[MIPS] Add basic SMARTMIPS ASE support

This patch adds trivial support for SMARTMIPS extension. This extension
is currently implemented by 4KS[CD] CPUs.

Basically it saves/restores ACX register, which is part of the SMARTMIPS
ASE, when needed. This patch does *not* add any support for Smartmips MMU
features.

Futhermore this patch does not add explicit support for 4KS[CD] CPUs since
they are respectively mips32 and mips32r2 compliant.  So with the current
processor configuration, a platform that has such CPUs needs to select
both configs:

	CPU_HAS_SMARTMIPS
	SYS_HAS_CPU_MIPS32_R[12]

This is due to the processor configuration which is mixing up all the
architecture variants and the processor types.

The drawback of this, is that we currently pass '-march=mips32' option to
gcc when building a kernel instead of '-march=4ksc' for 4KSC case. This
can lead to a kernel image a little bit bigger than required.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/asm-mips/sigcontext.h b/include/asm-mips/sigcontext.h
index 972947474eb..9ce0607d7a4 100644
--- a/include/asm-mips/sigcontext.h
+++ b/include/asm-mips/sigcontext.h
@@ -23,7 +23,7 @@ struct sigcontext {
         unsigned long long      sc_pc;
         unsigned long long      sc_regs[32];
         unsigned long long      sc_fpregs[32];
-        unsigned int            sc_ownedfp;     /* Unused */
+        unsigned int            sc_acx;         /* Was sc_ownedfp */
         unsigned int            sc_fpc_csr;
         unsigned int            sc_fpc_eir;     /* Unused */
         unsigned int            sc_used_math;
@@ -79,7 +79,7 @@ struct sigcontext32 {
         __u64           sc_pc;
         __u64           sc_regs[32];
         __u64           sc_fpregs[32];
-        __u32           sc_ownedfp;     /* Unused */
+        __u32           sc_acx;         /* Only MIPS32; was sc_ownedfp */
         __u32           sc_fpc_csr;
         __u32           sc_fpc_eir;     /* Unused */
         __u32           sc_used_math;