x86/fpu: Rename math_state_restore() to fpu__restore()

Move to the new fpu__*() namespace.

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>

Documentation/preempt-locking.txt

@@ -48,7 +48,7 @@ preemption must be disabled around such regions.
 
 Note, some FPU functions are already explicitly preempt safe.  For example,
 kernel_fpu_begin and kernel_fpu_end will disable and enable preemption.
-However, math_state_restore must be called with preemption disabled.
+However, fpu__restore() must be called with preemption disabled.
 
 
 RULE #3: Lock acquire and release must be performed by same task

arch/x86/include/asm/i387.h

@@ -23,7 +23,7 @@ extern void fpstate_init(struct fpu *fpu);
 extern void fpu__flush_thread(struct task_struct *tsk);
 
 extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
-extern void math_state_restore(void);
+extern void fpu__restore(void);
 
 extern bool irq_fpu_usable(void);
 

arch/x86/kernel/fpu/core.c

@@ -228,7 +228,7 @@ static int fpu__unlazy_stopped(struct task_struct *child)
 }
 
 /*
- * 'math_state_restore()' saves the current math information in the
+ * 'fpu__restore()' saves the current math information in the
  * old math state array, and gets the new ones from the current task
  *
  * Careful.. There are problems with IBM-designed IRQ13 behaviour.
@@ -237,7 +237,7 @@ static int fpu__unlazy_stopped(struct task_struct *child)
  * Must be called with kernel preemption disabled (eg with local
  * local interrupts as in the case of do_device_not_available).
  */
-void math_state_restore(void)
+void fpu__restore(void)
 {
 	struct task_struct *tsk = current;
 
@@ -267,7 +267,7 @@ void math_state_restore(void)
 	}
 	kernel_fpu_enable();
 }
-EXPORT_SYMBOL_GPL(math_state_restore);
+EXPORT_SYMBOL_GPL(fpu__restore);
 
 void fpu__flush_thread(struct task_struct *tsk)
 {

arch/x86/kernel/fpu/xsave.c

@@ -404,7 +404,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
 		set_used_math();
 		if (use_eager_fpu()) {
 			preempt_disable();
-			math_state_restore();
+			fpu__restore();
 			preempt_enable();
 		}
 

arch/x86/kernel/process_32.c

@@ -295,7 +295,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	 * Leave lazy mode, flushing any hypercalls made here.
 	 * This must be done before restoring TLS segments so
 	 * the GDT and LDT are properly updated, and must be
-	 * done before math_state_restore, so the TS bit is up
+	 * done before fpu__restore(), so the TS bit is up
 	 * to date.
 	 */
 	arch_end_context_switch(next_p);

arch/x86/kernel/process_64.c

@@ -298,7 +298,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	 * Leave lazy mode, flushing any hypercalls made here.  This
 	 * must be done after loading TLS entries in the GDT but before
 	 * loading segments that might reference them, and and it must
-	 * be done before math_state_restore, so the TS bit is up to
+	 * be done before fpu__restore(), so the TS bit is up to
 	 * date.
 	 */
 	arch_end_context_switch(next_p);

arch/x86/kernel/traps.c

@@ -846,7 +846,7 @@ do_device_not_available(struct pt_regs *regs, long error_code)
 		return;
 	}
 #endif
-	math_state_restore(); /* interrupts still off */
+	fpu__restore(); /* interrupts still off */
 #ifdef CONFIG_X86_32
 	conditional_sti(regs);
 #endif

drivers/lguest/x86/core.c

@@ -297,12 +297,12 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
 	/*
 	 * Similarly, if we took a trap because the Guest used the FPU,
 	 * we have to restore the FPU it expects to see.
-	 * math_state_restore() may sleep and we may even move off to
+	 * fpu__restore() may sleep and we may even move off to
 	 * a different CPU. So all the critical stuff should be done
 	 * before this.
 	 */
 	else if (cpu->regs->trapnum == 7 && !user_has_fpu())
-		math_state_restore();
+		fpu__restore();
 }
 
 /*H:130