From 3a3b5aa63fad4911e239055c2c0a89ce2dac62ce Mon Sep 17 00:00:00 2001 From: Kevin Hao Date: Sun, 14 Jul 2013 16:40:07 +0800 Subject: [PATCH] powerpc: Introduce function emulate_math() There are two invocations of do_mathemu() in traps.c. And the codes in these two places are almost the same. Introduce a locale function to eliminate the duplication. With this change we can also make sure that in program_check_exception() the PPC_WARN_EMULATED is invoked for the correctly emulated math instructions. Signed-off-by: Kevin Hao Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/traps.c | 79 ++++++++++++++++--------------------- 1 file changed, 34 insertions(+), 45 deletions(-) diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 82df498069bc..e6fac2102b06 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -1055,11 +1055,41 @@ int is_valid_bugaddr(unsigned long addr) return is_kernel_addr(addr); } +#ifdef CONFIG_MATH_EMULATION +static int emulate_math(struct pt_regs *regs) +{ + int ret; + extern int do_mathemu(struct pt_regs *regs); + + ret = do_mathemu(regs); + if (ret >= 0) + PPC_WARN_EMULATED(math, regs); + + switch (ret) { + case 0: + emulate_single_step(regs); + return 0; + case 1: { + int code = 0; + code = __parse_fpscr(current->thread.fpscr.val); + _exception(SIGFPE, regs, code, regs->nip); + return 0; + } + case -EFAULT: + _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); + return 0; + } + + return -1; +} +#else +static inline int emulate_math(struct pt_regs *regs) { return -1; } +#endif + void __kprobes program_check_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); unsigned int reason = get_reason(regs); - extern int do_mathemu(struct pt_regs *regs); /* We can now get here via a FP Unavailable exception if the core * has no FPU, in that case the reason flags will be 0 */ @@ -1125,7 +1155,6 @@ void __kprobes program_check_exception(struct pt_regs *regs) if (!arch_irq_disabled_regs(regs)) local_irq_enable(); -#ifdef CONFIG_MATH_EMULATION /* (reason & REASON_ILLEGAL) would be the obvious thing here, * but there seems to be a hardware bug on the 405GP (RevD) * that means ESR is sometimes set incorrectly - either to @@ -1134,22 +1163,8 @@ void __kprobes program_check_exception(struct pt_regs *regs) * instruction or only on FP instructions, whether there is a * pattern to occurrences etc. -dgibson 31/Mar/2003 */ - switch (do_mathemu(regs)) { - case 0: - emulate_single_step(regs); - goto bail; - case 1: { - int code = 0; - code = __parse_fpscr(current->thread.fpscr.val); - _exception(SIGFPE, regs, code, regs->nip); - goto bail; - } - case -EFAULT: - _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); + if (!emulate_math(regs)) goto bail; - } - /* fall through on any other errors */ -#endif /* CONFIG_MATH_EMULATION */ /* Try to emulate it if we should. */ if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) { @@ -1428,11 +1443,6 @@ void performance_monitor_exception(struct pt_regs *regs) #ifdef CONFIG_8xx void SoftwareEmulation(struct pt_regs *regs) { - extern int do_mathemu(struct pt_regs *); -#if defined(CONFIG_MATH_EMULATION) - int errcode; -#endif - CHECK_FULL_REGS(regs); if (!user_mode(regs)) { @@ -1440,31 +1450,10 @@ void SoftwareEmulation(struct pt_regs *regs) die("Kernel Mode Software FPU Emulation", regs, SIGFPE); } -#ifdef CONFIG_MATH_EMULATION - errcode = do_mathemu(regs); - if (errcode >= 0) - PPC_WARN_EMULATED(math, regs); - - switch (errcode) { - case 0: - emulate_single_step(regs); - return; - case 1: { - int code = 0; - code = __parse_fpscr(current->thread.fpscr.val); - _exception(SIGFPE, regs, code, regs->nip); - return; - } - case -EFAULT: - _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip); + if (!emulate_math(regs)) return; - default: - _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); - return; - } -#else + _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); -#endif } #endif /* CONFIG_8xx */ -- 2.20.1