[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>
diff --git a/include/asm-mips/stackframe.h b/include/asm-mips/stackframe.h
index 1fae5dc..7afa1fd 100644
--- a/include/asm-mips/stackframe.h
+++ b/include/asm-mips/stackframe.h
@@ -29,16 +29,25 @@
.endm
.macro SAVE_TEMP
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+ mflhxu v1
+ LONG_S v1, PT_LO(sp)
+ mflhxu v1
+ LONG_S v1, PT_HI(sp)
+ mflhxu v1
+ LONG_S v1, PT_ACX(sp)
+#else
mfhi v1
+ LONG_S v1, PT_HI(sp)
+ mflo v1
+ LONG_S v1, PT_LO(sp)
+#endif
#ifdef CONFIG_32BIT
LONG_S $8, PT_R8(sp)
LONG_S $9, PT_R9(sp)
#endif
- LONG_S v1, PT_HI(sp)
- mflo v1
LONG_S $10, PT_R10(sp)
LONG_S $11, PT_R11(sp)
- LONG_S v1, PT_LO(sp)
LONG_S $12, PT_R12(sp)
LONG_S $13, PT_R13(sp)
LONG_S $14, PT_R14(sp)
@@ -182,16 +191,25 @@
.endm
.macro RESTORE_TEMP
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+ LONG_L $24, PT_ACX(sp)
+ mtlhx $24
+ LONG_L $24, PT_HI(sp)
+ mtlhx $24
LONG_L $24, PT_LO(sp)
+ mtlhx $24
+#else
+ LONG_L $24, PT_LO(sp)
+ mtlo $24
+ LONG_L $24, PT_HI(sp)
+ mthi $24
+#endif
#ifdef CONFIG_32BIT
LONG_L $8, PT_R8(sp)
LONG_L $9, PT_R9(sp)
#endif
- mtlo $24
- LONG_L $24, PT_HI(sp)
LONG_L $10, PT_R10(sp)
LONG_L $11, PT_R11(sp)
- mthi $24
LONG_L $12, PT_R12(sp)
LONG_L $13, PT_R13(sp)
LONG_L $14, PT_R14(sp)