Enable CONFIG_MIPS_AUTO_PFN_OFFSET for the generic platform, allowing
it to avoid wasted book-keeping for pages with addresses lower than the
physical base address of memory.
This has a minimal impact on kernel text size, with 64r6el_defconfig
gaining 0.1% in size as reported by bloat-o-meter:
add/remove: 4/1 grow/shrink: 345/13 up/down: 9017/-392 (8625)
Function old new delta
pcpu_setup_first_chunk 1444 1780 +336
pcpu_alloc_first_chunk 864 1136 +272
start_kernel 1064 1288 +224
initcall_blacklist 224 372 +148
try_fill_recv 2088 2184 +96
...
Total: Before=8457273, After=8465898, chg +0.10%
The gain for systems with large offsets to physical memory & the ability
to continue using generic kernels on such systems seems well worth this
small cost.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Suggested-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Patchwork: https://patchwork.linux-mips.org/patch/20049/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
0211d49e52