xref: /linux/drivers/parisc/ccio-dma.c (revision 460ea8980511c01c1551012b9a6ec6a06d02da59)
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/dma-map-ops.h>
43 #include <linux/scatterlist.h>
44 #include <linux/iommu-helper.h>
45 #include <linux/export.h>
46 
47 #include <asm/byteorder.h>
48 #include <asm/cache.h>		/* for L1_CACHE_BYTES */
49 #include <linux/uaccess.h>
50 #include <asm/page.h>
51 #include <asm/dma.h>
52 #include <asm/io.h>
53 #include <asm/hardware.h>       /* for register_module() */
54 #include <asm/parisc-device.h>
55 
56 #include "iommu.h"
57 
58 /*
59 ** Choose "ccio" since that's what HP-UX calls it.
60 ** Make it easier for folks to migrate from one to the other :^)
61 */
62 #define MODULE_NAME "ccio"
63 
64 #undef DEBUG_CCIO_RES
65 #undef DEBUG_CCIO_RUN
66 #undef DEBUG_CCIO_INIT
67 #undef DEBUG_CCIO_RUN_SG
68 
69 #ifdef CONFIG_PROC_FS
70 /* depends on proc fs support. But costs CPU performance. */
71 #undef CCIO_COLLECT_STATS
72 #endif
73 
74 #include <asm/runway.h>		/* for proc_runway_root */
75 
76 #ifdef DEBUG_CCIO_INIT
77 #define DBG_INIT(x...)  printk(x)
78 #else
79 #define DBG_INIT(x...)
80 #endif
81 
82 #ifdef DEBUG_CCIO_RUN
83 #define DBG_RUN(x...)   printk(x)
84 #else
85 #define DBG_RUN(x...)
86 #endif
87 
88 #ifdef DEBUG_CCIO_RES
89 #define DBG_RES(x...)   printk(x)
90 #else
91 #define DBG_RES(x...)
92 #endif
93 
94 #ifdef DEBUG_CCIO_RUN_SG
95 #define DBG_RUN_SG(x...) printk(x)
96 #else
97 #define DBG_RUN_SG(x...)
98 #endif
99 
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 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  * @dev: The PCI device.
333  * @size: The requested number of bytes to be mapped into the
334  * I/O Pdir...
335  *
336  * This function searches the resource map of the ioc to locate a range
337  * of available pages for the requested size.
338  */
339 static int
340 ccio_alloc_range(struct ioc *ioc, struct device *dev, size_t size)
341 {
342 	unsigned int pages_needed = size >> IOVP_SHIFT;
343 	unsigned int res_idx;
344 	unsigned long boundary_size;
345 #ifdef CCIO_COLLECT_STATS
346 	unsigned long cr_start = mfctl(16);
347 #endif
348 
349 	BUG_ON(pages_needed == 0);
350 	BUG_ON((pages_needed * IOVP_SIZE) > DMA_CHUNK_SIZE);
351 
352 	DBG_RES("%s() size: %d pages_needed %d\n",
353 			__func__, size, pages_needed);
354 
355 	/*
356 	** "seek and ye shall find"...praying never hurts either...
357 	** ggg sacrifices another 710 to the computer gods.
358 	*/
359 
360 	boundary_size = dma_get_seg_boundary_nr_pages(dev, 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 	[DMA_BIDIRECTIONAL]	= HINT_STOP_MOST | HINT_SAFE_DMA | IOPDIR_VALID,
522 	[DMA_TO_DEVICE]		= HINT_STOP_MOST | HINT_PREFETCH | IOPDIR_VALID,
523 	[DMA_FROM_DEVICE]	= 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
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 	/*
566 	** WORD 1 - low order word
567 	** "hints" parm includes the VALID bit!
568 	** "dep" clobbers the physical address offset bits as well.
569 	*/
570 	pa = lpa(vba);
571 	asm volatile("depw  %1,31,12,%0" : "+r" (pa) : "r" (hints));
572 	((u32 *)pdir_ptr)[1] = (u32) pa;
573 
574 	/*
575 	** WORD 0 - high order word
576 	*/
577 
578 #ifdef __LP64__
579 	/*
580 	** get bits 12:15 of physical address
581 	** shift bits 16:31 of physical address
582 	** and deposit them
583 	*/
584 	asm volatile ("extrd,u %1,15,4,%0" : "=r" (ci) : "r" (pa));
585 	asm volatile ("extrd,u %1,31,16,%0" : "+r" (pa) : "r" (pa));
586 	asm volatile ("depd  %1,35,4,%0" : "+r" (pa) : "r" (ci));
587 #else
588 	pa = 0;
589 #endif
590 	/*
591 	** get CPU coherency index bits
592 	** Grab virtual index [0:11]
593 	** Deposit virt_idx bits into I/O PDIR word
594 	*/
595 	asm volatile ("lci %%r0(%1), %0" : "=r" (ci) : "r" (vba));
596 	asm volatile ("extru %1,19,12,%0" : "+r" (ci) : "r" (ci));
597 	asm volatile ("depw  %1,15,12,%0" : "+r" (pa) : "r" (ci));
598 
599 	((u32 *)pdir_ptr)[0] = (u32) pa;
600 
601 
602 	/* FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
603 	**        PCX-U/U+ do. (eg C200/C240)
604 	**        PCX-T'? Don't know. (eg C110 or similar K-class)
605 	**
606 	** See PDC_MODEL/option 0/SW_CAP word for "Non-coherent IO-PDIR bit".
607 	**
608 	** "Since PCX-U employs an offset hash that is incompatible with
609 	** the real mode coherence index generation of U2, the PDIR entry
610 	** must be flushed to memory to retain coherence."
611 	*/
612 	asm_io_fdc(pdir_ptr);
613 	asm_io_sync();
614 }
615 
616 /**
617  * ccio_clear_io_tlb - Remove stale entries from the I/O TLB.
618  * @ioc: The I/O Controller.
619  * @iovp: The I/O Virtual Page.
620  * @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
621  *
622  * Purge invalid I/O PDIR entries from the I/O TLB.
623  *
624  * FIXME: Can we change the byte_cnt to pages_mapped?
625  */
626 static void
627 ccio_clear_io_tlb(struct ioc *ioc, dma_addr_t iovp, size_t byte_cnt)
628 {
629 	u32 chain_size = 1 << ioc->chainid_shift;
630 
631 	iovp &= IOVP_MASK;	/* clear offset bits, just want pagenum */
632 	byte_cnt += chain_size;
633 
634 	while(byte_cnt > chain_size) {
635 		WRITE_U32(CMD_TLB_PURGE | iovp, &ioc->ioc_regs->io_command);
636 		iovp += chain_size;
637 		byte_cnt -= chain_size;
638 	}
639 }
640 
641 /**
642  * ccio_mark_invalid - Mark the I/O Pdir entries invalid.
643  * @ioc: The I/O Controller.
644  * @iova: The I/O Virtual Address.
645  * @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
646  *
647  * Mark the I/O Pdir entries invalid and blow away the corresponding I/O
648  * TLB entries.
649  *
650  * FIXME: at some threshold it might be "cheaper" to just blow
651  *        away the entire I/O TLB instead of individual entries.
652  *
653  * FIXME: Uturn has 256 TLB entries. We don't need to purge every
654  *        PDIR entry - just once for each possible TLB entry.
655  *        (We do need to maker I/O PDIR entries invalid regardless).
656  *
657  * FIXME: Can we change byte_cnt to pages_mapped?
658  */
659 static void
660 ccio_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
661 {
662 	u32 iovp = (u32)CCIO_IOVP(iova);
663 	size_t saved_byte_cnt;
664 
665 	/* round up to nearest page size */
666 	saved_byte_cnt = byte_cnt = ALIGN(byte_cnt, IOVP_SIZE);
667 
668 	while(byte_cnt > 0) {
669 		/* invalidate one page at a time */
670 		unsigned int idx = PDIR_INDEX(iovp);
671 		char *pdir_ptr = (char *) &(ioc->pdir_base[idx]);
672 
673 		BUG_ON(idx >= (ioc->pdir_size / sizeof(u64)));
674 		pdir_ptr[7] = 0;	/* clear only VALID bit */
675 		/*
676 		** FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
677 		**   PCX-U/U+ do. (eg C200/C240)
678 		** See PDC_MODEL/option 0/SW_CAP for "Non-coherent IO-PDIR bit".
679 		*/
680 		asm_io_fdc(pdir_ptr);
681 
682 		iovp     += IOVP_SIZE;
683 		byte_cnt -= IOVP_SIZE;
684 	}
685 
686 	asm_io_sync();
687 	ccio_clear_io_tlb(ioc, CCIO_IOVP(iova), saved_byte_cnt);
688 }
689 
690 /****************************************************************
691 **
692 **          CCIO dma_ops
693 **
694 *****************************************************************/
695 
696 /**
697  * ccio_dma_supported - Verify the IOMMU supports the DMA address range.
698  * @dev: The PCI device.
699  * @mask: A bit mask describing the DMA address range of the device.
700  */
701 static int
702 ccio_dma_supported(struct device *dev, u64 mask)
703 {
704 	if(dev == NULL) {
705 		printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
706 		BUG();
707 		return 0;
708 	}
709 
710 	/* only support 32-bit or better devices (ie PCI/GSC) */
711 	return (int)(mask >= 0xffffffffUL);
712 }
713 
714 /**
715  * ccio_map_single - Map an address range into the IOMMU.
716  * @dev: The PCI device.
717  * @addr: The start address of the DMA region.
718  * @size: The length of the DMA region.
719  * @direction: The direction of the DMA transaction (to/from device).
720  *
721  * This function implements the pci_map_single function.
722  */
723 static dma_addr_t
724 ccio_map_single(struct device *dev, void *addr, size_t size,
725 		enum dma_data_direction direction)
726 {
727 	int idx;
728 	struct ioc *ioc;
729 	unsigned long flags;
730 	dma_addr_t iovp;
731 	dma_addr_t offset;
732 	u64 *pdir_start;
733 	unsigned long hint = hint_lookup[(int)direction];
734 
735 	BUG_ON(!dev);
736 	ioc = GET_IOC(dev);
737 	if (!ioc)
738 		return DMA_MAPPING_ERROR;
739 
740 	BUG_ON(size <= 0);
741 
742 	/* save offset bits */
743 	offset = ((unsigned long) addr) & ~IOVP_MASK;
744 
745 	/* round up to nearest IOVP_SIZE */
746 	size = ALIGN(size + offset, IOVP_SIZE);
747 	spin_lock_irqsave(&ioc->res_lock, flags);
748 
749 #ifdef CCIO_COLLECT_STATS
750 	ioc->msingle_calls++;
751 	ioc->msingle_pages += size >> IOVP_SHIFT;
752 #endif
753 
754 	idx = ccio_alloc_range(ioc, dev, size);
755 	iovp = (dma_addr_t)MKIOVP(idx);
756 
757 	pdir_start = &(ioc->pdir_base[idx]);
758 
759 	DBG_RUN("%s() 0x%p -> 0x%lx size: %0x%x\n",
760 		__func__, addr, (long)iovp | offset, size);
761 
762 	/* If not cacheline aligned, force SAFE_DMA on the whole mess */
763 	if((size % L1_CACHE_BYTES) || ((unsigned long)addr % L1_CACHE_BYTES))
764 		hint |= HINT_SAFE_DMA;
765 
766 	while(size > 0) {
767 		ccio_io_pdir_entry(pdir_start, KERNEL_SPACE, (unsigned long)addr, hint);
768 
769 		DBG_RUN(" pdir %p %08x%08x\n",
770 			pdir_start,
771 			(u32) (((u32 *) pdir_start)[0]),
772 			(u32) (((u32 *) pdir_start)[1]));
773 		++pdir_start;
774 		addr += IOVP_SIZE;
775 		size -= IOVP_SIZE;
776 	}
777 
778 	spin_unlock_irqrestore(&ioc->res_lock, flags);
779 
780 	/* form complete address */
781 	return CCIO_IOVA(iovp, offset);
782 }
783 
784 
785 static dma_addr_t
786 ccio_map_page(struct device *dev, struct page *page, unsigned long offset,
787 		size_t size, enum dma_data_direction direction,
788 		unsigned long attrs)
789 {
790 	return ccio_map_single(dev, page_address(page) + offset, size,
791 			direction);
792 }
793 
794 
795 /**
796  * ccio_unmap_page - Unmap an address range from the IOMMU.
797  * @dev: The PCI device.
798  * @iova: The start address of the DMA region.
799  * @size: The length of the DMA region.
800  * @direction: The direction of the DMA transaction (to/from device).
801  * @attrs: attributes
802  */
803 static void
804 ccio_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
805 		enum dma_data_direction direction, unsigned long attrs)
806 {
807 	struct ioc *ioc;
808 	unsigned long flags;
809 	dma_addr_t offset = iova & ~IOVP_MASK;
810 
811 	BUG_ON(!dev);
812 	ioc = GET_IOC(dev);
813 	if (!ioc) {
814 		WARN_ON(!ioc);
815 		return;
816 	}
817 
818 	DBG_RUN("%s() iovp 0x%lx/%x\n",
819 		__func__, (long)iova, size);
820 
821 	iova ^= offset;        /* clear offset bits */
822 	size += offset;
823 	size = ALIGN(size, IOVP_SIZE);
824 
825 	spin_lock_irqsave(&ioc->res_lock, flags);
826 
827 #ifdef CCIO_COLLECT_STATS
828 	ioc->usingle_calls++;
829 	ioc->usingle_pages += size >> IOVP_SHIFT;
830 #endif
831 
832 	ccio_mark_invalid(ioc, iova, size);
833 	ccio_free_range(ioc, iova, (size >> IOVP_SHIFT));
834 	spin_unlock_irqrestore(&ioc->res_lock, flags);
835 }
836 
837 /**
838  * ccio_alloc - Allocate a consistent DMA mapping.
839  * @dev: The PCI device.
840  * @size: The length of the DMA region.
841  * @dma_handle: The DMA address handed back to the device (not the cpu).
842  * @flag: allocation flags
843  * @attrs: attributes
844  *
845  * This function implements the pci_alloc_consistent function.
846  */
847 static void *
848 ccio_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag,
849 		unsigned long attrs)
850 {
851 	void *ret;
852 #if 0
853 /* GRANT Need to establish hierarchy for non-PCI devs as well
854 ** and then provide matching gsc_map_xxx() functions for them as well.
855 */
856 	if(!hwdev) {
857 		/* only support PCI */
858 		*dma_handle = 0;
859 		return 0;
860 	}
861 #endif
862 	ret = (void *) __get_free_pages(flag, get_order(size));
863 
864 	if (ret) {
865 		memset(ret, 0, size);
866 		*dma_handle = ccio_map_single(dev, ret, size, DMA_BIDIRECTIONAL);
867 	}
868 
869 	return ret;
870 }
871 
872 /**
873  * ccio_free - Free a consistent DMA mapping.
874  * @dev: The PCI device.
875  * @size: The length of the DMA region.
876  * @cpu_addr: The cpu address returned from the ccio_alloc_consistent.
877  * @dma_handle: The device address returned from the ccio_alloc_consistent.
878  * @attrs: attributes
879  *
880  * This function implements the pci_free_consistent function.
881  */
882 static void
883 ccio_free(struct device *dev, size_t size, void *cpu_addr,
884 		dma_addr_t dma_handle, unsigned long attrs)
885 {
886 	ccio_unmap_page(dev, dma_handle, size, 0, 0);
887 	free_pages((unsigned long)cpu_addr, get_order(size));
888 }
889 
890 /*
891 ** Since 0 is a valid pdir_base index value, can't use that
892 ** to determine if a value is valid or not. Use a flag to indicate
893 ** the SG list entry contains a valid pdir index.
894 */
895 #define PIDE_FLAG 0x80000000UL
896 
897 #ifdef CCIO_COLLECT_STATS
898 #define IOMMU_MAP_STATS
899 #endif
900 #include "iommu-helpers.h"
901 
902 /**
903  * ccio_map_sg - Map the scatter/gather list into the IOMMU.
904  * @dev: The PCI device.
905  * @sglist: The scatter/gather list to be mapped in the IOMMU.
906  * @nents: The number of entries in the scatter/gather list.
907  * @direction: The direction of the DMA transaction (to/from device).
908  * @attrs: attributes
909  *
910  * This function implements the pci_map_sg function.
911  */
912 static int
913 ccio_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
914 	    enum dma_data_direction direction, unsigned long attrs)
915 {
916 	struct ioc *ioc;
917 	int coalesced, filled = 0;
918 	unsigned long flags;
919 	unsigned long hint = hint_lookup[(int)direction];
920 	unsigned long prev_len = 0, current_len = 0;
921 	int i;
922 
923 	BUG_ON(!dev);
924 	ioc = GET_IOC(dev);
925 	if (!ioc)
926 		return -EINVAL;
927 
928 	DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
929 
930 	/* Fast path single entry scatterlists. */
931 	if (nents == 1) {
932 		sg_dma_address(sglist) = ccio_map_single(dev,
933 				sg_virt(sglist), sglist->length,
934 				direction);
935 		sg_dma_len(sglist) = sglist->length;
936 		return 1;
937 	}
938 
939 	for(i = 0; i < nents; i++)
940 		prev_len += sglist[i].length;
941 
942 	spin_lock_irqsave(&ioc->res_lock, flags);
943 
944 #ifdef CCIO_COLLECT_STATS
945 	ioc->msg_calls++;
946 #endif
947 
948 	/*
949 	** First coalesce the chunks and allocate I/O pdir space
950 	**
951 	** If this is one DMA stream, we can properly map using the
952 	** correct virtual address associated with each DMA page.
953 	** w/o this association, we wouldn't have coherent DMA!
954 	** Access to the virtual address is what forces a two pass algorithm.
955 	*/
956 	coalesced = iommu_coalesce_chunks(ioc, dev, sglist, nents, ccio_alloc_range);
957 
958 	/*
959 	** Program the I/O Pdir
960 	**
961 	** map the virtual addresses to the I/O Pdir
962 	** o dma_address will contain the pdir index
963 	** o dma_len will contain the number of bytes to map
964 	** o page/offset contain the virtual address.
965 	*/
966 	filled = iommu_fill_pdir(ioc, sglist, nents, hint, ccio_io_pdir_entry);
967 
968 	spin_unlock_irqrestore(&ioc->res_lock, flags);
969 
970 	BUG_ON(coalesced != filled);
971 
972 	DBG_RUN_SG("%s() DONE %d mappings\n", __func__, filled);
973 
974 	for (i = 0; i < filled; i++)
975 		current_len += sg_dma_len(sglist + i);
976 
977 	BUG_ON(current_len != prev_len);
978 
979 	return filled;
980 }
981 
982 /**
983  * ccio_unmap_sg - Unmap the scatter/gather list from the IOMMU.
984  * @dev: The PCI device.
985  * @sglist: The scatter/gather list to be unmapped from the IOMMU.
986  * @nents: The number of entries in the scatter/gather list.
987  * @direction: The direction of the DMA transaction (to/from device).
988  * @attrs: attributes
989  *
990  * This function implements the pci_unmap_sg function.
991  */
992 static void
993 ccio_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
994 	      enum dma_data_direction direction, unsigned long attrs)
995 {
996 	struct ioc *ioc;
997 
998 	BUG_ON(!dev);
999 	ioc = GET_IOC(dev);
1000 	if (!ioc) {
1001 		WARN_ON(!ioc);
1002 		return;
1003 	}
1004 
1005 	DBG_RUN_SG("%s() START %d entries, %p,%x\n",
1006 		__func__, nents, sg_virt(sglist), sglist->length);
1007 
1008 #ifdef CCIO_COLLECT_STATS
1009 	ioc->usg_calls++;
1010 #endif
1011 
1012 	while (nents && sg_dma_len(sglist)) {
1013 
1014 #ifdef CCIO_COLLECT_STATS
1015 		ioc->usg_pages += sg_dma_len(sglist) >> PAGE_SHIFT;
1016 #endif
1017 		ccio_unmap_page(dev, sg_dma_address(sglist),
1018 				  sg_dma_len(sglist), direction, 0);
1019 		++sglist;
1020 		nents--;
1021 	}
1022 
1023 	DBG_RUN_SG("%s() DONE (nents %d)\n", __func__, nents);
1024 }
1025 
1026 static const struct dma_map_ops ccio_ops = {
1027 	.dma_supported =	ccio_dma_supported,
1028 	.alloc =		ccio_alloc,
1029 	.free =			ccio_free,
1030 	.map_page =		ccio_map_page,
1031 	.unmap_page =		ccio_unmap_page,
1032 	.map_sg =		ccio_map_sg,
1033 	.unmap_sg =		ccio_unmap_sg,
1034 	.get_sgtable =		dma_common_get_sgtable,
1035 	.alloc_pages =		dma_common_alloc_pages,
1036 	.free_pages =		dma_common_free_pages,
1037 };
1038 
1039 #ifdef CONFIG_PROC_FS
1040 static int ccio_proc_info(struct seq_file *m, void *p)
1041 {
1042 	struct ioc *ioc = ioc_list;
1043 
1044 	while (ioc != NULL) {
1045 		unsigned int total_pages = ioc->res_size << 3;
1046 #ifdef CCIO_COLLECT_STATS
1047 		unsigned long avg = 0, min, max;
1048 		int j;
1049 #endif
1050 
1051 		seq_printf(m, "%s\n", ioc->name);
1052 
1053 		seq_printf(m, "Cujo 2.0 bug    : %s\n",
1054 			   (ioc->cujo20_bug ? "yes" : "no"));
1055 
1056 		seq_printf(m, "IO PDIR size    : %d bytes (%d entries)\n",
1057 			   total_pages * 8, total_pages);
1058 
1059 #ifdef CCIO_COLLECT_STATS
1060 		seq_printf(m, "IO PDIR entries : %ld free  %ld used (%d%%)\n",
1061 			   total_pages - ioc->used_pages, ioc->used_pages,
1062 			   (int)(ioc->used_pages * 100 / total_pages));
1063 #endif
1064 
1065 		seq_printf(m, "Resource bitmap : %d bytes (%d pages)\n",
1066 			   ioc->res_size, total_pages);
1067 
1068 #ifdef CCIO_COLLECT_STATS
1069 		min = max = ioc->avg_search[0];
1070 		for(j = 0; j < CCIO_SEARCH_SAMPLE; ++j) {
1071 			avg += ioc->avg_search[j];
1072 			if(ioc->avg_search[j] > max)
1073 				max = ioc->avg_search[j];
1074 			if(ioc->avg_search[j] < min)
1075 				min = ioc->avg_search[j];
1076 		}
1077 		avg /= CCIO_SEARCH_SAMPLE;
1078 		seq_printf(m, "  Bitmap search : %ld/%ld/%ld (min/avg/max CPU Cycles)\n",
1079 			   min, avg, max);
1080 
1081 		seq_printf(m, "pci_map_single(): %8ld calls  %8ld pages (avg %d/1000)\n",
1082 			   ioc->msingle_calls, ioc->msingle_pages,
1083 			   (int)((ioc->msingle_pages * 1000)/ioc->msingle_calls));
1084 
1085 		/* KLUGE - unmap_sg calls unmap_page for each mapped page */
1086 		min = ioc->usingle_calls - ioc->usg_calls;
1087 		max = ioc->usingle_pages - ioc->usg_pages;
1088 		seq_printf(m, "pci_unmap_single: %8ld calls  %8ld pages (avg %d/1000)\n",
1089 			   min, max, (int)((max * 1000)/min));
1090 
1091 		seq_printf(m, "pci_map_sg()    : %8ld calls  %8ld pages (avg %d/1000)\n",
1092 			   ioc->msg_calls, ioc->msg_pages,
1093 			   (int)((ioc->msg_pages * 1000)/ioc->msg_calls));
1094 
1095 		seq_printf(m, "pci_unmap_sg()  : %8ld calls  %8ld pages (avg %d/1000)\n\n\n",
1096 			   ioc->usg_calls, ioc->usg_pages,
1097 			   (int)((ioc->usg_pages * 1000)/ioc->usg_calls));
1098 #endif	/* CCIO_COLLECT_STATS */
1099 
1100 		ioc = ioc->next;
1101 	}
1102 
1103 	return 0;
1104 }
1105 
1106 static int ccio_proc_bitmap_info(struct seq_file *m, void *p)
1107 {
1108 	struct ioc *ioc = ioc_list;
1109 
1110 	while (ioc != NULL) {
1111 		seq_hex_dump(m, "   ", DUMP_PREFIX_NONE, 32, 4, ioc->res_map,
1112 			     ioc->res_size, false);
1113 		seq_putc(m, '\n');
1114 		ioc = ioc->next;
1115 		break; /* XXX - remove me */
1116 	}
1117 
1118 	return 0;
1119 }
1120 #endif /* CONFIG_PROC_FS */
1121 
1122 /**
1123  * ccio_find_ioc - Find the ioc in the ioc_list
1124  * @hw_path: The hardware path of the ioc.
1125  *
1126  * This function searches the ioc_list for an ioc that matches
1127  * the provide hardware path.
1128  */
1129 static struct ioc * ccio_find_ioc(int hw_path)
1130 {
1131 	int i;
1132 	struct ioc *ioc;
1133 
1134 	ioc = ioc_list;
1135 	for (i = 0; i < ioc_count; i++) {
1136 		if (ioc->hw_path == hw_path)
1137 			return ioc;
1138 
1139 		ioc = ioc->next;
1140 	}
1141 
1142 	return NULL;
1143 }
1144 
1145 /**
1146  * ccio_get_iommu - Find the iommu which controls this device
1147  * @dev: The parisc device.
1148  *
1149  * This function searches through the registered IOMMU's and returns
1150  * the appropriate IOMMU for the device based on its hardware path.
1151  */
1152 void * ccio_get_iommu(const struct parisc_device *dev)
1153 {
1154 	dev = find_pa_parent_type(dev, HPHW_IOA);
1155 	if (!dev)
1156 		return NULL;
1157 
1158 	return ccio_find_ioc(dev->hw_path);
1159 }
1160 
1161 #define CUJO_20_STEP       0x10000000	/* inc upper nibble */
1162 
1163 /* Cujo 2.0 has a bug which will silently corrupt data being transferred
1164  * to/from certain pages.  To avoid this happening, we mark these pages
1165  * as `used', and ensure that nothing will try to allocate from them.
1166  */
1167 void __init ccio_cujo20_fixup(struct parisc_device *cujo, u32 iovp)
1168 {
1169 	unsigned int idx;
1170 	struct parisc_device *dev = parisc_parent(cujo);
1171 	struct ioc *ioc = ccio_get_iommu(dev);
1172 	u8 *res_ptr;
1173 
1174 	ioc->cujo20_bug = 1;
1175 	res_ptr = ioc->res_map;
1176 	idx = PDIR_INDEX(iovp) >> 3;
1177 
1178 	while (idx < ioc->res_size) {
1179 		res_ptr[idx] |= 0xff;
1180 		idx += PDIR_INDEX(CUJO_20_STEP) >> 3;
1181 	}
1182 }
1183 
1184 #if 0
1185 /* GRANT -  is this needed for U2 or not? */
1186 
1187 /*
1188 ** Get the size of the I/O TLB for this I/O MMU.
1189 **
1190 ** If spa_shift is non-zero (ie probably U2),
1191 ** then calculate the I/O TLB size using spa_shift.
1192 **
1193 ** Otherwise we are supposed to get the IODC entry point ENTRY TLB
1194 ** and execute it. However, both U2 and Uturn firmware supplies spa_shift.
1195 ** I think only Java (K/D/R-class too?) systems don't do this.
1196 */
1197 static int
1198 ccio_get_iotlb_size(struct parisc_device *dev)
1199 {
1200 	if (dev->spa_shift == 0) {
1201 		panic("%s() : Can't determine I/O TLB size.\n", __func__);
1202 	}
1203 	return (1 << dev->spa_shift);
1204 }
1205 #else
1206 
1207 /* Uturn supports 256 TLB entries */
1208 #define CCIO_CHAINID_SHIFT	8
1209 #define CCIO_CHAINID_MASK	0xff
1210 #endif /* 0 */
1211 
1212 /* We *can't* support JAVA (T600). Venture there at your own risk. */
1213 static const struct parisc_device_id ccio_tbl[] __initconst = {
1214 	{ HPHW_IOA, HVERSION_REV_ANY_ID, U2_IOA_RUNWAY, 0xb }, /* U2 */
1215 	{ HPHW_IOA, HVERSION_REV_ANY_ID, UTURN_IOA_RUNWAY, 0xb }, /* UTurn */
1216 	{ 0, }
1217 };
1218 
1219 static int ccio_probe(struct parisc_device *dev);
1220 
1221 static struct parisc_driver ccio_driver __refdata = {
1222 	.name =		"ccio",
1223 	.id_table =	ccio_tbl,
1224 	.probe =	ccio_probe,
1225 };
1226 
1227 /**
1228  * ccio_ioc_init - Initialize the I/O Controller
1229  * @ioc: The I/O Controller.
1230  *
1231  * Initialize the I/O Controller which includes setting up the
1232  * I/O Page Directory, the resource map, and initalizing the
1233  * U2/Uturn chip into virtual mode.
1234  */
1235 static void __init
1236 ccio_ioc_init(struct ioc *ioc)
1237 {
1238 	int i;
1239 	unsigned int iov_order;
1240 	u32 iova_space_size;
1241 
1242 	/*
1243 	** Determine IOVA Space size from memory size.
1244 	**
1245 	** Ideally, PCI drivers would register the maximum number
1246 	** of DMA they can have outstanding for each device they
1247 	** own.  Next best thing would be to guess how much DMA
1248 	** can be outstanding based on PCI Class/sub-class. Both
1249 	** methods still require some "extra" to support PCI
1250 	** Hot-Plug/Removal of PCI cards. (aka PCI OLARD).
1251 	*/
1252 
1253 	iova_space_size = (u32) (totalram_pages() / count_parisc_driver(&ccio_driver));
1254 
1255 	/* limit IOVA space size to 1MB-1GB */
1256 
1257 	if (iova_space_size < (1 << (20 - PAGE_SHIFT))) {
1258 		iova_space_size =  1 << (20 - PAGE_SHIFT);
1259 #ifdef __LP64__
1260 	} else if (iova_space_size > (1 << (30 - PAGE_SHIFT))) {
1261 		iova_space_size =  1 << (30 - PAGE_SHIFT);
1262 #endif
1263 	}
1264 
1265 	/*
1266 	** iova space must be log2() in size.
1267 	** thus, pdir/res_map will also be log2().
1268 	*/
1269 
1270 	/* We could use larger page sizes in order to *decrease* the number
1271 	** of mappings needed.  (ie 8k pages means 1/2 the mappings).
1272 	**
1273 	** Note: Grant Grunder says "Using 8k I/O pages isn't trivial either
1274 	**   since the pages must also be physically contiguous - typically
1275 	**   this is the case under linux."
1276 	*/
1277 
1278 	iov_order = get_order(iova_space_size << PAGE_SHIFT);
1279 
1280 	/* iova_space_size is now bytes, not pages */
1281 	iova_space_size = 1 << (iov_order + PAGE_SHIFT);
1282 
1283 	ioc->pdir_size = (iova_space_size / IOVP_SIZE) * sizeof(u64);
1284 
1285 	BUG_ON(ioc->pdir_size > 8 * 1024 * 1024);   /* max pdir size <= 8MB */
1286 
1287 	/* Verify it's a power of two */
1288 	BUG_ON((1 << get_order(ioc->pdir_size)) != (ioc->pdir_size >> PAGE_SHIFT));
1289 
1290 	DBG_INIT("%s() hpa 0x%p mem %luMB IOV %dMB (%d bits)\n",
1291 			__func__, ioc->ioc_regs,
1292 			(unsigned long) totalram_pages() >> (20 - PAGE_SHIFT),
1293 			iova_space_size>>20,
1294 			iov_order + PAGE_SHIFT);
1295 
1296 	ioc->pdir_base = (u64 *)__get_free_pages(GFP_KERNEL,
1297 						 get_order(ioc->pdir_size));
1298 	if(NULL == ioc->pdir_base) {
1299 		panic("%s() could not allocate I/O Page Table\n", __func__);
1300 	}
1301 	memset(ioc->pdir_base, 0, ioc->pdir_size);
1302 
1303 	BUG_ON((((unsigned long)ioc->pdir_base) & PAGE_MASK) != (unsigned long)ioc->pdir_base);
1304 	DBG_INIT(" base %p\n", ioc->pdir_base);
1305 
1306 	/* resource map size dictated by pdir_size */
1307 	ioc->res_size = (ioc->pdir_size / sizeof(u64)) >> 3;
1308 	DBG_INIT("%s() res_size 0x%x\n", __func__, ioc->res_size);
1309 
1310 	ioc->res_map = (u8 *)__get_free_pages(GFP_KERNEL,
1311 					      get_order(ioc->res_size));
1312 	if(NULL == ioc->res_map) {
1313 		panic("%s() could not allocate resource map\n", __func__);
1314 	}
1315 	memset(ioc->res_map, 0, ioc->res_size);
1316 
1317 	/* Initialize the res_hint to 16 */
1318 	ioc->res_hint = 16;
1319 
1320 	/* Initialize the spinlock */
1321 	spin_lock_init(&ioc->res_lock);
1322 
1323 	/*
1324 	** Chainid is the upper most bits of an IOVP used to determine
1325 	** which TLB entry an IOVP will use.
1326 	*/
1327 	ioc->chainid_shift = get_order(iova_space_size) + PAGE_SHIFT - CCIO_CHAINID_SHIFT;
1328 	DBG_INIT(" chainid_shift 0x%x\n", ioc->chainid_shift);
1329 
1330 	/*
1331 	** Initialize IOA hardware
1332 	*/
1333 	WRITE_U32(CCIO_CHAINID_MASK << ioc->chainid_shift,
1334 		  &ioc->ioc_regs->io_chain_id_mask);
1335 
1336 	WRITE_U32(virt_to_phys(ioc->pdir_base),
1337 		  &ioc->ioc_regs->io_pdir_base);
1338 
1339 	/*
1340 	** Go to "Virtual Mode"
1341 	*/
1342 	WRITE_U32(IOA_NORMAL_MODE, &ioc->ioc_regs->io_control);
1343 
1344 	/*
1345 	** Initialize all I/O TLB entries to 0 (Valid bit off).
1346 	*/
1347 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_m);
1348 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_l);
1349 
1350 	for(i = 1 << CCIO_CHAINID_SHIFT; i ; i--) {
1351 		WRITE_U32((CMD_TLB_DIRECT_WRITE | (i << ioc->chainid_shift)),
1352 			  &ioc->ioc_regs->io_command);
1353 	}
1354 }
1355 
1356 static void __init
1357 ccio_init_resource(struct resource *res, char *name, void __iomem *ioaddr)
1358 {
1359 	int result;
1360 
1361 	res->parent = NULL;
1362 	res->flags = IORESOURCE_MEM;
1363 	/*
1364 	 * bracing ((signed) ...) are required for 64bit kernel because
1365 	 * we only want to sign extend the lower 16 bits of the register.
1366 	 * The upper 16-bits of range registers are hardcoded to 0xffff.
1367 	 */
1368 	res->start = (unsigned long)((signed) READ_U32(ioaddr) << 16);
1369 	res->end = (unsigned long)((signed) (READ_U32(ioaddr + 4) << 16) - 1);
1370 	res->name = name;
1371 	/*
1372 	 * Check if this MMIO range is disable
1373 	 */
1374 	if (res->end + 1 == res->start)
1375 		return;
1376 
1377 	/* On some platforms (e.g. K-Class), we have already registered
1378 	 * resources for devices reported by firmware. Some are children
1379 	 * of ccio.
1380 	 * "insert" ccio ranges in the mmio hierarchy (/proc/iomem).
1381 	 */
1382 	result = insert_resource(&iomem_resource, res);
1383 	if (result < 0) {
1384 		printk(KERN_ERR "%s() failed to claim CCIO bus address space (%08lx,%08lx)\n",
1385 			__func__, (unsigned long)res->start, (unsigned long)res->end);
1386 	}
1387 }
1388 
1389 static int __init ccio_init_resources(struct ioc *ioc)
1390 {
1391 	struct resource *res = ioc->mmio_region;
1392 	char *name = kmalloc(14, GFP_KERNEL);
1393 	if (unlikely(!name))
1394 		return -ENOMEM;
1395 	snprintf(name, 14, "GSC Bus [%d/]", ioc->hw_path);
1396 
1397 	ccio_init_resource(res, name, &ioc->ioc_regs->io_io_low);
1398 	ccio_init_resource(res + 1, name, &ioc->ioc_regs->io_io_low_hv);
1399 	return 0;
1400 }
1401 
1402 static int new_ioc_area(struct resource *res, unsigned long size,
1403 		unsigned long min, unsigned long max, unsigned long align)
1404 {
1405 	if (max <= min)
1406 		return -EBUSY;
1407 
1408 	res->start = (max - size + 1) &~ (align - 1);
1409 	res->end = res->start + size;
1410 
1411 	/* We might be trying to expand the MMIO range to include
1412 	 * a child device that has already registered it's MMIO space.
1413 	 * Use "insert" instead of request_resource().
1414 	 */
1415 	if (!insert_resource(&iomem_resource, res))
1416 		return 0;
1417 
1418 	return new_ioc_area(res, size, min, max - size, align);
1419 }
1420 
1421 static int expand_ioc_area(struct resource *res, unsigned long size,
1422 		unsigned long min, unsigned long max, unsigned long align)
1423 {
1424 	unsigned long start, len;
1425 
1426 	if (!res->parent)
1427 		return new_ioc_area(res, size, min, max, align);
1428 
1429 	start = (res->start - size) &~ (align - 1);
1430 	len = res->end - start + 1;
1431 	if (start >= min) {
1432 		if (!adjust_resource(res, start, len))
1433 			return 0;
1434 	}
1435 
1436 	start = res->start;
1437 	len = ((size + res->end + align) &~ (align - 1)) - start;
1438 	if (start + len <= max) {
1439 		if (!adjust_resource(res, start, len))
1440 			return 0;
1441 	}
1442 
1443 	return -EBUSY;
1444 }
1445 
1446 /*
1447  * Dino calls this function.  Beware that we may get called on systems
1448  * which have no IOC (725, B180, C160L, etc) but do have a Dino.
1449  * So it's legal to find no parent IOC.
1450  *
1451  * Some other issues: one of the resources in the ioc may be unassigned.
1452  */
1453 int ccio_allocate_resource(const struct parisc_device *dev,
1454 		struct resource *res, unsigned long size,
1455 		unsigned long min, unsigned long max, unsigned long align)
1456 {
1457 	struct resource *parent = &iomem_resource;
1458 	struct ioc *ioc = ccio_get_iommu(dev);
1459 	if (!ioc)
1460 		goto out;
1461 
1462 	parent = ioc->mmio_region;
1463 	if (parent->parent &&
1464 	    !allocate_resource(parent, res, size, min, max, align, NULL, NULL))
1465 		return 0;
1466 
1467 	if ((parent + 1)->parent &&
1468 	    !allocate_resource(parent + 1, res, size, min, max, align,
1469 				NULL, NULL))
1470 		return 0;
1471 
1472 	if (!expand_ioc_area(parent, size, min, max, align)) {
1473 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1474 			     &ioc->ioc_regs->io_io_low);
1475 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1476 			     &ioc->ioc_regs->io_io_high);
1477 	} else if (!expand_ioc_area(parent + 1, size, min, max, align)) {
1478 		parent++;
1479 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1480 			     &ioc->ioc_regs->io_io_low_hv);
1481 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1482 			     &ioc->ioc_regs->io_io_high_hv);
1483 	} else {
1484 		return -EBUSY;
1485 	}
1486 
1487  out:
1488 	return allocate_resource(parent, res, size, min, max, align, NULL,NULL);
1489 }
1490 
1491 int ccio_request_resource(const struct parisc_device *dev,
1492 		struct resource *res)
1493 {
1494 	struct resource *parent;
1495 	struct ioc *ioc = ccio_get_iommu(dev);
1496 
1497 	if (!ioc) {
1498 		parent = &iomem_resource;
1499 	} else if ((ioc->mmio_region->start <= res->start) &&
1500 			(res->end <= ioc->mmio_region->end)) {
1501 		parent = ioc->mmio_region;
1502 	} else if (((ioc->mmio_region + 1)->start <= res->start) &&
1503 			(res->end <= (ioc->mmio_region + 1)->end)) {
1504 		parent = ioc->mmio_region + 1;
1505 	} else {
1506 		return -EBUSY;
1507 	}
1508 
1509 	/* "transparent" bus bridges need to register MMIO resources
1510 	 * firmware assigned them. e.g. children of hppb.c (e.g. K-class)
1511 	 * registered their resources in the PDC "bus walk" (See
1512 	 * arch/parisc/kernel/inventory.c).
1513 	 */
1514 	return insert_resource(parent, res);
1515 }
1516 
1517 /**
1518  * ccio_probe - Determine if ccio should claim this device.
1519  * @dev: The device which has been found
1520  *
1521  * Determine if ccio should claim this chip (return 0) or not (return 1).
1522  * If so, initialize the chip and tell other partners in crime they
1523  * have work to do.
1524  */
1525 static int __init ccio_probe(struct parisc_device *dev)
1526 {
1527 	int i;
1528 	struct ioc *ioc, **ioc_p = &ioc_list;
1529 	struct pci_hba_data *hba;
1530 
1531 	ioc = kzalloc(sizeof(struct ioc), GFP_KERNEL);
1532 	if (ioc == NULL) {
1533 		printk(KERN_ERR MODULE_NAME ": memory allocation failure\n");
1534 		return -ENOMEM;
1535 	}
1536 
1537 	ioc->name = dev->id.hversion == U2_IOA_RUNWAY ? "U2" : "UTurn";
1538 
1539 	printk(KERN_INFO "Found %s at 0x%lx\n", ioc->name,
1540 		(unsigned long)dev->hpa.start);
1541 
1542 	for (i = 0; i < ioc_count; i++) {
1543 		ioc_p = &(*ioc_p)->next;
1544 	}
1545 	*ioc_p = ioc;
1546 
1547 	ioc->hw_path = dev->hw_path;
1548 	ioc->ioc_regs = ioremap(dev->hpa.start, 4096);
1549 	if (!ioc->ioc_regs) {
1550 		kfree(ioc);
1551 		return -ENOMEM;
1552 	}
1553 	ccio_ioc_init(ioc);
1554 	if (ccio_init_resources(ioc)) {
1555 		iounmap(ioc->ioc_regs);
1556 		kfree(ioc);
1557 		return -ENOMEM;
1558 	}
1559 	hppa_dma_ops = &ccio_ops;
1560 
1561 	hba = kzalloc(sizeof(*hba), GFP_KERNEL);
1562 	/* if this fails, no I/O cards will work, so may as well bug */
1563 	BUG_ON(hba == NULL);
1564 
1565 	hba->iommu = ioc;
1566 	dev->dev.platform_data = hba;
1567 
1568 #ifdef CONFIG_PROC_FS
1569 	if (ioc_count == 0) {
1570 		proc_create_single(MODULE_NAME, 0, proc_runway_root,
1571 				ccio_proc_info);
1572 		proc_create_single(MODULE_NAME"-bitmap", 0, proc_runway_root,
1573 				ccio_proc_bitmap_info);
1574 	}
1575 #endif
1576 	ioc_count++;
1577 	return 0;
1578 }
1579 
1580 /**
1581  * ccio_init - ccio initialization procedure.
1582  *
1583  * Register this driver.
1584  */
1585 void __init ccio_init(void)
1586 {
1587 	register_parisc_driver(&ccio_driver);
1588 }
1589 
1590