MIPS: Fix build with binutils 2.24.51+
Starting with version 2.24.51.20140728 MIPS binutils complain loudly
about mixing soft-float and hard-float object files, leading to this
build failure since GCC is invoked with "-msoft-float" on MIPS:
{standard input}: Warning: .gnu_attribute 4,3 requires `softfloat'
LD arch/mips/alchemy/common/built-in.o
mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o
uses -msoft-float (set by arch/mips/alchemy/common/prom.o),
arch/mips/alchemy/common/sleeper.o uses -mhard-float
To fix this, we detect if GAS is new enough to support "-msoft-float" command
option, and if it does, we can let GCC pass it to GAS; but then we also need
to sprinkle the files which make use of floating point registers with the
necessary ".set hardfloat" directives.
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: Markos Chandras <Markos.Chandras@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/asmmacro-32.h b/arch/mips/include/asm/asmmacro-32.h
index e38c281..cdac7b3 100644
--- a/arch/mips/include/asm/asmmacro-32.h
+++ b/arch/mips/include/asm/asmmacro-32.h
@@ -13,6 +13,8 @@
#include <asm/mipsregs.h>
.macro fpu_save_single thread tmp=t0
+ .set push
+ SET_HARDFLOAT
cfc1 \tmp, fcr31
swc1 $f0, THREAD_FPR0_LS64(\thread)
swc1 $f1, THREAD_FPR1_LS64(\thread)
@@ -47,9 +49,12 @@
swc1 $f30, THREAD_FPR30_LS64(\thread)
swc1 $f31, THREAD_FPR31_LS64(\thread)
sw \tmp, THREAD_FCR31(\thread)
+ .set pop
.endm
.macro fpu_restore_single thread tmp=t0
+ .set push
+ SET_HARDFLOAT
lw \tmp, THREAD_FCR31(\thread)
lwc1 $f0, THREAD_FPR0_LS64(\thread)
lwc1 $f1, THREAD_FPR1_LS64(\thread)
@@ -84,6 +89,7 @@
lwc1 $f30, THREAD_FPR30_LS64(\thread)
lwc1 $f31, THREAD_FPR31_LS64(\thread)
ctc1 \tmp, fcr31
+ .set pop
.endm
.macro cpu_save_nonscratch thread
diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h
index cd9a98b..6caf876 100644
--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -57,6 +57,8 @@
#endif /* CONFIG_CPU_MIPSR2 */
.macro fpu_save_16even thread tmp=t0
+ .set push
+ SET_HARDFLOAT
cfc1 \tmp, fcr31
sdc1 $f0, THREAD_FPR0_LS64(\thread)
sdc1 $f2, THREAD_FPR2_LS64(\thread)
@@ -75,11 +77,13 @@
sdc1 $f28, THREAD_FPR28_LS64(\thread)
sdc1 $f30, THREAD_FPR30_LS64(\thread)
sw \tmp, THREAD_FCR31(\thread)
+ .set pop
.endm
.macro fpu_save_16odd thread
.set push
.set mips64r2
+ SET_HARDFLOAT
sdc1 $f1, THREAD_FPR1_LS64(\thread)
sdc1 $f3, THREAD_FPR3_LS64(\thread)
sdc1 $f5, THREAD_FPR5_LS64(\thread)
@@ -110,6 +114,8 @@
.endm
.macro fpu_restore_16even thread tmp=t0
+ .set push
+ SET_HARDFLOAT
lw \tmp, THREAD_FCR31(\thread)
ldc1 $f0, THREAD_FPR0_LS64(\thread)
ldc1 $f2, THREAD_FPR2_LS64(\thread)
@@ -133,6 +139,7 @@
.macro fpu_restore_16odd thread
.set push
.set mips64r2
+ SET_HARDFLOAT
ldc1 $f1, THREAD_FPR1_LS64(\thread)
ldc1 $f3, THREAD_FPR3_LS64(\thread)
ldc1 $f5, THREAD_FPR5_LS64(\thread)
@@ -277,6 +284,7 @@
.macro cfcmsa rd, cs
.set push
.set noat
+ SET_HARDFLOAT
.insn
.word CFC_MSA_INSN | (\cs << 11)
move \rd, $1
@@ -286,6 +294,7 @@
.macro ctcmsa cd, rs
.set push
.set noat
+ SET_HARDFLOAT
move $1, \rs
.word CTC_MSA_INSN | (\cd << 6)
.set pop
@@ -294,6 +303,7 @@
.macro ld_d wd, off, base
.set push
.set noat
+ SET_HARDFLOAT
add $1, \base, \off
.word LDD_MSA_INSN | (\wd << 6)
.set pop
@@ -302,6 +312,7 @@
.macro st_d wd, off, base
.set push
.set noat
+ SET_HARDFLOAT
add $1, \base, \off
.word STD_MSA_INSN | (\wd << 6)
.set pop
@@ -310,6 +321,7 @@
.macro copy_u_w rd, ws, n
.set push
.set noat
+ SET_HARDFLOAT
.insn
.word COPY_UW_MSA_INSN | (\n << 16) | (\ws << 11)
/* move triggers an assembler bug... */
@@ -320,6 +332,7 @@
.macro copy_u_d rd, ws, n
.set push
.set noat
+ SET_HARDFLOAT
.insn
.word COPY_UD_MSA_INSN | (\n << 16) | (\ws << 11)
/* move triggers an assembler bug... */
@@ -330,6 +343,7 @@
.macro insert_w wd, n, rs
.set push
.set noat
+ SET_HARDFLOAT
/* move triggers an assembler bug... */
or $1, \rs, zero
.word INSERT_W_MSA_INSN | (\n << 16) | (\wd << 6)
@@ -339,6 +353,7 @@
.macro insert_d wd, n, rs
.set push
.set noat
+ SET_HARDFLOAT
/* move triggers an assembler bug... */
or $1, \rs, zero
.word INSERT_D_MSA_INSN | (\n << 16) | (\wd << 6)
@@ -381,6 +396,7 @@
st_d 31, THREAD_FPR31, \thread
.set push
.set noat
+ SET_HARDFLOAT
cfcmsa $1, MSA_CSR
sw $1, THREAD_MSA_CSR(\thread)
.set pop
@@ -389,6 +405,7 @@
.macro msa_restore_all thread
.set push
.set noat
+ SET_HARDFLOAT
lw $1, THREAD_MSA_CSR(\thread)
ctcmsa MSA_CSR, $1
.set pop
@@ -441,6 +458,7 @@
.macro msa_init_all_upper
.set push
.set noat
+ SET_HARDFLOAT
not $1, zero
msa_init_upper 0
.set pop
diff --git a/arch/mips/include/asm/fpregdef.h b/arch/mips/include/asm/fpregdef.h
index 429481f..f184ba0 100644
--- a/arch/mips/include/asm/fpregdef.h
+++ b/arch/mips/include/asm/fpregdef.h
@@ -14,6 +14,20 @@
#include <asm/sgidefs.h>
+/*
+ * starting with binutils 2.24.51.20140729, MIPS binutils warn about mixing
+ * hardfloat and softfloat object files. The kernel build uses soft-float by
+ * default, so we also need to pass -msoft-float along to GAS if it supports it.
+ * But this in turn causes assembler errors in files which access hardfloat
+ * registers. We detect if GAS supports "-msoft-float" in the Makefile and
+ * explicitly put ".set hardfloat" where floating point registers are touched.
+ */
+#ifdef GAS_HAS_SET_HARDFLOAT
+#define SET_HARDFLOAT .set hardfloat
+#else
+#define SET_HARDFLOAT
+#endif
+
#if _MIPS_SIM == _MIPS_SIM_ABI32
/*
diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h
index 4d0aeda..dd56241 100644
--- a/arch/mips/include/asm/fpu.h
+++ b/arch/mips/include/asm/fpu.h
@@ -145,8 +145,8 @@
if (is_msa_enabled()) {
if (save) {
save_msa(current);
- asm volatile("cfc1 %0, $31"
- : "=r"(current->thread.fpu.fcr31));
+ current->thread.fpu.fcr31 =
+ read_32bit_cp1_register(CP1_STATUS);
}
disable_msa();
clear_thread_flag(TIF_USEDMSA);
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index cf3b580..b46cd22 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -1324,7 +1324,7 @@
/*
* Macros to access the floating point coprocessor control registers
*/
-#define read_32bit_cp1_register(source) \
+#define _read_32bit_cp1_register(source, gas_hardfloat) \
({ \
int __res; \
\
@@ -1334,12 +1334,21 @@
" # gas fails to assemble cfc1 for some archs, \n" \
" # like Octeon. \n" \
" .set mips1 \n" \
+ " "STR(gas_hardfloat)" \n" \
" cfc1 %0,"STR(source)" \n" \
" .set pop \n" \
: "=r" (__res)); \
__res; \
})
+#ifdef GAS_HAS_SET_HARDFLOAT
+#define read_32bit_cp1_register(source) \
+ _read_32bit_cp1_register(source, .set hardfloat)
+#else
+#define read_32bit_cp1_register(source) \
+ _read_32bit_cp1_register(source, )
+#endif
+
#ifdef HAVE_AS_DSP
#define rddsp(mask) \
({ \