#!/bin/bash

# Generates a 2.6.34.*, 2.6.35.* or 2.6.36* kernel tree with the SRP_CRED_REQ
# patches applied to the ib_srp initiator.

# Adjust this variable such that it points to the directory with
# linux-x.y.z.tar.bz2 and patch-x.y.z.p.bz2 files on your system
TARBALLDIR=/home/bart/software/downloads

# Local functions

usage() {
  echo "$0 <kernel-version>"
}

# Argument processing

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

if [ "${1#[0-9]*.[0-9]*.[0-9]*.[0-9]*}" != "$1" ]; then
  kernel_version="${1%.[0-9]*}"
  patch_level="${1#${kernel_version}.}"
else
  kernel_version="$1"
fi

# Actual kernel source generation

if [ -e linux-${kernel_version} -o -e linux-$1 ]; then
  echo "Error: directoy not clean."
  exit 1
fi

echo "Extracting kernel sources ..."
tar xaf $TARBALLDIR/linux-${kernel_version}.tar.bz2 || exit $?
if [ "${patch_level}" != "" ]; then
  mv -i linux-${kernel_version} linux-$1 || exit $?
fi
cd linux-$1 || exit $?

if [ "${patch_level}" != "" ]; then
  patchfile="patch-${kernel_version}.${patch_level}"
  echo "Applying ${patchfile} ..."
  bzip2 -cd <${TARBALLDIR}/${patchfile}.bz2 | \
    patch -p1 -s
fi
if [ "${kernel_version}" "<" "2.6.36" ]; then
  # IB/srp: Use print_hex_dump()
  # IB/srp: Make receive buffer handling more robust
  # IB/srp: Export req_lim via sysfs
  for commit in \
    7a7008110b94dfaa90db4b0cc5b0c3f964c80506 \
    c996bb47bb419b7c2f75499e11750142775e5da9 \
    89de74866b846cc48780fda3de7fd223296aaca9
  do
    echo "Applying patch $commit ..."
    url="http://git.kernel.org/?p=linux/kernel/git/roland/infiniband.git;a=patch;h=$commit"
    wget -O- -q "$url" | \
      awk 'BEGIN{h=1}h==0{print}/^diff /{h=0}' | \
      patch -p1 -s
  done
fi
# IB/srp: Preparation for transmit ring response allocation
# IB/srp: Implement SRP_CRED_REQ and SRP_AER_REQ
# IB/srp: Reduce number of BUSY conditions
# IB/srp: use multiple CPU cores more effectively
for p in \
  119771 \
  119772 \
  119773 \
  116774
do
  echo "Applying patch $p ..."
  url="https://patchwork.kernel.org/patch/$p/raw/"
  wget -O- -q "$url" | patch -p1 -s
done