xref: /openbmc/linux/drivers/parisc/ccio-dma.c (revision 8730046c)
1 /*
2 ** ccio-dma.c:
3 **	DMA management routines for first generation cache-coherent machines.
4 **	Program U2/Uturn in "Virtual Mode" and use the I/O MMU.
5 **
6 **	(c) Copyright 2000 Grant Grundler
7 **	(c) Copyright 2000 Ryan Bradetich
8 **	(c) Copyright 2000 Hewlett-Packard Company
9 **
10 ** This program is free software; you can redistribute it and/or modify
11 ** it under the terms of the GNU General Public License as published by
12 ** the Free Software Foundation; either version 2 of the License, or
13 ** (at your option) any later version.
14 **
15 **
16 **  "Real Mode" operation refers to U2/Uturn chip operation.
17 **  U2/Uturn were designed to perform coherency checks w/o using
18 **  the I/O MMU - basically what x86 does.
19 **
20 **  Philipp Rumpf has a "Real Mode" driver for PCX-W machines at:
21 **      CVSROOT=:pserver:anonymous@198.186.203.37:/cvsroot/linux-parisc
22 **      cvs -z3 co linux/arch/parisc/kernel/dma-rm.c
23 **
24 **  I've rewritten his code to work under TPG's tree. See ccio-rm-dma.c.
25 **
26 **  Drawbacks of using Real Mode are:
27 **	o outbound DMA is slower - U2 won't prefetch data (GSC+ XQL signal).
28 **      o Inbound DMA less efficient - U2 can't use DMA_FAST attribute.
29 **	o Ability to do scatter/gather in HW is lost.
30 **	o Doesn't work under PCX-U/U+ machines since they didn't follow
31 **        the coherency design originally worked out. Only PCX-W does.
32 */
33 
34 #include <linux/types.h>
35 #include <linux/kernel.h>
36 #include <linux/init.h>
37 #include <linux/mm.h>
38 #include <linux/spinlock.h>
39 #include <linux/slab.h>
40 #include <linux/string.h>
41 #include <linux/pci.h>
42 #include <linux/reboot.h>
43 #include <linux/proc_fs.h>
44 #include <linux/seq_file.h>
45 #include <linux/scatterlist.h>
46 #include <linux/iommu-helper.h>
47 #include <linux/export.h>
48 
49 #include <asm/byteorder.h>
50 #include <asm/cache.h>		/* for L1_CACHE_BYTES */
51 #include <linux/uaccess.h>
52 #include <asm/page.h>
53 #include <asm/dma.h>
54 #include <asm/io.h>
55 #include <asm/hardware.h>       /* for register_module() */
56 #include <asm/parisc-device.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 CCIO_INLINE	inline
101 #define WRITE_U32(value, addr) __raw_writel(value, addr)
102 #define READ_U32(addr) __raw_readl(addr)
103 
104 #define U2_IOA_RUNWAY 0x580
105 #define U2_BC_GSC     0x501
106 #define UTURN_IOA_RUNWAY 0x581
107 #define UTURN_BC_GSC     0x502
108 
109 #define IOA_NORMAL_MODE      0x00020080 /* IO_CONTROL to turn on CCIO        */
110 #define CMD_TLB_DIRECT_WRITE 35         /* IO_COMMAND for I/O TLB Writes     */
111 #define CMD_TLB_PURGE        33         /* IO_COMMAND to Purge I/O TLB entry */
112 
113 struct ioa_registers {
114         /* Runway Supervisory Set */
115         int32_t    unused1[12];
116         uint32_t   io_command;             /* Offset 12 */
117         uint32_t   io_status;              /* Offset 13 */
118         uint32_t   io_control;             /* Offset 14 */
119         int32_t    unused2[1];
120 
121         /* Runway Auxiliary Register Set */
122         uint32_t   io_err_resp;            /* Offset  0 */
123         uint32_t   io_err_info;            /* Offset  1 */
124         uint32_t   io_err_req;             /* Offset  2 */
125         uint32_t   io_err_resp_hi;         /* Offset  3 */
126         uint32_t   io_tlb_entry_m;         /* Offset  4 */
127         uint32_t   io_tlb_entry_l;         /* Offset  5 */
128         uint32_t   unused3[1];
129         uint32_t   io_pdir_base;           /* Offset  7 */
130         uint32_t   io_io_low_hv;           /* Offset  8 */
131         uint32_t   io_io_high_hv;          /* Offset  9 */
132         uint32_t   unused4[1];
133         uint32_t   io_chain_id_mask;       /* Offset 11 */
134         uint32_t   unused5[2];
135         uint32_t   io_io_low;              /* Offset 14 */
136         uint32_t   io_io_high;             /* Offset 15 */
137 };
138 
139 /*
140 ** IOA Registers
141 ** -------------
142 **
143 ** Runway IO_CONTROL Register (+0x38)
144 **
145 ** The Runway IO_CONTROL register controls the forwarding of transactions.
146 **
147 ** | 0  ...  13  |  14 15 | 16 ... 21 | 22 | 23 24 |  25 ... 31 |
148 ** |    HV       |   TLB  |  reserved | HV | mode  |  reserved  |
149 **
150 ** o mode field indicates the address translation of transactions
151 **   forwarded from Runway to GSC+:
152 **       Mode Name     Value        Definition
153 **       Off (default)   0          Opaque to matching addresses.
154 **       Include         1          Transparent for matching addresses.
155 **       Peek            3          Map matching addresses.
156 **
157 **       + "Off" mode: Runway transactions which match the I/O range
158 **         specified by the IO_IO_LOW/IO_IO_HIGH registers will be ignored.
159 **       + "Include" mode: all addresses within the I/O range specified
160 **         by the IO_IO_LOW and IO_IO_HIGH registers are transparently
161 **         forwarded. This is the I/O Adapter's normal operating mode.
162 **       + "Peek" mode: used during system configuration to initialize the
163 **         GSC+ bus. Runway Write_Shorts in the address range specified by
164 **         IO_IO_LOW and IO_IO_HIGH are forwarded through the I/O Adapter
165 **         *AND* the GSC+ address is remapped to the Broadcast Physical
166 **         Address space by setting the 14 high order address bits of the
167 **         32 bit GSC+ address to ones.
168 **
169 ** o TLB field affects transactions which are forwarded from GSC+ to Runway.
170 **   "Real" mode is the poweron default.
171 **
172 **   TLB Mode  Value  Description
173 **   Real        0    No TLB translation. Address is directly mapped and the
174 **                    virtual address is composed of selected physical bits.
175 **   Error       1    Software fills the TLB manually.
176 **   Normal      2    IOA fetches IO TLB misses from IO PDIR (in host memory).
177 **
178 **
179 ** IO_IO_LOW_HV	  +0x60 (HV dependent)
180 ** IO_IO_HIGH_HV  +0x64 (HV dependent)
181 ** IO_IO_LOW      +0x78	(Architected register)
182 ** IO_IO_HIGH     +0x7c	(Architected register)
183 **
184 ** IO_IO_LOW and IO_IO_HIGH set the lower and upper bounds of the
185 ** I/O Adapter address space, respectively.
186 **
187 ** 0  ... 7 | 8 ... 15 |  16   ...   31 |
188 ** 11111111 | 11111111 |      address   |
189 **
190 ** Each LOW/HIGH pair describes a disjoint address space region.
191 ** (2 per GSC+ port). Each incoming Runway transaction address is compared
192 ** with both sets of LOW/HIGH registers. If the address is in the range
193 ** greater than or equal to IO_IO_LOW and less than IO_IO_HIGH the transaction
194 ** for forwarded to the respective GSC+ bus.
195 ** Specify IO_IO_LOW equal to or greater than IO_IO_HIGH to avoid specifying
196 ** an address space region.
197 **
198 ** In order for a Runway address to reside within GSC+ extended address space:
199 **	Runway Address [0:7]    must identically compare to 8'b11111111
200 **	Runway Address [8:11]   must be equal to IO_IO_LOW(_HV)[16:19]
201 ** 	Runway Address [12:23]  must be greater than or equal to
202 **	           IO_IO_LOW(_HV)[20:31] and less than IO_IO_HIGH(_HV)[20:31].
203 **	Runway Address [24:39]  is not used in the comparison.
204 **
205 ** When the Runway transaction is forwarded to GSC+, the GSC+ address is
206 ** as follows:
207 **	GSC+ Address[0:3]	4'b1111
208 **	GSC+ Address[4:29]	Runway Address[12:37]
209 **	GSC+ Address[30:31]	2'b00
210 **
211 ** All 4 Low/High registers must be initialized (by PDC) once the lower bus
212 ** is interrogated and address space is defined. The operating system will
213 ** modify the architectural IO_IO_LOW and IO_IO_HIGH registers following
214 ** the PDC initialization.  However, the hardware version dependent IO_IO_LOW
215 ** and IO_IO_HIGH registers should not be subsequently altered by the OS.
216 **
217 ** Writes to both sets of registers will take effect immediately, bypassing
218 ** the queues, which ensures that subsequent Runway transactions are checked
219 ** against the updated bounds values. However reads are queued, introducing
220 ** the possibility of a read being bypassed by a subsequent write to the same
221 ** register. This sequence can be avoided by having software wait for read
222 ** returns before issuing subsequent writes.
223 */
224 
225 struct ioc {
226 	struct ioa_registers __iomem *ioc_regs;  /* I/O MMU base address */
227 	u8  *res_map;	                /* resource map, bit == pdir entry */
228 	u64 *pdir_base;	                /* physical base address */
229 	u32 pdir_size; 			/* bytes, function of IOV Space size */
230 	u32 res_hint;	                /* next available IOVP -
231 					   circular search */
232 	u32 res_size;		    	/* size of resource map in bytes */
233 	spinlock_t res_lock;
234 
235 #ifdef CCIO_COLLECT_STATS
236 #define CCIO_SEARCH_SAMPLE 0x100
237 	unsigned long avg_search[CCIO_SEARCH_SAMPLE];
238 	unsigned long avg_idx;		  /* current index into avg_search */
239 	unsigned long used_pages;
240 	unsigned long msingle_calls;
241 	unsigned long msingle_pages;
242 	unsigned long msg_calls;
243 	unsigned long msg_pages;
244 	unsigned long usingle_calls;
245 	unsigned long usingle_pages;
246 	unsigned long usg_calls;
247 	unsigned long usg_pages;
248 #endif
249 	unsigned short cujo20_bug;
250 
251 	/* STUFF We don't need in performance path */
252 	u32 chainid_shift; 		/* specify bit location of chain_id */
253 	struct ioc *next;		/* Linked list of discovered iocs */
254 	const char *name;		/* device name from firmware */
255 	unsigned int hw_path;           /* the hardware path this ioc is associatd with */
256 	struct pci_dev *fake_pci_dev;   /* the fake pci_dev for non-pci devs */
257 	struct resource mmio_region[2]; /* The "routed" MMIO regions */
258 };
259 
260 static struct ioc *ioc_list;
261 static int ioc_count;
262 
263 /**************************************************************
264 *
265 *   I/O Pdir Resource Management
266 *
267 *   Bits set in the resource map are in use.
268 *   Each bit can represent a number of pages.
269 *   LSbs represent lower addresses (IOVA's).
270 *
271 *   This was was copied from sba_iommu.c. Don't try to unify
272 *   the two resource managers unless a way to have different
273 *   allocation policies is also adjusted. We'd like to avoid
274 *   I/O TLB thrashing by having resource allocation policy
275 *   match the I/O TLB replacement policy.
276 *
277 ***************************************************************/
278 #define IOVP_SIZE PAGE_SIZE
279 #define IOVP_SHIFT PAGE_SHIFT
280 #define IOVP_MASK PAGE_MASK
281 
282 /* Convert from IOVP to IOVA and vice versa. */
283 #define CCIO_IOVA(iovp,offset) ((iovp) | (offset))
284 #define CCIO_IOVP(iova) ((iova) & IOVP_MASK)
285 
286 #define PDIR_INDEX(iovp)    ((iovp)>>IOVP_SHIFT)
287 #define MKIOVP(pdir_idx)    ((long)(pdir_idx) << IOVP_SHIFT)
288 #define MKIOVA(iovp,offset) (dma_addr_t)((long)iovp | (long)offset)
289 
290 /*
291 ** Don't worry about the 150% average search length on a miss.
292 ** If the search wraps around, and passes the res_hint, it will
293 ** cause the kernel to panic anyhow.
294 */
295 #define CCIO_SEARCH_LOOP(ioc, res_idx, mask, size)  \
296        for(; res_ptr < res_end; ++res_ptr) { \
297 		int ret;\
298 		unsigned int idx;\
299 		idx = (unsigned int)((unsigned long)res_ptr - (unsigned long)ioc->res_map); \
300 		ret = iommu_is_span_boundary(idx << 3, pages_needed, 0, boundary_size);\
301 		if ((0 == (*res_ptr & mask)) && !ret) { \
302 			*res_ptr |= mask; \
303 			res_idx = idx;\
304 			ioc->res_hint = res_idx + (size >> 3); \
305 			goto resource_found; \
306 		} \
307 	}
308 
309 #define CCIO_FIND_FREE_MAPPING(ioa, res_idx, mask, size) \
310        u##size *res_ptr = (u##size *)&((ioc)->res_map[ioa->res_hint & ~((size >> 3) - 1)]); \
311        u##size *res_end = (u##size *)&(ioc)->res_map[ioa->res_size]; \
312        CCIO_SEARCH_LOOP(ioc, res_idx, mask, size); \
313        res_ptr = (u##size *)&(ioc)->res_map[0]; \
314        CCIO_SEARCH_LOOP(ioa, res_idx, mask, size);
315 
316 /*
317 ** Find available bit in this ioa's resource map.
318 ** Use a "circular" search:
319 **   o Most IOVA's are "temporary" - avg search time should be small.
320 ** o keep a history of what happened for debugging
321 ** o KISS.
322 **
323 ** Perf optimizations:
324 ** o search for log2(size) bits at a time.
325 ** o search for available resource bits using byte/word/whatever.
326 ** o use different search for "large" (eg > 4 pages) or "very large"
327 **   (eg > 16 pages) mappings.
328 */
329 
330 /**
331  * ccio_alloc_range - Allocate pages in the ioc's resource map.
332  * @ioc: The I/O Controller.
333  * @pages_needed: The requested number of pages 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 = ALIGN((unsigned long long)dma_get_seg_boundary(dev) + 1,
361 			      1ULL << IOVP_SHIFT) >> IOVP_SHIFT;
362 
363 	if (pages_needed <= 8) {
364 		/*
365 		 * LAN traffic will not thrash the TLB IFF the same NIC
366 		 * uses 8 adjacent pages to map separate payload data.
367 		 * ie the same byte in the resource bit map.
368 		 */
369 #if 0
370 		/* FIXME: bit search should shift it's way through
371 		 * an unsigned long - not byte at a time. As it is now,
372 		 * we effectively allocate this byte to this mapping.
373 		 */
374 		unsigned long mask = ~(~0UL >> pages_needed);
375 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, mask, 8);
376 #else
377 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xff, 8);
378 #endif
379 	} else if (pages_needed <= 16) {
380 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xffff, 16);
381 	} else if (pages_needed <= 32) {
382 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~(unsigned int)0, 32);
383 #ifdef __LP64__
384 	} else if (pages_needed <= 64) {
385 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~0UL, 64);
386 #endif
387 	} else {
388 		panic("%s: %s() Too many pages to map. pages_needed: %u\n",
389 		       __FILE__,  __func__, pages_needed);
390 	}
391 
392 	panic("%s: %s() I/O MMU is out of mapping resources.\n", __FILE__,
393 	      __func__);
394 
395 resource_found:
396 
397 	DBG_RES("%s() res_idx %d res_hint: %d\n",
398 		__func__, res_idx, ioc->res_hint);
399 
400 #ifdef CCIO_COLLECT_STATS
401 	{
402 		unsigned long cr_end = mfctl(16);
403 		unsigned long tmp = cr_end - cr_start;
404 		/* check for roll over */
405 		cr_start = (cr_end < cr_start) ?  -(tmp) : (tmp);
406 	}
407 	ioc->avg_search[ioc->avg_idx++] = cr_start;
408 	ioc->avg_idx &= CCIO_SEARCH_SAMPLE - 1;
409 	ioc->used_pages += pages_needed;
410 #endif
411 	/*
412 	** return the bit address.
413 	*/
414 	return res_idx << 3;
415 }
416 
417 #define CCIO_FREE_MAPPINGS(ioc, res_idx, mask, size) \
418         u##size *res_ptr = (u##size *)&((ioc)->res_map[res_idx]); \
419         BUG_ON((*res_ptr & mask) != mask); \
420         *res_ptr &= ~(mask);
421 
422 /**
423  * ccio_free_range - Free pages from the ioc's resource map.
424  * @ioc: The I/O Controller.
425  * @iova: The I/O Virtual Address.
426  * @pages_mapped: The requested number of pages to be freed from the
427  * I/O Pdir.
428  *
429  * This function frees the resouces allocated for the iova.
430  */
431 static void
432 ccio_free_range(struct ioc *ioc, dma_addr_t iova, unsigned long pages_mapped)
433 {
434 	unsigned long iovp = CCIO_IOVP(iova);
435 	unsigned int res_idx = PDIR_INDEX(iovp) >> 3;
436 
437 	BUG_ON(pages_mapped == 0);
438 	BUG_ON((pages_mapped * IOVP_SIZE) > DMA_CHUNK_SIZE);
439 	BUG_ON(pages_mapped > BITS_PER_LONG);
440 
441 	DBG_RES("%s():  res_idx: %d pages_mapped %d\n",
442 		__func__, res_idx, pages_mapped);
443 
444 #ifdef CCIO_COLLECT_STATS
445 	ioc->used_pages -= pages_mapped;
446 #endif
447 
448 	if(pages_mapped <= 8) {
449 #if 0
450 		/* see matching comments in alloc_range */
451 		unsigned long mask = ~(~0UL >> pages_mapped);
452 		CCIO_FREE_MAPPINGS(ioc, res_idx, mask, 8);
453 #else
454 		CCIO_FREE_MAPPINGS(ioc, res_idx, 0xffUL, 8);
455 #endif
456 	} else if(pages_mapped <= 16) {
457 		CCIO_FREE_MAPPINGS(ioc, res_idx, 0xffffUL, 16);
458 	} else if(pages_mapped <= 32) {
459 		CCIO_FREE_MAPPINGS(ioc, res_idx, ~(unsigned int)0, 32);
460 #ifdef __LP64__
461 	} else if(pages_mapped <= 64) {
462 		CCIO_FREE_MAPPINGS(ioc, res_idx, ~0UL, 64);
463 #endif
464 	} else {
465 		panic("%s:%s() Too many pages to unmap.\n", __FILE__,
466 		      __func__);
467 	}
468 }
469 
470 /****************************************************************
471 **
472 **          CCIO dma_ops support routines
473 **
474 *****************************************************************/
475 
476 typedef unsigned long space_t;
477 #define KERNEL_SPACE 0
478 
479 /*
480 ** DMA "Page Type" and Hints
481 ** o if SAFE_DMA isn't set, mapping is for FAST_DMA. SAFE_DMA should be
482 **   set for subcacheline DMA transfers since we don't want to damage the
483 **   other part of a cacheline.
484 ** o SAFE_DMA must be set for "memory" allocated via pci_alloc_consistent().
485 **   This bit tells U2 to do R/M/W for partial cachelines. "Streaming"
486 **   data can avoid this if the mapping covers full cache lines.
487 ** o STOP_MOST is needed for atomicity across cachelines.
488 **   Apparently only "some EISA devices" need this.
489 **   Using CONFIG_ISA is hack. Only the IOA with EISA under it needs
490 **   to use this hint iff the EISA devices needs this feature.
491 **   According to the U2 ERS, STOP_MOST enabled pages hurt performance.
492 ** o PREFETCH should *not* be set for cases like Multiple PCI devices
493 **   behind GSCtoPCI (dino) bus converter. Only one cacheline per GSC
494 **   device can be fetched and multiply DMA streams will thrash the
495 **   prefetch buffer and burn memory bandwidth. See 6.7.3 "Prefetch Rules
496 **   and Invalidation of Prefetch Entries".
497 **
498 ** FIXME: the default hints need to be per GSC device - not global.
499 **
500 ** HP-UX dorks: linux device driver programming model is totally different
501 **    than HP-UX's. HP-UX always sets HINT_PREFETCH since it's drivers
502 **    do special things to work on non-coherent platforms...linux has to
503 **    be much more careful with this.
504 */
505 #define IOPDIR_VALID    0x01UL
506 #define HINT_SAFE_DMA   0x02UL	/* used for pci_alloc_consistent() pages */
507 #ifdef CONFIG_EISA
508 #define HINT_STOP_MOST  0x04UL	/* LSL support */
509 #else
510 #define HINT_STOP_MOST  0x00UL	/* only needed for "some EISA devices" */
511 #endif
512 #define HINT_UDPATE_ENB 0x08UL  /* not used/supported by U2 */
513 #define HINT_PREFETCH   0x10UL	/* for outbound pages which are not SAFE */
514 
515 
516 /*
517 ** Use direction (ie PCI_DMA_TODEVICE) to pick hint.
518 ** ccio_alloc_consistent() depends on this to get SAFE_DMA
519 ** when it passes in BIDIRECTIONAL flag.
520 */
521 static u32 hint_lookup[] = {
522 	[PCI_DMA_BIDIRECTIONAL]	= HINT_STOP_MOST | HINT_SAFE_DMA | IOPDIR_VALID,
523 	[PCI_DMA_TODEVICE]	= HINT_STOP_MOST | HINT_PREFETCH | IOPDIR_VALID,
524 	[PCI_DMA_FROMDEVICE]	= HINT_STOP_MOST | IOPDIR_VALID,
525 };
526 
527 /**
528  * ccio_io_pdir_entry - Initialize an I/O Pdir.
529  * @pdir_ptr: A pointer into I/O Pdir.
530  * @sid: The Space Identifier.
531  * @vba: The virtual address.
532  * @hints: The DMA Hint.
533  *
534  * Given a virtual address (vba, arg2) and space id, (sid, arg1),
535  * load the I/O PDIR entry pointed to by pdir_ptr (arg0). Each IO Pdir
536  * entry consists of 8 bytes as shown below (MSB == bit 0):
537  *
538  *
539  * WORD 0:
540  * +------+----------------+-----------------------------------------------+
541  * | Phys | Virtual Index  |               Phys                            |
542  * | 0:3  |     0:11       |               4:19                            |
543  * |4 bits|   12 bits      |              16 bits                          |
544  * +------+----------------+-----------------------------------------------+
545  * WORD 1:
546  * +-----------------------+-----------------------------------------------+
547  * |      Phys    |  Rsvd  | Prefetch |Update |Rsvd  |Lock  |Safe  |Valid  |
548  * |     20:39    |        | Enable   |Enable |      |Enable|DMA   |       |
549  * |    20 bits   | 5 bits | 1 bit    |1 bit  |2 bits|1 bit |1 bit |1 bit  |
550  * +-----------------------+-----------------------------------------------+
551  *
552  * The virtual index field is filled with the results of the LCI
553  * (Load Coherence Index) instruction.  The 8 bits used for the virtual
554  * index are bits 12:19 of the value returned by LCI.
555  */
556 static void CCIO_INLINE
557 ccio_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
558 		   unsigned long hints)
559 {
560 	register unsigned long pa;
561 	register unsigned long ci; /* coherent index */
562 
563 	/* We currently only support kernel addresses */
564 	BUG_ON(sid != KERNEL_SPACE);
565 
566 	mtsp(sid,1);
567 
568 	/*
569 	** WORD 1 - low order word
570 	** "hints" parm includes the VALID bit!
571 	** "dep" clobbers the physical address offset bits as well.
572 	*/
573 	pa = virt_to_phys(vba);
574 	asm volatile("depw  %1,31,12,%0" : "+r" (pa) : "r" (hints));
575 	((u32 *)pdir_ptr)[1] = (u32) pa;
576 
577 	/*
578 	** WORD 0 - high order word
579 	*/
580 
581 #ifdef __LP64__
582 	/*
583 	** get bits 12:15 of physical address
584 	** shift bits 16:31 of physical address
585 	** and deposit them
586 	*/
587 	asm volatile ("extrd,u %1,15,4,%0" : "=r" (ci) : "r" (pa));
588 	asm volatile ("extrd,u %1,31,16,%0" : "+r" (pa) : "r" (pa));
589 	asm volatile ("depd  %1,35,4,%0" : "+r" (pa) : "r" (ci));
590 #else
591 	pa = 0;
592 #endif
593 	/*
594 	** get CPU coherency index bits
595 	** Grab virtual index [0:11]
596 	** Deposit virt_idx bits into I/O PDIR word
597 	*/
598 	asm volatile ("lci %%r0(%%sr1, %1), %0" : "=r" (ci) : "r" (vba));
599 	asm volatile ("extru %1,19,12,%0" : "+r" (ci) : "r" (ci));
600 	asm volatile ("depw  %1,15,12,%0" : "+r" (pa) : "r" (ci));
601 
602 	((u32 *)pdir_ptr)[0] = (u32) pa;
603 
604 
605 	/* FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
606 	**        PCX-U/U+ do. (eg C200/C240)
607 	**        PCX-T'? Don't know. (eg C110 or similar K-class)
608 	**
609 	** See PDC_MODEL/option 0/SW_CAP word for "Non-coherent IO-PDIR bit".
610 	** Hopefully we can patch (NOP) these out at boot time somehow.
611 	**
612 	** "Since PCX-U employs an offset hash that is incompatible with
613 	** the real mode coherence index generation of U2, the PDIR entry
614 	** must be flushed to memory to retain coherence."
615 	*/
616 	asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
617 	asm volatile("sync");
618 }
619 
620 /**
621  * ccio_clear_io_tlb - Remove stale entries from the I/O TLB.
622  * @ioc: The I/O Controller.
623  * @iovp: The I/O Virtual Page.
624  * @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
625  *
626  * Purge invalid I/O PDIR entries from the I/O TLB.
627  *
628  * FIXME: Can we change the byte_cnt to pages_mapped?
629  */
630 static CCIO_INLINE void
631 ccio_clear_io_tlb(struct ioc *ioc, dma_addr_t iovp, size_t byte_cnt)
632 {
633 	u32 chain_size = 1 << ioc->chainid_shift;
634 
635 	iovp &= IOVP_MASK;	/* clear offset bits, just want pagenum */
636 	byte_cnt += chain_size;
637 
638 	while(byte_cnt > chain_size) {
639 		WRITE_U32(CMD_TLB_PURGE | iovp, &ioc->ioc_regs->io_command);
640 		iovp += chain_size;
641 		byte_cnt -= chain_size;
642 	}
643 }
644 
645 /**
646  * ccio_mark_invalid - Mark the I/O Pdir entries invalid.
647  * @ioc: The I/O Controller.
648  * @iova: The I/O Virtual Address.
649  * @byte_cnt: The requested number of bytes to be freed from the I/O Pdir.
650  *
651  * Mark the I/O Pdir entries invalid and blow away the corresponding I/O
652  * TLB entries.
653  *
654  * FIXME: at some threshold it might be "cheaper" to just blow
655  *        away the entire I/O TLB instead of individual entries.
656  *
657  * FIXME: Uturn has 256 TLB entries. We don't need to purge every
658  *        PDIR entry - just once for each possible TLB entry.
659  *        (We do need to maker I/O PDIR entries invalid regardless).
660  *
661  * FIXME: Can we change byte_cnt to pages_mapped?
662  */
663 static CCIO_INLINE void
664 ccio_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
665 {
666 	u32 iovp = (u32)CCIO_IOVP(iova);
667 	size_t saved_byte_cnt;
668 
669 	/* round up to nearest page size */
670 	saved_byte_cnt = byte_cnt = ALIGN(byte_cnt, IOVP_SIZE);
671 
672 	while(byte_cnt > 0) {
673 		/* invalidate one page at a time */
674 		unsigned int idx = PDIR_INDEX(iovp);
675 		char *pdir_ptr = (char *) &(ioc->pdir_base[idx]);
676 
677 		BUG_ON(idx >= (ioc->pdir_size / sizeof(u64)));
678 		pdir_ptr[7] = 0;	/* clear only VALID bit */
679 		/*
680 		** FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
681 		**   PCX-U/U+ do. (eg C200/C240)
682 		** See PDC_MODEL/option 0/SW_CAP for "Non-coherent IO-PDIR bit".
683 		**
684 		** Hopefully someone figures out how to patch (NOP) the
685 		** FDC/SYNC out at boot time.
686 		*/
687 		asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr[7]));
688 
689 		iovp     += IOVP_SIZE;
690 		byte_cnt -= IOVP_SIZE;
691 	}
692 
693 	asm volatile("sync");
694 	ccio_clear_io_tlb(ioc, CCIO_IOVP(iova), saved_byte_cnt);
695 }
696 
697 /****************************************************************
698 **
699 **          CCIO dma_ops
700 **
701 *****************************************************************/
702 
703 /**
704  * ccio_dma_supported - Verify the IOMMU supports the DMA address range.
705  * @dev: The PCI device.
706  * @mask: A bit mask describing the DMA address range of the device.
707  */
708 static int
709 ccio_dma_supported(struct device *dev, u64 mask)
710 {
711 	if(dev == NULL) {
712 		printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
713 		BUG();
714 		return 0;
715 	}
716 
717 	/* only support 32-bit devices (ie PCI/GSC) */
718 	return (int)(mask == 0xffffffffUL);
719 }
720 
721 /**
722  * ccio_map_single - Map an address range into the IOMMU.
723  * @dev: The PCI device.
724  * @addr: The start address of the DMA region.
725  * @size: The length of the DMA region.
726  * @direction: The direction of the DMA transaction (to/from device).
727  *
728  * This function implements the pci_map_single function.
729  */
730 static dma_addr_t
731 ccio_map_single(struct device *dev, void *addr, size_t size,
732 		enum dma_data_direction direction)
733 {
734 	int idx;
735 	struct ioc *ioc;
736 	unsigned long flags;
737 	dma_addr_t iovp;
738 	dma_addr_t offset;
739 	u64 *pdir_start;
740 	unsigned long hint = hint_lookup[(int)direction];
741 
742 	BUG_ON(!dev);
743 	ioc = GET_IOC(dev);
744 
745 	BUG_ON(size <= 0);
746 
747 	/* save offset bits */
748 	offset = ((unsigned long) addr) & ~IOVP_MASK;
749 
750 	/* round up to nearest IOVP_SIZE */
751 	size = ALIGN(size + offset, IOVP_SIZE);
752 	spin_lock_irqsave(&ioc->res_lock, flags);
753 
754 #ifdef CCIO_COLLECT_STATS
755 	ioc->msingle_calls++;
756 	ioc->msingle_pages += size >> IOVP_SHIFT;
757 #endif
758 
759 	idx = ccio_alloc_range(ioc, dev, size);
760 	iovp = (dma_addr_t)MKIOVP(idx);
761 
762 	pdir_start = &(ioc->pdir_base[idx]);
763 
764 	DBG_RUN("%s() 0x%p -> 0x%lx size: %0x%x\n",
765 		__func__, addr, (long)iovp | offset, size);
766 
767 	/* If not cacheline aligned, force SAFE_DMA on the whole mess */
768 	if((size % L1_CACHE_BYTES) || ((unsigned long)addr % L1_CACHE_BYTES))
769 		hint |= HINT_SAFE_DMA;
770 
771 	while(size > 0) {
772 		ccio_io_pdir_entry(pdir_start, KERNEL_SPACE, (unsigned long)addr, hint);
773 
774 		DBG_RUN(" pdir %p %08x%08x\n",
775 			pdir_start,
776 			(u32) (((u32 *) pdir_start)[0]),
777 			(u32) (((u32 *) pdir_start)[1]));
778 		++pdir_start;
779 		addr += IOVP_SIZE;
780 		size -= IOVP_SIZE;
781 	}
782 
783 	spin_unlock_irqrestore(&ioc->res_lock, flags);
784 
785 	/* form complete address */
786 	return CCIO_IOVA(iovp, offset);
787 }
788 
789 
790 static dma_addr_t
791 ccio_map_page(struct device *dev, struct page *page, unsigned long offset,
792 		size_t size, enum dma_data_direction direction,
793 		unsigned long attrs)
794 {
795 	return ccio_map_single(dev, page_address(page) + offset, size,
796 			direction);
797 }
798 
799 
800 /**
801  * ccio_unmap_page - Unmap an address range from the IOMMU.
802  * @dev: The PCI device.
803  * @addr: The start address of the DMA region.
804  * @size: The length of the DMA region.
805  * @direction: The direction of the DMA transaction (to/from device).
806  */
807 static void
808 ccio_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
809 		enum dma_data_direction direction, unsigned long attrs)
810 {
811 	struct ioc *ioc;
812 	unsigned long flags;
813 	dma_addr_t offset = iova & ~IOVP_MASK;
814 
815 	BUG_ON(!dev);
816 	ioc = GET_IOC(dev);
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  *
843  * This function implements the pci_alloc_consistent function.
844  */
845 static void *
846 ccio_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag,
847 		unsigned long attrs)
848 {
849       void *ret;
850 #if 0
851 /* GRANT Need to establish hierarchy for non-PCI devs as well
852 ** and then provide matching gsc_map_xxx() functions for them as well.
853 */
854 	if(!hwdev) {
855 		/* only support PCI */
856 		*dma_handle = 0;
857 		return 0;
858 	}
859 #endif
860         ret = (void *) __get_free_pages(flag, get_order(size));
861 
862 	if (ret) {
863 		memset(ret, 0, size);
864 		*dma_handle = ccio_map_single(dev, ret, size, PCI_DMA_BIDIRECTIONAL);
865 	}
866 
867 	return ret;
868 }
869 
870 /**
871  * ccio_free - Free a consistent DMA mapping.
872  * @dev: The PCI device.
873  * @size: The length of the DMA region.
874  * @cpu_addr: The cpu address returned from the ccio_alloc_consistent.
875  * @dma_handle: The device address returned from the ccio_alloc_consistent.
876  *
877  * This function implements the pci_free_consistent function.
878  */
879 static void
880 ccio_free(struct device *dev, size_t size, void *cpu_addr,
881 		dma_addr_t dma_handle, unsigned long attrs)
882 {
883 	ccio_unmap_page(dev, dma_handle, size, 0, 0);
884 	free_pages((unsigned long)cpu_addr, get_order(size));
885 }
886 
887 /*
888 ** Since 0 is a valid pdir_base index value, can't use that
889 ** to determine if a value is valid or not. Use a flag to indicate
890 ** the SG list entry contains a valid pdir index.
891 */
892 #define PIDE_FLAG 0x80000000UL
893 
894 #ifdef CCIO_COLLECT_STATS
895 #define IOMMU_MAP_STATS
896 #endif
897 #include "iommu-helpers.h"
898 
899 /**
900  * ccio_map_sg - Map the scatter/gather list into the IOMMU.
901  * @dev: The PCI device.
902  * @sglist: The scatter/gather list to be mapped in the IOMMU.
903  * @nents: The number of entries in the scatter/gather list.
904  * @direction: The direction of the DMA transaction (to/from device).
905  *
906  * This function implements the pci_map_sg function.
907  */
908 static int
909 ccio_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
910 	    enum dma_data_direction direction, unsigned long attrs)
911 {
912 	struct ioc *ioc;
913 	int coalesced, filled = 0;
914 	unsigned long flags;
915 	unsigned long hint = hint_lookup[(int)direction];
916 	unsigned long prev_len = 0, current_len = 0;
917 	int i;
918 
919 	BUG_ON(!dev);
920 	ioc = GET_IOC(dev);
921 
922 	DBG_RUN_SG("%s() START %d entries\n", __func__, nents);
923 
924 	/* Fast path single entry scatterlists. */
925 	if (nents == 1) {
926 		sg_dma_address(sglist) = ccio_map_single(dev,
927 				sg_virt(sglist), sglist->length,
928 				direction);
929 		sg_dma_len(sglist) = sglist->length;
930 		return 1;
931 	}
932 
933 	for(i = 0; i < nents; i++)
934 		prev_len += sglist[i].length;
935 
936 	spin_lock_irqsave(&ioc->res_lock, flags);
937 
938 #ifdef CCIO_COLLECT_STATS
939 	ioc->msg_calls++;
940 #endif
941 
942 	/*
943 	** First coalesce the chunks and allocate I/O pdir space
944 	**
945 	** If this is one DMA stream, we can properly map using the
946 	** correct virtual address associated with each DMA page.
947 	** w/o this association, we wouldn't have coherent DMA!
948 	** Access to the virtual address is what forces a two pass algorithm.
949 	*/
950 	coalesced = iommu_coalesce_chunks(ioc, dev, sglist, nents, ccio_alloc_range);
951 
952 	/*
953 	** Program the I/O Pdir
954 	**
955 	** map the virtual addresses to the I/O Pdir
956 	** o dma_address will contain the pdir index
957 	** o dma_len will contain the number of bytes to map
958 	** o page/offset contain the virtual address.
959 	*/
960 	filled = iommu_fill_pdir(ioc, sglist, nents, hint, ccio_io_pdir_entry);
961 
962 	spin_unlock_irqrestore(&ioc->res_lock, flags);
963 
964 	BUG_ON(coalesced != filled);
965 
966 	DBG_RUN_SG("%s() DONE %d mappings\n", __func__, filled);
967 
968 	for (i = 0; i < filled; i++)
969 		current_len += sg_dma_len(sglist + i);
970 
971 	BUG_ON(current_len != prev_len);
972 
973 	return filled;
974 }
975 
976 /**
977  * ccio_unmap_sg - Unmap the scatter/gather list from the IOMMU.
978  * @dev: The PCI device.
979  * @sglist: The scatter/gather list to be unmapped from the IOMMU.
980  * @nents: The number of entries in the scatter/gather list.
981  * @direction: The direction of the DMA transaction (to/from device).
982  *
983  * This function implements the pci_unmap_sg function.
984  */
985 static void
986 ccio_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
987 	      enum dma_data_direction direction, unsigned long attrs)
988 {
989 	struct ioc *ioc;
990 
991 	BUG_ON(!dev);
992 	ioc = GET_IOC(dev);
993 
994 	DBG_RUN_SG("%s() START %d entries, %p,%x\n",
995 		__func__, nents, sg_virt(sglist), sglist->length);
996 
997 #ifdef CCIO_COLLECT_STATS
998 	ioc->usg_calls++;
999 #endif
1000 
1001 	while(sg_dma_len(sglist) && nents--) {
1002 
1003 #ifdef CCIO_COLLECT_STATS
1004 		ioc->usg_pages += sg_dma_len(sglist) >> PAGE_SHIFT;
1005 #endif
1006 		ccio_unmap_page(dev, sg_dma_address(sglist),
1007 				  sg_dma_len(sglist), direction, 0);
1008 		++sglist;
1009 	}
1010 
1011 	DBG_RUN_SG("%s() DONE (nents %d)\n", __func__, nents);
1012 }
1013 
1014 static struct dma_map_ops ccio_ops = {
1015 	.dma_supported =	ccio_dma_supported,
1016 	.alloc =		ccio_alloc,
1017 	.free =			ccio_free,
1018 	.map_page =		ccio_map_page,
1019 	.unmap_page =		ccio_unmap_page,
1020 	.map_sg = 		ccio_map_sg,
1021 	.unmap_sg = 		ccio_unmap_sg,
1022 };
1023 
1024 #ifdef CONFIG_PROC_FS
1025 static int ccio_proc_info(struct seq_file *m, void *p)
1026 {
1027 	struct ioc *ioc = ioc_list;
1028 
1029 	while (ioc != NULL) {
1030 		unsigned int total_pages = ioc->res_size << 3;
1031 #ifdef CCIO_COLLECT_STATS
1032 		unsigned long avg = 0, min, max;
1033 		int j;
1034 #endif
1035 
1036 		seq_printf(m, "%s\n", ioc->name);
1037 
1038 		seq_printf(m, "Cujo 2.0 bug    : %s\n",
1039 			   (ioc->cujo20_bug ? "yes" : "no"));
1040 
1041 		seq_printf(m, "IO PDIR size    : %d bytes (%d entries)\n",
1042 			   total_pages * 8, total_pages);
1043 
1044 #ifdef CCIO_COLLECT_STATS
1045 		seq_printf(m, "IO PDIR entries : %ld free  %ld used (%d%%)\n",
1046 			   total_pages - ioc->used_pages, ioc->used_pages,
1047 			   (int)(ioc->used_pages * 100 / total_pages));
1048 #endif
1049 
1050 		seq_printf(m, "Resource bitmap : %d bytes (%d pages)\n",
1051 			   ioc->res_size, total_pages);
1052 
1053 #ifdef CCIO_COLLECT_STATS
1054 		min = max = ioc->avg_search[0];
1055 		for(j = 0; j < CCIO_SEARCH_SAMPLE; ++j) {
1056 			avg += ioc->avg_search[j];
1057 			if(ioc->avg_search[j] > max)
1058 				max = ioc->avg_search[j];
1059 			if(ioc->avg_search[j] < min)
1060 				min = ioc->avg_search[j];
1061 		}
1062 		avg /= CCIO_SEARCH_SAMPLE;
1063 		seq_printf(m, "  Bitmap search : %ld/%ld/%ld (min/avg/max CPU Cycles)\n",
1064 			   min, avg, max);
1065 
1066 		seq_printf(m, "pci_map_single(): %8ld calls  %8ld pages (avg %d/1000)\n",
1067 			   ioc->msingle_calls, ioc->msingle_pages,
1068 			   (int)((ioc->msingle_pages * 1000)/ioc->msingle_calls));
1069 
1070 		/* KLUGE - unmap_sg calls unmap_page for each mapped page */
1071 		min = ioc->usingle_calls - ioc->usg_calls;
1072 		max = ioc->usingle_pages - ioc->usg_pages;
1073 		seq_printf(m, "pci_unmap_single: %8ld calls  %8ld pages (avg %d/1000)\n",
1074 			   min, max, (int)((max * 1000)/min));
1075 
1076 		seq_printf(m, "pci_map_sg()    : %8ld calls  %8ld pages (avg %d/1000)\n",
1077 			   ioc->msg_calls, ioc->msg_pages,
1078 			   (int)((ioc->msg_pages * 1000)/ioc->msg_calls));
1079 
1080 		seq_printf(m, "pci_unmap_sg()  : %8ld calls  %8ld pages (avg %d/1000)\n\n\n",
1081 			   ioc->usg_calls, ioc->usg_pages,
1082 			   (int)((ioc->usg_pages * 1000)/ioc->usg_calls));
1083 #endif	/* CCIO_COLLECT_STATS */
1084 
1085 		ioc = ioc->next;
1086 	}
1087 
1088 	return 0;
1089 }
1090 
1091 static int ccio_proc_info_open(struct inode *inode, struct file *file)
1092 {
1093 	return single_open(file, &ccio_proc_info, NULL);
1094 }
1095 
1096 static const struct file_operations ccio_proc_info_fops = {
1097 	.owner = THIS_MODULE,
1098 	.open = ccio_proc_info_open,
1099 	.read = seq_read,
1100 	.llseek = seq_lseek,
1101 	.release = single_release,
1102 };
1103 
1104 static int ccio_proc_bitmap_info(struct seq_file *m, void *p)
1105 {
1106 	struct ioc *ioc = ioc_list;
1107 
1108 	while (ioc != NULL) {
1109 		seq_hex_dump(m, "   ", DUMP_PREFIX_NONE, 32, 4, ioc->res_map,
1110 			     ioc->res_size, false);
1111 		seq_putc(m, '\n');
1112 		ioc = ioc->next;
1113 		break; /* XXX - remove me */
1114 	}
1115 
1116 	return 0;
1117 }
1118 
1119 static int ccio_proc_bitmap_open(struct inode *inode, struct file *file)
1120 {
1121 	return single_open(file, &ccio_proc_bitmap_info, NULL);
1122 }
1123 
1124 static const struct file_operations ccio_proc_bitmap_fops = {
1125 	.owner = THIS_MODULE,
1126 	.open = ccio_proc_bitmap_open,
1127 	.read = seq_read,
1128 	.llseek = seq_lseek,
1129 	.release = single_release,
1130 };
1131 #endif /* CONFIG_PROC_FS */
1132 
1133 /**
1134  * ccio_find_ioc - Find the ioc in the ioc_list
1135  * @hw_path: The hardware path of the ioc.
1136  *
1137  * This function searches the ioc_list for an ioc that matches
1138  * the provide hardware path.
1139  */
1140 static struct ioc * ccio_find_ioc(int hw_path)
1141 {
1142 	int i;
1143 	struct ioc *ioc;
1144 
1145 	ioc = ioc_list;
1146 	for (i = 0; i < ioc_count; i++) {
1147 		if (ioc->hw_path == hw_path)
1148 			return ioc;
1149 
1150 		ioc = ioc->next;
1151 	}
1152 
1153 	return NULL;
1154 }
1155 
1156 /**
1157  * ccio_get_iommu - Find the iommu which controls this device
1158  * @dev: The parisc device.
1159  *
1160  * This function searches through the registered IOMMU's and returns
1161  * the appropriate IOMMU for the device based on its hardware path.
1162  */
1163 void * ccio_get_iommu(const struct parisc_device *dev)
1164 {
1165 	dev = find_pa_parent_type(dev, HPHW_IOA);
1166 	if (!dev)
1167 		return NULL;
1168 
1169 	return ccio_find_ioc(dev->hw_path);
1170 }
1171 
1172 #define CUJO_20_STEP       0x10000000	/* inc upper nibble */
1173 
1174 /* Cujo 2.0 has a bug which will silently corrupt data being transferred
1175  * to/from certain pages.  To avoid this happening, we mark these pages
1176  * as `used', and ensure that nothing will try to allocate from them.
1177  */
1178 void ccio_cujo20_fixup(struct parisc_device *cujo, u32 iovp)
1179 {
1180 	unsigned int idx;
1181 	struct parisc_device *dev = parisc_parent(cujo);
1182 	struct ioc *ioc = ccio_get_iommu(dev);
1183 	u8 *res_ptr;
1184 
1185 	ioc->cujo20_bug = 1;
1186 	res_ptr = ioc->res_map;
1187 	idx = PDIR_INDEX(iovp) >> 3;
1188 
1189 	while (idx < ioc->res_size) {
1190  		res_ptr[idx] |= 0xff;
1191 		idx += PDIR_INDEX(CUJO_20_STEP) >> 3;
1192 	}
1193 }
1194 
1195 #if 0
1196 /* GRANT -  is this needed for U2 or not? */
1197 
1198 /*
1199 ** Get the size of the I/O TLB for this I/O MMU.
1200 **
1201 ** If spa_shift is non-zero (ie probably U2),
1202 ** then calculate the I/O TLB size using spa_shift.
1203 **
1204 ** Otherwise we are supposed to get the IODC entry point ENTRY TLB
1205 ** and execute it. However, both U2 and Uturn firmware supplies spa_shift.
1206 ** I think only Java (K/D/R-class too?) systems don't do this.
1207 */
1208 static int
1209 ccio_get_iotlb_size(struct parisc_device *dev)
1210 {
1211 	if (dev->spa_shift == 0) {
1212 		panic("%s() : Can't determine I/O TLB size.\n", __func__);
1213 	}
1214 	return (1 << dev->spa_shift);
1215 }
1216 #else
1217 
1218 /* Uturn supports 256 TLB entries */
1219 #define CCIO_CHAINID_SHIFT	8
1220 #define CCIO_CHAINID_MASK	0xff
1221 #endif /* 0 */
1222 
1223 /* We *can't* support JAVA (T600). Venture there at your own risk. */
1224 static const struct parisc_device_id ccio_tbl[] = {
1225 	{ HPHW_IOA, HVERSION_REV_ANY_ID, U2_IOA_RUNWAY, 0xb }, /* U2 */
1226 	{ HPHW_IOA, HVERSION_REV_ANY_ID, UTURN_IOA_RUNWAY, 0xb }, /* UTurn */
1227 	{ 0, }
1228 };
1229 
1230 static int ccio_probe(struct parisc_device *dev);
1231 
1232 static struct parisc_driver ccio_driver = {
1233 	.name =		"ccio",
1234 	.id_table =	ccio_tbl,
1235 	.probe =	ccio_probe,
1236 };
1237 
1238 /**
1239  * ccio_ioc_init - Initialize the I/O Controller
1240  * @ioc: The I/O Controller.
1241  *
1242  * Initialize the I/O Controller which includes setting up the
1243  * I/O Page Directory, the resource map, and initalizing the
1244  * U2/Uturn chip into virtual mode.
1245  */
1246 static void
1247 ccio_ioc_init(struct ioc *ioc)
1248 {
1249 	int i;
1250 	unsigned int iov_order;
1251 	u32 iova_space_size;
1252 
1253 	/*
1254 	** Determine IOVA Space size from memory size.
1255 	**
1256 	** Ideally, PCI drivers would register the maximum number
1257 	** of DMA they can have outstanding for each device they
1258 	** own.  Next best thing would be to guess how much DMA
1259 	** can be outstanding based on PCI Class/sub-class. Both
1260 	** methods still require some "extra" to support PCI
1261 	** Hot-Plug/Removal of PCI cards. (aka PCI OLARD).
1262 	*/
1263 
1264 	iova_space_size = (u32) (totalram_pages / count_parisc_driver(&ccio_driver));
1265 
1266 	/* limit IOVA space size to 1MB-1GB */
1267 
1268 	if (iova_space_size < (1 << (20 - PAGE_SHIFT))) {
1269 		iova_space_size =  1 << (20 - PAGE_SHIFT);
1270 #ifdef __LP64__
1271 	} else if (iova_space_size > (1 << (30 - PAGE_SHIFT))) {
1272 		iova_space_size =  1 << (30 - PAGE_SHIFT);
1273 #endif
1274 	}
1275 
1276 	/*
1277 	** iova space must be log2() in size.
1278 	** thus, pdir/res_map will also be log2().
1279 	*/
1280 
1281 	/* We could use larger page sizes in order to *decrease* the number
1282 	** of mappings needed.  (ie 8k pages means 1/2 the mappings).
1283 	**
1284 	** Note: Grant Grunder says "Using 8k I/O pages isn't trivial either
1285 	**   since the pages must also be physically contiguous - typically
1286 	**   this is the case under linux."
1287 	*/
1288 
1289 	iov_order = get_order(iova_space_size << PAGE_SHIFT);
1290 
1291 	/* iova_space_size is now bytes, not pages */
1292 	iova_space_size = 1 << (iov_order + PAGE_SHIFT);
1293 
1294 	ioc->pdir_size = (iova_space_size / IOVP_SIZE) * sizeof(u64);
1295 
1296 	BUG_ON(ioc->pdir_size > 8 * 1024 * 1024);   /* max pdir size <= 8MB */
1297 
1298 	/* Verify it's a power of two */
1299 	BUG_ON((1 << get_order(ioc->pdir_size)) != (ioc->pdir_size >> PAGE_SHIFT));
1300 
1301 	DBG_INIT("%s() hpa 0x%p mem %luMB IOV %dMB (%d bits)\n",
1302 			__func__, ioc->ioc_regs,
1303 			(unsigned long) totalram_pages >> (20 - PAGE_SHIFT),
1304 			iova_space_size>>20,
1305 			iov_order + PAGE_SHIFT);
1306 
1307 	ioc->pdir_base = (u64 *)__get_free_pages(GFP_KERNEL,
1308 						 get_order(ioc->pdir_size));
1309 	if(NULL == ioc->pdir_base) {
1310 		panic("%s() could not allocate I/O Page Table\n", __func__);
1311 	}
1312 	memset(ioc->pdir_base, 0, ioc->pdir_size);
1313 
1314 	BUG_ON((((unsigned long)ioc->pdir_base) & PAGE_MASK) != (unsigned long)ioc->pdir_base);
1315 	DBG_INIT(" base %p\n", ioc->pdir_base);
1316 
1317 	/* resource map size dictated by pdir_size */
1318  	ioc->res_size = (ioc->pdir_size / sizeof(u64)) >> 3;
1319 	DBG_INIT("%s() res_size 0x%x\n", __func__, ioc->res_size);
1320 
1321 	ioc->res_map = (u8 *)__get_free_pages(GFP_KERNEL,
1322 					      get_order(ioc->res_size));
1323 	if(NULL == ioc->res_map) {
1324 		panic("%s() could not allocate resource map\n", __func__);
1325 	}
1326 	memset(ioc->res_map, 0, ioc->res_size);
1327 
1328 	/* Initialize the res_hint to 16 */
1329 	ioc->res_hint = 16;
1330 
1331 	/* Initialize the spinlock */
1332 	spin_lock_init(&ioc->res_lock);
1333 
1334 	/*
1335 	** Chainid is the upper most bits of an IOVP used to determine
1336 	** which TLB entry an IOVP will use.
1337 	*/
1338 	ioc->chainid_shift = get_order(iova_space_size) + PAGE_SHIFT - CCIO_CHAINID_SHIFT;
1339 	DBG_INIT(" chainid_shift 0x%x\n", ioc->chainid_shift);
1340 
1341 	/*
1342 	** Initialize IOA hardware
1343 	*/
1344 	WRITE_U32(CCIO_CHAINID_MASK << ioc->chainid_shift,
1345 		  &ioc->ioc_regs->io_chain_id_mask);
1346 
1347 	WRITE_U32(virt_to_phys(ioc->pdir_base),
1348 		  &ioc->ioc_regs->io_pdir_base);
1349 
1350 	/*
1351 	** Go to "Virtual Mode"
1352 	*/
1353 	WRITE_U32(IOA_NORMAL_MODE, &ioc->ioc_regs->io_control);
1354 
1355 	/*
1356 	** Initialize all I/O TLB entries to 0 (Valid bit off).
1357 	*/
1358 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_m);
1359 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_l);
1360 
1361 	for(i = 1 << CCIO_CHAINID_SHIFT; i ; i--) {
1362 		WRITE_U32((CMD_TLB_DIRECT_WRITE | (i << ioc->chainid_shift)),
1363 			  &ioc->ioc_regs->io_command);
1364 	}
1365 }
1366 
1367 static void __init
1368 ccio_init_resource(struct resource *res, char *name, void __iomem *ioaddr)
1369 {
1370 	int result;
1371 
1372 	res->parent = NULL;
1373 	res->flags = IORESOURCE_MEM;
1374 	/*
1375 	 * bracing ((signed) ...) are required for 64bit kernel because
1376 	 * we only want to sign extend the lower 16 bits of the register.
1377 	 * The upper 16-bits of range registers are hardcoded to 0xffff.
1378 	 */
1379 	res->start = (unsigned long)((signed) READ_U32(ioaddr) << 16);
1380 	res->end = (unsigned long)((signed) (READ_U32(ioaddr + 4) << 16) - 1);
1381 	res->name = name;
1382 	/*
1383 	 * Check if this MMIO range is disable
1384 	 */
1385 	if (res->end + 1 == res->start)
1386 		return;
1387 
1388 	/* On some platforms (e.g. K-Class), we have already registered
1389 	 * resources for devices reported by firmware. Some are children
1390 	 * of ccio.
1391 	 * "insert" ccio ranges in the mmio hierarchy (/proc/iomem).
1392 	 */
1393 	result = insert_resource(&iomem_resource, res);
1394 	if (result < 0) {
1395 		printk(KERN_ERR "%s() failed to claim CCIO bus address space (%08lx,%08lx)\n",
1396 			__func__, (unsigned long)res->start, (unsigned long)res->end);
1397 	}
1398 }
1399 
1400 static void __init ccio_init_resources(struct ioc *ioc)
1401 {
1402 	struct resource *res = ioc->mmio_region;
1403 	char *name = kmalloc(14, GFP_KERNEL);
1404 
1405 	snprintf(name, 14, "GSC Bus [%d/]", ioc->hw_path);
1406 
1407 	ccio_init_resource(res, name, &ioc->ioc_regs->io_io_low);
1408 	ccio_init_resource(res + 1, name, &ioc->ioc_regs->io_io_low_hv);
1409 }
1410 
1411 static int new_ioc_area(struct resource *res, unsigned long size,
1412 		unsigned long min, unsigned long max, unsigned long align)
1413 {
1414 	if (max <= min)
1415 		return -EBUSY;
1416 
1417 	res->start = (max - size + 1) &~ (align - 1);
1418 	res->end = res->start + size;
1419 
1420 	/* We might be trying to expand the MMIO range to include
1421 	 * a child device that has already registered it's MMIO space.
1422 	 * Use "insert" instead of request_resource().
1423 	 */
1424 	if (!insert_resource(&iomem_resource, res))
1425 		return 0;
1426 
1427 	return new_ioc_area(res, size, min, max - size, align);
1428 }
1429 
1430 static int expand_ioc_area(struct resource *res, unsigned long size,
1431 		unsigned long min, unsigned long max, unsigned long align)
1432 {
1433 	unsigned long start, len;
1434 
1435 	if (!res->parent)
1436 		return new_ioc_area(res, size, min, max, align);
1437 
1438 	start = (res->start - size) &~ (align - 1);
1439 	len = res->end - start + 1;
1440 	if (start >= min) {
1441 		if (!adjust_resource(res, start, len))
1442 			return 0;
1443 	}
1444 
1445 	start = res->start;
1446 	len = ((size + res->end + align) &~ (align - 1)) - start;
1447 	if (start + len <= max) {
1448 		if (!adjust_resource(res, start, len))
1449 			return 0;
1450 	}
1451 
1452 	return -EBUSY;
1453 }
1454 
1455 /*
1456  * Dino calls this function.  Beware that we may get called on systems
1457  * which have no IOC (725, B180, C160L, etc) but do have a Dino.
1458  * So it's legal to find no parent IOC.
1459  *
1460  * Some other issues: one of the resources in the ioc may be unassigned.
1461  */
1462 int ccio_allocate_resource(const struct parisc_device *dev,
1463 		struct resource *res, unsigned long size,
1464 		unsigned long min, unsigned long max, unsigned long align)
1465 {
1466 	struct resource *parent = &iomem_resource;
1467 	struct ioc *ioc = ccio_get_iommu(dev);
1468 	if (!ioc)
1469 		goto out;
1470 
1471 	parent = ioc->mmio_region;
1472 	if (parent->parent &&
1473 	    !allocate_resource(parent, res, size, min, max, align, NULL, NULL))
1474 		return 0;
1475 
1476 	if ((parent + 1)->parent &&
1477 	    !allocate_resource(parent + 1, res, size, min, max, align,
1478 				NULL, NULL))
1479 		return 0;
1480 
1481 	if (!expand_ioc_area(parent, size, min, max, align)) {
1482 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1483 			     &ioc->ioc_regs->io_io_low);
1484 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1485 			     &ioc->ioc_regs->io_io_high);
1486 	} else if (!expand_ioc_area(parent + 1, size, min, max, align)) {
1487 		parent++;
1488 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1489 			     &ioc->ioc_regs->io_io_low_hv);
1490 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1491 			     &ioc->ioc_regs->io_io_high_hv);
1492 	} else {
1493 		return -EBUSY;
1494 	}
1495 
1496  out:
1497 	return allocate_resource(parent, res, size, min, max, align, NULL,NULL);
1498 }
1499 
1500 int ccio_request_resource(const struct parisc_device *dev,
1501 		struct resource *res)
1502 {
1503 	struct resource *parent;
1504 	struct ioc *ioc = ccio_get_iommu(dev);
1505 
1506 	if (!ioc) {
1507 		parent = &iomem_resource;
1508 	} else if ((ioc->mmio_region->start <= res->start) &&
1509 			(res->end <= ioc->mmio_region->end)) {
1510 		parent = ioc->mmio_region;
1511 	} else if (((ioc->mmio_region + 1)->start <= res->start) &&
1512 			(res->end <= (ioc->mmio_region + 1)->end)) {
1513 		parent = ioc->mmio_region + 1;
1514 	} else {
1515 		return -EBUSY;
1516 	}
1517 
1518 	/* "transparent" bus bridges need to register MMIO resources
1519 	 * firmware assigned them. e.g. children of hppb.c (e.g. K-class)
1520 	 * registered their resources in the PDC "bus walk" (See
1521 	 * arch/parisc/kernel/inventory.c).
1522 	 */
1523 	return insert_resource(parent, res);
1524 }
1525 
1526 /**
1527  * ccio_probe - Determine if ccio should claim this device.
1528  * @dev: The device which has been found
1529  *
1530  * Determine if ccio should claim this chip (return 0) or not (return 1).
1531  * If so, initialize the chip and tell other partners in crime they
1532  * have work to do.
1533  */
1534 static int __init ccio_probe(struct parisc_device *dev)
1535 {
1536 	int i;
1537 	struct ioc *ioc, **ioc_p = &ioc_list;
1538 
1539 	ioc = kzalloc(sizeof(struct ioc), GFP_KERNEL);
1540 	if (ioc == NULL) {
1541 		printk(KERN_ERR MODULE_NAME ": memory allocation failure\n");
1542 		return 1;
1543 	}
1544 
1545 	ioc->name = dev->id.hversion == U2_IOA_RUNWAY ? "U2" : "UTurn";
1546 
1547 	printk(KERN_INFO "Found %s at 0x%lx\n", ioc->name,
1548 		(unsigned long)dev->hpa.start);
1549 
1550 	for (i = 0; i < ioc_count; i++) {
1551 		ioc_p = &(*ioc_p)->next;
1552 	}
1553 	*ioc_p = ioc;
1554 
1555 	ioc->hw_path = dev->hw_path;
1556 	ioc->ioc_regs = ioremap_nocache(dev->hpa.start, 4096);
1557 	ccio_ioc_init(ioc);
1558 	ccio_init_resources(ioc);
1559 	hppa_dma_ops = &ccio_ops;
1560 	dev->dev.platform_data = kzalloc(sizeof(struct pci_hba_data), GFP_KERNEL);
1561 
1562 	/* if this fails, no I/O cards will work, so may as well bug */
1563 	BUG_ON(dev->dev.platform_data == NULL);
1564 	HBA_DATA(dev->dev.platform_data)->iommu = ioc;
1565 
1566 #ifdef CONFIG_PROC_FS
1567 	if (ioc_count == 0) {
1568 		proc_create(MODULE_NAME, 0, proc_runway_root,
1569 			    &ccio_proc_info_fops);
1570 		proc_create(MODULE_NAME"-bitmap", 0, proc_runway_root,
1571 			    &ccio_proc_bitmap_fops);
1572 	}
1573 #endif
1574 	ioc_count++;
1575 
1576 	parisc_has_iommu();
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