x86: Get rid of ->hard_math and all the FPU asm fu

[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / i387.c

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index cb339097b9ea0cf4f57b2b406fa308a489cee881..b627746f6b1a81a5fc0c6e9e30adb1bb502f0b87 100644 (file)
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -131,7 +131,7 @@ static void __cpuinit init_thread_xstate(void)
         * xsave_init().
         */
 
-       if (!HAVE_HWFP) {
+       if (!cpu_has_fpu) {
                /*
                 * Disable xsave as we do not support it if i387
                 * emulation is enabled.
@@ -158,6 +158,14 @@ void __cpuinit fpu_init(void)
        unsigned long cr0;
        unsigned long cr4_mask = 0;
 
+#ifndef CONFIG_MATH_EMULATION
+       if (!cpu_has_fpu) {
+               pr_emerg("No FPU found and no math emulation present\n");
+               pr_emerg("Giving up\n");
+               for (;;)
+                       asm volatile("hlt");
+       }
+#endif
        if (cpu_has_fxsr)
                cr4_mask |= X86_CR4_OSFXSR;
        if (cpu_has_xmm)
@@ -167,7 +175,7 @@ void __cpuinit fpu_init(void)
 
        cr0 = read_cr0();
        cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */
-       if (!HAVE_HWFP)
+       if (!cpu_has_fpu)
                cr0 |= X86_CR0_EM;
        write_cr0(cr0);
 
@@ -185,7 +193,7 @@ void __cpuinit fpu_init(void)
 
 void fpu_finit(struct fpu *fpu)
 {
-       if (!HAVE_HWFP) {
+       if (!cpu_has_fpu) {
                finit_soft_fpu(&fpu->state->soft);
                return;
        }
@@ -214,7 +222,7 @@ int init_fpu(struct task_struct *tsk)
        int ret;
 
        if (tsk_used_math(tsk)) {
-               if (HAVE_HWFP && tsk == current)
+               if (cpu_has_fpu && tsk == current)
                        unlazy_fpu(tsk);
                tsk->thread.fpu.last_cpu = ~0;
                return 0;
@@ -511,14 +519,13 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset,
        if (ret)
                return ret;
 
-       if (!HAVE_HWFP)
+       if (!static_cpu_has(X86_FEATURE_FPU))
                return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
 
-       if (!cpu_has_fxsr) {
+       if (!cpu_has_fxsr)
                return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
                                           &target->thread.fpu.state->fsave, 0,
                                           -1);
-       }
 
        sanitize_i387_state(target);
 
@@ -545,13 +552,13 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
 
        sanitize_i387_state(target);
 
-       if (!HAVE_HWFP)
+       if (!static_cpu_has(X86_FEATURE_FPU))
                return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
 
-       if (!cpu_has_fxsr) {
+       if (!cpu_has_fxsr)
                return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-                                         &target->thread.fpu.state->fsave, 0, -1);
-       }
+                                         &target->thread.fpu.state->fsave, 0,
+                                         -1);
 
        if (pos > 0 || count < sizeof(env))
                convert_from_fxsr(&env, target);
@@ -592,3 +599,33 @@ int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
 EXPORT_SYMBOL(dump_fpu);
 
 #endif /* CONFIG_X86_32 || CONFIG_IA32_EMULATION */
+
+static int __init no_387(char *s)
+{
+       setup_clear_cpu_cap(X86_FEATURE_FPU);
+       return 1;
+}
+
+__setup("no387", no_387);
+
+void __cpuinit fpu_detect(struct cpuinfo_x86 *c)
+{
+       unsigned long cr0;
+       u16 fsw, fcw;
+
+       fsw = fcw = 0xffff;
+
+       cr0 = read_cr0();
+       cr0 &= ~(X86_CR0_TS | X86_CR0_EM);
+       write_cr0(cr0);
+
+       asm volatile("fninit ; fnstsw %0 ; fnstcw %1"
+                    : "+m" (fsw), "+m" (fcw));
+
+       if (fsw == 0 && (fcw & 0x103f) == 0x003f)
+               set_cpu_cap(c, X86_FEATURE_FPU);
+       else
+               clear_cpu_cap(c, X86_FEATURE_FPU);
+
+       /* The final cr0 value is set in fpu_init() */
+}