As described this is the main implementaion patch.

2015-08-26  Jiong Wang  <jiong.wang@arm.com>

gcc/
  * configure.ac: Add check for binutils global dynamic tiny code model
  relocation support.
  * configure: Regenerate.
  * config.in: Regenerate.
  * config/aarch64/aarch64.md (tlsgd_tiny): New define_insn.
  * config/aarch64/aarch64-protos.h (aarch64_symbol_type): New
  enumeration SYMBOL_TINY_TLSGD.
  (aarch64_symbol_context): New comment on SYMBOL_TINY_TLSGD.
  * config/aarch64/aarch64.c (aarch64_classify_tls_symbol): Support
  SYMBOL_TINY_TLSGD.
  (aarch64_print_operand): Likewise.
  (aarch64_expand_mov_immediate): Likewise.
  (aarch64_load_symref_appropriately): Likewise.

gcc/testsuite/
  * lib/target-supports.exp (check_effective_target_aarch64_tlsgdtiny):
  New effective check.
  * gcc.target/aarch64/tlsgd_small_1.c: New testcase.
  * gcc.target/aarch64/tlsgd_tiny_1.c: Likewise.

-- 
Regards,
Jiong