These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild  N    ] net-wireless/ieee80211-1.2.15  USE="-debug" 0 kB
[ebuild  N    ] net-wireless/ipw3945-1.2.0  USE="-debug" 230 kB

Total: 2 packages (2 new), Size of downloads: 230 kB

Would you like to merge these packages? [Yes/No] yes
>>> starting parallel fetching

>>> Emerging (1 of 2) net-wireless/ieee80211-1.2.15 to /
 * ieee80211-1.2.15.tgz MD5 ;-) ...                                       [ ok ]
 * ieee80211-1.2.15.tgz RMD160 ;-) ...                                    [ ok ]
 * ieee80211-1.2.15.tgz SHA1 ;-) ...                                      [ ok ]
 * ieee80211-1.2.15.tgz SHA256 ;-) ...                                    [ ok ]
 * ieee80211-1.2.15.tgz size ;-) ...                                      [ ok ]
 * checking ebuild checksums ;-) ...                                      [ ok ]
 * checking auxfile checksums ;-) ...                                     [ ok ]
 * checking miscfile checksums ;-) ...                                    [ ok ]
 * checking ieee80211-1.2.15.tgz ;-) ...                                  [ ok ]
 * Determining the location of the kernel source code
 * Found kernel source directory:
 *     /usr/src/linux
 * Found sources for kernel version:
 *     2.6.20-gentoo
 * Checking for suitable kernel configuration options...                  [ ok ]
>>> Unpacking source...
>>> Unpacking ieee80211-1.2.15.tgz to /var/tmp/portage/net-wireless/ieee80211-1.2.15/work
>>> Source unpacked.
>>> Compiling source in /var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15 ...
 * Preparing ieee80211 module
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_ccmp.c: In function ‘ieee80211_ccmp_aes_encrypt’:
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_ccmp.c:65: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_ccmp.c:66: warning: implicit declaration of function ‘offset_in_page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_ccmp.c:69: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_ccmp.c:73: warning: ‘crypto_cipher_encrypt’ is deprecated (declared at include/linux/crypto.h:820)
make[2]: *** [/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_ccmp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.c: In function ‘prism2_wep_encrypt’:
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.c:169: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.c:170: warning: implicit declaration of function ‘offset_in_page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.c:172: warning: ‘crypto_cipher_encrypt’ is deprecated (declared at include/linux/crypto.h:820)
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.c: In function ‘prism2_wep_decrypt’:
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.c:212: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.c:215: warning: ‘crypto_cipher_decrypt’ is deprecated (declared at include/linux/crypto.h:846)
make[2]: *** [/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_wep.o] Error 1
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c: In function ‘ieee80211_tkip_encrypt’:
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:382: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:383: warning: implicit declaration of function ‘offset_in_page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:385: warning: ‘crypto_cipher_encrypt’ is deprecated (declared at include/linux/crypto.h:820)
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c: In function ‘ieee80211_tkip_decrypt’:
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:477: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:480: warning: ‘crypto_cipher_decrypt’ is deprecated (declared at include/linux/crypto.h:846)
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c: In function ‘michael_mic’:
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:523: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:527: error: invalid use of undefined type ‘struct page’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:531: warning: implicit declaration of function ‘crypto_digest_init’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:532: warning: implicit declaration of function ‘crypto_digest_setkey’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:533: warning: implicit declaration of function ‘crypto_digest_update’
/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.c:534: warning: implicit declaration of function ‘crypto_digest_final’
make[2]: *** [/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15/ieee80211_crypt_tkip.o] Error 1
make[1]: *** [_module_/var/tmp/portage/net-wireless/ieee80211-1.2.15/work/ieee80211-1.2.15] Error 2
make: *** [modules] Error 2

!!! ERROR: net-wireless/ieee80211-1.2.15 failed.
Call stack:
  ebuild.sh, line 1613:   Called dyn_compile
  ebuild.sh, line 970:   Called qa_call 'src_compile'
  environment, line 4081:   Called src_compile
  ebuild.sh, line 1303:   Called linux-mod_src_compile
  linux-mod.eclass, line 510:   Called die

!!! Unable to make  KSRC=/usr/src/linux KSRC_OUTPUT=/usr/src/linux modules.
!!! If you need support, post the topmost build error, and the call stack if relevant.
!!! A complete build log is located at '/var/tmp/portage/net-wireless/ieee80211-1.2.15/temp/build.log'.