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MIPS: Support for 64-bit FP with O32 binaries

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CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs
do. In order to preserve backwards compatibility a 64-bit FPU will act
like a 32-bit FPU (by accessing doubles from the least significant 32
bits of an even-odd pair of FP registers) when the Status.FR bit is
zero, again just like a mips64 CPU. The standard O32 ABI is defined
expecting a 32-bit FPU, however recent toolchains support use of a
64-bit FPU from an O32 MIPS32 executable. When an ELF executable is
built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF
header.

With this patch the kernel will check the EF_MIPS_FP64 flag when
executing an O32 binary, and set Status.FR accordingly. The addition
of O32 64-bit FP support lessens the opportunity for optimisation in
the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is
introduced to allow this support to be disabled for those that don't
require it.

Inspired by an earlier patch by Leonid Yegoshin, but implemented more
cleanly & correctly.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/6154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Paul Burton 2013-11-22 13:12:07 +00:00 • committed by Ralf Baechle
commit 597ce1723e
19 changed files with 449 additions and 236 deletions
Download patch file Download diff file Expand all files Collapse all files

17
arch/mips/Kconfig
View file

@ -2335,6 +2335,23 @@ config CC_STACKPROTECTOR
This feature requires gcc version 4.2 or above.
config MIPS_O32_FP64_SUPPORT
bool "Support for O32 binaries using 64-bit FP"
depends on 32BIT || MIPS32_O32
default y
help
When this is enabled, the kernel will support use of 64-bit floating
point registers with binaries using the O32 ABI along with the
EF_MIPS_FP64 ELF header flag (typically built with -mfp64). On
32-bit MIPS systems this support is at the cost of increasing the
size and complexity of the compiled FPU emulator. Thus if you are
running a MIPS32 system and know that none of your userland binaries
will require 64-bit floating point, you may wish to reduce the size
of your kernel & potentially improve FP emulation performance by
saying N here.
If unsure, say Y.
config USE_OF
bool
select OF

42
arch/mips/include/asm/asmmacro-32.h
View file

@ -12,27 +12,6 @@
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
.macro fpu_save_double thread status tmp1=t0
cfc1 \tmp1, fcr31
sdc1 $f0, THREAD_FPR0(\thread)
sdc1 $f2, THREAD_FPR2(\thread)
sdc1 $f4, THREAD_FPR4(\thread)
sdc1 $f6, THREAD_FPR6(\thread)
sdc1 $f8, THREAD_FPR8(\thread)
sdc1 $f10, THREAD_FPR10(\thread)
sdc1 $f12, THREAD_FPR12(\thread)
sdc1 $f14, THREAD_FPR14(\thread)
sdc1 $f16, THREAD_FPR16(\thread)
sdc1 $f18, THREAD_FPR18(\thread)
sdc1 $f20, THREAD_FPR20(\thread)
sdc1 $f22, THREAD_FPR22(\thread)
sdc1 $f24, THREAD_FPR24(\thread)
sdc1 $f26, THREAD_FPR26(\thread)
sdc1 $f28, THREAD_FPR28(\thread)
sdc1 $f30, THREAD_FPR30(\thread)
sw \tmp1, THREAD_FCR31(\thread)
.endm
.macro fpu_save_single thread tmp=t0
cfc1 \tmp, fcr31
swc1 $f0, THREAD_FPR0(\thread)
@ -70,27 +49,6 @@
sw \tmp, THREAD_FCR31(\thread)
.endm
.macro fpu_restore_double thread status tmp=t0
lw \tmp, THREAD_FCR31(\thread)
ldc1 $f0, THREAD_FPR0(\thread)
ldc1 $f2, THREAD_FPR2(\thread)
ldc1 $f4, THREAD_FPR4(\thread)
ldc1 $f6, THREAD_FPR6(\thread)
ldc1 $f8, THREAD_FPR8(\thread)
ldc1 $f10, THREAD_FPR10(\thread)
ldc1 $f12, THREAD_FPR12(\thread)
ldc1 $f14, THREAD_FPR14(\thread)
ldc1 $f16, THREAD_FPR16(\thread)
ldc1 $f18, THREAD_FPR18(\thread)
ldc1 $f20, THREAD_FPR20(\thread)
ldc1 $f22, THREAD_FPR22(\thread)
ldc1 $f24, THREAD_FPR24(\thread)
ldc1 $f26, THREAD_FPR26(\thread)
ldc1 $f28, THREAD_FPR28(\thread)
ldc1 $f30, THREAD_FPR30(\thread)
ctc1 \tmp, fcr31
.endm
.macro fpu_restore_single thread tmp=t0
lw \tmp, THREAD_FCR31(\thread)
lwc1 $f0, THREAD_FPR0(\thread)

96
arch/mips/include/asm/asmmacro-64.h
View file

@ -13,102 +13,6 @@
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
.macro fpu_save_16even thread tmp=t0
cfc1 \tmp, fcr31
sdc1 $f0, THREAD_FPR0(\thread)
sdc1 $f2, THREAD_FPR2(\thread)
sdc1 $f4, THREAD_FPR4(\thread)
sdc1 $f6, THREAD_FPR6(\thread)
sdc1 $f8, THREAD_FPR8(\thread)
sdc1 $f10, THREAD_FPR10(\thread)
sdc1 $f12, THREAD_FPR12(\thread)
sdc1 $f14, THREAD_FPR14(\thread)
sdc1 $f16, THREAD_FPR16(\thread)
sdc1 $f18, THREAD_FPR18(\thread)
sdc1 $f20, THREAD_FPR20(\thread)
sdc1 $f22, THREAD_FPR22(\thread)
sdc1 $f24, THREAD_FPR24(\thread)
sdc1 $f26, THREAD_FPR26(\thread)
sdc1 $f28, THREAD_FPR28(\thread)
sdc1 $f30, THREAD_FPR30(\thread)
sw \tmp, THREAD_FCR31(\thread)
.endm
.macro fpu_save_16odd thread
sdc1 $f1, THREAD_FPR1(\thread)
sdc1 $f3, THREAD_FPR3(\thread)
sdc1 $f5, THREAD_FPR5(\thread)
sdc1 $f7, THREAD_FPR7(\thread)
sdc1 $f9, THREAD_FPR9(\thread)
sdc1 $f11, THREAD_FPR11(\thread)
sdc1 $f13, THREAD_FPR13(\thread)
sdc1 $f15, THREAD_FPR15(\thread)
sdc1 $f17, THREAD_FPR17(\thread)
sdc1 $f19, THREAD_FPR19(\thread)
sdc1 $f21, THREAD_FPR21(\thread)
sdc1 $f23, THREAD_FPR23(\thread)
sdc1 $f25, THREAD_FPR25(\thread)
sdc1 $f27, THREAD_FPR27(\thread)
sdc1 $f29, THREAD_FPR29(\thread)
sdc1 $f31, THREAD_FPR31(\thread)
.endm
.macro fpu_save_double thread status tmp
sll \tmp, \status, 5
bgez \tmp, 2f
fpu_save_16odd \thread
2:
fpu_save_16even \thread \tmp
.endm
.macro fpu_restore_16even thread tmp=t0
lw \tmp, THREAD_FCR31(\thread)
ldc1 $f0, THREAD_FPR0(\thread)
ldc1 $f2, THREAD_FPR2(\thread)
ldc1 $f4, THREAD_FPR4(\thread)
ldc1 $f6, THREAD_FPR6(\thread)
ldc1 $f8, THREAD_FPR8(\thread)
ldc1 $f10, THREAD_FPR10(\thread)
ldc1 $f12, THREAD_FPR12(\thread)
ldc1 $f14, THREAD_FPR14(\thread)
ldc1 $f16, THREAD_FPR16(\thread)
ldc1 $f18, THREAD_FPR18(\thread)
ldc1 $f20, THREAD_FPR20(\thread)
ldc1 $f22, THREAD_FPR22(\thread)
ldc1 $f24, THREAD_FPR24(\thread)
ldc1 $f26, THREAD_FPR26(\thread)
ldc1 $f28, THREAD_FPR28(\thread)
ldc1 $f30, THREAD_FPR30(\thread)
ctc1 \tmp, fcr31
.endm
.macro fpu_restore_16odd thread
ldc1 $f1, THREAD_FPR1(\thread)
ldc1 $f3, THREAD_FPR3(\thread)
ldc1 $f5, THREAD_FPR5(\thread)
ldc1 $f7, THREAD_FPR7(\thread)
ldc1 $f9, THREAD_FPR9(\thread)
ldc1 $f11, THREAD_FPR11(\thread)
ldc1 $f13, THREAD_FPR13(\thread)
ldc1 $f15, THREAD_FPR15(\thread)
ldc1 $f17, THREAD_FPR17(\thread)
ldc1 $f19, THREAD_FPR19(\thread)
ldc1 $f21, THREAD_FPR21(\thread)
ldc1 $f23, THREAD_FPR23(\thread)
ldc1 $f25, THREAD_FPR25(\thread)
ldc1 $f27, THREAD_FPR27(\thread)
ldc1 $f29, THREAD_FPR29(\thread)
ldc1 $f31, THREAD_FPR31(\thread)
.endm
.macro fpu_restore_double thread status tmp
sll \tmp, \status, 5
bgez \tmp, 1f # 16 register mode?
fpu_restore_16odd \thread
1: fpu_restore_16even \thread \tmp
.endm
.macro cpu_save_nonscratch thread
LONG_S s0, THREAD_REG16(\thread)
LONG_S s1, THREAD_REG17(\thread)

107
arch/mips/include/asm/asmmacro.h
View file

@ -62,6 +62,113 @@
.endm
#endif /* CONFIG_MIPS_MT_SMTC */
.macro fpu_save_16even thread tmp=t0
cfc1 \tmp, fcr31
sdc1 $f0, THREAD_FPR0(\thread)
sdc1 $f2, THREAD_FPR2(\thread)
sdc1 $f4, THREAD_FPR4(\thread)
sdc1 $f6, THREAD_FPR6(\thread)
sdc1 $f8, THREAD_FPR8(\thread)
sdc1 $f10, THREAD_FPR10(\thread)
sdc1 $f12, THREAD_FPR12(\thread)
sdc1 $f14, THREAD_FPR14(\thread)
sdc1 $f16, THREAD_FPR16(\thread)
sdc1 $f18, THREAD_FPR18(\thread)
sdc1 $f20, THREAD_FPR20(\thread)
sdc1 $f22, THREAD_FPR22(\thread)
sdc1 $f24, THREAD_FPR24(\thread)
sdc1 $f26, THREAD_FPR26(\thread)
sdc1 $f28, THREAD_FPR28(\thread)
sdc1 $f30, THREAD_FPR30(\thread)
sw \tmp, THREAD_FCR31(\thread)
.endm
.macro fpu_save_16odd thread
.set push
.set mips64r2
sdc1 $f1, THREAD_FPR1(\thread)
sdc1 $f3, THREAD_FPR3(\thread)
sdc1 $f5, THREAD_FPR5(\thread)
sdc1 $f7, THREAD_FPR7(\thread)
sdc1 $f9, THREAD_FPR9(\thread)
sdc1 $f11, THREAD_FPR11(\thread)
sdc1 $f13, THREAD_FPR13(\thread)
sdc1 $f15, THREAD_FPR15(\thread)
sdc1 $f17, THREAD_FPR17(\thread)
sdc1 $f19, THREAD_FPR19(\thread)
sdc1 $f21, THREAD_FPR21(\thread)
sdc1 $f23, THREAD_FPR23(\thread)
sdc1 $f25, THREAD_FPR25(\thread)
sdc1 $f27, THREAD_FPR27(\thread)
sdc1 $f29, THREAD_FPR29(\thread)
sdc1 $f31, THREAD_FPR31(\thread)
.set pop
.endm
.macro fpu_save_double thread status tmp
#if defined(CONFIG_MIPS64) || defined(CONFIG_CPU_MIPS32_R2)
sll \tmp, \status, 5
bgez \tmp, 10f
fpu_save_16odd \thread
10:
#endif
fpu_save_16even \thread \tmp
.endm
.macro fpu_restore_16even thread tmp=t0
lw \tmp, THREAD_FCR31(\thread)
ldc1 $f0, THREAD_FPR0(\thread)
ldc1 $f2, THREAD_FPR2(\thread)
ldc1 $f4, THREAD_FPR4(\thread)
ldc1 $f6, THREAD_FPR6(\thread)
ldc1 $f8, THREAD_FPR8(\thread)
ldc1 $f10, THREAD_FPR10(\thread)
ldc1 $f12, THREAD_FPR12(\thread)
ldc1 $f14, THREAD_FPR14(\thread)
ldc1 $f16, THREAD_FPR16(\thread)
ldc1 $f18, THREAD_FPR18(\thread)
ldc1 $f20, THREAD_FPR20(\thread)
ldc1 $f22, THREAD_FPR22(\thread)
ldc1 $f24, THREAD_FPR24(\thread)
ldc1 $f26, THREAD_FPR26(\thread)
ldc1 $f28, THREAD_FPR28(\thread)
ldc1 $f30, THREAD_FPR30(\thread)
ctc1 \tmp, fcr31
.endm
.macro fpu_restore_16odd thread
.set push
.set mips64r2
ldc1 $f1, THREAD_FPR1(\thread)
ldc1 $f3, THREAD_FPR3(\thread)
ldc1 $f5, THREAD_FPR5(\thread)
ldc1 $f7, THREAD_FPR7(\thread)
ldc1 $f9, THREAD_FPR9(\thread)
ldc1 $f11, THREAD_FPR11(\thread)
ldc1 $f13, THREAD_FPR13(\thread)
ldc1 $f15, THREAD_FPR15(\thread)
ldc1 $f17, THREAD_FPR17(\thread)
ldc1 $f19, THREAD_FPR19(\thread)
ldc1 $f21, THREAD_FPR21(\thread)
ldc1 $f23, THREAD_FPR23(\thread)
ldc1 $f25, THREAD_FPR25(\thread)
ldc1 $f27, THREAD_FPR27(\thread)
ldc1 $f29, THREAD_FPR29(\thread)
ldc1 $f31, THREAD_FPR31(\thread)
.set pop
.endm
.macro fpu_restore_double thread status tmp
#if defined(CONFIG_MIPS64) || defined(CONFIG_CPU_MIPS32_R2)
sll \tmp, \status, 5
bgez \tmp, 10f # 16 register mode?
fpu_restore_16odd \thread
10:
#endif
fpu_restore_16even \thread \tmp
.endm
/*
* Temporary until all gas have MT ASE support
*/

31
arch/mips/include/asm/elf.h
View file

@ -36,6 +36,7 @@
#define EF_MIPS_ABI2 0x00000020
#define EF_MIPS_OPTIONS_FIRST 0x00000080
#define EF_MIPS_32BITMODE 0x00000100
#define EF_MIPS_FP64 0x00000200
#define EF_MIPS_ABI 0x0000f000
#define EF_MIPS_ARCH 0xf0000000
@ -175,6 +176,18 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
#ifdef CONFIG_32BIT
/*
* In order to be sure that we don't attempt to execute an O32 binary which
* requires 64 bit FP (FR=1) on a system which does not support it we refuse
* to execute any binary which has bits specified by the following macro set
* in its ELF header flags.
*/
#ifdef CONFIG_MIPS_O32_FP64_SUPPORT
# define __MIPS_O32_FP64_MUST_BE_ZERO 0
#else
# define __MIPS_O32_FP64_MUST_BE_ZERO EF_MIPS_FP64
#endif
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
@ -191,6 +204,8 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
__res = 0; \
if (((__h->e_flags & EF_MIPS_ABI) != 0) && \
((__h->e_flags & EF_MIPS_ABI) != EF_MIPS_ABI_O32)) \
__res = 0; \
if (__h->e_flags & __MIPS_O32_FP64_MUST_BE_ZERO) \
__res = 0; \
\
__res; \
@ -249,6 +264,11 @@ extern struct mips_abi mips_abi_n32;
#define SET_PERSONALITY(ex) \
do { \
if ((ex).e_flags & EF_MIPS_FP64) \
clear_thread_flag(TIF_32BIT_FPREGS); \
else \
set_thread_flag(TIF_32BIT_FPREGS); \
\
if (personality(current->personality) != PER_LINUX) \
set_personality(PER_LINUX); \
\
@ -271,14 +291,18 @@ do { \
#endif
#ifdef CONFIG_MIPS32_O32
#define __SET_PERSONALITY32_O32() \
#define __SET_PERSONALITY32_O32(ex) \
do { \
set_thread_flag(TIF_32BIT_REGS); \
set_thread_flag(TIF_32BIT_ADDR); \
\
if (!((ex).e_flags & EF_MIPS_FP64)) \
set_thread_flag(TIF_32BIT_FPREGS); \
\
current->thread.abi = &mips_abi_32; \
} while (0)
#else
#define __SET_PERSONALITY32_O32() \
#define __SET_PERSONALITY32_O32(ex) \
do { } while (0)
#endif
@ -289,7 +313,7 @@ do { \
((ex).e_flags & EF_MIPS_ABI) == 0) \
__SET_PERSONALITY32_N32(); \
else \
__SET_PERSONALITY32_O32(); \
__SET_PERSONALITY32_O32(ex); \
} while (0)
#else
#define __SET_PERSONALITY32(ex) do { } while (0)
@ -300,6 +324,7 @@ do { \
unsigned int p; \
\
clear_thread_flag(TIF_32BIT_REGS); \
clear_thread_flag(TIF_32BIT_FPREGS); \
clear_thread_flag(TIF_32BIT_ADDR); \
\
if ((ex).e_ident[EI_CLASS] == ELFCLASS32) \

91
arch/mips/include/asm/fpu.h
View file

@ -33,11 +33,48 @@ extern void _init_fpu(void);
extern void _save_fp(struct task_struct *);
extern void _restore_fp(struct task_struct *);
#define __enable_fpu() \
do { \
set_c0_status(ST0_CU1); \
enable_fpu_hazard(); \
} while (0)
/*
* This enum specifies a mode in which we want the FPU to operate, for cores
* which implement the Status.FR bit. Note that FPU_32BIT & FPU_64BIT
* purposefully have the values 0 & 1 respectively, so that an integer value
* of Status.FR can be trivially casted to the corresponding enum fpu_mode.
*/
enum fpu_mode {
FPU_32BIT = 0, /* FR = 0 */
FPU_64BIT, /* FR = 1 */
FPU_AS_IS,
};
static inline int __enable_fpu(enum fpu_mode mode)
{
int fr;
switch (mode) {
case FPU_AS_IS:
/* just enable the FPU in its current mode */
set_c0_status(ST0_CU1);
enable_fpu_hazard();
return 0;
case FPU_64BIT:
#if !(defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_MIPS64))
/* we only have a 32-bit FPU */
return SIGFPE;
#endif
/* fall through */
case FPU_32BIT:
/* set CU1 & change FR appropriately */
fr = (int)mode;
change_c0_status(ST0_CU1 | ST0_FR, ST0_CU1 | (fr ? ST0_FR : 0));
enable_fpu_hazard();
/* check FR has the desired value */
return (!!(read_c0_status() & ST0_FR) == !!fr) ? 0 : SIGFPE;
default:
BUG();
}
}
#define __disable_fpu() \
do { \
@ -57,27 +94,46 @@ static inline int is_fpu_owner(void)
return cpu_has_fpu && __is_fpu_owner();
}
static inline void __own_fpu(void)
static inline int __own_fpu(void)
{
__enable_fpu();
enum fpu_mode mode;
int ret;
mode = !test_thread_flag(TIF_32BIT_FPREGS);
ret = __enable_fpu(mode);
if (ret)
return ret;
KSTK_STATUS(current) |= ST0_CU1;
if (mode == FPU_64BIT)
KSTK_STATUS(current) |= ST0_FR;
else /* mode == FPU_32BIT */
KSTK_STATUS(current) &= ~ST0_FR;
set_thread_flag(TIF_USEDFPU);
return 0;
}
static inline void own_fpu_inatomic(int restore)
static inline int own_fpu_inatomic(int restore)
{
int ret = 0;
if (cpu_has_fpu && !__is_fpu_owner()) {
__own_fpu();
if (restore)
ret = __own_fpu();
if (restore && !ret)
_restore_fp(current);
}
return ret;
}
static inline void own_fpu(int restore)
static inline int own_fpu(int restore)
{
int ret;
preempt_disable();
own_fpu_inatomic(restore);
ret = own_fpu_inatomic(restore);
preempt_enable();
return ret;
}
static inline void lose_fpu(int save)
@ -93,16 +149,21 @@ static inline void lose_fpu(int save)
preempt_enable();
}
static inline void init_fpu(void)
static inline int init_fpu(void)
{
int ret = 0;
preempt_disable();
if (cpu_has_fpu) {
__own_fpu();
_init_fpu();
ret = __own_fpu();
if (!ret)
_init_fpu();
} else {
fpu_emulator_init_fpu();
}
preempt_enable();
return ret;
}
static inline void save_fp(struct task_struct *tsk)

4
arch/mips/include/asm/thread_info.h
View file

@ -110,11 +110,12 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NOHZ 19 /* in adaptive nohz mode */
#define TIF_FIXADE 20 /* Fix address errors in software */
#define TIF_LOGADE 21 /* Log address errors to syslog */
#define TIF_32BIT_REGS 22 /* also implies 16/32 fprs */
#define TIF_32BIT_REGS 22 /* 32-bit general purpose registers */
#define TIF_32BIT_ADDR 23 /* 32-bit address space (o32/n32) */
#define TIF_FPUBOUND 24 /* thread bound to FPU-full CPU set */
#define TIF_LOAD_WATCH 25 /* If set, load watch registers */
#define TIF_SYSCALL_TRACEPOINT 26 /* syscall tracepoint instrumentation */
#define TIF_32BIT_FPREGS 27 /* 32-bit floating point registers */
#define TIF_SYSCALL_TRACE 31 /* syscall trace active */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@ -131,6 +132,7 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_32BIT_ADDR (1<<TIF_32BIT_ADDR)
#define _TIF_FPUBOUND (1<<TIF_FPUBOUND)
#define _TIF_LOAD_WATCH (1<<TIF_LOAD_WATCH)
#define _TIF_32BIT_FPREGS (1<<TIF_32BIT_FPREGS)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_WORK_SYSCALL_ENTRY (_TIF_NOHZ | _TIF_SYSCALL_TRACE | \

14
arch/mips/kernel/binfmt_elfo32.c
View file

@ -27,6 +27,18 @@ typedef elf_greg_t elf_gregset_t[ELF_NGREG];
typedef double elf_fpreg_t;
typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
/*
* In order to be sure that we don't attempt to execute an O32 binary which
* requires 64 bit FP (FR=1) on a system which does not support it we refuse
* to execute any binary which has bits specified by the following macro set
* in its ELF header flags.
*/
#ifdef CONFIG_MIPS_O32_FP64_SUPPORT
# define __MIPS_O32_FP64_MUST_BE_ZERO 0
#else
# define __MIPS_O32_FP64_MUST_BE_ZERO EF_MIPS_FP64
#endif
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
@ -43,6 +55,8 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
__res = 0; \
if (((__h->e_flags & EF_MIPS_ABI) != 0) && \
((__h->e_flags & EF_MIPS_ABI) != EF_MIPS_ABI_O32)) \
__res = 0; \
if (__h->e_flags & __MIPS_O32_FP64_MUST_BE_ZERO) \
__res = 0; \
\
__res; \

2
arch/mips/kernel/cpu-probe.c
View file

@ -112,7 +112,7 @@ static inline unsigned long cpu_get_fpu_id(void)
unsigned long tmp, fpu_id;
tmp = read_c0_status();
__enable_fpu();
__enable_fpu(FPU_AS_IS);
fpu_id = read_32bit_cp1_register(CP1_REVISION);
write_c0_status(tmp);
return fpu_id;

3
arch/mips/kernel/process.c
View file

@ -60,9 +60,6 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
/* New thread loses kernel privileges. */
status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
#ifdef CONFIG_64BIT
status |= test_thread_flag(TIF_32BIT_REGS) ? 0 : ST0_FR;
#endif
status |= KU_USER;
regs->cp0_status = status;
clear_used_math();

60
arch/mips/kernel/ptrace.c
View file

@ -137,13 +137,13 @@ int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
__enable_fpu();
__enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
__enable_fpu();
__enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
}
@ -408,6 +408,7 @@ long arch_ptrace(struct task_struct *child, long request,
/* Read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
struct pt_regs *regs;
fpureg_t *fregs;
unsigned long tmp = 0;
regs = task_pt_regs(child);
@ -418,26 +419,28 @@ long arch_ptrace(struct task_struct *child, long request,
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
if (tsk_used_math(child)) {
fpureg_t *fregs = get_fpu_regs(child);
if (!tsk_used_math(child)) {
/* FP not yet used */
tmp = -1;
break;
}
fregs = get_fpu_regs(child);
#ifdef CONFIG_32BIT
if (test_thread_flag(TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers - unless we're using r2k_switch.S.
*/
if (addr & 1)
tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
tmp = fregs[(addr & ~1) - 32] >> 32;
else
tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
#endif
#ifdef CONFIG_64BIT
tmp = fregs[addr - FPR_BASE];
#endif
} else {
tmp = -1; /* FP not yet used */
tmp = fregs[addr - 32];
break;
}
#endif
tmp = fregs[addr - FPR_BASE];
break;
case PC:
tmp = regs->cp0_epc;
@ -483,13 +486,13 @@ long arch_ptrace(struct task_struct *child, long request,
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
__enable_fpu();
__enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
__enable_fpu();
__enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
}
@ -554,22 +557,25 @@ long arch_ptrace(struct task_struct *child, long request,
child->thread.fpu.fcr31 = 0;
}
#ifdef CONFIG_32BIT
/*
* The odd registers are actually the high order bits
* of the values stored in the even registers - unless
* we're using r2k_switch.S.
*/
if (addr & 1) {
fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
} else {
fregs[addr - FPR_BASE] &= ~0xffffffffLL;
fregs[addr - FPR_BASE] |= data;
if (test_thread_flag(TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers - unless we're using r2k_switch.S.
*/
if (addr & 1) {
fregs[(addr & ~1) - FPR_BASE] &=
0xffffffff;
fregs[(addr & ~1) - FPR_BASE] |=
((u64)data) << 32;
} else {
fregs[addr - FPR_BASE] &= ~0xffffffffLL;
fregs[addr - FPR_BASE] |= data;
}
break;
}
#endif
#ifdef CONFIG_64BIT
fregs[addr - FPR_BASE] = data;
#endif
break;
}
case PC:

53
arch/mips/kernel/ptrace32.c
View file

@ -80,6 +80,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
/* Read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
struct pt_regs *regs;
fpureg_t *fregs;
unsigned int tmp;
regs = task_pt_regs(child);
@ -90,21 +91,25 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
if (tsk_used_math(child)) {
fpureg_t *fregs = get_fpu_regs(child);
if (!tsk_used_math(child)) {
/* FP not yet used */
tmp = -1;
break;
}
fregs = get_fpu_regs(child);
if (test_thread_flag(TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers - unless we're using r2k_switch.S.
*/
if (addr & 1)
tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
tmp = fregs[(addr & ~1) - 32] >> 32;
else
tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
} else {
tmp = -1; /* FP not yet used */
tmp = fregs[addr - 32];
break;
}
tmp = fregs[addr - FPR_BASE];
break;
case PC:
tmp = regs->cp0_epc;
@ -147,13 +152,13 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
__enable_fpu();
__enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
__enable_fpu();
__enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
}
@ -236,20 +241,24 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
sizeof(child->thread.fpu));
child->thread.fpu.fcr31 = 0;
}
/*
* The odd registers are actually the high order bits
* of the values stored in the even registers - unless
* we're using r2k_switch.S.
*/
if (addr & 1) {
fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
} else {
fregs[addr - FPR_BASE] &= ~0xffffffffLL;
/* Must cast, lest sign extension fill upper
bits! */
fregs[addr - FPR_BASE] |= (unsigned int)data;
if (test_thread_flag(TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers - unless we're using r2k_switch.S.
*/
if (addr & 1) {
fregs[(addr & ~1) - FPR_BASE] &=
0xffffffff;
fregs[(addr & ~1) - FPR_BASE] |=
((u64)data) << 32;
} else {
fregs[addr - FPR_BASE] &= ~0xffffffffLL;
fregs[addr - FPR_BASE] |= data;
}
break;
}
fregs[addr - FPR_BASE] = data;
break;
}
case PC:

74
arch/mips/kernel/r4k_fpu.S
View file

@ -35,7 +35,15 @@
LEAF(_save_fp_context)
cfc1 t1, fcr31
#ifdef CONFIG_64BIT
#if defined(CONFIG_64BIT) || defined(CONFIG_MIPS32_R2)
.set push
#ifdef CONFIG_MIPS32_R2
.set mips64r2
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip storing odd if FR=0
nop
#endif
/* Store the 16 odd double precision registers */
EX sdc1 $f1, SC_FPREGS+8(a0)
EX sdc1 $f3, SC_FPREGS+24(a0)
@ -53,6 +61,7 @@ LEAF(_save_fp_context)
EX sdc1 $f27, SC_FPREGS+216(a0)
EX sdc1 $f29, SC_FPREGS+232(a0)
EX sdc1 $f31, SC_FPREGS+248(a0)
1: .set pop
#endif
/* Store the 16 even double precision registers */
@ -82,7 +91,31 @@ LEAF(_save_fp_context)
LEAF(_save_fp_context32)
cfc1 t1, fcr31
EX sdc1 $f0, SC32_FPREGS+0(a0)
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip storing odd if FR=0
nop
/* Store the 16 odd double precision registers */
EX sdc1 $f1, SC32_FPREGS+8(a0)
EX sdc1 $f3, SC32_FPREGS+24(a0)
EX sdc1 $f5, SC32_FPREGS+40(a0)
EX sdc1 $f7, SC32_FPREGS+56(a0)
EX sdc1 $f9, SC32_FPREGS+72(a0)
EX sdc1 $f11, SC32_FPREGS+88(a0)
EX sdc1 $f13, SC32_FPREGS+104(a0)
EX sdc1 $f15, SC32_FPREGS+120(a0)
EX sdc1 $f17, SC32_FPREGS+136(a0)
EX sdc1 $f19, SC32_FPREGS+152(a0)
EX sdc1 $f21, SC32_FPREGS+168(a0)
EX sdc1 $f23, SC32_FPREGS+184(a0)
EX sdc1 $f25, SC32_FPREGS+200(a0)
EX sdc1 $f27, SC32_FPREGS+216(a0)
EX sdc1 $f29, SC32_FPREGS+232(a0)
EX sdc1 $f31, SC32_FPREGS+248(a0)
/* Store the 16 even double precision registers */
1: EX sdc1 $f0, SC32_FPREGS+0(a0)
EX sdc1 $f2, SC32_FPREGS+16(a0)
EX sdc1 $f4, SC32_FPREGS+32(a0)
EX sdc1 $f6, SC32_FPREGS+48(a0)
@ -114,7 +147,16 @@ LEAF(_save_fp_context32)
*/
LEAF(_restore_fp_context)
EX lw t0, SC_FPC_CSR(a0)
#ifdef CONFIG_64BIT
#if defined(CONFIG_64BIT) || defined(CONFIG_MIPS32_R2)
.set push
#ifdef CONFIG_MIPS32_R2
.set mips64r2
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip loading odd if FR=0
nop
#endif
EX ldc1 $f1, SC_FPREGS+8(a0)
EX ldc1 $f3, SC_FPREGS+24(a0)
EX ldc1 $f5, SC_FPREGS+40(a0)
@ -131,6 +173,7 @@ LEAF(_restore_fp_context)
EX ldc1 $f27, SC_FPREGS+216(a0)
EX ldc1 $f29, SC_FPREGS+232(a0)
EX ldc1 $f31, SC_FPREGS+248(a0)
1: .set pop
#endif
EX ldc1 $f0, SC_FPREGS+0(a0)
EX ldc1 $f2, SC_FPREGS+16(a0)
@ -157,7 +200,30 @@ LEAF(_restore_fp_context)
LEAF(_restore_fp_context32)
/* Restore an o32 sigcontext. */
EX lw t0, SC32_FPC_CSR(a0)
EX ldc1 $f0, SC32_FPREGS+0(a0)
mfc0 t0, CP0_STATUS
sll t0, t0, 5
bgez t0, 1f # skip loading odd if FR=0
nop
EX ldc1 $f1, SC32_FPREGS+8(a0)
EX ldc1 $f3, SC32_FPREGS+24(a0)
EX ldc1 $f5, SC32_FPREGS+40(a0)
EX ldc1 $f7, SC32_FPREGS+56(a0)
EX ldc1 $f9, SC32_FPREGS+72(a0)
EX ldc1 $f11, SC32_FPREGS+88(a0)
EX ldc1 $f13, SC32_FPREGS+104(a0)
EX ldc1 $f15, SC32_FPREGS+120(a0)
EX ldc1 $f17, SC32_FPREGS+136(a0)
EX ldc1 $f19, SC32_FPREGS+152(a0)
EX ldc1 $f21, SC32_FPREGS+168(a0)
EX ldc1 $f23, SC32_FPREGS+184(a0)
EX ldc1 $f25, SC32_FPREGS+200(a0)
EX ldc1 $f27, SC32_FPREGS+216(a0)
EX ldc1 $f29, SC32_FPREGS+232(a0)
EX ldc1 $f31, SC32_FPREGS+248(a0)
1: EX ldc1 $f0, SC32_FPREGS+0(a0)
EX ldc1 $f2, SC32_FPREGS+16(a0)
EX ldc1 $f4, SC32_FPREGS+32(a0)
EX ldc1 $f6, SC32_FPREGS+48(a0)

45
arch/mips/kernel/r4k_switch.S
View file

@ -123,7 +123,7 @@
* Save a thread's fp context.
*/
LEAF(_save_fp)
#ifdef CONFIG_64BIT
#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
mfc0 t0, CP0_STATUS
#endif
fpu_save_double a0 t0 t1 # clobbers t1
@ -134,7 +134,7 @@ LEAF(_save_fp)
* Restore a thread's fp context.
*/
LEAF(_restore_fp)
#ifdef CONFIG_64BIT
#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
mfc0 t0, CP0_STATUS
#endif
fpu_restore_double a0 t0 t1 # clobbers t1
@ -228,6 +228,47 @@ LEAF(_init_fpu)
mtc1 t1, $f29
mtc1 t1, $f30
mtc1 t1, $f31
#ifdef CONFIG_CPU_MIPS32_R2
.set push
.set mips64r2
sll t0, t0, 5 # is Status.FR set?
bgez t0, 1f # no: skip setting upper 32b
mthc1 t1, $f0
mthc1 t1, $f1
mthc1 t1, $f2
mthc1 t1, $f3
mthc1 t1, $f4
mthc1 t1, $f5
mthc1 t1, $f6
mthc1 t1, $f7
mthc1 t1, $f8
mthc1 t1, $f9
mthc1 t1, $f10
mthc1 t1, $f11
mthc1 t1, $f12
mthc1 t1, $f13
mthc1 t1, $f14
mthc1 t1, $f15
mthc1 t1, $f16
mthc1 t1, $f17
mthc1 t1, $f18
mthc1 t1, $f19
mthc1 t1, $f20
mthc1 t1, $f21
mthc1 t1, $f22
mthc1 t1, $f23
mthc1 t1, $f24
mthc1 t1, $f25
mthc1 t1, $f26
mthc1 t1, $f27
mthc1 t1, $f28
mthc1 t1, $f29
mthc1 t1, $f30
mthc1 t1, $f31
1: .set pop
#endif /* CONFIG_CPU_MIPS32_R2 */
#else
.set mips3
dmtc1 t1, $f0

10
arch/mips/kernel/signal.c
View file

@ -71,8 +71,9 @@ static int protected_save_fp_context(struct sigcontext __user *sc)
int err;
while (1) {
lock_fpu_owner();
own_fpu_inatomic(1);
err = save_fp_context(sc); /* this might fail */
err = own_fpu_inatomic(1);
if (!err)
err = save_fp_context(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
@ -91,8 +92,9 @@ static int protected_restore_fp_context(struct sigcontext __user *sc)
int err, tmp __maybe_unused;
while (1) {
lock_fpu_owner();
own_fpu_inatomic(0);
err = restore_fp_context(sc); /* this might fail */
err = own_fpu_inatomic(0);
if (!err)
err = restore_fp_context(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;

10
arch/mips/kernel/signal32.c
View file

@ -85,8 +85,9 @@ static int protected_save_fp_context32(struct sigcontext32 __user *sc)
int err;
while (1) {
lock_fpu_owner();
own_fpu_inatomic(1);
err = save_fp_context32(sc); /* this might fail */
err = own_fpu_inatomic(1);
if (!err)
err = save_fp_context32(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
@ -105,8 +106,9 @@ static int protected_restore_fp_context32(struct sigcontext32 __user *sc)
int err, tmp __maybe_unused;
while (1) {
lock_fpu_owner();
own_fpu_inatomic(0);
err = restore_fp_context32(sc); /* this might fail */
err = own_fpu_inatomic(0);
if (!err)
err = restore_fp_context32(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;

10
arch/mips/kernel/traps.c
View file

@ -1080,7 +1080,7 @@ asmlinkage void do_cpu(struct pt_regs *regs)
unsigned long old_epc, old31;
unsigned int opcode;
unsigned int cpid;
int status;
int status, err;
unsigned long __maybe_unused flags;
prev_state = exception_enter();
@ -1153,19 +1153,19 @@ asmlinkage void do_cpu(struct pt_regs *regs)
case 1:
if (used_math()) /* Using the FPU again. */
own_fpu(1);
err = own_fpu(1);
else { /* First time FPU user. */
init_fpu();
err = init_fpu();
set_used_math();
}
if (!raw_cpu_has_fpu) {
if (!raw_cpu_has_fpu || err) {
int sig;
void __user *fault_addr = NULL;
sig = fpu_emulator_cop1Handler(regs,
&current->thread.fpu,
0, &fault_addr);
if (!process_fpemu_return(sig, fault_addr))
if (!process_fpemu_return(sig, fault_addr) && !err)
mt_ase_fp_affinity();
}

10
arch/mips/math-emu/cp1emu.c
View file

@ -859,20 +859,20 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
* In the Linux kernel, we support selection of FPR format on the
* basis of the Status.FR bit. If an FPU is not present, the FR bit
* is hardwired to zero, which would imply a 32-bit FPU even for
* 64-bit CPUs so we rather look at TIF_32BIT_REGS.
* 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
* FPU emu is slow and bulky and optimizing this function offers fairly
* sizeable benefits so we try to be clever and make this function return
* a constant whenever possible, that is on 64-bit kernels without O32
* compatibility enabled and on 32-bit kernels.
* compatibility enabled and on 32-bit without 64-bit FPU support.
*/
static inline int cop1_64bit(struct pt_regs *xcp)
{
#if defined(CONFIG_64BIT) && !defined(CONFIG_MIPS32_O32)
return 1;
#elif defined(CONFIG_64BIT) && defined(CONFIG_MIPS32_O32)
return !test_thread_flag(TIF_32BIT_REGS);
#else
#elif defined(CONFIG_32BIT) && !defined(CONFIG_MIPS_O32_FP64_SUPPORT)
return 0;
#else
return !test_thread_flag(TIF_32BIT_FPREGS);
#endif
}

6
arch/mips/math-emu/kernel_linkage.c
View file

@ -89,8 +89,9 @@ int fpu_emulator_save_context32(struct sigcontext32 __user *sc)
{
int i;
int err = 0;
int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
for (i = 0; i < 32; i+=2) {
for (i = 0; i < 32; i += inc) {
err |=
__put_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
}
@ -103,8 +104,9 @@ int fpu_emulator_restore_context32(struct sigcontext32 __user *sc)
{
int i;
int err = 0;
int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
for (i = 0; i < 32; i+=2) {
for (i = 0; i < 32; i += inc) {
err |=
__get_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
}