux/drivers/parisc/ccio-dma.c (revision af873fcecef567abf8a3468b06dd4e4aab46da6d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 ** ccio-dma.c:
4 **	DMA management routines for first generation cache-coherent machines.
5 **	Program U2/Uturn in "Virtual Mode" and use the I/O MMU.
6 **
7 **	(c) Copyright 2000 Grant Grundler
8 **	(c) Copyright 2000 Ryan Bradetich
9 **	(c) Copyright 2000 Hewlett-Packard Company
10 **
11 **
12 **
13 **  "Real Mode" operation refers to U2/Uturn chip operation.
14 **  U2/Uturn were designed to perform coherency checks w/o using
15 **  the I/O MMU - basically what x86 does.
16 **
17 **  Philipp Rumpf has a "Real Mode" driver for PCX-W machines at:
18 **      CVSROOT=:pserver:anonymous@198.186.203.37:/cvsroot/linux-parisc
19 **      cvs -z3 co linux/arch/parisc/kernel/dma-rm.c
20 **
21 **  I've rewritten his code to work under TPG's tree. See ccio-rm-dma.c.
22 **
23 **  Drawbacks of using Real Mode are:
24 **	o outbound DMA is slower - U2 won't prefetch data (GSC+ XQL signal).
25 **      o Inbound DMA less efficient - U2 can't use DMA_FAST attribute.
26 **	o Ability to do scatter/gather in HW is lost.
27 **	o Doesn't work under PCX-U/U+ machines since they didn't follow
28 **        the coherency design originally worked out. Only PCX-W does.
29 */
30 
31 #include <linux/types.h>
32 #include <linux/kernel.h>
33 #include <linux/init.h>
34 #include <linux/mm.h>
35 #include <linux/spinlock.h>
36 #include <linux/slab.h>
37 #include <linux/string.h>
38 #include <linux/pci.h>
39 #include <linux/reboot.h>
40 #include <linux/proc_fs.h>
41 #include <linux/seq_file.h>
42 #include <linux/scatterlist.h>
43 #include <linux/iommu-helper.h>
44 #include <linux/export.h>
45 
46 #include <asm/byteorder.h>
47 #include <asm/cache.h>		/* for L1_CACHE_BYTES */
48 #include <linux/uaccess.h>
49 #include <asm/page.h>
50 #include <asm/dma.h>
51 #include <asm/io.h>
52 #include <asm/hardware.h>       /* for register_module() */
53 #include <asm/parisc-device.h>
54 
55 #include "iommu.h"
56 
57 /*
58 ** Choose "ccio" since that's what HP-UX calls it.
59 ** Make it easier for folks to migrate from one to the other :^)
60 */
61 #define MODULE_NAME "ccio"
62 
63 #undef DEBUG_CCIO_RES
64 #undef DEBUG_CCIO_RUN
65 #undef DEBUG_CCIO_INIT
66 #undef DEBUG_CCIO_RUN_SG
67 
68 #ifdef CONFIG_PROC_FS
69 /* depends on proc fs support. But costs CPU performance. */
70 #undef CCIO_COLLECT_STATS
71 #endif
72 
73 #include <asm/runway.h>		/* for proc_runway_root */
74 
75 #ifdef DEBUG_CCIO_INIT
76 #define DBG_INIT(x...)  printk(x)
77 #else
78 #define DBG_INIT(x...)
79 #endif
80 
81 #ifdef DEBUG_CCIO_RUN
82 #define DBG_RUN(x...)   printk(x)
83 #else
84 #define DBG_RUN(x...)
85 #endif
86 
87 #ifdef DEBUG_CCIO_RES
88 #define DBG_RES(x...)   printk(x)
89 #else
90 #define DBG_RES(x...)
91 #endif
92 
93 #ifdef DEBUG_CCIO_RUN_SG
94 #define DBG_RUN_SG(x...) printk(x)
95 #else
96 #define DBG_RUN_SG(x...)
97 #endif
98 
99 #define CCIO_INLINE	inline
100 #define WRITE_U32(value, addr) __raw_writel(value, addr)
101 #define READ_U32(addr) __raw_readl(addr)
102 
103 #define U2_IOA_RUNWAY 0x580
104 #define U2_BC_GSC     0x501
105 #define UTURN_IOA_RUNWAY 0x581
106 #define UTURN_BC_GSC     0x502
107 
108 #define IOA_NORMAL_MODE      0x00020080 /* IO_CONTROL to turn on CCIO        */
109 #define CMD_TLB_DIRECT_WRITE 35         /* IO_COMMAND for I/O TLB Writes     */
110 #define CMD_TLB_PURGE        33         /* IO_COMMAND to Purge I/O TLB entry */
111 
112 struct ioa_registers {
113         /* Runway Supervisory Set */
114         int32_t    unused1[12];
115         uint32_t   io_command;             /* Offset 12 */
116         uint32_t   io_status;              /* Offset 13 */
117         uint32_t   io_control;             /* Offset 14 */
118         int32_t    unused2[1];
119 
120         /* Runway Auxiliary Register Set */
121         uint32_t   io_err_resp;            /* Offset  0 */
122         uint32_t   io_err_info;            /* Offset  1 */
123         uint32_t   io_err_req;             /* Offset  2 */
124         uint32_t   io_err_resp_hi;         /* Offset  3 */
125         uint32_t   io_tlb_entry_m;         /* Offset  4 */
126         uint32_t   io_tlb_entry_l;         /* Offset  5 */
127         uint32_t   unused3[1];
128         uint32_t   io_pdir_base;           /* Offset  7 */
129         uint32_t   io_io_low_hv;           /* Offset  8 */
130         uint32_t   io_io_high_hv;          /* Offset  9 */
131         uint32_t   unused4[1];
132         uint32_t   io_chain_id_mask;       /* Offset 11 */
133         uint32_t   unused5[2];
134         uint32_t   io_io_low;              /* Offset 14 */
135         uint32_t   io_io_high;             /* Offset 15 */
136 };
137 
138 /*
139 ** IOA Registers
140 ** -------------
141 **
142 ** Runway IO_CONTROL Register (+0x38)
143 **
144 ** The Runway IO_CONTROL register controls the forwarding of transactions.
145 **
146 ** | 0  ...  13  |  14 15 | 16 ... 21 | 22 | 23 24 |  25 ... 31 |
147 ** |    HV       |   TLB  |  reserved | HV | mode  |  reserved  |
148 **
149 ** o mode field indicates the address translation of transactions
150 **   forwarded from Runway to GSC+:
151 **       Mode Name     Value        Definition
152 **       Off (default)   0          Opaque to matching addresses.
153 **       Include         1          Transparent for matching addresses.
154 **       Peek            3          Map matching addresses.
155 **
156 **       + "Off" mode: Runway transactions which match the I/O range
157 **         specified by the IO_IO_LOW/IO_IO_HIGH registers will be ignored.
158 **       + "Include" mode: all addresses within the I/O range specified
159 **         by the IO_IO_LOW and IO_IO_HIGH registers are transparently
160 **         forwarded. This is the I/O Adapter's normal operating mode.
161 **       + "Peek" mode: used during system configuration to initialize the
162 **         GSC+ bus. Runway Write_Shorts in the address range specified by
163 **         IO_IO_LOW and IO_IO_HIGH are forwarded through the I/O Adapter
164 **         *AND* the GSC+ address is remapped to the Broadcast Physical
165 **         Address space by setting the 14 high order address bits of the
166 **         32 bit GSC+ address to ones.
167 **
168 ** o TLB field affects transactions which are forwarded from GSC+ to Runway.
169 **   "Real" mode is the poweron default.
170 **
171 **   TLB Mode  Value  Description
172 **   Real        0    No TLB translation. Address is directly mapped and the
173 **                    virtual address is composed of selected physical bits.
174 **   Error       1    Software fills the TLB manually.
175 **   Normal      2    IOA fetches IO TLB misses from IO PDIR (in host memory).
176 **
177 **
178 ** IO_IO_LOW_HV	  +0x60 (HV dependent)
179 ** IO_IO_HIGH_HV  +0x64 (HV dependent)
180 ** IO_IO_LOW      +0x78	(Architected register)
181 ** IO_IO_HIGH     +0x7c	(Architected register)
182 **
183 ** IO_IO_LOW and IO_IO_HIGH set the lower and upper bounds of the
184 ** I/O Adapter address space, respectively.
185 **
186 ** 0  ... 7 | 8 ... 15 |  16   ...   31 |
187 ** 11111111 | 11111111 |      address   |
188 **
189 ** Each LOW/HIGH pair describes a disjoint address space region.
190 ** (2 per GSC+ port). Each incoming Runway transaction address is compared
191 ** with both sets of LOW/HIGH registers. If the address is in the range
192 ** greater than or equal to IO_IO_LOW and less than IO_IO_HIGH the transaction
193 ** for forwarded to the respective GSC+ bus.
194 ** Specify IO_IO_LOW equal to or greater than IO_IO_HIGH to avoid specifying
195 ** an address space region.
196 **
197 ** In order for a Runway address to reside within GSC+ extended address space:
198 **	Runway Address [0:7]    must identically compare to 8'b11111111
199 **	Runway Address [8:11]   must be equal to IO_IO_LOW(_HV)[16:19]
200 ** 	Runway Address [12:23]  must be greater than or equal to
201 **	           IO_IO_LOW(_HV)[20:31] and less than IO_IO_HIGH(_HV)[20:31].
202 **	Runway Address [24:39]  is not used in the comparison.
203 **
204 ** When the Runway transaction is forwarded to GSC+, the GSC+ address is
205 ** as follows:
206 **	GSC+ Address[0:3]	4'b1111
207 **	GSC+ Address[4:29]	Runway Address[12:37]
208 **	GSC+ Address[30:31]	2'b00
209 **
210 ** All 4 Low/High registers must be initialized (by PDC) once the lower bus
211 ** is interrogated and address space is defined. The operating system will
212 ** modify the architectural IO_IO_LOW and IO_IO_HIGH registers following
213 ** the PDC initialization.  However, the hardware version dependent IO_IO_LOW
214 ** and IO_IO_HIGH registers should not be subsequently altered by the OS.
215 **
216 ** Writes to both sets of registers will take effect immediately, bypassing
217 ** the queues, which ensures that subsequent Runway transactions are checked
218 ** against the updated bounds values. However reads are queued, introducing
219 ** the possibility of a read being bypassed by a subsequent write to the same
220 ** register. This sequence can be avoided by having software wait for read
221 ** returns before issuing subsequent writes.
222 */
223 
224 struct ioc {
225 	struct ioa_registers __iomem *ioc_regs;  /* I/O MMU base address */
226 	u8  *res_map;	                /* resource map, bit == pdir entry */
227 	u64 *pdir_base;	                /* physical base address */
228 	u32 pdir_size; 			/* bytes, function of IOV Space size */
229 	u32 res_hint;	                /* next available IOVP -
230 					   circular search */
231 	u32 res_size;		    	/* size of resource map in bytes */
232 	spinlock_t res_lock;
233 
234 #ifdef CCIO_COLLECT_STATS
235 #define CCIO_SEARCH_SAMPLE 0x100
236 	unsigned long avg_search[CCIO_SEARCH_SAMPLE];
237 	unsigned long avg_idx;		  /* current index into avg_search */
238 	unsigned long used_pages;
239 	unsigned long msingle_calls;
240 	unsigned long msingle_pages;
241 	unsigned long msg_calls;
242 	unsigned long msg_pages;
243 	unsigned long usingle_calls;
244 	unsigned long usingle_pages;
245 	unsigned long usg_calls;
246 	unsigned long usg_pages;
247 #endif
248 	unsigned short cujo20_bug;
249 
250 	/* STUFF We don't need in performance path */
251 	u32 chainid_shift; 		/* specify bit location of chain_id */
252 	struct ioc *next;		/* Linked list of discovered iocs */
253 	const char *name;		/* device name from firmware */
254 	unsigned int hw_path;           /* the hardware path this ioc is associatd with */
255 	struct pci_dev *fake_pci_dev;   /* the fake pci_dev for non-pci devs */
256 	struct resource mmio_region[2]; /* The "routed" MMIO regions */
257 };
258 
259 static struct ioc *ioc_list;
260 static int ioc_count;
261 
262 /**************************************************************
263 *
264 *   I/O Pdir Resource Management
265 *
266 *   Bits set in the resource map are in use.
267 *   Each bit can represent a number of pages.
268 *   LSbs represent lower addresses (IOVA's).
269 *
270 *   This was was copied from sba_iommu.c. Don't try to unify
271 *   the two resource managers unless a way to have different
272 *   allocation policies is also adjusted. We'd like to avoid
273 *   I/O TLB thrashing by having resource allocation policy
274 *   match the I/O TLB replacement policy.
275 *
276 ***************************************************************/
277 #define IOVP_SIZE PAGE_SIZE
278 #define IOVP_SHIFT PAGE_SHIFT
279 #define IOVP_MASK PAGE_MASK
280 
281 /* Convert from IOVP to IOVA and vice versa. */
282 #define CCIO_IOVA(iovp,offset) ((iovp) | (offset))
283 #define CCIO_IOVP(iova) ((iova) & IOVP_MASK)
284 
285 #define PDIR_INDEX(iovp)    ((iovp)>>IOVP_SHIFT)
286 #define MKIOVP(pdir_idx)    ((long)(pdir_idx) << IOVP_SHIFT)
287 #define MKIOVA(iovp,offset) (dma_addr_t)((long)iovp | (long)offset)
288 
289 /*
290 ** Don't worry about the 150% average search length on a miss.
291 ** If the search wraps around, and passes the res_hint, it will
292 ** cause the kernel to panic anyhow.
293 */
294 #define CCIO_SEARCH_LOOP(ioc, res_idx, mask, size)  \
295        for(; res_ptr < res_end; ++res_ptr) { \
296 		int ret;\
297 		unsigned int idx;\
298 		idx = (unsigned int)((unsigned long)res_ptr - (unsigned long)ioc->res_map); \
299 		ret = iommu_is_span_boundary(idx << 3, pages_needed, 0, boundary_size);\
300 		if ((0 == (*res_ptr & mask)) && !ret) { \
301 			*res_ptr |= mask; \
302 			res_idx = idx;\
303 			ioc->res_hint = res_idx + (size >> 3); \
304 			goto resource_found; \
305 		} \
306 	}
307 
308 #define CCIO_FIND_FREE_MAPPING(ioa, res_idx, mask, size) \
309        u##size *res_ptr = (u##size *)&((ioc)->res_map[ioa->res_hint & ~((size >> 3) - 1)]); \
310        u##size *res_end = (u##size *)&(ioc)->res_map[ioa->res_size]; \
311        CCIO_SEARCH_LOOP(ioc, res_idx, mask, size); \
312        res_ptr = (u##size *)&(ioc)->res_map[0]; \
313        CCIO_SEARCH_LOOP(ioa, res_idx, mask, size);
314 
315 /*
316 ** Find available bit in this ioa's resource map.
317 ** Use a "circular" search:
318 **   o Most IOVA's are "temporary" - avg search time should be small.
319 ** o keep a history of what happened for debugging
320 ** o KISS.
321 **
322 ** Perf optimizations:
323 ** o search for log2(size) bits at a time.
324 ** o search for available resource bits using byte/word/whatever.
325 ** o use different search for "large" (eg > 4 pages) or "very large"
326 **   (eg > 16 pages) mappings.
327 */
328 
329 /**
330  * ccio_alloc_range - Allocate pages in the ioc's resource map.
331  * @ioc: The I/O Controller.
332  * @pages_needed: The requested number of pages to be mapped into the
333  * I/O Pdir...
334  *
335  * This function searches the resource map of the ioc to locate a range
336  * of available pages for the requested size.
337  */
338 static int
339 ccio_alloc_range(struct ioc *ioc, struct device *dev, size_t size)
340 {
341 	unsigned int pages_needed = size >> IOVP_SHIFT;
342 	unsigned int res_idx;
343 	unsigned long boundary_size;
344 #ifdef CCIO_COLLECT_STATS
345 	unsigned long cr_start = mfctl(16);
346 #endif
347 
348 	BUG_ON(pages_needed == 0);
349 	BUG_ON((pages_needed * IOVP_SIZE) > DMA_CHUNK_SIZE);
350 
351 	DBG_RES("%s() size: %d pages_needed %d\n",
352 		__func__, size, pages_needed);
353 
354 	/*
355 	** "seek and ye shall find"...praying never hurts either...
356 	** ggg sacrifices another 710 to the computer gods.
357 	*/
358 
359 	boundary_size = ALIGN((unsigned long long)dma_get_seg_boundary(dev) + 1,
360 			      1ULL << IOVP_SHIFT) >> IOVP_SHIFT;
361 
362 	if (pages_needed <= 8) {
363 		/*
364 		 * LAN traffic will not thrash the TLB IFF the same NIC
365 		 * uses 8 adjacent pages to map separate payload data.
366 		 * ie the same byte in the resource bit map.
367 		 */
368 #if 0
369 		/* FIXME: bit search should shift it's way through
370 		 * an unsigned long - not byte at a time. As it is now,
371 		 * we effectively allocate this byte to this mapping.
372 		 */
373 		unsigned long mask = ~(~0UL >> pages_needed);
374 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, mask, 8);
375 #else
376 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xff, 8);
377 #endif
378 	} else if (pages_needed <= 16) {
379 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xffff, 16);
380 	} else if (pages_needed <= 32) {
381 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~(unsigned int)0, 32);
382 #ifdef __LP64__
383 	} else if (pages_needed <= 64) {
384 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~0UL, 64);
385 #endif
386 	} else {
387 		panic("%s: %s() Too many pages to map. pages_needed: %u\n",
388 		       __FILE__,  __func__, pages_needed);
389 	}
390 
391 	panic("%s: %s() I/O MMU is out of mapping resources.\n", __FILE__,
392 	      __func__);
393 
394 resource_found:
395 
396 	DBG_RES("%s() res_idx %d res_hint: %d\n",
397 		__func__, res_idx, ioc->res_hint);
398 
399 #ifdef CCIO_COLLECT_STATS
400 	{
401 		unsigned long cr_end = mfctl(16);
402 		unsigned long tmp = cr_end - cr_start;
403 		/* check for roll over */
404 		cr_start = (cr_end < cr_start) ?  -(tmp) : (tmp);
405 	}
406 	ioc->avg_search[ioc->avg_idx++] = cr_start;
407 	ioc->avg_idx &= CCIO_SEARCH_SAMPLE - 1;
408 	ioc->used_pages += pages_needed;
409 #endif
410 	/*
411 	** return the bit address.
412 	*/
413 	return res_idx << 3;
414 }
415 
416 #define CCIO_FREE_MAPPINGS(ioc, res_idx, mask, size) \
417         u##size *res_ptr = (u##size *)&((ioc)->res_map[res_idx]); \
418         BUG_ON((*res_ptr & mask) != mask); \
419         *res_ptr &= ~(mask);
420 
421 /**
422  * ccio_free_range - Free pages from the ioc's resource map.
423  * @ioc: The I/O Controller.
424  * @iova: The I/O Virtual Address.
425  * @pages_mapped: The requested number of pages to be freed from the
426  * I/O Pdir.
427  *
428  * This function frees the resouces allocated for the iova.
429  */
430 static void
431 ccio_free_range(struct ioc *ioc, dma_addr_t iova, unsigned long pages_mapped)
432 {
433 	unsigned long iovp = CCIO_IOVP(iova);
434 	unsigned int res_idx = PDIR_INDEX(iovp) >> 3;
435 
436 	BUG_ON(pages_mapped == 0);
437 	BUG_ON((pages_mapped * IOVP_SIZE) > DMA_CHUNK_SIZE);
438 	BUG_ON(pages_mapped > BITS_PER_LONG);
439 
440 	DBG_RES("%s():  res_idx: %d pages_mapped %d\n",
441 		__func__, res_idx, pages_mapped);
442 
443 #ifdef CCIO_COLLECT_STATS
444 	ioc->used_pages -= pages_mapped;
445 #endif
446 
447 	if(pages_mapped <= 8) {
448 #if 0
449 		/* see matching comments in alloc_range */
450 		unsigned long mask = ~(~0UL >> pages_mapped);
451 		CCIO_FREE_MAPPINGS(ioc, res_idx, mask, 8);
452 #else
453 		CCIO_FREE_MAPPINGS(ioc, res_idx, 0xffUL, 8);
454 #endif
455 	} else if(pages_mapped <= 16) {
456 		CCIO_FREE_MAPPINGS(ioc, res_idx, 0xffffUL, 16);
457 	} else if(pages_mapped <= 32) {
458 		CCIO_FREE_MAPPINGS(ioc, res_idx, ~(unsigned int)0, 32);
459 #ifdef __LP64__
460 	} else if(pages_mapped <= 64) {
461 		CCIO_FREE_MAPPINGS(ioc, res_idx, ~0UL, 64);
462 #endif
463 	} else {
464 		panic("%s:%s() Too many pages to unmap.\n", __FILE__,
465 		      __func__);
466 	}
467 }
468 
469 /****************************************************************
470 **
471 **          CCIO dma_ops support routines
472 **
473 *****************************************************************/
474 
475 typedef unsigned long space_t;
476 #define KERNEL_SPACE 0
477 
478 /*
479 ** DMA "Page Type" and Hints
480 ** o if SAFE_DMA isn't set, mapping is for FAST_DMA. SAFE_DMA should be
481 **   set for subcacheline DMA transfers since we don't want to damage the
482 **   other part of a cacheline.
483 ** o SAFE_DMA must be set for "memory" allocated via pci_alloc_consistent().
484 **   This bit tells U2 to do R/M/W for partial cachelines. "Streaming"
485 **   data can avoid this if the mapping covers full cache lines.
486 ** o STOP_MOST is needed for atomicity across cachelines.
487 **   Apparently only "some EISA devices" need this.
488 **   Using CONFIG_ISA is hack. Only the IOA with EISA under it needs
489 **   to use this hint iff the EISA devices needs this feature.
490 **   According to the U2 ERS, STOP_MOST enabled pages hurt performance.
491 ** o PREFETCH should *not* be set for cases like Multiple PCI devices
492 **   behind GSCtoPCI (dino) bus converter. Only one cacheline per GSC
493 **   device can be fetched and multiply DMA streams will thrash the
494 **   prefetch buffer and burn memory bandwidth. See 6.7.3 "Prefetch Rules
495 **   and Invalidation of Prefetch Entries".
496 **
497 ** FIXME: the default hints need to be per GSC device - not global.
498 **
499 ** HP-UX dorks: linux device driver programming model is totally different
500 **    than HP-UX's. HP-UX always sets HINT_PREFETCH since it's drivers
501 **    do special things to work on non-coherent platforms...linux has to
502 **    be much more careful with this.
503 */
504 #define IOPDIR_VALID    0x01UL
505 #define HINT_SAFE_DMA   0x02UL	/* used for pci_alloc_consistent() pages */
506 #ifdef CONFIG_EISA
507 #define HINT_STOP_MOST  0x04UL	/* LSL support */
508 #else
509 #define HINT_STOP_MOST  0x00UL	/* only needed for "some EISA devices" */
510 #endif
511 #define HINT_UDPATE_ENB 0x08UL  /* not used/supported by U2 */
512 #define HINT_PREFETCH   0x10UL	/* for outbound pages which are not SAFE */
513 
514 
515 /*
516 ** Use direction (ie PCI_DMA_TODEVICE) to pick hint.
517 ** ccio_alloc_consistent() depends on this to get SAFE_DMA
518 ** when it passes in BIDIRECTIONAL flag.
519 */
520 static u32 hint_lookup[] = {
521 	[PCI_DMA_BIDIRECTIONAL]	= HINT_STOP_MOST | HINT_SAFE_DMA | IOPDIR_VALID,
522 	[PCI_DMA_TODEVICE]	= HINT_STOP_MOST | HINT_PREFETCH | IOPDIR_VALID,
523 	[PCI_DMA_FROMDEVICE]	= HINT_STOP_MOST | IOPDIR_VALID,
524 };
525 
526 /**
527  * ccio_io_pdir_entry - Initialize an I/O Pdir.
528  * @pdir_ptr: A pointer into I/O Pdir.
529  * @sid: The Space Identifier.
530  * @vba: The virtual address.
531  * @hints: The DMA Hint.
532  *
533  * Given a virtual address (vba, arg2) and space id, (sid, arg1),
534  * load the I/O PDIR entry pointed to by pdir_ptr (arg0). Each IO Pdir
535  * entry consists of 8 bytes as shown below (MSB == bit 0):
536  *
537  *
538  * WORD 0:
539  * +------+----------------+-----------------------------------------------+
540  * | Phys | Virtual Index  |               Phys                            |
541  * | 0:3  |     0:11       |               4:19                            |
542  * |4 bits|   12 bits      |              16 bits                          |
543  * +------+----------------+-----------------------------------------------+
544  * WORD 1:
545  * +-----------------------+-----------------------------------------------+
546  * |      Phys    |  Rsvd  | Prefetch |Update |Rsvd  |Lock  |Safe  |Valid  |
547  * |     20:39    |        | Enable   |Enable |      |Enable|DMA   |       |
548  * |    20 bits   | 5 bits | 1 bit    |1 bit  |2 bits|1 bit |1 bit |1 bit  |
549  * +-----------------------+-----------------------------------------------+
550  *
551  * The virtual index field is filled with the results of the LCI
552  * (Load Coherence Index) instruction.  The 8 bits used for the virtual
553  * index are bits 12:19 of the value returned by LCI.
554  */
555 static void CCIO_INLINE
556 ccio_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
557 		   unsigned long hints)
558 {
559 	register unsigned long pa;
560 	register unsigned long ci; /* coherent index */
561 
562 	/* We currently only support kernel addresses */
563 	BUG_ON(sid != KERNEL_SPACE);
564 
565 	mtsp(sid,1);
566 
567 	/*
568 	** WORD 1 - low order word
569 	** "hints" parm includes the VALID bit!
570 	** "dep" clobbers the physical address offset bits as well.
571 	*/
572 	pa = virt_to_phys(vba);
573 	asm volatile("depw  %1,31,12,%0" : "+r" (pa) : "r" (hints));
574 	((u32 *)pdir_ptr)[1] = (u32) pa;
575 
576 	/*
577 	** WORD 0 - high order word
578 	*/
579 
580 #ifdef __LP64__
581 	/*
582 	** get bits 12:15 of physical address
583 	** shift bits 16:31 of physical address
584 	** and deposit them
585 	*/
586 	asm volatile ("extrd,u %1,15,4,%0" : "=r" (ci) : "r" (pa));
587 	asm volatile ("extrd,u %1,31,16,%0" : "+r" (pa) : "r" (pa));
588 	asm volatile ("depd  %1,35,4,%0" : "+r" (pa) : "r" (ci));
589 #else
590 	pa = 0;
591 #endif
592 	/*
593 	** get CPU coherency index bits
594 	** Grab virtual index [0:11]
595 	** Deposit virt_idx bits into I/O PDIR word
596 	*/
597 	asm volatile ("lci %%r0(%%sr1, %1), %0" : "=r" (ci) : "r" (vba));
598 	asm volatile ("extru %1,19,12,%0" : "+r" (ci) : "r" (ci));
599 	asm volatile ("depw  %1,15,12,%0" : "+r" (pa) : "r" (ci));
600 
601 	((u32 *)pdir_ptr)[0] = (u32) pa;
602 
603 
604 	/* FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
605 	**        PCX-U/U+ do. (eg C200/C240)
606 	**        PCX-T'? Don't know. (eg C110 or similar K-class)
607 	**
608 	** See PDC_MODEL/option 0/SW_CAP word for "Non-coherent IO-PDIR bit".
609 	**
610 	** "Since PCX-U employs an offset hash that is incompatible with
611 	** the real mode coherence index generation of U2, the PDIR entry
612 	** must be flushed to memory to retain coherence."
613 	*/
614 	asm_io_fdc(pdir_ptr);
615 	asm_io_sync();
616 }
617 
618 /**
619  * ccio_clear_io_tlb - Remove stale entries from the I/O TLB.
620  * @ioc: The I/O Controller.
621  * @iovp: The I/O Virtual Page.
622  * @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
623  *
624  * Purge invalid I/O PDIR entries from the I/O TLB.
625  *
626  * FIXME: Can we change the byte_cnt to pages_mapped?
627  */
628 static CCIO_INLINE void
629 ccio_clear_io_tlb(struct ioc *ioc, dma_addr_t iovp, size_t byte_cnt)
630 {
631 	u32 chain_size = 1 << ioc->chainid_shift;
632 
633 	iovp &= IOVP_MASK;	/* clear offset bits, just want pagenum */
634 	byte_cnt += chain_size;
635 
636 	while(byte_cnt > chain_size) {
637 		WRITE_U32(CMD_TLB_PURGE | iovp, &ioc->ioc_regs->io_command);
638 		iovp += chain_size;
639 		byte_cnt -= chain_size;
640 	}
641 }
642 
643 /**
644  * ccio_mark_invalid - Mark the I/O Pdir entries invalid.
645  * @ioc: The I/O Controller.
646  * @iova: The I/O Virtual Address.
647  * @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
648  *
649  * Mark the I/O Pdir entries invalid and blow away the corresponding I/O
650  * TLB entries.
651  *
652  * FIXME: at some threshold it might be "cheaper" to just blow
653  *        away the entire I/O TLB instead of individual entries.
654  *
655  * FIXME: Uturn has 256 TLB entries. We don't need to purge every
656  *        PDIR entry - just once for each possible TLB entry.
657  *        (We do need to maker I/O PDIR entries invalid regardless).
658  *
659  * FIXME: Can we change byte_cnt to pages_mapped?
660  */
661 static CCIO_INLINE void
662 ccio_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
663 {
664 	u32 iovp = (u32)CCIO_IOVP(iova);
665 	size_t saved_byte_cnt;
666 
667 	/* round up to nearest page size */
668 	saved_byte_cnt = byte_cnt = ALIGN(byte_cnt, IOVP_SIZE);
669 
670 	while(byte_cnt > 0) {
671 		/* invalidate one page at a time */
672 		unsigned int idx = PDIR_INDEX(iovp);
673 		char *pdir_ptr = (char *) &(ioc->pdir_base[idx]);
674 
675 		BUG_ON(idx >= (ioc->pdir_size / sizeof(u64)));
676 		pdir_ptr[7] = 0;	/* clear only VALID bit */
677 		/*
678 		** FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
679 		**   PCX-U/U+ do. (eg C200/C240)
680 		** See PDC_MODEL/option 0/SW_CAP for "Non-coherent IO-PDIR bit".
681 		*/
682 		asm_io_fdc(pdir_ptr);
683 
684 		iovp     += IOVP_SIZE;
685 		byte_cnt -= IOVP_SIZE;
686 	}
687 
688 	asm_io_sync();
689 	ccio_clear_io_tlb(ioc, CCIO_IOVP(iova), saved_byte_cnt);
690 }
691 
692 /****************************************************************
693 **
694 **          CCIO dma_ops
695 **
696 *****************************************************************/
697 
698 /**
699  * ccio_dma_supported - Verify the IOMMU supports the DMA address range.
700  * @dev: The PCI device.
701  * @mask: A bit mask describing the DMA address range of the device.
702  */
703 static int
704 ccio_dma_supported(struct device *dev, u64 mask)
705 {
706 	if(dev == NULL) {
707 		printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
708 		BUG();
709 		return 0;
710 	}
711 
712 	/* only support 32-bit or better devices (ie PCI/GSC) */
713 	return (int)(mask >= 0xffffffffUL);
714 }
715 
716 /**
717  * ccio_map_single - Map an address range into the IOMMU.
718  * @dev: The PCI device.
719  * @addr: The start address of the DMA region.
720  * @size: The length of the DMA region.
721  * @direction: The direction of the DMA transaction (to/from device).
722  *
723  * This function implements the pci_map_single function.
724  */
725 static dma_addr_t
726 ccio_map_single(struct device *dev, void *addr, size_t size,
727 		enum dma_data_direction direction)
728 {
729 	int idx;
730 	struct ioc *ioc;
731 	unsigned long flags;
732 	dma_addr_t iovp;
733 	dma_addr_t offset;
734 	u64 *pdir_start;
735 	unsigned long hint = hint_lookup[(int)direction];
736 
737 	BUG_ON(!dev);
738 	ioc = GET_IOC(dev);
739 	if (!ioc)
740 		return DMA_MAPPING_ERROR;
741 
742 	BUG_ON(size <= 0);
743 
744 	/* save offset bits */
745 	offset = ((unsigned long) addr) & ~IOVP_MASK;
746 
747 	/* round up to nearest IOVP_SIZE */
748 	size = ALIGN(size + offset, IOVP_SIZE);
749 	spin_lock_irqsave(&ioc->res_lock, flags);
750 
751 #ifdef CCIO_COLLECT_STATS
752 	ioc->msingle_calls++;
753 	ioc->msingle_pages += size >> IOVP_SHIFT;
754 #endif
755 
756 	idx = ccio_alloc_range(ioc, dev, size);
757 	iovp = (dma_addr_t)MKIOVP(idx);
758 
759 	pdir_start = &(ioc->pdir_base[idx]);
760 
761 	DBG_RUN("%s() 0x%p -> 0x%lx size: %0x%x\n",
762 		__func__, addr, (long)iovp | offset, size);
763 
764 	/* If not cacheline aligned, force SAFE_DMA on the whole mess */
765 	if((size % L1_CACHE_BYTES) || ((unsigned long)addr % L1_CACHE_BYTES))
766 		hint |= HINT_SAFE_DMA;
767 
768 	while(size > 0) {
769 		ccio_io_pdir_entry(pdir_start, KERNEL_SPACE, (unsigned long)addr, hint);
770 
771 		DBG_RUN(" pdir %p %08x%08x\n",
772 			pdir_start,
773 			(u32) (((u32 *) pdir_start)[0]),
774 			(u32) (((u32 *) pdir_start)[1]));
775 		++pdir_start;
776 		addr += IOVP_SIZE;
777 		size -= IOVP_SIZE;
778 	}
779 
780 	spin_unlock_irqrestore(&ioc->res_lock, flags);
781 
782 	/* form complete address */
783 	return CCIO_IOVA(iovp, offset);
784 }
785 
786 
787 static dma_addr_t
788 ccio_map_page(struct device *dev, struct page *page, unsigned long offset,
789 		size_t size, enum dma_data_direction direction,
790 		unsigned long attrs)
791 {
792 	return ccio_map_single(dev, page_address(page) + offset, size,
793 			direction);
794 }
795 
796 
797 /**
798  * ccio_unmap_page - Unmap an address range from the IOMMU.
799  * @dev: The PCI device.
800  * @addr: The start address of the DMA region.
801  * @size: The length of the DMA region.
802  * @direction: The direction of the DMA transaction (to/from device).
803  */
804 static void
805 ccio_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
806 		enum dma_data_direction direction, unsigned long attrs)
807 {
808 	struct ioc *ioc;
809 	unsigned long flags;
810 	dma_addr_t offset = iova & ~IOVP_MASK;
811 
812 	BUG_ON(!dev);
813 	ioc = GET_IOC(dev);
814 	if (!ioc) {
815 		WARN_ON(!ioc);
816 		return;
817 	}
818 
819 	DBG_RUN("%s() iovp 0x%lx/%x\n",
820 		__func__, (long)iova, size);
821 
822 	iova ^= offset;        /* clear offset bits */
823 	size += offset;
824 	size = ALIGN(size, IOVP_SIZE);
825 
826 	spin_lock_irqsave(&ioc->res_lock, flags);
827 
828 #ifdef CCIO_COLLECT_STATS
829 	ioc->usingle_calls++;
830 	ioc->usingle_pages += size >> IOVP_SHIFT;
831 #endif
832 
833 	ccio_mark_invalid(ioc, iova, size);
834 	ccio_free_range(ioc, iova, (size >> IOVP_SHIFT));
835 	spin_unlock_irqrestore(&ioc->res_lock, flags);
836 }
837 
838 /**
839  * ccio_alloc - Allocate a consistent DMA mapping.
840  * @dev: The PCI device.
841  * @size: The length of the DMA region.
842  * @dma_handle: The DMA address handed back to the device (not the cpu).
843  *
844  * This function implements the pci_alloc_consistent function.
845  */
846 static void *
847 ccio_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag,
848 		unsigned long attrs)
849 {
850       void *ret;
851 #if 0
852 /* GRANT Need to establish hierarchy for non-PCI devs as well
853 ** and then provide matching gsc_map_xxx() functions for them as well.
854 */
855 	if(!hwdev) {
856 		/* only support PCI */
857 		*dma_handle = 0;
858 		return 0;
859 	}
860 #endif
861         ret = (void *) __get_free_pages(flag, get_order(size));
862 
863 	if (ret) {
864 		memset(ret, 0, size);
865 		*dma_handle = ccio_map_single(dev, ret, size, PCI_DMA_BIDIRECTIONAL);
866 	}
867 
868 	return ret;
869 }
870 
871 /**
872  * ccio_free - Free a consistent DMA mapping.
873  * @dev: The PCI device.
874  * @size: The length of the DMA region.
875  * @cpu_addr: The cpu address returned from the ccio_alloc_consistent.
876  * @dma_handle: The device address returned from the ccio_alloc_consistent.
877  *
878  * This function implements the pci_free_consistent function.
879  */
880 static void
881 ccio_free(struct device *dev, size_t size, void *cpu_addr,
882 		dma_addr_t dma_handle, unsigned long attrs)
883 {
884 	ccio_unmap_page(dev, dma_handle, size, 0, 0);
885 	free_pages((unsigned long)cpu_addr, get_order(size));
886 }
887 
888 /*
889 ** Since 0 is a valid pdir_base index value, can't use that
890 ** to determine if a value is valid or not. Use a flag to indicate
891 ** the SG list entry contains a valid pdir index.
892 */
893 #define PIDE_FLAG 0x80000000UL
894 
895 #ifdef CCIO_COLLECT_STATS
896 #define IOMMU_MAP_STATS
897 #endif
898 #include "iommu-helpers.h"
899 
900 /**
901  * ccio_map_sg - Map the scatter/gather list into the IOMMU.
902  * @dev: The PCI device.
903  * @sglist: The scatter/gather list to be mapped in the IOMMU.
904  * @nents: The number of entries in the scatter/gather list.
905  * @direction: The direction of the DMA transaction (to/from device).
906  *
907  * This function implements the pci_map_sg function.
908  */
909 static int
910 ccio_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
911 	    enum dma_data_direction direction, unsigned long attrs)
912 {
913 	struct ioc *ioc;
914 	int coalesced, filled = 0;
915 	unsigned long flags;
916 	unsigned long hint = hint_lookup[(int)direction];
917 	unsigned long prev_len = 0, current_len = 0;
918 	int i;
919 
920 	BUG_ON(!dev);
921 	ioc = GET_IOC(dev);
922 	if (!ioc)
923 		return 0;
924 
925 	DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
926 
927 	/* Fast path single entry scatterlists. */
928 	if (nents == 1) {
929 		sg_dma_address(sglist) = ccio_map_single(dev,
930 				sg_virt(sglist), sglist->length,
931 				direction);
932 		sg_dma_len(sglist) = sglist->length;
933 		return 1;
934 	}
935 
936 	for(i = 0; i < nents; i++)
937 		prev_len += sglist[i].length;
938 
939 	spin_lock_irqsave(&ioc->res_lock, flags);
940 
941 #ifdef CCIO_COLLECT_STATS
942 	ioc->msg_calls++;
943 #endif
944 
945 	/*
946 	** First coalesce the chunks and allocate I/O pdir space
947 	**
948 	** If this is one DMA stream, we can properly map using the
949 	** correct virtual address associated with each DMA page.
950 	** w/o this association, we wouldn't have coherent DMA!
951 	** Access to the virtual address is what forces a two pass algorithm.
952 	*/
953 	coalesced = iommu_coalesce_chunks(ioc, dev, sglist, nents, ccio_alloc_range);
954 
955 	/*
956 	** Program the I/O Pdir
957 	**
958 	** map the virtual addresses to the I/O Pdir
959 	** o dma_address will contain the pdir index
960 	** o dma_len will contain the number of bytes to map
961 	** o page/offset contain the virtual address.
962 	*/
963 	filled = iommu_fill_pdir(ioc, sglist, nents, hint, ccio_io_pdir_entry);
964 
965 	spin_unlock_irqrestore(&ioc->res_lock, flags);
966 
967 	BUG_ON(coalesced != filled);
968 
969 	DBG_RUN_SG("%s() DONE %d mappings\n", __func__, filled);
970 
971 	for (i = 0; i < filled; i++)
972 		current_len += sg_dma_len(sglist + i);
973 
974 	BUG_ON(current_len != prev_len);
975 
976 	return filled;
977 }
978 
979 /**
980  * ccio_unmap_sg - Unmap the scatter/gather list from the IOMMU.
981  * @dev: The PCI device.
982  * @sglist: The scatter/gather list to be unmapped from the IOMMU.
983  * @nents: The number of entries in the scatter/gather list.
984  * @direction: The direction of the DMA transaction (to/from device).
985  *
986  * This function implements the pci_unmap_sg function.
987  */
988 static void
989 ccio_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
990 	      enum dma_data_direction direction, unsigned long attrs)
991 {
992 	struct ioc *ioc;
993 
994 	BUG_ON(!dev);
995 	ioc = GET_IOC(dev);
996 	if (!ioc) {
997 		WARN_ON(!ioc);
998 		return;
999 	}
1000 
1001 	DBG_RUN_SG("%s() START %d entries, %p,%x\n",
1002 		__func__, nents, sg_virt(sglist), sglist->length);
1003 
1004 #ifdef CCIO_COLLECT_STATS
1005 	ioc->usg_calls++;
1006 #endif
1007 
1008 	while(sg_dma_len(sglist) && nents--) {
1009 
1010 #ifdef CCIO_COLLECT_STATS
1011 		ioc->usg_pages += sg_dma_len(sglist) >> PAGE_SHIFT;
1012 #endif
1013 		ccio_unmap_page(dev, sg_dma_address(sglist),
1014 				  sg_dma_len(sglist), direction, 0);
1015 		++sglist;
1016 	}
1017 
1018 	DBG_RUN_SG("%s() DONE (nents %d)\n", __func__, nents);
1019 }
1020 
1021 static const struct dma_map_ops ccio_ops = {
1022 	.dma_supported =	ccio_dma_supported,
1023 	.alloc =		ccio_alloc,
1024 	.free =			ccio_free,
1025 	.map_page =		ccio_map_page,
1026 	.unmap_page =		ccio_unmap_page,
1027 	.map_sg = 		ccio_map_sg,
1028 	.unmap_sg = 		ccio_unmap_sg,
1029 };
1030 
1031 #ifdef CONFIG_PROC_FS
1032 static int ccio_proc_info(struct seq_file *m, void *p)
1033 {
1034 	struct ioc *ioc = ioc_list;
1035 
1036 	while (ioc != NULL) {
1037 		unsigned int total_pages = ioc->res_size << 3;
1038 #ifdef CCIO_COLLECT_STATS
1039 		unsigned long avg = 0, min, max;
1040 		int j;
1041 #endif
1042 
1043 		seq_printf(m, "%s\n", ioc->name);
1044 
1045 		seq_printf(m, "Cujo 2.0 bug    : %s\n",
1046 			   (ioc->cujo20_bug ? "yes" : "no"));
1047 
1048 		seq_printf(m, "IO PDIR size    : %d bytes (%d entries)\n",
1049 			   total_pages * 8, total_pages);
1050 
1051 #ifdef CCIO_COLLECT_STATS
1052 		seq_printf(m, "IO PDIR entries : %ld free  %ld used (%d%%)\n",
1053 			   total_pages - ioc->used_pages, ioc->used_pages,
1054 			   (int)(ioc->used_pages * 100 / total_pages));
1055 #endif
1056 
1057 		seq_printf(m, "Resource bitmap : %d bytes (%d pages)\n",
1058 			   ioc->res_size, total_pages);
1059 
1060 #ifdef CCIO_COLLECT_STATS
1061 		min = max = ioc->avg_search[0];
1062 		for(j = 0; j < CCIO_SEARCH_SAMPLE; ++j) {
1063 			avg += ioc->avg_search[j];
1064 			if(ioc->avg_search[j] > max)
1065 				max = ioc->avg_search[j];
1066 			if(ioc->avg_search[j] < min)
1067 				min = ioc->avg_search[j];
1068 		}
1069 		avg /= CCIO_SEARCH_SAMPLE;
1070 		seq_printf(m, "  Bitmap search : %ld/%ld/%ld (min/avg/max CPU Cycles)\n",
1071 			   min, avg, max);
1072 
1073 		seq_printf(m, "pci_map_single(): %8ld calls  %8ld pages (avg %d/1000)\n",
1074 			   ioc->msingle_calls, ioc->msingle_pages,
1075 			   (int)((ioc->msingle_pages * 1000)/ioc->msingle_calls));
1076 
1077 		/* KLUGE - unmap_sg calls unmap_page for each mapped page */
1078 		min = ioc->usingle_calls - ioc->usg_calls;
1079 		max = ioc->usingle_pages - ioc->usg_pages;
1080 		seq_printf(m, "pci_unmap_single: %8ld calls  %8ld pages (avg %d/1000)\n",
1081 			   min, max, (int)((max * 1000)/min));
1082 
1083 		seq_printf(m, "pci_map_sg()    : %8ld calls  %8ld pages (avg %d/1000)\n",
1084 			   ioc->msg_calls, ioc->msg_pages,
1085 			   (int)((ioc->msg_pages * 1000)/ioc->msg_calls));
1086 
1087 		seq_printf(m, "pci_unmap_sg()  : %8ld calls  %8ld pages (avg %d/1000)\n\n\n",
1088 			   ioc->usg_calls, ioc->usg_pages,
1089 			   (int)((ioc->usg_pages * 1000)/ioc->usg_calls));
1090 #endif	/* CCIO_COLLECT_STATS */
1091 
1092 		ioc = ioc->next;
1093 	}
1094 
1095 	return 0;
1096 }
1097 
1098 static int ccio_proc_bitmap_info(struct seq_file *m, void *p)
1099 {
1100 	struct ioc *ioc = ioc_list;
1101 
1102 	while (ioc != NULL) {
1103 		seq_hex_dump(m, "   ", DUMP_PREFIX_NONE, 32, 4, ioc->res_map,
1104 			     ioc->res_size, false);
1105 		seq_putc(m, '\n');
1106 		ioc = ioc->next;
1107 		break; /* XXX - remove me */
1108 	}
1109 
1110 	return 0;
1111 }
1112 #endif /* CONFIG_PROC_FS */
1113 
1114 /**
1115  * ccio_find_ioc - Find the ioc in the ioc_list
1116  * @hw_path: The hardware path of the ioc.
1117  *
1118  * This function searches the ioc_list for an ioc that matches
1119  * the provide hardware path.
1120  */
1121 static struct ioc * ccio_find_ioc(int hw_path)
1122 {
1123 	int i;
1124 	struct ioc *ioc;
1125 
1126 	ioc = ioc_list;
1127 	for (i = 0; i < ioc_count; i++) {
1128 		if (ioc->hw_path == hw_path)
1129 			return ioc;
1130 
1131 		ioc = ioc->next;
1132 	}
1133 
1134 	return NULL;
1135 }
1136 
1137 /**
1138  * ccio_get_iommu - Find the iommu which controls this device
1139  * @dev: The parisc device.
1140  *
1141  * This function searches through the registered IOMMU's and returns
1142  * the appropriate IOMMU for the device based on its hardware path.
1143  */
1144 void * ccio_get_iommu(const struct parisc_device *dev)
1145 {
1146 	dev = find_pa_parent_type(dev, HPHW_IOA);
1147 	if (!dev)
1148 		return NULL;
1149 
1150 	return ccio_find_ioc(dev->hw_path);
1151 }
1152 
1153 #define CUJO_20_STEP       0x10000000	/* inc upper nibble */
1154 
1155 /* Cujo 2.0 has a bug which will silently corrupt data being transferred
1156  * to/from certain pages.  To avoid this happening, we mark these pages
1157  * as `used', and ensure that nothing will try to allocate from them.
1158  */
1159 void __init ccio_cujo20_fixup(struct parisc_device *cujo, u32 iovp)
1160 {
1161 	unsigned int idx;
1162 	struct parisc_device *dev = parisc_parent(cujo);
1163 	struct ioc *ioc = ccio_get_iommu(dev);
1164 	u8 *res_ptr;
1165 
1166 	ioc->cujo20_bug = 1;
1167 	res_ptr = ioc->res_map;
1168 	idx = PDIR_INDEX(iovp) >> 3;
1169 
1170 	while (idx < ioc->res_size) {
1171  		res_ptr[idx] |= 0xff;
1172 		idx += PDIR_INDEX(CUJO_20_STEP) >> 3;
1173 	}
1174 }
1175 
1176 #if 0
1177 /* GRANT -  is this needed for U2 or not? */
1178 
1179 /*
1180 ** Get the size of the I/O TLB for this I/O MMU.
1181 **
1182 ** If spa_shift is non-zero (ie probably U2),
1183 ** then calculate the I/O TLB size using spa_shift.
1184 **
1185 ** Otherwise we are supposed to get the IODC entry point ENTRY TLB
1186 ** and execute it. However, both U2 and Uturn firmware supplies spa_shift.
1187 ** I think only Java (K/D/R-class too?) systems don't do this.
1188 */
1189 static int
1190 ccio_get_iotlb_size(struct parisc_device *dev)
1191 {
1192 	if (dev->spa_shift == 0) {
1193 		panic("%s() : Can't determine I/O TLB size.\n", __func__);
1194 	}
1195 	return (1 << dev->spa_shift);
1196 }
1197 #else
1198 
1199 /* Uturn supports 256 TLB entries */
1200 #define CCIO_CHAINID_SHIFT	8
1201 #define CCIO_CHAINID_MASK	0xff
1202 #endif /* 0 */
1203 
1204 /* We *can't* support JAVA (T600). Venture there at your own risk. */
1205 static const struct parisc_device_id ccio_tbl[] __initconst = {
1206 	{ HPHW_IOA, HVERSION_REV_ANY_ID, U2_IOA_RUNWAY, 0xb }, /* U2 */
1207 	{ HPHW_IOA, HVERSION_REV_ANY_ID, UTURN_IOA_RUNWAY, 0xb }, /* UTurn */
1208 	{ 0, }
1209 };
1210 
1211 static int ccio_probe(struct parisc_device *dev);
1212 
1213 static struct parisc_driver ccio_driver __refdata = {
1214 	.name =		"ccio",
1215 	.id_table =	ccio_tbl,
1216 	.probe =	ccio_probe,
1217 };
1218 
1219 /**
1220  * ccio_ioc_init - Initialize the I/O Controller
1221  * @ioc: The I/O Controller.
1222  *
1223  * Initialize the I/O Controller which includes setting up the
1224  * I/O Page Directory, the resource map, and initalizing the
1225  * U2/Uturn chip into virtual mode.
1226  */
1227 static void __init
1228 ccio_ioc_init(struct ioc *ioc)
1229 {
1230 	int i;
1231 	unsigned int iov_order;
1232 	u32 iova_space_size;
1233 
1234 	/*
1235 	** Determine IOVA Space size from memory size.
1236 	**
1237 	** Ideally, PCI drivers would register the maximum number
1238 	** of DMA they can have outstanding for each device they
1239 	** own.  Next best thing would be to guess how much DMA
1240 	** can be outstanding based on PCI Class/sub-class. Both
1241 	** methods still require some "extra" to support PCI
1242 	** Hot-Plug/Removal of PCI cards. (aka PCI OLARD).
1243 	*/
1244 
1245 	iova_space_size = (u32) (totalram_pages() / count_parisc_driver(&ccio_driver));
1246 
1247 	/* limit IOVA space size to 1MB-1GB */
1248 
1249 	if (iova_space_size < (1 << (20 - PAGE_SHIFT))) {
1250 		iova_space_size =  1 << (20 - PAGE_SHIFT);
1251 #ifdef __LP64__
1252 	} else if (iova_space_size > (1 << (30 - PAGE_SHIFT))) {
1253 		iova_space_size =  1 << (30 - PAGE_SHIFT);
1254 #endif
1255 	}
1256 
1257 	/*
1258 	** iova space must be log2() in size.
1259 	** thus, pdir/res_map will also be log2().
1260 	*/
1261 
1262 	/* We could use larger page sizes in order to *decrease* the number
1263 	** of mappings needed.  (ie 8k pages means 1/2 the mappings).
1264 	**
1265 	** Note: Grant Grunder says "Using 8k I/O pages isn't trivial either
1266 	**   since the pages must also be physically contiguous - typically
1267 	**   this is the case under linux."
1268 	*/
1269 
1270 	iov_order = get_order(iova_space_size << PAGE_SHIFT);
1271 
1272 	/* iova_space_size is now bytes, not pages */
1273 	iova_space_size = 1 << (iov_order + PAGE_SHIFT);
1274 
1275 	ioc->pdir_size = (iova_space_size / IOVP_SIZE) * sizeof(u64);
1276 
1277 	BUG_ON(ioc->pdir_size > 8 * 1024 * 1024);   /* max pdir size <= 8MB */
1278 
1279 	/* Verify it's a power of two */
1280 	BUG_ON((1 << get_order(ioc->pdir_size)) != (ioc->pdir_size >> PAGE_SHIFT));
1281 
1282 	DBG_INIT("%s() hpa 0x%p mem %luMB IOV %dMB (%d bits)\n",
1283 			__func__, ioc->ioc_regs,
1284 			(unsigned long) totalram_pages() >> (20 - PAGE_SHIFT),
1285 			iova_space_size>>20,
1286 			iov_order + PAGE_SHIFT);
1287 
1288 	ioc->pdir_base = (u64 *)__get_free_pages(GFP_KERNEL,
1289 						 get_order(ioc->pdir_size));
1290 	if(NULL == ioc->pdir_base) {
1291 		panic("%s() could not allocate I/O Page Table\n", __func__);
1292 	}
1293 	memset(ioc->pdir_base, 0, ioc->pdir_size);
1294 
1295 	BUG_ON((((unsigned long)ioc->pdir_base) & PAGE_MASK) != (unsigned long)ioc->pdir_base);
1296 	DBG_INIT(" base %p\n", ioc->pdir_base);
1297 
1298 	/* resource map size dictated by pdir_size */
1299  	ioc->res_size = (ioc->pdir_size / sizeof(u64)) >> 3;
1300 	DBG_INIT("%s() res_size 0x%x\n", __func__, ioc->res_size);
1301 
1302 	ioc->res_map = (u8 *)__get_free_pages(GFP_KERNEL,
1303 					      get_order(ioc->res_size));
1304 	if(NULL == ioc->res_map) {
1305 		panic("%s() could not allocate resource map\n", __func__);
1306 	}
1307 	memset(ioc->res_map, 0, ioc->res_size);
1308 
1309 	/* Initialize the res_hint to 16 */
1310 	ioc->res_hint = 16;
1311 
1312 	/* Initialize the spinlock */
1313 	spin_lock_init(&ioc->res_lock);
1314 
1315 	/*
1316 	** Chainid is the upper most bits of an IOVP used to determine
1317 	** which TLB entry an IOVP will use.
1318 	*/
1319 	ioc->chainid_shift = get_order(iova_space_size) + PAGE_SHIFT - CCIO_CHAINID_SHIFT;
1320 	DBG_INIT(" chainid_shift 0x%x\n", ioc->chainid_shift);
1321 
1322 	/*
1323 	** Initialize IOA hardware
1324 	*/
1325 	WRITE_U32(CCIO_CHAINID_MASK << ioc->chainid_shift,
1326 		  &ioc->ioc_regs->io_chain_id_mask);
1327 
1328 	WRITE_U32(virt_to_phys(ioc->pdir_base),
1329 		  &ioc->ioc_regs->io_pdir_base);
1330 
1331 	/*
1332 	** Go to "Virtual Mode"
1333 	*/
1334 	WRITE_U32(IOA_NORMAL_MODE, &ioc->ioc_regs->io_control);
1335 
1336 	/*
1337 	** Initialize all I/O TLB entries to 0 (Valid bit off).
1338 	*/
1339 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_m);
1340 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_l);
1341 
1342 	for(i = 1 << CCIO_CHAINID_SHIFT; i ; i--) {
1343 		WRITE_U32((CMD_TLB_DIRECT_WRITE | (i << ioc->chainid_shift)),
1344 			  &ioc->ioc_regs->io_command);
1345 	}
1346 }
1347 
1348 static void __init
1349 ccio_init_resource(struct resource *res, char *name, void __iomem *ioaddr)
1350 {
1351 	int result;
1352 
1353 	res->parent = NULL;
1354 	res->flags = IORESOURCE_MEM;
1355 	/*
1356 	 * bracing ((signed) ...) are required for 64bit kernel because
1357 	 * we only want to sign extend the lower 16 bits of the register.
1358 	 * The upper 16-bits of range registers are hardcoded to 0xffff.
1359 	 */
1360 	res->start = (unsigned long)((signed) READ_U32(ioaddr) << 16);
1361 	res->end = (unsigned long)((signed) (READ_U32(ioaddr + 4) << 16) - 1);
1362 	res->name = name;
1363 	/*
1364 	 * Check if this MMIO range is disable
1365 	 */
1366 	if (res->end + 1 == res->start)
1367 		return;
1368 
1369 	/* On some platforms (e.g. K-Class), we have already registered
1370 	 * resources for devices reported by firmware. Some are children
1371 	 * of ccio.
1372 	 * "insert" ccio ranges in the mmio hierarchy (/proc/iomem).
1373 	 */
1374 	result = insert_resource(&iomem_resource, res);
1375 	if (result < 0) {
1376 		printk(KERN_ERR "%s() failed to claim CCIO bus address space (%08lx,%08lx)\n",
1377 			__func__, (unsigned long)res->start, (unsigned long)res->end);
1378 	}
1379 }
1380 
1381 static void __init ccio_init_resources(struct ioc *ioc)
1382 {
1383 	struct resource *res = ioc->mmio_region;
1384 	char *name = kmalloc(14, GFP_KERNEL);
1385 
1386 	snprintf(name, 14, "GSC Bus [%d/]", ioc->hw_path);
1387 
1388 	ccio_init_resource(res, name, &ioc->ioc_regs->io_io_low);
1389 	ccio_init_resource(res + 1, name, &ioc->ioc_regs->io_io_low_hv);
1390 }
1391 
1392 static int new_ioc_area(struct resource *res, unsigned long size,
1393 		unsigned long min, unsigned long max, unsigned long align)
1394 {
1395 	if (max <= min)
1396 		return -EBUSY;
1397 
1398 	res->start = (max - size + 1) &~ (align - 1);
1399 	res->end = res->start + size;
1400 
1401 	/* We might be trying to expand the MMIO range to include
1402 	 * a child device that has already registered it's MMIO space.
1403 	 * Use "insert" instead of request_resource().
1404 	 */
1405 	if (!insert_resource(&iomem_resource, res))
1406 		return 0;
1407 
1408 	return new_ioc_area(res, size, min, max - size, align);
1409 }
1410 
1411 static int expand_ioc_area(struct resource *res, unsigned long size,
1412 		unsigned long min, unsigned long max, unsigned long align)
1413 {
1414 	unsigned long start, len;
1415 
1416 	if (!res->parent)
1417 		return new_ioc_area(res, size, min, max, align);
1418 
1419 	start = (res->start - size) &~ (align - 1);
1420 	len = res->end - start + 1;
1421 	if (start >= min) {
1422 		if (!adjust_resource(res, start, len))
1423 			return 0;
1424 	}
1425 
1426 	start = res->start;
1427 	len = ((size + res->end + align) &~ (align - 1)) - start;
1428 	if (start + len <= max) {
1429 		if (!adjust_resource(res, start, len))
1430 			return 0;
1431 	}
1432 
1433 	return -EBUSY;
1434 }
1435 
1436 /*
1437  * Dino calls this function.  Beware that we may get called on systems
1438  * which have no IOC (725, B180, C160L, etc) but do have a Dino.
1439  * So it's legal to find no parent IOC.
1440  *
1441  * Some other issues: one of the resources in the ioc may be unassigned.
1442  */
1443 int ccio_allocate_resource(const struct parisc_device *dev,
1444 		struct resource *res, unsigned long size,
1445 		unsigned long min, unsigned long max, unsigned long align)
1446 {
1447 	struct resource *parent = &iomem_resource;
1448 	struct ioc *ioc = ccio_get_iommu(dev);
1449 	if (!ioc)
1450 		goto out;
1451 
1452 	parent = ioc->mmio_region;
1453 	if (parent->parent &&
1454 	    !allocate_resource(parent, res, size, min, max, align, NULL, NULL))
1455 		return 0;
1456 
1457 	if ((parent + 1)->parent &&
1458 	    !allocate_resource(parent + 1, res, size, min, max, align,
1459 				NULL, NULL))
1460 		return 0;
1461 
1462 	if (!expand_ioc_area(parent, size, min, max, align)) {
1463 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1464 			     &ioc->ioc_regs->io_io_low);
1465 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1466 			     &ioc->ioc_regs->io_io_high);
1467 	} else if (!expand_ioc_area(parent + 1, size, min, max, align)) {
1468 		parent++;
1469 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1470 			     &ioc->ioc_regs->io_io_low_hv);
1471 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1472 			     &ioc->ioc_regs->io_io_high_hv);
1473 	} else {
1474 		return -EBUSY;
1475 	}
1476 
1477  out:
1478 	return allocate_resource(parent, res, size, min, max, align, NULL,NULL);
1479 }
1480 
1481 int ccio_request_resource(const struct parisc_device *dev,
1482 		struct resource *res)
1483 {
1484 	struct resource *parent;
1485 	struct ioc *ioc = ccio_get_iommu(dev);
1486 
1487 	if (!ioc) {
1488 		parent = &iomem_resource;
1489 	} else if ((ioc->mmio_region->start <= res->start) &&
1490 			(res->end <= ioc->mmio_region->end)) {
1491 		parent = ioc->mmio_region;
1492 	} else if (((ioc->mmio_region + 1)->start <= res->start) &&
1493 			(res->end <= (ioc->mmio_region + 1)->end)) {
1494 		parent = ioc->mmio_region + 1;
1495 	} else {
1496 		return -EBUSY;
1497 	}
1498 
1499 	/* "transparent" bus bridges need to register MMIO resources
1500 	 * firmware assigned them. e.g. children of hppb.c (e.g. K-class)
1501 	 * registered their resources in the PDC "bus walk" (See
1502 	 * arch/parisc/kernel/inventory.c).
1503 	 */
1504 	return insert_resource(parent, res);
1505 }
1506 
1507 /**
1508  * ccio_probe - Determine if ccio should claim this device.
1509  * @dev: The device which has been found
1510  *
1511  * Determine if ccio should claim this chip (return 0) or not (return 1).
1512  * If so, initialize the chip and tell other partners in crime they
1513  * have work to do.
1514  */
1515 static int __init ccio_probe(struct parisc_device *dev)
1516 {
1517 	int i;
1518 	struct ioc *ioc, **ioc_p = &ioc_list;
1519 	struct pci_hba_data *hba;
1520 
1521 	ioc = kzalloc(sizeof(struct ioc), GFP_KERNEL);
1522 	if (ioc == NULL) {
1523 		printk(KERN_ERR MODULE_NAME ": memory allocation failure\n");
1524 		return -ENOMEM;
1525 	}
1526 
1527 	ioc->name = dev->id.hversion == U2_IOA_RUNWAY ? "U2" : "UTurn";
1528 
1529 	printk(KERN_INFO "Found %s at 0x%lx\n", ioc->name,
1530 		(unsigned long)dev->hpa.start);
1531 
1532 	for (i = 0; i < ioc_count; i++) {
1533 		ioc_p = &(*ioc_p)->next;
1534 	}
1535 	*ioc_p = ioc;
1536 
1537 	ioc->hw_path = dev->hw_path;
1538 	ioc->ioc_regs = ioremap_nocache(dev->hpa.start, 4096);
1539 	if (!ioc->ioc_regs) {
1540 		kfree(ioc);
1541 		return -ENOMEM;
1542 	}
1543 	ccio_ioc_init(ioc);
1544 	ccio_init_resources(ioc);
1545 	hppa_dma_ops = &ccio_ops;
1546 
1547 	hba = kzalloc(sizeof(*hba), GFP_KERNEL);
1548 	/* if this fails, no I/O cards will work, so may as well bug */
1549 	BUG_ON(hba == NULL);
1550 
1551 	hba->iommu = ioc;
1552 	dev->dev.platform_data = hba;
1553 
1554 #ifdef CONFIG_PROC_FS
1555 	if (ioc_count == 0) {
1556 		proc_create_single(MODULE_NAME, 0, proc_runway_root,
1557 				ccio_proc_info);
1558 		proc_create_single(MODULE_NAME"-bitmap", 0, proc_runway_root,
1559 				ccio_proc_bitmap_info);
1560 	}
1561 #endif
1562 	ioc_count++;
1563 	return 0;
1564 }
1565 
1566 /**
1567  * ccio_init - ccio initialization procedure.
1568  *
1569  * Register this driver.
1570  */
1571 void __init ccio_init(void)
1572 {
1573 	register_parisc_driver(&ccio_driver);
1574 }
1575 
1576