// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 2018 Chelsio Communications.  All rights reserved.
 */

#include <linux/zlib.h>

#include "cxgb4.h"
#include "cudbg_if.h"
#include "cudbg_lib_common.h"
#include "cudbg_zlib.h"

static int cudbg_get_compress_hdr(struct cudbg_buffer *pdbg_buff,
      struct cudbg_buffer *pin_buff)
{
 if (pdbg_buff->offset + sizeof(struct cudbg_compress_hdr) >
     pdbg_buff->size)
  return CUDBG_STATUS_NO_MEM;

 pin_buff->data = (char *)pdbg_buff->data + pdbg_buff->offset;
 pin_buff->offset = 0;
 pin_buff->size = sizeof(struct cudbg_compress_hdr);
 pdbg_buff->offset += sizeof(struct cudbg_compress_hdr);
 return 0;
}

int cudbg_compress_buff(struct cudbg_init *pdbg_init,
   struct cudbg_buffer *pin_buff,
   struct cudbg_buffer *pout_buff)
{
 struct cudbg_buffer temp_buff = { 0 };
 struct z_stream_s compress_stream;
 struct cudbg_compress_hdr *c_hdr;
 int rc;

 /* Write compression header to output buffer before compression */
 rc = cudbg_get_compress_hdr(pout_buff, &temp_buff);
 if (rc)
  return rc;

 c_hdr = (struct cudbg_compress_hdr *)temp_buff.data;
 c_hdr->compress_id = CUDBG_ZLIB_COMPRESS_ID;

 memset(&compress_stream, 0, sizeof(struct z_stream_s));
 compress_stream.workspace = pdbg_init->workspace;
 rc = zlib_deflateInit2(&compress_stream, Z_DEFAULT_COMPRESSION,
          Z_DEFLATED, CUDBG_ZLIB_WIN_BITS,
          CUDBG_ZLIB_MEM_LVL, Z_DEFAULT_STRATEGY);
 if (rc != Z_OK)
  return CUDBG_SYSTEM_ERROR;

 compress_stream.next_in = pin_buff->data;
 compress_stream.avail_in = pin_buff->size;
 compress_stream.next_out = pout_buff->data + pout_buff->offset;
 compress_stream.avail_out = pout_buff->size - pout_buff->offset;

 rc = zlib_deflate(&compress_stream, Z_FINISH);
 if (rc != Z_STREAM_END)
  return CUDBG_SYSTEM_ERROR;

 rc = zlib_deflateEnd(&compress_stream);
 if (rc != Z_OK)
  return CUDBG_SYSTEM_ERROR;

 c_hdr->compress_size = compress_stream.total_out;
 c_hdr->decompress_size = pin_buff->size;
 pout_buff->offset += compress_stream.total_out;

 return 0;
}