arm64: entry: Clean out some indirection

The conversion to generic IRQ entry left some functions
in the EL1 (kernel) IRQ entry path very shallow, so drop
the __inner_functions() where appropriate, saving some
time and stack.

This is not a fix but an optimization.

Drop stale comments about irqentry_enter/exit() while we
are at it.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: Linus Walleij

arch/arm64/kernel/entry-common.c

@@ -34,20 +34,12 @@
  * Handle IRQ/context state management when entering from kernel mode.
  * Before this function is called it is not safe to call regular kernel code,
  * instrumentable code, or any code which may trigger an exception.
- *
- * This is intended to match the logic in irqentry_enter(), handling the kernel
- * mode transitions only.
  */
-static __always_inline irqentry_state_t __enter_from_kernel_mode(struct pt_regs *regs)
-{
-	return irqentry_enter(regs);
-}
-
 static noinstr irqentry_state_t enter_from_kernel_mode(struct pt_regs *regs)
 {
 	irqentry_state_t state;
 
-	state = __enter_from_kernel_mode(regs);
+	state = irqentry_enter(regs);
 	mte_check_tfsr_entry();
 	mte_disable_tco_entry(current);
 
@@ -58,39 +50,25 @@ static noinstr irqentry_state_t enter_from_kernel_mode(struct pt_regs *regs)
  * Handle IRQ/context state management when exiting to kernel mode.
  * After this function returns it is not safe to call regular kernel code,
  * instrumentable code, or any code which may trigger an exception.
- *
- * This is intended to match the logic in irqentry_exit(), handling the kernel
- * mode transitions only, and with preemption handled elsewhere.
  */
-static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs,
-						  irqentry_state_t state)
-{
-	irqentry_exit(regs, state);
-}
-
 static void noinstr exit_to_kernel_mode(struct pt_regs *regs,
 					irqentry_state_t state)
 {
 	mte_check_tfsr_exit();
-	__exit_to_kernel_mode(regs, state);
+	irqentry_exit(regs, state);
 }
 
 /*
  * Handle IRQ/context state management when entering from user mode.
  * Before this function is called it is not safe to call regular kernel code,
  * instrumentable code, or any code which may trigger an exception.
  */
-static __always_inline void __enter_from_user_mode(struct pt_regs *regs)
+static __always_inline void arm64_enter_from_user_mode(struct pt_regs *regs)
 {
 	enter_from_user_mode(regs);
 	mte_disable_tco_entry(current);
 }
 
-static __always_inline void arm64_enter_from_user_mode(struct pt_regs *regs)
-{
-	__enter_from_user_mode(regs);
-}
-
 /*
  * Handle IRQ/context state management when exiting to user mode.
  * After this function returns it is not safe to call regular kernel code,