[linux-yocto] [PATCH] MIPS: Fix build with binutils 2.24.51+
Yang Shi
yang.shi at windriver.com
Wed Jul 15 15:13:41 PDT 2015
From: Manuel Lauss <manuel.lauss at gmail.com>
commit 842dfc11ea9a21f9825167c8a4f2834b205b0a79 upstream
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 at gmail.com>
Cc: Linux-MIPS <linux-mips at linux-mips.org>
Cc: Matthew Fortune <Matthew.Fortune at imgtec.com>
Cc: Markos Chandras <Markos.Chandras at imgtec.com>
Cc: Maciej W. Rozycki <macro at linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8355/
Signed-off-by: Ralf Baechle <ralf at linux-mips.org>
[yshi: Backported to Yocto 3.14 kernel]
Signed-off-by: Yang Shi <yang.shi at windriver.com>
---
arch/mips/Makefile | 9 +++++++++
arch/mips/include/asm/asmmacro-32.h | 6 ++++++
arch/mips/include/asm/asmmacro.h | 7 +++++++
arch/mips/include/asm/fpregdef.h | 14 ++++++++++++++
arch/mips/include/asm/mipsregs.h | 11 ++++++++++-
arch/mips/kernel/branch.c | 6 +-----
arch/mips/kernel/genex.S | 1 +
arch/mips/kernel/r2300_fpu.S | 6 ++++++
arch/mips/kernel/r2300_switch.S | 5 +++++
arch/mips/kernel/r4k_fpu.S | 27 +++++++++++++++++++++++++--
arch/mips/kernel/r4k_switch.S | 11 ++++++++++-
arch/mips/kernel/r6000_fpu.S | 5 +++++
arch/mips/math-emu/cp1emu.c | 6 +-----
13 files changed, 100 insertions(+), 14 deletions(-)
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 69bd6f7..c1a7f83 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -96,6 +96,15 @@ KBUILD_AFLAGS_MODULE += -mlong-calls
KBUILD_CFLAGS_MODULE += -mlong-calls
endif
+#
+# pass -msoft-float to GAS if it supports it. However on newer binutils
+# (specifically newer than 2.24.51.20140728) we then also need to explicitly
+# set ".set hardfloat" in all files which manipulate floating point registers.
+#
+ifneq ($(call as-option,-Wa$(comma)-msoft-float,),)
+ cflags-y += -DGAS_HAS_SET_HARDFLOAT -Wa,-msoft-float
+endif
+
cflags-y += -ffreestanding
#
diff --git a/arch/mips/include/asm/asmmacro-32.h b/arch/mips/include/asm/asmmacro-32.h
index 70e1f17..8038647 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(\thread)
swc1 $f1, THREAD_FPR1(\thread)
@@ -47,9 +49,12 @@
swc1 $f30, THREAD_FPR30(\thread)
swc1 $f31, THREAD_FPR31(\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(\thread)
lwc1 $f1, THREAD_FPR1(\thread)
@@ -84,6 +89,7 @@
lwc1 $f30, THREAD_FPR30(\thread)
lwc1 $f31, THREAD_FPR31(\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 4225e99..d6d5b19 100644
--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -74,6 +74,8 @@
#endif /* CONFIG_MIPS_MT_SMTC */
.macro fpu_save_16even thread tmp=t0
+ .set push
+ SET_HARDFLOAT
cfc1 \tmp, fcr31
sdc1 $f0, THREAD_FPR0(\thread)
sdc1 $f2, THREAD_FPR2(\thread)
@@ -92,11 +94,13 @@
sdc1 $f28, THREAD_FPR28(\thread)
sdc1 $f30, THREAD_FPR30(\thread)
sw \tmp, THREAD_FCR31(\thread)
+ .set pop
.endm
.macro fpu_save_16odd thread
.set push
.set mips64r2
+ SET_HARDFLOAT
sdc1 $f1, THREAD_FPR1(\thread)
sdc1 $f3, THREAD_FPR3(\thread)
sdc1 $f5, THREAD_FPR5(\thread)
@@ -127,6 +131,8 @@
.endm
.macro fpu_restore_16even thread tmp=t0
+ .set push
+ SET_HARDFLOAT
lw \tmp, THREAD_FCR31(\thread)
ldc1 $f0, THREAD_FPR0(\thread)
ldc1 $f2, THREAD_FPR2(\thread)
@@ -150,6 +156,7 @@
.macro fpu_restore_16odd thread
.set push
.set mips64r2
+ SET_HARDFLOAT
ldc1 $f1, THREAD_FPR1(\thread)
ldc1 $f3, THREAD_FPR3(\thread)
ldc1 $f5, THREAD_FPR5(\thread)
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/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index d6a8ced..67a209f 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -1518,7 +1518,7 @@ do { \
/*
* 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; \
\
@@ -1528,12 +1528,21 @@ do { \
" # 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) \
({ \
diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index ecba7eb..d14383d 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c
@@ -438,11 +438,7 @@ static unsigned int __get_fcr31(void)
preempt_disable();
if (is_fpu_owner())
- asm volatile(
- ".set push\n"
- "\t.set mips1\n"
- "\tcfc1\t%0,$31\n"
- "\t.set pop" : "=r" (fcr31));
+ fcr31 = read_32bit_cp1_register(CP1_STATUS);
else
fcr31 = current->thread.fpu.fcr31;
preempt_enable();
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index eb59fed..7b7611a 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -432,6 +432,7 @@ NESTED(nmi_handler, PT_SIZE, sp)
.set push
/* gas fails to assemble cfc1 for some archs (octeon).*/ \
.set mips1
+ SET_HARDFLOAT
cfc1 a1, fcr31
li a2, ~(0x3f << 12)
and a2, a1
diff --git a/arch/mips/kernel/r2300_fpu.S b/arch/mips/kernel/r2300_fpu.S
index f31063d..5ce3b74 100644
--- a/arch/mips/kernel/r2300_fpu.S
+++ b/arch/mips/kernel/r2300_fpu.S
@@ -28,6 +28,8 @@
.set mips1
/* Save floating point context */
LEAF(_save_fp_context)
+ .set push
+ SET_HARDFLOAT
li v0, 0 # assume success
cfc1 t1,fcr31
EX(swc1 $f0,(SC_FPREGS+0)(a0))
@@ -65,6 +67,7 @@ LEAF(_save_fp_context)
EX(sw t1,(SC_FPC_CSR)(a0))
cfc1 t0,$0 # implementation/version
jr ra
+ .set pop
.set nomacro
EX(sw t0,(SC_FPC_EIR)(a0))
.set macro
@@ -80,6 +83,8 @@ LEAF(_save_fp_context)
* stack frame which might have been changed by the user.
*/
LEAF(_restore_fp_context)
+ .set push
+ SET_HARDFLOAT
li v0, 0 # assume success
EX(lw t0,(SC_FPC_CSR)(a0))
EX(lwc1 $f0,(SC_FPREGS+0)(a0))
@@ -116,6 +121,7 @@ LEAF(_restore_fp_context)
EX(lwc1 $f31,(SC_FPREGS+248)(a0))
jr ra
ctc1 t0,fcr31
+ .set pop
END(_restore_fp_context)
.set reorder
diff --git a/arch/mips/kernel/r2300_switch.S b/arch/mips/kernel/r2300_switch.S
index 20b7b04..435ea65 100644
--- a/arch/mips/kernel/r2300_switch.S
+++ b/arch/mips/kernel/r2300_switch.S
@@ -120,6 +120,9 @@ LEAF(_restore_fp)
#define FPU_DEFAULT 0x00000000
+ .set push
+ SET_HARDFLOAT
+
LEAF(_init_fpu)
mfc0 t0, CP0_STATUS
li t1, ST0_CU1
@@ -165,3 +168,5 @@ LEAF(_init_fpu)
mtc1 t0, $f31
jr ra
END(_init_fpu)
+
+ .set pop
diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S
index 73b0ddf..06f8b2a 100644
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -19,8 +19,12 @@
#include <asm/asm-offsets.h>
#include <asm/regdef.h>
+/* preprocessor replaces the fp in ".set fp=64" with $30 otherwise */
+#undef fp
+
.macro EX insn, reg, src
.set push
+ SET_HARDFLOAT
.set nomacro
.ex\@: \insn \reg, \src
.set pop
@@ -33,12 +37,17 @@
.set mips3
LEAF(_save_fp_context)
+ .set push
+ SET_HARDFLOAT
cfc1 t1, fcr31
+ .set pop
#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
.set push
+ SET_HARDFLOAT
#ifdef CONFIG_CPU_MIPS32_R2
- .set mips64r2
+ .set mips32r2
+ .set fp=64
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip storing odd if FR=0
@@ -64,6 +73,8 @@ LEAF(_save_fp_context)
1: .set pop
#endif
+ .set push
+ SET_HARDFLOAT
/* Store the 16 even double precision registers */
EX sdc1 $f0, SC_FPREGS+0(a0)
EX sdc1 $f2, SC_FPREGS+16(a0)
@@ -84,11 +95,14 @@ LEAF(_save_fp_context)
EX sw t1, SC_FPC_CSR(a0)
jr ra
li v0, 0 # success
+ .set pop
END(_save_fp_context)
#ifdef CONFIG_MIPS32_COMPAT
/* Save 32-bit process floating point context */
LEAF(_save_fp_context32)
+ .set push
+ SET_HARDFLOAT
cfc1 t1, fcr31
mfc0 t0, CP0_STATUS
@@ -134,6 +148,7 @@ LEAF(_save_fp_context32)
EX sw t1, SC32_FPC_CSR(a0)
cfc1 t0, $0 # implementation/version
EX sw t0, SC32_FPC_EIR(a0)
+ .set pop
jr ra
li v0, 0 # success
@@ -150,8 +165,10 @@ LEAF(_restore_fp_context)
#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
.set push
+ SET_HARDFLOAT
#ifdef CONFIG_CPU_MIPS32_R2
- .set mips64r2
+ .set mips32r2
+ .set fp=64
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip loading odd if FR=0
@@ -175,6 +192,8 @@ LEAF(_restore_fp_context)
EX ldc1 $f31, SC_FPREGS+248(a0)
1: .set pop
#endif
+ .set push
+ SET_HARDFLOAT
EX ldc1 $f0, SC_FPREGS+0(a0)
EX ldc1 $f2, SC_FPREGS+16(a0)
EX ldc1 $f4, SC_FPREGS+32(a0)
@@ -192,6 +211,7 @@ LEAF(_restore_fp_context)
EX ldc1 $f28, SC_FPREGS+224(a0)
EX ldc1 $f30, SC_FPREGS+240(a0)
ctc1 t1, fcr31
+ .set pop
jr ra
li v0, 0 # success
END(_restore_fp_context)
@@ -199,6 +219,8 @@ LEAF(_restore_fp_context)
#ifdef CONFIG_MIPS32_COMPAT
LEAF(_restore_fp_context32)
/* Restore an o32 sigcontext. */
+ .set push
+ SET_HARDFLOAT
EX lw t1, SC32_FPC_CSR(a0)
mfc0 t0, CP0_STATUS
@@ -242,6 +264,7 @@ LEAF(_restore_fp_context32)
ctc1 t1, fcr31
jr ra
li v0, 0 # success
+ .set pop
END(_restore_fp_context32)
#endif
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index 8a4f9a5..715fb13 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -22,6 +22,9 @@
#include <asm/asmmacro.h>
+/* preprocessor replaces the fp in ".set fp=64" with $30 otherwise */
+#undef fp
+
/*
* Offset to the current process status flags, the first 32 bytes of the
* stack are not used.
@@ -154,6 +157,9 @@ LEAF(_restore_fp)
#define FPU_DEFAULT 0x00000000
+ .set push
+ SET_HARDFLOAT
+
LEAF(_init_fpu)
#ifdef CONFIG_MIPS_MT_SMTC
/* Rather than manipulate per-VPE Status, set per-TC bit in TCStatus */
@@ -234,7 +240,8 @@ LEAF(_init_fpu)
#ifdef CONFIG_CPU_MIPS32_R2
.set push
- .set mips64r2
+ .set mips32r2
+ .set fp=64
sll t0, t0, 5 # is Status.FR set?
bgez t0, 1f # no: skip setting upper 32b
@@ -293,3 +300,5 @@ LEAF(_init_fpu)
#endif
jr ra
END(_init_fpu)
+
+ .set pop /* SET_HARDFLOAT */
diff --git a/arch/mips/kernel/r6000_fpu.S b/arch/mips/kernel/r6000_fpu.S
index da0fbe4..4707738 100644
--- a/arch/mips/kernel/r6000_fpu.S
+++ b/arch/mips/kernel/r6000_fpu.S
@@ -18,6 +18,9 @@
.set noreorder
.set mips2
+ .set push
+ SET_HARDFLOAT
+
/* Save floating point context */
LEAF(_save_fp_context)
mfc0 t0,CP0_STATUS
@@ -85,3 +88,5 @@
1: jr ra
nop
END(_restore_fp_context)
+
+ .set pop /* SET_HARDFLOAT */
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index edb110c..4e9e3c1 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -821,11 +821,7 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
if (insn.i_format.rs == bc_op) {
preempt_disable();
if (is_fpu_owner())
- asm volatile(
- ".set push\n"
- "\t.set mips1\n"
- "\tcfc1\t%0,$31\n"
- "\t.set pop" : "=r" (fcr31));
+ fcr31 = read_32bit_cp1_register(CP1_STATUS);
else
fcr31 = current->thread.fpu.fcr31;
preempt_enable();
--
2.0.2
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