1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 /* P9 gzip sample code for demonstrating the P9 NX hardware interface.
4  * Not intended for productive uses or for performance or compression
5  * ratio measurements.  For simplicity of demonstration, this sample
6  * code compresses in to fixed Huffman blocks only (Deflate btype=1)
7  * and has very simple memory management.  Dynamic Huffman blocks
8  * (Deflate btype=2) are more involved as detailed in the user guide.
9  * Note also that /dev/crypto/gzip, VAS and skiboot support are
10  * required.
11  *
12  * Copyright 2020 IBM Corp.
13  *
14  * https://github.com/libnxz/power-gzip for zlib api and other utils
15  *
16  * Author: Bulent Abali <abali@us.ibm.com>
17  *
18  * Definitions of acronyms used here. See
19  * P9 NX Gzip Accelerator User's Manual for details:
20  * https://github.com/libnxz/power-gzip/blob/develop/doc/power_nx_gzip_um.pdf
21  *
22  * adler/crc: 32 bit checksums appended to stream tail
23  * ce:       completion extension
24  * cpb:      coprocessor parameter block (metadata)
25  * crb:      coprocessor request block (command)
26  * csb:      coprocessor status block (status)
27  * dht:      dynamic huffman table
28  * dde:      data descriptor element (address, length)
29  * ddl:      list of ddes
30  * dh/fh:    dynamic and fixed huffman types
31  * fc:       coprocessor function code
32  * histlen:  history/dictionary length
33  * history:  sliding window of up to 32KB of data
34  * lzcount:  Deflate LZ symbol counts
35  * rembytecnt: remaining byte count
36  * sfbt:     source final block type; last block's type during decomp
37  * spbc:     source processed byte count
38  * subc:     source unprocessed bit count
39  * tebc:     target ending bit count; valid bits in the last byte
40  * tpbc:     target processed byte count
41  * vas:      virtual accelerator switch; the user mode interface
42  */
43 
44 #define _ISOC11_SOURCE	// For aligned_alloc()
45 #define _DEFAULT_SOURCE	// For endian.h
46 
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <stdint.h>
52 #include <sys/types.h>
53 #include <sys/stat.h>
54 #include <sys/time.h>
55 #include <sys/fcntl.h>
56 #include <sys/mman.h>
57 #include <endian.h>
58 #include <bits/endian.h>
59 #include <sys/ioctl.h>
60 #include <assert.h>
61 #include <errno.h>
62 #include <signal.h>
63 #include "utils.h"
64 #include "nxu.h"
65 #include "nx.h"
66 
67 int nx_dbg;
68 FILE *nx_gzip_log;
69 
70 #define NX_MIN(X, Y) (((X) < (Y)) ? (X) : (Y))
71 #define FNAME_MAX 1024
72 #define FEXT ".nx.gz"
73 
74 #define SYSFS_MAX_REQ_BUF_PATH "devices/vio/ibm,compression-v1/nx_gzip_caps/req_max_processed_len"
75 
76 /*
77  * LZ counts returned in the user supplied nx_gzip_crb_cpb_t structure.
78  */
compress_fht_sample(char * src,uint32_t srclen,char * dst,uint32_t dstlen,int with_count,struct nx_gzip_crb_cpb_t * cmdp,void * handle)79 static int compress_fht_sample(char *src, uint32_t srclen, char *dst,
80 				uint32_t dstlen, int with_count,
81 				struct nx_gzip_crb_cpb_t *cmdp, void *handle)
82 {
83 	uint32_t fc;
84 
85 	assert(!!cmdp);
86 
87 	put32(cmdp->crb, gzip_fc, 0);  /* clear */
88 	fc = (with_count) ? GZIP_FC_COMPRESS_RESUME_FHT_COUNT :
89 			    GZIP_FC_COMPRESS_RESUME_FHT;
90 	putnn(cmdp->crb, gzip_fc, fc);
91 	putnn(cmdp->cpb, in_histlen, 0); /* resuming with no history */
92 	memset((void *) &cmdp->crb.csb, 0, sizeof(cmdp->crb.csb));
93 
94 	/* Section 6.6 programming notes; spbc may be in two different
95 	 * places depending on FC.
96 	 */
97 	if (!with_count)
98 		put32(cmdp->cpb, out_spbc_comp, 0);
99 	else
100 		put32(cmdp->cpb, out_spbc_comp_with_count, 0);
101 
102 	/* Figure 6-3 6-4; CSB location */
103 	put64(cmdp->crb, csb_address, 0);
104 	put64(cmdp->crb, csb_address,
105 	      (uint64_t) &cmdp->crb.csb & csb_address_mask);
106 
107 	/* Source direct dde (scatter-gather list) */
108 	clear_dde(cmdp->crb.source_dde);
109 	putnn(cmdp->crb.source_dde, dde_count, 0);
110 	put32(cmdp->crb.source_dde, ddebc, srclen);
111 	put64(cmdp->crb.source_dde, ddead, (uint64_t) src);
112 
113 	/* Target direct dde (scatter-gather list) */
114 	clear_dde(cmdp->crb.target_dde);
115 	putnn(cmdp->crb.target_dde, dde_count, 0);
116 	put32(cmdp->crb.target_dde, ddebc, dstlen);
117 	put64(cmdp->crb.target_dde, ddead, (uint64_t) dst);
118 
119 	/* Submit the crb, the job descriptor, to the accelerator */
120 	return nxu_submit_job(cmdp, handle);
121 }
122 
123 /*
124  * Prepares a blank no filename no timestamp gzip header and returns
125  * the number of bytes written to buf.
126  * Gzip specification at https://tools.ietf.org/html/rfc1952
127  */
gzip_header_blank(char * buf)128 int gzip_header_blank(char *buf)
129 {
130 	int i = 0;
131 
132 	buf[i++] = 0x1f; /* ID1 */
133 	buf[i++] = 0x8b; /* ID2 */
134 	buf[i++] = 0x08; /* CM  */
135 	buf[i++] = 0x00; /* FLG */
136 	buf[i++] = 0x00; /* MTIME */
137 	buf[i++] = 0x00; /* MTIME */
138 	buf[i++] = 0x00; /* MTIME */
139 	buf[i++] = 0x00; /* MTIME */
140 	buf[i++] = 0x04; /* XFL 4=fastest */
141 	buf[i++] = 0x03; /* OS UNIX */
142 
143 	return i;
144 }
145 
146 /*
147  * Z_SYNC_FLUSH as described in zlib.h.
148  * Returns number of appended bytes
149  */
append_sync_flush(char * buf,int tebc,int final)150 int append_sync_flush(char *buf, int tebc, int final)
151 {
152 	uint64_t flush;
153 	int shift = (tebc & 0x7);
154 
155 	if (tebc > 0) {
156 		/* Last byte is partially full */
157 		buf = buf - 1;
158 		*buf = *buf & (unsigned char) ((1<<tebc)-1);
159 	} else
160 		*buf = 0;
161 	flush = ((0x1ULL & final) << shift) | *buf;
162 	shift = shift + 3; /* BFINAL and BTYPE written */
163 	shift = (shift <= 8) ? 8 : 16;
164 	flush |= (0xFFFF0000ULL) << shift; /* Zero length block */
165 	shift = shift + 32;
166 	while (shift > 0) {
167 		*buf++ = (unsigned char) (flush & 0xffULL);
168 		flush = flush >> 8;
169 		shift = shift - 8;
170 	}
171 	return(((tebc > 5) || (tebc == 0)) ? 5 : 4);
172 }
173 
174 /*
175  * Final deflate block bit.  This call assumes the block
176  * beginning is byte aligned.
177  */
set_bfinal(void * buf,int bfinal)178 static void set_bfinal(void *buf, int bfinal)
179 {
180 	char *b = buf;
181 
182 	if (bfinal)
183 		*b = *b | (unsigned char) 0x01;
184 	else
185 		*b = *b & (unsigned char) 0xfe;
186 }
187 
compress_file(int argc,char ** argv,void * handle)188 int compress_file(int argc, char **argv, void *handle)
189 {
190 	char *inbuf, *outbuf, *srcbuf, *dstbuf;
191 	char outname[FNAME_MAX];
192 	uint32_t srclen, dstlen;
193 	uint32_t flushlen, chunk;
194 	size_t inlen, outlen, dsttotlen, srctotlen;
195 	uint32_t crc, spbc, tpbc, tebc;
196 	int lzcounts = 0;
197 	int cc;
198 	int num_hdr_bytes;
199 	struct nx_gzip_crb_cpb_t *cmdp;
200 	uint32_t pagelen = 65536;
201 	int fault_tries = NX_MAX_FAULTS;
202 	char buf[32];
203 
204 	cmdp = (void *)(uintptr_t)
205 		aligned_alloc(sizeof(struct nx_gzip_crb_cpb_t),
206 			      sizeof(struct nx_gzip_crb_cpb_t));
207 
208 	if (argc != 2) {
209 		fprintf(stderr, "usage: %s <fname>\n", argv[0]);
210 		exit(-1);
211 	}
212 	if (read_file_alloc(argv[1], &inbuf, &inlen))
213 		exit(-1);
214 	fprintf(stderr, "file %s read, %ld bytes\n", argv[1], inlen);
215 
216 	/* Generous output buffer for header/trailer */
217 	outlen = 2 * inlen + 1024;
218 
219 	assert(NULL != (outbuf = (char *)malloc(outlen)));
220 	nxu_touch_pages(outbuf, outlen, pagelen, 1);
221 
222 	/*
223 	 * On PowerVM, the hypervisor defines the maximum request buffer
224 	 * size is defined and this value is available via sysfs.
225 	 */
226 	if (!read_sysfs_file(SYSFS_MAX_REQ_BUF_PATH, buf, sizeof(buf))) {
227 		chunk = atoi(buf);
228 	} else {
229 		/* sysfs entry is not available on PowerNV */
230 		/* Compress piecemeal in smallish chunks */
231 		chunk = 1<<22;
232 	}
233 
234 	/* Write the gzip header to the stream */
235 	num_hdr_bytes = gzip_header_blank(outbuf);
236 	dstbuf    = outbuf + num_hdr_bytes;
237 	outlen    = outlen - num_hdr_bytes;
238 	dsttotlen = num_hdr_bytes;
239 
240 	srcbuf    = inbuf;
241 	srctotlen = 0;
242 
243 	/* Init the CRB, the coprocessor request block */
244 	memset(&cmdp->crb, 0, sizeof(cmdp->crb));
245 
246 	/* Initial gzip crc32 */
247 	put32(cmdp->cpb, in_crc, 0);
248 
249 	while (inlen > 0) {
250 
251 		/* Submit chunk size source data per job */
252 		srclen = NX_MIN(chunk, inlen);
253 		/* Supply large target in case data expands */
254 		dstlen = NX_MIN(2*srclen, outlen);
255 
256 		/* Page faults are handled by the user code */
257 
258 		/* Fault-in pages; an improved code wouldn't touch so
259 		 * many pages but would try to estimate the
260 		 * compression ratio and adjust both the src and dst
261 		 * touch amounts.
262 		 */
263 		nxu_touch_pages(cmdp, sizeof(struct nx_gzip_crb_cpb_t), pagelen,
264 				1);
265 		nxu_touch_pages(srcbuf, srclen, pagelen, 0);
266 		nxu_touch_pages(dstbuf, dstlen, pagelen, 1);
267 
268 		cc = compress_fht_sample(
269 			srcbuf, srclen,
270 			dstbuf, dstlen,
271 			lzcounts, cmdp, handle);
272 
273 		if (cc != ERR_NX_OK && cc != ERR_NX_TPBC_GT_SPBC &&
274 		    cc != ERR_NX_AT_FAULT) {
275 			fprintf(stderr, "nx error: cc= %d\n", cc);
276 			exit(-1);
277 		}
278 
279 		/* Page faults are handled by the user code */
280 		if (cc == ERR_NX_AT_FAULT) {
281 			NXPRT(fprintf(stderr, "page fault: cc= %d, ", cc));
282 			NXPRT(fprintf(stderr, "try= %d, fsa= %08llx\n",
283 				  fault_tries,
284 				  (unsigned long long) cmdp->crb.csb.fsaddr));
285 			fault_tries--;
286 			if (fault_tries > 0) {
287 				continue;
288 			} else {
289 				fprintf(stderr, "error: cannot progress; ");
290 				fprintf(stderr, "too many faults\n");
291 				exit(-1);
292 			}
293 		}
294 
295 		fault_tries = NX_MAX_FAULTS; /* Reset for the next chunk */
296 
297 		inlen     = inlen - srclen;
298 		srcbuf    = srcbuf + srclen;
299 		srctotlen = srctotlen + srclen;
300 
301 		/* Two possible locations for spbc depending on the function
302 		 * code.
303 		 */
304 		spbc = (!lzcounts) ? get32(cmdp->cpb, out_spbc_comp) :
305 			get32(cmdp->cpb, out_spbc_comp_with_count);
306 		assert(spbc == srclen);
307 
308 		/* Target byte count */
309 		tpbc = get32(cmdp->crb.csb, tpbc);
310 		/* Target ending bit count */
311 		tebc = getnn(cmdp->cpb, out_tebc);
312 		NXPRT(fprintf(stderr, "compressed chunk %d ", spbc));
313 		NXPRT(fprintf(stderr, "to %d bytes, tebc= %d\n", tpbc, tebc));
314 
315 		if (inlen > 0) { /* More chunks to go */
316 			set_bfinal(dstbuf, 0);
317 			dstbuf    = dstbuf + tpbc;
318 			dsttotlen = dsttotlen + tpbc;
319 			outlen    = outlen - tpbc;
320 			/* Round up to the next byte with a flush
321 			 * block; do not set the BFINAqL bit.
322 			 */
323 			flushlen  = append_sync_flush(dstbuf, tebc, 0);
324 			dsttotlen = dsttotlen + flushlen;
325 			outlen    = outlen - flushlen;
326 			dstbuf    = dstbuf + flushlen;
327 			NXPRT(fprintf(stderr, "added sync_flush %d bytes\n",
328 					flushlen));
329 		} else {  /* Done */
330 			/* Set the BFINAL bit of the last block per Deflate
331 			 * specification.
332 			 */
333 			set_bfinal(dstbuf, 1);
334 			dstbuf    = dstbuf + tpbc;
335 			dsttotlen = dsttotlen + tpbc;
336 			outlen    = outlen - tpbc;
337 		}
338 
339 		/* Resuming crc32 for the next chunk */
340 		crc = get32(cmdp->cpb, out_crc);
341 		put32(cmdp->cpb, in_crc, crc);
342 		crc = be32toh(crc);
343 	}
344 
345 	/* Append crc32 and ISIZE to the end */
346 	memcpy(dstbuf, &crc, 4);
347 	memcpy(dstbuf+4, &srctotlen, 4);
348 	dsttotlen = dsttotlen + 8;
349 	outlen    = outlen - 8;
350 
351 	assert(FNAME_MAX > (strlen(argv[1]) + strlen(FEXT)));
352 	strcpy(outname, argv[1]);
353 	strcat(outname, FEXT);
354 	if (write_file(outname, outbuf, dsttotlen)) {
355 		fprintf(stderr, "write error: %s\n", outname);
356 		exit(-1);
357 	}
358 
359 	fprintf(stderr, "compressed %ld to %ld bytes total, ", srctotlen,
360 		dsttotlen);
361 	fprintf(stderr, "crc32 checksum = %08x\n", crc);
362 
363 	if (inbuf != NULL)
364 		free(inbuf);
365 
366 	if (outbuf != NULL)
367 		free(outbuf);
368 
369 	return 0;
370 }
371 
main(int argc,char ** argv)372 int main(int argc, char **argv)
373 {
374 	int rc;
375 	struct sigaction act;
376 	void *handle;
377 
378 	nx_dbg = 0;
379 	nx_gzip_log = NULL;
380 	act.sa_handler = 0;
381 	act.sa_sigaction = nxu_sigsegv_handler;
382 	act.sa_flags = SA_SIGINFO;
383 	act.sa_restorer = 0;
384 	sigemptyset(&act.sa_mask);
385 	sigaction(SIGSEGV, &act, NULL);
386 
387 	handle = nx_function_begin(NX_FUNC_COMP_GZIP, 0);
388 	if (!handle) {
389 		fprintf(stderr, "Unable to init NX, errno %d\n", errno);
390 		exit(-1);
391 	}
392 
393 	rc = compress_file(argc, argv, handle);
394 
395 	nx_function_end(handle);
396 
397 	return rc;
398 }
399