[SPARC64]: %l6 trap return handling no longer necessary.

Now that we indicate the "restart system call" in the
trap type field of pt_regs->magic, we don't need to
set the %l6 boolean in all of the trap return paths.

And we therefore don't need to pass it to do_notify_resume().

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/entry.S

@@ -47,7 +47,7 @@ do_fpdis:
 	ba,pt		%xcc, etrap
 109:	 or		%g7, %lo(109b), %g7
 	add		%g0, %g0, %g0
-	ba,a,pt		%xcc, rtrap_clr_l6
+	ba,a,pt		%xcc, rtrap
 
 1:	TRAP_LOAD_THREAD_REG(%g6, %g1)
 	ldub		[%g6 + TI_FPSAVED], %g5
@@ -226,7 +226,7 @@ fp_other_bounce:
 	call		do_fpother
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	.globl		do_fpother_check_fitos
 	.align		32
@@ -489,7 +489,7 @@ utrap_trap:		/* %g3=handler,%g4=level */
         call		bad_trap
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 invoke_utrap:
 	sllx		%g3, 3, %g3
@@ -607,7 +607,7 @@ __spitfire_cee_trap_continue:
 	call		spitfire_access_error
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	/* This is the trap handler entry point for ECC correctable
 	 * errors.  They are corrected, but we listen for the trap
@@ -686,7 +686,7 @@ __spitfire_data_access_exception_tl1:
 	call		spitfire_data_access_exception_tl1
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 __spitfire_data_access_exception:
 	rdpr		%pstate, %g4
@@ -705,7 +705,7 @@ __spitfire_data_access_exception:
 	call		spitfire_data_access_exception
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	.globl		__spitfire_insn_access_exception
 	.globl		__spitfire_insn_access_exception_tl1
@@ -725,7 +725,7 @@ __spitfire_insn_access_exception_tl1:
 	call		spitfire_insn_access_exception_tl1
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 __spitfire_insn_access_exception:
 	rdpr		%pstate, %g4
@@ -743,7 +743,7 @@ __spitfire_insn_access_exception:
 	call		spitfire_insn_access_exception
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	/* These get patched into the trap table at boot time
 	 * once we know we have a cheetah processor.
@@ -937,7 +937,7 @@ do_dcpe_tl1_fatal:
 	call		cheetah_plus_parity_error
 	 add		%sp, PTREGS_OFF, %o1
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 do_icpe_tl1:
 	rdpr		%tl, %g1		! Save original trap level
@@ -979,7 +979,7 @@ do_icpe_tl1_fatal:
 	call		cheetah_plus_parity_error
 	 add		%sp, PTREGS_OFF, %o1
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 	
 dcpe_icpe_tl1_common:
 	/* Flush D-cache, re-enable D/I caches in DCU and finally
@@ -1281,7 +1281,7 @@ __do_privact:
 	call		do_privact
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	.globl		do_mna
 do_mna:
@@ -1308,7 +1308,7 @@ do_mna:
 	call		mem_address_unaligned
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	.globl		do_lddfmna
 do_lddfmna:
@@ -1326,7 +1326,7 @@ do_lddfmna:
 	call		handle_lddfmna
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	.globl		do_stdfmna
 do_stdfmna:
@@ -1344,7 +1344,7 @@ do_stdfmna:
 	call		handle_stdfmna
 	 add		%sp, PTREGS_OFF, %o0
 	ba,pt		%xcc, rtrap
-	 clr		%l6
+	 nop
 
 	.globl	breakpoint_trap
 breakpoint_trap:
@@ -1424,13 +1424,13 @@ sys32_rt_sigreturn:
 1:		ldx		[%curptr + TI_FLAGS], %l5
 		andcc		%l5, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT), %g0
 		be,pt		%icc, rtrap
-		 clr		%l6
+		 nop
 		add		%sp, PTREGS_OFF, %o0
 		call		syscall_trace
 		 mov		1, %o1
 
 		ba,pt		%xcc, rtrap
-		 clr		%l6
+		 nop
 
 	/* This is how fork() was meant to be done, 8 instruction entry.
 	 *
@@ -1605,7 +1605,7 @@ ret_sys_call:
 	bne,pn		%icc, linux_syscall_trace2
 	 add		%l1, 0x4, %l2			! npc = npc+4
 	stx		%l1, [%sp + PTREGS_OFF + PT_V9_TPC]
-	ba,pt		%xcc, rtrap_clr_l6
+	ba,pt		%xcc, rtrap
 	 stx		%l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
 
 1:
@@ -1616,7 +1616,6 @@ ret_sys_call:
 	sub		%g0, %o0, %o0
 	or		%g3, %g2, %g3
 	stx		%o0, [%sp + PTREGS_OFF + PT_V9_I0]
-	mov		1, %l6
 	stx		%g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]
 	bne,pn		%icc, linux_syscall_trace2
 	 add		%l1, 0x4, %l2			! npc = npc+4

arch/sparc64/kernel/entry.h

@@ -20,7 +20,6 @@ extern void timer_interrupt(int irq, struct pt_regs *regs);
 
 extern void do_notify_resume(struct pt_regs *regs,
 			     unsigned long orig_i0,
-			     int restart_syscall,
 			     unsigned long thread_info_flags);
 
 extern asmlinkage void syscall_trace(struct pt_regs *regs,

arch/sparc64/kernel/rtrap.S

@@ -18,12 +18,6 @@
 #define		RTRAP_PSTATE_IRQOFF	(PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV)
 #define		RTRAP_PSTATE_AG_IRQOFF	(PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_AG)
 
-		/* Register %l6 keeps track of whether we are returning
-		 * from a system call or not.  It is cleared if we call
-		 * do_notify_resume, and it must not be otherwise modified
-		 * until we fully commit to returning to userspace.
-		 */
-
 		.text
 		.align			32
 __handle_softirq:
@@ -56,14 +50,12 @@ __handle_user_windows:
 		be,pt			%xcc, __handle_user_windows_continue
 		 nop
 		mov			%l5, %o1
-		mov			%l6, %o2
 		add			%sp, PTREGS_OFF, %o0
-		mov			%l0, %o3
+		mov			%l0, %o2
 
 		call			do_notify_resume
 		 wrpr			%g0, RTRAP_PSTATE, %pstate
 		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
-		clr			%l6
 		/* Signal delivery can modify pt_regs tstate, so we must
 		 * reload it.
 		 */
@@ -99,14 +91,12 @@ __handle_perfctrs:
 		be,pt			%xcc, __handle_perfctrs_continue
 		 sethi			%hi(TSTATE_PEF), %o0
 		mov			%l5, %o1
-		mov			%l6, %o2
 		add			%sp, PTREGS_OFF, %o0
-		mov			%l0, %o3
+		mov			%l0, %o2
 		call			do_notify_resume
 
 		 wrpr			%g0, RTRAP_PSTATE, %pstate
 		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
-		clr			%l6
 		/* Signal delivery can modify pt_regs tstate, so we must
 		 * reload it.
 		 */
@@ -127,13 +117,11 @@ __handle_userfpu:
 
 __handle_signal:
 		mov			%l5, %o1
-		mov			%l6, %o2
 		add			%sp, PTREGS_OFF, %o0
-		mov			%l0, %o3
+		mov			%l0, %o2
 		call			do_notify_resume
 		 wrpr			%g0, RTRAP_PSTATE, %pstate
 		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
-		clr			%l6
 
 		/* Signal delivery can modify pt_regs tstate, so we must
 		 * reload it.
@@ -145,9 +133,8 @@ __handle_signal:
 		 andn			%l1, %l4, %l1
 
 		.align			64
-		.globl			rtrap_irq, rtrap_clr_l6, rtrap, irqsz_patchme, rtrap_xcall
+		.globl			rtrap_irq, rtrap, irqsz_patchme, rtrap_xcall
 rtrap_irq:
-rtrap_clr_l6:	clr			%l6
 rtrap:
 #ifndef CONFIG_SMP
 		sethi			%hi(per_cpu____cpu_data), %l0

arch/sparc64/kernel/signal.c

@@ -580,8 +580,7 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 	}
 }
 
-void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall,
-		      unsigned long thread_info_flags)
+void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
 {
 	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 		do_signal(regs, orig_i0);

arch/sparc64/kernel/sun4v_tlb_miss.S

@@ -262,7 +262,7 @@ sun4v_iacc:
 	mov	%l5, %o2
 	call	sun4v_insn_access_exception
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	/* Instruction Access Exception, tl1. */
 sun4v_iacc_tl1:
@@ -278,7 +278,7 @@ sun4v_iacc_tl1:
 	mov	%l5, %o2
 	call	sun4v_insn_access_exception_tl1
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	/* Data Access Exception, tl0. */
 sun4v_dacc:
@@ -294,7 +294,7 @@ sun4v_dacc:
 	mov	%l5, %o2
 	call	sun4v_data_access_exception
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	/* Data Access Exception, tl1. */
 sun4v_dacc_tl1:
@@ -310,7 +310,7 @@ sun4v_dacc_tl1:
 	mov	%l5, %o2
 	call	sun4v_data_access_exception_tl1
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	/* Memory Address Unaligned.  */
 sun4v_mna:
@@ -344,7 +344,7 @@ sun4v_mna:
 	mov	%l5, %o2
 	call	sun4v_do_mna
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	/* Privileged Action.  */
 sun4v_privact:
@@ -352,7 +352,7 @@ sun4v_privact:
 	 rd	%pc, %g7
 	call	do_privact
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	/* Unaligned ldd float, tl0. */
 sun4v_lddfmna:
@@ -368,7 +368,7 @@ sun4v_lddfmna:
 	mov	%l5, %o2
 	call	handle_lddfmna
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	/* Unaligned std float, tl0. */
 sun4v_stdfmna:
@@ -384,7 +384,7 @@ sun4v_stdfmna:
 	mov	%l5, %o2
 	call	handle_stdfmna
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 #define BRANCH_ALWAYS	0x10680000
 #define NOP		0x01000000

arch/sparc64/kernel/tsb.S

@@ -275,7 +275,7 @@ sparc64_realfault_common:
 	stx	%l5, [%g6 + TI_FAULT_ADDR]	! Save fault address
 	call	do_sparc64_fault		! Call fault handler
 	 add	%sp, PTREGS_OFF, %o0		! Compute pt_regs arg
-	ba,pt	%xcc, rtrap_clr_l6		! Restore cpu state
+	ba,pt	%xcc, rtrap			! Restore cpu state
 	 nop					! Delay slot (fill me)
 
 winfix_trampoline:

arch/sparc64/kernel/winfixup.S

@@ -32,7 +32,7 @@ fill_fixup:
 	 rd	%pc, %g7
 	call	do_sparc64_fault
 	 add	%sp, PTREGS_OFF, %o0
-	ba,pt	%xcc, rtrap_clr_l6
+	ba,pt	%xcc, rtrap
 	 nop
 
 	/* Be very careful about usage of the trap globals here.
@@ -100,7 +100,7 @@ spill_fixup_dax:
 	 rd	%pc, %g7
 	call	do_sparc64_fault
 	 add	%sp, PTREGS_OFF, %o0
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 winfix_mna:
 	andn	%g3, 0x7f, %g3
@@ -122,12 +122,12 @@ fill_fixup_mna:
 	mov	%l4, %o2
 	call	sun4v_do_mna
 	 mov	%l5, %o1
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 1:	mov	%l4, %o1
 	mov	%l5, %o2
 	call	mem_address_unaligned
 	 nop
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 winfix_dax:
 	andn	%g3, 0x7f, %g3
@@ -150,7 +150,7 @@ fill_fixup_dax:
 	 add	%sp, PTREGS_OFF, %o0
 	call	sun4v_data_access_exception
 	 nop
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 1:	call	spitfire_data_access_exception
 	 nop
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap

arch/sparc64/mm/ultra.S

@@ -476,7 +476,6 @@ xcall_sync_tick:
 #endif
 	call		smp_synchronize_tick_client
 	 nop
-	clr		%l6
 	b		rtrap_xcall
 	 ldx		[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
 
@@ -511,7 +510,6 @@ xcall_report_regs:
 #endif
 	call		__show_regs
 	 add		%sp, PTREGS_OFF, %o0
-	clr		%l6
 	/* Has to be a non-v9 branch due to the large distance. */
 	b		rtrap_xcall
 	 ldx		[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
@@ -576,7 +574,7 @@ __hypervisor_tlb_xcall_error:
 	mov	%l4, %o0
 	call	hypervisor_tlbop_error_xcall
 	 mov	%l5, %o1
-	ba,a,pt	%xcc, rtrap_clr_l6
+	ba,a,pt	%xcc, rtrap
 
 	.globl		__hypervisor_xcall_flush_tlb_mm
 __hypervisor_xcall_flush_tlb_mm: /* 21 insns */

include/asm-sparc64/ttable.h

@@ -28,7 +28,7 @@
 	call	routine;				\
 	 add	%sp, PTREGS_OFF, %o0;			\
 	ba,pt	%xcc, rtrap;				\
-	 clr	%l6;					\
+	 nop;						\
 	nop;
 
 #define TRAP_7INSNS(routine)				\
@@ -38,7 +38,7 @@
 	call	routine;				\
 	 add	%sp, PTREGS_OFF, %o0;			\
 	ba,pt	%xcc, rtrap;				\
-	 clr	%l6;
+	 nop;
 
 #define TRAP_SAVEFPU(routine)				\
 	sethi	%hi(109f), %g7;				\
@@ -47,7 +47,7 @@
 	call	routine;				\
 	 add	%sp, PTREGS_OFF, %o0;			\
 	ba,pt	%xcc, rtrap;				\
-	 clr	%l6;					\
+	 nop;						\
 	nop;
 
 #define TRAP_NOSAVE(routine)				\
@@ -67,7 +67,7 @@
 	call	routine;				\
 	 add	%sp, PTREGS_OFF, %o0;			\
 	ba,pt	%xcc, rtrap;				\
-	 clr	%l6;					\
+	 nop;						\
 	nop;
 	
 #define TRAP_ARG(routine, arg)				\
@@ -78,7 +78,7 @@
 	call	routine;				\
 	 mov	arg, %o1;				\
 	ba,pt	%xcc, rtrap;				\
-	 clr	%l6;
+	 nop;
 	
 #define TRAPTL1_ARG(routine, arg)			\
 	sethi	%hi(109f), %g7;				\
@@ -88,7 +88,7 @@
 	call	routine;				\
 	 mov	arg, %o1;				\
 	ba,pt	%xcc, rtrap;				\
-	 clr	%l6;
+	 nop;
 	
 #define SYSCALL_TRAP(routine, systbl)			\
 	sethi	%hi(109f), %g7;				\
@@ -166,7 +166,7 @@
 	ldx	[%sp + PTREGS_OFF + PT_V9_TNPC], %l1;			\
 	add	%l1, 4, %l2;						\
 	stx	%l1, [%sp + PTREGS_OFF + PT_V9_TPC];			\
-	ba,pt	%xcc, rtrap_clr_l6;					\
+	ba,pt	%xcc, rtrap;						\
 	 stx	%l2, [%sp + PTREGS_OFF + PT_V9_TNPC];
 	        
 #ifdef CONFIG_KPROBES