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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/dma-map-ops.h>
43 #include <linux/scatterlist.h>
44 #include <linux/iommu-helper.h>
45 #include <linux/export.h>
46 
47 #include <asm/byteorder.h>
48 #include <asm/cache.h>		/* for L1_CACHE_BYTES */
49 #include <linux/uaccess.h>
50 #include <asm/page.h>
51 #include <asm/dma.h>
52 #include <asm/io.h>
53 #include <asm/hardware.h>       /* for register_module() */
54 #include <asm/parisc-device.h>
55 
56 #include "iommu.h"
57 
58 /*
59 ** Choose "ccio" since that's what HP-UX calls it.
60 ** Make it easier for folks to migrate from one to the other :^)
61 */
62 #define MODULE_NAME "ccio"
63 
64 #undef DEBUG_CCIO_RES
65 #undef DEBUG_CCIO_RUN
66 #undef DEBUG_CCIO_INIT
67 #undef DEBUG_CCIO_RUN_SG
68 
69 #ifdef CONFIG_PROC_FS
70 /* depends on proc fs support. But costs CPU performance. */
71 #undef CCIO_COLLECT_STATS
72 #endif
73 
74 #include <asm/runway.h>		/* for proc_runway_root */
75 
76 #ifdef DEBUG_CCIO_INIT
77 #define DBG_INIT(x...)  printk(x)
78 #else
79 #define DBG_INIT(x...)
80 #endif
81 
82 #ifdef DEBUG_CCIO_RUN
83 #define DBG_RUN(x...)   printk(x)
84 #else
85 #define DBG_RUN(x...)
86 #endif
87 
88 #ifdef DEBUG_CCIO_RES
89 #define DBG_RES(x...)   printk(x)
90 #else
91 #define DBG_RES(x...)
92 #endif
93 
94 #ifdef DEBUG_CCIO_RUN_SG
95 #define DBG_RUN_SG(x...) printk(x)
96 #else
97 #define DBG_RUN_SG(x...)
98 #endif
99 
100 #define 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
ccio_alloc_range(struct ioc * ioc,struct device * dev,size_t size)340 ccio_alloc_range(struct ioc *ioc, struct device *dev, size_t size)
341 {
342 	unsigned int pages_needed = size >> IOVP_SHIFT;
343 	unsigned int res_idx;
344 	unsigned long boundary_size;
345 #ifdef CCIO_COLLECT_STATS
346 	unsigned long cr_start = mfctl(16);
347 #endif
348 
349 	BUG_ON(pages_needed == 0);
350 	BUG_ON((pages_needed * IOVP_SIZE) > DMA_CHUNK_SIZE);
351 
352 	DBG_RES("%s() size: %d pages_needed %d\n",
353 		__func__, size, pages_needed);
354 
355 	/*
356 	** "seek and ye shall find"...praying never hurts either...
357 	** ggg sacrifices another 710 to the computer gods.
358 	*/
359 
360 	boundary_size = dma_get_seg_boundary_nr_pages(dev, IOVP_SHIFT);
361 
362 	if (pages_needed <= 8) {
363 		/*
364 		 * LAN traffic will not thrash the TLB IFF the same NIC
365 		 * uses 8 adjacent pages to map separate payload data.
366 		 * ie the same byte in the resource bit map.
367 		 */
368 #if 0
369 		/* FIXME: bit search should shift it's way through
370 		 * an unsigned long - not byte at a time. As it is now,
371 		 * we effectively allocate this byte to this mapping.
372 		 */
373 		unsigned long mask = ~(~0UL >> pages_needed);
374 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, mask, 8);
375 #else
376 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xff, 8);
377 #endif
378 	} else if (pages_needed <= 16) {
379 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, 0xffff, 16);
380 	} else if (pages_needed <= 32) {
381 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~(unsigned int)0, 32);
382 #ifdef __LP64__
383 	} else if (pages_needed <= 64) {
384 		CCIO_FIND_FREE_MAPPING(ioc, res_idx, ~0UL, 64);
385 #endif
386 	} else {
387 		panic("%s: %s() Too many pages to map. pages_needed: %u\n",
388 		       __FILE__,  __func__, pages_needed);
389 	}
390 
391 	panic("%s: %s() I/O MMU is out of mapping resources.\n", __FILE__,
392 	      __func__);
393 
394 resource_found:
395 
396 	DBG_RES("%s() res_idx %d res_hint: %d\n",
397 		__func__, res_idx, ioc->res_hint);
398 
399 #ifdef CCIO_COLLECT_STATS
400 	{
401 		unsigned long cr_end = mfctl(16);
402 		unsigned long tmp = cr_end - cr_start;
403 		/* check for roll over */
404 		cr_start = (cr_end < cr_start) ?  -(tmp) : (tmp);
405 	}
406 	ioc->avg_search[ioc->avg_idx++] = cr_start;
407 	ioc->avg_idx &= CCIO_SEARCH_SAMPLE - 1;
408 	ioc->used_pages += pages_needed;
409 #endif
410 	/*
411 	** return the bit address.
412 	*/
413 	return res_idx << 3;
414 }
415 
416 #define CCIO_FREE_MAPPINGS(ioc, res_idx, mask, size) \
417         u##size *res_ptr = (u##size *)&((ioc)->res_map[res_idx]); \
418         BUG_ON((*res_ptr & mask) != mask); \
419         *res_ptr &= ~(mask);
420 
421 /**
422  * ccio_free_range - Free pages from the ioc's resource map.
423  * @ioc: The I/O Controller.
424  * @iova: The I/O Virtual Address.
425  * @pages_mapped: The requested number of pages to be freed from the
426  * I/O Pdir.
427  *
428  * This function frees the resouces allocated for the iova.
429  */
430 static void
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 (nents && sg_dma_len(sglist)) {
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 		nents--;
1015 	}
1016 
1017 	DBG_RUN_SG("%s() DONE (nents %d)\n", __func__, nents);
1018 }
1019 
1020 static const struct dma_map_ops ccio_ops = {
1021 	.dma_supported =	ccio_dma_supported,
1022 	.alloc =		ccio_alloc,
1023 	.free =			ccio_free,
1024 	.map_page =		ccio_map_page,
1025 	.unmap_page =		ccio_unmap_page,
1026 	.map_sg = 		ccio_map_sg,
1027 	.unmap_sg = 		ccio_unmap_sg,
1028 	.get_sgtable =		dma_common_get_sgtable,
1029 	.alloc_pages =		dma_common_alloc_pages,
1030 	.free_pages =		dma_common_free_pages,
1031 };
1032 
1033 #ifdef CONFIG_PROC_FS
ccio_proc_info(struct seq_file * m,void * p)1034 static int ccio_proc_info(struct seq_file *m, void *p)
1035 {
1036 	struct ioc *ioc = ioc_list;
1037 
1038 	while (ioc != NULL) {
1039 		unsigned int total_pages = ioc->res_size << 3;
1040 #ifdef CCIO_COLLECT_STATS
1041 		unsigned long avg = 0, min, max;
1042 		int j;
1043 #endif
1044 
1045 		seq_printf(m, "%s\n", ioc->name);
1046 
1047 		seq_printf(m, "Cujo 2.0 bug    : %s\n",
1048 			   (ioc->cujo20_bug ? "yes" : "no"));
1049 
1050 		seq_printf(m, "IO PDIR size    : %d bytes (%d entries)\n",
1051 			   total_pages * 8, total_pages);
1052 
1053 #ifdef CCIO_COLLECT_STATS
1054 		seq_printf(m, "IO PDIR entries : %ld free  %ld used (%d%%)\n",
1055 			   total_pages - ioc->used_pages, ioc->used_pages,
1056 			   (int)(ioc->used_pages * 100 / total_pages));
1057 #endif
1058 
1059 		seq_printf(m, "Resource bitmap : %d bytes (%d pages)\n",
1060 			   ioc->res_size, total_pages);
1061 
1062 #ifdef CCIO_COLLECT_STATS
1063 		min = max = ioc->avg_search[0];
1064 		for(j = 0; j < CCIO_SEARCH_SAMPLE; ++j) {
1065 			avg += ioc->avg_search[j];
1066 			if(ioc->avg_search[j] > max)
1067 				max = ioc->avg_search[j];
1068 			if(ioc->avg_search[j] < min)
1069 				min = ioc->avg_search[j];
1070 		}
1071 		avg /= CCIO_SEARCH_SAMPLE;
1072 		seq_printf(m, "  Bitmap search : %ld/%ld/%ld (min/avg/max CPU Cycles)\n",
1073 			   min, avg, max);
1074 
1075 		seq_printf(m, "pci_map_single(): %8ld calls  %8ld pages (avg %d/1000)\n",
1076 			   ioc->msingle_calls, ioc->msingle_pages,
1077 			   (int)((ioc->msingle_pages * 1000)/ioc->msingle_calls));
1078 
1079 		/* KLUGE - unmap_sg calls unmap_page for each mapped page */
1080 		min = ioc->usingle_calls - ioc->usg_calls;
1081 		max = ioc->usingle_pages - ioc->usg_pages;
1082 		seq_printf(m, "pci_unmap_single: %8ld calls  %8ld pages (avg %d/1000)\n",
1083 			   min, max, (int)((max * 1000)/min));
1084 
1085 		seq_printf(m, "pci_map_sg()    : %8ld calls  %8ld pages (avg %d/1000)\n",
1086 			   ioc->msg_calls, ioc->msg_pages,
1087 			   (int)((ioc->msg_pages * 1000)/ioc->msg_calls));
1088 
1089 		seq_printf(m, "pci_unmap_sg()  : %8ld calls  %8ld pages (avg %d/1000)\n\n\n",
1090 			   ioc->usg_calls, ioc->usg_pages,
1091 			   (int)((ioc->usg_pages * 1000)/ioc->usg_calls));
1092 #endif	/* CCIO_COLLECT_STATS */
1093 
1094 		ioc = ioc->next;
1095 	}
1096 
1097 	return 0;
1098 }
1099 
ccio_proc_bitmap_info(struct seq_file * m,void * p)1100 static int ccio_proc_bitmap_info(struct seq_file *m, void *p)
1101 {
1102 	struct ioc *ioc = ioc_list;
1103 
1104 	while (ioc != NULL) {
1105 		seq_hex_dump(m, "   ", DUMP_PREFIX_NONE, 32, 4, ioc->res_map,
1106 			     ioc->res_size, false);
1107 		seq_putc(m, '\n');
1108 		ioc = ioc->next;
1109 		break; /* XXX - remove me */
1110 	}
1111 
1112 	return 0;
1113 }
1114 #endif /* CONFIG_PROC_FS */
1115 
1116 /**
1117  * ccio_find_ioc - Find the ioc in the ioc_list
1118  * @hw_path: The hardware path of the ioc.
1119  *
1120  * This function searches the ioc_list for an ioc that matches
1121  * the provide hardware path.
1122  */
ccio_find_ioc(int hw_path)1123 static struct ioc * ccio_find_ioc(int hw_path)
1124 {
1125 	int i;
1126 	struct ioc *ioc;
1127 
1128 	ioc = ioc_list;
1129 	for (i = 0; i < ioc_count; i++) {
1130 		if (ioc->hw_path == hw_path)
1131 			return ioc;
1132 
1133 		ioc = ioc->next;
1134 	}
1135 
1136 	return NULL;
1137 }
1138 
1139 /**
1140  * ccio_get_iommu - Find the iommu which controls this device
1141  * @dev: The parisc device.
1142  *
1143  * This function searches through the registered IOMMU's and returns
1144  * the appropriate IOMMU for the device based on its hardware path.
1145  */
ccio_get_iommu(const struct parisc_device * dev)1146 void * ccio_get_iommu(const struct parisc_device *dev)
1147 {
1148 	dev = find_pa_parent_type(dev, HPHW_IOA);
1149 	if (!dev)
1150 		return NULL;
1151 
1152 	return ccio_find_ioc(dev->hw_path);
1153 }
1154 
1155 #define CUJO_20_STEP       0x10000000	/* inc upper nibble */
1156 
1157 /* Cujo 2.0 has a bug which will silently corrupt data being transferred
1158  * to/from certain pages.  To avoid this happening, we mark these pages
1159  * as `used', and ensure that nothing will try to allocate from them.
1160  */
ccio_cujo20_fixup(struct parisc_device * cujo,u32 iovp)1161 void __init ccio_cujo20_fixup(struct parisc_device *cujo, u32 iovp)
1162 {
1163 	unsigned int idx;
1164 	struct parisc_device *dev = parisc_parent(cujo);
1165 	struct ioc *ioc = ccio_get_iommu(dev);
1166 	u8 *res_ptr;
1167 
1168 	ioc->cujo20_bug = 1;
1169 	res_ptr = ioc->res_map;
1170 	idx = PDIR_INDEX(iovp) >> 3;
1171 
1172 	while (idx < ioc->res_size) {
1173  		res_ptr[idx] |= 0xff;
1174 		idx += PDIR_INDEX(CUJO_20_STEP) >> 3;
1175 	}
1176 }
1177 
1178 #if 0
1179 /* GRANT -  is this needed for U2 or not? */
1180 
1181 /*
1182 ** Get the size of the I/O TLB for this I/O MMU.
1183 **
1184 ** If spa_shift is non-zero (ie probably U2),
1185 ** then calculate the I/O TLB size using spa_shift.
1186 **
1187 ** Otherwise we are supposed to get the IODC entry point ENTRY TLB
1188 ** and execute it. However, both U2 and Uturn firmware supplies spa_shift.
1189 ** I think only Java (K/D/R-class too?) systems don't do this.
1190 */
1191 static int
1192 ccio_get_iotlb_size(struct parisc_device *dev)
1193 {
1194 	if (dev->spa_shift == 0) {
1195 		panic("%s() : Can't determine I/O TLB size.\n", __func__);
1196 	}
1197 	return (1 << dev->spa_shift);
1198 }
1199 #else
1200 
1201 /* Uturn supports 256 TLB entries */
1202 #define CCIO_CHAINID_SHIFT	8
1203 #define CCIO_CHAINID_MASK	0xff
1204 #endif /* 0 */
1205 
1206 /* We *can't* support JAVA (T600). Venture there at your own risk. */
1207 static const struct parisc_device_id ccio_tbl[] __initconst = {
1208 	{ HPHW_IOA, HVERSION_REV_ANY_ID, U2_IOA_RUNWAY, 0xb }, /* U2 */
1209 	{ HPHW_IOA, HVERSION_REV_ANY_ID, UTURN_IOA_RUNWAY, 0xb }, /* UTurn */
1210 	{ 0, }
1211 };
1212 
1213 static int ccio_probe(struct parisc_device *dev);
1214 
1215 static struct parisc_driver ccio_driver __refdata = {
1216 	.name =		"ccio",
1217 	.id_table =	ccio_tbl,
1218 	.probe =	ccio_probe,
1219 };
1220 
1221 /**
1222  * ccio_ioc_init - Initialize the I/O Controller
1223  * @ioc: The I/O Controller.
1224  *
1225  * Initialize the I/O Controller which includes setting up the
1226  * I/O Page Directory, the resource map, and initalizing the
1227  * U2/Uturn chip into virtual mode.
1228  */
1229 static void __init
ccio_ioc_init(struct ioc * ioc)1230 ccio_ioc_init(struct ioc *ioc)
1231 {
1232 	int i;
1233 	unsigned int iov_order;
1234 	u32 iova_space_size;
1235 
1236 	/*
1237 	** Determine IOVA Space size from memory size.
1238 	**
1239 	** Ideally, PCI drivers would register the maximum number
1240 	** of DMA they can have outstanding for each device they
1241 	** own.  Next best thing would be to guess how much DMA
1242 	** can be outstanding based on PCI Class/sub-class. Both
1243 	** methods still require some "extra" to support PCI
1244 	** Hot-Plug/Removal of PCI cards. (aka PCI OLARD).
1245 	*/
1246 
1247 	iova_space_size = (u32) (totalram_pages() / count_parisc_driver(&ccio_driver));
1248 
1249 	/* limit IOVA space size to 1MB-1GB */
1250 
1251 	if (iova_space_size < (1 << (20 - PAGE_SHIFT))) {
1252 		iova_space_size =  1 << (20 - PAGE_SHIFT);
1253 #ifdef __LP64__
1254 	} else if (iova_space_size > (1 << (30 - PAGE_SHIFT))) {
1255 		iova_space_size =  1 << (30 - PAGE_SHIFT);
1256 #endif
1257 	}
1258 
1259 	/*
1260 	** iova space must be log2() in size.
1261 	** thus, pdir/res_map will also be log2().
1262 	*/
1263 
1264 	/* We could use larger page sizes in order to *decrease* the number
1265 	** of mappings needed.  (ie 8k pages means 1/2 the mappings).
1266 	**
1267 	** Note: Grant Grunder says "Using 8k I/O pages isn't trivial either
1268 	**   since the pages must also be physically contiguous - typically
1269 	**   this is the case under linux."
1270 	*/
1271 
1272 	iov_order = get_order(iova_space_size << PAGE_SHIFT);
1273 
1274 	/* iova_space_size is now bytes, not pages */
1275 	iova_space_size = 1 << (iov_order + PAGE_SHIFT);
1276 
1277 	ioc->pdir_size = (iova_space_size / IOVP_SIZE) * sizeof(u64);
1278 
1279 	BUG_ON(ioc->pdir_size > 8 * 1024 * 1024);   /* max pdir size <= 8MB */
1280 
1281 	/* Verify it's a power of two */
1282 	BUG_ON((1 << get_order(ioc->pdir_size)) != (ioc->pdir_size >> PAGE_SHIFT));
1283 
1284 	DBG_INIT("%s() hpa 0x%p mem %luMB IOV %dMB (%d bits)\n",
1285 			__func__, ioc->ioc_regs,
1286 			(unsigned long) totalram_pages() >> (20 - PAGE_SHIFT),
1287 			iova_space_size>>20,
1288 			iov_order + PAGE_SHIFT);
1289 
1290 	ioc->pdir_base = (u64 *)__get_free_pages(GFP_KERNEL,
1291 						 get_order(ioc->pdir_size));
1292 	if(NULL == ioc->pdir_base) {
1293 		panic("%s() could not allocate I/O Page Table\n", __func__);
1294 	}
1295 	memset(ioc->pdir_base, 0, ioc->pdir_size);
1296 
1297 	BUG_ON((((unsigned long)ioc->pdir_base) & PAGE_MASK) != (unsigned long)ioc->pdir_base);
1298 	DBG_INIT(" base %p\n", ioc->pdir_base);
1299 
1300 	/* resource map size dictated by pdir_size */
1301  	ioc->res_size = (ioc->pdir_size / sizeof(u64)) >> 3;
1302 	DBG_INIT("%s() res_size 0x%x\n", __func__, ioc->res_size);
1303 
1304 	ioc->res_map = (u8 *)__get_free_pages(GFP_KERNEL,
1305 					      get_order(ioc->res_size));
1306 	if(NULL == ioc->res_map) {
1307 		panic("%s() could not allocate resource map\n", __func__);
1308 	}
1309 	memset(ioc->res_map, 0, ioc->res_size);
1310 
1311 	/* Initialize the res_hint to 16 */
1312 	ioc->res_hint = 16;
1313 
1314 	/* Initialize the spinlock */
1315 	spin_lock_init(&ioc->res_lock);
1316 
1317 	/*
1318 	** Chainid is the upper most bits of an IOVP used to determine
1319 	** which TLB entry an IOVP will use.
1320 	*/
1321 	ioc->chainid_shift = get_order(iova_space_size) + PAGE_SHIFT - CCIO_CHAINID_SHIFT;
1322 	DBG_INIT(" chainid_shift 0x%x\n", ioc->chainid_shift);
1323 
1324 	/*
1325 	** Initialize IOA hardware
1326 	*/
1327 	WRITE_U32(CCIO_CHAINID_MASK << ioc->chainid_shift,
1328 		  &ioc->ioc_regs->io_chain_id_mask);
1329 
1330 	WRITE_U32(virt_to_phys(ioc->pdir_base),
1331 		  &ioc->ioc_regs->io_pdir_base);
1332 
1333 	/*
1334 	** Go to "Virtual Mode"
1335 	*/
1336 	WRITE_U32(IOA_NORMAL_MODE, &ioc->ioc_regs->io_control);
1337 
1338 	/*
1339 	** Initialize all I/O TLB entries to 0 (Valid bit off).
1340 	*/
1341 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_m);
1342 	WRITE_U32(0, &ioc->ioc_regs->io_tlb_entry_l);
1343 
1344 	for(i = 1 << CCIO_CHAINID_SHIFT; i ; i--) {
1345 		WRITE_U32((CMD_TLB_DIRECT_WRITE | (i << ioc->chainid_shift)),
1346 			  &ioc->ioc_regs->io_command);
1347 	}
1348 }
1349 
1350 static void __init
ccio_init_resource(struct resource * res,char * name,void __iomem * ioaddr)1351 ccio_init_resource(struct resource *res, char *name, void __iomem *ioaddr)
1352 {
1353 	int result;
1354 
1355 	res->parent = NULL;
1356 	res->flags = IORESOURCE_MEM;
1357 	/*
1358 	 * bracing ((signed) ...) are required for 64bit kernel because
1359 	 * we only want to sign extend the lower 16 bits of the register.
1360 	 * The upper 16-bits of range registers are hardcoded to 0xffff.
1361 	 */
1362 	res->start = (unsigned long)((signed) READ_U32(ioaddr) << 16);
1363 	res->end = (unsigned long)((signed) (READ_U32(ioaddr + 4) << 16) - 1);
1364 	res->name = name;
1365 	/*
1366 	 * Check if this MMIO range is disable
1367 	 */
1368 	if (res->end + 1 == res->start)
1369 		return;
1370 
1371 	/* On some platforms (e.g. K-Class), we have already registered
1372 	 * resources for devices reported by firmware. Some are children
1373 	 * of ccio.
1374 	 * "insert" ccio ranges in the mmio hierarchy (/proc/iomem).
1375 	 */
1376 	result = insert_resource(&iomem_resource, res);
1377 	if (result < 0) {
1378 		printk(KERN_ERR "%s() failed to claim CCIO bus address space (%08lx,%08lx)\n",
1379 			__func__, (unsigned long)res->start, (unsigned long)res->end);
1380 	}
1381 }
1382 
ccio_init_resources(struct ioc * ioc)1383 static int __init ccio_init_resources(struct ioc *ioc)
1384 {
1385 	struct resource *res = ioc->mmio_region;
1386 	char *name = kmalloc(14, GFP_KERNEL);
1387 	if (unlikely(!name))
1388 		return -ENOMEM;
1389 	snprintf(name, 14, "GSC Bus [%d/]", ioc->hw_path);
1390 
1391 	ccio_init_resource(res, name, &ioc->ioc_regs->io_io_low);
1392 	ccio_init_resource(res + 1, name, &ioc->ioc_regs->io_io_low_hv);
1393 	return 0;
1394 }
1395 
new_ioc_area(struct resource * res,unsigned long size,unsigned long min,unsigned long max,unsigned long align)1396 static int new_ioc_area(struct resource *res, unsigned long size,
1397 		unsigned long min, unsigned long max, unsigned long align)
1398 {
1399 	if (max <= min)
1400 		return -EBUSY;
1401 
1402 	res->start = (max - size + 1) &~ (align - 1);
1403 	res->end = res->start + size;
1404 
1405 	/* We might be trying to expand the MMIO range to include
1406 	 * a child device that has already registered it's MMIO space.
1407 	 * Use "insert" instead of request_resource().
1408 	 */
1409 	if (!insert_resource(&iomem_resource, res))
1410 		return 0;
1411 
1412 	return new_ioc_area(res, size, min, max - size, align);
1413 }
1414 
expand_ioc_area(struct resource * res,unsigned long size,unsigned long min,unsigned long max,unsigned long align)1415 static int expand_ioc_area(struct resource *res, unsigned long size,
1416 		unsigned long min, unsigned long max, unsigned long align)
1417 {
1418 	unsigned long start, len;
1419 
1420 	if (!res->parent)
1421 		return new_ioc_area(res, size, min, max, align);
1422 
1423 	start = (res->start - size) &~ (align - 1);
1424 	len = res->end - start + 1;
1425 	if (start >= min) {
1426 		if (!adjust_resource(res, start, len))
1427 			return 0;
1428 	}
1429 
1430 	start = res->start;
1431 	len = ((size + res->end + align) &~ (align - 1)) - start;
1432 	if (start + len <= max) {
1433 		if (!adjust_resource(res, start, len))
1434 			return 0;
1435 	}
1436 
1437 	return -EBUSY;
1438 }
1439 
1440 /*
1441  * Dino calls this function.  Beware that we may get called on systems
1442  * which have no IOC (725, B180, C160L, etc) but do have a Dino.
1443  * So it's legal to find no parent IOC.
1444  *
1445  * Some other issues: one of the resources in the ioc may be unassigned.
1446  */
ccio_allocate_resource(const struct parisc_device * dev,struct resource * res,unsigned long size,unsigned long min,unsigned long max,unsigned long align)1447 int ccio_allocate_resource(const struct parisc_device *dev,
1448 		struct resource *res, unsigned long size,
1449 		unsigned long min, unsigned long max, unsigned long align)
1450 {
1451 	struct resource *parent = &iomem_resource;
1452 	struct ioc *ioc = ccio_get_iommu(dev);
1453 	if (!ioc)
1454 		goto out;
1455 
1456 	parent = ioc->mmio_region;
1457 	if (parent->parent &&
1458 	    !allocate_resource(parent, res, size, min, max, align, NULL, NULL))
1459 		return 0;
1460 
1461 	if ((parent + 1)->parent &&
1462 	    !allocate_resource(parent + 1, res, size, min, max, align,
1463 				NULL, NULL))
1464 		return 0;
1465 
1466 	if (!expand_ioc_area(parent, size, min, max, align)) {
1467 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1468 			     &ioc->ioc_regs->io_io_low);
1469 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1470 			     &ioc->ioc_regs->io_io_high);
1471 	} else if (!expand_ioc_area(parent + 1, size, min, max, align)) {
1472 		parent++;
1473 		__raw_writel(((parent->start)>>16) | 0xffff0000,
1474 			     &ioc->ioc_regs->io_io_low_hv);
1475 		__raw_writel(((parent->end)>>16) | 0xffff0000,
1476 			     &ioc->ioc_regs->io_io_high_hv);
1477 	} else {
1478 		return -EBUSY;
1479 	}
1480 
1481  out:
1482 	return allocate_resource(parent, res, size, min, max, align, NULL,NULL);
1483 }
1484 
ccio_request_resource(const struct parisc_device * dev,struct resource * res)1485 int ccio_request_resource(const struct parisc_device *dev,
1486 		struct resource *res)
1487 {
1488 	struct resource *parent;
1489 	struct ioc *ioc = ccio_get_iommu(dev);
1490 
1491 	if (!ioc) {
1492 		parent = &iomem_resource;
1493 	} else if ((ioc->mmio_region->start <= res->start) &&
1494 			(res->end <= ioc->mmio_region->end)) {
1495 		parent = ioc->mmio_region;
1496 	} else if (((ioc->mmio_region + 1)->start <= res->start) &&
1497 			(res->end <= (ioc->mmio_region + 1)->end)) {
1498 		parent = ioc->mmio_region + 1;
1499 	} else {
1500 		return -EBUSY;
1501 	}
1502 
1503 	/* "transparent" bus bridges need to register MMIO resources
1504 	 * firmware assigned them. e.g. children of hppb.c (e.g. K-class)
1505 	 * registered their resources in the PDC "bus walk" (See
1506 	 * arch/parisc/kernel/inventory.c).
1507 	 */
1508 	return insert_resource(parent, res);
1509 }
1510 
1511 /**
1512  * ccio_probe - Determine if ccio should claim this device.
1513  * @dev: The device which has been found
1514  *
1515  * Determine if ccio should claim this chip (return 0) or not (return 1).
1516  * If so, initialize the chip and tell other partners in crime they
1517  * have work to do.
1518  */
ccio_probe(struct parisc_device * dev)1519 static int __init ccio_probe(struct parisc_device *dev)
1520 {
1521 	int i;
1522 	struct ioc *ioc, **ioc_p = &ioc_list;
1523 	struct pci_hba_data *hba;
1524 
1525 	ioc = kzalloc(sizeof(struct ioc), GFP_KERNEL);
1526 	if (ioc == NULL) {
1527 		printk(KERN_ERR MODULE_NAME ": memory allocation failure\n");
1528 		return -ENOMEM;
1529 	}
1530 
1531 	ioc->name = dev->id.hversion == U2_IOA_RUNWAY ? "U2" : "UTurn";
1532 
1533 	printk(KERN_INFO "Found %s at 0x%lx\n", ioc->name,
1534 		(unsigned long)dev->hpa.start);
1535 
1536 	for (i = 0; i < ioc_count; i++) {
1537 		ioc_p = &(*ioc_p)->next;
1538 	}
1539 	*ioc_p = ioc;
1540 
1541 	ioc->hw_path = dev->hw_path;
1542 	ioc->ioc_regs = ioremap(dev->hpa.start, 4096);
1543 	if (!ioc->ioc_regs) {
1544 		kfree(ioc);
1545 		return -ENOMEM;
1546 	}
1547 	ccio_ioc_init(ioc);
1548 	if (ccio_init_resources(ioc)) {
1549 		iounmap(ioc->ioc_regs);
1550 		kfree(ioc);
1551 		return -ENOMEM;
1552 	}
1553 	hppa_dma_ops = &ccio_ops;
1554 
1555 	hba = kzalloc(sizeof(*hba), GFP_KERNEL);
1556 	/* if this fails, no I/O cards will work, so may as well bug */
1557 	BUG_ON(hba == NULL);
1558 
1559 	hba->iommu = ioc;
1560 	dev->dev.platform_data = hba;
1561 
1562 #ifdef CONFIG_PROC_FS
1563 	if (ioc_count == 0) {
1564 		proc_create_single(MODULE_NAME, 0, proc_runway_root,
1565 				ccio_proc_info);
1566 		proc_create_single(MODULE_NAME"-bitmap", 0, proc_runway_root,
1567 				ccio_proc_bitmap_info);
1568 	}
1569 #endif
1570 	ioc_count++;
1571 	return 0;
1572 }
1573 
1574 /**
1575  * ccio_init - ccio initialization procedure.
1576  *
1577  * Register this driver.
1578  */
ccio_init(void)1579 void __init ccio_init(void)
1580 {
1581 	register_parisc_driver(&ccio_driver);
1582 }
1583 
1584