[patch V2 08/13] x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall

[Thomas Gleixner]

From: Thomas Gleixner <t...@linutronix.de>

To avoid yet another macro implementation reuse the existing
run_sysvec_on_irqstack_cond() and move the set_irq_regs() handling into the
called function. Makes the code even simpler.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Reviewed-by: Kees Cook <keesc...@chromium.org>

---
 arch/x86/entry/common.c |   19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -249,30 +249,23 @@ static __always_inline bool get_and_clea
 static __always_inline void restore_inhcall(bool inhcall) { }
 #endif
 
-static void __xen_pv_evtchn_do_upcall(void)
+static void __xen_pv_evtchn_do_upcall(struct pt_regs *regs)
 {
-       irq_enter_rcu();
+       struct pt_regs *old_regs = set_irq_regs(regs);
+
        inc_irq_stat(irq_hv_callback_count);
 
        xen_hvm_evtchn_do_upcall();
 
-       irq_exit_rcu();
+       set_irq_regs(old_regs);
 }
 
 __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)
 {
-       struct pt_regs *old_regs;
+       irqentry_state_t state = irqentry_enter(regs);
        bool inhcall;
-       irqentry_state_t state;
-
-       state = irqentry_enter(regs);
-       old_regs = set_irq_regs(regs);
 
-       instrumentation_begin();
-       run_on_irqstack_cond(__xen_pv_evtchn_do_upcall, regs);
-       instrumentation_end();
-
-       set_irq_regs(old_regs);
+       run_sysvec_on_irqstack_cond(__xen_pv_evtchn_do_upcall, regs);
 
        inhcall = get_and_clear_inhcall();
        if (inhcall && !WARN_ON_ONCE(state.exit_rcu)) {