From 689ee8565c5b5af9369f4c34af04196f2d3fea83 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Mon, 27 Jul 2015 12:58:13 -0700 Subject: [PATCH] MIPS: Simplify EVA FP context handling code The protected_{save,restore}_fp_context functions had effectively different implementations for EVA. Simplify & unify the code somewhat such that EVA configurations simply guarantee the FPU-not-owned path through the standard code path. Signed-off-by: Paul Burton Cc: Markos Chandras Cc: linux-mips@linux-mips.org Cc: Guenter Roeck Cc: Matthew Fortune Cc: Michael Ellerman Cc: linux-kernel@vger.kernel.org Cc: Richard Weinberger Cc: Andy Lutomirski Cc: Maciej W. Rozycki Patchwork: https://patchwork.linux-mips.org/patch/10787/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/signal.c | 44 +++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 25 deletions(-) diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 6a28c792d862..796c7d856d7d 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -101,7 +101,14 @@ static int copy_fp_from_sigcontext(struct sigcontext __user *sc) static int protected_save_fp_context(struct sigcontext __user *sc) { int err; -#ifndef CONFIG_EVA + + /* + * EVA does not have userland equivalents of ldc1 or sdc1, so + * save to the kernel FP context & copy that to userland below. + */ + if (config_enabled(CONFIG_EVA)) + lose_fpu(1); + while (1) { lock_fpu_owner(); if (is_fpu_owner()) { @@ -120,21 +127,22 @@ static int protected_save_fp_context(struct sigcontext __user *sc) if (err) break; /* really bad sigcontext */ } -#else - /* - * EVA does not have FPU EVA instructions so saving fpu context directly - * does not work. - */ - lose_fpu(1); - err = save_fp_context(sc); /* this might fail */ -#endif + return err; } static int protected_restore_fp_context(struct sigcontext __user *sc) { int err, tmp __maybe_unused; -#ifndef CONFIG_EVA + + /* + * EVA does not have userland equivalents of ldc1 or sdc1, so we + * disable the FPU here such that the code below simply copies to + * the kernel FP context. + */ + if (config_enabled(CONFIG_EVA)) + lose_fpu(0); + while (1) { lock_fpu_owner(); if (is_fpu_owner()) { @@ -153,14 +161,7 @@ static int protected_restore_fp_context(struct sigcontext __user *sc) if (err) break; /* really bad sigcontext */ } -#else - /* - * EVA does not have FPU EVA instructions so restoring fpu context - * directly does not work. - */ - lose_fpu(0); - err = restore_fp_context(sc); /* this might fail */ -#endif + return err; } @@ -629,7 +630,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, } #ifdef CONFIG_SMP -#ifndef CONFIG_EVA static int smp_save_fp_context(struct sigcontext __user *sc) { return raw_cpu_has_fpu @@ -643,12 +643,10 @@ static int smp_restore_fp_context(struct sigcontext __user *sc) ? _restore_fp_context(sc) : copy_fp_from_sigcontext(sc); } -#endif /* CONFIG_EVA */ #endif static int signal_setup(void) { -#ifndef CONFIG_EVA #ifdef CONFIG_SMP /* For now just do the cpu_has_fpu check when the functions are invoked */ save_fp_context = smp_save_fp_context; @@ -662,10 +660,6 @@ static int signal_setup(void) restore_fp_context = copy_fp_from_sigcontext; } #endif /* CONFIG_SMP */ -#else - save_fp_context = copy_fp_to_sigcontext; - restore_fp_context = copy_fp_from_sigcontext; -#endif return 0; } -- 2.20.1