// SPDX-License-Identifier: GPL-2.0

  #ifdef STATIC

  #define PREBOOT

  /* Pre-boot environment: included */
  
  /* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
   * errors about console_printk etc... on ARM */
  #define _LINUX_KERNEL_H
  
  #include "zlib_inflate/inftrees.c"
  #include "zlib_inflate/inffast.c"
  #include "zlib_inflate/inflate.c"

  #ifdef CONFIG_ZLIB_DFLTCC
  #include "zlib_dfltcc/dfltcc.c"
  #include "zlib_dfltcc/dfltcc_inflate.c"
  #endif

  
  #else /* STATIC */
  /* initramfs et al: linked */
  
  #include <linux/zutil.h>
  
  #include "zlib_inflate/inftrees.h"
  #include "zlib_inflate/inffast.h"
  #include "zlib_inflate/inflate.h"
  
  #include "zlib_inflate/infutil.h"

  #include <linux/decompress/inflate.h>

  
  #endif /* STATIC */
  
  #include <linux/decompress/mm.h>

  #define GZIP_IOBUF_SIZE (16*1024)

  static long INIT nofill(void *buffer, unsigned long len)

  {
  	return -1;
  }

  /* Included from initramfs et al code */

  STATIC int INIT __gunzip(unsigned char *buf, long len,

  		       long (*fill)(void*, unsigned long),
  		       long (*flush)(void*, unsigned long),

  		       unsigned char *out_buf, long out_len,

  		       long *pos,

  		       void(*error)(char *x)) {

  	u8 *zbuf;
  	struct z_stream_s *strm;
  	int rc;

  	rc = -1;
  	if (flush) {

  		out_len = 0x8000; /* 32 K */

  		out_buf = malloc(out_len);
  	} else {

  		if (!out_len)
  			out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */

  	}
  	if (!out_buf) {
  		error("Out of memory while allocating output buffer");
  		goto gunzip_nomem1;
  	}
  
  	if (buf)
  		zbuf = buf;
  	else {

  		zbuf = malloc(GZIP_IOBUF_SIZE);

  		len = 0;
  	}
  	if (!zbuf) {
  		error("Out of memory while allocating input buffer");
  		goto gunzip_nomem2;
  	}
  
  	strm = malloc(sizeof(*strm));
  	if (strm == NULL) {
  		error("Out of memory while allocating z_stream");
  		goto gunzip_nomem3;
  	}
  
  	strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :

  #ifdef CONFIG_ZLIB_DFLTCC
  	/* Always allocate the full workspace for DFLTCC */
  				 zlib_inflate_workspacesize());
  #else

  				 sizeof(struct inflate_state));

  #endif

  	if (strm->workspace == NULL) {
  		error("Out of memory while allocating workspace");
  		goto gunzip_nomem4;
  	}

  	if (!fill)
  		fill = nofill;

  	if (len == 0)

  		len = fill(zbuf, GZIP_IOBUF_SIZE);

  
  	/* verify the gzip header */
  	if (len < 10 ||
  	   zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
  		if (pos)
  			*pos = 0;
  		error("Not a gzip file");
  		goto gunzip_5;
  	}
  
  	/* skip over gzip header (1f,8b,08... 10 bytes total +
  	 * possible asciz filename)
  	 */
  	strm->next_in = zbuf + 10;

  	strm->avail_in = len - 10;

  	/* skip over asciz filename */
  	if (zbuf[3] & 0x8) {

  		do {
  			/*
  			 * If the filename doesn't fit into the buffer,
  			 * the file is very probably corrupt. Don't try
  			 * to read more data.
  			 */
  			if (strm->avail_in == 0) {
  				error("header error");
  				goto gunzip_5;
  			}
  			--strm->avail_in;
  		} while (*strm->next_in++);

  	}

  
  	strm->next_out = out_buf;
  	strm->avail_out = out_len;
  
  	rc = zlib_inflateInit2(strm, -MAX_WBITS);

  #ifdef CONFIG_ZLIB_DFLTCC
  	/* Always keep the window for DFLTCC */
  #else

  	if (!flush) {
  		WS(strm)->inflate_state.wsize = 0;
  		WS(strm)->inflate_state.window = NULL;
  	}

  #endif

  
  	while (rc == Z_OK) {
  		if (strm->avail_in == 0) {
  			/* TODO: handle case where both pos and fill are set */

  			len = fill(zbuf, GZIP_IOBUF_SIZE);

  			if (len < 0) {
  				rc = -1;
  				error("read error");
  				break;
  			}
  			strm->next_in = zbuf;
  			strm->avail_in = len;
  		}
  		rc = zlib_inflate(strm, 0);
  
  		/* Write any data generated */
  		if (flush && strm->next_out > out_buf) {

  			long l = strm->next_out - out_buf;

  			if (l != flush(out_buf, l)) {
  				rc = -1;
  				error("write error");
  				break;
  			}
  			strm->next_out = out_buf;
  			strm->avail_out = out_len;
  		}
  
  		/* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */
  		if (rc == Z_STREAM_END) {
  			rc = 0;
  			break;
  		} else if (rc != Z_OK) {
  			error("uncompression error");
  			rc = -1;
  		}
  	}
  
  	zlib_inflateEnd(strm);
  	if (pos)
  		/* add + 8 to skip over trailer */
  		*pos = strm->next_in - zbuf+8;
  
  gunzip_5:
  	free(strm->workspace);
  gunzip_nomem4:
  	free(strm);
  gunzip_nomem3:
  	if (!buf)
  		free(zbuf);
  gunzip_nomem2:
  	if (flush)
  		free(out_buf);
  gunzip_nomem1:
  	return rc; /* returns Z_OK (0) if successful */
  }

  #ifndef PREBOOT
  STATIC int INIT gunzip(unsigned char *buf, long len,
  		       long (*fill)(void*, unsigned long),
  		       long (*flush)(void*, unsigned long),
  		       unsigned char *out_buf,
  		       long *pos,
  		       void (*error)(char *x))
  {
  	return __gunzip(buf, len, fill, flush, out_buf, 0, pos, error);
  }
  #else
  STATIC int INIT __decompress(unsigned char *buf, long len,
  			   long (*fill)(void*, unsigned long),
  			   long (*flush)(void*, unsigned long),
  			   unsigned char *out_buf, long out_len,
  			   long *pos,
  			   void (*error)(char *x))
  {
  	return __gunzip(buf, len, fill, flush, out_buf, out_len, pos, error);
  }
  #endif