[PATCH RFC 27/28] ARM: entry: Add FIQ/NMI C callbacks

[Linus Walleij]

These NMI (FIQ) callbacks are added to complete the calls expected
by the generic entry. They are perfectly fine to add code to
but are left empty for now.

Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
 arch/arm/include/asm/entry.h   |  4 ++++
 arch/arm/kernel/entry-armv.S   | 14 +++++++++++---
 arch/arm/kernel/entry-header.S |  2 ++
 arch/arm/kernel/entry.c        | 16 ++++++++++++++++
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/entry.h b/arch/arm/include/asm/entry.h
index a78bc5054b09..2e7ccd87f0eb 100644
--- a/arch/arm/include/asm/entry.h
+++ b/arch/arm/include/asm/entry.h
@@ -14,5 +14,9 @@ void irqentry_enter_from_user_mode(struct pt_regs *regs);
 void irqentry_exit_to_user_mode(struct pt_regs *regs);
 void irqentry_enter_from_kernel_mode(struct pt_regs *regs);
 void irqentry_exit_to_kernel_mode(struct pt_regs *regs);
+void irqentry_nmi_enter_from_user_mode(struct pt_regs *regs);
+void irqentry_nmi_exit_to_user_mode(struct pt_regs *regs);
+void irqentry_nmi_enter_from_kernel_mode(struct pt_regs *regs);
+void irqentry_nmi_exit_to_kernel_mode(struct pt_regs *regs);
 
 #endif /* __ASM_ENTRY_H__ */
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 600375f6f5d8..839f3ebe7228 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -157,7 +157,7 @@ ENDPROC(__und_invalid)
 #define SPFIX(code...)
 #endif
 
-	.macro	svc_entry, stack_hole=0 uaccess=1, overflow_check=1
+	.macro	svc_entry, stack_hole=0 uaccess=1, overflow_check=1, nmi=0
  UNWIND(.fnstart		)
 	sub	sp, sp, #(SVC_REGS_SIZE + \stack_hole)
  THUMB(	add	sp, r1		)	@ get SP in a GPR without
@@ -205,7 +205,11 @@ ENDPROC(__und_invalid)
 	uaccess_entry tsk, r0, r1, r2, \uaccess
 
 	mov	r0, sp				@ 'regs'
+	.if \nmi
+	bl	irqentry_nmi_enter_from_kernel_mode
+	.else
 	bl	irqentry_enter_from_kernel_mode
+	.endif
 
 	.endm
 
@@ -297,7 +301,7 @@ ENDPROC(__pabt_svc)
 
 	.align	5
 __fiq_svc:
-	svc_entry
+	svc_entry nmi=1
 	mov	r0, sp				@ struct pt_regs *regs
 	bl	handle_fiq_as_nmi
 	svc_exit_via_fiq
@@ -315,7 +319,7 @@ ENDPROC(__fiq_svc)
 @
 	.align 5
 __fiq_abt:
-	svc_entry
+	svc_entry nmi=1
 
  ARM(	msr	cpsr_c, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
  THUMB( mov	r0, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
@@ -490,9 +494,13 @@ ENDPROC(ret_from_exception)
 	.align	5
 __fiq_usr:
 	usr_entry
+	mov	r0, sp
+	bl	irqentry_nmi_enter_from_user_mode
 	kuser_cmpxchg_check
 	mov	r0, sp				@ struct pt_regs *regs
 	bl	handle_fiq_as_nmi
+	mov	r0, sp
+	bl	irqentry_nmi_exit_to_user_mode
 	get_thread_info tsk
 	restore_user_regs
  UNWIND(.fnend		)
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index cfaf14d71378..ec8a6e193802 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -252,6 +252,8 @@
 	@
 	.macro  svc_exit_via_fiq
 	uaccess_exit tsk, r0, r1
+	mov	r0, sp
+	bl	irqentry_nmi_exit_to_kernel_mode
 #ifndef CONFIG_THUMB2_KERNEL
 	@ ARM mode restore
 	mov	r0, sp
diff --git a/arch/arm/kernel/entry.c b/arch/arm/kernel/entry.c
index 1e1284cc4cae..09109215dfdf 100644
--- a/arch/arm/kernel/entry.c
+++ b/arch/arm/kernel/entry.c
@@ -69,3 +69,19 @@ noinstr void irqentry_exit_to_kernel_mode(struct pt_regs *regs)
 	else
 		trace_hardirqs_off();
 }
+
+noinstr void irqentry_nmi_enter_from_user_mode(struct pt_regs *regs)
+{
+}
+
+noinstr void irqentry_nmi_exit_to_user_mode(struct pt_regs *regs)
+{
+}
+
+noinstr void irqentry_nmi_enter_from_kernel_mode(struct pt_regs *regs)
+{
+}
+
+noinstr void irqentry_nmi_exit_to_kernel_mode(struct pt_regs *regs)
+{
+}

-- 
2.46.2