Merge tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Support for userspace to send requests directly to the on-chip GZIP
   accelerator on Power9.

 - Rework of our lockless page table walking (__find_linux_pte()) to
   make it safe against parallel page table manipulations without
   relying on an IPI for serialisation.

 - A series of fixes & enhancements to make our machine check handling
   more robust.

 - Lots of plumbing to add support for "prefixed" (64-bit) instructions
   on Power10.

 - Support for using huge pages for the linear mapping on 8xx (32-bit).

 - Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound
   driver.

 - Removal of some obsolete 40x platforms and associated cruft.

 - Initial support for booting on Power10.

 - Lots of other small features, cleanups & fixes.

Thanks to: Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan,
Andrey Abramov, Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent
Abali, Cédric Le Goater, Chen Zhou, Christian Zigotzky, Christophe
JAILLET, Christophe Leroy, Dmitry Torokhov, Emmanuel Nicolet, Erhard F.,
Gautham R. Shenoy, Geoff Levand, George Spelvin, Greg Kurz, Gustavo A.
R. Silva, Gustavo Walbon, Haren Myneni, Hari Bathini, Joel Stanley,
Jordan Niethe, Kajol Jain, Kees Cook, Leonardo Bras, Madhavan
Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Michal
Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram Pai,
Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher
Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler,
Wolfram Sang, Xiongfeng Wang.

* tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (299 commits)
  powerpc/pseries: Make vio and ibmebus initcalls pseries specific
  cxl: Remove dead Kconfig options
  powerpc: Add POWER10 architected mode
  powerpc/dt_cpu_ftrs: Add MMA feature
  powerpc/dt_cpu_ftrs: Enable Prefixed Instructions
  powerpc/dt_cpu_ftrs: Advertise support for ISA v3.1 if selected
  powerpc: Add support for ISA v3.1
  powerpc: Add new HWCAP bits
  powerpc/64s: Don't set FSCR bits in INIT_THREAD
  powerpc/64s: Save FSCR to init_task.thread.fscr after feature init
  powerpc/64s: Don't let DT CPU features set FSCR_DSCR
  powerpc/64s: Don't init FSCR_DSCR in __init_FSCR()
  powerpc/32s: Fix another build failure with CONFIG_PPC_KUAP_DEBUG
  powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel
  powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations
  powerpc/module_64: Consolidate ftrace code
  powerpc/32: Disable KASAN with pages bigger than 16k
  powerpc/uaccess: Don't set KUEP by default on book3s/32
  powerpc/uaccess: Don't set KUAP by default on book3s/32
  powerpc/8xx: Reduce time spent in allow_user_access() and friends
  ...

21 files changed, 3253 insertions, 5 deletions

diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index 644770c3b754..0830e63818c1 100644
--- a/tools/testing/selftests/powerpc/Makefile
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -19,6 +19,7 @@ SUB_DIRS = alignment		\
 	   copyloops		\
 	   dscr			\
 	   mm			\
+	   nx-gzip		\
 	   pmu			\
 	   signal		\
 	   primitives		\
diff --git a/tools/testing/selftests/powerpc/nx-gzip/99-nx-gzip.rules b/tools/testing/selftests/powerpc/nx-gzip/99-nx-gzip.rules
new file mode 100644
index 000000000000..5a7118495cb3
--- /dev/null
+++ b/tools/testing/selftests/powerpc/nx-gzip/99-nx-gzip.rules
@@ -0,0 +1 @@
+SUBSYSTEM=="nxgzip", KERNEL=="nx-gzip", MODE="0666"
diff --git a/tools/testing/selftests/powerpc/nx-gzip/Makefile b/tools/testing/selftests/powerpc/nx-gzip/Makefile
new file mode 100644
index 000000000000..640fad6cc2c7
--- /dev/null
+++ b/tools/testing/selftests/powerpc/nx-gzip/Makefile
@@ -0,0 +1,8 @@
+CFLAGS = -O3 -m64 -I./include
+
+TEST_GEN_FILES := gzfht_test gunz_test
+TEST_PROGS := nx-gzip-test.sh
+
+include ../../lib.mk
+
+$(TEST_GEN_FILES): gzip_vas.c
diff --git a/tools/testing/selftests/powerpc/nx-gzip/README b/tools/testing/selftests/powerpc/nx-gzip/README
new file mode 100644
index 000000000000..9809dbaa1905
--- /dev/null
+++ b/tools/testing/selftests/powerpc/nx-gzip/README
@@ -0,0 +1,45 @@
+Test the nx-gzip function:
+=========================
+
+Verify that following device exists:
+  /dev/crypto/nx-gzip
+If you get a permission error run as sudo or set the device permissions:
+   sudo chmod go+rw /dev/crypto/nx-gzip
+However, chmod may not survive across boots. You may create a udev file such
+as:
+   /etc/udev/rules.d/99-nx-gzip.rules
+
+
+To manually build and run:
+$ gcc -O3 -I./include -o gzfht_test gzfht_test.c gzip_vas.c
+$ gcc -O3 -I./include -o gunz_test gunz_test.c gzip_vas.c
+
+
+Compress any file using Fixed Huffman mode. Output will have a .nx.gz suffix:
+$ ./gzfht_test gzip_vas.c
+file gzip_vas.c read, 6413 bytes
+compressed 6413 to 3124 bytes total, crc32 checksum = abd15e8a
+
+
+Uncompress the previous output. Output will have a .nx.gunzip suffix:
+./gunz_test gzip_vas.c.nx.gz
+gzHeader FLG 0
+00 00 00 00 04 03
+gzHeader MTIME, XFL, OS ignored
+computed checksum abd15e8a isize 0000190d
+stored   checksum abd15e8a isize 0000190d
+decomp is complete: fclose
+
+
+Compare two files:
+$ sha1sum gzip_vas.c.nx.gz.nx.gunzip gzip_vas.c
+bf43e3c0c3651f5f22b6f9784cd9b1eeab4120b6  gzip_vas.c.nx.gz.nx.gunzip
+bf43e3c0c3651f5f22b6f9784cd9b1eeab4120b6  gzip_vas.c
+
+
+Note that the code here are intended for testing the nx-gzip hardware function.
+They are not intended for demonstrating performance or compression ratio.
+By being simplistic these selftests expect to allocate the entire set of source
+and target pages in the memory so it needs enough memory to work.
+For more information and source code consider using:
+https://github.com/libnxz/power-gzip
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..6ee0fded0391
--- /dev/null
+++ b/tools/testing/selftests/powerpc/nx-gzip/gunz_test.c
@@ -0,0 +1,1028 @@
+// 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:
+ * https://github.com/libnxz/power-gzip/blob/develop/doc/power_nx_gzip_um.pdf
+ *
+ * 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
+ */
+
+#define _ISOC11_SOURCE	// For aligned_alloc()
+#define _DEFAULT_SOURCE	// For endian.h
+
+#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"
+#include "crb.h"
+
+int nx_dbg;
+FILE *nx_gzip_log;
+
+#define NX_MIN(X, Y) (((X) < (Y))?(X):(Y))
+#define NX_MAX(X, Y) (((X) > (Y))?(X):(Y))
+
+#define GETINPC(X) fgetc(X)
+#define FNAME_MAX 1024
+
+/* 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)
+
+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;
+
+/*
+ * 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(struct 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: %s addr %p len %x\n", __LINE__, addr,
+			__func__, 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(struct 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;
+	struct nx_dde_t *dde_list;
+	int i;
+
+	assert(!!ddep);
+
+	indirect_count = getpnn(ddep, dde_count);
+
+	NXPRT(fprintf(stderr, "%s dde_count %d request len ", __func__,
+			indirect_count));
+	NXPRT(fprintf(stderr, "0x%lx\n", 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)
+			nxu_touch_pages((void *)buf_addr, buf_len, page_sz, wr);
+		else
+			nxu_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 = (struct 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 ",
+				buf_len, (void *)buf_addr));
+		NXPRT(fprintf(stderr, "0x%lx\n", total));
+
+		/* Touching fewer pages than encoded in the ddebc */
+		if (total > buf_sz) {
+			buf_len = NX_MIN(buf_len, total - buf_sz);
+			nxu_touch_pages((void *)buf_addr, buf_len, page_sz, wr);
+			NXPRT(fprintf(stderr, "touch loop break len 0x%x ",
+				      buf_len));
+			NXPRT(fprintf(stderr, "ddead %p\n", (void *)buf_addr));
+			break;
+		}
+		nxu_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(struct nx_dde_t *src, struct nx_dde_t *dst,
+			 struct nx_gzip_crb_cpb_t *cmdp, void *handle)
+{
+	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);
+
+	/* Submit the crb, the job descriptor, to the accelerator. */
+	return nxu_submit_job(cmdp, handle);
+}
+
+int decompress_file(int argc, char **argv, void *devhandle)
+{
+	FILE *inpf = NULL;
+	FILE *outf = NULL;
+
+	int c, expect, i, cc, rc = 0;
+	char gzfname[FNAME_MAX];
+
+	/* 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 = 0; /* 1000 max */
+	uint64_t total_out = 0;
+	int is_final, is_eof;
+
+	/* nx hardware */
+	int sfbt, subc, spbc, tpbc, nx_ce, fc, resuming = 0;
+	int history_len = 0;
+	struct nx_gzip_crb_cpb_t cmd, *cmdp;
+	struct nx_dde_t *ddl_in;
+	struct nx_dde_t dde_in[6] __aligned(128);
+	struct nx_dde_t *ddl_out;
+	struct nx_dde_t dde_out[6] __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+1) : argv[1];
+		strcpy(w, wp);
+		strcat(w, ".nx.gunzip");
+
+		outf = fopen(w, "w");
+		if (outf == NULL) {
+			perror(w);
+			return -1;
+		}
+	}
+
+	/* 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 & 0xE0 || flg & 0x4 || flg == EOF)
+		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];
+
+		tmp[i] = GETINPC(inpf);
+		if (tmp[i] == EOF)
+			goto err3;
+		fprintf(stderr, "%02x ", tmp[i]);
+		if (i == 5)
+			fprintf(stderr, "\n");
+	}
+	fprintf(stderr, "gzHeader MTIME, XFL, OS ignored\n");
+
+	/* FNAME */
+	if (flg & 0x8) {
+		int k = 0;
+
+		do {
+			c = GETINPC(inpf);
+			if (c == EOF || k >= FNAME_MAX)
+				goto err3;
+			gzfname[k++] = c;
+		} while (c);
+		fprintf(stderr, "gzHeader FNAME: %s\n", gzfname);
+	}
+
+	/* FHCRC */
+	if (flg & 0x2) {
+		c = GETINPC(inpf);
+		if (c == EOF)
+			goto err3;
+		c = GETINPC(inpf);
+		if (c == EOF)
+			goto err3;
+		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;
+	nxu_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 = NX_MAX_FAULTS;
+
+restart_nx:
+
+	putp32(ddl_in, ddebc, source_sz);
+
+	/* Fault in pages */
+	nxu_touch_pages(cmdp, sizeof(struct nx_gzip_crb_cpb_t), page_sz, 1);
+	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));
+
+		if (pgfault_retries == NX_MAX_FAULTS) {
+			/* 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 ");
+			fprintf(stderr, "page fault retries cc= %d\n", cc);
+			rc = -1;
+			goto err5;
+		}
+
+	case ERR_NX_DATA_LENGTH:
+
+		NXPRT(fprintf(stderr, "ERR_NX_DATA_LENGTH; "));
+		NXPRT(fprintf(stderr, "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 "));
+		NXPRT(fprintf(stderr, "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