Commit f4ae17aa [MIPS: mm: Use scratch for
PGD when !CONFIG_MIPS_PGD_C0_CONTEXT] broke microMIPS kernel builds. This
patch refactors that code similar to what was done for the 'clear_page'
and 'copy_page' functions.
Signed-off-by: NSteven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6744/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Allow usage of scratch register for current pgd even when
MIPS_PGD_C0_CONTEXT is not configured. MIPS_PGD_C0_CONTEXT is set
for 64r2 platforms to indicate availability of Xcontext for saving
cpuid, thus freeing Context to be used for saving PGD. This option
was also tied to using a scratch register for storing PGD.

This commit will allow usage of scratch register to store the current
pgd if one can be allocated for the platform, even when
MIPS_PGD_C0_CONTEXT is not set. The cpuid will be kept in the CP0
Context register in this case.

The code to store the current pgd for the TLB miss handler is now
generated in all cases. When scratch register is available, the PGD
is also stored in the scratch register.
Signed-off-by: NJayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: https://patchwork.linux-mips.org/patch/5906/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

tlbmiss_handler_setup_pgd* are only referenced when
CONFIG_MIPS_PGD_C0_CONTEXT is defined.
Signed-off-by: NTony Wu <tung7970@gmail.com>
Cc: Jayachandran C. <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5601/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Prepare of a next patch which will call tlbmiss_handler_setup_pgd on
microMIPS. MicroMIPS complains if the called code s not in the .text
section. To fix this we generate code into space reserved in
arch/mips/mm/tlb-funcs.S

While there, move the rest of the generated functions (handle_tlbl,
handle_tlbs, handle_tlbm) to the same file.
Signed-off-by: NJayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5542/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>