diff --git a/arch/mips/include/asm/break.h b/arch/mips/include/asm/break.h index 25b980c91e7e..44437ed765e8 100644 --- a/arch/mips/include/asm/break.h +++ b/arch/mips/include/asm/break.h @@ -29,6 +29,7 @@ #define _BRK_THREADBP 11 /* For threads, user bp (used by debuggers) */ #define BRK_BUG 512 /* Used by BUG() */ #define BRK_KDB 513 /* Used in KDB_ENTER() */ +#define BRK_MEMU 514 /* Used by FPU emulator */ #define BRK_MULOVF 1023 /* Multiply overflow */ #endif /* __ASM_BREAK_H */ diff --git a/arch/mips/include/asm/fpu_emulator.h b/arch/mips/include/asm/fpu_emulator.h index 2731c38bd7ae..e5189572956c 100644 --- a/arch/mips/include/asm/fpu_emulator.h +++ b/arch/mips/include/asm/fpu_emulator.h @@ -23,6 +23,9 @@ #ifndef _ASM_FPU_EMULATOR_H #define _ASM_FPU_EMULATOR_H +#include +#include + struct mips_fpu_emulator_stats { unsigned int emulated; unsigned int loads; @@ -34,4 +37,18 @@ struct mips_fpu_emulator_stats { extern struct mips_fpu_emulator_stats fpuemustats; +extern int mips_dsemul(struct pt_regs *regs, mips_instruction ir, + unsigned long cpc); +extern int do_dsemulret(struct pt_regs *xcp); + +/* + * Instruction inserted following the badinst to further tag the sequence + */ +#define BD_COOKIE 0x0000bd36 /* tne $0, $0 with baggage */ + +/* + * Break instruction with special math emu break code set + */ +#define BREAK_MATH (0x0000000d | (BRK_MEMU << 16)) + #endif /* _ASM_FPU_EMULATOR_H */ diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 3f6de76d485d..353056110f2b 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -722,6 +723,21 @@ static void do_trap_or_bp(struct pt_regs *regs, unsigned int code, die_if_kernel("Kernel bug detected", regs); force_sig(SIGTRAP, current); break; + case BRK_MEMU: + /* + * Address errors may be deliberately induced by the FPU + * emulator to retake control of the CPU after executing the + * instruction in the delay slot of an emulated branch. + * + * Terminate if exception was recognized as a delay slot return + * otherwise handle as normal. + */ + if (do_dsemulret(regs)) + return; + + die_if_kernel("Math emu break/trap", regs); + force_sig(SIGTRAP, current); + break; default: scnprintf(b, sizeof(b), "%s instruction in kernel code", str); die_if_kernel(b, regs); diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c index 20709669e592..bf4c4a979abb 100644 --- a/arch/mips/kernel/unaligned.c +++ b/arch/mips/kernel/unaligned.c @@ -499,21 +499,9 @@ static void emulate_load_store_insn(struct pt_regs *regs, asmlinkage void do_ade(struct pt_regs *regs) { - extern int do_dsemulret(struct pt_regs *); unsigned int __user *pc; mm_segment_t seg; - /* - * Address errors may be deliberately induced by the FPU emulator to - * retake control of the CPU after executing the instruction in the - * delay slot of an emulated branch. - */ - /* Terminate if exception was recognized as a delay slot return */ - if (do_dsemulret(regs)) - return; - - /* Otherwise handle as normal */ - /* * Did we catch a fault trying to load an instruction? * Or are we running in MIPS16 mode? diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index 7ec0b217dfd3..890f77927d62 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -48,7 +48,6 @@ #include #include "ieee754.h" -#include "dsemul.h" /* Strap kernel emulator for full MIPS IV emulation */ @@ -346,9 +345,6 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx) /* cop control register rd -> gpr[rt] */ u32 value; - if (ir == CP1UNDEF) { - return do_dsemulret(xcp); - } if (MIPSInst_RD(ir) == FPCREG_CSR) { value = ctx->fcr31; value = (value & ~0x3) | mips_rm[value & 0x3]; diff --git a/arch/mips/math-emu/dsemul.c b/arch/mips/math-emu/dsemul.c index 653e325849e4..df7b9d928efc 100644 --- a/arch/mips/math-emu/dsemul.c +++ b/arch/mips/math-emu/dsemul.c @@ -18,7 +18,6 @@ #include #include "ieee754.h" -#include "dsemul.h" /* Strap kernel emulator for full MIPS IV emulation */ @@ -94,7 +93,7 @@ int mips_dsemul(struct pt_regs *regs, mips_instruction ir, unsigned long cpc) return SIGBUS; err = __put_user(ir, &fr->emul); - err |= __put_user((mips_instruction)BADINST, &fr->badinst); + err |= __put_user((mips_instruction)BREAK_MATH, &fr->badinst); err |= __put_user((mips_instruction)BD_COOKIE, &fr->cookie); err |= __put_user(cpc, &fr->epc); @@ -130,13 +129,13 @@ int do_dsemulret(struct pt_regs *xcp) /* * Do some sanity checking on the stackframe: * - * - Is the instruction pointed to by the EPC an BADINST? + * - Is the instruction pointed to by the EPC an BREAK_MATH? * - Is the following memory word the BD_COOKIE? */ err = __get_user(insn, &fr->badinst); err |= __get_user(cookie, &fr->cookie); - if (unlikely(err || (insn != BADINST) || (cookie != BD_COOKIE))) { + if (unlikely(err || (insn != BREAK_MATH) || (cookie != BD_COOKIE))) { fpuemustats.errors++; return 0; } diff --git a/arch/mips/math-emu/dsemul.h b/arch/mips/math-emu/dsemul.h deleted file mode 100644 index 091f0e76730f..000000000000 --- a/arch/mips/math-emu/dsemul.h +++ /dev/null @@ -1,17 +0,0 @@ -extern int mips_dsemul(struct pt_regs *regs, mips_instruction ir, unsigned long cpc); -extern int do_dsemulret(struct pt_regs *xcp); - -/* Instruction which will always cause an address error */ -#define AdELOAD 0x8c000001 /* lw $0,1($0) */ -/* Instruction which will plainly cause a CP1 exception when FPU is disabled */ -#define CP1UNDEF 0x44400001 /* cfc1 $0,$0 undef */ - -/* Instruction inserted following the badinst to further tag the sequence */ -#define BD_COOKIE 0x0000bd36 /* tne $0,$0 with baggage */ - -/* Setup which instruction to use for trampoline */ -#ifdef STANDALONE_EMULATOR -#define BADINST CP1UNDEF -#else -#define BADINST AdELOAD -#endif