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Date: Tue, 26 Oct 2010 03:55:41 +0100
From: David Howells <dhowells@...hat.com>
To: linux-am33-list@...hat.com
Cc: linux-kernel@...r.kernel.org,
Akira Takeuchi <takeuchi.akr@...panasonic.com>,
Kiyoshi Owada <owada.kiyoshi@...panasonic.com>
Subject: [PATCH 30/43] MN10300: Make the FPU operate in non-lazy mode under
SMP
From: Akira Takeuchi <takeuchi.akr@...panasonic.com>
Make the FPU operate in non-lazy mode under SMP so that when the process that
is currently using the FPU migrates to a different CPU, we don't have to ping
its previous CPU to flush the FPU context.
Signed-off-by: Akira Takeuchi <takeuchi.akr@...panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@...panasonic.com>
Signed-off-by: David Howells <dhowells@...hat.com>
---
arch/mn10300/Kconfig | 15 ++
arch/mn10300/include/asm/elf.h | 2
arch/mn10300/include/asm/exceptions.h | 1
arch/mn10300/include/asm/fpu.h | 157 ++++++++++++------
arch/mn10300/include/asm/processor.h | 1
arch/mn10300/include/asm/system.h | 16 ++
arch/mn10300/kernel/Makefile | 8 +
arch/mn10300/kernel/asm-offsets.c | 9 +
arch/mn10300/kernel/fpu-low.S | 265 +++++++++++++++++++------------
arch/mn10300/kernel/fpu-nofpu-low.S | 39 +++++
arch/mn10300/kernel/fpu-nofpu.c | 30 ++++
arch/mn10300/kernel/fpu.c | 141 +++++++---------
arch/mn10300/kernel/traps.c | 2
arch/mn10300/proc-mn103e010/proc-init.c | 2
14 files changed, 440 insertions(+), 248 deletions(-)
create mode 100644 arch/mn10300/kernel/fpu-nofpu-low.S
create mode 100644 arch/mn10300/kernel/fpu-nofpu.c
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 7bd920b..a1f334c 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -140,6 +140,21 @@ config FPU
default y
depends on MN10300_PROC_MN103E010
+config LAZY_SAVE_FPU
+ bool "Save FPU state lazily"
+ default y
+ depends on FPU && !SMP
+ help
+ Enable this to be lazy in the saving of the FPU state to the owning
+ task's thread struct. This is useful if most tasks on the system
+ don't use the FPU as only those tasks that use it will pass it
+ between them, and the state needn't be saved for a task that isn't
+ using it.
+
+ This can't be so easily used on SMP as the process that owns the FPU
+ state on a CPU may be currently running on another CPU, so for the
+ moment, it is disabled.
+
source "arch/mn10300/mm/Kconfig.cache"
config MN10300_TLB_USE_PIDR
diff --git a/arch/mn10300/include/asm/elf.h b/arch/mn10300/include/asm/elf.h
index e5fa97c..a30d220 100644
--- a/arch/mn10300/include/asm/elf.h
+++ b/arch/mn10300/include/asm/elf.h
@@ -47,8 +47,6 @@ typedef struct {
u_int32_t fpcr;
} elf_fpregset_t;
-extern int dump_fpu(struct pt_regs *, elf_fpregset_t *);
-
/*
* This is used to ensure we don't load something for the wrong architecture
*/
diff --git a/arch/mn10300/include/asm/exceptions.h b/arch/mn10300/include/asm/exceptions.h
index 3f3826a..7d8080b 100644
--- a/arch/mn10300/include/asm/exceptions.h
+++ b/arch/mn10300/include/asm/exceptions.h
@@ -101,7 +101,6 @@ extern asmlinkage void dtlb_aerror(void);
extern asmlinkage void raw_bus_error(void);
extern asmlinkage void double_fault(void);
extern asmlinkage int system_call(struct pt_regs *);
-extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code);
extern asmlinkage void nmi(struct pt_regs *, enum exception_code);
extern asmlinkage void uninitialised_exception(struct pt_regs *,
enum exception_code);
diff --git a/arch/mn10300/include/asm/fpu.h b/arch/mn10300/include/asm/fpu.h
index 64a2b83..b7625de 100644
--- a/arch/mn10300/include/asm/fpu.h
+++ b/arch/mn10300/include/asm/fpu.h
@@ -12,74 +12,125 @@
#ifndef _ASM_FPU_H
#define _ASM_FPU_H
-#include <asm/processor.h>
+#ifndef __ASSEMBLY__
+
+#include <linux/sched.h>
+#include <asm/exceptions.h>
#include <asm/sigcontext.h>
-#include <asm/user.h>
#ifdef __KERNEL__
-/* the task that owns the FPU state */
+extern asmlinkage void fpu_disabled(void);
+
+#ifdef CONFIG_FPU
+
+#ifdef CONFIG_LAZY_SAVE_FPU
+/* the task that currently owns the FPU state */
extern struct task_struct *fpu_state_owner;
+#endif
-#define set_using_fpu(tsk) \
-do { \
- (tsk)->thread.fpu_flags |= THREAD_USING_FPU; \
-} while (0)
+#if (THREAD_USING_FPU & ~0xff)
+#error THREAD_USING_FPU must be smaller than 0x100.
+#endif
-#define clear_using_fpu(tsk) \
-do { \
- (tsk)->thread.fpu_flags &= ~THREAD_USING_FPU; \
-} while (0)
+static inline void set_using_fpu(struct task_struct *tsk)
+{
+ asm volatile(
+ "bset %0,(0,%1)"
+ :
+ : "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags)
+ : "memory", "cc");
+}
-#define is_using_fpu(tsk) ((tsk)->thread.fpu_flags & THREAD_USING_FPU)
+static inline void clear_using_fpu(struct task_struct *tsk)
+{
+ asm volatile(
+ "bclr %0,(0,%1)"
+ :
+ : "i"(THREAD_USING_FPU), "a"(&tsk->thread.fpu_flags)
+ : "memory", "cc");
+}
-#define unlazy_fpu(tsk) \
-do { \
- preempt_disable(); \
- if (fpu_state_owner == (tsk)) \
- fpu_save(&tsk->thread.fpu_state); \
- preempt_enable(); \
-} while (0)
-
-#define exit_fpu() \
-do { \
- struct task_struct *__tsk = current; \
- preempt_disable(); \
- if (fpu_state_owner == __tsk) \
- fpu_state_owner = NULL; \
- preempt_enable(); \
-} while (0)
-
-#define flush_fpu() \
-do { \
- struct task_struct *__tsk = current; \
- preempt_disable(); \
- if (fpu_state_owner == __tsk) { \
- fpu_state_owner = NULL; \
- __tsk->thread.uregs->epsw &= ~EPSW_FE; \
- } \
- preempt_enable(); \
- clear_using_fpu(__tsk); \
-} while (0)
+#define is_using_fpu(tsk) ((tsk)->thread.fpu_flags & THREAD_USING_FPU)
-extern asmlinkage void fpu_init_state(void);
extern asmlinkage void fpu_kill_state(struct task_struct *);
-extern asmlinkage void fpu_disabled(struct pt_regs *, enum exception_code);
extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code);
-
-#ifdef CONFIG_FPU
+extern asmlinkage void fpu_invalid_op(struct pt_regs *, enum exception_code);
+extern asmlinkage void fpu_init_state(void);
extern asmlinkage void fpu_save(struct fpu_state_struct *);
-extern asmlinkage void fpu_restore(struct fpu_state_struct *);
-#else
-#define fpu_save(a)
-#define fpu_restore(a)
-#endif /* CONFIG_FPU */
-
-/*
- * signal frame handlers
- */
extern int fpu_setup_sigcontext(struct fpucontext *buf);
extern int fpu_restore_sigcontext(struct fpucontext *buf);
+static inline void unlazy_fpu(struct task_struct *tsk)
+{
+ preempt_disable();
+#ifndef CONFIG_LAZY_SAVE_FPU
+ if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
+ fpu_save(&tsk->thread.fpu_state);
+ tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
+ tsk->thread.uregs->epsw &= ~EPSW_FE;
+ }
+#else
+ if (fpu_state_owner == tsk)
+ fpu_save(&tsk->thread.fpu_state);
+#endif
+ preempt_enable();
+}
+
+static inline void exit_fpu(void)
+{
+#ifdef CONFIG_LAZY_SAVE_FPU
+ struct task_struct *tsk = current;
+
+ preempt_disable();
+ if (fpu_state_owner == tsk)
+ fpu_state_owner = NULL;
+ preempt_enable();
+#endif
+}
+
+static inline void flush_fpu(void)
+{
+ struct task_struct *tsk = current;
+
+ preempt_disable();
+#ifndef CONFIG_LAZY_SAVE_FPU
+ if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
+ tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
+ tsk->thread.uregs->epsw &= ~EPSW_FE;
+ }
+#else
+ if (fpu_state_owner == tsk) {
+ fpu_state_owner = NULL;
+ tsk->thread.uregs->epsw &= ~EPSW_FE;
+ }
+#endif
+ preempt_enable();
+ clear_using_fpu(tsk);
+}
+
+#else /* CONFIG_FPU */
+
+extern asmlinkage
+void unexpected_fpu_exception(struct pt_regs *, enum exception_code);
+#define fpu_invalid_op unexpected_fpu_exception
+#define fpu_exception unexpected_fpu_exception
+
+struct task_struct;
+struct fpu_state_struct;
+static inline bool is_using_fpu(struct task_struct *tsk) { return false; }
+static inline void set_using_fpu(struct task_struct *tsk) {}
+static inline void clear_using_fpu(struct task_struct *tsk) {}
+static inline void fpu_init_state(void) {}
+static inline void fpu_save(struct fpu_state_struct *s) {}
+static inline void fpu_kill_state(struct task_struct *tsk) {}
+static inline void unlazy_fpu(struct task_struct *tsk) {}
+static inline void exit_fpu(void) {}
+static inline void flush_fpu(void) {}
+static inline int fpu_setup_sigcontext(struct fpucontext *buf) { return 0; }
+static inline int fpu_restore_sigcontext(struct fpucontext *buf) { return 0; }
+#endif /* CONFIG_FPU */
+
#endif /* __KERNEL__ */
+#endif /* !__ASSEMBLY__ */
#endif /* _ASM_FPU_H */
diff --git a/arch/mn10300/include/asm/processor.h b/arch/mn10300/include/asm/processor.h
index fd96c18..0032fc7 100644
--- a/arch/mn10300/include/asm/processor.h
+++ b/arch/mn10300/include/asm/processor.h
@@ -95,6 +95,7 @@ struct thread_struct {
struct pt_regs *__frame;
unsigned long fpu_flags;
#define THREAD_USING_FPU 0x00000001 /* T if this task is using the FPU */
+#define THREAD_HAS_FPU 0x00000002 /* T if this task owns the FPU right now */
struct fpu_state_struct fpu_state;
};
diff --git a/arch/mn10300/include/asm/system.h b/arch/mn10300/include/asm/system.h
index 9f7c7e1..3c272a1 100644
--- a/arch/mn10300/include/asm/system.h
+++ b/arch/mn10300/include/asm/system.h
@@ -19,6 +19,21 @@
#include <linux/kernel.h>
#include <linux/irqflags.h>
+#if !defined(CONFIG_LAZY_SAVE_FPU)
+struct fpu_state_struct;
+extern asmlinkage void fpu_save(struct fpu_state_struct *);
+#define switch_fpu(prev, next) \
+ do { \
+ if ((prev)->thread.fpu_flags & THREAD_HAS_FPU) { \
+ (prev)->thread.fpu_flags &= ~THREAD_HAS_FPU; \
+ (prev)->thread.uregs->epsw &= ~EPSW_FE; \
+ fpu_save(&(prev)->thread.fpu_state); \
+ } \
+ } while (0)
+#else
+#define switch_fpu(prev, next) do {} while (0)
+#endif
+
struct task_struct;
struct thread_struct;
@@ -30,6 +45,7 @@ struct task_struct *__switch_to(struct thread_struct *prev,
/* context switching is now performed out-of-line in switch_to.S */
#define switch_to(prev, next, last) \
do { \
+ switch_fpu(prev, next); \
current->thread.wchan = (u_long) __builtin_return_address(0); \
(last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \
mb(); \
diff --git a/arch/mn10300/kernel/Makefile b/arch/mn10300/kernel/Makefile
index c4289e3..9902235 100644
--- a/arch/mn10300/kernel/Makefile
+++ b/arch/mn10300/kernel/Makefile
@@ -3,13 +3,15 @@
#
extra-y := head.o init_task.o vmlinux.lds
-obj-y := process.o signal.o entry.o fpu.o traps.o irq.o \
+fpu-obj-y := fpu-nofpu.o fpu-nofpu-low.o
+fpu-obj-$(CONFIG_FPU) := fpu.o fpu-low.o
+
+obj-y := process.o signal.o entry.o traps.o irq.o \
ptrace.o setup.o time.o sys_mn10300.o io.o kthread.o \
- switch_to.o mn10300_ksyms.o kernel_execve.o
+ switch_to.o mn10300_ksyms.o kernel_execve.o $(fpu-obj-y)
obj-$(CONFIG_MN10300_WD_TIMER) += mn10300-watchdog.o mn10300-watchdog-low.o
-obj-$(CONFIG_FPU) += fpu-low.o
obj-$(CONFIG_MN10300_TTYSM) += mn10300-serial.o mn10300-serial-low.o \
mn10300-debug.o
diff --git a/arch/mn10300/kernel/asm-offsets.c b/arch/mn10300/kernel/asm-offsets.c
index 02dc7e4..78e290e 100644
--- a/arch/mn10300/kernel/asm-offsets.c
+++ b/arch/mn10300/kernel/asm-offsets.c
@@ -67,6 +67,15 @@ void foo(void)
OFFSET(THREAD_A3, thread_struct, a3);
OFFSET(THREAD_USP, thread_struct, usp);
OFFSET(THREAD_FRAME, thread_struct, __frame);
+#ifdef CONFIG_FPU
+ OFFSET(THREAD_FPU_FLAGS, thread_struct, fpu_flags);
+ OFFSET(THREAD_FPU_STATE, thread_struct, fpu_state);
+ DEFINE(__THREAD_USING_FPU, THREAD_USING_FPU);
+ DEFINE(__THREAD_HAS_FPU, THREAD_HAS_FPU);
+#endif /* CONFIG_FPU */
+ BLANK();
+
+ OFFSET(TASK_THREAD, task_struct, thread);
BLANK();
DEFINE(CLONE_VM_asm, CLONE_VM);
diff --git a/arch/mn10300/kernel/fpu-low.S b/arch/mn10300/kernel/fpu-low.S
index 96cfd47..78df25c 100644
--- a/arch/mn10300/kernel/fpu-low.S
+++ b/arch/mn10300/kernel/fpu-low.S
@@ -8,25 +8,14 @@
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
+#include <linux/linkage.h>
#include <asm/cpu-regs.h>
+#include <asm/smp.h>
+#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
+#include <asm/frame.inc>
-###############################################################################
-#
-# void fpu_init_state(void)
-# - initialise the FPU
-#
-###############################################################################
- .globl fpu_init_state
- .type fpu_init_state,@function
-fpu_init_state:
- mov epsw,d0
- or EPSW_FE,epsw
-
-#ifdef CONFIG_MN10300_PROC_MN103E010
- nop
- nop
- nop
-#endif
+.macro FPU_INIT_STATE_ALL
fmov 0,fs0
fmov fs0,fs1
fmov fs0,fs2
@@ -60,7 +49,100 @@ fpu_init_state:
fmov fs0,fs30
fmov fs0,fs31
fmov FPCR_INIT,fpcr
+.endm
+
+.macro FPU_SAVE_ALL areg,dreg
+ fmov fs0,(\areg+)
+ fmov fs1,(\areg+)
+ fmov fs2,(\areg+)
+ fmov fs3,(\areg+)
+ fmov fs4,(\areg+)
+ fmov fs5,(\areg+)
+ fmov fs6,(\areg+)
+ fmov fs7,(\areg+)
+ fmov fs8,(\areg+)
+ fmov fs9,(\areg+)
+ fmov fs10,(\areg+)
+ fmov fs11,(\areg+)
+ fmov fs12,(\areg+)
+ fmov fs13,(\areg+)
+ fmov fs14,(\areg+)
+ fmov fs15,(\areg+)
+ fmov fs16,(\areg+)
+ fmov fs17,(\areg+)
+ fmov fs18,(\areg+)
+ fmov fs19,(\areg+)
+ fmov fs20,(\areg+)
+ fmov fs21,(\areg+)
+ fmov fs22,(\areg+)
+ fmov fs23,(\areg+)
+ fmov fs24,(\areg+)
+ fmov fs25,(\areg+)
+ fmov fs26,(\areg+)
+ fmov fs27,(\areg+)
+ fmov fs28,(\areg+)
+ fmov fs29,(\areg+)
+ fmov fs30,(\areg+)
+ fmov fs31,(\areg+)
+ fmov fpcr,\dreg
+ mov \dreg,(\areg)
+.endm
+
+.macro FPU_RESTORE_ALL areg,dreg
+ fmov (\areg+),fs0
+ fmov (\areg+),fs1
+ fmov (\areg+),fs2
+ fmov (\areg+),fs3
+ fmov (\areg+),fs4
+ fmov (\areg+),fs5
+ fmov (\areg+),fs6
+ fmov (\areg+),fs7
+ fmov (\areg+),fs8
+ fmov (\areg+),fs9
+ fmov (\areg+),fs10
+ fmov (\areg+),fs11
+ fmov (\areg+),fs12
+ fmov (\areg+),fs13
+ fmov (\areg+),fs14
+ fmov (\areg+),fs15
+ fmov (\areg+),fs16
+ fmov (\areg+),fs17
+ fmov (\areg+),fs18
+ fmov (\areg+),fs19
+ fmov (\areg+),fs20
+ fmov (\areg+),fs21
+ fmov (\areg+),fs22
+ fmov (\areg+),fs23
+ fmov (\areg+),fs24
+ fmov (\areg+),fs25
+ fmov (\areg+),fs26
+ fmov (\areg+),fs27
+ fmov (\areg+),fs28
+ fmov (\areg+),fs29
+ fmov (\areg+),fs30
+ fmov (\areg+),fs31
+ mov (\areg),\dreg
+ fmov \dreg,fpcr
+.endm
+###############################################################################
+#
+# void fpu_init_state(void)
+# - initialise the FPU
+#
+###############################################################################
+ .globl fpu_init_state
+ .type fpu_init_state,@function
+fpu_init_state:
+ mov epsw,d0
+ or EPSW_FE,epsw
+
+#ifdef CONFIG_MN10300_PROC_MN103E010
+ nop
+ nop
+ nop
+#endif
+ FPU_INIT_STATE_ALL
#ifdef CONFIG_MN10300_PROC_MN103E010
nop
nop
@@ -89,40 +171,7 @@ fpu_save:
nop
#endif
mov d0,a0
- fmov fs0,(a0+)
- fmov fs1,(a0+)
- fmov fs2,(a0+)
- fmov fs3,(a0+)
- fmov fs4,(a0+)
- fmov fs5,(a0+)
- fmov fs6,(a0+)
- fmov fs7,(a0+)
- fmov fs8,(a0+)
- fmov fs9,(a0+)
- fmov fs10,(a0+)
- fmov fs11,(a0+)
- fmov fs12,(a0+)
- fmov fs13,(a0+)
- fmov fs14,(a0+)
- fmov fs15,(a0+)
- fmov fs16,(a0+)
- fmov fs17,(a0+)
- fmov fs18,(a0+)
- fmov fs19,(a0+)
- fmov fs20,(a0+)
- fmov fs21,(a0+)
- fmov fs22,(a0+)
- fmov fs23,(a0+)
- fmov fs24,(a0+)
- fmov fs25,(a0+)
- fmov fs26,(a0+)
- fmov fs27,(a0+)
- fmov fs28,(a0+)
- fmov fs29,(a0+)
- fmov fs30,(a0+)
- fmov fs31,(a0+)
- fmov fpcr,d0
- mov d0,(a0)
+ FPU_SAVE_ALL a0,d0
#ifdef CONFIG_MN10300_PROC_MN103E010
nop
nop
@@ -135,63 +184,75 @@ fpu_save:
###############################################################################
#
-# void fpu_restore(struct fpu_state_struct *)
-# - restore the fpu state
-# - note that an FPU Operational exception might occur during this process
+# void fpu_disabled(void)
+# - handle an exception due to the FPU being disabled
+# when CONFIG_FPU is enabled
#
###############################################################################
- .globl fpu_restore
- .type fpu_restore,@function
-fpu_restore:
- mov epsw,d1
- or EPSW_FE,epsw /* enable the FPU so we can access it */
-
-#ifdef CONFIG_MN10300_PROC_MN103E010
+ .type fpu_disabled,@function
+ .globl fpu_disabled
+fpu_disabled:
+ or EPSW_nAR|EPSW_FE,epsw
nop
nop
-#endif
- mov d0,a0
- fmov (a0+),fs0
- fmov (a0+),fs1
- fmov (a0+),fs2
- fmov (a0+),fs3
- fmov (a0+),fs4
- fmov (a0+),fs5
- fmov (a0+),fs6
- fmov (a0+),fs7
- fmov (a0+),fs8
- fmov (a0+),fs9
- fmov (a0+),fs10
- fmov (a0+),fs11
- fmov (a0+),fs12
- fmov (a0+),fs13
- fmov (a0+),fs14
- fmov (a0+),fs15
- fmov (a0+),fs16
- fmov (a0+),fs17
- fmov (a0+),fs18
- fmov (a0+),fs19
- fmov (a0+),fs20
- fmov (a0+),fs21
- fmov (a0+),fs22
- fmov (a0+),fs23
- fmov (a0+),fs24
- fmov (a0+),fs25
- fmov (a0+),fs26
- fmov (a0+),fs27
- fmov (a0+),fs28
- fmov (a0+),fs29
- fmov (a0+),fs30
- fmov (a0+),fs31
- mov (a0),d0
- fmov d0,fpcr
-#ifdef CONFIG_MN10300_PROC_MN103E010
nop
+
+ mov sp,a1
+ mov (a1),d1 /* get epsw of user context */
+ and ~(THREAD_SIZE-1),a1 /* a1: (thread_info *ti) */
+ mov (TI_task,a1),a2 /* a2: (task_struct *tsk) */
+ btst EPSW_nSL,d1
+ beq fpu_used_in_kernel
+
+ or EPSW_FE,d1
+ mov d1,(sp)
+ mov (TASK_THREAD+THREAD_FPU_FLAGS,a2),d1
+#ifndef CONFIG_LAZY_SAVE_FPU
+ or __THREAD_HAS_FPU,d1
+ mov d1,(TASK_THREAD+THREAD_FPU_FLAGS,a2)
+#else /* !CONFIG_LAZY_SAVE_FPU */
+ mov (fpu_state_owner),a0
+ cmp 0,a0
+ beq fpu_regs_save_end
+
+ mov (TASK_THREAD+THREAD_UREGS,a0),a1
+ add TASK_THREAD+THREAD_FPU_STATE,a0
+ FPU_SAVE_ALL a0,d0
+
+ mov (REG_EPSW,a1),d0
+ and ~EPSW_FE,d0
+ mov d0,(REG_EPSW,a1)
+
+fpu_regs_save_end:
+ mov a2,(fpu_state_owner)
+#endif /* !CONFIG_LAZY_SAVE_FPU */
+
+ btst __THREAD_USING_FPU,d1
+ beq fpu_regs_init
+ add TASK_THREAD+THREAD_FPU_STATE,a2
+ FPU_RESTORE_ALL a2,d0
+ rti
+
+fpu_regs_init:
+ FPU_INIT_STATE_ALL
+ add TASK_THREAD+THREAD_FPU_FLAGS,a2
+ bset __THREAD_USING_FPU,(0,a2)
+ rti
+
+fpu_used_in_kernel:
+ and ~(EPSW_nAR|EPSW_FE),epsw
nop
nop
-#endif
- mov d1,epsw
- ret [],0
+ add -4,sp
+ SAVE_ALL
+ mov -1,d0
+ mov d0,(REG_ORIG_D0,fp)
+
+ and ~EPSW_NMID,epsw
+
+ mov fp,d0
+ call fpu_disabled_in_kernel[],0
+ jmp ret_from_exception
- .size fpu_restore,.-fpu_restore
+ .size fpu_disabled,.-fpu_disabled
diff --git a/arch/mn10300/kernel/fpu-nofpu-low.S b/arch/mn10300/kernel/fpu-nofpu-low.S
new file mode 100644
index 0000000..7ea087a
--- /dev/null
+++ b/arch/mn10300/kernel/fpu-nofpu-low.S
@@ -0,0 +1,39 @@
+/* MN10300 Low level FPU management operations
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@...hat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/linkage.h>
+#include <asm/cpu-regs.h>
+#include <asm/smp.h>
+#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
+#include <asm/frame.inc>
+
+###############################################################################
+#
+# void fpu_disabled(void)
+# - handle an exception due to the FPU being disabled
+# when CONFIG_FPU is disabled
+#
+###############################################################################
+ .type fpu_disabled,@function
+ .globl fpu_disabled
+fpu_disabled:
+ add -4,sp
+ SAVE_ALL
+ mov -1,d0
+ mov d0,(REG_ORIG_D0,fp)
+
+ and ~EPSW_NMID,epsw
+
+ mov fp,d0
+ call unexpected_fpu_exception[],0
+ jmp ret_from_exception
+
+ .size fpu_disabled,.-fpu_disabled
diff --git a/arch/mn10300/kernel/fpu-nofpu.c b/arch/mn10300/kernel/fpu-nofpu.c
new file mode 100644
index 0000000..31c765b
--- /dev/null
+++ b/arch/mn10300/kernel/fpu-nofpu.c
@@ -0,0 +1,30 @@
+/* MN10300 FPU management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@...hat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <asm/fpu.h>
+
+/*
+ * handle an FPU operational exception
+ * - there's a possibility that if the FPU is asynchronous, the signal might
+ * be meant for a process other than the current one
+ */
+asmlinkage
+void unexpected_fpu_exception(struct pt_regs *regs, enum exception_code code)
+{
+ panic("An FPU exception was received, but there's no FPU enabled.");
+}
+
+/*
+ * fill in the FPU structure for a core dump
+ */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpreg)
+{
+ return 0; /* not valid */
+}
diff --git a/arch/mn10300/kernel/fpu.c b/arch/mn10300/kernel/fpu.c
index e705f25..5f9c3fa 100644
--- a/arch/mn10300/kernel/fpu.c
+++ b/arch/mn10300/kernel/fpu.c
@@ -12,56 +12,19 @@
#include <asm/fpu.h>
#include <asm/elf.h>
#include <asm/exceptions.h>
+#include <asm/system.h>
+#ifdef CONFIG_LAZY_SAVE_FPU
struct task_struct *fpu_state_owner;
+#endif
/*
- * handle an exception due to the FPU being disabled
+ * error functions in FPU disabled exception
*/
-asmlinkage void fpu_disabled(struct pt_regs *regs, enum exception_code code)
+asmlinkage void fpu_disabled_in_kernel(struct pt_regs *regs)
{
- struct task_struct *tsk = current;
-
- if (!user_mode(regs))
- die_if_no_fixup("An FPU Disabled exception happened in"
- " kernel space\n",
- regs, code);
-
-#ifdef CONFIG_FPU
- preempt_disable();
-
- /* transfer the last process's FPU state to memory */
- if (fpu_state_owner) {
- fpu_save(&fpu_state_owner->thread.fpu_state);
- fpu_state_owner->thread.uregs->epsw &= ~EPSW_FE;
- }
-
- /* the current process now owns the FPU state */
- fpu_state_owner = tsk;
- regs->epsw |= EPSW_FE;
-
- /* load the FPU with the current process's FPU state or invent a new
- * clean one if the process doesn't have one */
- if (is_using_fpu(tsk)) {
- fpu_restore(&tsk->thread.fpu_state);
- } else {
- fpu_init_state();
- set_using_fpu(tsk);
- }
-
- preempt_enable();
-#else
- {
- siginfo_t info;
-
- info.si_signo = SIGFPE;
- info.si_errno = 0;
- info.si_addr = (void *) tsk->thread.uregs->pc;
- info.si_code = FPE_FLTINV;
-
- force_sig_info(SIGFPE, &info, tsk);
- }
-#endif /* CONFIG_FPU */
+ die_if_no_fixup("An FPU Disabled exception happened in kernel space\n",
+ regs, EXCEP_FPU_DISABLED);
}
/*
@@ -71,15 +34,16 @@ asmlinkage void fpu_disabled(struct pt_regs *regs, enum exception_code code)
*/
asmlinkage void fpu_exception(struct pt_regs *regs, enum exception_code code)
{
- struct task_struct *tsk = fpu_state_owner;
+ struct task_struct *tsk = current;
siginfo_t info;
+ u32 fpcr;
if (!user_mode(regs))
die_if_no_fixup("An FPU Operation exception happened in"
" kernel space\n",
regs, code);
- if (!tsk)
+ if (!is_using_fpu(tsk))
die_if_no_fixup("An FPU Operation exception happened,"
" but the FPU is not in use",
regs, code);
@@ -89,48 +53,45 @@ asmlinkage void fpu_exception(struct pt_regs *regs, enum exception_code code)
info.si_addr = (void *) tsk->thread.uregs->pc;
info.si_code = FPE_FLTINV;
-#ifdef CONFIG_FPU
- {
- u32 fpcr;
+ unlazy_fpu(tsk);
- /* get FPCR (we need to enable the FPU whilst we do this) */
- asm volatile(" or %1,epsw \n"
-#ifdef CONFIG_MN10300_PROC_MN103E010
- " nop \n"
- " nop \n"
- " nop \n"
-#endif
- " fmov fpcr,%0 \n"
-#ifdef CONFIG_MN10300_PROC_MN103E010
- " nop \n"
- " nop \n"
- " nop \n"
-#endif
- " and %2,epsw \n"
- : "=&d"(fpcr)
- : "i"(EPSW_FE), "i"(~EPSW_FE)
- );
-
- if (fpcr & FPCR_EC_Z)
- info.si_code = FPE_FLTDIV;
- else if (fpcr & FPCR_EC_O)
- info.si_code = FPE_FLTOVF;
- else if (fpcr & FPCR_EC_U)
- info.si_code = FPE_FLTUND;
- else if (fpcr & FPCR_EC_I)
- info.si_code = FPE_FLTRES;
- }
-#endif
+ fpcr = tsk->thread.fpu_state.fpcr;
+
+ if (fpcr & FPCR_EC_Z)
+ info.si_code = FPE_FLTDIV;
+ else if (fpcr & FPCR_EC_O)
+ info.si_code = FPE_FLTOVF;
+ else if (fpcr & FPCR_EC_U)
+ info.si_code = FPE_FLTUND;
+ else if (fpcr & FPCR_EC_I)
+ info.si_code = FPE_FLTRES;
force_sig_info(SIGFPE, &info, tsk);
}
/*
+ * handle an FPU invalid_op exception
+ * - Derived from DO_EINFO() macro in arch/mn10300/kernel/traps.c
+ */
+asmlinkage void fpu_invalid_op(struct pt_regs *regs, enum exception_code code)
+{
+ siginfo_t info;
+
+ if (!user_mode(regs))
+ die_if_no_fixup("FPU invalid opcode", regs, code);
+
+ info.si_signo = SIGILL;
+ info.si_errno = 0;
+ info.si_code = ILL_COPROC;
+ info.si_addr = (void *) regs->pc;
+ force_sig_info(info.si_signo, &info, current);
+}
+
+/*
* save the FPU state to a signal context
*/
int fpu_setup_sigcontext(struct fpucontext *fpucontext)
{
-#ifdef CONFIG_FPU
struct task_struct *tsk = current;
if (!is_using_fpu(tsk))
@@ -142,11 +103,19 @@ int fpu_setup_sigcontext(struct fpucontext *fpucontext)
*/
preempt_disable();
+#ifndef CONFIG_LAZY_SAVE_FPU
+ if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
+ fpu_save(&tsk->thread.fpu_state);
+ tsk->thread.uregs->epsw &= ~EPSW_FE;
+ tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
+ }
+#else /* !CONFIG_LAZY_SAVE_FPU */
if (fpu_state_owner == tsk) {
fpu_save(&tsk->thread.fpu_state);
fpu_state_owner->thread.uregs->epsw &= ~EPSW_FE;
fpu_state_owner = NULL;
}
+#endif /* !CONFIG_LAZY_SAVE_FPU */
preempt_enable();
@@ -161,9 +130,6 @@ int fpu_setup_sigcontext(struct fpucontext *fpucontext)
return -1;
return 1;
-#else
- return 0;
-#endif
}
/*
@@ -171,17 +137,23 @@ int fpu_setup_sigcontext(struct fpucontext *fpucontext)
*/
void fpu_kill_state(struct task_struct *tsk)
{
-#ifdef CONFIG_FPU
/* disown anything left in the FPU */
preempt_disable();
+#ifndef CONFIG_LAZY_SAVE_FPU
+ if (tsk->thread.fpu_flags & THREAD_HAS_FPU) {
+ tsk->thread.uregs->epsw &= ~EPSW_FE;
+ tsk->thread.fpu_flags &= ~THREAD_HAS_FPU;
+ }
+#else /* !CONFIG_LAZY_SAVE_FPU */
if (fpu_state_owner == tsk) {
fpu_state_owner->thread.uregs->epsw &= ~EPSW_FE;
fpu_state_owner = NULL;
}
+#endif /* !CONFIG_LAZY_SAVE_FPU */
preempt_enable();
-#endif
+
/* we no longer have a valid current FPU state */
clear_using_fpu(tsk);
}
@@ -195,8 +167,7 @@ int fpu_restore_sigcontext(struct fpucontext *fpucontext)
int ret;
/* load up the old FPU state */
- ret = copy_from_user(&tsk->thread.fpu_state,
- fpucontext,
+ ret = copy_from_user(&tsk->thread.fpu_state, fpucontext,
min(sizeof(struct fpu_state_struct),
sizeof(struct fpucontext)));
if (!ret)
diff --git a/arch/mn10300/kernel/traps.c b/arch/mn10300/kernel/traps.c
index c7257a1..716a221 100644
--- a/arch/mn10300/kernel/traps.c
+++ b/arch/mn10300/kernel/traps.c
@@ -101,7 +101,6 @@ DO_EINFO(SIGILL, {}, "invalid opcode", invalid_op, ILL_ILLOPC);
DO_EINFO(SIGILL, {}, "invalid ex opcode", invalid_exop, ILL_ILLOPC);
DO_EINFO(SIGBUS, {}, "invalid address", mem_error, BUS_ADRERR);
DO_EINFO(SIGBUS, {}, "bus error", bus_error, BUS_ADRERR);
-DO_EINFO(SIGILL, {}, "FPU invalid opcode", fpu_invalid_op, ILL_COPROC);
DO_ERROR(SIGTRAP,
#ifndef CONFIG_MN10300_USING_JTAG
@@ -561,7 +560,6 @@ void __init trap_init(void)
set_excp_vector(EXCEP_PRIVINSACC, insn_acc_error);
set_excp_vector(EXCEP_PRIVDATACC, data_acc_error);
set_excp_vector(EXCEP_DATINSACC, insn_acc_error);
- set_excp_vector(EXCEP_FPU_DISABLED, fpu_disabled);
set_excp_vector(EXCEP_FPU_UNIMPINS, fpu_invalid_op);
set_excp_vector(EXCEP_FPU_OPERATION, fpu_exception);
diff --git a/arch/mn10300/proc-mn103e010/proc-init.c b/arch/mn10300/proc-mn103e010/proc-init.c
index 9a482ef..0cee787 100644
--- a/arch/mn10300/proc-mn103e010/proc-init.c
+++ b/arch/mn10300/proc-mn103e010/proc-init.c
@@ -9,6 +9,7 @@
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/kernel.h>
+#include <asm/fpu.h>
#include <asm/rtc.h>
/*
@@ -28,6 +29,7 @@ asmlinkage void __init processor_init(void)
__set_intr_stub(EXCEP_DAERROR, dtlb_aerror);
__set_intr_stub(EXCEP_BUSERROR, raw_bus_error);
__set_intr_stub(EXCEP_DOUBLE_FAULT, double_fault);
+ __set_intr_stub(EXCEP_FPU_DISABLED, fpu_disabled);
__set_intr_stub(EXCEP_SYSCALL0, system_call);
__set_intr_stub(EXCEP_NMI, nmi_handler);
--
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