1/*
2 * Driver for IBM Power 842 compression accelerator
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
17 *
18 * Copyright (C) IBM Corporation, 2012
19 *
20 * Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
21 *          Seth Jennings <sjenning@linux.vnet.ibm.com>
22 */
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/nx842.h>
27#include <linux/of.h>
28#include <linux/slab.h>
29
30#include <asm/page.h>
31#include <asm/vio.h>
32
33#include "nx_csbcpb.h" /* struct nx_csbcpb */
34
35#define MODULE_NAME "nx-compress"
36MODULE_LICENSE("GPL");
37MODULE_AUTHOR("Robert Jennings <rcj@linux.vnet.ibm.com>");
38MODULE_DESCRIPTION("842 H/W Compression driver for IBM Power processors");
39
40#define SHIFT_4K 12
41#define SHIFT_64K 16
42#define SIZE_4K (1UL << SHIFT_4K)
43#define SIZE_64K (1UL << SHIFT_64K)
44
45/* IO buffer must be 128 byte aligned */
46#define IO_BUFFER_ALIGN 128
47
48struct nx842_header {
49	int blocks_nr; /* number of compressed blocks */
50	int offset; /* offset of the first block (from beginning of header) */
51	int sizes[0]; /* size of compressed blocks */
52};
53
54static inline int nx842_header_size(const struct nx842_header *hdr)
55{
56	return sizeof(struct nx842_header) +
57			hdr->blocks_nr * sizeof(hdr->sizes[0]);
58}
59
60/* Macros for fields within nx_csbcpb */
61/* Check the valid bit within the csbcpb valid field */
62#define NX842_CSBCBP_VALID_CHK(x) (x & BIT_MASK(7))
63
64/* CE macros operate on the completion_extension field bits in the csbcpb.
65 * CE0 0=full completion, 1=partial completion
66 * CE1 0=CE0 indicates completion, 1=termination (output may be modified)
67 * CE2 0=processed_bytes is source bytes, 1=processed_bytes is target bytes */
68#define NX842_CSBCPB_CE0(x)	(x & BIT_MASK(7))
69#define NX842_CSBCPB_CE1(x)	(x & BIT_MASK(6))
70#define NX842_CSBCPB_CE2(x)	(x & BIT_MASK(5))
71
72/* The NX unit accepts data only on 4K page boundaries */
73#define NX842_HW_PAGE_SHIFT	SHIFT_4K
74#define NX842_HW_PAGE_SIZE	(ASM_CONST(1) << NX842_HW_PAGE_SHIFT)
75#define NX842_HW_PAGE_MASK	(~(NX842_HW_PAGE_SIZE-1))
76
77enum nx842_status {
78	UNAVAILABLE,
79	AVAILABLE
80};
81
82struct ibm_nx842_counters {
83	atomic64_t comp_complete;
84	atomic64_t comp_failed;
85	atomic64_t decomp_complete;
86	atomic64_t decomp_failed;
87	atomic64_t swdecomp;
88	atomic64_t comp_times[32];
89	atomic64_t decomp_times[32];
90};
91
92static struct nx842_devdata {
93	struct vio_dev *vdev;
94	struct device *dev;
95	struct ibm_nx842_counters *counters;
96	unsigned int max_sg_len;
97	unsigned int max_sync_size;
98	unsigned int max_sync_sg;
99	enum nx842_status status;
100} __rcu *devdata;
101static DEFINE_SPINLOCK(devdata_mutex);
102
103#define NX842_COUNTER_INC(_x) \
104static inline void nx842_inc_##_x( \
105	const struct nx842_devdata *dev) { \
106	if (dev) \
107		atomic64_inc(&dev->counters->_x); \
108}
109NX842_COUNTER_INC(comp_complete);
110NX842_COUNTER_INC(comp_failed);
111NX842_COUNTER_INC(decomp_complete);
112NX842_COUNTER_INC(decomp_failed);
113NX842_COUNTER_INC(swdecomp);
114
115#define NX842_HIST_SLOTS 16
116
117static void ibm_nx842_incr_hist(atomic64_t *times, unsigned int time)
118{
119	int bucket = fls(time);
120
121	if (bucket)
122		bucket = min((NX842_HIST_SLOTS - 1), bucket - 1);
123
124	atomic64_inc(&times[bucket]);
125}
126
127/* NX unit operation flags */
128#define NX842_OP_COMPRESS	0x0
129#define NX842_OP_CRC		0x1
130#define NX842_OP_DECOMPRESS	0x2
131#define NX842_OP_COMPRESS_CRC   (NX842_OP_COMPRESS | NX842_OP_CRC)
132#define NX842_OP_DECOMPRESS_CRC (NX842_OP_DECOMPRESS | NX842_OP_CRC)
133#define NX842_OP_ASYNC		(1<<23)
134#define NX842_OP_NOTIFY		(1<<22)
135#define NX842_OP_NOTIFY_INT(x)	((x & 0xff)<<8)
136
137static unsigned long nx842_get_desired_dma(struct vio_dev *viodev)
138{
139	/* No use of DMA mappings within the driver. */
140	return 0;
141}
142
143struct nx842_slentry {
144	unsigned long ptr; /* Real address (use __pa()) */
145	unsigned long len;
146};
147
148/* pHyp scatterlist entry */
149struct nx842_scatterlist {
150	int entry_nr; /* number of slentries */
151	struct nx842_slentry *entries; /* ptr to array of slentries */
152};
153
154/* Does not include sizeof(entry_nr) in the size */
155static inline unsigned long nx842_get_scatterlist_size(
156				struct nx842_scatterlist *sl)
157{
158	return sl->entry_nr * sizeof(struct nx842_slentry);
159}
160
161static inline unsigned long nx842_get_pa(void *addr)
162{
163	if (is_vmalloc_addr(addr))
164		return page_to_phys(vmalloc_to_page(addr))
165		       + offset_in_page(addr);
166	else
167		return __pa(addr);
168}
169
170static int nx842_build_scatterlist(unsigned long buf, int len,
171			struct nx842_scatterlist *sl)
172{
173	unsigned long nextpage;
174	struct nx842_slentry *entry;
175
176	sl->entry_nr = 0;
177
178	entry = sl->entries;
179	while (len) {
180		entry->ptr = nx842_get_pa((void *)buf);
181		nextpage = ALIGN(buf + 1, NX842_HW_PAGE_SIZE);
182		if (nextpage < buf + len) {
183			/* we aren't at the end yet */
184			if (IS_ALIGNED(buf, NX842_HW_PAGE_SIZE))
185				/* we are in the middle (or beginning) */
186				entry->len = NX842_HW_PAGE_SIZE;
187			else
188				/* we are at the beginning */
189				entry->len = nextpage - buf;
190		} else {
191			/* at the end */
192			entry->len = len;
193		}
194
195		len -= entry->len;
196		buf += entry->len;
197		sl->entry_nr++;
198		entry++;
199	}
200
201	return 0;
202}
203
204/*
205 * Working memory for software decompression
206 */
207struct sw842_fifo {
208	union {
209		char f8[256][8];
210		char f4[512][4];
211	};
212	char f2[256][2];
213	unsigned char f84_full;
214	unsigned char f2_full;
215	unsigned char f8_count;
216	unsigned char f2_count;
217	unsigned int f4_count;
218};
219
220/*
221 * Working memory for crypto API
222 */
223struct nx842_workmem {
224	char bounce[PAGE_SIZE]; /* bounce buffer for decompression input */
225	union {
226		/* hardware working memory */
227		struct {
228			/* scatterlist */
229			char slin[SIZE_4K];
230			char slout[SIZE_4K];
231			/* coprocessor status/parameter block */
232			struct nx_csbcpb csbcpb;
233		};
234		/* software working memory */
235		struct sw842_fifo swfifo; /* software decompression fifo */
236	};
237};
238
239int nx842_get_workmem_size(void)
240{
241	return sizeof(struct nx842_workmem) + NX842_HW_PAGE_SIZE;
242}
243EXPORT_SYMBOL_GPL(nx842_get_workmem_size);
244
245int nx842_get_workmem_size_aligned(void)
246{
247	return sizeof(struct nx842_workmem);
248}
249EXPORT_SYMBOL_GPL(nx842_get_workmem_size_aligned);
250
251static int nx842_validate_result(struct device *dev,
252	struct cop_status_block *csb)
253{
254	/* The csb must be valid after returning from vio_h_cop_sync */
255	if (!NX842_CSBCBP_VALID_CHK(csb->valid)) {
256		dev_err(dev, "%s: cspcbp not valid upon completion.\n",
257				__func__);
258		dev_dbg(dev, "valid:0x%02x cs:0x%02x cc:0x%02x ce:0x%02x\n",
259				csb->valid,
260				csb->crb_seq_number,
261				csb->completion_code,
262				csb->completion_extension);
263		dev_dbg(dev, "processed_bytes:%d address:0x%016lx\n",
264				csb->processed_byte_count,
265				(unsigned long)csb->address);
266		return -EIO;
267	}
268
269	/* Check return values from the hardware in the CSB */
270	switch (csb->completion_code) {
271	case 0:	/* Completed without error */
272		break;
273	case 64: /* Target bytes > Source bytes during compression */
274	case 13: /* Output buffer too small */
275		dev_dbg(dev, "%s: Compression output larger than input\n",
276					__func__);
277		return -ENOSPC;
278	case 66: /* Input data contains an illegal template field */
279	case 67: /* Template indicates data past the end of the input stream */
280		dev_dbg(dev, "%s: Bad data for decompression (code:%d)\n",
281					__func__, csb->completion_code);
282		return -EINVAL;
283	default:
284		dev_dbg(dev, "%s: Unspecified error (code:%d)\n",
285					__func__, csb->completion_code);
286		return -EIO;
287	}
288
289	/* Hardware sanity check */
290	if (!NX842_CSBCPB_CE2(csb->completion_extension)) {
291		dev_err(dev, "%s: No error returned by hardware, but "
292				"data returned is unusable, contact support.\n"
293				"(Additional info: csbcbp->processed bytes "
294				"does not specify processed bytes for the "
295				"target buffer.)\n", __func__);
296		return -EIO;
297	}
298
299	return 0;
300}
301
302/**
303 * nx842_compress - Compress data using the 842 algorithm
304 *
305 * Compression provide by the NX842 coprocessor on IBM Power systems.
306 * The input buffer is compressed and the result is stored in the
307 * provided output buffer.
308 *
309 * Upon return from this function @outlen contains the length of the
310 * compressed data.  If there is an error then @outlen will be 0 and an
311 * error will be specified by the return code from this function.
312 *
313 * @in: Pointer to input buffer, must be page aligned
314 * @inlen: Length of input buffer, must be PAGE_SIZE
315 * @out: Pointer to output buffer
316 * @outlen: Length of output buffer
317 * @wrkmem: ptr to buffer for working memory, size determined by
318 *          nx842_get_workmem_size()
319 *
320 * Returns:
321 *   0		Success, output of length @outlen stored in the buffer at @out
322 *   -ENOMEM	Unable to allocate internal buffers
323 *   -ENOSPC	Output buffer is to small
324 *   -EMSGSIZE	XXX Difficult to describe this limitation
325 *   -EIO	Internal error
326 *   -ENODEV	Hardware unavailable
327 */
328int nx842_compress(const unsigned char *in, unsigned int inlen,
329		       unsigned char *out, unsigned int *outlen, void *wmem)
330{
331	struct nx842_header *hdr;
332	struct nx842_devdata *local_devdata;
333	struct device *dev = NULL;
334	struct nx842_workmem *workmem;
335	struct nx842_scatterlist slin, slout;
336	struct nx_csbcpb *csbcpb;
337	int ret = 0, max_sync_size, i, bytesleft, size, hdrsize;
338	unsigned long inbuf, outbuf, padding;
339	struct vio_pfo_op op = {
340		.done = NULL,
341		.handle = 0,
342		.timeout = 0,
343	};
344	unsigned long start_time = get_tb();
345
346	/*
347	 * Make sure input buffer is 64k page aligned.  This is assumed since
348	 * this driver is designed for page compression only (for now).  This
349	 * is very nice since we can now use direct DDE(s) for the input and
350	 * the alignment is guaranteed.
351	*/
352	inbuf = (unsigned long)in;
353	if (!IS_ALIGNED(inbuf, PAGE_SIZE) || inlen != PAGE_SIZE)
354		return -EINVAL;
355
356	rcu_read_lock();
357	local_devdata = rcu_dereference(devdata);
358	if (!local_devdata || !local_devdata->dev) {
359		rcu_read_unlock();
360		return -ENODEV;
361	}
362	max_sync_size = local_devdata->max_sync_size;
363	dev = local_devdata->dev;
364
365	/* Create the header */
366	hdr = (struct nx842_header *)out;
367	hdr->blocks_nr = PAGE_SIZE / max_sync_size;
368	hdrsize = nx842_header_size(hdr);
369	outbuf = (unsigned long)out + hdrsize;
370	bytesleft = *outlen - hdrsize;
371
372	/* Init scatterlist */
373	workmem = (struct nx842_workmem *)ALIGN((unsigned long)wmem,
374		NX842_HW_PAGE_SIZE);
375	slin.entries = (struct nx842_slentry *)workmem->slin;
376	slout.entries = (struct nx842_slentry *)workmem->slout;
377
378	/* Init operation */
379	op.flags = NX842_OP_COMPRESS;
380	csbcpb = &workmem->csbcpb;
381	memset(csbcpb, 0, sizeof(*csbcpb));
382	op.csbcpb = nx842_get_pa(csbcpb);
383	op.out = nx842_get_pa(slout.entries);
384
385	for (i = 0; i < hdr->blocks_nr; i++) {
386		/*
387		 * Aligning the output blocks to 128 bytes does waste space,
388		 * but it prevents the need for bounce buffers and memory
389		 * copies.  It also simplifies the code a lot.  In the worst
390		 * case (64k page, 4k max_sync_size), you lose up to
391		 * (128*16)/64k = ~3% the compression factor. For 64k
392		 * max_sync_size, the loss would be at most 128/64k = ~0.2%.
393		 */
394		padding = ALIGN(outbuf, IO_BUFFER_ALIGN) - outbuf;
395		outbuf += padding;
396		bytesleft -= padding;
397		if (i == 0)
398			/* save offset into first block in header */
399			hdr->offset = padding + hdrsize;
400
401		if (bytesleft <= 0) {
402			ret = -ENOSPC;
403			goto unlock;
404		}
405
406		/*
407		 * NOTE: If the default max_sync_size is changed from 4k
408		 * to 64k, remove the "likely" case below, since a
409		 * scatterlist will always be needed.
410		 */
411		if (likely(max_sync_size == NX842_HW_PAGE_SIZE)) {
412			/* Create direct DDE */
413			op.in = nx842_get_pa((void *)inbuf);
414			op.inlen = max_sync_size;
415
416		} else {
417			/* Create indirect DDE (scatterlist) */
418			nx842_build_scatterlist(inbuf, max_sync_size, &slin);
419			op.in = nx842_get_pa(slin.entries);
420			op.inlen = -nx842_get_scatterlist_size(&slin);
421		}
422
423		/*
424		 * If max_sync_size != NX842_HW_PAGE_SIZE, an indirect
425		 * DDE is required for the outbuf.
426		 * If max_sync_size == NX842_HW_PAGE_SIZE, outbuf must
427		 * also be page aligned (1 in 128/4k=32 chance) in order
428		 * to use a direct DDE.
429		 * This is unlikely, just use an indirect DDE always.
430		 */
431		nx842_build_scatterlist(outbuf,
432			min(bytesleft, max_sync_size), &slout);
433		/* op.out set before loop */
434		op.outlen = -nx842_get_scatterlist_size(&slout);
435
436		/* Send request to pHyp */
437		ret = vio_h_cop_sync(local_devdata->vdev, &op);
438
439		/* Check for pHyp error */
440		if (ret) {
441			dev_dbg(dev, "%s: vio_h_cop_sync error (ret=%d, hret=%ld)\n",
442				__func__, ret, op.hcall_err);
443			ret = -EIO;
444			goto unlock;
445		}
446
447		/* Check for hardware error */
448		ret = nx842_validate_result(dev, &csbcpb->csb);
449		if (ret && ret != -ENOSPC)
450			goto unlock;
451
452		/* Handle incompressible data */
453		if (unlikely(ret == -ENOSPC)) {
454			if (bytesleft < max_sync_size) {
455				/*
456				 * Not enough space left in the output buffer
457				 * to store uncompressed block
458				 */
459				goto unlock;
460			} else {
461				/* Store incompressible block */
462				memcpy((void *)outbuf, (void *)inbuf,
463					max_sync_size);
464				hdr->sizes[i] = -max_sync_size;
465				outbuf += max_sync_size;
466				bytesleft -= max_sync_size;
467				/* Reset ret, incompressible data handled */
468				ret = 0;
469			}
470		} else {
471			/* Normal case, compression was successful */
472			size = csbcpb->csb.processed_byte_count;
473			dev_dbg(dev, "%s: processed_bytes=%d\n",
474				__func__, size);
475			hdr->sizes[i] = size;
476			outbuf += size;
477			bytesleft -= size;
478		}
479
480		inbuf += max_sync_size;
481	}
482
483	*outlen = (unsigned int)(outbuf - (unsigned long)out);
484
485unlock:
486	if (ret)
487		nx842_inc_comp_failed(local_devdata);
488	else {
489		nx842_inc_comp_complete(local_devdata);
490		ibm_nx842_incr_hist(local_devdata->counters->comp_times,
491			(get_tb() - start_time) / tb_ticks_per_usec);
492	}
493	rcu_read_unlock();
494	return ret;
495}
496EXPORT_SYMBOL_GPL(nx842_compress);
497
498static int sw842_decompress(const unsigned char *, int, unsigned char *, int *,
499			const void *);
500
501/**
502 * nx842_decompress - Decompress data using the 842 algorithm
503 *
504 * Decompression provide by the NX842 coprocessor on IBM Power systems.
505 * The input buffer is decompressed and the result is stored in the
506 * provided output buffer.  The size allocated to the output buffer is
507 * provided by the caller of this function in @outlen.  Upon return from
508 * this function @outlen contains the length of the decompressed data.
509 * If there is an error then @outlen will be 0 and an error will be
510 * specified by the return code from this function.
511 *
512 * @in: Pointer to input buffer, will use bounce buffer if not 128 byte
513 *      aligned
514 * @inlen: Length of input buffer
515 * @out: Pointer to output buffer, must be page aligned
516 * @outlen: Length of output buffer, must be PAGE_SIZE
517 * @wrkmem: ptr to buffer for working memory, size determined by
518 *          nx842_get_workmem_size()
519 *
520 * Returns:
521 *   0		Success, output of length @outlen stored in the buffer at @out
522 *   -ENODEV	Hardware decompression device is unavailable
523 *   -ENOMEM	Unable to allocate internal buffers
524 *   -ENOSPC	Output buffer is to small
525 *   -EINVAL	Bad input data encountered when attempting decompress
526 *   -EIO	Internal error
527 */
528int nx842_decompress(const unsigned char *in, unsigned int inlen,
529			 unsigned char *out, unsigned int *outlen, void *wmem)
530{
531	struct nx842_header *hdr;
532	struct nx842_devdata *local_devdata;
533	struct device *dev = NULL;
534	struct nx842_workmem *workmem;
535	struct nx842_scatterlist slin, slout;
536	struct nx_csbcpb *csbcpb;
537	int ret = 0, i, size, max_sync_size;
538	unsigned long inbuf, outbuf;
539	struct vio_pfo_op op = {
540		.done = NULL,
541		.handle = 0,
542		.timeout = 0,
543	};
544	unsigned long start_time = get_tb();
545
546	/* Ensure page alignment and size */
547	outbuf = (unsigned long)out;
548	if (!IS_ALIGNED(outbuf, PAGE_SIZE) || *outlen != PAGE_SIZE)
549		return -EINVAL;
550
551	rcu_read_lock();
552	local_devdata = rcu_dereference(devdata);
553	if (local_devdata)
554		dev = local_devdata->dev;
555
556	/* Get header */
557	hdr = (struct nx842_header *)in;
558
559	workmem = (struct nx842_workmem *)ALIGN((unsigned long)wmem,
560		NX842_HW_PAGE_SIZE);
561
562	inbuf = (unsigned long)in + hdr->offset;
563	if (likely(!IS_ALIGNED(inbuf, IO_BUFFER_ALIGN))) {
564		/* Copy block(s) into bounce buffer for alignment */
565		memcpy(workmem->bounce, in + hdr->offset, inlen - hdr->offset);
566		inbuf = (unsigned long)workmem->bounce;
567	}
568
569	/* Init scatterlist */
570	slin.entries = (struct nx842_slentry *)workmem->slin;
571	slout.entries = (struct nx842_slentry *)workmem->slout;
572
573	/* Init operation */
574	op.flags = NX842_OP_DECOMPRESS;
575	csbcpb = &workmem->csbcpb;
576	memset(csbcpb, 0, sizeof(*csbcpb));
577	op.csbcpb = nx842_get_pa(csbcpb);
578
579	/*
580	 * max_sync_size may have changed since compression,
581	 * so we can't read it from the device info. We need
582	 * to derive it from hdr->blocks_nr.
583	 */
584	max_sync_size = PAGE_SIZE / hdr->blocks_nr;
585
586	for (i = 0; i < hdr->blocks_nr; i++) {
587		/* Skip padding */
588		inbuf = ALIGN(inbuf, IO_BUFFER_ALIGN);
589
590		if (hdr->sizes[i] < 0) {
591			/* Negative sizes indicate uncompressed data blocks */
592			size = abs(hdr->sizes[i]);
593			memcpy((void *)outbuf, (void *)inbuf, size);
594			outbuf += size;
595			inbuf += size;
596			continue;
597		}
598
599		if (!dev)
600			goto sw;
601
602		/*
603		 * The better the compression, the more likely the "likely"
604		 * case becomes.
605		 */
606		if (likely((inbuf & NX842_HW_PAGE_MASK) ==
607			((inbuf + hdr->sizes[i] - 1) & NX842_HW_PAGE_MASK))) {
608			/* Create direct DDE */
609			op.in = nx842_get_pa((void *)inbuf);
610			op.inlen = hdr->sizes[i];
611		} else {
612			/* Create indirect DDE (scatterlist) */
613			nx842_build_scatterlist(inbuf, hdr->sizes[i] , &slin);
614			op.in = nx842_get_pa(slin.entries);
615			op.inlen = -nx842_get_scatterlist_size(&slin);
616		}
617
618		/*
619		 * NOTE: If the default max_sync_size is changed from 4k
620		 * to 64k, remove the "likely" case below, since a
621		 * scatterlist will always be needed.
622		 */
623		if (likely(max_sync_size == NX842_HW_PAGE_SIZE)) {
624			/* Create direct DDE */
625			op.out = nx842_get_pa((void *)outbuf);
626			op.outlen = max_sync_size;
627		} else {
628			/* Create indirect DDE (scatterlist) */
629			nx842_build_scatterlist(outbuf, max_sync_size, &slout);
630			op.out = nx842_get_pa(slout.entries);
631			op.outlen = -nx842_get_scatterlist_size(&slout);
632		}
633
634		/* Send request to pHyp */
635		ret = vio_h_cop_sync(local_devdata->vdev, &op);
636
637		/* Check for pHyp error */
638		if (ret) {
639			dev_dbg(dev, "%s: vio_h_cop_sync error (ret=%d, hret=%ld)\n",
640				__func__, ret, op.hcall_err);
641			dev = NULL;
642			goto sw;
643		}
644
645		/* Check for hardware error */
646		ret = nx842_validate_result(dev, &csbcpb->csb);
647		if (ret) {
648			dev = NULL;
649			goto sw;
650		}
651
652		/* HW decompression success */
653		inbuf += hdr->sizes[i];
654		outbuf += csbcpb->csb.processed_byte_count;
655		continue;
656
657sw:
658		/* software decompression */
659		size = max_sync_size;
660		ret = sw842_decompress(
661			(unsigned char *)inbuf, hdr->sizes[i],
662			(unsigned char *)outbuf, &size, wmem);
663		if (ret)
664			pr_debug("%s: sw842_decompress failed with %d\n",
665				__func__, ret);
666
667		if (ret) {
668			if (ret != -ENOSPC && ret != -EINVAL &&
669					ret != -EMSGSIZE)
670				ret = -EIO;
671			goto unlock;
672		}
673
674		/* SW decompression success */
675		inbuf += hdr->sizes[i];
676		outbuf += size;
677	}
678
679	*outlen = (unsigned int)(outbuf - (unsigned long)out);
680
681unlock:
682	if (ret)
683		/* decompress fail */
684		nx842_inc_decomp_failed(local_devdata);
685	else {
686		if (!dev)
687			/* software decompress */
688			nx842_inc_swdecomp(local_devdata);
689		nx842_inc_decomp_complete(local_devdata);
690		ibm_nx842_incr_hist(local_devdata->counters->decomp_times,
691			(get_tb() - start_time) / tb_ticks_per_usec);
692	}
693
694	rcu_read_unlock();
695	return ret;
696}
697EXPORT_SYMBOL_GPL(nx842_decompress);
698
699/**
700 * nx842_OF_set_defaults -- Set default (disabled) values for devdata
701 *
702 * @devdata - struct nx842_devdata to update
703 *
704 * Returns:
705 *  0 on success
706 *  -ENOENT if @devdata ptr is NULL
707 */
708static int nx842_OF_set_defaults(struct nx842_devdata *devdata)
709{
710	if (devdata) {
711		devdata->max_sync_size = 0;
712		devdata->max_sync_sg = 0;
713		devdata->max_sg_len = 0;
714		devdata->status = UNAVAILABLE;
715		return 0;
716	} else
717		return -ENOENT;
718}
719
720/**
721 * nx842_OF_upd_status -- Update the device info from OF status prop
722 *
723 * The status property indicates if the accelerator is enabled.  If the
724 * device is in the OF tree it indicates that the hardware is present.
725 * The status field indicates if the device is enabled when the status
726 * is 'okay'.  Otherwise the device driver will be disabled.
727 *
728 * @devdata - struct nx842_devdata to update
729 * @prop - struct property point containing the maxsyncop for the update
730 *
731 * Returns:
732 *  0 - Device is available
733 *  -EINVAL - Device is not available
734 */
735static int nx842_OF_upd_status(struct nx842_devdata *devdata,
736					struct property *prop) {
737	int ret = 0;
738	const char *status = (const char *)prop->value;
739
740	if (!strncmp(status, "okay", (size_t)prop->length)) {
741		devdata->status = AVAILABLE;
742	} else {
743		dev_info(devdata->dev, "%s: status '%s' is not 'okay'\n",
744				__func__, status);
745		devdata->status = UNAVAILABLE;
746	}
747
748	return ret;
749}
750
751/**
752 * nx842_OF_upd_maxsglen -- Update the device info from OF maxsglen prop
753 *
754 * Definition of the 'ibm,max-sg-len' OF property:
755 *  This field indicates the maximum byte length of a scatter list
756 *  for the platform facility. It is a single cell encoded as with encode-int.
757 *
758 * Example:
759 *  # od -x ibm,max-sg-len
760 *  0000000 0000 0ff0
761 *
762 *  In this example, the maximum byte length of a scatter list is
763 *  0x0ff0 (4,080).
764 *
765 * @devdata - struct nx842_devdata to update
766 * @prop - struct property point containing the maxsyncop for the update
767 *
768 * Returns:
769 *  0 on success
770 *  -EINVAL on failure
771 */
772static int nx842_OF_upd_maxsglen(struct nx842_devdata *devdata,
773					struct property *prop) {
774	int ret = 0;
775	const int *maxsglen = prop->value;
776
777	if (prop->length != sizeof(*maxsglen)) {
778		dev_err(devdata->dev, "%s: unexpected format for ibm,max-sg-len property\n", __func__);
779		dev_dbg(devdata->dev, "%s: ibm,max-sg-len is %d bytes long, expected %lu bytes\n", __func__,
780				prop->length, sizeof(*maxsglen));
781		ret = -EINVAL;
782	} else {
783		devdata->max_sg_len = (unsigned int)min(*maxsglen,
784				(int)NX842_HW_PAGE_SIZE);
785	}
786
787	return ret;
788}
789
790/**
791 * nx842_OF_upd_maxsyncop -- Update the device info from OF maxsyncop prop
792 *
793 * Definition of the 'ibm,max-sync-cop' OF property:
794 *  Two series of cells.  The first series of cells represents the maximums
795 *  that can be synchronously compressed. The second series of cells
796 *  represents the maximums that can be synchronously decompressed.
797 *  1. The first cell in each series contains the count of the number of
798 *     data length, scatter list elements pairs that follow – each being
799 *     of the form
800 *    a. One cell data byte length
801 *    b. One cell total number of scatter list elements
802 *
803 * Example:
804 *  # od -x ibm,max-sync-cop
805 *  0000000 0000 0001 0000 1000 0000 01fe 0000 0001
806 *  0000020 0000 1000 0000 01fe
807 *
808 *  In this example, compression supports 0x1000 (4,096) data byte length
809 *  and 0x1fe (510) total scatter list elements.  Decompression supports
810 *  0x1000 (4,096) data byte length and 0x1f3 (510) total scatter list
811 *  elements.
812 *
813 * @devdata - struct nx842_devdata to update
814 * @prop - struct property point containing the maxsyncop for the update
815 *
816 * Returns:
817 *  0 on success
818 *  -EINVAL on failure
819 */
820static int nx842_OF_upd_maxsyncop(struct nx842_devdata *devdata,
821					struct property *prop) {
822	int ret = 0;
823	const struct maxsynccop_t {
824		int comp_elements;
825		int comp_data_limit;
826		int comp_sg_limit;
827		int decomp_elements;
828		int decomp_data_limit;
829		int decomp_sg_limit;
830	} *maxsynccop;
831
832	if (prop->length != sizeof(*maxsynccop)) {
833		dev_err(devdata->dev, "%s: unexpected format for ibm,max-sync-cop property\n", __func__);
834		dev_dbg(devdata->dev, "%s: ibm,max-sync-cop is %d bytes long, expected %lu bytes\n", __func__, prop->length,
835				sizeof(*maxsynccop));
836		ret = -EINVAL;
837		goto out;
838	}
839
840	maxsynccop = (const struct maxsynccop_t *)prop->value;
841
842	/* Use one limit rather than separate limits for compression and
843	 * decompression. Set a maximum for this so as not to exceed the
844	 * size that the header can support and round the value down to
845	 * the hardware page size (4K) */
846	devdata->max_sync_size =
847			(unsigned int)min(maxsynccop->comp_data_limit,
848					maxsynccop->decomp_data_limit);
849
850	devdata->max_sync_size = min_t(unsigned int, devdata->max_sync_size,
851					SIZE_64K);
852
853	if (devdata->max_sync_size < SIZE_4K) {
854		dev_err(devdata->dev, "%s: hardware max data size (%u) is "
855				"less than the driver minimum, unable to use "
856				"the hardware device\n",
857				__func__, devdata->max_sync_size);
858		ret = -EINVAL;
859		goto out;
860	}
861
862	devdata->max_sync_sg = (unsigned int)min(maxsynccop->comp_sg_limit,
863						maxsynccop->decomp_sg_limit);
864	if (devdata->max_sync_sg < 1) {
865		dev_err(devdata->dev, "%s: hardware max sg size (%u) is "
866				"less than the driver minimum, unable to use "
867				"the hardware device\n",
868				__func__, devdata->max_sync_sg);
869		ret = -EINVAL;
870		goto out;
871	}
872
873out:
874	return ret;
875}
876
877/**
878 *
879 * nx842_OF_upd -- Handle OF properties updates for the device.
880 *
881 * Set all properties from the OF tree.  Optionally, a new property
882 * can be provided by the @new_prop pointer to overwrite an existing value.
883 * The device will remain disabled until all values are valid, this function
884 * will return an error for updates unless all values are valid.
885 *
886 * @new_prop: If not NULL, this property is being updated.  If NULL, update
887 *  all properties from the current values in the OF tree.
888 *
889 * Returns:
890 *  0 - Success
891 *  -ENOMEM - Could not allocate memory for new devdata structure
892 *  -EINVAL - property value not found, new_prop is not a recognized
893 *	property for the device or property value is not valid.
894 *  -ENODEV - Device is not available
895 */
896static int nx842_OF_upd(struct property *new_prop)
897{
898	struct nx842_devdata *old_devdata = NULL;
899	struct nx842_devdata *new_devdata = NULL;
900	struct device_node *of_node = NULL;
901	struct property *status = NULL;
902	struct property *maxsglen = NULL;
903	struct property *maxsyncop = NULL;
904	int ret = 0;
905	unsigned long flags;
906
907	spin_lock_irqsave(&devdata_mutex, flags);
908	old_devdata = rcu_dereference_check(devdata,
909			lockdep_is_held(&devdata_mutex));
910	if (old_devdata)
911		of_node = old_devdata->dev->of_node;
912
913	if (!old_devdata || !of_node) {
914		pr_err("%s: device is not available\n", __func__);
915		spin_unlock_irqrestore(&devdata_mutex, flags);
916		return -ENODEV;
917	}
918
919	new_devdata = kzalloc(sizeof(*new_devdata), GFP_NOFS);
920	if (!new_devdata) {
921		dev_err(old_devdata->dev, "%s: Could not allocate memory for device data\n", __func__);
922		ret = -ENOMEM;
923		goto error_out;
924	}
925
926	memcpy(new_devdata, old_devdata, sizeof(*old_devdata));
927	new_devdata->counters = old_devdata->counters;
928
929	/* Set ptrs for existing properties */
930	status = of_find_property(of_node, "status", NULL);
931	maxsglen = of_find_property(of_node, "ibm,max-sg-len", NULL);
932	maxsyncop = of_find_property(of_node, "ibm,max-sync-cop", NULL);
933	if (!status || !maxsglen || !maxsyncop) {
934		dev_err(old_devdata->dev, "%s: Could not locate device properties\n", __func__);
935		ret = -EINVAL;
936		goto error_out;
937	}
938
939	/*
940	 * If this is a property update, there are only certain properties that
941	 * we care about. Bail if it isn't in the below list
942	 */
943	if (new_prop && (strncmp(new_prop->name, "status", new_prop->length) ||
944		         strncmp(new_prop->name, "ibm,max-sg-len", new_prop->length) ||
945		         strncmp(new_prop->name, "ibm,max-sync-cop", new_prop->length)))
946		goto out;
947
948	/* Perform property updates */
949	ret = nx842_OF_upd_status(new_devdata, status);
950	if (ret)
951		goto error_out;
952
953	ret = nx842_OF_upd_maxsglen(new_devdata, maxsglen);
954	if (ret)
955		goto error_out;
956
957	ret = nx842_OF_upd_maxsyncop(new_devdata, maxsyncop);
958	if (ret)
959		goto error_out;
960
961out:
962	dev_info(old_devdata->dev, "%s: max_sync_size new:%u old:%u\n",
963			__func__, new_devdata->max_sync_size,
964			old_devdata->max_sync_size);
965	dev_info(old_devdata->dev, "%s: max_sync_sg new:%u old:%u\n",
966			__func__, new_devdata->max_sync_sg,
967			old_devdata->max_sync_sg);
968	dev_info(old_devdata->dev, "%s: max_sg_len new:%u old:%u\n",
969			__func__, new_devdata->max_sg_len,
970			old_devdata->max_sg_len);
971
972	rcu_assign_pointer(devdata, new_devdata);
973	spin_unlock_irqrestore(&devdata_mutex, flags);
974	synchronize_rcu();
975	dev_set_drvdata(new_devdata->dev, new_devdata);
976	kfree(old_devdata);
977	return 0;
978
979error_out:
980	if (new_devdata) {
981		dev_info(old_devdata->dev, "%s: device disabled\n", __func__);
982		nx842_OF_set_defaults(new_devdata);
983		rcu_assign_pointer(devdata, new_devdata);
984		spin_unlock_irqrestore(&devdata_mutex, flags);
985		synchronize_rcu();
986		dev_set_drvdata(new_devdata->dev, new_devdata);
987		kfree(old_devdata);
988	} else {
989		dev_err(old_devdata->dev, "%s: could not update driver from hardware\n", __func__);
990		spin_unlock_irqrestore(&devdata_mutex, flags);
991	}
992
993	if (!ret)
994		ret = -EINVAL;
995	return ret;
996}
997
998/**
999 * nx842_OF_notifier - Process updates to OF properties for the device
1000 *
1001 * @np: notifier block
1002 * @action: notifier action
1003 * @update: struct pSeries_reconfig_prop_update pointer if action is
1004 *	PSERIES_UPDATE_PROPERTY
1005 *
1006 * Returns:
1007 *	NOTIFY_OK on success
1008 *	NOTIFY_BAD encoded with error number on failure, use
1009 *		notifier_to_errno() to decode this value
1010 */
1011static int nx842_OF_notifier(struct notifier_block *np, unsigned long action,
1012			     void *data)
1013{
1014	struct of_reconfig_data *upd = data;
1015	struct nx842_devdata *local_devdata;
1016	struct device_node *node = NULL;
1017
1018	rcu_read_lock();
1019	local_devdata = rcu_dereference(devdata);
1020	if (local_devdata)
1021		node = local_devdata->dev->of_node;
1022
1023	if (local_devdata &&
1024			action == OF_RECONFIG_UPDATE_PROPERTY &&
1025			!strcmp(upd->dn->name, node->name)) {
1026		rcu_read_unlock();
1027		nx842_OF_upd(upd->prop);
1028	} else
1029		rcu_read_unlock();
1030
1031	return NOTIFY_OK;
1032}
1033
1034static struct notifier_block nx842_of_nb = {
1035	.notifier_call = nx842_OF_notifier,
1036};
1037
1038#define nx842_counter_read(_name)					\
1039static ssize_t nx842_##_name##_show(struct device *dev,		\
1040		struct device_attribute *attr,				\
1041		char *buf) {						\
1042	struct nx842_devdata *local_devdata;			\
1043	int p = 0;							\
1044	rcu_read_lock();						\
1045	local_devdata = rcu_dereference(devdata);			\
1046	if (local_devdata)						\
1047		p = snprintf(buf, PAGE_SIZE, "%ld\n",			\
1048		       atomic64_read(&local_devdata->counters->_name));	\
1049	rcu_read_unlock();						\
1050	return p;							\
1051}
1052
1053#define NX842DEV_COUNTER_ATTR_RO(_name)					\
1054	nx842_counter_read(_name);					\
1055	static struct device_attribute dev_attr_##_name = __ATTR(_name,	\
1056						0444,			\
1057						nx842_##_name##_show,\
1058						NULL);
1059
1060NX842DEV_COUNTER_ATTR_RO(comp_complete);
1061NX842DEV_COUNTER_ATTR_RO(comp_failed);
1062NX842DEV_COUNTER_ATTR_RO(decomp_complete);
1063NX842DEV_COUNTER_ATTR_RO(decomp_failed);
1064NX842DEV_COUNTER_ATTR_RO(swdecomp);
1065
1066static ssize_t nx842_timehist_show(struct device *,
1067		struct device_attribute *, char *);
1068
1069static struct device_attribute dev_attr_comp_times = __ATTR(comp_times, 0444,
1070		nx842_timehist_show, NULL);
1071static struct device_attribute dev_attr_decomp_times = __ATTR(decomp_times,
1072		0444, nx842_timehist_show, NULL);
1073
1074static ssize_t nx842_timehist_show(struct device *dev,
1075		struct device_attribute *attr, char *buf) {
1076	char *p = buf;
1077	struct nx842_devdata *local_devdata;
1078	atomic64_t *times;
1079	int bytes_remain = PAGE_SIZE;
1080	int bytes;
1081	int i;
1082
1083	rcu_read_lock();
1084	local_devdata = rcu_dereference(devdata);
1085	if (!local_devdata) {
1086		rcu_read_unlock();
1087		return 0;
1088	}
1089
1090	if (attr == &dev_attr_comp_times)
1091		times = local_devdata->counters->comp_times;
1092	else if (attr == &dev_attr_decomp_times)
1093		times = local_devdata->counters->decomp_times;
1094	else {
1095		rcu_read_unlock();
1096		return 0;
1097	}
1098
1099	for (i = 0; i < (NX842_HIST_SLOTS - 2); i++) {
1100		bytes = snprintf(p, bytes_remain, "%u-%uus:\t%ld\n",
1101			       i ? (2<<(i-1)) : 0, (2<<i)-1,
1102			       atomic64_read(&times[i]));
1103		bytes_remain -= bytes;
1104		p += bytes;
1105	}
1106	/* The last bucket holds everything over
1107	 * 2<<(NX842_HIST_SLOTS - 2) us */
1108	bytes = snprintf(p, bytes_remain, "%uus - :\t%ld\n",
1109			2<<(NX842_HIST_SLOTS - 2),
1110			atomic64_read(&times[(NX842_HIST_SLOTS - 1)]));
1111	p += bytes;
1112
1113	rcu_read_unlock();
1114	return p - buf;
1115}
1116
1117static struct attribute *nx842_sysfs_entries[] = {
1118	&dev_attr_comp_complete.attr,
1119	&dev_attr_comp_failed.attr,
1120	&dev_attr_decomp_complete.attr,
1121	&dev_attr_decomp_failed.attr,
1122	&dev_attr_swdecomp.attr,
1123	&dev_attr_comp_times.attr,
1124	&dev_attr_decomp_times.attr,
1125	NULL,
1126};
1127
1128static struct attribute_group nx842_attribute_group = {
1129	.name = NULL,		/* put in device directory */
1130	.attrs = nx842_sysfs_entries,
1131};
1132
1133static int __init nx842_probe(struct vio_dev *viodev,
1134				  const struct vio_device_id *id)
1135{
1136	struct nx842_devdata *old_devdata, *new_devdata = NULL;
1137	unsigned long flags;
1138	int ret = 0;
1139
1140	spin_lock_irqsave(&devdata_mutex, flags);
1141	old_devdata = rcu_dereference_check(devdata,
1142			lockdep_is_held(&devdata_mutex));
1143
1144	if (old_devdata && old_devdata->vdev != NULL) {
1145		dev_err(&viodev->dev, "%s: Attempt to register more than one instance of the hardware\n", __func__);
1146		ret = -1;
1147		goto error_unlock;
1148	}
1149
1150	dev_set_drvdata(&viodev->dev, NULL);
1151
1152	new_devdata = kzalloc(sizeof(*new_devdata), GFP_NOFS);
1153	if (!new_devdata) {
1154		dev_err(&viodev->dev, "%s: Could not allocate memory for device data\n", __func__);
1155		ret = -ENOMEM;
1156		goto error_unlock;
1157	}
1158
1159	new_devdata->counters = kzalloc(sizeof(*new_devdata->counters),
1160			GFP_NOFS);
1161	if (!new_devdata->counters) {
1162		dev_err(&viodev->dev, "%s: Could not allocate memory for performance counters\n", __func__);
1163		ret = -ENOMEM;
1164		goto error_unlock;
1165	}
1166
1167	new_devdata->vdev = viodev;
1168	new_devdata->dev = &viodev->dev;
1169	nx842_OF_set_defaults(new_devdata);
1170
1171	rcu_assign_pointer(devdata, new_devdata);
1172	spin_unlock_irqrestore(&devdata_mutex, flags);
1173	synchronize_rcu();
1174	kfree(old_devdata);
1175
1176	of_reconfig_notifier_register(&nx842_of_nb);
1177
1178	ret = nx842_OF_upd(NULL);
1179	if (ret && ret != -ENODEV) {
1180		dev_err(&viodev->dev, "could not parse device tree. %d\n", ret);
1181		ret = -1;
1182		goto error;
1183	}
1184
1185	rcu_read_lock();
1186	dev_set_drvdata(&viodev->dev, rcu_dereference(devdata));
1187	rcu_read_unlock();
1188
1189	if (sysfs_create_group(&viodev->dev.kobj, &nx842_attribute_group)) {
1190		dev_err(&viodev->dev, "could not create sysfs device attributes\n");
1191		ret = -1;
1192		goto error;
1193	}
1194
1195	return 0;
1196
1197error_unlock:
1198	spin_unlock_irqrestore(&devdata_mutex, flags);
1199	if (new_devdata)
1200		kfree(new_devdata->counters);
1201	kfree(new_devdata);
1202error:
1203	return ret;
1204}
1205
1206static int __exit nx842_remove(struct vio_dev *viodev)
1207{
1208	struct nx842_devdata *old_devdata;
1209	unsigned long flags;
1210
1211	pr_info("Removing IBM Power 842 compression device\n");
1212	sysfs_remove_group(&viodev->dev.kobj, &nx842_attribute_group);
1213
1214	spin_lock_irqsave(&devdata_mutex, flags);
1215	old_devdata = rcu_dereference_check(devdata,
1216			lockdep_is_held(&devdata_mutex));
1217	of_reconfig_notifier_unregister(&nx842_of_nb);
1218	RCU_INIT_POINTER(devdata, NULL);
1219	spin_unlock_irqrestore(&devdata_mutex, flags);
1220	synchronize_rcu();
1221	dev_set_drvdata(&viodev->dev, NULL);
1222	if (old_devdata)
1223		kfree(old_devdata->counters);
1224	kfree(old_devdata);
1225	return 0;
1226}
1227
1228static struct vio_device_id nx842_driver_ids[] = {
1229	{"ibm,compression-v1", "ibm,compression"},
1230	{"", ""},
1231};
1232
1233static struct vio_driver nx842_driver = {
1234	.name = MODULE_NAME,
1235	.probe = nx842_probe,
1236	.remove = __exit_p(nx842_remove),
1237	.get_desired_dma = nx842_get_desired_dma,
1238	.id_table = nx842_driver_ids,
1239};
1240
1241static int __init nx842_init(void)
1242{
1243	struct nx842_devdata *new_devdata;
1244	pr_info("Registering IBM Power 842 compression driver\n");
1245
1246	RCU_INIT_POINTER(devdata, NULL);
1247	new_devdata = kzalloc(sizeof(*new_devdata), GFP_KERNEL);
1248	if (!new_devdata) {
1249		pr_err("Could not allocate memory for device data\n");
1250		return -ENOMEM;
1251	}
1252	new_devdata->status = UNAVAILABLE;
1253	RCU_INIT_POINTER(devdata, new_devdata);
1254
1255	return vio_register_driver(&nx842_driver);
1256}
1257
1258module_init(nx842_init);
1259
1260static void __exit nx842_exit(void)
1261{
1262	struct nx842_devdata *old_devdata;
1263	unsigned long flags;
1264
1265	pr_info("Exiting IBM Power 842 compression driver\n");
1266	spin_lock_irqsave(&devdata_mutex, flags);
1267	old_devdata = rcu_dereference_check(devdata,
1268			lockdep_is_held(&devdata_mutex));
1269	RCU_INIT_POINTER(devdata, NULL);
1270	spin_unlock_irqrestore(&devdata_mutex, flags);
1271	synchronize_rcu();
1272	if (old_devdata)
1273		dev_set_drvdata(old_devdata->dev, NULL);
1274	kfree(old_devdata);
1275	vio_unregister_driver(&nx842_driver);
1276}
1277
1278module_exit(nx842_exit);
1279
1280/*********************************
1281 * 842 software decompressor
1282*********************************/
1283typedef int (*sw842_template_op)(const char **, int *, unsigned char **,
1284						struct sw842_fifo *);
1285
1286static int sw842_data8(const char **, int *, unsigned char **,
1287						struct sw842_fifo *);
1288static int sw842_data4(const char **, int *, unsigned char **,
1289						struct sw842_fifo *);
1290static int sw842_data2(const char **, int *, unsigned char **,
1291						struct sw842_fifo *);
1292static int sw842_ptr8(const char **, int *, unsigned char **,
1293						struct sw842_fifo *);
1294static int sw842_ptr4(const char **, int *, unsigned char **,
1295						struct sw842_fifo *);
1296static int sw842_ptr2(const char **, int *, unsigned char **,
1297						struct sw842_fifo *);
1298
1299/* special templates */
1300#define SW842_TMPL_REPEAT 0x1B
1301#define SW842_TMPL_ZEROS 0x1C
1302#define SW842_TMPL_EOF 0x1E
1303
1304static sw842_template_op sw842_tmpl_ops[26][4] = {
1305	{ sw842_data8, NULL}, /* 0 (00000) */
1306	{ sw842_data4, sw842_data2, sw842_ptr2,  NULL},
1307	{ sw842_data4, sw842_ptr2,  sw842_data2, NULL},
1308	{ sw842_data4, sw842_ptr2,  sw842_ptr2,  NULL},
1309	{ sw842_data4, sw842_ptr4,  NULL},
1310	{ sw842_data2, sw842_ptr2,  sw842_data4, NULL},
1311	{ sw842_data2, sw842_ptr2,  sw842_data2, sw842_ptr2},
1312	{ sw842_data2, sw842_ptr2,  sw842_ptr2,  sw842_data2},
1313	{ sw842_data2, sw842_ptr2,  sw842_ptr2,  sw842_ptr2,},
1314	{ sw842_data2, sw842_ptr2,  sw842_ptr4,  NULL},
1315	{ sw842_ptr2,  sw842_data2, sw842_data4, NULL}, /* 10 (01010) */
1316	{ sw842_ptr2,  sw842_data4, sw842_ptr2,  NULL},
1317	{ sw842_ptr2,  sw842_data2, sw842_ptr2,  sw842_data2},
1318	{ sw842_ptr2,  sw842_data2, sw842_ptr2,  sw842_ptr2},
1319	{ sw842_ptr2,  sw842_data2, sw842_ptr4,  NULL},
1320	{ sw842_ptr2,  sw842_ptr2,  sw842_data4, NULL},
1321	{ sw842_ptr2,  sw842_ptr2,  sw842_data2, sw842_ptr2},
1322	{ sw842_ptr2,  sw842_ptr2,  sw842_ptr2,  sw842_data2},
1323	{ sw842_ptr2,  sw842_ptr2,  sw842_ptr2,  sw842_ptr2},
1324	{ sw842_ptr2,  sw842_ptr2,  sw842_ptr4,  NULL},
1325	{ sw842_ptr4,  sw842_data4, NULL}, /* 20 (10100) */
1326	{ sw842_ptr4,  sw842_data2, sw842_ptr2,  NULL},
1327	{ sw842_ptr4,  sw842_ptr2,  sw842_data2, NULL},
1328	{ sw842_ptr4,  sw842_ptr2,  sw842_ptr2,  NULL},
1329	{ sw842_ptr4,  sw842_ptr4,  NULL},
1330	{ sw842_ptr8,  NULL}
1331};
1332
1333/* Software decompress helpers */
1334
1335static uint8_t sw842_get_byte(const char *buf, int bit)
1336{
1337	uint8_t tmpl;
1338	uint16_t tmp;
1339	tmp = htons(*(uint16_t *)(buf));
1340	tmp = (uint16_t)(tmp << bit);
1341	tmp = ntohs(tmp);
1342	memcpy(&tmpl, &tmp, 1);
1343	return tmpl;
1344}
1345
1346static uint8_t sw842_get_template(const char **buf, int *bit)
1347{
1348	uint8_t byte;
1349	byte = sw842_get_byte(*buf, *bit);
1350	byte = byte >> 3;
1351	byte &= 0x1F;
1352	*buf += (*bit + 5) / 8;
1353	*bit = (*bit + 5) % 8;
1354	return byte;
1355}
1356
1357/* repeat_count happens to be 5-bit too (like the template) */
1358static uint8_t sw842_get_repeat_count(const char **buf, int *bit)
1359{
1360	uint8_t byte;
1361	byte = sw842_get_byte(*buf, *bit);
1362	byte = byte >> 2;
1363	byte &= 0x3F;
1364	*buf += (*bit + 6) / 8;
1365	*bit = (*bit + 6) % 8;
1366	return byte;
1367}
1368
1369static uint8_t sw842_get_ptr2(const char **buf, int *bit)
1370{
1371	uint8_t ptr;
1372	ptr = sw842_get_byte(*buf, *bit);
1373	(*buf)++;
1374	return ptr;
1375}
1376
1377static uint16_t sw842_get_ptr4(const char **buf, int *bit,
1378		struct sw842_fifo *fifo)
1379{
1380	uint16_t ptr;
1381	ptr = htons(*(uint16_t *)(*buf));
1382	ptr = (uint16_t)(ptr << *bit);
1383	ptr = ptr >> 7;
1384	ptr &= 0x01FF;
1385	*buf += (*bit + 9) / 8;
1386	*bit = (*bit + 9) % 8;
1387	return ptr;
1388}
1389
1390static uint8_t sw842_get_ptr8(const char **buf, int *bit,
1391		struct sw842_fifo *fifo)
1392{
1393	return sw842_get_ptr2(buf, bit);
1394}
1395
1396/* Software decompress template ops */
1397
1398static int sw842_data8(const char **inbuf, int *inbit,
1399		unsigned char **outbuf, struct sw842_fifo *fifo)
1400{
1401	int ret;
1402
1403	ret = sw842_data4(inbuf, inbit, outbuf, fifo);
1404	if (ret)
1405		return ret;
1406	ret = sw842_data4(inbuf, inbit, outbuf, fifo);
1407	return ret;
1408}
1409
1410static int sw842_data4(const char **inbuf, int *inbit,
1411		unsigned char **outbuf, struct sw842_fifo *fifo)
1412{
1413	int ret;
1414
1415	ret = sw842_data2(inbuf, inbit, outbuf, fifo);
1416	if (ret)
1417		return ret;
1418	ret = sw842_data2(inbuf, inbit, outbuf, fifo);
1419	return ret;
1420}
1421
1422static int sw842_data2(const char **inbuf, int *inbit,
1423		unsigned char **outbuf, struct sw842_fifo *fifo)
1424{
1425	**outbuf = sw842_get_byte(*inbuf, *inbit);
1426	(*inbuf)++;
1427	(*outbuf)++;
1428	**outbuf = sw842_get_byte(*inbuf, *inbit);
1429	(*inbuf)++;
1430	(*outbuf)++;
1431	return 0;
1432}
1433
1434static int sw842_ptr8(const char **inbuf, int *inbit,
1435		unsigned char **outbuf, struct sw842_fifo *fifo)
1436{
1437	uint8_t ptr;
1438	ptr = sw842_get_ptr8(inbuf, inbit, fifo);
1439	if (!fifo->f84_full && (ptr >= fifo->f8_count))
1440		return 1;
1441	memcpy(*outbuf, fifo->f8[ptr], 8);
1442	*outbuf += 8;
1443	return 0;
1444}
1445
1446static int sw842_ptr4(const char **inbuf, int *inbit,
1447		unsigned char **outbuf, struct sw842_fifo *fifo)
1448{
1449	uint16_t ptr;
1450	ptr = sw842_get_ptr4(inbuf, inbit, fifo);
1451	if (!fifo->f84_full && (ptr >= fifo->f4_count))
1452		return 1;
1453	memcpy(*outbuf, fifo->f4[ptr], 4);
1454	*outbuf += 4;
1455	return 0;
1456}
1457
1458static int sw842_ptr2(const char **inbuf, int *inbit,
1459		unsigned char **outbuf, struct sw842_fifo *fifo)
1460{
1461	uint8_t ptr;
1462	ptr = sw842_get_ptr2(inbuf, inbit);
1463	if (!fifo->f2_full && (ptr >= fifo->f2_count))
1464		return 1;
1465	memcpy(*outbuf, fifo->f2[ptr], 2);
1466	*outbuf += 2;
1467	return 0;
1468}
1469
1470static void sw842_copy_to_fifo(const char *buf, struct sw842_fifo *fifo)
1471{
1472	unsigned char initial_f2count = fifo->f2_count;
1473
1474	memcpy(fifo->f8[fifo->f8_count], buf, 8);
1475	fifo->f4_count += 2;
1476	fifo->f8_count += 1;
1477
1478	if (!fifo->f84_full && fifo->f4_count >= 512) {
1479		fifo->f84_full = 1;
1480		fifo->f4_count /= 512;
1481	}
1482
1483	memcpy(fifo->f2[fifo->f2_count++], buf, 2);
1484	memcpy(fifo->f2[fifo->f2_count++], buf + 2, 2);
1485	memcpy(fifo->f2[fifo->f2_count++], buf + 4, 2);
1486	memcpy(fifo->f2[fifo->f2_count++], buf + 6, 2);
1487	if (fifo->f2_count < initial_f2count)
1488		fifo->f2_full = 1;
1489}
1490
1491static int sw842_decompress(const unsigned char *src, int srclen,
1492			unsigned char *dst, int *destlen,
1493			const void *wrkmem)
1494{
1495	uint8_t tmpl;
1496	const char *inbuf;
1497	int inbit = 0;
1498	unsigned char *outbuf, *outbuf_end, *origbuf, *prevbuf;
1499	const char *inbuf_end;
1500	sw842_template_op op;
1501	int opindex;
1502	int i, repeat_count;
1503	struct sw842_fifo *fifo;
1504	int ret = 0;
1505
1506	fifo = &((struct nx842_workmem *)(wrkmem))->swfifo;
1507	memset(fifo, 0, sizeof(*fifo));
1508
1509	origbuf = NULL;
1510	inbuf = src;
1511	inbuf_end = src + srclen;
1512	outbuf = dst;
1513	outbuf_end = dst + *destlen;
1514
1515	while ((tmpl = sw842_get_template(&inbuf, &inbit)) != SW842_TMPL_EOF) {
1516		if (inbuf >= inbuf_end) {
1517			ret = -EINVAL;
1518			goto out;
1519		}
1520
1521		opindex = 0;
1522		prevbuf = origbuf;
1523		origbuf = outbuf;
1524		switch (tmpl) {
1525		case SW842_TMPL_REPEAT:
1526			if (prevbuf == NULL) {
1527				ret = -EINVAL;
1528				goto out;
1529			}
1530
1531			repeat_count = sw842_get_repeat_count(&inbuf,
1532								&inbit) + 1;
1533
1534			/* Did the repeat count advance past the end of input */
1535			if (inbuf > inbuf_end) {
1536				ret = -EINVAL;
1537				goto out;
1538			}
1539
1540			for (i = 0; i < repeat_count; i++) {
1541				/* Would this overflow the output buffer */
1542				if ((outbuf + 8) > outbuf_end) {
1543					ret = -ENOSPC;
1544					goto out;
1545				}
1546
1547				memcpy(outbuf, prevbuf, 8);
1548				sw842_copy_to_fifo(outbuf, fifo);
1549				outbuf += 8;
1550			}
1551			break;
1552
1553		case SW842_TMPL_ZEROS:
1554			/* Would this overflow the output buffer */
1555			if ((outbuf + 8) > outbuf_end) {
1556				ret = -ENOSPC;
1557				goto out;
1558			}
1559
1560			memset(outbuf, 0, 8);
1561			sw842_copy_to_fifo(outbuf, fifo);
1562			outbuf += 8;
1563			break;
1564
1565		default:
1566			if (tmpl > 25) {
1567				ret = -EINVAL;
1568				goto out;
1569			}
1570
1571			/* Does this go past the end of the input buffer */
1572			if ((inbuf + 2) > inbuf_end) {
1573				ret = -EINVAL;
1574				goto out;
1575			}
1576
1577			/* Would this overflow the output buffer */
1578			if ((outbuf + 8) > outbuf_end) {
1579				ret = -ENOSPC;
1580				goto out;
1581			}
1582
1583			while (opindex < 4 &&
1584				(op = sw842_tmpl_ops[tmpl][opindex++])
1585					!= NULL) {
1586				ret = (*op)(&inbuf, &inbit, &outbuf, fifo);
1587				if (ret) {
1588					ret = -EINVAL;
1589					goto out;
1590				}
1591				sw842_copy_to_fifo(origbuf, fifo);
1592			}
1593		}
1594	}
1595
1596out:
1597	if (!ret)
1598		*destlen = (unsigned int)(outbuf - dst);
1599	else
1600		*destlen = 0;
1601
1602	return ret;
1603}
1604