[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>

9 files changed, 45 insertions, 63 deletions

diff --git a/arch/sparc64/kernel/entry.S b/arch/sparc64/kernel/entry.S
index f54cd2dd55dc..fd06e937ae1e 100644
--- a/arch/sparc64/kernel/entry.S
+++ b/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
diff --git a/arch/sparc64/kernel/entry.h b/arch/sparc64/kernel/entry.h
index 4a91e9c6d31b..32fbab620852 100644
--- a/arch/sparc64/kernel/entry.h
+++ b/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,
diff --git a/arch/sparc64/kernel/rtrap.S b/arch/sparc64/kernel/rtrap.S
index 079d18a11d24..ecf6753b204a 100644
--- a/arch/sparc64/kernel/rtrap.S
+++ b/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
diff --git a/arch/sparc64/kernel/signal.c b/arch/sparc64/kernel/signal.c
index b959597201ed..77a3e8592cbc 100644
--- a/arch/sparc64/kernel/signal.c
+++ b/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);
diff --git a/arch/sparc64/kernel/sun4v_tlb_miss.S b/arch/sparc64/kernel/sun4v_tlb_miss.S
index fd9430562e0b..e1fbf8c75787 100644
--- a/arch/sparc64/kernel/sun4v_tlb_miss.S
+++ b/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
diff --git a/arch/sparc64/kernel/tsb.S b/arch/sparc64/kernel/tsb.S
index 10adb2fb8ffe..c499214b501d 100644
--- a/arch/sparc64/kernel/tsb.S
+++ b/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:
diff --git a/arch/sparc64/kernel/winfixup.S b/arch/sparc64/kernel/winfixup.S
index c4aa110a10e5..a6b0863c27df 100644
--- a/arch/sparc64/kernel/winfixup.S
+++ b/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
diff --git a/arch/sparc64/mm/ultra.S b/arch/sparc64/mm/ultra.S
index 2865c105b6a4..e686a67561af 100644
--- a/arch/sparc64/mm/ultra.S
+++ b/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 */
diff --git a/include/asm-sparc64/ttable.h b/include/asm-sparc64/ttable.h
index 7208a777750e..d3cc4eff39a6 100644
--- a/include/asm-sparc64/ttable.h
+++ b/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