From 4b565680d16300acab0ff167e24f0ea289a6bd5d Mon Sep 17 00:00:00 2001 From: Takashi YOSHII Date: Wed, 27 Sep 2006 17:15:32 +0900 Subject: sh: math-emu support This implements initial math-emu support, aimed primarily at SH-3. Signed-off-by: Takashi YOSHII Signed-off-by: Paul Mundt --- arch/sh/kernel/traps.c | 164 +++++++++++++++++++++++++++++++++++++------------ 1 file changed, 125 insertions(+), 39 deletions(-) (limited to 'arch/sh/kernel/traps.c') diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c index 21bef1b5f991..95c810b3c97e 100644 --- a/arch/sh/kernel/traps.c +++ b/arch/sh/kernel/traps.c @@ -36,40 +36,15 @@ #ifdef CONFIG_SH_KGDB #include -#define CHK_REMOTE_DEBUG(regs) \ -{ \ - if ((kgdb_debug_hook != (kgdb_debug_hook_t *) NULL) && (!user_mode(regs))) \ - { \ - (*kgdb_debug_hook)(regs); \ - } \ +#define CHK_REMOTE_DEBUG(regs) \ +{ \ + if (kgdb_debug_hook && !user_mode(regs))\ + (*kgdb_debug_hook)(regs); \ } #else #define CHK_REMOTE_DEBUG(regs) #endif -#define DO_ERROR(trapnr, signr, str, name, tsk) \ -asmlinkage void do_##name(unsigned long r4, unsigned long r5, \ - unsigned long r6, unsigned long r7, \ - struct pt_regs regs) \ -{ \ - unsigned long error_code; \ - \ - /* Check if it's a DSP instruction */ \ - if (is_dsp_inst(®s)) { \ - /* Enable DSP mode, and restart instruction. */ \ - regs.sr |= SR_DSP; \ - return; \ - } \ - \ - asm volatile("stc r2_bank, %0": "=r" (error_code)); \ - local_irq_enable(); \ - tsk->thread.error_code = error_code; \ - tsk->thread.trap_no = trapnr; \ - CHK_REMOTE_DEBUG(®s); \ - force_sig(signr, tsk); \ - die_if_no_fixup(str,®s,error_code); \ -} - #ifdef CONFIG_CPU_SH2 #define TRAP_RESERVED_INST 4 #define TRAP_ILLEGAL_SLOT_INST 6 @@ -575,8 +550,117 @@ int is_dsp_inst(struct pt_regs *regs) #define is_dsp_inst(regs) (0) #endif /* CONFIG_SH_DSP */ -DO_ERROR(TRAP_RESERVED_INST, SIGILL, "reserved instruction", reserved_inst, current) -DO_ERROR(TRAP_ILLEGAL_SLOT_INST, SIGILL, "illegal slot instruction", illegal_slot_inst, current) +extern int do_fpu_inst(unsigned short, struct pt_regs*); + +asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5, + unsigned long r6, unsigned long r7, + struct pt_regs regs) +{ + unsigned long error_code; + struct task_struct *tsk = current; + +#ifdef CONFIG_SH_FPU_EMU + unsigned short inst; + int err; + + get_user(inst, (unsigned short*)regs.pc); + + err = do_fpu_inst(inst, ®s); + if (!err) { + regs.pc += 2; + return; + } + /* not a FPU inst. */ +#endif + +#ifdef CONFIG_SH_DSP + /* Check if it's a DSP instruction */ + if (is_dsp_inst(®s)) { + /* Enable DSP mode, and restart instruction. */ + regs.sr |= SR_DSP; + return; + } +#endif + + asm volatile("stc r2_bank, %0": "=r" (error_code)); + local_irq_enable(); + tsk->thread.error_code = error_code; + tsk->thread.trap_no = TRAP_RESERVED_INST; + CHK_REMOTE_DEBUG(®s); + force_sig(SIGILL, tsk); + die_if_no_fixup("reserved instruction", ®s, error_code); +} + +#ifdef CONFIG_SH_FPU_EMU +static int emulate_branch(unsigned short inst, struct pt_regs* regs) +{ + /* + * bfs: 8fxx: PC+=d*2+4; + * bts: 8dxx: PC+=d*2+4; + * bra: axxx: PC+=D*2+4; + * bsr: bxxx: PC+=D*2+4 after PR=PC+4; + * braf:0x23: PC+=Rn*2+4; + * bsrf:0x03: PC+=Rn*2+4 after PR=PC+4; + * jmp: 4x2b: PC=Rn; + * jsr: 4x0b: PC=Rn after PR=PC+4; + * rts: 000b: PC=PR; + */ + if ((inst & 0xfd00) == 0x8d00) { + regs->pc += SH_PC_8BIT_OFFSET(inst); + return 0; + } + + if ((inst & 0xe000) == 0xa000) { + regs->pc += SH_PC_12BIT_OFFSET(inst); + return 0; + } + + if ((inst & 0xf0df) == 0x0003) { + regs->pc += regs->regs[(inst & 0x0f00) >> 8] + 4; + return 0; + } + + if ((inst & 0xf0df) == 0x400b) { + regs->pc = regs->regs[(inst & 0x0f00) >> 8]; + return 0; + } + + if ((inst & 0xffff) == 0x000b) { + regs->pc = regs->pr; + return 0; + } + + return 1; +} +#endif + +asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5, + unsigned long r6, unsigned long r7, + struct pt_regs regs) +{ + unsigned long error_code; + struct task_struct *tsk = current; +#ifdef CONFIG_SH_FPU_EMU + unsigned short inst; + + get_user(inst, (unsigned short *)regs.pc + 1); + if (!do_fpu_inst(inst, ®s)) { + get_user(inst, (unsigned short *)regs.pc); + if (!emulate_branch(inst, ®s)) + return; + /* fault in branch.*/ + } + /* not a FPU inst. */ +#endif + + asm volatile("stc r2_bank, %0": "=r" (error_code)); + local_irq_enable(); + tsk->thread.error_code = error_code; + tsk->thread.trap_no = TRAP_RESERVED_INST; + CHK_REMOTE_DEBUG(®s); + force_sig(SIGILL, tsk); + die_if_no_fixup("illegal slot instruction", ®s, error_code); +} asmlinkage void do_exception_error(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7, @@ -634,14 +718,16 @@ void __init trap_init(void) exception_handling_table[TRAP_ILLEGAL_SLOT_INST] = (void *)do_illegal_slot_inst; -#ifdef CONFIG_CPU_SH4 - if (!(cpu_data->flags & CPU_HAS_FPU)) { - /* For SH-4 lacking an FPU, treat floating point instructions - as reserved. */ - /* entry 64 corresponds to EXPEVT=0x800 */ - exception_handling_table[64] = (void *)do_reserved_inst; - exception_handling_table[65] = (void *)do_illegal_slot_inst; - } +#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \ + defined(CONFIG_SH_FPU_EMU) + /* + * For SH-4 lacking an FPU, treat floating point instructions as + * reserved. They'll be handled in the math-emu case, or faulted on + * otherwise. + */ + /* entry 64 corresponds to EXPEVT=0x800 */ + exception_handling_table[64] = (void *)do_reserved_inst; + exception_handling_table[65] = (void *)do_illegal_slot_inst; #endif /* Setup VBR for boot cpu */ -- cgit v1.2.3-59-g8ed1b