powerpc/64s: Move system_call() symbol to just after setting MSR_EE

It is common to get a PMU interrupt right after the mtmsr instruction that
enables interrupts. Due to this, the stack trace profile gets needlessly split
across system_call_common() and system_call().

Previously, system_call() symbol was at the current place to hide a few
earlier symbols which have since been made private or removed entirely.

So, let's move system_call() slightly higher up, right after the mtmsr
instruction that enables interrupts. Convert existing references to
system_call to a local syscall symbol.

Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 410e19295259b2aa81d59c0b019098b43724daf0..e5cf98d755dbd855afff4f3743add45eba730091 100644 (file)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -143,6 +143,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
        mtmsrd  r11,1
 #endif /* CONFIG_PPC_BOOK3E */
 
+system_call:                   /* label this so stack traces look sane */
        /* We do need to set SOFTE in the stack frame or the return
         * from interrupt will be painful
         */
@@ -156,7 +157,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
        cmpldi  0,r0,NR_syscalls
        bge-    .Lsyscall_enosys
 
-system_call:                   /* label this so stack traces look sane */
+.Lsyscall:
 /*
  * Need to vector to 32 Bit or default sys_call_table here,
  * based on caller's run-mode / personality.
@@ -310,13 +311,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
        ld      r7,GPR7(r1)
        ld      r8,GPR8(r1)
 
-       /* Repopulate r9 and r10 for the system_call path */
+       /* Repopulate r9 and r10 for the syscall path */
        addi    r9,r1,STACK_FRAME_OVERHEAD
        CURRENT_THREAD_INFO(r10, r1)
        ld      r10,TI_FLAGS(r10)
 
        cmpldi  r0,NR_syscalls
-       blt+    system_call
+       blt+    .Lsyscall
 
        /* Return code is already in r3 thanks to do_syscall_trace_enter() */
        b       .Lsyscall_exit