x86/fpu: Split out the boot time FPU init code into fpu/init.c

Move boot time FPU initialization code into init.c, to better
isolate it into its own domain.

Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/fpu/Makefile b/arch/x86/kernel/fpu/Makefile
index 89fd66a4b3a15d7de673e86e01ac3577eae8d50b..50464a716b87c707b16c76ea839db0467d4f1c82 100644 (file)
--- a/arch/x86/kernel/fpu/Makefile
+++ b/arch/x86/kernel/fpu/Makefile
@@ -2,4 +2,4 @@
 # Build rules for the FPU support code:
 #
 
-obj-y                          += core.o xsave.o
+obj-y                          += init.o core.o xsave.o

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 01101553c6c1767c1923004bfc1a4042ebd05928..9866a580952ffeabe7173edbec18c9c229723ed4 100644 (file)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -139,94 +139,6 @@ void fpu__save(struct task_struct *tsk)
 }
 EXPORT_SYMBOL_GPL(fpu__save);
 
-unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
-unsigned int xstate_size;
-EXPORT_SYMBOL_GPL(xstate_size);
-static struct i387_fxsave_struct fx_scratch;
-
-static void mxcsr_feature_mask_init(void)
-{
-       unsigned long mask = 0;
-
-       if (cpu_has_fxsr) {
-               memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
-               asm volatile("fxsave %0" : "+m" (fx_scratch));
-               mask = fx_scratch.mxcsr_mask;
-               if (mask == 0)
-                       mask = 0x0000ffbf;
-       }
-       mxcsr_feature_mask &= mask;
-}
-
-static void fpstate_xstate_init_size(void)
-{
-       /*
-        * Note that xstate_size might be overwriten later during
-        * xsave_init().
-        */
-
-       if (!cpu_has_fpu) {
-               /*
-                * 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);
-       else
-               xstate_size = sizeof(struct i387_fsave_struct);
-}
-
-/*
- * Called on the boot CPU at bootup to set up the initial FPU state that
- * is later cloned into all processes.
- *
- * Also called on secondary CPUs to set up the FPU state of their
- * idle threads.
- */
-void fpu__cpu_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)
-               cr4_mask |= X86_CR4_OSXMMEXCPT;
-       if (cr4_mask)
-               cr4_set_bits(cr4_mask);
-
-       cr0 = read_cr0();
-       cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */
-       if (!cpu_has_fpu)
-               cr0 |= X86_CR0_EM;
-       write_cr0(cr0);
-
-       /*
-        * fpstate_xstate_init_size() is only called once, to avoid overriding
-        * 'xstate_size' during (secondary CPU) bootup or during CPU hotplug.
-        */
-       if (xstate_size == 0)
-               fpstate_xstate_init_size();
-
-       mxcsr_feature_mask_init();
-       xsave_init();
-       eager_fpu_init();
-}
-
 void fpstate_init(struct fpu *fpu)
 {
        if (!cpu_has_fpu) {

diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
new file mode 100644 (file)
index 0000000..0a66629
--- /dev/null
+++ b/arch/x86/kernel/fpu/init.c
@@ -0,0 +1,93 @@
+/*
+ * x86 FPU boot time init code
+ */
+#include <asm/fpu-internal.h>
+#include <asm/tlbflush.h>
+
+unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
+unsigned int xstate_size;
+EXPORT_SYMBOL_GPL(xstate_size);
+static struct i387_fxsave_struct fx_scratch;
+
+static void mxcsr_feature_mask_init(void)
+{
+       unsigned long mask = 0;
+
+       if (cpu_has_fxsr) {
+               memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
+               asm volatile("fxsave %0" : "+m" (fx_scratch));
+               mask = fx_scratch.mxcsr_mask;
+               if (mask == 0)
+                       mask = 0x0000ffbf;
+       }
+       mxcsr_feature_mask &= mask;
+}
+
+static void fpstate_xstate_init_size(void)
+{
+       /*
+        * Note that xstate_size might be overwriten later during
+        * xsave_init().
+        */
+
+       if (!cpu_has_fpu) {
+               /*
+                * 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);
+       else
+               xstate_size = sizeof(struct i387_fsave_struct);
+}
+
+/*
+ * Called on the boot CPU at bootup to set up the initial FPU state that
+ * is later cloned into all processes.
+ *
+ * Also called on secondary CPUs to set up the FPU state of their
+ * idle threads.
+ */
+void fpu__cpu_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)
+               cr4_mask |= X86_CR4_OSXMMEXCPT;
+       if (cr4_mask)
+               cr4_set_bits(cr4_mask);
+
+       cr0 = read_cr0();
+       cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */
+       if (!cpu_has_fpu)
+               cr0 |= X86_CR0_EM;
+       write_cr0(cr0);
+
+       /*
+        * fpstate_xstate_init_size() is only called once, to avoid overriding
+        * 'xstate_size' during (secondary CPU) bootup or during CPU hotplug.
+        */
+       if (xstate_size == 0)
+               fpstate_xstate_init_size();
+
+       mxcsr_feature_mask_init();
+       xsave_init();
+       eager_fpu_init();
+}