MIPS: Correct MIPS I FP context layout

Implement the correct ordering of individual floating-point registers
within double-precision register pairs for the MIPS I FP context, as
required by our FP emulation code and expected by userland talking via
ptrace(2).  Use L.D and S.D assembly macros that do the right thing like
LDC1 and SDC1 from MIPS II up, avoiding the need to mess up with
endianness conditionals.

This in particular fixes the handling of denormals and NaN generation in
Unimplemented Operation emulation traps.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9699/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 32 insertions, 64 deletions

diff --git a/arch/mips/include/asm/asmmacro-32.h b/arch/mips/include/asm/asmmacro-32.h
index cdac7b3eeaf7..8deb906df724 100644
--- a/arch/mips/include/asm/asmmacro-32.h
+++ b/arch/mips/include/asm/asmmacro-32.h
@@ -16,38 +16,22 @@
 	.set push
 	SET_HARDFLOAT
 	cfc1	\tmp,  fcr31
-	swc1	$f0,  THREAD_FPR0_LS64(\thread)
-	swc1	$f1,  THREAD_FPR1_LS64(\thread)
-	swc1	$f2,  THREAD_FPR2_LS64(\thread)
-	swc1	$f3,  THREAD_FPR3_LS64(\thread)
-	swc1	$f4,  THREAD_FPR4_LS64(\thread)
-	swc1	$f5,  THREAD_FPR5_LS64(\thread)
-	swc1	$f6,  THREAD_FPR6_LS64(\thread)
-	swc1	$f7,  THREAD_FPR7_LS64(\thread)
-	swc1	$f8,  THREAD_FPR8_LS64(\thread)
-	swc1	$f9,  THREAD_FPR9_LS64(\thread)
-	swc1	$f10, THREAD_FPR10_LS64(\thread)
-	swc1	$f11, THREAD_FPR11_LS64(\thread)
-	swc1	$f12, THREAD_FPR12_LS64(\thread)
-	swc1	$f13, THREAD_FPR13_LS64(\thread)
-	swc1	$f14, THREAD_FPR14_LS64(\thread)
-	swc1	$f15, THREAD_FPR15_LS64(\thread)
-	swc1	$f16, THREAD_FPR16_LS64(\thread)
-	swc1	$f17, THREAD_FPR17_LS64(\thread)
-	swc1	$f18, THREAD_FPR18_LS64(\thread)
-	swc1	$f19, THREAD_FPR19_LS64(\thread)
-	swc1	$f20, THREAD_FPR20_LS64(\thread)
-	swc1	$f21, THREAD_FPR21_LS64(\thread)
-	swc1	$f22, THREAD_FPR22_LS64(\thread)
-	swc1	$f23, THREAD_FPR23_LS64(\thread)
-	swc1	$f24, THREAD_FPR24_LS64(\thread)
-	swc1	$f25, THREAD_FPR25_LS64(\thread)
-	swc1	$f26, THREAD_FPR26_LS64(\thread)
-	swc1	$f27, THREAD_FPR27_LS64(\thread)
-	swc1	$f28, THREAD_FPR28_LS64(\thread)
-	swc1	$f29, THREAD_FPR29_LS64(\thread)
-	swc1	$f30, THREAD_FPR30_LS64(\thread)
-	swc1	$f31, THREAD_FPR31_LS64(\thread)
+	s.d	$f0,  THREAD_FPR0_LS64(\thread)
+	s.d	$f2,  THREAD_FPR2_LS64(\thread)
+	s.d	$f4,  THREAD_FPR4_LS64(\thread)
+	s.d	$f6,  THREAD_FPR6_LS64(\thread)
+	s.d	$f8,  THREAD_FPR8_LS64(\thread)
+	s.d	$f10, THREAD_FPR10_LS64(\thread)
+	s.d	$f12, THREAD_FPR12_LS64(\thread)
+	s.d	$f14, THREAD_FPR14_LS64(\thread)
+	s.d	$f16, THREAD_FPR16_LS64(\thread)
+	s.d	$f18, THREAD_FPR18_LS64(\thread)
+	s.d	$f20, THREAD_FPR20_LS64(\thread)
+	s.d	$f22, THREAD_FPR22_LS64(\thread)
+	s.d	$f24, THREAD_FPR24_LS64(\thread)
+	s.d	$f26, THREAD_FPR26_LS64(\thread)
+	s.d	$f28, THREAD_FPR28_LS64(\thread)
+	s.d	$f30, THREAD_FPR30_LS64(\thread)
 	sw	\tmp, THREAD_FCR31(\thread)
 	.set pop
 	.endm
@@ -56,38 +40,22 @@
 	.set push
 	SET_HARDFLOAT
 	lw	\tmp, THREAD_FCR31(\thread)
-	lwc1	$f0,  THREAD_FPR0_LS64(\thread)
-	lwc1	$f1,  THREAD_FPR1_LS64(\thread)
-	lwc1	$f2,  THREAD_FPR2_LS64(\thread)
-	lwc1	$f3,  THREAD_FPR3_LS64(\thread)
-	lwc1	$f4,  THREAD_FPR4_LS64(\thread)
-	lwc1	$f5,  THREAD_FPR5_LS64(\thread)
-	lwc1	$f6,  THREAD_FPR6_LS64(\thread)
-	lwc1	$f7,  THREAD_FPR7_LS64(\thread)
-	lwc1	$f8,  THREAD_FPR8_LS64(\thread)
-	lwc1	$f9,  THREAD_FPR9_LS64(\thread)
-	lwc1	$f10, THREAD_FPR10_LS64(\thread)
-	lwc1	$f11, THREAD_FPR11_LS64(\thread)
-	lwc1	$f12, THREAD_FPR12_LS64(\thread)
-	lwc1	$f13, THREAD_FPR13_LS64(\thread)
-	lwc1	$f14, THREAD_FPR14_LS64(\thread)
-	lwc1	$f15, THREAD_FPR15_LS64(\thread)
-	lwc1	$f16, THREAD_FPR16_LS64(\thread)
-	lwc1	$f17, THREAD_FPR17_LS64(\thread)
-	lwc1	$f18, THREAD_FPR18_LS64(\thread)
-	lwc1	$f19, THREAD_FPR19_LS64(\thread)
-	lwc1	$f20, THREAD_FPR20_LS64(\thread)
-	lwc1	$f21, THREAD_FPR21_LS64(\thread)
-	lwc1	$f22, THREAD_FPR22_LS64(\thread)
-	lwc1	$f23, THREAD_FPR23_LS64(\thread)
-	lwc1	$f24, THREAD_FPR24_LS64(\thread)
-	lwc1	$f25, THREAD_FPR25_LS64(\thread)
-	lwc1	$f26, THREAD_FPR26_LS64(\thread)
-	lwc1	$f27, THREAD_FPR27_LS64(\thread)
-	lwc1	$f28, THREAD_FPR28_LS64(\thread)
-	lwc1	$f29, THREAD_FPR29_LS64(\thread)
-	lwc1	$f30, THREAD_FPR30_LS64(\thread)
-	lwc1	$f31, THREAD_FPR31_LS64(\thread)
+	l.d	$f0,  THREAD_FPR0_LS64(\thread)
+	l.d	$f2,  THREAD_FPR2_LS64(\thread)
+	l.d	$f4,  THREAD_FPR4_LS64(\thread)
+	l.d	$f6,  THREAD_FPR6_LS64(\thread)
+	l.d	$f8,  THREAD_FPR8_LS64(\thread)
+	l.d	$f10, THREAD_FPR10_LS64(\thread)
+	l.d	$f12, THREAD_FPR12_LS64(\thread)
+	l.d	$f14, THREAD_FPR14_LS64(\thread)
+	l.d	$f16, THREAD_FPR16_LS64(\thread)
+	l.d	$f18, THREAD_FPR18_LS64(\thread)
+	l.d	$f20, THREAD_FPR20_LS64(\thread)
+	l.d	$f22, THREAD_FPR22_LS64(\thread)
+	l.d	$f24, THREAD_FPR24_LS64(\thread)
+	l.d	$f26, THREAD_FPR26_LS64(\thread)
+	l.d	$f28, THREAD_FPR28_LS64(\thread)
+	l.d	$f30, THREAD_FPR30_LS64(\thread)
 	ctc1	\tmp, fcr31
 	.set pop
 	.endm