[PATCH 3.18 14/39] MIPS: mipsregs.h: Add write_32bit_cp1_register()

Greg Kroah-Hartman
2015-02-09T08:36:51Z

From: James Hogan <james.hogan@imgtec.com>

commit 5e32033e14ca9c7f7341cb383f5a05699b0b5382 upstream.

Add a write_32bit_cp1_register() macro to compliment the
read_32bit_cp1_register() macro. This is to abstract whether .set
hardfloat needs to be used based on GAS_HAS_SET_HARDFLOAT.

The implementation of _read_32bit_cp1_register() .sets mips1 due to
failure of gas v2.19 to assemble cfc1 for Octeon (see commit
25c300030016 ("MIPS: Override assembler target architecture for
octeon.")). I haven't copied this over to _write_32bit_cp1_register() as
I'm uncertain whether it applies to ctc1 too, or whether anybody cares
about that version of binutils any longer.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9172/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/mips/include/asm/mipsregs.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)

--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -1343,12 +1343,27 @@ do { \
__res; \
})

+#define _write_32bit_cp1_register(dest, val, gas_hardfloat) \
+do { \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set reorder \n" \
+ " "STR(gas_hardfloat)" \n" \
+ " ctc1 %0,"STR(dest)" \n" \
+ " .set pop \n" \
+ : : "r" (val)); \
+} while (0)
+
#ifdef GAS_HAS_SET_HARDFLOAT
#define read_32bit_cp1_register(source) \
_read_32bit_cp1_register(source, .set hardfloat)
+#define write_32bit_cp1_register(dest, val) \
+ _write_32bit_cp1_register(dest, val, .set hardfloat)
#else
#define read_32bit_cp1_register(source) \
_read_32bit_cp1_register(source, )
+#define write_32bit_cp1_register(dest, val) \
+ _write_32bit_cp1_register(dest, val, )
#endif

#ifdef HAVE_AS_DSP