[tip: x86/entry] x86/entry/64: Move do_softirq_own_stack() to C

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the x86/entry branch of tip:

Commit-ID:     4f41db23ef2593aec26e23e7f4bacc620e82f545
Gitweb:        https://git.kernel.org/tip/4f41db23ef2593aec26e23e7f4bacc620e82f545
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Thu, 21 May 2020 22:05:24 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 26 May 2020 19:06:27 +02:00

x86/entry/64: Move do_softirq_own_stack() to C

The first step to get rid of the ENTER/LEAVE_IRQ_STACK ASM macro maze.  Use
the new C code helpers to move do_softirq_own_stack() out of ASM code.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200521202117.870911120@xxxxxxxxxxxxx
---
 arch/x86/entry/entry_64.S | 13 -------------
 arch/x86/kernel/irq_64.c  |  6 ++++++
 2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1597370..6b518be 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1145,19 +1145,6 @@ SYM_FUNC_START(asm_call_on_stack)
 	ret
 SYM_FUNC_END(asm_call_on_stack)
 
-/* Call softirq on interrupt stack. Interrupts are off. */
-.pushsection .text, "ax"
-SYM_FUNC_START(do_softirq_own_stack)
-	pushq	%rbp
-	mov	%rsp, %rbp
-	ENTER_IRQ_STACK regs=0 old_rsp=%r11
-	call	__do_softirq
-	LEAVE_IRQ_STACK regs=0
-	leaveq
-	ret
-SYM_FUNC_END(do_softirq_own_stack)
-.popsection
-
 #ifdef CONFIG_XEN_PV
 /*
  * A note on the "critical region" in our callback handler.
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 12df3a4..d5f9df4 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -20,6 +20,7 @@
 #include <linux/sched/task_stack.h>
 
 #include <asm/cpu_entry_area.h>
+#include <asm/irq_stack.h>
 #include <asm/io_apic.h>
 #include <asm/apic.h>
 
@@ -70,3 +71,8 @@ int irq_init_percpu_irqstack(unsigned int cpu)
 		return 0;
 	return map_irq_stack(cpu);
 }
+
+void do_softirq_own_stack(void)
+{
+	run_on_irqstack_cond(__do_softirq, NULL, NULL);
+}