>
> Signed-off-by: Bulent Abali <abali@us.ibm.com>
> Signed-off-by: Raphael Moreira Zinsly <rzinsly@linux.ibm.com>
> ---
>  .../selftests/powerpc/nx-gzip/Makefile        |    7 +-
>  .../selftests/powerpc/nx-gzip/gunz_test.c     | 1058 +++++++++++++++++
>  2 files changed, 1062 insertions(+), 3 deletions(-)
>  create mode 100644 tools/testing/selftests/powerpc/nx-gzip/gunz_test.c
>
> diff --git a/tools/testing/selftests/powerpc/nx-gzip/Makefile b/tools/testing/selftests/powerpc/nx-gzip/Makefile
> index ab903f63bbbd..82abc19a49a0 100644
> --- a/tools/testing/selftests/powerpc/nx-gzip/Makefile
> +++ b/tools/testing/selftests/powerpc/nx-gzip/Makefile
> @@ -1,9 +1,9 @@
>  CC = gcc
>  CFLAGS = -O3
>  INC = ./inc
> -SRC = gzfht_test.c
> +SRC = gzfht_test.c gunz_test.c
>  OBJ = $(SRC:.c=.o)
> -TESTS = gzfht_test
> +TESTS = gzfht_test gunz_test
>  EXTRA_SOURCES = gzip_vas.c
>  
>  all:	$(TESTS)
> @@ -16,6 +16,7 @@ $(TESTS): $(OBJ)
>  
>  run_tests: $(TESTS)
>  	./gzfht_test gzip_vas.c
> +	./gunz_test gzip_vas.c.nx.gz
>  
>  clean:
> -	rm -f $(TESTS) *.o *~ *.gz
> +	rm -f $(TESTS) *.o *~ *.gz *.gunzip
> diff --git a/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c b/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c
> new file mode 100644
> index 000000000000..653de92698cc
> --- /dev/null
> +++ b/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c
> @@ -0,0 +1,1058 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later
> + *
> + * P9 gunzip sample code for demonstrating the P9 NX hardware
> + * interface.  Not intended for productive uses or for performance or
> + * compression ratio measurements.  Note also that /dev/crypto/gzip,
> + * VAS and skiboot support are required
> + *
> + * Copyright 2020 IBM Corp.
> + *
> + * Author: Bulent Abali <abali@us.ibm.com>
> + *
> + * https://github.com/libnxz/power-gzip for zlib api and other utils
> + * Definitions of acronyms used here.  See
> + * P9 NX Gzip Accelerator User's Manual for details
> + *
> + * adler/crc: 32 bit checksums appended to stream tail
> + * ce:       completion extension
> + * cpb:      coprocessor parameter block (metadata)
> + * crb:      coprocessor request block (command)
> + * csb:      coprocessor status block (status)
> + * dht:      dynamic huffman table
> + * dde:      data descriptor element (address, length)
> + * ddl:      list of ddes
> + * dh/fh:    dynamic and fixed huffman types
> + * fc:       coprocessor function code
> + * histlen:  history/dictionary length
> + * history:  sliding window of up to 32KB of data
> + * lzcount:  Deflate LZ symbol counts
> + * rembytecnt: remaining byte count
> + * sfbt:     source final block type; last block's type during decomp
> + * spbc:     source processed byte count
> + * subc:     source unprocessed bit count
> + * tebc:     target ending bit count; valid bits in the last byte
> + * tpbc:     target processed byte count
> + * vas:      virtual accelerator switch; the user mode interface
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <stdint.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <sys/time.h>
> +#include <sys/fcntl.h>
> +#include <sys/mman.h>
> +#include <endian.h>
> +#include <bits/endian.h>
> +#include <sys/ioctl.h>
> +#include <assert.h>
> +#include <errno.h>
> +#include <signal.h>
> +#include "nxu.h"
> +#include "nx.h"
> +
> +int nx_dbg = 0;
> +FILE *nx_gzip_log = NULL;
> +
> +#define NX_MIN(X, Y) (((X) < (Y))?(X):(Y))
> +#define NX_MAX(X, Y) (((X) > (Y))?(X):(Y))
> +
> +#define mb()     asm volatile("sync" ::: "memory")
> +#define rmb()    asm volatile("lwsync" ::: "memory")
> +#define wmb()    rmb()
> +
> +const int fifo_in_len = 1<<24;
> +const int fifo_out_len = 1<<24;
> +const int page_sz = 1<<16;
> +const int line_sz = 1<<7;
> +const int window_max = 1<<15;
> +const int retry_max = 50;
> +
> +extern void *nx_fault_storage_address;
> +extern void *nx_function_begin(int function, int pri);
> +extern int nx_function_end(void *handle);
> +
> +/*
> + * Fault in pages prior to NX job submission.  wr=1 may be required to
> + * touch writeable pages.  System zero pages do not fault-in the page as
> + * intended.  Typically set wr=1 for NX target pages and set wr=0 for
> + * NX source pages.
> + */
> +static int nx_touch_pages(void *buf, long buf_len, long page_len, int wr)
> +{
> +	char *begin = buf;
> +	char *end = (char *) buf + buf_len - 1;
> +	volatile char t;
> +
> +	assert(buf_len >= 0 && !!buf);
> +
> +	NXPRT(fprintf(stderr, "touch %p %p len 0x%lx wr=%d\n", buf,
> +			buf + buf_len, buf_len, wr));
> +
> +	if (buf_len <= 0 || buf == NULL)
> +		return -1;
> +
> +	do {
> +		t = *begin;
> +		if (wr)
> +			*begin = t;
> +		begin = begin + page_len;
> +	} while (begin < end);
> +
> +	/* When buf_sz is small or buf tail is in another page. */
> +	t = *end;
> +	if (wr)
> +		*end = t;
> +
> +	return 0;
> +}
> +
> +void sigsegv_handler(int sig, siginfo_t *info, void *ctx)
> +{
> +	fprintf(stderr, "%d: Got signal %d si_code %d, si_addr %p\n", getpid(),
> +	       sig, info->si_code, info->si_addr);
> +
> +	nx_fault_storage_address = info->si_addr;
> +}
> +
> +/*
> + * Adds an (address, len) pair to the list of ddes (ddl) and updates
> + * the base dde.  ddl[0] is the only dde in a direct dde which
> + * contains a single (addr,len) pair.  For more pairs, ddl[0] becomes
> + * the indirect (base) dde that points to a list of direct ddes.
> + * See Section 6.4 of the NX-gzip user manual for DDE description.
> + * Addr=NULL, len=0 clears the ddl[0].  Returns the total number of
> + * bytes in ddl.  Caller is responsible for allocting the array of
> + * nx_dde_t *ddl.  If N addresses are required in the scatter-gather
> + * list, the ddl array must have N+1 entries minimum.
> + */
> +static inline uint32_t nx_append_dde(nx_dde_t *ddl, void *addr, uint32_t len)
> +{
> +	uint32_t ddecnt;
> +	uint32_t bytes;
> +
> +	if (addr == NULL && len == 0) {
> +		clearp_dde(ddl);
> +		return 0;
> +	}
> +
> +	NXPRT(fprintf(stderr, "%d: nx_append_dde addr %p len %x\n", __LINE__,
> +			addr, len));
> +
> +	/* Number of ddes in the dde list ; == 0 when it is a direct dde */
> +	ddecnt = getpnn(ddl, dde_count);
> +	bytes = getp32(ddl, ddebc);
> +
> +	if (ddecnt == 0 && bytes == 0) {
> +		/* First dde is unused; make it a direct dde */
> +		bytes = len;
> +		putp32(ddl, ddebc, bytes);
> +		putp64(ddl, ddead, (uint64_t) addr);
> +	} else if (ddecnt == 0) {
> +		/* Converting direct to indirect dde
> +		 * ddl[0] becomes head dde of ddl
> +		 * copy direct to indirect first.
> +		 */
> +		ddl[1] = ddl[0];
> +
> +		/* Add the new dde next */
> +		clear_dde(ddl[2]);
> +		put32(ddl[2], ddebc, len);
> +		put64(ddl[2], ddead, (uint64_t) addr);
> +
> +		/* Ddl head points to 2 direct ddes */
> +		ddecnt = 2;
> +		putpnn(ddl, dde_count, ddecnt);
> +		bytes = bytes + len;
> +		putp32(ddl, ddebc, bytes);
> +		/* Pointer to the first direct dde */
> +		putp64(ddl, ddead, (uint64_t) &ddl[1]);
> +	} else {
> +		/* Append a dde to an existing indirect ddl */
> +		++ddecnt;
> +		clear_dde(ddl[ddecnt]);
> +		put64(ddl[ddecnt], ddead, (uint64_t) addr);
> +		put32(ddl[ddecnt], ddebc, len);
> +
> +		putpnn(ddl, dde_count, ddecnt);
> +		bytes = bytes + len;
> +		putp32(ddl, ddebc, bytes); /* byte sum of all dde */
> +	}
> +	return bytes;
> +}
> +
> +/*
> + * Touch specified number of pages represented in number bytes
> + * beginning from the first buffer in a dde list.
> + * Do not touch the pages past buf_sz-th byte's page.
> + *
> + * Set buf_sz = 0 to touch all pages described by the ddep.
> + */
> +static int nx_touch_pages_dde(nx_dde_t *ddep, long buf_sz, long page_sz,
> +				int wr)
> +{
> +	uint32_t indirect_count;
> +	uint32_t buf_len;
> +	long total;
> +	uint64_t buf_addr;
> +	nx_dde_t *dde_list;
> +	int i;
> +
> +	assert(!!ddep);
> +
> +	indirect_count = getpnn(ddep, dde_count);
> +
> +	NXPRT(fprintf(stderr, "nx_touch_pages_dde dde_count %d request len \
> +			0x%lx\n", indirect_count, buf_sz));
> +
> +	if (indirect_count == 0) {
> +		/* Direct dde */
> +		buf_len = getp32(ddep, ddebc);
> +		buf_addr = getp64(ddep, ddead);
> +
> +		NXPRT(fprintf(stderr, "touch direct ddebc 0x%x ddead %p\n",
> +				buf_len, (void *)buf_addr));
> +
> +		if (buf_sz == 0)
> +			nx_touch_pages((void *)buf_addr, buf_len, page_sz, wr);
> +		else
> +			nx_touch_pages((void *)buf_addr, NX_MIN(buf_len,
> +					buf_sz), page_sz, wr);
> +
> +		return ERR_NX_OK;
> +	}
> +
> +	/* Indirect dde */
> +	if (indirect_count > MAX_DDE_COUNT)
> +		return ERR_NX_EXCESSIVE_DDE;
> +
> +	/* First address of the list */
> +	dde_list = (nx_dde_t *) getp64(ddep, ddead);
> +
> +	if (buf_sz == 0)
> +		buf_sz = getp32(ddep, ddebc);
> +
> +	total = 0;
> +	for (i = 0; i < indirect_count; i++) {
> +		buf_len = get32(dde_list[i], ddebc);
> +		buf_addr = get64(dde_list[i], ddead);
> +		total += buf_len;
> +
> +		NXPRT(fprintf(stderr, "touch loop len 0x%x ddead %p total \
> +				0x%lx\n", buf_len, (void *)buf_addr, total));
> +
> +		/* Touching fewer pages than encoded in the ddebc */
> +		if (total > buf_sz) {
> +			buf_len = NX_MIN(buf_len, total - buf_sz);
> +			nx_touch_pages((void *)buf_addr, buf_len, page_sz, wr);
> +			NXPRT(fprintf(stderr, "touch loop break len 0x%x \
> +				      ddead %p\n", buf_len, (void *)buf_addr));
> +			break;
> +		}
> +		nx_touch_pages((void *)buf_addr, buf_len, page_sz, wr);
> +	}
> +	return ERR_NX_OK;
> +}
> +
> +/*
> + * Src and dst buffers are supplied in scatter gather lists.
> + * NX function code and other parameters supplied in cmdp.
> + */
> +static int nx_submit_job(nx_dde_t *src, nx_dde_t *dst, nx_gzip_crb_cpb_t *cmdp,
> +			 void *handle)
> +{
> +	int cc;
> +	uint64_t csbaddr;
> +
> +	memset((void *)&cmdp->crb.csb, 0, sizeof(cmdp->crb.csb));
> +
> +	cmdp->crb.source_dde = *src;
> +	cmdp->crb.target_dde = *dst;
> +
> +	/* Status, output byte count in tpbc */
> +	csbaddr = ((uint64_t) &cmdp->crb.csb) & csb_address_mask;
> +	put64(cmdp->crb, csb_address, csbaddr);
> +
> +	/* NX reports input bytes in spbc; cleared */
> +	cmdp->cpb.out_spbc_comp_wrap = 0;
> +	cmdp->cpb.out_spbc_comp_with_count = 0;
> +	cmdp->cpb.out_spbc_decomp = 0;
> +
> +	/* Clear output */
> +	put32(cmdp->cpb, out_crc, INIT_CRC);
> +	put32(cmdp->cpb, out_adler, INIT_ADLER);
> +
> +	cc = nxu_run_job(cmdp, handle);
> +
> +	if (!cc)
> +		cc = getnn(cmdp->crb.csb, csb_cc);	/* CC Table 6-8 */
> +
> +	return cc;
> +}
> +
> +/* fifo queue management */
> +#define fifo_used_bytes(used) (used)
> +#define fifo_free_bytes(used, len) ((len)-(used))
> +/* amount of free bytes in the first and last parts */
> +#define fifo_free_first_bytes(cur, used, len)  ((((cur)+(used)) <= (len)) \
> +						  ? (len)-((cur)+(used)) : 0)
> +#define fifo_free_last_bytes(cur, used, len)   ((((cur)+(used)) <= (len)) \
> +						  ? (cur) : (len)-(used))
> +/* amount of used bytes in the first and last parts */
> +#define fifo_used_first_bytes(cur, used, len)  ((((cur)+(used)) <= (len)) \
> +						  ? (used) : (len)-(cur))
> +#define fifo_used_last_bytes(cur, used, len)   ((((cur)+(used)) <= (len)) \
> +						  ? 0 : ((used)+(cur))-(len))
> +/* first and last free parts start here */
> +#define fifo_free_first_offset(cur, used)      ((cur)+(used))
> +#define fifo_free_last_offset(cur, used, len)  \
> +					   fifo_used_last_bytes(cur, used, len)
> +/* first and last used parts start here */
> +#define fifo_used_first_offset(cur)            (cur)
> +#define fifo_used_last_offset(cur)             (0)
> +
> +int decompress_file(int argc, char **argv, void *devhandle)
> +{
> +	FILE *inpf;
> +	FILE *outf;
> +
> +	int c, expect, i, cc, rc = 0;
> +	char gzfname[1024];
> +
> +	/* Queuing, file ops, byte counting */
> +	char *fifo_in, *fifo_out;
> +	int used_in, cur_in, used_out, cur_out, read_sz, n;
> +	int first_free, last_free, first_used, last_used;
> +	int first_offset, last_offset;
> +	int write_sz, free_space, source_sz;
> +	int source_sz_estimate, target_sz_estimate;
> +	uint64_t last_comp_ratio; /* 1000 max */
> +	uint64_t total_out;
> +	int is_final, is_eof;
> +
> +	/* nx hardware */
> +	int sfbt, subc, spbc, tpbc, nx_ce, fc, resuming = 0;
> +	int history_len = 0;
> +	nx_gzip_crb_cpb_t cmd, *cmdp;
> +	nx_dde_t *ddl_in;
> +	nx_dde_t dde_in[6] __attribute__((aligned (128)));
> +	nx_dde_t *ddl_out;
> +	nx_dde_t dde_out[6] __attribute__((aligned (128)));
> +	int pgfault_retries;
> +
> +	/* when using mmap'ed files */
> +	off_t input_file_offset;
> +
> +	if (argc > 2) {
> +		fprintf(stderr, "usage: %s <fname> or stdin\n", argv[0]);
> +		fprintf(stderr, "    writes to stdout or <fname>.nx.gunzip\n");
> +		return -1;
> +	}
> +
> +	if (argc == 1) {
> +		inpf = stdin;
> +		outf = stdout;
> +	} else if (argc == 2) {
> +		char w[1024];
> +		char *wp;
> +		inpf = fopen(argv[1], "r");
> +		if (inpf == NULL) {
> +			perror(argv[1]);
> +			return -1;
> +		}
> +
> +		/* Make a new file name to write to.  Ignoring '.gz' */
> +		wp = (NULL != (wp = strrchr(argv[1], '/'))) ? ++wp : argv[1];
> +		strcpy(w, wp);
> +		strcat(w, ".nx.gunzip");
> +
> +		outf = fopen(w, "w");
> +		if (outf == NULL) {
> +			perror(w);
> +			return -1;
> +		}
> +	}
> +
> +#define GETINPC(X) fgetc(X)
> +
> +	/* Decode the gzip header */
> +	c = GETINPC(inpf); expect = 0x1f; /* ID1 */
> +	if (c != expect)
> +		goto err1;
> +
> +	c = GETINPC(inpf); expect = 0x8b; /* ID2 */
> +	if (c != expect)
> +		goto err1;
> +
> +	c = GETINPC(inpf); expect = 0x08; /* CM */
> +	if (c != expect)
> +		goto err1;
> +
> +	int flg = GETINPC(inpf); /* FLG */
> +	if (flg & 0b11100000 || flg & 0b100)
> +		goto err2;
> +
> +	fprintf(stderr, "gzHeader FLG %x\n", flg);
> +
> +	/* Read 6 bytes; ignoring the MTIME, XFL, OS fields in this
> +	 * sample code.
> +	 */
> +	for (i = 0; i < 6; i++) {
> +		char tmp[10];
> +		if (EOF == (tmp[i] = GETINPC(inpf)))
> +			goto err3;
> +		fprintf(stderr, "%02x ", tmp[i]);
> +		if (i == 5)
> +			fprintf(stderr, "\n");
> +	}
> +	fprintf(stderr, "gzHeader MTIME, XFL, OS ignored\n");
> +
> +	/* FNAME */
> +	if (flg & 0b1000) {
> +		int k = 0;
> +		do {
> +			if (EOF == (c = GETINPC(inpf)))
> +				goto err3;
> +			gzfname[k++] = c;
> +		} while (c);
> +		fprintf(stderr, "gzHeader FNAME: %s\n", gzfname);
> +	}
> +
> +	/* FHCRC */
> +	if (flg & 0b10) {
> +		c = GETINPC(inpf); c = GETINPC(inpf);
> +		fprintf(stderr, "gzHeader FHCRC: ignored\n");
> +	}
> +
> +	used_in = cur_in = used_out = cur_out = 0;
> +	is_final = is_eof = 0;
> +
> +	/* Allocate one page larger to prevent page faults due to NX
> +	 * overfetching.
> +	 * Either do this (char*)(uintptr_t)aligned_alloc or use
> +	 * -std=c11 flag to make the int-to-pointer warning go away.
> +	 */
> +	assert((fifo_in  = (char *)(uintptr_t)aligned_alloc(line_sz,
> +				   fifo_in_len + page_sz)) != NULL);
> +	assert((fifo_out = (char *)(uintptr_t)aligned_alloc(line_sz,
> +				   fifo_out_len + page_sz + line_sz)) != NULL);
> +	/* Leave unused space due to history rounding rules */
> +	fifo_out = fifo_out + line_sz;
> +	nx_touch_pages(fifo_out, fifo_out_len, page_sz, 1);
> +
> +	ddl_in  = &dde_in[0];
> +	ddl_out = &dde_out[0];
> +	cmdp = &cmd;
> +	memset(&cmdp->crb, 0, sizeof(cmdp->crb));
> +
> +read_state:
> +
> +	/* Read from .gz file */
> +
> +	NXPRT(fprintf(stderr, "read_state:\n"));
> +
> +	if (is_eof != 0)
> +		goto write_state;
> +
> +	/* We read in to fifo_in in two steps: first: read in to from
> +	 * cur_in to the end of the buffer.  last: if free space wrapped
> +	 * around, read from fifo_in offset 0 to offset cur_in.
> +	 */
> +
> +	/* Reset fifo head to reduce unnecessary wrap arounds */
> +	cur_in = (used_in == 0) ? 0 : cur_in;
> +
> +	/* Free space total is reduced by a gap */
> +	free_space = NX_MAX(0, fifo_free_bytes(used_in, fifo_in_len)
> +			    - line_sz);
> +
> +	/* Free space may wrap around as first and last */
> +	first_free = fifo_free_first_bytes(cur_in, used_in, fifo_in_len);
> +	last_free  = fifo_free_last_bytes(cur_in, used_in, fifo_in_len);
> +
> +	/* Start offsets of the free memory */
> +	first_offset = fifo_free_first_offset(cur_in, used_in);
> +	last_offset  = fifo_free_last_offset(cur_in, used_in, fifo_in_len);
> +
> +	/* Reduce read_sz because of the line_sz gap */
> +	read_sz = NX_MIN(free_space, first_free);
> +	n = 0;
> +	if (read_sz > 0) {
> +		/* Read in to offset cur_in + used_in */
> +		n = fread(fifo_in + first_offset, 1, read_sz, inpf);
> +		used_in = used_in + n;
> +		free_space = free_space - n;
> +		assert(n <= read_sz);
> +		if (n != read_sz) {
> +			/* Either EOF or error; exit the read loop */
> +			is_eof = 1;
> +			goto write_state;
> +		}
> +	}
> +
> +	/* If free space wrapped around */
> +	if (last_free > 0) {
> +		/* Reduce read_sz because of the line_sz gap */
> +		read_sz = NX_MIN(free_space, last_free);
> +		n = 0;
> +		if (read_sz > 0) {
> +			n = fread(fifo_in + last_offset, 1, read_sz, inpf);
> +			used_in = used_in + n;       /* Increase used space */
> +			free_space = free_space - n; /* Decrease free space */
> +			assert(n <= read_sz);
> +			if (n != read_sz) {
> +				/* Either EOF or error; exit the read loop */
> +				is_eof = 1;
> +				goto write_state;
> +			}
> +		}
> +	}
> +
> +	/* At this point we have used_in bytes in fifo_in with the
> +	 * data head starting at cur_in and possibly wrapping around.
> +	 */
> +
> +write_state:
> +
> +	/* Write decompressed data to output file */
> +
> +	NXPRT(fprintf(stderr, "write_state:\n"));
> +
> +	if (used_out == 0)
> +		goto decomp_state;
> +
> +	/* If fifo_out has data waiting, write it out to the file to
> +	 * make free target space for the accelerator used bytes in
> +	 * the first and last parts of fifo_out.
> +	 */
> +
> +	first_used = fifo_used_first_bytes(cur_out, used_out, fifo_out_len);
> +	last_used  = fifo_used_last_bytes(cur_out, used_out, fifo_out_len);
> +
> +	write_sz = first_used;
> +
> +	n = 0;
> +	if (write_sz > 0) {
> +		n = fwrite(fifo_out + cur_out, 1, write_sz, outf);
> +		used_out = used_out - n;
> +		/* Move head of the fifo */
> +		cur_out = (cur_out + n) % fifo_out_len;
> +		assert(n <= write_sz);
> +		if (n != write_sz) {
> +			fprintf(stderr, "error: write\n");
> +			rc = -1;
> +			goto err5;
> +		}
> +	}
> +
> +	if (last_used > 0) { /* If more data available in the last part */
> +		write_sz = last_used; /* Keep it here for later */
> +		n = 0;
> +		if (write_sz > 0) {
> +			n = fwrite(fifo_out, 1, write_sz, outf);
> +			used_out = used_out - n;
> +			cur_out = (cur_out + n) % fifo_out_len;
> +			assert(n <= write_sz);
> +			if (n != write_sz) {
> +				fprintf(stderr, "error: write\n");
> +				rc = -1;
> +				goto err5;
> +			}
> +		}
> +	}
> +
> +decomp_state:
> +
> +	/* NX decompresses input data */
> +
> +	NXPRT(fprintf(stderr, "decomp_state:\n"));
> +
> +	if (is_final)
> +		goto finish_state;
> +
> +	/* Address/len lists */
> +	clearp_dde(ddl_in);
> +	clearp_dde(ddl_out);
> +
> +	/* FC, CRC, HistLen, Table 6-6 */
> +	if (resuming) {
> +		/* Resuming a partially decompressed input.
> +		 * The key to resume is supplying the 32KB
> +		 * dictionary (history) to NX, which is basically
> +		 * the last 32KB of output produced.
> +		 */
> +		fc = GZIP_FC_DECOMPRESS_RESUME;
> +
> +		cmdp->cpb.in_crc   = cmdp->cpb.out_crc;
> +		cmdp->cpb.in_adler = cmdp->cpb.out_adler;
> +
> +		/* Round up the history size to quadword.  Section 2.10 */
> +		history_len = (history_len + 15) / 16;
> +		putnn(cmdp->cpb, in_histlen, history_len);
> +		history_len = history_len * 16; /* bytes */
> +
> +		if (history_len > 0) {
> +			/* Chain in the history buffer to the DDE list */
> +			if (cur_out >= history_len) {
> +				nx_append_dde(ddl_in, fifo_out
> +					      + (cur_out - history_len),
> +					      history_len);
> +			} else {
> +				nx_append_dde(ddl_in, fifo_out
> +					      + ((fifo_out_len + cur_out)
> +					      - history_len),
> +					      history_len - cur_out);
> +				/* Up to 32KB history wraps around fifo_out */
> +				nx_append_dde(ddl_in, fifo_out, cur_out);
> +			}
> +
> +		}
> +	} else {
> +		/* First decompress job */
> +		fc = GZIP_FC_DECOMPRESS;
> +
> +		history_len = 0;
> +		/* Writing 0 clears out subc as well */
> +		cmdp->cpb.in_histlen = 0;
> +		total_out = 0;
> +
> +		put32(cmdp->cpb, in_crc, INIT_CRC);
> +		put32(cmdp->cpb, in_adler, INIT_ADLER);
> +		put32(cmdp->cpb, out_crc, INIT_CRC);
> +		put32(cmdp->cpb, out_adler, INIT_ADLER);
> +
> +		/* Assuming 10% compression ratio initially; use the
> +		 * most recently measured compression ratio as a
> +		 * heuristic to estimate the input and output
> +		 * sizes.  If we give too much input, the target buffer
> +		 * overflows and NX cycles are wasted, and then we
> +		 * must retry with smaller input size.  1000 is 100%.
> +		 */
> +		last_comp_ratio = 100UL;
> +	}
> +	cmdp->crb.gzip_fc = 0;
> +	putnn(cmdp->crb, gzip_fc, fc);
> +
> +	/*
> +	 * NX source buffers
> +	 */
> +	first_used = fifo_used_first_bytes(cur_in, used_in, fifo_in_len);
> +	last_used = fifo_used_last_bytes(cur_in, used_in, fifo_in_len);
> +
> +	if (first_used > 0)
> +		nx_append_dde(ddl_in, fifo_in + cur_in, first_used);
> +
> +	if (last_used > 0)
> +		nx_append_dde(ddl_in, fifo_in, last_used);
> +
> +	/*
> +	 * NX target buffers
> +	 */
> +	first_free = fifo_free_first_bytes(cur_out, used_out, fifo_out_len);
> +	last_free = fifo_free_last_bytes(cur_out, used_out, fifo_out_len);
> +
> +	/* Reduce output free space amount not to overwrite the history */
> +	int target_max = NX_MAX(0, fifo_free_bytes(used_out, fifo_out_len)
> +				- (1<<16));
> +
> +	NXPRT(fprintf(stderr, "target_max %d (0x%x)\n", target_max,
> +		      target_max));
> +
> +	first_free = NX_MIN(target_max, first_free);
> +	if (first_free > 0) {
> +		first_offset = fifo_free_first_offset(cur_out, used_out);
> +		nx_append_dde(ddl_out, fifo_out + first_offset, first_free);
> +	}
> +
> +	if (last_free > 0) {
> +		last_free = NX_MIN(target_max - first_free, last_free);
> +		if (last_free > 0) {
> +			last_offset = fifo_free_last_offset(cur_out, used_out,
> +							    fifo_out_len);
> +			nx_append_dde(ddl_out, fifo_out + last_offset,
> +				      last_free);
> +		}
> +	}
> +
> +	/* Target buffer size is used to limit the source data size
> +	 * based on previous measurements of compression ratio.
> +	 */
> +
> +	/* source_sz includes history */
> +	source_sz = getp32(ddl_in, ddebc);
> +	assert(source_sz > history_len);
> +	source_sz = source_sz - history_len;
> +
> +	/* Estimating how much source is needed to 3/4 fill a
> +	 * target_max size target buffer.  If we overshoot, then NX
> +	 * must repeat the job with smaller input and we waste
> +	 * bandwidth.  If we undershoot then we use more NX calls than
> +	 * necessary.
> +	 */
> +
> +	source_sz_estimate = ((uint64_t)target_max * last_comp_ratio * 3UL)
> +				/ 4000;
> +
> +	if (source_sz_estimate < source_sz) {
> +		/* Target might be small, therefore limiting the
> +		 * source data.
> +		 */
> +		source_sz = source_sz_estimate;
> +		target_sz_estimate = target_max;
> +	} else {
> +		/* Source file might be small, therefore limiting target
> +		 * touch pages to a smaller value to save processor cycles.
> +		 */
> +		target_sz_estimate = ((uint64_t)source_sz * 1000UL)
> +					/ (last_comp_ratio + 1);
> +		target_sz_estimate = NX_MIN(2 * target_sz_estimate,
> +					    target_max);
> +	}
> +
> +	source_sz = source_sz + history_len;
> +
> +	/* Some NX condition codes require submitting the NX job again.
> +	 * Kernel doesn't handle NX page faults. Expects user code to
> +	 * touch pages.
> +	 */
> +	pgfault_retries = retry_max;
> +
> +restart_nx:
> +
> +	putp32(ddl_in, ddebc, source_sz);
> +
> +	/* Fault in pages */
> +	nx_touch_pages_dde(ddl_in, 0, page_sz, 0);
> +	nx_touch_pages_dde(ddl_out, target_sz_estimate, page_sz, 1);
> +
> +	/* Send job to NX */
> +	cc = nx_submit_job(ddl_in, ddl_out, cmdp, devhandle);
> +
> +	switch (cc) {
> +
> +	case ERR_NX_TRANSLATION:
> +
> +		/* We touched the pages ahead of time.  In the most common case
> +		 * we shouldn't be here.  But may be some pages were paged out.
> +		 * Kernel should have placed the faulting address to fsaddr.
> +		 */
> +		NXPRT(fprintf(stderr, "ERR_NX_TRANSLATION %p\n",
> +			      (void *)cmdp->crb.csb.fsaddr));
> +
> +		/* Touch 1 byte, read-only  */
> +		nx_touch_pages((void *)cmdp->crb.csb.fsaddr, 1, page_sz, 0);
> +
> +		if (pgfault_retries == retry_max) {
> +			/* Try once with exact number of pages */
> +			--pgfault_retries;
> +			goto restart_nx;
> +		} else if (pgfault_retries > 0) {
> +			/* If still faulting try fewer input pages
> +			 * assuming memory outage
> +			 */
> +			if (source_sz > page_sz)
> +				source_sz = NX_MAX(source_sz / 2, page_sz);
> +			--pgfault_retries;
> +			goto restart_nx;
> +		} else {
> +			fprintf(stderr, "cannot make progress; too many page \
> +				fault retries cc= %d\n", cc);
> +			rc = -1;
> +			goto err5;
> +		}
> +
> +	case ERR_NX_DATA_LENGTH:
> +
> +		NXPRT(fprintf(stderr, "ERR_NX_DATA_LENGTH; not an error \
> +			      usually; stream may have trailing data\n"));
> +
> +		/* Not an error in the most common case; it just says
> +		 * there is trailing data that we must examine.
> +		 *
> +		 * CC=3 CE(1)=0 CE(0)=1 indicates partial completion
> +		 * Fig.6-7 and Table 6-8.
> +		 */
> +		nx_ce = get_csb_ce_ms3b(cmdp->crb.csb);
> +
> +		if (!csb_ce_termination(nx_ce) &&
> +		    csb_ce_partial_completion(nx_ce)) {
> +			/* Check CPB for more information
> +			 * spbc and tpbc are valid
> +			 */
> +			sfbt = getnn(cmdp->cpb, out_sfbt); /* Table 6-4 */
> +			subc = getnn(cmdp->cpb, out_subc); /* Table 6-4 */
> +			spbc = get32(cmdp->cpb, out_spbc_decomp);
> +			tpbc = get32(cmdp->crb.csb, tpbc);
> +			assert(target_max >= tpbc);
> +
> +			goto ok_cc3; /* not an error */
> +		} else {
> +			/* History length error when CE(1)=1 CE(0)=0. */
> +			rc = -1;
> +			fprintf(stderr, "history length error cc= %d\n", cc);
> +			goto err5;
> +		}
> +
> +	case ERR_NX_TARGET_SPACE:
> +
> +		/* Target buffer not large enough; retry smaller input
> +		 * data; give at least 1 byte.  SPBC/TPBC are not valid.
> +		 */
> +		assert(source_sz > history_len);
> +		source_sz = ((source_sz - history_len + 2) / 2) + history_len;
> +		NXPRT(fprintf(stderr, "ERR_NX_TARGET_SPACE; retry with \
> +			      smaller input data src %d hist %d\n", source_sz,
> +			      history_len));
> +		goto restart_nx;
> +
> +	case ERR_NX_OK:
> +
> +		/* This should not happen for gzip formatted data;
> +		 * we need trailing crc and isize
> +		 */
> +		fprintf(stderr, "ERR_NX_OK\n");
> +		spbc = get32(cmdp->cpb, out_spbc_decomp);
> +		tpbc = get32(cmdp->crb.csb, tpbc);
> +		assert(target_max >= tpbc);
> +		assert(spbc >= history_len);
> +		source_sz = spbc - history_len;
> +		goto offsets_state;
> +
> +	default:
> +		fprintf(stderr, "error: cc= %d\n", cc);
> +		rc = -1;
> +		goto err5;
> +	}
> +
> +ok_cc3:
> +
> +	NXPRT(fprintf(stderr, "cc3: sfbt: %x\n", sfbt));
> +
> +	assert(spbc > history_len);
> +	source_sz = spbc - history_len;
> +
> +	/* Table 6-4: Source Final Block Type (SFBT) describes the
> +	 * last processed deflate block and clues the software how to
> +	 * resume the next job.  SUBC indicates how many input bits NX
> +	 * consumed but did not process.  SPBC indicates how many
> +	 * bytes of source were given to the accelerator including
> +	 * history bytes.
> +	 */
> +
> +	switch (sfbt) {
> +		int dhtlen;
> +
> +	case 0b0000: /* Deflate final EOB received */
> +
> +		/* Calculating the checksum start position. */
> +
> +		source_sz = source_sz - subc / 8;
> +		is_final = 1;
> +		break;
> +
> +		/* Resume decompression cases are below. Basically
> +		 * indicates where NX has suspended and how to resume
> +		 * the input stream.
> +		 */
> +
> +	case 0b1000: /* Within a literal block; use rembytecount */
> +	case 0b1001: /* Within a literal block; use rembytecount; bfinal=1 */
> +
> +		/* Supply the partially processed source byte again */
> +		source_sz = source_sz - ((subc + 7) / 8);
> +
> +		/* SUBC LS 3bits: number of bits in the first source byte need
> +		 * to be processed.
> +		 * 000 means all 8 bits;  Table 6-3
> +		 * Clear subc, histlen, sfbt, rembytecnt, dhtlen
> +		 */
> +		cmdp->cpb.in_subc = 0;
> +		cmdp->cpb.in_sfbt = 0;
> +		putnn(cmdp->cpb, in_subc, subc % 8);
> +		putnn(cmdp->cpb, in_sfbt, sfbt);
> +		putnn(cmdp->cpb, in_rembytecnt, getnn(cmdp->cpb,
> +						      out_rembytecnt));
> +		break;
> +
> +	case 0b1010: /* Within a FH block; */
> +	case 0b1011: /* Within a FH block; bfinal=1 */
> +
> +		source_sz = source_sz - ((subc + 7) / 8);
> +
> +		/* Clear subc, histlen, sfbt, rembytecnt, dhtlen */
> +		cmdp->cpb.in_subc = 0;
> +		cmdp->cpb.in_sfbt = 0;
> +		putnn(cmdp->cpb, in_subc, subc % 8);
> +		putnn(cmdp->cpb, in_sfbt, sfbt);
> +		break;
> +
> +	case 0b1100: /* Within a DH block; */
> +	case 0b1101: /* Within a DH block; bfinal=1 */
> +
> +		source_sz = source_sz - ((subc + 7) / 8);
> +
> +		/* Clear subc, histlen, sfbt, rembytecnt, dhtlen */
> +		cmdp->cpb.in_subc = 0;
> +		cmdp->cpb.in_sfbt = 0;
> +		putnn(cmdp->cpb, in_subc, subc % 8);
> +		putnn(cmdp->cpb, in_sfbt, sfbt);
> +
> +		dhtlen = getnn(cmdp->cpb, out_dhtlen);
> +		putnn(cmdp->cpb, in_dhtlen, dhtlen);
> +		assert(dhtlen >= 42);
> +
> +		/* Round up to a qword */
> +		dhtlen = (dhtlen + 127) / 128;
> +
> +		while (dhtlen > 0) { /* Copy dht from cpb.out to cpb.in */
> +			--dhtlen;
> +			cmdp->cpb.in_dht[dhtlen] = cmdp->cpb.out_dht[dhtlen];
> +		}
> +		break;
> +
> +	case 0b1110: /* Within a block header; bfinal=0; */
> +		     /* Also given if source data exactly ends (SUBC=0) with
> +		      * EOB code with BFINAL=0.  Means the next byte will
> +		      * contain a block header.
> +		      */
> +	case 0b1111: /* within a block header with BFINAL=1. */
> +
> +		source_sz = source_sz - ((subc + 7) / 8);
> +
> +		/* Clear subc, histlen, sfbt, rembytecnt, dhtlen */
> +		cmdp->cpb.in_subc = 0;
> +		cmdp->cpb.in_sfbt = 0;
> +		putnn(cmdp->cpb, in_subc, subc % 8);
> +		putnn(cmdp->cpb, in_sfbt, sfbt);
> +	}
> +
> +offsets_state:
> +
> +	/* Adjust the source and target buffer offsets and lengths  */
> +
> +	NXPRT(fprintf(stderr, "offsets_state:\n"));
> +
> +	/* Delete input data from fifo_in */
> +	used_in = used_in - source_sz;
> +	cur_in = (cur_in + source_sz) % fifo_in_len;
> +	input_file_offset = input_file_offset + source_sz;
> +
> +	/* Add output data to fifo_out */
> +	used_out = used_out + tpbc;
> +
> +	assert(used_out <= fifo_out_len);
> +
> +	total_out = total_out + tpbc;
> +
> +	/* Deflate history is 32KB max.  No need to supply more
> +	 * than 32KB on a resume.
> +	 */
> +	history_len = (total_out > window_max) ? window_max : total_out;
> +
> +	/* To estimate expected expansion in the next NX job; 500 means 50%.
> +	 * Deflate best case is around 1 to 1000.
> +	 */
> +	last_comp_ratio = (1000UL * ((uint64_t)source_sz + 1))
> +			  / ((uint64_t)tpbc + 1);
> +	last_comp_ratio = NX_MAX(NX_MIN(1000UL, last_comp_ratio), 1);
> +	NXPRT(fprintf(stderr, "comp_ratio %ld source_sz %d spbc %d tpbc %d\n",
> +		      last_comp_ratio, source_sz, spbc, tpbc));
> +
> +	resuming = 1;
> +
> +finish_state:
> +
> +	NXPRT(fprintf(stderr, "finish_state:\n"));
> +
> +	if (is_final) {
> +		if (used_out)
> +			goto write_state; /* More data to write out */
> +		else if (used_in < 8) {
> +			/* Need at least 8 more bytes containing gzip crc
> +			 * and isize.
> +			 */
> +			rc = -1;
> +			goto err4;
> +		} else {
> +			/* Compare checksums and exit */
> +			int i;
> +			char tail[8];
> +			uint32_t cksum, isize;
> +			for (i = 0; i < 8; i++)
> +				tail[i] = fifo_in[(cur_in + i) % fifo_in_len];
> +			fprintf(stderr, "computed checksum %08x isize %08x\n",
> +				cmdp->cpb.out_crc, (uint32_t) (total_out
> +				% (1ULL<<32)));
> +			cksum = (tail[0] | tail[1]<<8 | tail[2]<<16
> +				| tail[3]<<24);
> +			isize = (tail[4] | tail[5]<<8 | tail[6]<<16
> +				| tail[7]<<24);
> +			fprintf(stderr, "stored   checksum %08x isize %08x\n",
> +				cksum, isize);
> +
> +			if (cksum == cmdp->cpb.out_crc && isize == (uint32_t)
> +			    (total_out % (1ULL<<32))) {
> +				rc = 0;	goto ok1;
> +			} else {
> +				rc = -1; goto err4;
> +			}
> +		}
> +	} else
> +		goto read_state;
> +
> +	return -1;
> +
> +err1:
> +	fprintf(stderr, "error: not a gzip file, expect %x, read %x\n",
> +		expect, c);
> +	return -1;
> +
> +err2:
> +	fprintf(stderr, "error: the FLG byte is wrong or not handled by this \
> +		code sample\n");
> +	return -1;
> +
> +err3:
> +	fprintf(stderr, "error: gzip header\n");
> +	return -1;
> +
> +err4:
> +	fprintf(stderr, "error: checksum\n");
> +
> +err5:
> +ok1:
> +	fprintf(stderr, "decomp is complete: fclose\n");
> +	fclose(outf);
> +
> +	return rc;
> +}
> +
> +
> +int main(int argc, char **argv)
> +{
> +	int rc;
> +	struct sigaction act;
> +	void *handle;
> +
> +	act.sa_handler = 0;
> +	act.sa_sigaction = sigsegv_handler;
> +	act.sa_flags = SA_SIGINFO;
> +	act.sa_restorer = 0;
> +	sigemptyset(&act.sa_mask);
> +	sigaction(SIGSEGV, &act, NULL);
> +
> +	handle = nx_function_begin(NX_FUNC_COMP_GZIP, 0);
> +	if (!handle) {
> +		fprintf(stderr, "Unable to init NX, errno %d\n", errno);
> +		exit(-1);
> +	}
> +
> +	rc = decompress_file(argc, argv, handle);
> +
> +	nx_function_end(handle);
> +
> +	return rc;
> +}
> -- 
> 2.21.0