A few MIPS fixes for 5.4:

- Build fixes for CONFIG_OPTIMIZE_INLINING=y builds in which the
  compiler may choose not to inline __xchg() & __cmpxchg().

- A build fix for Loongson configurations with GCC 9.x.

- Expose some extra HWCAP bits to indicate support for various
  instruction set extensions to userland.

- Fix bad stack access in firmware handling code for old SNI
  RM200/300/400 machines.
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MIPS: Disable Loongson MMI instructions for kernel build

GCC 9.x automatically enables support for Loongson MMI instructions when
using some -march= flags, and then errors out when -msoft-float is
specified with:

  cc1: error: ‘-mloongson-mmi’ must be used with ‘-mhard-float’

The kernel shouldn't be using these MMI instructions anyway, just as it
doesn't use floating point instructions. Explicitly disable them in
order to fix the build with GCC 9.x.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 3702bba5eb4f ("MIPS: Loongson: Add GCC 4.4 support for Loongson2E")
Fixes: 6f7a251a259e ("MIPS: Loongson: Add basic Loongson 2F support")
Fixes: 5188129b8c9f ("MIPS: Loongson-3: Improve -march option and move it to Platform")
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: stable@vger.kernel.org # v2.6.32+
Cc: linux-mips@vger.kernel.org
2 files changed