#!/bin/bash

############################################################################
#
# Script for converting the SCST source tree as it exists in the Subversion
# repository to a Linux kernel patch.
#
# Copyright (C) 2008-2020 Bart Van Assche <bvanassche@acm.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation, version 2
# of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
############################################################################

########################
# Function definitions #
########################

# shellcheck source=./kernel-functions
source "$(dirname "$0")/kernel-functions"

function usage {
  echo "Usage: $0 [-d] [-h] [-m] [-n] [-p <dir>] [-s] [-u] <kernel version>"
  echo "where: "
  echo "        -d - enable patch specialization debugging"
  echo "        -h - show this text"
  echo "        -m - add mpt target driver"
  echo "        -n - do not delete code disabled via preprocessor statements"
  echo "        -p - generate multiple patches instead of one big patch into"\
       "the specified directory."
  echo "        -s - disable patch specialization."
  echo "        -u - enables #define GENERATING_UPSTREAM_PATCH."
}

# Convert an existing patch.
# $1: path of patch to be added.
# $2: path in kernel tree of file to be patched.
function add_patch {
  if [ ! -e "$1" ]; then
    echo "Error: could not find $1." >&2
    exit 1
  fi

  sed -e "s:^--- [^ ]*:--- linux-${kver}/$2:" \
      -e "s:^+++ [^ ]*:+++ linux-${kver}/$2:" \
      < "$1"
}

# Generate a patch for a file to be added to the kernel source tree, and strip
# trailing whitespace from C source files while converting the file to patch
# format.
# $1: path of file to be added.
# $2: path in kernel tree where file should be added.
function add_file {
  local a b

  if [ ! -e "$1" ]; then
    echo "Error: could not find $1." >&2
    exit 1
  fi

  # Only include files that were not generated by the build process
  # -- skip *.mod.c.
  if [ "$1" = "${1%.mod.c}" ] && [ "$1" ]; then
    cat <<EOF
diff -uprN linux-${kver}/$2 linux-${kver}/$2
--- linux-${kver}/$2
+++ linux-${kver}/$2
@@ -0,0 +1,$(wc -l "$1" | { read -r a b; echo "$a"; echo "$b" >/dev/null; }) @@
EOF
    # Insert a '+'-sign at the start of each line.
    sed -e 's/^/+/' < "$1" | \
    if [ "${replace_sbug_by_bug}" = "true" ]; then
      sed -e 's/sBUG(\([^)]*\)/BUG(\1/g' -e 's/sBUG_ON(\([^)]*\)/BUG_ON(\1/g'
    else
      cat
    fi \
    |  \
    if [ "${2%.[ch]}" != "$2" ]; then
      # Make sure that labels (goto-targets) are left-aligned.
      sed -e 's/^ \([^ ]*:\)$/\1/'
    else
      cat
    fi
  fi
}

function add_empty_file {
  cat <<EOF
diff -uprN linux-${kver}/$1 linux-${kver}/$1
--- linux-${kver}/$1
+++ linux-${kver}/$1
@@ -0,0 +1,1 @@
+
EOF
}

# Run the script specialize_patch with appropriate options on the patch
# passed via stdin and send the specialized patch to stdout.
function specialize_patch {
  local ao
  set -- ${1//^/ }
  local kver=$1
  local distro=$2
  local release=$3
  set -- ${release//./ }
  local releasevermajor="$1"
  local releaseverminor="$2"
  case "$distro" in
      CentOS)
	  if [ -n "$releasevermajor" ]; then
	      ao=(
		  -v "RHEL_MAJOR=$releasevermajor"
		  -v "RHEL_MINOR=$releaseverminor"
		  -v "RHEL_RELEASE_CODE=$((releasevermajor * 256 +
					   releaseverminor))"
	      )
	  fi
	  ;;
      UEK)
	  ao=(-v UEK_KABI_RENAME=1)
	  ;;
  esac
  local kver3
  set -- ${kver//[.-]/ }
  if [ -n "$3" ]; then
      kver3=$1.$2.$3
  else
      kver3=$1.$2
  fi
  if [ "${enable_specialize}" = "true" ]; then
    if [ "${generating_upstream_patch}" = "true" ]; then
      scripts/filter-trace-entry-exit
    else
      cat
    fi |
    "$(dirname "$0")/specialize-patch" \
         "${specialize_patch_options[@]}" \
         -v kernel_version="${kver3}" \
         -v SCST_IO_CONTEXT="${scst_io_context}" "${ao[@]}"
  else
    cat
  fi
}

# Read a patch from stdin, specialize it for kernel version ${full_kver}
# and write the output either to stdout or to the file $1 (if not empty),
# depending on the value of the variable ${multiple_patches}.
function process_patch {
  local tmppatch
  if [ "${multiple_patches}" = "true" ]; then
    if [ "$1" != "" ]; then
      if [ -e "${patchdir}/$1" ]; then
        echo "Warning: overwriting ${patchdir}/$1"
      fi
      tmppatch="$(/bin/mktemp)"
      (
        specialize_patch "${full_kver}"
      ) >"${tmppatch}"
      touch "${tmppatch}"
      {
        if [ -e /usr/bin/diffstat ]; then
          awk 'BEGIN{h=1}/^diff/{h=0}/^---/{h=0}h!=0{print}' < "${tmppatch}"
          echo "---"
          diffstat "${tmppatch}"
          echo ""
          awk 'BEGIN{h=1}/^diff/{h=0}/^---/{h=0}h==0{print}' < "${tmppatch}"
        fi
      } \
        > "${patchdir}/$(basename "$1")"
      rm -f "${tmppatch}"
    else
      # echo "Discarded $(wc -l) lines."
      true
    fi
  else
    specialize_patch "${full_kver}"
  fi
}

# Returns 0 (true) if SCST core file "$1" should be added in a separate patch,
# and 1 (false) if not.
function in_separate_patch {
  echo "${source_files_in_separate_patch}" | grep -qE "^$1 | $1 | $1\$|^$1\$"
}


#########################
# Argument verification #
#########################

debug_specialize="false"
enable_specialize="true"
generating_upstream_patch="false"
multiple_patches="false"
patchdir=""
replace_sbug_by_bug="true"
specialize_patch_options=(-v "delete_disabled_code=1")
srpt="true"

if [ ! -e scst ] || [ ! -e iscsi-scst ] || [ ! -e srpt ] ||
       [ ! -e scst_local ]; then
  echo "Please run this script from inside the SCST subversion source tree."
  exit 1
fi

# shellcheck disable=SC2046
set -- $(/usr/bin/getopt dhlmnp:su "$@")
while [ "$1" != "${1#-}" ]
do
  case "$1" in
    '-d') debug_specialize="true"; shift;;
    '-h') usage; exit 1;;
    '-l') shift;;
    '-n') specialize_patch_options=(-v "blank_deleted_code=1")
          shift
          ;;
    '-p') multiple_patches="true"; patchdir="$2"; shift; shift;;
    '-s') enable_specialize="false"; shift;;
    '-u') generating_upstream_patch="true"; shift;;
    '--') shift;;
    *)    usage; exit 1;;
  esac
done

if [ $# != 1 ]; then
  usage
  exit 1
fi

# Strip patch level from the kernel version number.
full_kver="$1"
kver="$(kernel_version "$1")"

# Include fcst in the patch for kernel versions 2.6.33 and later.
if kernel_version_le "2.6.37" "${kver}"; then
  include_fcst="true"
else
  include_fcst="false"
fi

# See also commit 89d9a567952b ("[SCSI] add support for per-host cmd pools";
# v3.15).
if kernel_version_lt "$kver" 3.15; then
    qla2x00t="true"
    qla2x00t_32gbit="false"
else
    qla2x00t="false"
    qla2x00t_32gbit="true"
fi

if [ -e "scst/kernel/in-tree/Makefile.scst-${kver}" ]; then
  scst_makefile="Makefile.scst-${kver}"
else
  scst_makefile="Makefile.scst"
fi

# Make sure that for kernel 2.6.26 and later the line
# "#define CONFIG_SCST_PROC" is removed from scst/include/scst.h.
if grep -qw scst_sysfs scst/kernel/in-tree/${scst_makefile} \
   || [ "${generating_upstream_patch}" = "true" ];
then
  specialize_patch_options+=(-v "config_scst_proc_undefined=1")
else
  include_proc_impl="true"
fi
if [ "${debug_specialize}" = "true" ]; then
  specialize_patch_options+=(-v "debug=1")
fi
if [ "${generating_upstream_patch}" = "true" ]; then
  specialize_patch_options+=(-v "generating_upstream_patch_defined=1"
			     -v "config_tcp_zero_copy_transfer_completion_notification_undefined=1")
fi

if [ "${multiple_patches}" = "true" ]; then
  if [ -e "${patchdir}" ]; then
    echo "Patch output directory ${patchdir} already exists."
  fi
  mkdir -p "${patchdir}"
  if [ ! -d "${patchdir}" ]; then
    echo "Error: ${patchdir} is not a directory."
  fi
fi


####################
# Patch Generation #
####################

for f in fcst/linux-patches/series-"${kver}"*
do
   if [ -e "$f" ]; then
       fcst_patch_series="$f"
   fi
done

# General kernel patches.

scst_io_context=0

scst_03_public_headers="scst/include/scst.h scst/include/scst_const.h \
scst/include/scst_event.h scst/include/backport.h"
scst_04_main="scst/src/scst_main.c scst/src/scst_module.c scst/src/scst_priv.h \
scst/src/scst_copy_mgr.c scst/src/scst_dlm.c scst/src/scst_dlm.h \
scst/src/scst_event.c scst/src/scst_no_dlm.c"
scst_05_targ="scst/src/scst_targ.c scst/src/scst_local_cmd.c \
scst/src/scst_local_cmd.h"
scst_06_lib="scst/src/scst_lib.c"
scst_07_pres="scst/src/scst_pres.h scst/src/scst_pres.c"
scst_08_sysfs="scst/src/scst_sysfs.c"
scst_09_debug="scst/include/scst_debug.h scst/src/scst_debug.c"
scst_proc="scst/src/scst_proc.c"
scst_10_sgv="scst/include/scst_sgv.h scst/src/scst_mem.h scst/src/scst_mem.c doc/scst_pg.sgml"
scst_user="scst/include/scst_user.h scst/src/dev_handlers/scst_user.c"
scst_13_vdisk="scst/src/dev_handlers/scst_vdisk.c"
scst_14_tg="scst/src/scst_tg.c"
separate_patches="scst_03_public_headers scst_04_main scst_05_targ scst_06_lib scst_07_pres scst_08_sysfs scst_09_debug scst_10_sgv scst_user scst_13_vdisk scst_14_tg"

# Suppress shellcheck warnings about unused variables.
echo "$scst_03_public_headers $scst_04_main $scst_05_targ $scst_06_lib $scst_07_pres $scst_08_sysfs $scst_09_debug $scst_proc $scst_10_sgv $scst_user $scst_13_vdisk $scst_14_tg" >/dev/null

if [ "$include_proc_impl" = "true" ]; then
  separate_patches+=" scst_proc"
fi
source_files_in_separate_patch=""
for s in ${separate_patches}
do
  source_files_in_separate_patch+=" $(set | \
                    sed -n -e "s/^$s='\(.*\)'$/\1/p" -e "s/^$s=\(.*\)$/\1/p")"
done


# Directory drivers/

(
if [ -e "scst/kernel/in-tree/Kconfig.drivers.Linux-${kver}.patch" ]; then
  add_patch "scst/kernel/in-tree/Kconfig.drivers.Linux-${kver}.patch" \
            "drivers/Kconfig"
else
  add_patch "scst/kernel/in-tree/Kconfig.drivers.Linux.patch" \
            "drivers/Kconfig"
fi

if [ "${full_kver#2.6.32-}" = "${full_kver}" ] &&
       [ -e "scst/kernel/in-tree/Makefile.drivers.Linux-${kver}.patch" ]; then
  add_patch "scst/kernel/in-tree/Makefile.drivers.Linux-${kver}.patch"\
            "drivers/Makefile"
else
  add_patch "scst/kernel/in-tree/Makefile.drivers.Linux.patch"\
            "drivers/Makefile"
fi
) \
| process_patch "scst_01_drivers_kbuild.diff"


# Directory drivers/scst/

(
tmpdir="/tmp/scst-$$"
mkdir -p "${tmpdir}"

tmp_Kconfig="${tmpdir}/Kconfig.scst-${kver}"
# shellcheck disable=SC2002
cat "scst/kernel/in-tree/Kconfig.scst" | \
if [ "${include_fcst}" = true ]; then
  cat
else
  grep -v '^source "drivers/scst/fcst/Kconfig"$'
fi >"${tmp_Kconfig}"
add_file "${tmp_Kconfig}" "drivers/scst/Kconfig"

tmp_Makefile="${tmpdir}/${scst_makefile}"
# shellcheck disable=SC2002
cat "scst/kernel/in-tree/${scst_makefile}" | \
if [ "$include_proc_impl" != "true" ]; then
  grep -v 'scst_proc'
else
  cat
fi | \
  if [ "${include_fcst}" = true ] && [ "${kver}" != "2.6.37" ] &&
	 [ "${kver}" != "2.6.38" ]; then
  cat
else
  sed -e 's: fcst/* : :'
fi >"$tmp_Makefile"
add_file "$tmp_Makefile" "drivers/scst/Makefile"

rm -rf "${tmpdir}"
) \
| process_patch "scst_02_scst_kbuild.diff"

for s in ${separate_patches}
do
  {
    for f in $(eval 'echo "$'"{$s}"'"')
    do
      if [ "${f#scst/include}" != "${f}" ]; then
	add_file "${f}" "include/scst/${f#scst/include/}"
      elif [ "${f#doc}" != "${f}" ]; then
	add_file "${f}" "Documentation/scst/${f#doc/}"
      else
	add_file "${f}" "drivers/scst/${f#scst/src/}"
      fi
    done
    if grep -q /scst_itf_ver.h scst/src/Makefile &&
       [ "$s" = "scst_03_public_headers" ]; then
      tmp_itf_ver="$(mktemp /tmp/scst-itf-ver.h.XXXXXXXXXX)"
      cat <<"EOF" >"$tmp_itf_ver"
/* Autogenerated, don't edit */

#define SCST_INTF_VER "SCST_INTF_VER"
#define SCST_CONST_INTF_VER "SCST_CONST_INTF_VER"
#define DEV_USER_INTF_VER "DEV_USER_INTF_VER"
EOF
      add_file "$tmp_itf_ver" "include/scst/scst_itf_ver.h"
      rm -f "$tmp_itf_ver"
    fi
  } |
  process_patch "${s}.diff"
done

{
  if [ -e scst/README_in-tree ]; then
    add_file "scst/README_in-tree" "Documentation/scst/README.scst"
  fi
  add_file "scst/SysfsRules" "Documentation/scst/SysfsRules"
} | process_patch "scst_11_core_doc.diff"


# Directory drivers/scst/dev_handlers/
if [ -e "scst/kernel/in-tree/Makefile.dev_handlers-${kver}" ]
then
  add_file "scst/kernel/in-tree/Makefile.dev_handlers-${kver}" \
           "drivers/scst/dev_handlers/Makefile" \
  | process_patch "scst_11_dev_handlers_makefile.diff"
else
  add_file "scst/kernel/in-tree/Makefile.dev_handlers" \
           "drivers/scst/dev_handlers/Makefile" \
  | process_patch "scst_11_dev_handlers_makefile.diff"
fi

for f in scst/src/dev_handlers/*.[ch]; do
  [ -e "$f" ] || continue
  if ! in_separate_patch "${f}"; then
    add_file "${f}" "drivers/scst/dev_handlers/${f#scst/src/dev_handlers/}"
  fi
done \
| process_patch "scst_14_passthrough.diff"


# Directory drivers/scst/fcst/

if [ "${include_fcst}" = true ]; then
  if [ -e "${fcst_patch_series}" ]; then
    grep -v '^#' "${fcst_patch_series}" |
      while read -r f; do
        cat "fcst/linux-patches/${f}"
      done
  fi

  for f in fcst/Kbuild fcst/Makefile_in-tree; do
    [ -e "$f" ] && add_file "$f" "drivers/scst/fcst/Makefile"
  done

  add_file "fcst/Kconfig" "drivers/scst/fcst/Kconfig"

  for f in fcst/*.[ch]; do
    [ -e "$f" ] || continue
    add_file "${f}" "drivers/scst/fcst/${f#fcst/}"
  done
fi \
| process_patch "fcst.diff"

add_file "fcst/README" "Documentation/scst/README.fcst" \
| process_patch "fcst-doc.diff"


# Directory drivers/scst/iscsi-scst/

# Make sure the file iscsi-scst/iscsi_scst_itf_ver.h is up to date.
make -s -C iscsi-scst include/iscsi_scst_itf_ver.h

(
for f in iscsi-scst/include/*h; do
    [ -e "$f" ] || continue	
    case "${f}" in
      "iscsi-scst/include/iscsi_scst_itf_ver.h")
          ;;
      "iscsi-scst/include/iscsit_transport.h")
          add_file "${f}" "include/scst/${f#iscsi-scst/include/}"
          ;;
      *)
          add_file "${f}" "include/scst/${f#iscsi-scst/include/}"
          ;;
    esac
done

add_file "iscsi-scst/include/iscsi_scst_itf_ver.h" "include/scst/iscsi_scst_itf_ver.h"

add_file "iscsi-scst/kernel/Makefile.in-kernel" \
         "drivers/scst/iscsi-scst/Makefile"

add_file "iscsi-scst/kernel/Kconfig"  "drivers/scst/iscsi-scst/Kconfig"

for f in iscsi-scst/kernel/*.[ch]; do
  [ -e "$f" ] || continue
  add_file "${f}" "drivers/scst/iscsi-scst/${f#iscsi-scst/kernel/}"
done

for f in iscsi-scst/kernel/isert-scst/*.[ch]; do
  [ -e "$f" ] || continue
  add_file "${f}" "drivers/scst/iscsi-scst/isert-scst/${f#iscsi-scst/kernel/isert-scst/}"
done
add_file "iscsi-scst/kernel/isert-scst/Makefile.in-kernel" "drivers/scst/iscsi-scst/isert-scst/Makefile"
add_file "iscsi-scst/kernel/isert-scst/Kconfig" "drivers/scst/iscsi-scst/isert-scst/Kconfig"
) \
| process_patch "iscsi-scst.diff"

add_file "iscsi-scst/README_in-tree" "Documentation/scst/README.iscsi" \
| process_patch "iscsi-scst-doc.diff"


# Directory drivers/scsi/qla2xxx/

if [ "${qla2x00t}" = "true" ]; then

  ( cd qla2x00t && "$PWD/generate-in-tree-patches" "$1" ) || exit $?

  for f in qla2x00t/in-tree-patches/"$1"/*.patch; do
    [ -e "$f" ] || continue
    g="${f#qla2x00t/in-tree-patches/$1/}"
    g="${g%.patch}"
    add_patch "${f}" "drivers/scsi/qla2xxx/${g}"
  done

  add_file "qla2x00t/qla2x_tgt.h" \
           "drivers/scsi/qla2xxx/qla2x_tgt.h"

  add_file "qla2x00t/qla2x_tgt_def.h" \
           "drivers/scsi/qla2xxx/qla2x_tgt_def.h"

  for f in qla2x00t/qla2x00-target/*.[ch]; do
    [ -e "$f" ] &&
    add_file "${f}" "drivers/scsi/qla2xxx/${f#qla2x00t/qla2x00-target/}"
  done

  add_file "qla2x00t/qla2x00-target/README" \
           "Documentation/scst/README.qla2x00t" \
  | process_patch "qla2x00t-doc.diff"

elif [ "${qla2x00t_32gbit}" = "true" ]; then

  ( cd qla2x00t-32gbit && "$PWD/generate-in-tree-patches" "$1" ) || exit $?

  for f in qla2x00t-32gbit/in-tree-patches/"$1"/*.patch; do
    [ -e "$f" ] || continue
    g="${f#qla2x00t-32gbit/in-tree-patches/$1/}"
    g="${g%.patch}"
    if [ "$g" = "qla.h" ]; then
	add_patch "${f}" "include/trace/events/${g}"
    else
	add_patch "${f}" "drivers/scsi/qla2xxx/${g}"
    fi
  done

  for f in qla2x00t-32gbit/qla2x00-target/*.[ch]; do
    [ -e "$f" ] || continue
    add_file "${f}" "drivers/scsi/qla2xxx/${f#qla2x00t-32gbit/qla2x00-target/}"
  done

  add_file "qla2x00t-32gbit/qla2x00-target/README" \
           "Documentation/scst/README.qla2x00t" \
  | process_patch "qla2x00t-doc.diff"
    
fi \
| process_patch "qla2x00t.diff"


# Directory drivers/scst/srpt

{

cat <<EOF
This patch adds the kernel module ib_srpt, which is a SCSI RDMA Protocol (SRP)
target implementation. This driver uses the InfiniBand stack and the SCST core.

It is a high performance driver capable of handling 600K+ 4K random write
IOPS by a single target as well as 2.5+ GB/s sequential throughput over
a single QDR IB port.

It was originally developed by Vu Pham (Mellanox) and has been optimized by
Bart Van Assche.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Vu Pham <vu@mellanox.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: David Dillow <dillowda@ornl.gov>
EOF
if [ "$srpt" = "true" ]; then

  add_file  "srpt/README_in-tree"         "Documentation/scst/README.srpt"

  add_file  "srpt/src/Kconfig"            "drivers/scst/srpt/Kconfig"

  add_file  "srpt/src/Makefile.in_kernel" "drivers/scst/srpt/Makefile"

  for f in srpt/src/*.[ch]; do
    [ -e "$f" ] || continue
    add_file "${f}" "drivers/scst/srpt/${f#srpt/src/}"
  done

else

  add_empty_file "drivers/scst/srpt/Kconfig"

  add_empty_file "drivers/scst/srpt/Makefile"

fi \
} | process_patch "scst_17_srpt.diff"


# Directory drivers/scst/scst_local

(
  add_file "scst_local/README"          "Documentation/scst/README.scst_local"

  add_file "scst_local/in-tree/Kconfig" "drivers/scst/scst_local/Kconfig"

  if [ -e "scst_local/in-tree/Makefile-${kver}" ]; then
    add_file "scst_local/in-tree/Makefile-${kver}" "drivers/scst/scst_local/Makefile"
  else
    add_file "scst_local/in-tree/Makefile" "drivers/scst/scst_local/Makefile"
  fi

  add_file "scst_local/scst_local.c" "drivers/scst/scst_local/scst_local.c"
) \
| process_patch "scst_16_local.diff"


# Directory drivers/scsi/ibmvstgt

{
  ( cd ibmvstgt 2>/dev/null && ./generate-in-tree-patches "${kver}" ) &&
  if [ -e "ibmvstgt/in-tree-patches/${kver}" ]; then
    if [ "${multiple_patches}" = "true" ]; then
      cat <<EOF
[SCSI] ibmvstgt: Port from tgt to SCST

The ibmvstgt and libsrp kernel modules as included in the 2.6.37 kernel are
based on the tgt SCSI target framework. Both kernel modules need the scsi_tgt
kernel module and the tgtd user space process in order to function
properly. This patch modifies the ibmvstgt and libsrp kernel modules such that
both use the SCST storage target framework instead of tgt. As a result,
neither the scsi_tgt kernel module nor the tgtd user space process are any
more necessary when using the ibmvstgt driver.

This patch introduces one backwards-incompatible change, namely that the path
of the ibmvstgt sysfs attributes is modified. This change is unavoidable
because this patch dissociates ibmvstgt SRP sessions from a SCSI host
instance.  Since the user space STGT driver ibmvio was the only user of
these attributes, that shouldn't be an issue.

Changes in ibmvstgt compared to kernel 2.6.36:
- Increased maximum data size for a single SRP command from 128 KB to 64 MB
  such that an initiator is not forced to split large transfers into
  multiple SCSI commands.
- The maximum RDMA transfer size supported by a single H_COPY_RDMA call is
  queried at driver initialization time from the open firmware tree / larger
  transfers than 128 KB are now supported too.
- If DMA mapping fails while handling a READ or WRITE command, the offending
  command is retried until the associated data has been transferred instead of
  reporting to the ibmvscsi client that the SCSI command failed.
- VSCSI command/response queue: one element has been reserved for management
  datagrams since these fall outside the SRP credit mechanism. Added a compile-
  time check whether the size of this queue is a power of two.
- Fixed a race condition which in theory could have caused the VSCSI receive
  queue to overflow: srp_iu_put() is now invoked before a response is sent back
  to the initiator instead of after.
- Moved enum iue_flags from libsrp to ibmvstgt because it is ibmvstgt-specific.
- Removed a variable that was modified but never read from ibmvstgt_rdma().
- ibmvstgt_probe(): changed the datatype of the variable "dma" from
  unsigned * into const unsigned * such that a cast could be removed.
- Fixed all compiler and sparse warnings (C=2 CF=-D__CHECK_ENDIAN__).

Changes in libsrp compared to kernel 2.6.36:
- Renamed vscsis_data_length() into srp_data_length() and exported
  this function.
- All error messages reported via printk() do now have prefix KERN_ERR.
- modified srp_target_alloc() and srp_target_free() such that the
  driver-private data reflects whether or not target data has been allocated.
  This change was necessary to avoid that ibmvstgt_remove() triggers a
  NULL-pointer dereference if ibmvstgt_probe() failed.
- srp_transfer_data(): All three return statements related to DMA mapping
  failure do now return -ENOMEM instead of 0, -EIO and -ENOMEM.
- srp_direct_data(): Removed the ext_desc argument since not used.
- srp_direct_data() and srp_indirect_data(): Use DMA_TO/FROM_DEVICE
  instead of DMA_BIDIRECTIONAL for the buffers mapped for transferring data
  via DMA.
- struct srp_target: eliminated the information unit linked list and also the
  V_FLYING flag since both were duplicating information managed by the SCST
  core.
- Fixed all compiler and sparse warnings (C=2 CF=-D__CHECK_ENDIAN__).

Tests performed on a backport to kernel version 2.6.18 of this driver with a
Linux initiator system:
- Verified that the kernel module ibmvstgt loads and initializes successfully
  and also that the client connects after loading.
- Verified that all virtual disks configured in scst_vdisk were discovered by
  the client after rescanning the SCSI bus.
- Verified that after unloading and reloading ibmvstgt and after client
  recovery that the initiator devices were functioning normally.
- Verified that after a client reboot ibmvscsic reconnected with the target
  and that the target devices were again usable.
- Performed IO stress testing on the device.
- Verified that SCSI task abortion works correctly.
- Performed basic I/O performance testing. With a RAM disk as target linear
  direct I/O throughput was above 2 GB/s and a random I/O test resulted in
  about 30000 IOPS for all block sizes between 512 bytes and 16 KB.
  Both initiator and target were dual core POWER6 LPAR systems.

Note: ibmvstgt is the only user of libsrp.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Fujita Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>

EOF
    fi
    for f in \
      drivers/scsi/ibmvscsi/ibmvstgt.c \
      drivers/scsi/libsrp.c \
      include/scsi/libsrp.h \
      include/scsi/srp.h
    do
      patch="ibmvstgt/in-tree-patches/${kver}/$(basename $f).patch"
      if [ -e "${patch}" ]; then
        add_patch "${patch}" $f
      fi
    done
    add_file "ibmvstgt/README.sysfs" "Documentation/powerpc/ibmvstgt.txt"
  fi
} \
| process_patch "scst_18_ibmvstgt.diff"

{
  ( cd ibmvstgt 2>/dev/null && ./generate-in-tree-patches "${kver}" ) &&
  if [ -e "ibmvstgt/in-tree-patches/${kver}" ]; then
    if [ "${multiple_patches}" = "true" ]; then
      cat <<EOF
[SCSI] tgt: Removal

Because of the conversion of the ibmvstgt driver from tgt to SCST, and because
the ibmvstgt driver was the only user of scsi_tgt, the scsi_tgt kernel module,
the CONFIG_SCSI_TGT, CONFIG_SCSI_SRP_TGT_ATTRS and CONFIG_SCSI_FC_TGT_ATTRS
kbuild variable, the scsi_host_template member variables transfer_response,
supportedmode and active_mode and the constants MODE_UNKNOWN, MODE_INITIATOR
and MODE_TARGET are no longer needed.

Note: this patch applies cleanly on a 2.6.35 kernel tree. The patch tool
however complains about the defconfig changes when trying to apply this patch
on a 2.6.36 kernel tree.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>

EOF
    fi
    for f in \
      arch/arm/configs/at572d940hfek_defconfig \
      arch/arm/configs/cam60_defconfig \
      arch/arm/configs/s3c2410_defconfig \
      arch/m68k/configs/amiga_defconfig \
      arch/m68k/configs/apollo_defconfig \
      arch/m68k/configs/atari_defconfig \
      arch/m68k/configs/bvme6000_defconfig \
      arch/m68k/configs/hp300_defconfig \
      arch/m68k/configs/mac_defconfig \
      arch/m68k/configs/multi_defconfig \
      arch/m68k/configs/mvme147_defconfig \
      arch/m68k/configs/mvme16x_defconfig \
      arch/m68k/configs/q40_defconfig \
      arch/m68k/configs/sun3_defconfig \
      arch/m68k/configs/sun3x_defconfig \
      arch/mips/configs/bcm47xx_defconfig \
      arch/mips/configs/decstation_defconfig \
      arch/mips/configs/ip22_defconfig \
      arch/mips/configs/ip27_defconfig \
      arch/mips/configs/ip32_defconfig \
      arch/mips/configs/jazz_defconfig \
      arch/mips/configs/malta_defconfig \
      arch/mips/configs/markeins_defconfig \
      arch/mips/configs/pnx8550-jbs_defconfig \
      arch/mips/configs/pnx8550-stb810_defconfig \
      arch/mips/configs/rm200_defconfig \
      arch/mips/configs/tb0226_defconfig \
      arch/mips/configs/tb0287_defconfig \
      arch/powerpc/configs/52xx/motionpro_defconfig \
      arch/powerpc/configs/86xx/mpc8610_hpcd_defconfig \
      arch/powerpc/configs/mpc5200_defconfig \
      drivers/scsi/Kconfig \
      drivers/scsi/Makefile \
      drivers/scsi/hosts.c \
      drivers/scsi/scsi_sysfs.c \
      drivers/scsi/scsi_tgt_if.c \
      drivers/scsi/scsi_tgt_lib.c \
      drivers/scsi/scsi_tgt_priv.h \
      drivers/scsi/scsi_transport_fc.c \
      drivers/scsi/scsi_transport_fc_internal.h \
      drivers/scsi/scsi_transport_srp.c \
      drivers/scsi/scsi_transport_srp_internal.h \
      include/scsi/scsi_host.h \
      include/scsi/scsi_tgt.h \
      include/scsi/scsi_tgt_if.h
    do
      add_patch "ibmvstgt/in-tree-patches/${kver}/$(basename $f).patch" $f
    done
  fi
} \
| process_patch "scst_19_scsi_tgt.diff"