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