diff options
Diffstat (limited to 'arch/x86/kernel/i387.c')
| -rw-r--r-- | arch/x86/kernel/i387.c | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index a46cb3522c0..58bb239a2fd 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -68,19 +68,22 @@ static void __cpuinit init_thread_xstate(void) */ if (!HAVE_HWFP) { + /* + * Disable xsave as we do not support it if i387 + * emulation is enabled. + */ + setup_clear_cpu_cap(X86_FEATURE_XSAVE); + setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); xstate_size = sizeof(struct i387_soft_struct); return; } if (cpu_has_fxsr) xstate_size = sizeof(struct i387_fxsave_struct); -#ifdef CONFIG_X86_32 else xstate_size = sizeof(struct i387_fsave_struct); -#endif } -#ifdef CONFIG_X86_64 /* * Called at bootup to set up the initial FPU state that is later cloned * into all processes. @@ -88,12 +91,21 @@ static void __cpuinit init_thread_xstate(void) void __cpuinit fpu_init(void) { - unsigned long oldcr0 = read_cr0(); - - set_in_cr4(X86_CR4_OSFXSR); - set_in_cr4(X86_CR4_OSXMMEXCPT); + unsigned long cr0; + unsigned long cr4_mask = 0; - write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */ + if (cpu_has_fxsr) + cr4_mask |= X86_CR4_OSFXSR; + if (cpu_has_xmm) + cr4_mask |= X86_CR4_OSXMMEXCPT; + if (cr4_mask) + set_in_cr4(cr4_mask); + + cr0 = read_cr0(); + cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */ + if (!HAVE_HWFP) + cr0 |= X86_CR0_EM; + write_cr0(cr0); if (!smp_processor_id()) init_thread_xstate(); @@ -104,24 +116,12 @@ void __cpuinit fpu_init(void) clear_used_math(); } -#else /* CONFIG_X86_64 */ - -void __cpuinit fpu_init(void) -{ - if (!smp_processor_id()) - init_thread_xstate(); -} - -#endif /* CONFIG_X86_32 */ - void fpu_finit(struct fpu *fpu) { -#ifdef CONFIG_X86_32 if (!HAVE_HWFP) { finit_soft_fpu(&fpu->state->soft); return; } -#endif if (cpu_has_fxsr) { struct i387_fxsave_struct *fx = &fpu->state->fxsave; @@ -386,19 +386,17 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk) #ifdef CONFIG_X86_64 env->fip = fxsave->rip; env->foo = fxsave->rdp; + /* + * should be actually ds/cs at fpu exception time, but + * that information is not available in 64bit mode. + */ + env->fcs = task_pt_regs(tsk)->cs; if (tsk == current) { - /* - * should be actually ds/cs at fpu exception time, but - * that information is not available in 64bit mode. - */ - asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos)); - asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs)); + savesegment(ds, env->fos); } else { - struct pt_regs *regs = task_pt_regs(tsk); - - env->fos = 0xffff0000 | tsk->thread.ds; - env->fcs = regs->cs; + env->fos = tsk->thread.ds; } + env->fos |= 0xffff0000; #else env->fip = fxsave->fip; env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16); |